Potential role and therapeutic implications of glutathione peroxidase 4 in the treatment of Alzheimer's disease

Alzheimer's disease is an age-related neurodegenerative disorder with a complex and incompletely understood pathogenesis. Despite extensive research, a cure for Alzheimer's disease has not yet been found. Oxidative stress mediates excessive oxidative responses, and its involvement in Alzheimer's disease pathogenesis as a primary or secondary pathological event is widely accepted. As a member of the selenium-containing antioxidant enzyme family, glutathione peroxidase 4 reduces esterified phospholipid hydroperoxides to maintain cellular redox homeostasis. With the discovery of ferroptosis, the central role of glutathione peroxidase 4 in anti-lipid peroxidation in several diseases, including Alzheimer's disease, has received widespread attention. Increasing evidence suggests that glutathione peroxidase 4 expression is inhibited in the Alzheimer's disease brain, resulting in oxidative stress, inflammation, ferroptosis, and apoptosis, which are closely associated with pathological damage in Alzheimer's disease. Several therapeutic approaches, such as small molecule drugs, natural plant products, and non-pharmacological treatments, ameliorate pathological damage and cognitive function in Alzheimer's disease by promoting glutathione peroxidase 4 expression and enhancing glutathione peroxidase 4 activity. Therefore, glutathione peroxidase 4 upregulation may be a promising strategy for the treatment of Alzheimer's disease. This review provides an overview of the gene structure, biological functions, and regulatory mechanisms of glutathione peroxidase 4, a discussion on the important role of glutathione peroxidase 4 in pathological events closely related to Alzheimer's disease, and a summary of the advances in small-molecule drugs, natural plant products, and non-pharmacological therapies targeting glutathione peroxidase 4 for the treatment of Alzheimer's disease. Most prior studies on this subject used animal models, and relevant clinical studies are lacking. Future clinical trials are required to validate the therapeutic effects of strategies targeting glutathione peroxidase 4 in the treatment of Alzheimer's disease.

Gastrointestinal Ulcers Treatment: Plants and Recipes Used by Herbalists of Abomey-Calavi and Cotonou Districts, Southern Benin

This study set out to identify plants and recipes used by herbalists in the municipalities of Abomey-Calavi and Cotonou to treat gastrointestinal ulcers and to characterize the distribution of their knowledge. An ethno-pharmacological survey was carried out in which informants who agreed freely were interviewed using a semi-structured questionnaire. A total of 85 herbalists were surveyed. The data were processed with Microsoft Excel to calculate the relative frequencies of citation of the various species mentioned by the herbalists and various indices including Simpson’s Index were adapted to test the distribution of their knowledge. Multiple regression and correspondence analysis were performed using R studio. Our results revealed that the Dendi, Ifè and Mina, all equitable in their knowledge of anti-ulcer plants, are likely to know more than the other ethnic groups. On the other hand, respondents practicing Islam are more likely to know many antiulcer plants than those practicing Vodoun and Christianity. This constant distribution of knowledge of anti-ulcer plants among the Dendi, Ifè and Mina, three different ethnic groups seems normal and attests to the fusion between these different ethnic groups in view of this knowledge. A total of 70 anti-ulcer recipes, made from 71 species of medicinal plants or non-floristic resources were recorded. Vitellaria paradoxa, Parkia biglobosa and Ocimum gratissimum were the top 03 most frequently cited in descending order of frequency. All the species cited are grouped into 44 botanical families among which the Fabaceae, Lamiaceae and Sapotaceae were strongly represented. Benin’s flora abounds in a diversity of medicinal plant species known to herbalists in Abomey-Calavi and Cotonou for the treatment of gastrointestinal ulcers. The results of this study constitute a good archive for the selection of plant species for in-depth studies with a view to formulating improved traditional medicines for gastrointestinal ulcers.

The role of a novel antibacterial substance,cyclic opine-producing Lacticaseibacillus rhamnosus LS8 in ameliorating ulcerative colitis:a fecal microbiota transplantation study

Intestinal microbiota imbalance may worsen the progression of ulcerative colitis(UC).Lacticaseibacillus rhamnosus LS8(LR)has the potential ability to regulate microbiota through producing a novel antibacterial substance,cyclic opine:cycloalanopine.This study aimed to investigate whether LR could ameliorate dextran sulfate sodium-induced UC in mice via modulating intestinal microbiota using fecal microbiota transplantation(FMT)experiment.The results showed that both LR and FMT attenuated UC as evidenced by 1)alleviating disease activity index and colonic pathology;2)up-regulating MUCs and tight junction proteins;3)increasing oxidative mediators and decreasing antioxidant mediators;4)down-regulating proinflammatory cytokines and chemokines.These results were mainly attributable to the microbiota-regulating effect of LR,including increasing beneficial bacteria(like Akkermansia)and its related SCFAs,while decreasing harmful bacteria(like Proteobacteria)and its related LPS,thereby suppressing the hyperactivation of TLR4/NF-κB pathway.Consequently,LR can alleviate UC and is a potential dietary supplement to attenuate UC.

Natural product-induced oxidative stress-synergistic anti-tumor effects of chemotherapeutic agents

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.

Xiaotan Tongfu granules contribute to the prevention of stress ulcers

AIM:To investigate the efficacy and potential mechanism of Xiaotan Tongfu granules(XTTF)in stress ulcers.METHODS:One hundred sixty rats were randomly divided into 4 groups(n=10)as follows:the model group(MP group),the control group(CP group),the ranitidine group(RP group)and the XTTF granule group(XP group).Rats in the MP group received no drugs,rats in the CP group received 0.2 mL of a 0.9%sodium chloride solution via oral gavage,and rats in the RP and XP groups received the same volume of ranitidine(50 mg/kg)or XTTF granule(4.9 g/kg).The cold-restraint stress model was applied to induce stress ulcers after 7 consecutive days of drug administration.Afterwards,rats were sacrificed at 0,3,6 and24 h.Gastric pH was measured by a precise pH meter;gastric emptying rate(GER)was measured by using a methylcellulose test meal;myeloperoxidase activity(MPO),macrophage migration inhibitory factor(MIF),proliferating cell nuclear antigen(PCNA),and heat shock protein 70(HSP70)were measured by immunohistochemical staining;and mucosal cell apoptosis was measured by transferase dUTP nick end labeling.RESULTS:In the cold-restraint stress model,the development of stress ulcers peaked at 3 h and basically regressed after 24 h.Gastric lesions were significantly different in the RP and XP groups at each time point.Interestingly,although this index was much lower in the RP group than in the XP group immediately following stress induction(7.00±1.10 vs 10.00±1.79,P<0.05.Concerning gastric pH,between the RP and XP groups,we detected a statistically significant difference immediately after stress induction(0 h:4.56±0.47 vs 3.34±0.28,P<0.05)but not at any of the subsequent time points.For GER,compared to the RP group,GER was remarkably elevated in the XP group because a statistically significant difference was detected(3 h:46.84±2.70 vs 61.16±5.12,P<0.05;6 h:60.96±6.71 vs 73.41±6.16,P<0.05;24 h:77.47±3.17 vs 91.31±4.34,P<0.05).With respect to MPO and MIF,comparisons between the RP and XP groups revealed statistically significant differences at 3 h(MPO:18.94±1.20 vs 13.51±0.89,P<0.05;MIF:150.67±9.85 vs 122.17±5.67,P<0.05)and 6 h(MPO:13.22±1.54 vs 8.83±0.65,P<0.05;MIF:135.50±9.46 vs 109.83±6.40,P<0.05).With regard to HSP70,HSP70 expression was significantly increased in the RP and XP groups at 3 and 6 h compared to the MP and CP groups.In addition,comparing the RP and XP groups also showed statistically significant differences at 3 and 6 h.The expression of PCNA was higher in the RP and XP groups 3 h after stress induction.Between these two groups,small but statistically significant differences were observed at all of the time points(3 h:69.50±21.52 vs 79.33±15.68,P<0.05;6 h:107.83±4.40 vs 121.33±5.71,P<0.05;24 h:125.33±5.65 vs 128.50±14.49,P<0.05)except 0 h.With regard to apoptosis,the apoptotic activity in the RP and XP groups was significantly different from that in the MP and CP groups.The XP group exhibited a higher inhibition of cell apoptosis than the RP group at3 h(232.58±24.51 vs 174.46±10.35,P<0.05)and6 h(164.74±18.31 vs 117.71±12.08,P<0.05).CONCLUSION:The Xiaotan Tongfu granule was demonstrated to be similar to ranitidine in preventing stress ulcers.It exhibited multiple underlying mechanisms and deserves further study.

Tilapia Head Glycolipid Alleviates Indomethacin-Induced Gastric Ulcer via Regulating Oxidative Stress and Inflammation Through COX/PGE2 Signaling Pathway in Adult Rats

The aim of this experiment was to investigate the ameliorative effect and molecular mechanism of tilapia head glycolipid(TH-GL)on indomethacin(IDM)-induced gastric ulcer in male Sprague Dawley(SD)rats.The gastric ulcer model was established by oral administration of 30mgkg^(-1) IDM after 7 days of TH-GL or omeprazole(OME)administration in rats.Then the macroscopic gastric injury symptoms,gastric mucosa protective factor cyclooxygenase 1(COX-1),cyclooxygenase 2(COX-2),prostaglandin E_(2)(PGE_(2)),the levels of oxidative stress,and inflammatory cytokine expression levels in the rats were analyzed.The experimental results showed that multiple ulcers appeared on the gastric surface of the rats in the model group.Compared to the model group,TH-GL significantly alleviated gastric ulcers and reduced the gastric damage index in rats.In addition,TH-GL significantly promoted the expression of constitutive enzyme COX-1 while inhibited the expression of inducible enzyme COX-2,and make PGE2 maintain at normal levels.TH-GL also inhibited oxidative stress and inflammatory responses,increased superoxide dismutase(SOD)activity and glutathione(GSH)content,decreased the level of malondialdehyde(MDA)and the content of pro-inflammatory factor.In conclusion,these results suggested that TH-GL could maintain the expression levels of COX-1 and PGE2 while inhibit the expression of COX-2 in the gastric of rat and then prevent IDM-induced gastric ulcer,which may be related to the regulation of oxidative stress and inflammatory response.Therefore,TH-GL might be a new option for the prevention of gastric diseases induced by IDM.

Rheological study of methane gas hydrates in the presence of micron-sized sand particles

Natural gas hydrates,intricate crystalline structures formed by water molecules and small gas molecules,have emerged as a significant and globally impactful clean energy resource.However,their commercial exploitation faces challenges,particularly operational disruptions caused by sand-related blockages.Understanding the rheological properties of hydrate slurry,especially in the presence of micron-sized sand particles,is imperative for ensuring the flow assurance of subsea hydrate exploitation.This study extensively investigates the rheological properties of sand-containing hydrate slurries.The findings reveal that these slurries exhibit non-Newtonian fluid characteristics,including yield stress,thixotropy,and shear-thinning behavior.Solid-like elastic features are observed in sand-containing hydrate slurries before yielding,transitioning to viscous behavior after yielding.Even with a minimal amount of sand,both static yield stress and yield strain experience substantial changes,correlating with the increase in sand concentration.The research conclusively establishes the thixotropic nature of sand-hydrate slurries,where the viscosity decay rate is directly influenced by the shear rate.These insights aim to contribute comprehensively to the development of effective flow assurance strategies,ensuring the safe and stable operation of subsea hydrate exploitation.

Targeting oxidative stress with natural products: A novel strategy for esophageal cancer therapy

Esophageal cancer(ESC)is a malignant tumor that originates from the mucosal epithelium of the esophagus and is part of the digestive tract.Although the exact pathogenesis of ESC has not been fully elucidated,excessive oxidative stress is an important characteristic that leads to the development of many cancers.Abnormal expression of several proteins and transcription factors contributes to oxidative stress in ESCs,which alters the growth and proliferation of ESCs and promotes their metastasis.Natural compounds,including alkaloids,terpenes,polyphenols,and xanthine compounds,can inhibit reactive oxygen species production in ESCs.These compounds reduce oxidative stress levels and subsequently inhibit the oc-currence and progression of ESC through the regulation of targets and pathways such as the cytokine interleukins 6 and 10,superoxide dismutase,the NF-+ACY-kappa+ADs-B/MAPK pathway,and the mammalian Nrf2/ARE target pathway.Thus,targeting tumor oxidative stress has become a key focus in anti-ESC therapy.This review discusses the potential of Natural products(NPs)for treating ESCs and summarizes the application prospects of oxidative stress as a new target for ESC treatment.The findings of this review provide a reference for drug development targeting ESCs.Nonetheless,further high-quality studies will be necessary to determine the clinical efficacy of these various NPs.

Sirtuin 1 alleviates endoplasmic reticulum stress-mediated apoptosis of intestinal epithelial cells in ulcerative colitis

BACKGROUND Sirtuin 1(SIRT1)is a nicotinamide adenine dinucleotide(NAD+)-dependent protein deacetylase that is involved in various diseases,including cancers,metabolic diseases,and inflammation-associated diseases.However,the role of SIRT1 in ulcerative colitis(UC)is still confusing.AIM To investigate the role of SIRT1 in intestinal epithelial cells(IECs)in UC and further explore the underlying mechanisms.METHODS We developed a coculture model using macrophages and Caco-2 cells.After treatment with the SIRT1 activator SRT1720 or inhibitor nicotinamide(NAM),the expression of occludin and zona occludens 1(ZO-1)was assessed by Western blot analysis.Annexin V-APC/7-AAD assays were performed to evaluate Caco-2 apoptosis.Dextran sodium sulfate(DSS)-induced colitis mice were exposed to SRT1720 or NAM for 7 d.Transferase-mediated dUTP nick-end labeling(TUNEL)assays were conducted to assess apoptosis in colon tissues.The expression levels of glucose-regulated protein 78(GRP78),CCAAT/enhancerbinding protein homologous protein(CHOP),caspase-12,caspase-9,and caspase-3 in Caco-2 cells and the colon tissues of treated mice were examined by quantitative real-time PCR and Western blot.RESULTS SRT1720 treatment increased the protein levels of occludin and ZO-1 and inhibited Caco-2 apoptosis,whereas NAM administration caused the opposite effects.DSS-induced colitis mice treated with SRT1720 had a lower disease activity index(P<0.01),histological score(P<0.001),inflammatory cytokine levels(P<0.01),and apoptotic cell rate(P<0.01),while exposure to NAM caused the opposite effects.Moreover,SIRT1 activation reduced the expression levels of GRP78,CHOP,cleaved caspase-12,cleaved caspase-9,and cleaved caspase-3 in Caco-2 cells and the colon tissues of treated mice.CONCLUSION SIRT1 activation reduces apoptosis of IECs via the suppression of endoplasmic reticulum stress-mediated apoptosis-associated molecules CHOP and caspase-12.SIRT1 activation may be a potential therapeutic strategy for UC.

Experimental study on mechanism and protection of stress ulcer produced by explosive noise

AIM To establish an experimental model of stress ulcer produced by explosive noise, and to probe into its mechanism and protection. METHODS The country standard Wistar white rats were randomly divided into control group ( n =8), which were neither stimulated nor protected, and stimulating group (divided into subgroups A, B and C, including 8 rats each which were decapitated to draw blood for test immediately, 12 hours and 24 hours after stimulation) and prevention group (divided into subgroups A, B and C, having 8 rats each, subgroup A was given cimetidine, B anisodamine and C both drugs). Firing noises of submachine guns were used as inflicting factor. The rats were fasted for 24 hours and stimulated by firing noise for 12 hours. The change of ulcer index, gastric mucosal and related serum hormones were observed. RESULTS Stress ulcer was significant in the stimulating group, and its ulcer index (8 6±0 6) was remarkably higher than that in both the control group and prevention group (0 3±0 1, P <0 01). Its serum gastrin (Gas ng/L , 294±163 vs 63±40, P <0 01) and endothelin (ET ng/L , 181±57 vs 135±42, P <0 01) were apparently higher than those in the control group, and its serum nitric oxide (NO) level was conspicuously lower than that in the control group ( ng/L , 0 2±0 1 vs 0 8±0 5, P <0 05), while the serum gastrin level ( ng/L , 556±225) in prevention group was distinctly higher than that in both the control ( P <0 01) and stimulating group ( P <0 05). There were no significant differences in the changes of ET and NO between the control and the stimulating groups. CONCLUSION Stress ulcer model of rats can be successfully established by the stimulation of explosive noise. Gas, ET and NO are related to the formation of stress ulcer, and play an important role in its mechanism. Hepatic function affected by noise is observed in this experiment.

Effects of acupuncturing Tsusanli (S_T36) on expression of nitric oxide synthase in hypothalamus and adrenal gland in rats with cold stress ulcer

AIM： To study the protective effect of acupuncturing Tsusanli （ST36） on cold stress ulcer, and the expression of nitric oxide synthase （NOS） in hypothalarnus and adrenal gland. METHODS： Ulcer index in rats and RT-PCR were used to study the protective effect of acupuncture on cold stress ulcer, and the expression of NOS in hypothalamus and adrenal gland. Images were analyzed with semi-quantitative method. RESULTS： The ulcer index significantly decreased in rats with stress ulcer. Plasma cortisol concentration was up regulated during cold stress, which could be depressed by pre-acupuncture. The expression of NOS1 in hypothallamus increased after acupuncture. The increased expression of NOS2 was related with stress ulcer, which could be decreased by acupuncture. The expression of NOS3 in hypothalamus was similar to NOS2, but the effect of acupuncture was limited. The expression of NOS2 and NOS3 in adrenal gland increased after cold stress, only the expression of NOS1 could be repressed with acupuncture. There was no NOS2 expression in adrenal gland in rats with stress ulcer. CONCLUSION： The protective effect of acupuncturing Tsusanli （ST36） on the expression of NOS in hypothalamus and adrenal gland can be achieved.

Stress ulcer prophylaxis guidelines:Are they being implemented in Lebanese health care centers?

AIM:To evaluate the current practice of stress ulcer prophylaxis (SUP) in Lebanese Health care centers.METHODS:A multi-center prospective chart review study was conducted over 8 mo.A questionnaire was distributed to pharmacy students who collected data on demographics,SUP medications,dose,route,duration and associated risk factors.The appropriateness of SUP use was determined as per American Society of Health-System Pharmacists guidelines.Institutional review board approval was obtained from each hospital center.RESULTS:A total of 1004 patients were included.67% of the patients who received prophylaxis did not have an indication for SUP.The majority (71.6%) of the patients who were administered parenteral drugs can tolerate oral medications.Overall,the regimen of acid-suppressant drugs was suboptimal in 87.6% of the sample.This misuse was mainly observed in non-teaching hospitals.CONCLUSION:This study highlighted the need,in Lebanese hospitals,to establish clinical practice guidelines for the use of SUP;mainly in non-critical care settings.

Proteomics of the mediodorsal thalamic nucleus of rats with stress-induced gastric ulcer

BACKGROUND Stress-induced gastric ulcer(SGU) is one of the most common visceral complications after trauma. Restraint water-immersion stress(RWIS) can cause serious gastrointestinal dysfunction and has been widely used to study the pathogenesis of SGU to identify medications that can cure the disease. The mediodorsal thalamic nucleus(MD) is the centre integrating visceral and physical activity and contributes to SGU induced by RWIS. Hence, the role of the MD during RWIS needs to be studied.AIM To screen for differentially expressed proteins in the MD of the RWIS rats to further elucidate molecular mechanisms of SGU.METHODS Male Wistar rats were selected randomly and divided into two groups, namely, a control group and an RWIS group. Gastric mucosal lesions of the sacrificed rats were measured using the erosion index and the proteomic profiles of the MD were generated through isobaric tags for relative and absolute quantitation(iTRAQ) coupled with two-dimensional liquid chromatography and tandem mass spectrometry. Additionally, iTRAQ results were verified by Western blot analysis.RESULTS A total of 2853 proteins were identified, and these included 65 dysregulated(31 upregulated and 34 downregulated) proteins(fold change ratio ≥ 1.2). Gene Ontology(GO) analysis showed that most of the upregulated proteins are primarily related to cell division, whereas most of the downregulated proteins are related to neuron morphogenesis and neurotransmitter regulation. Ingenuity Pathway Analysis revealed that the dysregulated proteins are mainly involved in the neurological disease signalling pathways. Furthermore, our results indicated that glycogen synthase kinase-3 beta might be related to the central mechanismthrough which RWIS gives rise to SGU.CONCLUSION Quantitative proteomic analysis elucidated the molecular targets associated with the production of SGU and provides insights into the role of the MD. The underlying molecular mechanisms need to be further dissected.

Research on stress-induced apoptosis of natural killer cells and the alteration of their killing activity in mouse liver

AIM:To investigate the stress-induced apoptosis of natural killer(NK)cells and the changes in their killing activity in mouse livers.METHODS:A restraint stress model was established in mice.Flow cytometry was employed to measure the percentage of NK cells and the changes in their absolute number in mouse liver.The cytotoxicity of hepatic and splenic NK cells was assessed against YAC-1 target cells via a 4 h 51Cr-release assay.RESULTS:The restraint stress stimulation induced the apoptosis of NK cells in the liver and the spleen,which decreased the cell number.The number and percentage of NK cells in the spleen decreased.However,the number of NK cells in the liver decreased,whereas the percentage of NK cells was significantly increased.The apoptosis of NK cells increased gradually with prolonged stress time,and the macrophage-1(Mac-1)+NK cells were more susceptible to apoptosis than Mac-1-NK cells.Large numbers of Mac-1-NK cells in the liver,which are more resistant to stress-induced apoptosis,were observed than the Mac-1-NK cells in the spleen.The stress stimulation diminished the killing activity of NK cells in the spleen was significantly decreased,but the retention of numerous Mac-1-NK cells in the liver maintained the killing ability.CONCLUSION:Significant stress-induced apoptosis was observed among Mac-1+NK cells,but not Mac-1-NK cells in the mouse liver.Stress stimulation markedly decreased the killing activity of NK cells in the spleen but remained unchanged in the liver.

Selective decrease in colonic CD56^+ T and CD161^+ T cells in the inflamed mucosa of patients with ulcerative colitis

AIM： To investigate the role of local colonic mucosal NK receptor-positive T （NKR＋ T） cells in the regulation of intestinal inflammation, we analyzed the population and function of these cells in ulcerative colitis （UC）. METHODS： Colonic mucosal tissues were obtained from colonoscopic biopsies of the descending colon from 96 patients with UC （51 endoscopically uninflamed, 45 inflamed） and 18 normal controls. Endoscopic appearance and histologic score at the biopsied site were determined by MaLts＇ classification. A single cell suspension was prepared from each biopsy by collagenase digestion. Two NKR^＋ T cell subsets, CD56^＋ （CD56^＋CD3^＋） T cells and CD161＋ （CD161^＋CD3^＋） T cells, were detected by flow cytometric analysis. Intracellular cytokine analysis for anti-inflammatory cytokine interleukin-10 （IL-10） was performed by in vitro stimulation with phorbol-myristateacetate （PMA） and ionomycin. RESULTS： CD56^＋ T cells and CD161^＋ T cells are present in the normal human colon and account for 6.7% and 21.3% of all mononuclear cells, respectively. The populations of both CD56＋ T cells and CD161^＋ T cells were decreased significantly in the inflamed mucosa of UC. In contrast, the frequency of conventional T cells （CD56 CD3^＋ cells and CD161CD3^＋ cells） was similar among the patient and control groups. The populations of NKR^＋ T cells were correlated inversely with the severity of inflammation, which was classified according to the endoscopic and histologic Marts＇ criteria. Interestingly, approximately 4% of mucosal NKR＋ T cells expressing IL-10 were detected by in vitro stimulation with PMA and ionomycin.CONCLUSION： Selective reduction in the population of colonic mucosal NKR＋T cells may contribute to the development of intestinal inflammation in UC.

Photosynthetic Characteristics of Clerodendrum trichotomum Thumb. Responses to Drought, Salt and Water-logging Stresses

In order to reveal the photosynthetic characteristics of C. trichotomum responses to drought, salt and water-logging stresses, one-year-old potted seedlings were taken as materials, and the several stresses including natural drought, submergence stress, water-logging and different salt treatments （0.2%, 0.4%, 0.6% and 0.8% NaCl） were carried out on August 15, 2012. The morphological and photosynthetic characteristics were observed and determined. The results showed that adverse enviromental stress had a significant effect on the morphological changes and photosynthetic characteristics of C. trichotomum. On the 14th day after natural drought, the leaves wilted and could not recovery at night, and 60% of the seedlings could recover after re-watering. From the 7th day to the 10th day after submergence stress treatment, the 2nd and the 3rd leaves at the base of 60% seedling turned yellow and the lenticels were observed. At the early stage of water-logging stress, white lenticels appeared at the base of seedlings, and the leaves wilted, chlorina and fallen off on the 8th day. A large number of leaves fallen off under 0.6% NaCl or more salt stress, and even the whole plant died. The chlorophyll content, net photosynthetic rate （Pn） and transpiration rate （Tr） decreased gradually with the stress process, such as 8 days after natural drought, less than 0.4% salt stress and water-logging stress, but the changes were not significant compared with those of the control. With the increase of the stress intensity and the prolonged time, the changes of photosynthetic index were significant. All the results indicated that C. trichotomum had a certain degree of tolerance to drought, water and salt, but it was not suitable for living, in water-logging condition for a long time.

Roles of Adinandra nitida(Theaceae) and camellianin A in HCl/ethanol-induced acute gastric ulcer in mice

Gastric ulcer is a global health concern nowadays. Adinandra nitida, known as Shibi tea, is a flavonoidrich plant found in South China. A. nitida possesses many healthy properties, such as antioxidation and reducing blood pressure. However, its effects on gastric ulcer have not been investigated. This study aimed to investigate the effects of the Shibi tea water extract(STE) and its main flavonoid camellianin A(CA) in hydrochloric acid(HCl) and ethanol(Et OH)-induced acute gastric ulcer in mice. Administration of CA and STE for continuous two days after stimulation by HCl/Et OH significantly attenuated the deterioration of gastric mucosal damage by lowering the gross gastric mucosal index, histopathological injury index, the oxidative stress, the expression of the inflammatory cytokines TNF-α and IL-6, and the expression of inflammatory mediators i NOS and COX-2. Western blotting and immunohistochemistry analysis showed that CA and STE regulated the inflammatory signaling pathway protein levels of IκB-α and NF-κB. Taken together, our study verified that CA and STE have antioxidative and anti-inflammatory effects in gastric ulcer mice. We propose that A. nitida should be developed as natural functional food for acute gastric ulcer patients base on the gastroprotective effects of STE and its main flavonoid CA.

The Discrete-Analytical Solution Method for Investigation Dynamics of the Sphere with Inhomogeneous Initial Stresses

The paper deals with a development of the discrete-analytical method for the solution of the dynamical problems of a hollow sphere with inhomogeneous initial stresses.The examinations are made with respect to the problem on the natural vibration of the hollow sphere the initial stresses in which is caused by internal and external uniformly distributed pressure.The initial stresses in the sphere are determined within the scope of the exact equations of elastostatics.It is assumed that after appearing this static initial stresses the sphere gets a dynamical excitation and mechanical behavior of the sphere caused by this excitation is described with the so-called three-dimensional linearized equations of elastic wave propagation in initially stressed bodies.For the solution of these equations,which have variable coefficients,the discrete analytical solution method is developed and applied.In particular,it is established that the convergence of the numerical results with respect to the number of discretization is very acceptable and applicable for the considered type dynamical problems.Numerical results on the influence of the initial stresses on the values of the natural frequencies of the hollow sphere are also presented and these results are discussed.

Role of dietary polyphenols in the management of peptic ulcer

Peptic ulcer disease is a multifactorial and complex disease involving gastric and duodenal ulcers.Despite medical advances,the management of peptic ulcer and its complications remains a challenge,with high morbidity and death rates for the disease.An accumulating body of evidence suggests that,among a broad reach of natural molecules,dietary polyphenols with multiple biological mechanisms of action play a pivotal part in the management of gastric and duodenal ulcers.The current review confirmed that dietary polyphenols possess protective and therapeutic potential in peptic ulcer mediated by:improving cytoprotection,re-epithelialization,neovascularization,and angiogenesis; up-regulating tissue growth factors and prostaglandins; down-regulating anti-angiogenic factors; enhancing endothelial nitric oxide synthasederived NO; suppressing oxidative mucosal damage; amplifying antioxidant performance,antacid,and antisecretory activity; increasing endogenous mucosal defensive agents; and blocking Helicobacter pylori colonization associated gastric morphological changes and gastroduodenal inflammation and ulceration.In addition,anti-inflammatory activity due to downregulation of proinflammatory cytokines and cellular and int e r c e llular adhe s ion age nt s,s uppr e s s ing leukocyte-endothelium interaction,inhibiting nuclear signaling pathways of inflammatory process,and modulating intracellular transduction and transcription pathways have key roles in the anti-ulcer action of dietary polyphenols.In conclusion,administration of a significant amount of dietary polyphenols in the human diet or as part of dietary supplementation along with conventional treatment can result in perfect security and treatment of peptic ulcer.Further welldesigned preclinical and clinical tests are recommended in order to recognize higher levels of evidence for the confirmation of bioefficacy and safety of dietary polyphenols in the management of peptic ulcer.

Extraintestinal manifestations of inflammatory bowel disease, nitroxidative stress and dysbiosis: What is the link between them?

Inflammatory bowel disease(IBD),which includes Crohn’s disease and ulcerative colitis,has a not yet completely defined aetiology and is characterized by a progressive chronic inflammation that involves nitroxidative stress and dysbiosis.Extraintestinal manifestations can occur and affect several organs,including the liver and bile ducts,joints,skin,eyes,and less frequently,the heart,brain,and kidneys,increasing the risk of morbidity and mortality.These repercussions may be associated with the activity or severity of IBD.The present review proposes to report and analyse the participation of dysbiosis and nitroxidative stress in the genesis of extraintestinal manifestations,aiming to contribute to a better understanding of the disease and to focus on the development of individualized preventive and therapeutic strategies.