Spices are defined as any aromatic condiment of plant origin used to alter the flavor and aroma of foods. Besides flavor and aroma, many spices have antioxidant activity, mainly related to the presence in cloves of ph...Spices are defined as any aromatic condiment of plant origin used to alter the flavor and aroma of foods. Besides flavor and aroma, many spices have antioxidant activity, mainly related to the presence in cloves of phenolic compounds, such as flavonoids, terpenoids and eugenol. In turn, the most common uses of gum arabic are in the form of powder for addition to soft drink syrups, cuisine and baked goods, specifically to stabilize the texture of products, increase the viscosity of liquids and promote the leavening of baked products (e.g., cakes). Both eugenol, extracted from cloves, and gum arabic, extracted from the hardened sap of two species of the Acacia tree, are dietary constituents routinely consumed virtually throughout the world. Both of them are also widely used medicinally to inhibit oxidative stress and genotoxicity. The prevention arm of the study included groups: Ia, IIa, IIIa, Iva, V, VI, VII, VIII. Once a week for 20 weeks, the controls received saline s.c. while the experimental groups received DMH at 20 mg/kg s.c. During the same period and for an additional 9 weeks, the animals received either water, 10% GA, EUG, or 10% GA + EUG by gavage. The treatment arm of the study included groups Ib, IIb, IIIb e IVb, IX, X, XI, XII). Once a week for 20 weeks, the controls received saline s.c. while the experimental groups received DMH at 20 mg/kg s.c. During the subsequent 9 weeks, the animals received either water, 10% GA, EUG or 10% GA + EUG by gavage. The novelty of this study is the investigation of their use alone and together for the prevention and treatment of experimental colorectal carcinogenesis induced by dimethylhydrazine. Our results show that the combined use of 10% gum arabic and eugenol was effective, with antioxidant action in the colon, as well as reducing oxidative stress in all colon segments and preventing and treating genotoxicity in all colon segments. Furthermore, their joint administration reduced the number of aberrant crypts and the number of aberrant crypt foci (ACF) in the distal segment and entire colon, as well as the number of ACF with at least 5 crypts in the entire colon. Thus, our results also demonstrate the synergistic effects of 10% gum arabic together with eugenol (from cloves), with antioxidant, antigenotoxic and anticarcinogenic actions (prevention and treatment) at the doses and durations studied, in the colon of rats submitted to colorectal carcinogenesis induced by dimethylhydrazine.展开更多
Plant extracts from natural sources are an excellent choice for food additives and natural antioxidants.In this study,the active components of Tulipa edulis were extracted and analysed,and their antioxidant capacity w...Plant extracts from natural sources are an excellent choice for food additives and natural antioxidants.In this study,the active components of Tulipa edulis were extracted and analysed,and their antioxidant capacity was measured.Then,the crude extract mixture was separated and purified using a Sephadex LH-20 gel,and the antioxidant activity of the purified products was determined.Human umbilical vein endothelial human umbilical vein endothelial cells(HUVEC)cells were treated with 35 mmol/L glucose to construct a model of oxidative stress.Then,the cells were treated with the active component to observe whether the products of T.edulis could have a good protective effect on HUVEC cells induced by glucose.Transcriptome analysis was also performed on HUVEC cells after same treatment to explore the possible mechanism of the component F2 protecting HUVEC cells from oxidative stress induced by high glucose.The results showed that component F2 obtained from T.edulis has strong antioxidant activity.Moreover,F2 can play a strong antioxidant protective role in HUVEC cells.Meanwhile,the gene expression of heme oxygenase 1(HO-1),γ-glutamyl cysteine ligase catalytic subunit(GCLC)and NAD(P)H quinone oxidoreductase-1(NQO1)in HUVEC cells was up-regulated after treated with F2.This study provides reference value for the further development and application of T.edulis and the d evelopment of functional food.展开更多
Background Heat stress has severe negative consequences on performance and health of pigs,leading to significant economic losses.The objective of this study was to investigate the effects of supplemental vitamin E and...Background Heat stress has severe negative consequences on performance and health of pigs,leading to significant economic losses.The objective of this study was to investigate the effects of supplemental vitamin E and a botanical extract in feed or drinking water on growth performance,intestinal health,and oxidative and immune status in grow-ing pigs housed under heat stress conditions.Methods Duplicate experiments were conducted,each using 64 crossbred pigs with an initial body weight of 50.7±3.8 and 43.9±3.6 kg and age of 13-week and 12-week,respectively.Pigs(n=128)were housed individually and assigned within weight blocks and sex to a 2×4 factorial arrangement consisting of 2 environments(thermo-neutral(21.2℃)or heat-stressed(30.9℃))and 4 supplementation treatments(control diet;control+100 IU/L of D-α-tocopherol in water;control+200 IU/kg of DL-α-tocopheryl-acetate in feed;or control+400 mg/kg of a botanical extract in feed).Results Heat stress for 28 d reduced(P≤0.001)final body weight,average daily gain,and average daily feed intake(-7.4 kg,-26.7%,and-25.4%,respectively)but no effects of supplementation were detected(P>0.05).Serum vitamin E increased(P<0.001)with vitamin E supplementation in water and in feed(1.64 vs.3.59 and 1.64 vs.3.24),but not for the botanical extract(1.64 vs.1.67 mg/kg)and was greater when supplemented in water vs.feed(P=0.002).Liver vitamin E increased(P<0.001)with vitamin E supplementations in water(3.9 vs.31.8)and feed(3.9 vs.18.0),but not with the botanical extract(3.9 vs.4.9 mg/kg).Serum malondialdehyde was reduced with heat stress on d 2,but increased on d 28(interaction,P<0.001),and was greater(P<0.05)for antioxidant supplementation compared to control.Cellular proliferation was reduced(P=0.037)in the jejunum under heat stress,but increased in the ileum when vitamin E was supplemented in feed and water under heat stress(interaction,P=0.04).Tumor necrosis factor-αin jejunum and ileum mucosa decreased by heat stress(P<0.05)and was reduced by vitamin E sup-plementations under heat stress(interaction,P<0.001).Conclusions The addition of the antioxidants in feed or in drinking water did not alleviate the negative impact of heat stress on feed intake and growth rate of growing pigs.展开更多
Aluminum (Al) toxicity is a considerable factor limiting crop yield and biomass in acidic soil. Tartary buckwheatgrowing in acidic soil may suffer from Al poisoning. Here, we investigated the influence of Al stress on...Aluminum (Al) toxicity is a considerable factor limiting crop yield and biomass in acidic soil. Tartary buckwheatgrowing in acidic soil may suffer from Al poisoning. Here, we investigated the influence of Al stress on the growthof tartary buckwheat seedling roots, and the alleviation of Al stress by silicon (Si), as has been demonstrated inmany crops. Under Al stress, root growth (total root length, primary root length, root tips, root surface area, androot volume) was significantly inhibited, and Al and malondialdehyde (MDA) accumulated in the root tips. At thesame time, catalase (CAT) and ascorbate peroxidase activities, polyphenols, flavonoids, and 1,1-diphenyl-2-picrylhydrazyl(DPPH) and 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) free-radical scavenging abilitywere significantly decreased. After the application of Si, root growth, Al accumulation, and oxidative damage wereimproved. Compared to Al-treated seedlings, the contents of ·O2− and MDA decreased by 29.39% and 25.22%,respectively. This was associated with Si-induced increases in peroxidase and CAT enzyme activity, flavonoidcompounds, and free-radical scavenging (DPPH and ABTS). The application of Si therefore has positive effectson Al toxicity in tartary buckwheat roots by reducing Al accumulation in the roots and maintaining oxidationhomeostasis.展开更多
Reactive oxygen species are closely related to tumor development.In recent years,reactive oxygen species has become a hot spot in tumor therapy,and many natural substances in nature contain compound components with an...Reactive oxygen species are closely related to tumor development.In recent years,reactive oxygen species has become a hot spot in tumor therapy,and many natural substances in nature contain compound components with anti-tumor effects.However,there is a lack of discussion on the synergistic anti-tumor effects of natural products in combination with chemotherapeutic drugs through reactive oxygen species.The terms“natural products”,“reactive oxygen species”,“anti-tumor”,and“chemotherapy”were used to identify the synergistic effects of natural products.We conducted a systematic literature search in PubMed and Web of Science databases for relevant research articles and reviews published in recent years.We systematically summarized the studies related to anti-tumor active ingredients in natural compounds in the field of reactive oxygen species in recent years.A total of 77 relevant literatures were included.Among them,45 literatures containing various natural products such as terpenoids,flavonoids,alkaloids,etc.exert anti-tumor effects by regulating reactive oxygen species levels,and 32 literatures regarding adjunctive role of natural products in anti-tumor therapy.In this study,we found that natural products exert anti-tumor effects by elevating reactive oxygen species levels.It provides strong theoretical support for future clinical studies.展开更多
BACKGROUND Premature ovarian insufficiency(POI)is a condition that causes secondary amenorrhea owing to ovarian hypofunction at an early stage.Early follicular depletion results in intractable infertility,thereby cons...BACKGROUND Premature ovarian insufficiency(POI)is a condition that causes secondary amenorrhea owing to ovarian hypofunction at an early stage.Early follicular depletion results in intractable infertility,thereby considerably reducing the quality of life of females.Given the continuum in weakened ovarian function,progressing from incipient ovarian failure(IOF)to transitional ovarian failure and further to POI,it is necessary to develop biomarkers for predicting POI.The oxidative stress states in IOF and POI were comprehensively evaluated via oxidative stress[diacron-reactive oxygen metabolites(d-ROMs)]test and anti-oxidant capacity[biological antioxidant potential(BAP)].METHODS Females presenting with secondary amenorrhea over 4 mo and a follicle stimulating hormone level of>40 mIU/mL were categorized into the POI group.Females presenting with a normal menstrual cycle and a follicle stimulating hormone level of>10.2 mIU/mL were categorized into the IOF group.Healthy females without ovarian hypofunction were categorized into the control group.Among females aged<40 years who visited our hospital from January 2021 to June 2022,we recruited 11 patients into both POI and IOF groups.For the potential antioxidant capacity,the relative oxidative stress index(BAP/d-ROMs×100)was calculated,and the oxidative stress defense system was comprehensively evaluated.RESULTS d-ROMs were significantly higher in the POI and IOF groups than in the control group,(478.2±58.7 U.CARR,434.5±60.6 U.CARR,and 341.1±35.1 U.CARR,respectively)(U.CARR is equivalent to 0.08 mg/dL of hydrogen peroxide).However,no significant difference was found between the POI and IOF groups.Regarding BAP,no significant difference was found between the control,IOF,and POI groups(2078.5±157.4μmol/L,2116.2±240.2μmol/L,and 2029.0±186.4μmol/L,respectively).The oxidative stress index was significantly higher in the POI and IOF groups than in the control group(23.7±3.3,20.7±3.6,and 16.5±2.1,respectively).However,no significant difference was found between the POI and IOF groups.CONCLUSION High levels of oxidative stress suggest that evaluating the oxidative stress state may be a useful indicator for the early detection of POI.展开更多
Chronic liver disease(CLD)is a continuous process that causes a reduction of liver function lasting more than six months.CLD includes alcoholic liver disease(ALD),non-alcoholic fatty liver disease(NAFLD),chronic viral...Chronic liver disease(CLD)is a continuous process that causes a reduction of liver function lasting more than six months.CLD includes alcoholic liver disease(ALD),non-alcoholic fatty liver disease(NAFLD),chronic viral infection,and autoimmune hepatitis,which can lead to liver fibrosis,cirrhosis,and cancer.Liver inflammation and oxidative stress are commonly associated with the development and progression of CLD.Molecular signaling pathways such as AMPactivated protein kinase(AMPK),C-Jun N-terminal kinase,and peroxisome proliferator-activated receptors(PPARs)are implicated in the pathogenesis of CLD.Therefore,antioxidant and anti-inflammatory agents from natural products are new potent therapies for ALD,NAFLD,and hepatocellular carcinoma(HCC).In this review,we summarize some powerful products that can be potential applied in all the stages of CLD,from ALD/NAFLD to HCC.The selected agents such asβ-sitosterol,curcumin,genistein,and silymarin can regulate the activation of several important molecules,including AMPK,Farnesoid X receptor,nuclear factor erythroid 2-related factor-2,PPARs,phosphatidylinositol-3-kinase,and lysyl oxidase-like proteins.In addition,clinical trials are undergoing to evaluate their efficacy and safety.展开更多
Objective A strain of Aspergillus niger(A. niger), capable of releasing bound phenolic acids from wheat bran, was isolated. This strain was identified by gene sequence identification. The antioxidant and anti-inflamma...Objective A strain of Aspergillus niger(A. niger), capable of releasing bound phenolic acids from wheat bran, was isolated. This strain was identified by gene sequence identification. The antioxidant and anti-inflammatory capacity of ferulic acid released from wheat bran by this A. niger strain(FA-WB) were evaluated. Methods Molecular identification techniques based on PCR analysis of specific genomic sequences were conducted; antioxidant ability was examined using oxygen radical absorbance capacity(ORAC), cellular antioxidant activity(CAA) assays, and erythrocyte hemolysis assays. RAW264.7 cells were used as a model to detect anti-inflammatory activity. Results The filamentous fungal isolate was identified to be A. niger. ORAC and CAA assay showed that FA-WB had better antioxidant activity than that of the ferulic acid standard. The erythrocyte hemolysis assay results suggested that FA-WB could attenuate AAPH-induced oxidative stress through inhibition of reactive oxy gen species(ROS) generation. FA-WB could significantly restore the AAPH-induced increase in intracellular antioxidant enzyme activities to normal levels as well as inhibit the intracellular malondialdehyde formation. TNF-?, IL-6, and NO levels indicated that FA-WB can inhibit the inflammation induced by lipopolysaccharide(LPS). Conclusion Ferulic acid released from wheat bran by a new strain of A. niger had good anti-inflammatory activity and better antioxidant ability than standard ferulic acid.展开更多
A high thrust-to-weight ratio poses challenges to the high-temperature performance of Ni-based superalloys. The oxidation behavior of GH4738 at extreme temperatures has been investigated by isothermal and non-isotherm...A high thrust-to-weight ratio poses challenges to the high-temperature performance of Ni-based superalloys. The oxidation behavior of GH4738 at extreme temperatures has been investigated by isothermal and non-isothermal experiments. As a result of the competitive diffusion of alloying elements, the oxide scale included an outermost porous oxide layer (OOL), an inner relatively dense oxide layer (IOL), and an internal oxide zone (IOZ), depending on the temperature and time. A high temperature led to the formation of large voids at the IOL/IOZ interface. At 1200℃, the continuity of the Cr-rich oxide layer in the IOL was destroyed, and thus, spallation occurred. Extension of oxidation time contributed to the size of Al-rich oxide particles with the increase in the IOZ. Based on this finding,the oxidation kinetics of GH4738 was discussed, and the corresponding oxidation behavior at 900-1100℃ was predicted.展开更多
Our previous studies revealed that etomidate, a non-barbiturate intravenous anesthetic agent, has protective effects on retinal ganglion cells within 7 days after optic nerve transection. Whether this process is relat...Our previous studies revealed that etomidate, a non-barbiturate intravenous anesthetic agent, has protective effects on retinal ganglion cells within 7 days after optic nerve transection. Whether this process is related to anti-oxidative stress is not clear. To reveal its mechanism, we established the optic nerve transection injury model by transecting 1 mm behind the left eyeball of adult male Sprague-Dawley rats. The rats received an intraperitoneal injection of etomidate(4 mg/kg) once per day for 7 days. The results showed that etomidate significantly enhanced the number of retinal ganglion cells retrogradely labeled with Fluorogold at 7 days after optic nerve transection. Etomidate also significantly reduced the levels of nitric oxide and malonaldehyde in the retina and increased the level of glutathione at 12 hours after optic nerve transection. Thus, etomidate can protect retinal ganglion cells after optic nerve transection in adult rats by activating an anti-oxidative stress response. The study was approved by the Animal Ethics Committee at Air Force Medical University, China(approval No. 20180305) on March 5, 2018.展开更多
Picroside II,the major active component of picroside,has been shown to induce PC12 cell axonal growth and relieve free radical damage.In vivo experiments have demonstrated that picroside II can improve neurological fu...Picroside II,the major active component of picroside,has been shown to induce PC12 cell axonal growth and relieve free radical damage.In vivo experiments have demonstrated that picroside II can improve neurological function in rats with cerebral ischemia/reperfusion injuries.In the present in vivo study,enzyme-linked immunosorbent assay and immunohistochemistry revealed that picroside II increased superoxide dismutase content and reduced inducible nitric oxide synthase content in the ischemic hemisphere.The effects of picroside II were similar to those of salvianic acid A sodium,an active control drug.These results indicate that picroside II exerts a neuroprotective effect,possibly by downregulating inducible nitric oxide synthase expression,increasing superoxide dismutase activity,and inhibiting neuronal apoptosis.展开更多
With graphite currently leading as the most viable anode for potassium-ion batteries(KIBs),other materials have been left relatively underexamined.Transition metal oxides are among these,with many positive attributes ...With graphite currently leading as the most viable anode for potassium-ion batteries(KIBs),other materials have been left relatively underexamined.Transition metal oxides are among these,with many positive attributes such as synthetic maturity,longterm cycling stability and fast redox kinetics.Therefore,to address this research deficiency we report herein a layered potassium titanium niobate KTiNbO5(KTNO)and its rGO nanocomposite(KTNO/rGO)synthesised via solvothermal methods as a high-performance anode for KIBs.Through effective distribution across the electrically conductive rGO,the electrochemical performance of the KTNO nanoparticles was enhanced.The potassium storage performance of the KTNO/rGO was demonstrated by its first charge capacity of 128.1 mAh g^(−1) and reversible capacity of 97.5 mAh g^(−1) after 500 cycles at 20 mA g^(−1),retaining 76.1%of the initial capacity,with an exceptional rate performance of 54.2 mAh g^(−1)at 1 A g^(−1).Furthermore,to investigate the attributes of KTNO in-situ XRD was performed,indicating a low-strain material.Ex-situ X-ray photoelectron spectra further investigated the mechanism of charge storage,with the titanium showing greater redox reversibility than the niobium.This work suggests this lowstrain nature is a highly advantageous property and well worth regarding KTNO as a promising anode for future high-performance KIBs.展开更多
In order to better understand the specific substituent effects on the electrochemical oxidation process of β-O-4 bond, a series of methoxyphenyl type β-O-4 dimer model compounds with different localized methoxyl gro...In order to better understand the specific substituent effects on the electrochemical oxidation process of β-O-4 bond, a series of methoxyphenyl type β-O-4 dimer model compounds with different localized methoxyl groups, including 2-(2-methoxyphenoxy)-1-phenylethanone, 2-(2-methoxyphenoxy)-1-phenylethanol, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanol, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanol have been selected and their electrochemical properties have been studied experimentally by cyclic voltammetry, and FT-IR spectroelectrochemistry. Combining with electrolysis products distribution analysis and density functional theory calculations, oxidation mechanisms of all six model dimers have been explored. In particular, a total effect from substituents of both para-methoxy(on the aryl ring closing to Cα) and Cα-OH on the oxidation mechanisms has been clearly observed, showing a significant selectivity on the Cα-Cβbond cleavage induced by electrochemical oxidations.展开更多
It is known that the pathogenicity of Plasmodium induces the breakdown of haemoglobin, which leads to the induction of oxidative stress. This study aimed to identify the possible effects of oxidative stress and antiox...It is known that the pathogenicity of Plasmodium induces the breakdown of haemoglobin, which leads to the induction of oxidative stress. This study aimed to identify the possible effects of oxidative stress and antioxidant defence systems in symptomatic and asymptomatic Plasmodium falciparum malaria infection in children (1 - 15 years old) in the Mount Cameroon vicinity. This cross-sectional study involved blood samples collected from 473 children and examined for malaria parasitaemia. Full blood counts were performed using an automated haemoanalyser. Serum oxidative stress status (malondialdehyde (MDA), nitric oxide (NO), reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD) and vitamin C (Vit C)) were each determined by colorimetric enzymatic assays. The prevalence of malaria parasite infection was 32.1% among the participants. Out of that, 62.5% of patients with parasitaemia were symptomatic. Anaemia prevalence increased significantly with parasite density. MDA levels were significantly higher in patients with malaria symptoms than in those without symptoms. A significant and positive correlation was detected between MDA (r = 0.831, P < 0.05), NO (r = 0.779, P < 0.05), and malaria parasite density while, a significant and negative relationship occurred between parasite density and GSH (r = ?0.763, P < 0.05) and Vit C (r = ?0.826, P < 0.05) levels, SOD (r = ?0.621, P < 0.05) and CAT (r = ?0.817, P < 0.05) activities. The SOD activity and GSH level significantly decreased (P < 0.05) with an increase in the MDA levels. These findings showed that MDA and nitric oxide levels increased both in malaria participants with or without symptoms. A similar decrease in the antioxidant defence system was observed in both symptomatic and asymptomatic patients. Therefore, there is a need to develop public health policies that encourage routine diagnosis and treatment of malaria in seemingly healthy people (asymptomatic cases), and this will play an essential role in controlling malaria in tropical countries.展开更多
Objective:To investigate the inflammatory and antioxidant activities of ethanolie extract of aerial part of Vernonia patula(Dryand.)Merr(EAV).Methods:The anti-inflammatory activity of EAV was studied using carrageenan...Objective:To investigate the inflammatory and antioxidant activities of ethanolie extract of aerial part of Vernonia patula(Dryand.)Merr(EAV).Methods:The anti-inflammatory activity of EAV was studied using carrageenan and histamine-induced rat paw edema test at different doses(100.200 and 400 mg/kg body weight).DPPH free radical scavenging,nitric oxide scavenging,reducing power and Fe^(2+)ion chelating ability were used for determining antioxidant activities.Results:The EAV,at the dose of 400 mg/kg,showed a significant anti-inflammatory activity(P<0.01)both in the carrageenan and histamine-induced oedema test models in rats,showing62.86%and 64.42%reduction in the paw volume comparable to that produced by the standard drug indomethacin(67.26%and 66.01%)at 5 h respectively.In DPPH free radical scavenging test,IC_(50)value for EAV was found fairly significant 36.59μg/mL when compared to the IC_(50)value of the reference standards ascorbic acid 8.97μg/mL.The IC_(50)values of the extract and ascorbic acid were 47.72 and 12.39μg/mL,respectively in nitric oxide scavenging assay.The IC_(50)value of the EAV(33.59μg/mL)as percentage of Fe^(2+)ion chelating ability was also found significant compared to that of EDTA(9.16μg/mL).The maximum absorbance for reducing power assay was found to be1.928 at 100μg/mL when compared to 2.449 for standard ascorbic acid.The total phenolic content was 198.81 mg/g of gallic acid equivalent.Acute toxicity test showed that the plant might be safe for pharmacological uses up to a dose level of 3200 mg/kg of body weight in rats.Conclusions:Therefore,the obtained results suggest the acute anti-inflammatory and antioxidant activities of the EAV and thus provide the scientific basis for the traditional uses of this plant part as a remedy for inflammations.展开更多
Objective: To determine the bioactive compounds of Orostachys japonicus(O. japonicus)(Maxim.) A. Berger extraction by different solvents(70% ethanol or water) and to evaluate the in vitro antioxidant and anti-inflamma...Objective: To determine the bioactive compounds of Orostachys japonicus(O. japonicus)(Maxim.) A. Berger extraction by different solvents(70% ethanol or water) and to evaluate the in vitro antioxidant and anti-inflammatory activities. Methods: Total polyphenol, flavonoid, and anthocyanin contents in O. japonicus extract were measured. Antioxidant activities were determined by DPPH, ABTS, and superoxide radical-scavenging ability assays. Anti-inflammatory activities were evaluated by nitric oxide production, tumor necrosis factor-α, and interleukin-6 expression techniques. Results: Extraction with 70% ethanol yielded the highest total polyphenol(60.03 mg/g dry weight) and flavonoid(55.50 mg/g dry weight) contents. The total anthocyanin contents in 70% ethanol and water extracts were 57.25 and 91.71 mg/g dry weight, respectively. The 70% ethanol extract also showed stronger antioxidant activity than the water extract. Antioxidant activity and reducing power increased with the increasing concentration of O. japonicus extract. O. japonicus extract at 0-400 μg/m L did not affect the growth of RAW 264.7 cells, whereas dose-dependent inhibition of nitric oxide, tumor necrosis factor-α, and interleukin-6 production was observed.Conclusions: O. japonicus inhibits oxidative and inflammatory reactions with potentially positive health-related effects.展开更多
Because of their high efficiency, antibiotics have long been the primary treatment for infections, but the rise of drug-resistant pathogens has become a therapeutic concern. Nanoparticles, as novel biomaterials, are c...Because of their high efficiency, antibiotics have long been the primary treatment for infections, but the rise of drug-resistant pathogens has become a therapeutic concern. Nanoparticles, as novel biomaterials, are currently gaining global attention to combat them. Drug-resistant diseases may need the use of nanoparticles as a viable therapeutic option. By altering target locations and enzymes, decreasing cell permeability, inactivating enzymes, and increasing efflux by overexpressing efflux pumps, they can bypass conventional resistance mechanisms. Therefore, understanding how metal and metal oxide nanoparticles affect microorganisms that are resistant to antimicrobial drugs is the main objective of this review. Accordingly, the uses of metal and metal oxide nanoparticles in the fight against drug-resistant diseases appear promising. However, their mechanism of action, dose, and possible long-term effects require special attention and future research. Furthermore, repeated use of silver nanoparticles may cause gram-negative microorganisms to acquire resistance, necessitating additional study.展开更多
Objective: To determine the cytotoxicity, reduction in nitric oxide production and antioxidative activity of the aqueous leaf extract from Tithonia diversifolia(T. diversifolia) in an in vitro model.Methods: Leaves of...Objective: To determine the cytotoxicity, reduction in nitric oxide production and antioxidative activity of the aqueous leaf extract from Tithonia diversifolia(T. diversifolia) in an in vitro model.Methods: Leaves of T. diversifolia were collected from natural habitats and extracted with distilled water using the decoction method. The cytotoxic effect of the extract in terms of cell viability was determined using RAW264.7 cells and human peripheral blood mononuclear cells(PBMCs) via the mitochondrial respiration method using the MTT reagent. The effect of the extract on lipopolysaccharide(LPS)-induced nitric oxide production in RAW264.7 cells was measured using the Griess reagent. The chemical antioxidant was evaluated by ABTS- and DPPH-radical scavenging assays.Results: The half-maximal cytotoxic concentration values were 145.87 mg/m L and73.67 mg/m L for human PBMCs and RAW264.7 cells, respectively. In the presence of phytohemagglutinin-M, the IC_(50) on PBMCs proliferation was 4.42 mg/m L. The noncytotoxic range of the extracts inhibited LPS-induced nitrite production in RAW264.7 cells with an IC_(50) value of 11.63 mg/m L. To determine the anti-oxidative properties, the N-acetyl cysteine equivalent antioxidant capacity of the extract was(32.62 ± 1.87) and(20.99 ± 2.79)mg N-acetyl cysteine/g extract, respectively determined by the ABTS-radical and DPPHradical assay. However, the extract did not confer death protection in a hydrogen peroxideinduced RAW264.7 co-culturing model.Conclusions: Our study demonstrated the immunomodulation caused by the aqueous leaf extract of T. diversifolia, resulting from the inhibition of phytohemagglutinin-Minduced PBMCs proliferation and LPS-induced nitric oxide production in RAW264.7macrophages. Although the anti-oxidative activity was presented in the chemical-based anti-oxidant assay, the extract cannot protect cell death from stress conditions.展开更多
Chrysanthellum americanum (L.) Vatke is a medicinal plant used by the traditional healers to treat epilepsy and associated memory impairment. This work aims at evaluating the anticonvulsant effects of Chrysanthellum a...Chrysanthellum americanum (L.) Vatke is a medicinal plant used by the traditional healers to treat epilepsy and associated memory impairment. This work aims at evaluating the anticonvulsant effects of Chrysanthellum americanum aqueous extract in mice pilocarpine model of epilepsy and associated memory loss. Mice were administered orally Chrysanthellum americanum aqueous extract (27.69, 69.22, 138.45, 276.9 mg/kg, prepared from the whole part) for test groups, intraperitoneally 300 mg/kg sodium valproate for the positive control group or orally 10 mL/kg distilled water for the negative control group, respectively, during a period of seven consecutive days. On the first day, temporal lobe epilepsy was induced by intraperitoneal injection of 360 mg/kg pilocarpine one hour after the administration of different treatment to mice, and the occurrence of status epilepticus was evaluated. On the second day, the anticonvulsant property was measured after the intraperitoneal injection of a sub-convulsive dose of picrotoxin (1 mg/kg). On the seventh day, the anti-amnesic properties of the extract were evaluated in the epileptic mice using the T-maze and open field paradigms. The results show that Chrysanthellum americanum extract significantly (p Chrysanthellum americanum (276.9 mg/kg) likewise sodium valproate (300 mg/kg) significantly (p Chrysanthellum americanum aqueous extract has anticonvulsant effects against pilocarpine induced-epileptic seizures and memory impairment. These properties could be mediated by the amelioration of antioxidant defense system and cholinergic neurotransmission in epileptic mice, which could partly justify the use of Chrysanthellum americanum in the traditional medicine for the treatment of epilepsy.展开更多
The Mn-based oxide cathode with enriched crystal phase structure and component diversity can provide the excellent chemistry structure for Na-ion batteries.Nevertheless,the broad application prospect is obstructed by ...The Mn-based oxide cathode with enriched crystal phase structure and component diversity can provide the excellent chemistry structure for Na-ion batteries.Nevertheless,the broad application prospect is obstructed by the sluggish Na^(+)kinetics and the phase transitions upon cycling.Herein,we establish the thermodynamically stable phase diagram of various Mn-based oxide composites precisely controlled by sodium content tailoring strategy coupling with co-doping and solid-state reaction.The chemical environment of the P2/P'3 and P2/P3 biphasic composites indicate that the charge compensation mechanism stems from the cooperative contribution of anions and cations.Benefiting from the no phase transition to scavenge the structure strain,P2/P'3 electrode can deliver long cycling stability(capacity retention of 73.8%after 1000 cycles at 10 C)and outstanding rate properties(the discharge capacity of 84.08 mA h g^(-1)at 20 C)than P2/P3 electrode.Furthermore,the DFT calculation demonstrates that the introducing novel P'3 phase can significantly regulate the Na^(+)reaction dynamics and modify the local electron configuration of Mn.The effective phase engineering can provide a reference for designing other high-performance electrode materials for Na-ion batteries.展开更多
文摘Spices are defined as any aromatic condiment of plant origin used to alter the flavor and aroma of foods. Besides flavor and aroma, many spices have antioxidant activity, mainly related to the presence in cloves of phenolic compounds, such as flavonoids, terpenoids and eugenol. In turn, the most common uses of gum arabic are in the form of powder for addition to soft drink syrups, cuisine and baked goods, specifically to stabilize the texture of products, increase the viscosity of liquids and promote the leavening of baked products (e.g., cakes). Both eugenol, extracted from cloves, and gum arabic, extracted from the hardened sap of two species of the Acacia tree, are dietary constituents routinely consumed virtually throughout the world. Both of them are also widely used medicinally to inhibit oxidative stress and genotoxicity. The prevention arm of the study included groups: Ia, IIa, IIIa, Iva, V, VI, VII, VIII. Once a week for 20 weeks, the controls received saline s.c. while the experimental groups received DMH at 20 mg/kg s.c. During the same period and for an additional 9 weeks, the animals received either water, 10% GA, EUG, or 10% GA + EUG by gavage. The treatment arm of the study included groups Ib, IIb, IIIb e IVb, IX, X, XI, XII). Once a week for 20 weeks, the controls received saline s.c. while the experimental groups received DMH at 20 mg/kg s.c. During the subsequent 9 weeks, the animals received either water, 10% GA, EUG or 10% GA + EUG by gavage. The novelty of this study is the investigation of their use alone and together for the prevention and treatment of experimental colorectal carcinogenesis induced by dimethylhydrazine. Our results show that the combined use of 10% gum arabic and eugenol was effective, with antioxidant action in the colon, as well as reducing oxidative stress in all colon segments and preventing and treating genotoxicity in all colon segments. Furthermore, their joint administration reduced the number of aberrant crypts and the number of aberrant crypt foci (ACF) in the distal segment and entire colon, as well as the number of ACF with at least 5 crypts in the entire colon. Thus, our results also demonstrate the synergistic effects of 10% gum arabic together with eugenol (from cloves), with antioxidant, antigenotoxic and anticarcinogenic actions (prevention and treatment) at the doses and durations studied, in the colon of rats submitted to colorectal carcinogenesis induced by dimethylhydrazine.
基金supported by the Open Grant of Beijing Advanced Innovation Center for Food Nutrition and Human Health(20182024)National Natural Science Foundation of China(31370104)+4 种基金The Natural Science Foundation of Hunan Province,China(2021JJ30029)the Taishan Scholar Program of Shandong Province,China(tsqn201909168)“Double Hundred”Program for Foreign Experts of Shandong Province,China(WST2017004)Hunan Province Postgraduate Education Innovation Project and Professional Capacity Enhancement(CX20200297)Project the Fundamental Research Funds for the Central Universities of Central South University(2020zzts424,2020zzts422)。
文摘Plant extracts from natural sources are an excellent choice for food additives and natural antioxidants.In this study,the active components of Tulipa edulis were extracted and analysed,and their antioxidant capacity was measured.Then,the crude extract mixture was separated and purified using a Sephadex LH-20 gel,and the antioxidant activity of the purified products was determined.Human umbilical vein endothelial human umbilical vein endothelial cells(HUVEC)cells were treated with 35 mmol/L glucose to construct a model of oxidative stress.Then,the cells were treated with the active component to observe whether the products of T.edulis could have a good protective effect on HUVEC cells induced by glucose.Transcriptome analysis was also performed on HUVEC cells after same treatment to explore the possible mechanism of the component F2 protecting HUVEC cells from oxidative stress induced by high glucose.The results showed that component F2 obtained from T.edulis has strong antioxidant activity.Moreover,F2 can play a strong antioxidant protective role in HUVEC cells.Meanwhile,the gene expression of heme oxygenase 1(HO-1),γ-glutamyl cysteine ligase catalytic subunit(GCLC)and NAD(P)H quinone oxidoreductase-1(NQO1)in HUVEC cells was up-regulated after treated with F2.This study provides reference value for the further development and application of T.edulis and the d evelopment of functional food.
基金YVSG was funded by a doctoral scholarship provided by the Peruvian National Fund,for Scientific,Technological,and Technological Innovation Development(FONDECYT)the funding branch of the National Council for Science,Technological,and Technological Innovation Development(CONCYTEC),Peru(grant contract No 233-2015-FONDECYT).
文摘Background Heat stress has severe negative consequences on performance and health of pigs,leading to significant economic losses.The objective of this study was to investigate the effects of supplemental vitamin E and a botanical extract in feed or drinking water on growth performance,intestinal health,and oxidative and immune status in grow-ing pigs housed under heat stress conditions.Methods Duplicate experiments were conducted,each using 64 crossbred pigs with an initial body weight of 50.7±3.8 and 43.9±3.6 kg and age of 13-week and 12-week,respectively.Pigs(n=128)were housed individually and assigned within weight blocks and sex to a 2×4 factorial arrangement consisting of 2 environments(thermo-neutral(21.2℃)or heat-stressed(30.9℃))and 4 supplementation treatments(control diet;control+100 IU/L of D-α-tocopherol in water;control+200 IU/kg of DL-α-tocopheryl-acetate in feed;or control+400 mg/kg of a botanical extract in feed).Results Heat stress for 28 d reduced(P≤0.001)final body weight,average daily gain,and average daily feed intake(-7.4 kg,-26.7%,and-25.4%,respectively)but no effects of supplementation were detected(P>0.05).Serum vitamin E increased(P<0.001)with vitamin E supplementation in water and in feed(1.64 vs.3.59 and 1.64 vs.3.24),but not for the botanical extract(1.64 vs.1.67 mg/kg)and was greater when supplemented in water vs.feed(P=0.002).Liver vitamin E increased(P<0.001)with vitamin E supplementations in water(3.9 vs.31.8)and feed(3.9 vs.18.0),but not with the botanical extract(3.9 vs.4.9 mg/kg).Serum malondialdehyde was reduced with heat stress on d 2,but increased on d 28(interaction,P<0.001),and was greater(P<0.05)for antioxidant supplementation compared to control.Cellular proliferation was reduced(P=0.037)in the jejunum under heat stress,but increased in the ileum when vitamin E was supplemented in feed and water under heat stress(interaction,P=0.04).Tumor necrosis factor-αin jejunum and ileum mucosa decreased by heat stress(P<0.05)and was reduced by vitamin E sup-plementations under heat stress(interaction,P<0.001).Conclusions The addition of the antioxidants in feed or in drinking water did not alleviate the negative impact of heat stress on feed intake and growth rate of growing pigs.
基金Science&Technology Department of Sichuan Province(2022YFQ0041,2022NSFSC1725,2023NSFSC0214)China Agriculture Research System(CARS-07-B-1)+2 种基金The National Natural Science Foundation of China(32160428)Innovative Training Program for College Students(202311079040,S202311079112,CDUCX2023550)Undergraduate Education and Teaching Reform Project of Chengdu University(cdjgb2022186).
文摘Aluminum (Al) toxicity is a considerable factor limiting crop yield and biomass in acidic soil. Tartary buckwheatgrowing in acidic soil may suffer from Al poisoning. Here, we investigated the influence of Al stress on the growthof tartary buckwheat seedling roots, and the alleviation of Al stress by silicon (Si), as has been demonstrated inmany crops. Under Al stress, root growth (total root length, primary root length, root tips, root surface area, androot volume) was significantly inhibited, and Al and malondialdehyde (MDA) accumulated in the root tips. At thesame time, catalase (CAT) and ascorbate peroxidase activities, polyphenols, flavonoids, and 1,1-diphenyl-2-picrylhydrazyl(DPPH) and 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) free-radical scavenging abilitywere significantly decreased. After the application of Si, root growth, Al accumulation, and oxidative damage wereimproved. Compared to Al-treated seedlings, the contents of ·O2− and MDA decreased by 29.39% and 25.22%,respectively. This was associated with Si-induced increases in peroxidase and CAT enzyme activity, flavonoidcompounds, and free-radical scavenging (DPPH and ABTS). The application of Si therefore has positive effectson Al toxicity in tartary buckwheat roots by reducing Al accumulation in the roots and maintaining oxidationhomeostasis.
基金supported by National Natural Science Foundation of China(No.82003775)Talent Project established by Chinese Pharmaceutical Association Hospital Phamacy department.(No.CPA-Z05-ZC-2023-003)+2 种基金Outstanding Young Scholars Foundation of Harbin Medical University Cancer Hospital(No.JCQN2021-04)Heilongjiang Province postdoctoral research fund(No.LBH-Q20050)Special fund for clinical and basic research of medical research development fund(No.YXKY-WS013G).
文摘Reactive oxygen species are closely related to tumor development.In recent years,reactive oxygen species has become a hot spot in tumor therapy,and many natural substances in nature contain compound components with anti-tumor effects.However,there is a lack of discussion on the synergistic anti-tumor effects of natural products in combination with chemotherapeutic drugs through reactive oxygen species.The terms“natural products”,“reactive oxygen species”,“anti-tumor”,and“chemotherapy”were used to identify the synergistic effects of natural products.We conducted a systematic literature search in PubMed and Web of Science databases for relevant research articles and reviews published in recent years.We systematically summarized the studies related to anti-tumor active ingredients in natural compounds in the field of reactive oxygen species in recent years.A total of 77 relevant literatures were included.Among them,45 literatures containing various natural products such as terpenoids,flavonoids,alkaloids,etc.exert anti-tumor effects by regulating reactive oxygen species levels,and 32 literatures regarding adjunctive role of natural products in anti-tumor therapy.In this study,we found that natural products exert anti-tumor effects by elevating reactive oxygen species levels.It provides strong theoretical support for future clinical studies.
文摘BACKGROUND Premature ovarian insufficiency(POI)is a condition that causes secondary amenorrhea owing to ovarian hypofunction at an early stage.Early follicular depletion results in intractable infertility,thereby considerably reducing the quality of life of females.Given the continuum in weakened ovarian function,progressing from incipient ovarian failure(IOF)to transitional ovarian failure and further to POI,it is necessary to develop biomarkers for predicting POI.The oxidative stress states in IOF and POI were comprehensively evaluated via oxidative stress[diacron-reactive oxygen metabolites(d-ROMs)]test and anti-oxidant capacity[biological antioxidant potential(BAP)].METHODS Females presenting with secondary amenorrhea over 4 mo and a follicle stimulating hormone level of>40 mIU/mL were categorized into the POI group.Females presenting with a normal menstrual cycle and a follicle stimulating hormone level of>10.2 mIU/mL were categorized into the IOF group.Healthy females without ovarian hypofunction were categorized into the control group.Among females aged<40 years who visited our hospital from January 2021 to June 2022,we recruited 11 patients into both POI and IOF groups.For the potential antioxidant capacity,the relative oxidative stress index(BAP/d-ROMs×100)was calculated,and the oxidative stress defense system was comprehensively evaluated.RESULTS d-ROMs were significantly higher in the POI and IOF groups than in the control group,(478.2±58.7 U.CARR,434.5±60.6 U.CARR,and 341.1±35.1 U.CARR,respectively)(U.CARR is equivalent to 0.08 mg/dL of hydrogen peroxide).However,no significant difference was found between the POI and IOF groups.Regarding BAP,no significant difference was found between the control,IOF,and POI groups(2078.5±157.4μmol/L,2116.2±240.2μmol/L,and 2029.0±186.4μmol/L,respectively).The oxidative stress index was significantly higher in the POI and IOF groups than in the control group(23.7±3.3,20.7±3.6,and 16.5±2.1,respectively).However,no significant difference was found between the POI and IOF groups.CONCLUSION High levels of oxidative stress suggest that evaluating the oxidative stress state may be a useful indicator for the early detection of POI.
文摘Chronic liver disease(CLD)is a continuous process that causes a reduction of liver function lasting more than six months.CLD includes alcoholic liver disease(ALD),non-alcoholic fatty liver disease(NAFLD),chronic viral infection,and autoimmune hepatitis,which can lead to liver fibrosis,cirrhosis,and cancer.Liver inflammation and oxidative stress are commonly associated with the development and progression of CLD.Molecular signaling pathways such as AMPactivated protein kinase(AMPK),C-Jun N-terminal kinase,and peroxisome proliferator-activated receptors(PPARs)are implicated in the pathogenesis of CLD.Therefore,antioxidant and anti-inflammatory agents from natural products are new potent therapies for ALD,NAFLD,and hepatocellular carcinoma(HCC).In this review,we summarize some powerful products that can be potential applied in all the stages of CLD,from ALD/NAFLD to HCC.The selected agents such asβ-sitosterol,curcumin,genistein,and silymarin can regulate the activation of several important molecules,including AMPK,Farnesoid X receptor,nuclear factor erythroid 2-related factor-2,PPARs,phosphatidylinositol-3-kinase,and lysyl oxidase-like proteins.In addition,clinical trials are undergoing to evaluate their efficacy and safety.
基金financially supported by the Science and Technology Planning Project of Guangdong Province [Nos.2016A040402020,2016B010121014]
文摘Objective A strain of Aspergillus niger(A. niger), capable of releasing bound phenolic acids from wheat bran, was isolated. This strain was identified by gene sequence identification. The antioxidant and anti-inflammatory capacity of ferulic acid released from wheat bran by this A. niger strain(FA-WB) were evaluated. Methods Molecular identification techniques based on PCR analysis of specific genomic sequences were conducted; antioxidant ability was examined using oxygen radical absorbance capacity(ORAC), cellular antioxidant activity(CAA) assays, and erythrocyte hemolysis assays. RAW264.7 cells were used as a model to detect anti-inflammatory activity. Results The filamentous fungal isolate was identified to be A. niger. ORAC and CAA assay showed that FA-WB had better antioxidant activity than that of the ferulic acid standard. The erythrocyte hemolysis assay results suggested that FA-WB could attenuate AAPH-induced oxidative stress through inhibition of reactive oxy gen species(ROS) generation. FA-WB could significantly restore the AAPH-induced increase in intracellular antioxidant enzyme activities to normal levels as well as inhibit the intracellular malondialdehyde formation. TNF-?, IL-6, and NO levels indicated that FA-WB can inhibit the inflammation induced by lipopolysaccharide(LPS). Conclusion Ferulic acid released from wheat bran by a new strain of A. niger had good anti-inflammatory activity and better antioxidant ability than standard ferulic acid.
基金financially supported by the National Key R&D Program of China (No.2021YFB3700400)the National Natural Science Foundation of China (Nos.52074030,51904021,and 52174294)。
文摘A high thrust-to-weight ratio poses challenges to the high-temperature performance of Ni-based superalloys. The oxidation behavior of GH4738 at extreme temperatures has been investigated by isothermal and non-isothermal experiments. As a result of the competitive diffusion of alloying elements, the oxide scale included an outermost porous oxide layer (OOL), an inner relatively dense oxide layer (IOL), and an internal oxide zone (IOZ), depending on the temperature and time. A high temperature led to the formation of large voids at the IOL/IOZ interface. At 1200℃, the continuity of the Cr-rich oxide layer in the IOL was destroyed, and thus, spallation occurred. Extension of oxidation time contributed to the size of Al-rich oxide particles with the increase in the IOZ. Based on this finding,the oxidation kinetics of GH4738 was discussed, and the corresponding oxidation behavior at 900-1100℃ was predicted.
基金supported by the National Natural Science Foundation of China,No.81670846(to MMW)and 81470631(to SWY)the Natural Science Foundation of Shaanxi Province of China,No.2016SF-171(to MMW)the National Basic Research Program of China,No.2014CB542202(to SWY)
文摘Our previous studies revealed that etomidate, a non-barbiturate intravenous anesthetic agent, has protective effects on retinal ganglion cells within 7 days after optic nerve transection. Whether this process is related to anti-oxidative stress is not clear. To reveal its mechanism, we established the optic nerve transection injury model by transecting 1 mm behind the left eyeball of adult male Sprague-Dawley rats. The rats received an intraperitoneal injection of etomidate(4 mg/kg) once per day for 7 days. The results showed that etomidate significantly enhanced the number of retinal ganglion cells retrogradely labeled with Fluorogold at 7 days after optic nerve transection. Etomidate also significantly reduced the levels of nitric oxide and malonaldehyde in the retina and increased the level of glutathione at 12 hours after optic nerve transection. Thus, etomidate can protect retinal ganglion cells after optic nerve transection in adult rats by activating an anti-oxidative stress response. The study was approved by the Animal Ethics Committee at Air Force Medical University, China(approval No. 20180305) on March 5, 2018.
基金the National Natural Science Foundation of China, No. 30873391, 81041092
文摘Picroside II,the major active component of picroside,has been shown to induce PC12 cell axonal growth and relieve free radical damage.In vivo experiments have demonstrated that picroside II can improve neurological function in rats with cerebral ischemia/reperfusion injuries.In the present in vivo study,enzyme-linked immunosorbent assay and immunohistochemistry revealed that picroside II increased superoxide dismutase content and reduced inducible nitric oxide synthase content in the ischemic hemisphere.The effects of picroside II were similar to those of salvianic acid A sodium,an active control drug.These results indicate that picroside II exerts a neuroprotective effect,possibly by downregulating inducible nitric oxide synthase expression,increasing superoxide dismutase activity,and inhibiting neuronal apoptosis.
基金Y.X.acknowledges the financial support of the Engineering and Physical Sciences Research Council(EP/X000087/1,EP/V000152/1)Leverhulme Trust(RPG-2021-138)Royal Society(IEC\NSFC\223016).
文摘With graphite currently leading as the most viable anode for potassium-ion batteries(KIBs),other materials have been left relatively underexamined.Transition metal oxides are among these,with many positive attributes such as synthetic maturity,longterm cycling stability and fast redox kinetics.Therefore,to address this research deficiency we report herein a layered potassium titanium niobate KTiNbO5(KTNO)and its rGO nanocomposite(KTNO/rGO)synthesised via solvothermal methods as a high-performance anode for KIBs.Through effective distribution across the electrically conductive rGO,the electrochemical performance of the KTNO nanoparticles was enhanced.The potassium storage performance of the KTNO/rGO was demonstrated by its first charge capacity of 128.1 mAh g^(−1) and reversible capacity of 97.5 mAh g^(−1) after 500 cycles at 20 mA g^(−1),retaining 76.1%of the initial capacity,with an exceptional rate performance of 54.2 mAh g^(−1)at 1 A g^(−1).Furthermore,to investigate the attributes of KTNO in-situ XRD was performed,indicating a low-strain material.Ex-situ X-ray photoelectron spectra further investigated the mechanism of charge storage,with the titanium showing greater redox reversibility than the niobium.This work suggests this lowstrain nature is a highly advantageous property and well worth regarding KTNO as a promising anode for future high-performance KIBs.
基金The authors gratefully acknowledge the financial support of the Natural Science Foundation of China,China(Grant No.21975082 and 21736003)the Guangdong Basic and Applied Basic Research Foundation(Grant Number:2019A1515011472 and 2022A1515011341)the Science and Technology Program of Guangzhou(Grant Number:202102080479).
文摘In order to better understand the specific substituent effects on the electrochemical oxidation process of β-O-4 bond, a series of methoxyphenyl type β-O-4 dimer model compounds with different localized methoxyl groups, including 2-(2-methoxyphenoxy)-1-phenylethanone, 2-(2-methoxyphenoxy)-1-phenylethanol, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanol, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanol have been selected and their electrochemical properties have been studied experimentally by cyclic voltammetry, and FT-IR spectroelectrochemistry. Combining with electrolysis products distribution analysis and density functional theory calculations, oxidation mechanisms of all six model dimers have been explored. In particular, a total effect from substituents of both para-methoxy(on the aryl ring closing to Cα) and Cα-OH on the oxidation mechanisms has been clearly observed, showing a significant selectivity on the Cα-Cβbond cleavage induced by electrochemical oxidations.
文摘It is known that the pathogenicity of Plasmodium induces the breakdown of haemoglobin, which leads to the induction of oxidative stress. This study aimed to identify the possible effects of oxidative stress and antioxidant defence systems in symptomatic and asymptomatic Plasmodium falciparum malaria infection in children (1 - 15 years old) in the Mount Cameroon vicinity. This cross-sectional study involved blood samples collected from 473 children and examined for malaria parasitaemia. Full blood counts were performed using an automated haemoanalyser. Serum oxidative stress status (malondialdehyde (MDA), nitric oxide (NO), reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD) and vitamin C (Vit C)) were each determined by colorimetric enzymatic assays. The prevalence of malaria parasite infection was 32.1% among the participants. Out of that, 62.5% of patients with parasitaemia were symptomatic. Anaemia prevalence increased significantly with parasite density. MDA levels were significantly higher in patients with malaria symptoms than in those without symptoms. A significant and positive correlation was detected between MDA (r = 0.831, P < 0.05), NO (r = 0.779, P < 0.05), and malaria parasite density while, a significant and negative relationship occurred between parasite density and GSH (r = ?0.763, P < 0.05) and Vit C (r = ?0.826, P < 0.05) levels, SOD (r = ?0.621, P < 0.05) and CAT (r = ?0.817, P < 0.05) activities. The SOD activity and GSH level significantly decreased (P < 0.05) with an increase in the MDA levels. These findings showed that MDA and nitric oxide levels increased both in malaria participants with or without symptoms. A similar decrease in the antioxidant defence system was observed in both symptomatic and asymptomatic patients. Therefore, there is a need to develop public health policies that encourage routine diagnosis and treatment of malaria in seemingly healthy people (asymptomatic cases), and this will play an essential role in controlling malaria in tropical countries.
基金Supported by the Ministry of Science and Information&Communication Technology(Grant No.MOSICT/Sha-9/PRC-24/2009-2010/(Part-1)/BS72/192.date-03/12/2009),Government of Bangladesh
文摘Objective:To investigate the inflammatory and antioxidant activities of ethanolie extract of aerial part of Vernonia patula(Dryand.)Merr(EAV).Methods:The anti-inflammatory activity of EAV was studied using carrageenan and histamine-induced rat paw edema test at different doses(100.200 and 400 mg/kg body weight).DPPH free radical scavenging,nitric oxide scavenging,reducing power and Fe^(2+)ion chelating ability were used for determining antioxidant activities.Results:The EAV,at the dose of 400 mg/kg,showed a significant anti-inflammatory activity(P<0.01)both in the carrageenan and histamine-induced oedema test models in rats,showing62.86%and 64.42%reduction in the paw volume comparable to that produced by the standard drug indomethacin(67.26%and 66.01%)at 5 h respectively.In DPPH free radical scavenging test,IC_(50)value for EAV was found fairly significant 36.59μg/mL when compared to the IC_(50)value of the reference standards ascorbic acid 8.97μg/mL.The IC_(50)values of the extract and ascorbic acid were 47.72 and 12.39μg/mL,respectively in nitric oxide scavenging assay.The IC_(50)value of the EAV(33.59μg/mL)as percentage of Fe^(2+)ion chelating ability was also found significant compared to that of EDTA(9.16μg/mL).The maximum absorbance for reducing power assay was found to be1.928 at 100μg/mL when compared to 2.449 for standard ascorbic acid.The total phenolic content was 198.81 mg/g of gallic acid equivalent.Acute toxicity test showed that the plant might be safe for pharmacological uses up to a dose level of 3200 mg/kg of body weight in rats.Conclusions:Therefore,the obtained results suggest the acute anti-inflammatory and antioxidant activities of the EAV and thus provide the scientific basis for the traditional uses of this plant part as a remedy for inflammations.
文摘Objective: To determine the bioactive compounds of Orostachys japonicus(O. japonicus)(Maxim.) A. Berger extraction by different solvents(70% ethanol or water) and to evaluate the in vitro antioxidant and anti-inflammatory activities. Methods: Total polyphenol, flavonoid, and anthocyanin contents in O. japonicus extract were measured. Antioxidant activities were determined by DPPH, ABTS, and superoxide radical-scavenging ability assays. Anti-inflammatory activities were evaluated by nitric oxide production, tumor necrosis factor-α, and interleukin-6 expression techniques. Results: Extraction with 70% ethanol yielded the highest total polyphenol(60.03 mg/g dry weight) and flavonoid(55.50 mg/g dry weight) contents. The total anthocyanin contents in 70% ethanol and water extracts were 57.25 and 91.71 mg/g dry weight, respectively. The 70% ethanol extract also showed stronger antioxidant activity than the water extract. Antioxidant activity and reducing power increased with the increasing concentration of O. japonicus extract. O. japonicus extract at 0-400 μg/m L did not affect the growth of RAW 264.7 cells, whereas dose-dependent inhibition of nitric oxide, tumor necrosis factor-α, and interleukin-6 production was observed.Conclusions: O. japonicus inhibits oxidative and inflammatory reactions with potentially positive health-related effects.
文摘Because of their high efficiency, antibiotics have long been the primary treatment for infections, but the rise of drug-resistant pathogens has become a therapeutic concern. Nanoparticles, as novel biomaterials, are currently gaining global attention to combat them. Drug-resistant diseases may need the use of nanoparticles as a viable therapeutic option. By altering target locations and enzymes, decreasing cell permeability, inactivating enzymes, and increasing efflux by overexpressing efflux pumps, they can bypass conventional resistance mechanisms. Therefore, understanding how metal and metal oxide nanoparticles affect microorganisms that are resistant to antimicrobial drugs is the main objective of this review. Accordingly, the uses of metal and metal oxide nanoparticles in the fight against drug-resistant diseases appear promising. However, their mechanism of action, dose, and possible long-term effects require special attention and future research. Furthermore, repeated use of silver nanoparticles may cause gram-negative microorganisms to acquire resistance, necessitating additional study.
基金Supported by the Institute of Research and Development,Walailak University,Thailand(Grant No.WU55304)
文摘Objective: To determine the cytotoxicity, reduction in nitric oxide production and antioxidative activity of the aqueous leaf extract from Tithonia diversifolia(T. diversifolia) in an in vitro model.Methods: Leaves of T. diversifolia were collected from natural habitats and extracted with distilled water using the decoction method. The cytotoxic effect of the extract in terms of cell viability was determined using RAW264.7 cells and human peripheral blood mononuclear cells(PBMCs) via the mitochondrial respiration method using the MTT reagent. The effect of the extract on lipopolysaccharide(LPS)-induced nitric oxide production in RAW264.7 cells was measured using the Griess reagent. The chemical antioxidant was evaluated by ABTS- and DPPH-radical scavenging assays.Results: The half-maximal cytotoxic concentration values were 145.87 mg/m L and73.67 mg/m L for human PBMCs and RAW264.7 cells, respectively. In the presence of phytohemagglutinin-M, the IC_(50) on PBMCs proliferation was 4.42 mg/m L. The noncytotoxic range of the extracts inhibited LPS-induced nitrite production in RAW264.7 cells with an IC_(50) value of 11.63 mg/m L. To determine the anti-oxidative properties, the N-acetyl cysteine equivalent antioxidant capacity of the extract was(32.62 ± 1.87) and(20.99 ± 2.79)mg N-acetyl cysteine/g extract, respectively determined by the ABTS-radical and DPPHradical assay. However, the extract did not confer death protection in a hydrogen peroxideinduced RAW264.7 co-culturing model.Conclusions: Our study demonstrated the immunomodulation caused by the aqueous leaf extract of T. diversifolia, resulting from the inhibition of phytohemagglutinin-Minduced PBMCs proliferation and LPS-induced nitric oxide production in RAW264.7macrophages. Although the anti-oxidative activity was presented in the chemical-based anti-oxidant assay, the extract cannot protect cell death from stress conditions.
文摘Chrysanthellum americanum (L.) Vatke is a medicinal plant used by the traditional healers to treat epilepsy and associated memory impairment. This work aims at evaluating the anticonvulsant effects of Chrysanthellum americanum aqueous extract in mice pilocarpine model of epilepsy and associated memory loss. Mice were administered orally Chrysanthellum americanum aqueous extract (27.69, 69.22, 138.45, 276.9 mg/kg, prepared from the whole part) for test groups, intraperitoneally 300 mg/kg sodium valproate for the positive control group or orally 10 mL/kg distilled water for the negative control group, respectively, during a period of seven consecutive days. On the first day, temporal lobe epilepsy was induced by intraperitoneal injection of 360 mg/kg pilocarpine one hour after the administration of different treatment to mice, and the occurrence of status epilepticus was evaluated. On the second day, the anticonvulsant property was measured after the intraperitoneal injection of a sub-convulsive dose of picrotoxin (1 mg/kg). On the seventh day, the anti-amnesic properties of the extract were evaluated in the epileptic mice using the T-maze and open field paradigms. The results show that Chrysanthellum americanum extract significantly (p Chrysanthellum americanum (276.9 mg/kg) likewise sodium valproate (300 mg/kg) significantly (p Chrysanthellum americanum aqueous extract has anticonvulsant effects against pilocarpine induced-epileptic seizures and memory impairment. These properties could be mediated by the amelioration of antioxidant defense system and cholinergic neurotransmission in epileptic mice, which could partly justify the use of Chrysanthellum americanum in the traditional medicine for the treatment of epilepsy.
基金supported by the National Natural Science Foundation of China (52173273)Fundamental Research Funds for the Central Universities (2022CX11013)+2 种基金Shanxi Province Science Foundation for Youths (No.202203021212391)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi (No.2022L253)Institute Foundation Project of China Academy of Railway Sciences Corporation Limited Metals and Chemistry Research Institute (No.2023SJ02)。
文摘The Mn-based oxide cathode with enriched crystal phase structure and component diversity can provide the excellent chemistry structure for Na-ion batteries.Nevertheless,the broad application prospect is obstructed by the sluggish Na^(+)kinetics and the phase transitions upon cycling.Herein,we establish the thermodynamically stable phase diagram of various Mn-based oxide composites precisely controlled by sodium content tailoring strategy coupling with co-doping and solid-state reaction.The chemical environment of the P2/P'3 and P2/P3 biphasic composites indicate that the charge compensation mechanism stems from the cooperative contribution of anions and cations.Benefiting from the no phase transition to scavenge the structure strain,P2/P'3 electrode can deliver long cycling stability(capacity retention of 73.8%after 1000 cycles at 10 C)and outstanding rate properties(the discharge capacity of 84.08 mA h g^(-1)at 20 C)than P2/P3 electrode.Furthermore,the DFT calculation demonstrates that the introducing novel P'3 phase can significantly regulate the Na^(+)reaction dynamics and modify the local electron configuration of Mn.The effective phase engineering can provide a reference for designing other high-performance electrode materials for Na-ion batteries.