Structural and antioxidative properties of royal jelly protein by partial enzymatic hydrolysis

The objective of this study was to investigate the structural and antioxidative properties of royal jelly protein(RJP)at different degrees of hydrolysis(DH)by partial enzymatic hydrolysis. RJP was hydrolyzed by alcalase for 0 min, 15 min, 1 h, 5 h and 8 h to obtain hydrolysates at DH of 5.34%, 11.65%, 15.19%, 21.38% and 23.91%, respectively. With the increased DH, the RJP hydrolysates showed elevated antioxidative activities. The molecular weight of RJP hydrolysates was significantly decreased but their primary backbone kept unchanged. Analysis of circular dichroism spectra revealed that the enzymolysis reduced the content of α-helix but increased the contents of β-sheet, β-turn and random coil. Meanwhile, the surface hydrophobicity and fluorescence intensity of RJP hydrolysates were decreased and a red shift occurred. As the enzymolysis continued, the surface morphology of RJP was gradually changed from a sheet-like structure into microparticles. Changes in antioxidative activities and structures generally followed a DH-dependent manner, however these changes became insignificant for samples at DH beyond 20%. Taking into consideration of both effectiveness and productivity, the optimum enzymatic duration was determined at 5 h.

Restored intestinal integrity,nutrients transporters,energy metabolism,antioxidative capacity and decreased harmful microbiota were associated with IUGR piglet's catch-up growth before weanling

Background:Intrauterine growth restriction(IUGR)is a major inducer of higher morbidity and mortality in the pig industry and catch-up growth(CUG)before weanling could significantly restore this negative influence.But there was limited knowledge about the underlying mechanism of CUG occurrence.Methods:Eighty litters of newborn piglets were divided into normal birth weight(NBW)and IUGR groups according to birth weight.At 26 d,those piglets with IUGR but over average body weight of eighty litters of weaned piglets were considered as CUG,and the piglets with IUGR still below average body weight were considered as NCUG.This study was conducted to systemically compare the intestinal difference among NBW,CUG and NCUG weaned piglets considering the crucial role of the intestine for piglet growth.Results:The results indicated that the m RNA expression of nutrients(amino acids,glucose,and fatty acids)transporters,and mitochondrial electron transport chain(ETC)I were upregulated in CUG piglets'gut with improved morphology compared with those NCUG,as well as the ratio of P-AMPK/AMPK protein expression which is the indicator of energy metabolism.Meanwhile,CUG piglet's gut showed higher antioxidative capacity with increased SOD and GSHPx activity,decreased MDA levels,as well as higher m RNA expressions of Nrf2,Keap1,SOD,and GSH-Px.Furthermore,inflammatory parameters including TNF-α,IL-1β,IL-6,and IL-12 factors,and the activation of MAPK and NF-κB signaling pathways were significantly elevated in the NCUG intestine,while the protein expression of ZO-1,Occludin and Claudin-1 was reduced.The alpha diversity of fecal microbiota was higher in CUG piglets in contrast with NCUG piglets,and the increased beneficial bacteria and decreased pathogenic bacteria was also observed in CUG piglets.Conclusions:CUG piglet's intestine showed comprehensive restoration including higher nutrients transport,energy metabolism,antioxidant capacity,and intestinal physical barrier,while lower oxidative stress,inflammatory response,and pathogenic microbiota.

Endophytic Bacteria Promote the Growth of Suaeda glauca in Saline-Alkali Stress:Regulation of Osmotic Pressure and Antioxidative Defense System

Endophytic bacteria are promising bacterial fertilizers to improve plant growth under adverse environment.For ecological remediation of coastal wetlands,it was necessary to investigate the effect and interaction of endophytes on halophytes under saline-alkali stress.In this study,an endophytic bacterium strain HK1 isolated from halophytes was selected to infect Suaeda glauca under pH(7 and 8)and salinity gradient(150,300 and 450mmolL^(-1)).Strain HK1 was identified as Pantoea ananatis and it had ability to fix nitrogen,dissolve inorganic phosphorus and produce indole-3-aceticacid(IAA).The results showed that strain HK1 could promote the growth of S.glauca seedings when the salinity was less than 300mmolL^(-1),in view of longer shoot length and heavier fresh weight.The infected plants could produce more proline to decrease the permeability of cells,which content increased by 26.2%–61.1%compared to the non-infected group.Moreover,the oxidative stress of infected plants was relieved with the malondialdehyde(MDA)content decreased by 16.8%–32.9%,and the peroxidase(POD)activity and catalase(CAT)activity increased by 100%–500%and 6.2%–71.4%,respectively.Statistical analysis revealed that increasing proline content and enhancing CAT and POD activities were the main pathways to alleviate saline-alkali stress by strain HK1 infection,and the latter might be more important.This study illustrated that endophytic bacteria could promote the growth of halophytes by regulation of osmotic substances and strengthening antioxidant activities.This finding would be helpful for the bioremediation of coastal soil.

Analysis of oxidative stress and antioxidative potential in premature ovarian insufficiency

BACKGROUND Premature ovarian insufficiency(POI)is characterized by an early decline in ovarian function,inducing secondary amenorrhea.While the cause of POI has not yet been identified,the function of mitochondria in the ovaries and the cytotoxicity associated with reactive oxygen species(ROS)have been implicated in follicle pool depletion and a decline in follicle quality.Recently developed tests have enabled easy measurement of diacron-reactive oxygen metabolites(d-ROMs)and biological antioxidant potential(BAP).The combination of these two tests is used to comprehensively assess oxidative stress in the blood.AIM To comprehensively assess the oxidative stress of d-ROMs and BAP in POI.METHODS Participants were classified into two groups:A POI group of 11 women aged<40 years examined between January 2021 and June 2022 with a history of secondary amenorrhea for at least 4 mo in our hospital and an FSH value of≥40 mIU/mL;and a control group of healthy women of the same age with normal ovarian function in our hospital.Plasma d-ROMs and BAP were measured in both these groups underwent.Differences between groups were assessed using the t-test.RESULTS The mean age and mean body mass index(BMI)were 35.8±3.0 years and 20.1±1.9 kg/m2 in the control group and 35.8±2.7 years and 19.4±2.5 kg/m2 in the POI group,respectively.The mean gravidity and parity in control and POI groups were 0.6±0.7 and 0.4±0.5 and 0.6±0.9 and 0.3±0.5,respectively.The two groups did not differ significantly in terms of mean age,BMI,gravidity,or parity.The d-ROMs level was significantly higher in the POI group than in the control group(478.2±58.7 vs 341.1±35.1 U.CARR;P<0.001);however,the BAP level did not significantly differ between the two groups(2078.5±157.4 vs 2029.0±186.4μmol/L).The oxidase stress index(d-ROMs/BAP×100)was significantly higher in the POI group than in the control group(23.7±3.3 vs 16.5±2.1;P<0.001).CONCLUSION Oxidative stress was significantly greater in the POI group than in the control group,suggesting oxidative stress as a factor that can serve as a POI biomarker.

Cd and Hg Mediated Oxidative Stress,Antioxidative Metabolism and Molecular Changes in Soybean(Glycine max L.)

Cadmium(Cd)and Mercury(Hg)is among the heavy metals most hazardous for plant and human health.Known to induce oxidative stress in plants and disbalance equilibrium in the antioxidant defence system,these metals alter plant growth and cause damage at the cellular and molecular levels.Soybean is an important oilseed crop that is raised in soils often contaminated by Cd and Hg.The comparative studies on the deleterious effect of Cd and Hg and the defence system of antioxidants were not studied earlier in soybean plant.In this study,soybean plants were exposed to Cd(100μM CdCl_(2))and Hg(100μM HgCl_(2))and studied for physiological,biochemical and molecular responses.Both Cd and Hg treatment increased the magnitude of oxidative stress.Activities of antioxidant enzymes were significantly upregulated in response to Cd and Hg stress.Quantitative and qualitative assessment of isolated RNA showed significant differences in RNA under stress.Integrity values of RNA confirmed alterations.Transcript level of the Actin gene,involved in the morphogenesis of plants and also used as referenced gene in expression studies was analyzed using qRT-PCR just to check its stability and response under heavy metal stress.Results showed significant upregulation of the gene in the presence of Cd.It can be concluded that both Cd and Hg caused oxidative damage to plants,and adversely affected the quality of RNA.However,soybean tried to limit the adverse impacts of Cd and Hg stress by elevating the antioxidant system and upregulating Actin gene.

Changes of Proline Content,Activity,and Active Isoforms of Antioxidative Enzymes in Two Alfalfa Cultivars Under Salt Stress

The plants of two elfalfa （Medicago sativa L.） cultivars differing in salt tolerance were subjected to three salt treatments, 70, 140, and 210 mM NaCl for 7 days. Root, shoot, and leaf growths were inhibited by increased salt treatments in both cultivars, and at 140 and 210 mM salt treatments, Zhongmu 1 had significantly higher root, shoot, and leaf dry weights per plant than Deft. The malondialdehyde （MDA） accumulation in Deft was considerably greater than in Zhongmu 1, indicating a higher degree of lipid peroxidation at 140 and 210 mM salt treatments. The changes in the activity and active isoforms of antioxidant enzymes such as superoxide dismutase （SOD, EC 1.15.1.1）, catalase （CAT, EC 1.11.1.6）, peroxidase （POD, EC 1.11.1.7）, and ascorbate peroxidase （APOX, EC 1.11,1.11）, accumulation of free proline, and rate of lipid peroxidation in leaves of two alfalfa cultivars were also investigated. After stress, the activity and active isoforms of antioxidative enzymes were altered and the extent of alteration varied between the cultivar Deft and Zhongmu 1. The proline accumulation in Deft was considerably greater than in Zhongmu 1 at 210 mM salt treatment. This indicated that proline accumulation may be the result, instead of the cause, of salt tolerance.

Changes of Antioxidative Enzymes and Lipid Peroxidation in Leaves and Roots of Waterlogging-Tolerant and Waterlogging-Sensitive Maize Genotypes at Seedling Stage

To better understand the physiological and biochemical mechanisms of waterlogging tolerance, waterlogging effects on lipid peroxidation and the activity of antioxidative enzymes were investigated in leaves and roots of two maize genotypes, HZ32 （waterlogging-tolerant） and K12 （waterlogging-sensitive）. Potted maize plants were waterlogged at the second leaf stage under glasshouse conditions. Leaves and roots were harvested 1 d before and 2, 4, 6, 8 and 10 d after the start of waterlogging treatment. Through comparing the activities of superoxide dismutase （SOD）, ascorbate peroxidase （APX）, glutathione reductase （GR）, catalase （CAT） and guaiacol peroxidase （POD） between waterlogging-tolerant and waterloggingsensitive genotype, we deduced that CAT was the most important H2O2 scavenging enzyme in leaves, while APX seemed to play a key role in roots. POD, APX, GR and CAT activities in conjunction with SOD seem to play an essential protective role in the O2^- and H2O2 scavenging process. Lipid peroxidation was enhanced significantly only in K12 （P 〈 0.001） and there was no difference （P 〉 0.05） in HZ32 up to 6 d after waterlogging stress. These results indicated that oxidative stress may play an important role in waterlogging-stressed maize plants and that the greater protection of HZ32 leaves and roots from waterlogging-induced oxidative damage results, at least in part, through the maintenance of increased antioxidant enzyme activity.

Effects of dietary graded levels of cinnamon essential oil and its combination with bamboo leaf flavonoid on immune function, antioxidative ability and intestinal microbiota of broilers

Cinnamon essential oil(CEO)and its combination with bamboo leaf flavonoid(BLF)have been shown to exhibit an additive antibacterial effect in vitro,but their functions in broilers were not clear.An experiment was conducted to investigate the effects of dietary graded levels of CEO and its combination with BLF on the growth performance,immune responses,antioxidative ability,and intestinal morphology and microbiota of broilers fed a corn-soybean meal basal diet.A total of 576 1-d-old Arbor Acres commercial male broilers were randomly allotted to 9 treatments with 8 replicates of 8 birds each in a completely randomized design.Birds were fed on a basal corn-soybean meal diet(control,without plant extracts and antibiotics),or the basal diet supplemented with 50 mg of aureomycin kg^-1,50,100,200,400,or 800 mg of CEO kg^-1,a combination of 100 mg of CEO and 16.7 mg of BLF kg^-1,or a combination of 200 mg of CEO kg^-1 and 33.3 mg of BLF kg^-1 for 42 d.Dietary treatment affected(P<0.05)the serum immune globulin M(IgM)contents on d 42,liver malondialdehyde(MDA)contents on d 21,duodenal crypt depth on d 42,relative abundance of Lactobacillus in the cecal contents on d 21,and relative abundances of Escherichia coli and Bifidobacterium in the cecal contents on d 42,but had no effect(P>0.16)on all other measured indices.The addition of 400 mg of CEO kg^-1 or a combination of 200 mg CEO kg^-1 and 33.3 mg BLF kg^-1 increased(P<0.02)serum IgM contents on d 42.Dietary supplementation with 100 or 200 mg CEO kg^-1,or 50 mg aureomycin kg^-1 decreased(P<0.003)liver MDA contents on d 21.In addition,the supplement of 100 mg CEO kg^-1 increased(P<0.002)the Lactobacillus relative abundance in caecum on d 21 and Bifidobacterium relative abundance in caecum on d 42,and decreased(P<0.0001)E.coli relative abundance in caecum on d 42.The results indicated that dietary supplementation with CEO,an alternative to aureomycin,improved the immune status,antioxidantative ability and cecal microbiota of broilers,and dietary supplementation with the combinations of CEO and BLF did not exhibit further effects.Dietary supplementation with 100 mg CEO kg^-1 is beneficial for broilers fed a corn-soybean meal basal diet.

Ultrasonic Extraction of Polysaccharides from Laminaria japonica and Their Antioxidative and Glycosidase Inhibitory Activities

In the present study, ultrasonic extraction technique （UET） is used to improve the yield of polysaccharides from Lami- naria japonica （LJPs）. And their antioxidative as well as glycosidase inhibitory activities are investigated. Box-Behnken design （BBD） combined with response surface methodology （RSM） is applied to optimize ultrasonic extraction for polysaccharides. The optimized conditions are obtained as extraction time at 54 min, ultrasonic power at 1050 W, extraction temperature at 80℃ and ratio of material to solvent at 1：50 （g mL-1）. Under these optimal ultrasonic extraction conditions, an actual experimental yield （5.75% ＋ 0.3%） is close to the predicted result （5.67%） with no significant difference （P〉0.05）. Vitro antioxidative and glycosidase inhibitory activities tests indicate that the crude polysaccharides （LJP） and two major ethanol precipitated fractions （LJP1 and LJP2） are in a concentration-dependent manner. LJP2 （30%-60% ethanol precipitated polysaccharides） possesses the strongest α-glucosidase in- hibitory activity and moderate scavenging activity against hydroxyl radicals （66.09% ±2.19%, 3.0 mg mL-l）. Also, the inhibitory activity against a-glucosidase （59.08% ± 3.79%, 5.0 mg mL-1） is close to that of acarbose （63.99% ± 3.27%, 5.0 mg mL-l）. LJP 1 （30% ethanol precipitated polysaccharides） exhibits the strongest scavenging activity against hydroxyl radicals （99.80%q-0.00%, 3.0mg mL-1） and moderate a-glucosidase inhibitory activity （47.76%± 1.92%, 5.0 mgmL-1）. LJP shows the most remarkable DPPH scav- enging activity （66.20%±0.11%, 5.0mgmL-1） but weakest a-glucosidase inhibitory activity （37.77%±1.30%, 5.0mgmL-1）. How- ever, all these LJPs exert weak inhibitory effects against a-amylase. These results show that UET is an effective method for extract- ing bioactive polysaccharides from seaweed materials. LJP 1 and LJP2 can be developed as a potential ingredient in hypoglycemic agents or functional food for the management of diabetes. This study provides scientific evidence and advances in the preparation technology and a hypoglycemic activities evaluation method for seaweed polysaccharides, especially glycosidase inhibition in com- bination with an antioxidative activity evaluation method.

Comparison of photosynthesis and antioxidative protection in Sophora moorcroftiana and Caragana maximovicziana under water stress

This study aims to investigate the protective roles of photosynthetic characteristics and antioxidative systems in the desiccation tolerance of Sophora moorcroftiana and Caragana maximovicziana as they adapt to arid environments. A variety of physiological and biochemical parameters in the leaves of two Leguminosae species were monitored for 1, 7, 14, 21 and 28 d of drought stress. Soil water content decreased from 38.58% to 7.33% after exposure to 28 d of water stress. The photosynthetic carbon-assimilation rates of the two Leguminosae plants decreased for non-stomatal limitation with processing water stress. The malondialdehyde content and cell membrane relative conductivity of the two species increased significantly from 1 to 21 d and then decreased. S. moorcroftiana showed higher superoxide dismutase and peroxidase activities than C. maximovicziana during the 28 d treatment period. However, the catalase activities and proline content of C. maximovicziana were higher than those of S. moorcroftiana before the water stress treatment reached 21 d. Nine physiological and biochemical parameters were selected to comprehensively evaluate the two species＇ drought-resistance by the membership function values（MFV）. The mean MFV indicated that S. moorcroftiana has a relatively stronger drought defense capability than C. maximovicziana. S. moorcroftiana mainly uses carbon-assimilation rate and osmotic adjustment to combat water deficiency.

Effects of selenium source and level on growth performance, antioxidative ability and meat quality of broilers

This experiment was conducted to investigate the effects of selenium(Se) source and level on growth performance, carcass traits, antioxidative ability and meat quality of broilers. A total of 320 one-d-old Arbor Acres commercial broilers were randomly assigned to 1 of 5 treatments with 8 replicates in a completely randomized design involving a 2×2 factorial arrangement of treatments plus one Se-unsupplemented basal diet control for 42 d. The two Se sources were sodium selenite and Se yeast, and the two supplemental Se levels were 0.20 and 0.40 mg Se kg^–1. The results showed that broilers fed the Se-supplemented diets had higher(P<0.05) average daily gain and average daily feed intake from 22 to 42 d of age, eviscerated yield and abdominal fat percentages, Se concentrations and glutathione peroxidase(GSH-Px) activities in breast and thigh muscles on d 42, and lower(P<0.05) feed/gain from 1 to 21 and 22 to 42 d of age, mortality from 22 to 42 d of age and malondialdehyde(MDA) concentration in thigh muscle on d 42 than those fed the control diet. Broilers fed the diets supplemented with Se yeast had higher(P<0.05) p H value and lower(P<0.05) shear force in thigh muscle than those fed the diets supplemented with sodium selenite. Additionally, broilers fed the diets supplemented with 0.40 mg Se kg^–1 had lower(P<0.05) shear force in thigh muscle and higher(P<0.05) GSH-Px activities in breast and thigh muscles than those fed the diets supplemented with 0.20 mg Se kg^–1. Furthermore, broilers fed the diet supplemented with Se yeast at 0.40 mg Se kg^–1 had higher(P<0.05) Se concentrations in breast and thigh muscles than those fed the diet supplemented with Se yeast at 0.20 mg Se kg^–1, but no differences(P<0.05) were observed in these indices of broilers fed the diets supplemented with sodium selenite between 0.20 and 0.40 mg Se kg^–1. The results from the present study indicated that supplemental Se could increase the growth performance, muscle Se concentration and antioxidative ability of broilers;and the Se from Se yeast was more effective than the Se from sodium selenite in improving meat quality of broilers.

Photosynthetic Characteristics and Antioxidative Metabolism of Flag Leaves in Responses to Nitrogen Application During Grain Filling of Field-Grown Wheat

A two-factorial experiment was conducted with two wheat cultivars, SN1391 （large spike and large grain） and GC8901 （multiple spike and medium grain）, and two nitrogen （N） application rates （12 and 24 g N m^-2）, to investigate the responses of photosynthetic characteristics and antioxidative metabolism to nitrogen rates in flag leaves of field-grown wheat during grain filling. The results showed that the content of N and chlorophyll （Chl） in wheat flag leaves decreased after anthesis and the net photosynthetic rate （Pn）, effective quantum yield of PS Ⅱ （Фps n）, efficiency of excitation capture by open PS Ⅱ reaction centers （Fv′/Fm′）, and photochemical quenching coefficient （qp） began to decrease at 14 days after anthesis. However, the maximal efficiency of PS Ⅱ photochemistry （Fv/Fm） decreased slightly until the late period of senescence and the nonphotochemical quenching coefficient （NPQ） increased during flag leaves＇ senescence, As a result, a conflict came into being between absorption and utilization to light energy in flag leaves during senescence, which might accelerate the senescence of flag leaves. Compared with GC8901, the lower plant population of SN1391 during grain filling was helpful to maintain the higher content of photosynthetic pigment, activity of PS II, and Pn in flag leaves during senescence, The delayed decrease in antioxidative enzyme activity and the lower degree of membrane lipid peroxidation in the senescing leaves of SN1391 were beneficial to protect the photosynthetic apparatus, which lead to the prolonged duration of CO2 assimilation. With the increase of N application, the Chl content of SN1391 flag leaves and the efficiency of excitation captured by open PS Ⅱ centers increased. At the same time, the thermal dissipation in SN1391 flag leaves at high N （HN） treatment decreased and Фps Ⅱ improved greatly, which were favorable to the increase of Pn. The SOD, POD, CAT and APX activities in the flag leaves of SN1391 increased markedly at HN treatment, indicating that these enzymes could clean more active oxygen and decrease the degree of membrane lipid peroxidation. In this way, the ability of SN1391 to protect photosynthetic apparatus was improved with the increase of N. In the HN treatment, the decreased activity of PS Ⅱ and increased thermal dissipation resulted in the decline of Pn in flag leaves of GC8901. Meanwhile, the decreased antioxidative enzyme activities and the increased degree of membrane lipid peroxidation had indirect and unfavorable influences on CO2 assimilation. This implied that the conflict between absorption and utilization to energy in senescing leaves was an important reason which induced and accelerated the senescence of wheat leaves in the field. The photosynthetic characteristics and antioxidative metabolism of flag leaves during grain filling were markedly different among wheat cultivars. The effects of nitrogen rate on the photosynthetic and senescent characteristics of flag leaves also varied with wheat cultivars.

Effects of Soybean Isoflavones on In vitro Antioxidative Capacity of Satellite Cells of Porcine Skeletal Muscles

A synthetic isoflavone （ISO-S） or genistein was added in culture medium at different concentrations （0, 10, 20, 30, 40, and 80 p.mol L^-1） to investigate the effects of soybean isoflavones on antioxidative capacity of porcine skeletal muscle satellite cells. After 48 h incubation, the suspension was cryopreserved for the determination of superoxide dismutase （SOD）, catalase （CAT）, glutathione peroxidase （GSH-Px） activities, and malondialdehyde （MDA） content. The mRNA levels of SOD, CAT, and GSH-Px gene in cells were detected with Taqman fluorescent probe method. The results showed that the content of MDA and the activities and the mRNA levels of SOD of porcine skeletal muscle satellite cells were influenced by supplemented soybean isoflavone （P〈0.05） when adding 10-80 μmol L^-1 ISO-S or genistein in the medium. The MDA contents, SOD and CAT activities and their mRNA expression levels of porcine skeletal muscle cells responded quadratically （P〈 0.05） as the level of ISO-S or genistein increased. Pre-incubation of porcine skeletal muscle satellite cells with ISO-S or genistein at 10-40 pmol L-1 elevated the activities and the mRNA expression levels of SOD and CAT in cells concurrently and decreased the cellular content of MDA （P〈 0.05）. The results indicated that pre-incubation of ISO-S or genistein at 10- 40μmol L^-1 could improve the antioxidative capacity of porcine skeletal muscle satellite cells.

Microalgae(Chlorella vulgaris Beijerinck)alleviates drought stress of broccoli plants by improving nutrient uptake,secondary metabolites,and antioxidative defense system

Microalgae,such as Chlorella vulgaris Beijerinck(green algae),are beneficial microscopic organisms that may help plants to improve nutrient uptake,growth,and abiotic tolerance to stressors.The current study was performed to investigate the effectiveness of algae(Chlorella vulgaris Beijerinck)foliar applications[1%,3%,or 5%(v/v)]on mitigation of drought stress in broccoli plants subjected to water deficit at 25%of field capacity.The results showed that the broccoli plants grown under drought stress alone exhibited severe disturbance in growth with considerable reductions in the shoot length,and fresh and dry weights,leaf area,relative water content,leaf water potential,and photosynthetic pigment contents and elevated levels of the lipid peroxidation product malondialdehyde in the leaves.Additionally,the foliar application of microalgae mitigated the detrimental effects of drought,leading to better growth performance(increase of 9%–132%)when compared with the drought-stressed plants that had not received an application of microalgae.Microalgae-mediated beneficial effects were particularly evident in the enhancement of the photosynthetic pigment contents,including chlorophyll-a(6%–60%),chlorophyll-b(19%–55%),and total carotenoids(26%–114%).Exogenous microalgae also contributed to the reduction of membrane damage,as proven by significantly decreased levels of malondialdehyde(10%–39%)in the leaves of the broccoli plants exposed to drought stress.The application of microalgae increased the total flavonoid and phenolic contents,and nutrition uptake.Furthermore,the activities of enzymatic antioxidants like ascorbate peroxidase,catalase,glutathione reductase,and superoxide dismutase increased in response to mediation,resulting in significant alleviation of drought-induced oxidative damage.The most effective application concentration of microalgae was determined as 5%.Overall investigations revealed that the foliar application of microalgae could be recommended as a sustainable strategy to improve the defense system of drought-stressed broccoli plants.

Phenolic Constituents with Antioxidative,Tyrosinase Inhibitory and Anti‑aging Activities from Dendrobium loddigesii Rolfe

Aqueous ethanol extracts of powdered stems of Dendrobium loddigesii afforded three new phenolics including threo-7-Oethyl-9-O-(4-hydroxyphenyl)propionyl-guaiacylglycerol(1),(R)-4,5,4ʹ-trihydroxy-3,3ʹ,α-trimethoxybibenzyl(2)and(S)-5,5′,7-trihydroxy-3′,4′-dimethoxyflavanone(3),together with eleven known analogues.Their structures were determined by extensive spectroscopic analysis.To identify natural antioxidants,whitening,and anti-aging agents,the abilities of these phenolics were assessed to scavenge the 1,2-diphenyl-2-picrylhydrazyl(DPPH)radical,their abilities to inhibit tyrosinase production,and their abilities to stimulate collagen production by human dermal fibroblasts-adult(HDFa)assay.It was found that compounds 1,4-8,13 and 14 exhibited significant DPPH radical scavenging activities,compound 10 exhibited tyrosinase inhibitory activity(IC_(50)37.904μg/mL),and compound 9 showed significant collagen production with an EC_(50)value of 3.182μg/mL.These results suggest that phenolic constituents from D.loddigesii may be candidate antioxidants,skin-whitening and/or anti-aging agents.

Antioxidative effect of folate-modified chitosan nanoparticles

Objective:To evaluate the potency of carboxymethyl chitosan-2,2' ethylenedioxy bisethylamine-folate(CMC-EDBE-FA) on tissue injury,antioxidant status and glutathione system in tissue mitochondria and serum against nicotine-induced oxidative stress in mice.Methods: CMC-EDBE-FA was prepared on basis of carboxymethyl chitosan tagged with folic acid by covalently linkage through 2,2' ethylenedioxy bis-ethylamine.Animals were divided into four groups,i.e.,control,nicotine(1 mg/kg bw/day),CMC-EDBE-FA(1 mg/kg bw/day) and nicotine(1 mg/kg bw/day) and CMC-EDBE-FA(1 mg/kg bw/day) for 7 days.Levels of lipid peroxidation, oxidized glutathione level,antioxidant enzyme status and DNA damage were observed and compared.Results:The significantly increase of lipid peroxidation,oxidized glutathione levels and DNA damage was observed in nicotine treated group as compared with control group;those were significantly reduced in CMC-EDBE-FA supplemented group.Moreover,significantly reduced antioxidant status in nicotine treated group was effectively ameliorated by the supplementation of CMC-EDBE-FA.Only CMC-EDBE-FA treated groups showed no significant change as compared with control group;rather than it repairs the tissue damage of nicotine treated group.Conclusions:These findings suggest that CMC-EDBE-FA is non-toxic and ameliorates nicotine-induced toxicity.

Isolation,purification,structural characteristic and antioxidative property of polysaccharides from A.cepa L.var.agrogatum Don

Allium cepa L.var.agrogatum Don(ALAP)is commonly consumed in China as well as other regions and has various beneficial health effects.A novel acidic polysaccharide(named ALAP-21)was obtained from ALAP by ultrasonic and microwave-assisted extraction and purification using DEAE-52 anion exchange and Sephadex G-100 columns.The monosaccharide composition,structural and antioxidative properties of ALAP-21 were investigated by GC–MS chromatography,FT-IR and NMR spectroscopies and three antioxidative activity tests in vitro.The results showed that ALAP-21 was a heteropolysaccharide composed of glucose,galacturonic acid,mannose,galactose,arabinose,rhamnose,xylose,fructose and glucuronic acid with a relative molar ratio of 26.282:27.546:11.400:4.781:2.467:2.445:3.622:1.106:1.753,owning(1→4)-β-d-Glcp,(1→4)-β-d-GalAp6Me3OA,(1→4)-β-d-Galp6OMe,(1→2)-β-l-Rhap,(1→4)-β-d-Manp glycosidic linkages.(1→4)-β-d-Glcp and(1→4)-β-d-GalAp6Me3OA residues might be the main components of the sugar chain backbone of ALAP-21.Furthermore,ALAP-21 exhibited high potential for DPPH radicals(82.02%),hydroxyl radicals(53.33%)and superoxide anion radicals(50.28%).These results provide a reference for further research and rational development of ALAP polysaccharides.

Grafting Enhances Copper Tolerance of Cucumber Through Regulating Nutrient Uptake and Antioxidative System

An experiment was carried out to determine plant growth, mineral uptake, lipid peroxidation, antioxidative enzymes, and antioxidant of cucumber plants （Cucumis sativus L. cv. Xintaimici） under copper stress, either ungrafted or grafted onto the rootstock （Cucurbitaficifolia）. Excess Cu inhibited growth, photosynthesis, and pigment synthesis of grafted and ungrafted cucumber seedlings and significantly increased accumulation of Cu in roots besides reducing mineral uptake. Cu concentration in roots of grafted cucumber plants was significantly higher than that of ungrafted plants and obviously lower in leaves. The accumulation of reactive oxygen species （ROS） significantly increased in cucumber leaves under Cu stress and resulted in lipid peroxidation, and the levels of ROS and lipid peroxidation were greatly decreased by grafting. Activities of protective enzymes （superoxide dismutase, SOD; peroxidase, POD; catalase, CAT; ascorbate peroxidase, APX; dehydroascorbate reductase, DHAR; glutathione reductase, GR） and the contents of ascorbate and glutathione in leaves of grafted plants were significantly higher than those of ungrafted plants under Cu stress. Better performance of grafted cucumber plants were attributed to the higher ability of Cu accumulation in their roots, better nutrient status, and the effective scavenging system of ROS.

Synthesis, Characterization and Antioxidative Activity of Lanthanide Complexes with Genistein

Six genistein lanthanide complexes, LnL_2 (OAc)·nH_2O [Ln=La(Ⅲ), Sm(Ⅲ), Eu(Ⅲ), Gd(Ⅲ), (Tb(Ⅲ),) Dy(Ⅲ); L=genistein; n=4, 7, 8] were synthesized and characterized on the basis of elemental analyses, IR, (()~1H) NMR spectra and molar conductivity. The scavenging activity of genistein and five lanthanides complexes on the hydroxyl free radicals (OH·) was also investigated by spectrophotometric methods. The results show that the scavenging activity of the complexes is better than that of the ligand and their scavenging ability can be assembled in the following order: Sm>La>Dy>Eu>Tb>L.

In vitro larvicidal potential against Anopheles stephensi and antioxidative enzyme activities of Ginkgo biloba,Stevia rebaudiana and Parthenium hysterophorous

Objective:To investigate in vitro larvicidal and antioxidant enzymes potential of the medicinal plants Ginkgo biloba（G.biloba）,Stevia rebaudiana（S.rebaudiana） and Parthenium hysterophorous（P.hysterophorous） against Anopheles stephensi（An.stephensi） 4th instars larvae. Methods:For evaluation of larvicidal potential,the ethanolic,methanolic and dichloromethane leaves extracts of three different plants were used in dose-dependent experiments in two media, while the antioxidant enzymes activities were investigated using four different methods viz., superoxide dismutase,peroxidase,ascorbate and catalase.Results:An.stephensi has developed resistance to various synthetic insecticides,making its control increasingly difficult.The comparative performance of ethanolic extracts（65%-90%） was found better than the methanolic extract（70%-87%） and dichloromethane extract（60%-70%）.Among the three plants extracts tested in two media,S.rebaudiana exhibited higher larvicidal activity with LC50（24 h） in methanolic extract than P.hysterophorous and G.biloba.G.biloba and P.hysterophorous exhibited the strongest antioxidative enzymes activity and S.rebaudiana were less active and no significant difference was observed.Conclusions:These three plants exhibit larvicidal potential and can be further used for vector control alternative to synthetic insecticide due to eco-friendly and diseases control,furthermore these plant species have potent antioxidative enzyme activities, therefore,making them strong natural candidate particularly for diseases which are caused due to free radicals.