The effects of plasticizers,antioxidants and burning rate modifiers on the aging performance of the composite solid propellant based on hydroxyl-terminated polybutadiene(HTPB)/hexamethylene diisocyanate(HMDI)were expl...The effects of plasticizers,antioxidants and burning rate modifiers on the aging performance of the composite solid propellant based on hydroxyl-terminated polybutadiene(HTPB)/hexamethylene diisocyanate(HMDI)were explored by apply-ing an accelerated aging program for 90 day at 70 ℃. The HTPB propellant matrix with the diisooctyl sebacate(DOS)as plasti-cizers and diisooctyl azelate(DOZ), antioxidants as N,N ′-Diphenyl-p-phenylenediamine(AO) and 2,2′-methylenebis(4-methyl-6-tert-butylphenol)(cyanox 2246)and burning rate modifiers as barium ferrite(BF),copper chromites(CC)and fer-ric oxide(FO)were varied. Results show that sample(S1)which based on DOS decreases the stress value and increases the strain value which considered to be an excellent start for aging program. Sample(S3)containing AO presents the higher resis-tance to oxidation showing the better performance that reflects on increasing the shelf life of the composite solid propellant mo-tor. Sample(S5)which based on BF enhances the ballistic performance among over the other tested two samples. The accelerat-ed aging program allowed us to estimate the motor in-service lifetime.展开更多
In this paper a method for simultaneous determination of 6 antioxidants (PG,TBHQ,BHA,OG,DG and NDGA) in animal feed by HPLC-MS/MS was described.The samples were extracted by acetonitrile and cleaned up with auto solid...In this paper a method for simultaneous determination of 6 antioxidants (PG,TBHQ,BHA,OG,DG and NDGA) in animal feed by HPLC-MS/MS was described.The samples were extracted by acetonitrile and cleaned up with auto solid phase extraction.The samples were separated by HPLC with a C8 column.The electrospray (ESI) negative mode detected by MRM is used for MS/MS.The detection limits were 2 mg/kg,recoveries and RSDs were 84%-106% and 3.0%-9.0% at this concentration respectively.The method was highly efficient and sensitive,stable and precise.展开更多
The objective of this research was to assess the potential of phosphatidylcholineencapsulated resveratrol as a cosmetic ingredient.The hydrogen peroxide(H_(2)O_(2))and ultraviolet A(UVA)induced human skin fibroblasts(...The objective of this research was to assess the potential of phosphatidylcholineencapsulated resveratrol as a cosmetic ingredient.The hydrogen peroxide(H_(2)O_(2))and ultraviolet A(UVA)induced human skin fibroblasts(HSF)models of skin damage were established to compare the antioxidant and anti-wrinkle properties between phosphatidylcholine-encapsulated resveratrol and unencapsulated resveratrol.The findings reveal that encapsulating resveratrol with phosphatidylcholine not only enhances skin absorption but also significantly improves its antioxidant capabilities.In the H2O2-induced HSF injury model,phosphatidylcholine-encapsulated resveratrol demonstrates a superior ability to neutralize reactive oxygen species(ROS)generated by H2O2 compared to the resveratrol group.Further analysis indicates that this enhanced functionality is associated with increased enzymatic activities of superoxide dismutase(SOD),glutathione peroxidase(GSH-Px)and catalase(CAT)when treated with phosphatidylcholine-encapsulated resveratrol.Additionally,in UVA-irradiated HSF cells,phosphatidylcholine-encapsulated resveratrol effectively reduces the levels of matrix metalloproteinases-1 and-3(MMP-1 and MMP-3)and increased the contents of CollagenⅠand CollagenⅢ(Col-1 and Col-3),demonstrating significant anti-wrinkle effects.These findings provide critical evaluation criteria and application references for enhancing cosmetic ingredients through phosphatidylcholine encapsulation,thereby advancing skincare formulations.展开更多
In this work, Staphylococcus epidermidis (S. epidermidis) was used to prepare the fermentation broths with antioxidant activity. Through the optimization of the carbon source, three kinds of S. epidermidis fermentatio...In this work, Staphylococcus epidermidis (S. epidermidis) was used to prepare the fermentation broths with antioxidant activity. Through the optimization of the carbon source, three kinds of S. epidermidis fermentation broth were obtained and designated as SFB, Gly-SFB, and Glu-SFB, which were cultivated in beef protein medium and the beef protein medium supplemented with glycerol or glucose, respectively. The differences in antioxidant efficacy of SFB, Gly-SFB and Glu-SFB were investigated by evaluating intracellular ROS fluorescence intensity, SOD enzyme activity and MDA concentration. Gly-SFB and Glu-SFB exhibited a greater capacity to eliminate ROS as compared to that of SFB. The intracellular SOD enzyme activity increased as the concentrations of SFB and Gly-SFB increased. Nevertheless, the intracellular SOD enzyme activity was the highest after the treatment with Glu-SFB at the low concentrations. The intracellular MDA content reached a lower value after the treatment with Gly-SFB and Glu-SFB at lower concentrations, which was opposite to the case after the treatment with SFB. WB indicated that the S. epidermidis fermentation broth regulated the expression of relevant proteins in the Nrf2-Keap1 signaling pathway to exhibit the antioxidant effects. This indicates that the S. epidermidis fermentation broth promotes the expression of relevant proteins in the Nrf2-Keap1 signaling pathway, consequently, antioxidant benefits were exerted. The fermentation broth that were prepared by incorporating glycerol or glucose into the culture medium can augment their antioxidant activity.展开更多
This study aimed to investigate the effects of dietary guanidinoacetic acid on growth performance,meat quality,antioxidant activity,and antioxidant-related gene expression in ducks.Total 48042-day-old female ducks wer...This study aimed to investigate the effects of dietary guanidinoacetic acid on growth performance,meat quality,antioxidant activity,and antioxidant-related gene expression in ducks.Total 48042-day-old female ducks were randomly divided into four groups with six replicates and 20 ducks per replicate and fed the basal diet to the control group.The experimental groups were fed the basal diet with 400,600 and 800 mg·kg^(-1) guanidinoacetic acid,respectively.The trial lasted 48 days.Compared with the control group,(1)the body weight at 90 days and average daily gain were increased(P<0.05),the feed conservation ratio was decreased(P<0.05);(2)the dressing percentage and breast muscle percentage were increased(P<0.05);(3)the total amino acid content,polyunsaturated fatty acids to monounsaturated fatty acids ratio were increased(P<0.05)in breast and thigh muscles;(4)activities of superoxide dismutase,catalase and glutathione peroxidase enzyme were increased(P<0.05)in thigh muscles;(5)the relative expressions of superoxide dismutase 1,glutathione peroxidase 1,and catalase were significantly increased(P<0.05)in the liver.In this study,the optimum dosage of 600 mg·kg^(-1) guanidinoacetic acid improved the growth performance,meat quality,antioxidant activity,and antioxidant-related gene expression in ducks.展开更多
Lead(Pb)and zinc(Zn)are widely recognized as common environmental contaminants,contributing to soil degradation and posing risks to environmental health.Combining functional carbon-based materials with microorganisms ...Lead(Pb)and zinc(Zn)are widely recognized as common environmental contaminants,contributing to soil degradation and posing risks to environmental health.Combining functional carbon-based materials with microorganisms has been considered as an effective and environmentally friendly strategy for remediating Pb/Zn-contaminated soil.However,there is still a lack of understanding the connection between heavy metal immobilization and plant responses,which hampers practical applications.Here,a 90-day pot experiment was conducted to investigate the integrated effects of biochar(WS700)and microorganisms including inorganic phosphate-solubilizing bacteria(IPSB)and sulfate reducing bacteria(SRB)on Pb and Zn synchronous immobilization and the physiological responses of Brassica rapa var.chinensis(Brassica).Compared with CK,bacteria-loaded biochar treatment declined the exchangeable Pb and Zn fraction by 94.69%−98.37%and 94.55%−99.52%,while increasing the residual state Pb and Zn by 75.50%−208.58%and 96.71%−110.85%,respectively.Three amendments enhanced Brassica growth by improving total chlorophyll content and superoxide dismutase(SOD)and peroxidase(POD)activities.The bacteria-loaded biochar treatment effectively regulated stomatal conductance and reduced intercellular CO_(2) concentration.Moreover,compared with CK,three amendments reduced MDA content by 28.84%,28.30%and 41.60%,respectively,under the high concentration of Pb and Zn.The findings demonstrated the significant role of bacterial-biochar consortia in immobilizing Pb and Zn and mitigating Pb and Zn-induced stress in plants by regulating photosynthetic characteristics and antioxidant enzyme activities.展开更多
Bone protein hydrolysates were prepared by limited alcalase hydrolysis （5 h）. The hydrolysates were formulated （0-3%, w/w） into pork patties to determine the antioxidant efficacy. 0.02% BHA （butylated hydroxyanis...Bone protein hydrolysates were prepared by limited alcalase hydrolysis （5 h）. The hydrolysates were formulated （0-3%, w/w） into pork patties to determine the antioxidant efficacy. 0.02% BHA （butylated hydroxyanisole） was used as a positive control. Lipid oxidation in patties during storage was analyzed by measuring the TBARS and protein carbonyl content. The results showed that bone protein hydrolysates possessed significant antioxidant activity, and antioxidant activity increased with the increasing hydrolysates concentration. Sensory evaluation indicated that bone protein hydrolysates improved the color and decreased lipid oxidation flavor of pork patties. The 2% bone hydrolysates possessed the highest antioxidant activity and better sensory quality, and its effect was closed to 0.02% BHA.展开更多
Gelatin extracted from deer bone was hydrolyzed for 3.5-120 min. The degree of hydrolysis was higher from Alcalasehydrolyzed gelatin than that from neutral proteinase-hydrolyzed gelatin. Alcalase-hydrolyzed gelatin ex...Gelatin extracted from deer bone was hydrolyzed for 3.5-120 min. The degree of hydrolysis was higher from Alcalasehydrolyzed gelatin than that from neutral proteinase-hydrolyzed gelatin. Alcalase-hydrolyzed gelatin exhibited a stronger antioxidant activity than that of neutral proteinase-hydrolyzed gelatin, Hydrolysates showed strong radical-scavenging ability and Fe^2＋-chelating activity, both of which were influenced by hydrolysis time. Although nonhydrolyzed gelatin displayed a certain antioxidative effect, it was far less than that of hydrolysates. The hydrolysates of deer bone gelatin can work as a radical stabilizer and metal ion chelator to inhibit lipid oxidation.展开更多
OBJECTIVE To observe the anti-aging effects of SOD mimic AEOL^(-1)0150 in antisenescence accelerated mouse resistant 1(SAMR1)strain.METHODS The lifespan of SAMR1 mice were observed by subcutaneous injection AEOL^(-1)0...OBJECTIVE To observe the anti-aging effects of SOD mimic AEOL^(-1)0150 in antisenescence accelerated mouse resistant 1(SAMR1)strain.METHODS The lifespan of SAMR1 mice were observed by subcutaneous injection AEOL^(-1)0150 2 mg·kg-1once a week.Morris water maze,new object recognition,nesting and forced swimming were used to observe the behavioral changes of animals.Lymphocyte subgroups and ROS were measured by Flow cytometry.The cytokines levels were determined by Luminex method.The number of DCX+neurons in brain tissue was observed by immunofluorescence.RESULTS The results showed that AEOL^(-1)0150 could prolong the mean lifespan of SAMR1 mice,but it had no obvious effect on maximal lifespan.What′s more,AEOL^(-1)0150 could significantly improve the spatial learning memory of aged mice,but it could not increase the number of DCX+neurons in the hypothalamic MBH and hippocampal DG regions.Then,we observed the effects of AEOL^(-1)0150 on peripheral blood lymphocyte subgroups and cytokines.We found that AEOL^(-1)0150significantly modulated the lymphocyte subgroups and cytokine release.Especially,AEOL^(-1)0150 can dose-dependently inhibit plasma levels of SASP related inflammatory cytokines TNF-αand IL^(-1)7.CONCLUSION The results indicate that AEOL^(-1)0150 has anti-aging effects,and the effects are closely related to modulating immunity and inhibiting SASP production.展开更多
Suaeda salsa an annual herb of Chenopodiaceae Suaeda well accepted as both a folk medicinal and food plant.In the current study,the extraction of total flavonoids from S.salsa and the in vitro antioxidant,hypoglycemic...Suaeda salsa an annual herb of Chenopodiaceae Suaeda well accepted as both a folk medicinal and food plant.In the current study,the extraction of total flavonoids from S.salsa and the in vitro antioxidant,hypoglycemic and hypolipidemic activities of the extracts were investigated.The total flavonoids was extracted by refluxing with ethanol and the selection and optimization of main experimental parameters were carried out using single factor experiments combined with central composite design-response surface methodology(CCD-RSM).The total flavonoids extracted from S.salsa were tested for hydroxyl and oxygen radical scavenging activity,and inhibitory activities againstα-amylase and lipase in vitro.Results revealed that the optimal conditions for the extraction of total flavonoids were as following:liquid-tosolid ratio,31.40:1;ethanol concentration,83.12%;reflux temperature,90℃,and reflux time,128.40 min.Under these optimized conditions,the predicted and actual values of total flavonoids yield were 0.896%and 0.932%,respectively.The in vitro antioxidant tests revealed that the total flavonoids could scavenge hydroxyl and oxygen radicals and showed inhibitory activity againstα-amylase and lipase.The optimal extraction conditions obtained in this experiment are simple to perform and have good reproducibility.The results have demonstrated that the total flavonoids from S.salsa can be used as a potential source of natural antioxidant,hypoglycemic and hypolipidemic ingredients,which provides new pharmacological basis for the development of S.salsa.展开更多
This study was to investigate the effects of cold stress on the contents of total antioxidant capacity （T-AOC） malondialdehyde （MDA） and superoxide dismutase （SOD） in duodenum, jejunum and ileum of chickens. A t...This study was to investigate the effects of cold stress on the contents of total antioxidant capacity （T-AOC） malondialdehyde （MDA） and superoxide dismutase （SOD） in duodenum, jejunum and ileum of chickens. A total of 80 15-dayold male chickens were treated by cold stress with the duration of the acute cold stress being 1, 3, 6, 12, and 24 h, and the chronic cold stress was 5, 10, and 20 days, respectively. Cold stress temperature was （12±1）℃. The chemical colorimetric method was used to detect the changes of the T-AOC, SOD activities and MDA contents. The results showed that compared with the corresponding control group, effects of acute cold stress on the T-AOC in duodenum, jejunum and ileum of chickens significantly （P〈0.05） increased firstly and then decreased. Under chronic cold stress, the T-AOC significantly （P〈0.05） decreased. Under acute cold stress and chronic cold stress, the MDA contents significantly （P〈0.05） increased in duodenum, jejunum and ileum of chickens. The effects of acute cold stress on the SOD activities in duodenum, jejunum and ileum of chickens significantly （P〈0.05） increased firstly and then decreased Under chronic cold stress the SOD activities significantly （P〈0.05） decreased in jejunum and ileum, but significantly （P〈0.05） decreased firstly and then increased in duodenum.展开更多
A reliable ultrasound-assisted extraction （UAE） method combined with HPLC-UV for quantification of eight active alkaloids in fruits of Macleaya cordata （Willd） R. Br. was developed. The optimization conditions of ...A reliable ultrasound-assisted extraction （UAE） method combined with HPLC-UV for quantification of eight active alkaloids in fruits of Macleaya cordata （Willd） R. Br. was developed. The optimization conditions of UAE were obtained by using Box-Behnken design of response surface methodology. Chromatography was carried out using a Kromasil C18 column by gradient elution with 0.1% phosphoric acid aqueous solution for HPLC-UV. All calibration curves showed good linear correlation coefficients （R^2〉0.999 6） and recoveries （from 97.3% to 104.9%） were acceptable. 1,1-diphenyl-2-picrylhydrazyl （DPPH） method was employed to test the antioxidant activity of the extract from the samples. The proposed method was successfully applied to quantifying eight components in nine samples of M.cordata, and significant variations of alkaloid contents and antioxidant aetivity of the samples from different habitats were demonstrated. It presents a powerful proof for the selection of the best sources to extract eight kinds of alkaloids.展开更多
The antioxidant activities and the total phenolic contents of the water and/or ethanol extracts of the nine selected culinary spices from China were systematically investigated. Both ethanol extracts and water extract...The antioxidant activities and the total phenolic contents of the water and/or ethanol extracts of the nine selected culinary spices from China were systematically investigated. Both ethanol extracts and water extracts had high ability of 1, 1-diphenyl-2-picrylhydrazyl（DPPH） radical scavenging, 2, 2＇-azinobis（3-ethylbenzthiazoline-6-sulphonic acid）（ABTS） radical scavenging and ferric reducing antioxidant power（FRAP）. The ethanol extract of Sichuan pepper showed the highest ability of DPPH radical scavenging. The extract with the highest ABTS radical scavenging effect was that of ethanol extract of cinnamon. Both ethanol and water extracts of cinnamon possessed the high ferric reducing antioxidant power（FRAP） with the values of 4 541.87 and 1 134.52 μmol of Fe（Ⅱ）/g. The extracts with high hydroxyl radical-mediated deoxyribose degradation were all the ethanol extracts as follows： cinnamon, bay leaf, Sichuan pepper, star anise and fennel. The extracts with high antioxidant activities also had the high contents of the phenols. The study indicated that these spices might be potentially be used as natural antioxidants in food.展开更多
Wheat germ protein hydrolysates were prepared by protease hydrolysis, ultrafiltration and dynamical adsorption of resin. The total amount of amino acids in 100 g wheat germ protein hydrolysates is 93.95 g. Wheat germ ...Wheat germ protein hydrolysates were prepared by protease hydrolysis, ultrafiltration and dynamical adsorption of resin. The total amount of amino acids in 100 g wheat germ protein hydrolysates is 93.95 g. Wheat germ protein hydrolysates are primarily composed of 4 fractions: 17.78% in the relative molecular mass range of 115631512, 17.50% in 1512842, 27.38% in 842372 and 30.65% in 37276, respectively. The antioxidant properties of wheat germ protein hydrolysates were evaluated by using different antioxidant tests in vitro. 1.20 g/L wheat germ protein hydrolysates exhibit 78.75% inhibition of peroxidation in linolei acid system; and 1.6g/L wheat germ protein hydrolysates show 81.11% scavenging effect on the 1,1-diphenyl-2-picrylhrazyl radical. The reducing power of 2.50 g/L wheat germ protein hydrolysates is 0.84. Furthermore, the scavenging activity of 0.60 g/L wheat germ protein hydrolysates against superoxide radical is 75.40%; 0.50 g/L wheat germ protein hydrolysates exhibit 63.35% chelating effect on ferrous ion. These antioxidant activities of wheat germ protein hydrolsates increase with the increase of its concentration. Experimental results suggest that wheat germ protein hydrolysate is a suitable natural antioxidant rich in nutrition and nontoxic.展开更多
The human plasma protein binding of water soluble flavonoids in the peels of five spices of citrus fruits was studied by ultrafiltration combined with HPLC.The flavonoids were extracted separately by hot and cold wate...The human plasma protein binding of water soluble flavonoids in the peels of five spices of citrus fruits was studied by ultrafiltration combined with HPLC.The flavonoids were extracted separately by hot and cold water,and higher total flavonoid contents were detected in the former extracts than the latter ones.All the extracts show significant scavenging abilities to both ABTS and DPPH free radicals,which indicates the health benefits of the water extracts of citrus fruits peels.For DPPH radical,the IC50values of hot extract follow as Navel orange(NO)≈Mandarin orange(MO)< Lemon(LE)< Lo tangerine(LO)< Pomelo(PO),while the rank is NO< PO<LE≈MO<LO for ABTS radical.The HPLC results reveal that the kinds and contents of the flavonoids detected in the extracts are different among the species.MO extract has the most neohesperidin dihydrochalcone of 118.76 μmol/L and quercetrin of 211.81 μmol/L of which are much more than the rest extracts.Pomelo extract has the most plentiful flavonoids of naringin with a concentration of 303.28 μmol/L.The high contents of myricetrin and dihydromyricetin which both are potent free radical scavengers may explain the highest free radical scavenging activity of the NO extract.The plasma binding rates decrease with the increasing concentrations of flavonoids,and the flavonoids having plenty hydroxyl groups on both A ring and B ring of the molecular skeleton have relative higher plasma binding rates.In addition,the plasma binding rates of flavonoids with saturated C3-C4 bond decrease significantly with the increasing concentrations.展开更多
To investigate the effects of allicin on chickens＇ lipid and antioxidant performance, Hy-laying hens＇ diets were replenished with 0 mg · kg-1, 50 mg · kg-1, 100 mg · kg-1, and 150 mg · kg-1 allic...To investigate the effects of allicin on chickens＇ lipid and antioxidant performance, Hy-laying hens＇ diets were replenished with 0 mg · kg-1, 50 mg · kg-1, 100 mg · kg-1, and 150 mg · kg-1 allicin for 42 days, respectively. The alanine aminotransferase（ALT）, aspartate aminotransferase（AST）, triglyceride（TG）, total cholesterol（TCHO）, high density lipoprotein（HDL）, and low density lipoprotein（LDL） levels were measured in chicken serum. Superoxide dismutase（SOD）, glutathione peroxidase（GSH-Px） activity and malondialdehyde（MDA） levels were measured in chicken serum and liver tissue homogenate. The results showed that the supplement dose of allicin tested did not significantly change the activity of ALT or AST（P〉0.05）; TG and CHOL levels decreased with the increase of allicin additive doses, and the difference between treatment groups and CG was significant（P〈0.05）, and there was the best effect with 100 mg · kg-1; allicin significantly reduced the content of MDA, and increased SOD and GSH-Px activities compared with CG（P〈0.05）, and 100 mg · kg-1 of allicin resulted in the strongest SOD and GSH-Px activity. The antioxidant function test results of liver tissue homogenate were consistant with that of serum. Our findings indicated that allicin could enhance antioxidant capacity and reduce blood lipid level in chickens and 100 mg · kg-1 was the optimal amount of allicin additives.展开更多
The fresh leaves and oven dried leaves from three varieties of black currant (Brodtrop,liangye,Risager)were analysed for the total contents of flavonoids by spectrophotometric methods in terms of rutin equivalent.In ...The fresh leaves and oven dried leaves from three varieties of black currant (Brodtrop,liangye,Risager)were analysed for the total contents of flavonoids by spectrophotometric methods in terms of rutin equivalent.In addition,antioxidant activities of different addition amounts of extracts of black currant (Brodtrop)leaves in lard were measured by the Oven-Storage Test,and compared with the synthetic antioxidants.The results showed the contents of the flavonoids were very rich in the leaves of three varieties from black currant.Among them the leaves of Brodtrop had the highest contents of flavonoids followed by liangye and Risager.The total contents of flavonoids in fresh leaves reach 231 70 mg/100 g,170 01 mg/100 g and 78 07 mg/100 g respectively.In the same circumstance the oven dried leaves were 397 82 mg/100 g,275 89 mg/100 g and 169 73 mg/100 g.The extracts of the leaves from Brodtrop exhibited strong antioxidant activities on lard,which increased with the addition amount of the flavonoid extracts.The antioxidant activities decreased in the order of 0 02% quercetin >0 02% BHT(butylated hydroxy toluene)>0 40% extracts>0 20% extracts>0 10% extracts>0 05% extracts>0 02% extracts>control.展开更多
This study investigated the chromium(Cr)detoxification mechanism-induced changes in growth and antioxidant defence enzyme activities in Chrysopogon zizanioides.Plant growth decreased by 36.8%and 45.0%in the shoots and...This study investigated the chromium(Cr)detoxification mechanism-induced changes in growth and antioxidant defence enzyme activities in Chrysopogon zizanioides.Plant growth decreased by 36.8%and 45.0%in the shoots and roots,respectively,in the 50 mg/L Cr treatment.Cr accumulation was higher in root(9807μg/g DW)than in shoots(8730μg/g DW).Photosynthetic pigments and malondialdehyde content increased up to the 30 mg/L Cr treatment,whereas they declined at higher doses.The activity of superoxide dismutase(SOD),catalase(CAT)and peroxidase(POX)were increased significantly with increasing of Cr dose but slightly declined at higher doses.Isozyme banding patterns revealed the expression of multiple bands for SOD,CAT and POX enzymes,and the band intensity decreased at high doses of Cr exposure.These results indicate that higher Cr doses increased the oxidative stress by over production of reactive oxygen species(ROS)in vetiver that had potential tolerance mechanism to Cr as evidenced by enhanced level of antioxidative enzymes,photosynthetic pigments,MDA contents.Therefore,vetiver has evolved a mechanism for detoxification and accumulates higher concentration of toxic Cr.This study provides a better understanding of how vetiver detoxifies Cr.展开更多
文摘The effects of plasticizers,antioxidants and burning rate modifiers on the aging performance of the composite solid propellant based on hydroxyl-terminated polybutadiene(HTPB)/hexamethylene diisocyanate(HMDI)were explored by apply-ing an accelerated aging program for 90 day at 70 ℃. The HTPB propellant matrix with the diisooctyl sebacate(DOS)as plasti-cizers and diisooctyl azelate(DOZ), antioxidants as N,N ′-Diphenyl-p-phenylenediamine(AO) and 2,2′-methylenebis(4-methyl-6-tert-butylphenol)(cyanox 2246)and burning rate modifiers as barium ferrite(BF),copper chromites(CC)and fer-ric oxide(FO)were varied. Results show that sample(S1)which based on DOS decreases the stress value and increases the strain value which considered to be an excellent start for aging program. Sample(S3)containing AO presents the higher resis-tance to oxidation showing the better performance that reflects on increasing the shelf life of the composite solid propellant mo-tor. Sample(S5)which based on BF enhances the ballistic performance among over the other tested two samples. The accelerat-ed aging program allowed us to estimate the motor in-service lifetime.
文摘In this paper a method for simultaneous determination of 6 antioxidants (PG,TBHQ,BHA,OG,DG and NDGA) in animal feed by HPLC-MS/MS was described.The samples were extracted by acetonitrile and cleaned up with auto solid phase extraction.The samples were separated by HPLC with a C8 column.The electrospray (ESI) negative mode detected by MRM is used for MS/MS.The detection limits were 2 mg/kg,recoveries and RSDs were 84%-106% and 3.0%-9.0% at this concentration respectively.The method was highly efficient and sensitive,stable and precise.
文摘The objective of this research was to assess the potential of phosphatidylcholineencapsulated resveratrol as a cosmetic ingredient.The hydrogen peroxide(H_(2)O_(2))and ultraviolet A(UVA)induced human skin fibroblasts(HSF)models of skin damage were established to compare the antioxidant and anti-wrinkle properties between phosphatidylcholine-encapsulated resveratrol and unencapsulated resveratrol.The findings reveal that encapsulating resveratrol with phosphatidylcholine not only enhances skin absorption but also significantly improves its antioxidant capabilities.In the H2O2-induced HSF injury model,phosphatidylcholine-encapsulated resveratrol demonstrates a superior ability to neutralize reactive oxygen species(ROS)generated by H2O2 compared to the resveratrol group.Further analysis indicates that this enhanced functionality is associated with increased enzymatic activities of superoxide dismutase(SOD),glutathione peroxidase(GSH-Px)and catalase(CAT)when treated with phosphatidylcholine-encapsulated resveratrol.Additionally,in UVA-irradiated HSF cells,phosphatidylcholine-encapsulated resveratrol effectively reduces the levels of matrix metalloproteinases-1 and-3(MMP-1 and MMP-3)and increased the contents of CollagenⅠand CollagenⅢ(Col-1 and Col-3),demonstrating significant anti-wrinkle effects.These findings provide critical evaluation criteria and application references for enhancing cosmetic ingredients through phosphatidylcholine encapsulation,thereby advancing skincare formulations.
文摘In this work, Staphylococcus epidermidis (S. epidermidis) was used to prepare the fermentation broths with antioxidant activity. Through the optimization of the carbon source, three kinds of S. epidermidis fermentation broth were obtained and designated as SFB, Gly-SFB, and Glu-SFB, which were cultivated in beef protein medium and the beef protein medium supplemented with glycerol or glucose, respectively. The differences in antioxidant efficacy of SFB, Gly-SFB and Glu-SFB were investigated by evaluating intracellular ROS fluorescence intensity, SOD enzyme activity and MDA concentration. Gly-SFB and Glu-SFB exhibited a greater capacity to eliminate ROS as compared to that of SFB. The intracellular SOD enzyme activity increased as the concentrations of SFB and Gly-SFB increased. Nevertheless, the intracellular SOD enzyme activity was the highest after the treatment with Glu-SFB at the low concentrations. The intracellular MDA content reached a lower value after the treatment with Gly-SFB and Glu-SFB at lower concentrations, which was opposite to the case after the treatment with SFB. WB indicated that the S. epidermidis fermentation broth regulated the expression of relevant proteins in the Nrf2-Keap1 signaling pathway to exhibit the antioxidant effects. This indicates that the S. epidermidis fermentation broth promotes the expression of relevant proteins in the Nrf2-Keap1 signaling pathway, consequently, antioxidant benefits were exerted. The fermentation broth that were prepared by incorporating glycerol or glucose into the culture medium can augment their antioxidant activity.
基金Supported by Hainan Provincial Natural Science Foundation of China(322MS134)。
文摘This study aimed to investigate the effects of dietary guanidinoacetic acid on growth performance,meat quality,antioxidant activity,and antioxidant-related gene expression in ducks.Total 48042-day-old female ducks were randomly divided into four groups with six replicates and 20 ducks per replicate and fed the basal diet to the control group.The experimental groups were fed the basal diet with 400,600 and 800 mg·kg^(-1) guanidinoacetic acid,respectively.The trial lasted 48 days.Compared with the control group,(1)the body weight at 90 days and average daily gain were increased(P<0.05),the feed conservation ratio was decreased(P<0.05);(2)the dressing percentage and breast muscle percentage were increased(P<0.05);(3)the total amino acid content,polyunsaturated fatty acids to monounsaturated fatty acids ratio were increased(P<0.05)in breast and thigh muscles;(4)activities of superoxide dismutase,catalase and glutathione peroxidase enzyme were increased(P<0.05)in thigh muscles;(5)the relative expressions of superoxide dismutase 1,glutathione peroxidase 1,and catalase were significantly increased(P<0.05)in the liver.In this study,the optimum dosage of 600 mg·kg^(-1) guanidinoacetic acid improved the growth performance,meat quality,antioxidant activity,and antioxidant-related gene expression in ducks.
基金Projects(2019NY-200,2020ZDLNY06-06,2020ZDLNY07-10)supported by the Key Research and Development Program of Shaanxi Province,ChinaProject(2019YFC1803604)supported by the National Key Research and Development Program of China。
文摘Lead(Pb)and zinc(Zn)are widely recognized as common environmental contaminants,contributing to soil degradation and posing risks to environmental health.Combining functional carbon-based materials with microorganisms has been considered as an effective and environmentally friendly strategy for remediating Pb/Zn-contaminated soil.However,there is still a lack of understanding the connection between heavy metal immobilization and plant responses,which hampers practical applications.Here,a 90-day pot experiment was conducted to investigate the integrated effects of biochar(WS700)and microorganisms including inorganic phosphate-solubilizing bacteria(IPSB)and sulfate reducing bacteria(SRB)on Pb and Zn synchronous immobilization and the physiological responses of Brassica rapa var.chinensis(Brassica).Compared with CK,bacteria-loaded biochar treatment declined the exchangeable Pb and Zn fraction by 94.69%−98.37%and 94.55%−99.52%,while increasing the residual state Pb and Zn by 75.50%−208.58%and 96.71%−110.85%,respectively.Three amendments enhanced Brassica growth by improving total chlorophyll content and superoxide dismutase(SOD)and peroxidase(POD)activities.The bacteria-loaded biochar treatment effectively regulated stomatal conductance and reduced intercellular CO_(2) concentration.Moreover,compared with CK,three amendments reduced MDA content by 28.84%,28.30%and 41.60%,respectively,under the high concentration of Pb and Zn.The findings demonstrated the significant role of bacterial-biochar consortia in immobilizing Pb and Zn and mitigating Pb and Zn-induced stress in plants by regulating photosynthetic characteristics and antioxidant enzyme activities.
基金Supported by Foundation of Science and Technology of 11th Five-Year Plan of Heilongjiang (GB06B403)
文摘Bone protein hydrolysates were prepared by limited alcalase hydrolysis （5 h）. The hydrolysates were formulated （0-3%, w/w） into pork patties to determine the antioxidant efficacy. 0.02% BHA （butylated hydroxyanisole） was used as a positive control. Lipid oxidation in patties during storage was analyzed by measuring the TBARS and protein carbonyl content. The results showed that bone protein hydrolysates possessed significant antioxidant activity, and antioxidant activity increased with the increasing hydrolysates concentration. Sensory evaluation indicated that bone protein hydrolysates improved the color and decreased lipid oxidation flavor of pork patties. The 2% bone hydrolysates possessed the highest antioxidant activity and better sensory quality, and its effect was closed to 0.02% BHA.
文摘Gelatin extracted from deer bone was hydrolyzed for 3.5-120 min. The degree of hydrolysis was higher from Alcalasehydrolyzed gelatin than that from neutral proteinase-hydrolyzed gelatin. Alcalase-hydrolyzed gelatin exhibited a stronger antioxidant activity than that of neutral proteinase-hydrolyzed gelatin, Hydrolysates showed strong radical-scavenging ability and Fe^2＋-chelating activity, both of which were influenced by hydrolysis time. Although nonhydrolyzed gelatin displayed a certain antioxidative effect, it was far less than that of hydrolysates. The hydrolysates of deer bone gelatin can work as a radical stabilizer and metal ion chelator to inhibit lipid oxidation.
基金supported by Chinese Scientific and Technological Major Special Project(2014ZX09J13103-01B-003 and 2014ZX09J15104002)
文摘OBJECTIVE To observe the anti-aging effects of SOD mimic AEOL^(-1)0150 in antisenescence accelerated mouse resistant 1(SAMR1)strain.METHODS The lifespan of SAMR1 mice were observed by subcutaneous injection AEOL^(-1)0150 2 mg·kg-1once a week.Morris water maze,new object recognition,nesting and forced swimming were used to observe the behavioral changes of animals.Lymphocyte subgroups and ROS were measured by Flow cytometry.The cytokines levels were determined by Luminex method.The number of DCX+neurons in brain tissue was observed by immunofluorescence.RESULTS The results showed that AEOL^(-1)0150 could prolong the mean lifespan of SAMR1 mice,but it had no obvious effect on maximal lifespan.What′s more,AEOL^(-1)0150 could significantly improve the spatial learning memory of aged mice,but it could not increase the number of DCX+neurons in the hypothalamic MBH and hippocampal DG regions.Then,we observed the effects of AEOL^(-1)0150 on peripheral blood lymphocyte subgroups and cytokines.We found that AEOL^(-1)0150significantly modulated the lymphocyte subgroups and cytokine release.Especially,AEOL^(-1)0150 can dose-dependently inhibit plasma levels of SASP related inflammatory cytokines TNF-αand IL^(-1)7.CONCLUSION The results indicate that AEOL^(-1)0150 has anti-aging effects,and the effects are closely related to modulating immunity and inhibiting SASP production.
文摘Suaeda salsa an annual herb of Chenopodiaceae Suaeda well accepted as both a folk medicinal and food plant.In the current study,the extraction of total flavonoids from S.salsa and the in vitro antioxidant,hypoglycemic and hypolipidemic activities of the extracts were investigated.The total flavonoids was extracted by refluxing with ethanol and the selection and optimization of main experimental parameters were carried out using single factor experiments combined with central composite design-response surface methodology(CCD-RSM).The total flavonoids extracted from S.salsa were tested for hydroxyl and oxygen radical scavenging activity,and inhibitory activities againstα-amylase and lipase in vitro.Results revealed that the optimal conditions for the extraction of total flavonoids were as following:liquid-tosolid ratio,31.40:1;ethanol concentration,83.12%;reflux temperature,90℃,and reflux time,128.40 min.Under these optimized conditions,the predicted and actual values of total flavonoids yield were 0.896%and 0.932%,respectively.The in vitro antioxidant tests revealed that the total flavonoids could scavenge hydroxyl and oxygen radicals and showed inhibitory activity againstα-amylase and lipase.The optimal extraction conditions obtained in this experiment are simple to perform and have good reproducibility.The results have demonstrated that the total flavonoids from S.salsa can be used as a potential source of natural antioxidant,hypoglycemic and hypolipidemic ingredients,which provides new pharmacological basis for the development of S.salsa.
基金Supported by the Special Foundation of Technological Innovation Project of Harbin (DEDE-2010RFXXN041)
文摘This study was to investigate the effects of cold stress on the contents of total antioxidant capacity （T-AOC） malondialdehyde （MDA） and superoxide dismutase （SOD） in duodenum, jejunum and ileum of chickens. A total of 80 15-dayold male chickens were treated by cold stress with the duration of the acute cold stress being 1, 3, 6, 12, and 24 h, and the chronic cold stress was 5, 10, and 20 days, respectively. Cold stress temperature was （12±1）℃. The chemical colorimetric method was used to detect the changes of the T-AOC, SOD activities and MDA contents. The results showed that compared with the corresponding control group, effects of acute cold stress on the T-AOC in duodenum, jejunum and ileum of chickens significantly （P〈0.05） increased firstly and then decreased. Under chronic cold stress, the T-AOC significantly （P〈0.05） decreased. Under acute cold stress and chronic cold stress, the MDA contents significantly （P〈0.05） increased in duodenum, jejunum and ileum of chickens. The effects of acute cold stress on the SOD activities in duodenum, jejunum and ileum of chickens significantly （P〈0.05） increased firstly and then decreased Under chronic cold stress the SOD activities significantly （P〈0.05） decreased in jejunum and ileum, but significantly （P〈0.05） decreased firstly and then increased in duodenum.
基金Project(20576142) supposed by the National Natural Science Foundation of China Project(2009DFA31270) supported by the International Cooperation Project of Ministry of Science and Technology of China
文摘A reliable ultrasound-assisted extraction （UAE） method combined with HPLC-UV for quantification of eight active alkaloids in fruits of Macleaya cordata （Willd） R. Br. was developed. The optimization conditions of UAE were obtained by using Box-Behnken design of response surface methodology. Chromatography was carried out using a Kromasil C18 column by gradient elution with 0.1% phosphoric acid aqueous solution for HPLC-UV. All calibration curves showed good linear correlation coefficients （R^2〉0.999 6） and recoveries （from 97.3% to 104.9%） were acceptable. 1,1-diphenyl-2-picrylhydrazyl （DPPH） method was employed to test the antioxidant activity of the extract from the samples. The proposed method was successfully applied to quantifying eight components in nine samples of M.cordata, and significant variations of alkaloid contents and antioxidant aetivity of the samples from different habitats were demonstrated. It presents a powerful proof for the selection of the best sources to extract eight kinds of alkaloids.
基金Supported by the National Natural Science Foundation(31201356)Agricultural Science and Technology Innovation in Jiangsu Province(cx(13)3087)the Natural Science Foundation in Jiangsu Province(BK 20130701)
文摘The antioxidant activities and the total phenolic contents of the water and/or ethanol extracts of the nine selected culinary spices from China were systematically investigated. Both ethanol extracts and water extracts had high ability of 1, 1-diphenyl-2-picrylhydrazyl（DPPH） radical scavenging, 2, 2＇-azinobis（3-ethylbenzthiazoline-6-sulphonic acid）（ABTS） radical scavenging and ferric reducing antioxidant power（FRAP）. The ethanol extract of Sichuan pepper showed the highest ability of DPPH radical scavenging. The extract with the highest ABTS radical scavenging effect was that of ethanol extract of cinnamon. Both ethanol and water extracts of cinnamon possessed the high ferric reducing antioxidant power（FRAP） with the values of 4 541.87 and 1 134.52 μmol of Fe（Ⅱ）/g. The extracts with high hydroxyl radical-mediated deoxyribose degradation were all the ethanol extracts as follows： cinnamon, bay leaf, Sichuan pepper, star anise and fennel. The extracts with high antioxidant activities also had the high contents of the phenols. The study indicated that these spices might be potentially be used as natural antioxidants in food.
文摘Wheat germ protein hydrolysates were prepared by protease hydrolysis, ultrafiltration and dynamical adsorption of resin. The total amount of amino acids in 100 g wheat germ protein hydrolysates is 93.95 g. Wheat germ protein hydrolysates are primarily composed of 4 fractions: 17.78% in the relative molecular mass range of 115631512, 17.50% in 1512842, 27.38% in 842372 and 30.65% in 37276, respectively. The antioxidant properties of wheat germ protein hydrolysates were evaluated by using different antioxidant tests in vitro. 1.20 g/L wheat germ protein hydrolysates exhibit 78.75% inhibition of peroxidation in linolei acid system; and 1.6g/L wheat germ protein hydrolysates show 81.11% scavenging effect on the 1,1-diphenyl-2-picrylhrazyl radical. The reducing power of 2.50 g/L wheat germ protein hydrolysates is 0.84. Furthermore, the scavenging activity of 0.60 g/L wheat germ protein hydrolysates against superoxide radical is 75.40%; 0.50 g/L wheat germ protein hydrolysates exhibit 63.35% chelating effect on ferrous ion. These antioxidant activities of wheat germ protein hydrolsates increase with the increase of its concentration. Experimental results suggest that wheat germ protein hydrolysate is a suitable natural antioxidant rich in nutrition and nontoxic.
基金Project(21176263) supported by the National Natural Science Foundation of China
文摘The human plasma protein binding of water soluble flavonoids in the peels of five spices of citrus fruits was studied by ultrafiltration combined with HPLC.The flavonoids were extracted separately by hot and cold water,and higher total flavonoid contents were detected in the former extracts than the latter ones.All the extracts show significant scavenging abilities to both ABTS and DPPH free radicals,which indicates the health benefits of the water extracts of citrus fruits peels.For DPPH radical,the IC50values of hot extract follow as Navel orange(NO)≈Mandarin orange(MO)< Lemon(LE)< Lo tangerine(LO)< Pomelo(PO),while the rank is NO< PO<LE≈MO<LO for ABTS radical.The HPLC results reveal that the kinds and contents of the flavonoids detected in the extracts are different among the species.MO extract has the most neohesperidin dihydrochalcone of 118.76 μmol/L and quercetrin of 211.81 μmol/L of which are much more than the rest extracts.Pomelo extract has the most plentiful flavonoids of naringin with a concentration of 303.28 μmol/L.The high contents of myricetrin and dihydromyricetin which both are potent free radical scavengers may explain the highest free radical scavenging activity of the NO extract.The plasma binding rates decrease with the increasing concentrations of flavonoids,and the flavonoids having plenty hydroxyl groups on both A ring and B ring of the molecular skeleton have relative higher plasma binding rates.In addition,the plasma binding rates of flavonoids with saturated C3-C4 bond decrease significantly with the increasing concentrations.
文摘To investigate the effects of allicin on chickens＇ lipid and antioxidant performance, Hy-laying hens＇ diets were replenished with 0 mg · kg-1, 50 mg · kg-1, 100 mg · kg-1, and 150 mg · kg-1 allicin for 42 days, respectively. The alanine aminotransferase（ALT）, aspartate aminotransferase（AST）, triglyceride（TG）, total cholesterol（TCHO）, high density lipoprotein（HDL）, and low density lipoprotein（LDL） levels were measured in chicken serum. Superoxide dismutase（SOD）, glutathione peroxidase（GSH-Px） activity and malondialdehyde（MDA） levels were measured in chicken serum and liver tissue homogenate. The results showed that the supplement dose of allicin tested did not significantly change the activity of ALT or AST（P〉0.05）; TG and CHOL levels decreased with the increase of allicin additive doses, and the difference between treatment groups and CG was significant（P〈0.05）, and there was the best effect with 100 mg · kg-1; allicin significantly reduced the content of MDA, and increased SOD and GSH-Px activities compared with CG（P〈0.05）, and 100 mg · kg-1 of allicin resulted in the strongest SOD and GSH-Px activity. The antioxidant function test results of liver tissue homogenate were consistant with that of serum. Our findings indicated that allicin could enhance antioxidant capacity and reduce blood lipid level in chickens and 100 mg · kg-1 was the optimal amount of allicin additives.
文摘The fresh leaves and oven dried leaves from three varieties of black currant (Brodtrop,liangye,Risager)were analysed for the total contents of flavonoids by spectrophotometric methods in terms of rutin equivalent.In addition,antioxidant activities of different addition amounts of extracts of black currant (Brodtrop)leaves in lard were measured by the Oven-Storage Test,and compared with the synthetic antioxidants.The results showed the contents of the flavonoids were very rich in the leaves of three varieties from black currant.Among them the leaves of Brodtrop had the highest contents of flavonoids followed by liangye and Risager.The total contents of flavonoids in fresh leaves reach 231 70 mg/100 g,170 01 mg/100 g and 78 07 mg/100 g respectively.In the same circumstance the oven dried leaves were 397 82 mg/100 g,275 89 mg/100 g and 169 73 mg/100 g.The extracts of the leaves from Brodtrop exhibited strong antioxidant activities on lard,which increased with the addition amount of the flavonoid extracts.The antioxidant activities decreased in the order of 0 02% quercetin >0 02% BHT(butylated hydroxy toluene)>0 40% extracts>0 20% extracts>0 10% extracts>0 05% extracts>0 02% extracts>control.
基金Project(41771512)supported by the National Natural Science Foundation of ChinaProject(2018RS3004)supported by Hunan Science&Technology Innovation Program,China
文摘This study investigated the chromium(Cr)detoxification mechanism-induced changes in growth and antioxidant defence enzyme activities in Chrysopogon zizanioides.Plant growth decreased by 36.8%and 45.0%in the shoots and roots,respectively,in the 50 mg/L Cr treatment.Cr accumulation was higher in root(9807μg/g DW)than in shoots(8730μg/g DW).Photosynthetic pigments and malondialdehyde content increased up to the 30 mg/L Cr treatment,whereas they declined at higher doses.The activity of superoxide dismutase(SOD),catalase(CAT)and peroxidase(POX)were increased significantly with increasing of Cr dose but slightly declined at higher doses.Isozyme banding patterns revealed the expression of multiple bands for SOD,CAT and POX enzymes,and the band intensity decreased at high doses of Cr exposure.These results indicate that higher Cr doses increased the oxidative stress by over production of reactive oxygen species(ROS)in vetiver that had potential tolerance mechanism to Cr as evidenced by enhanced level of antioxidative enzymes,photosynthetic pigments,MDA contents.Therefore,vetiver has evolved a mechanism for detoxification and accumulates higher concentration of toxic Cr.This study provides a better understanding of how vetiver detoxifies Cr.
