Antioxidants have attracted the attention of researchers due to their beneficial effects as free radical scavengers. Application of a stable free radical named 1,1 diphenyl 2 picrylhydrazyl(DPPH) to screen the free ra...Antioxidants have attracted the attention of researchers due to their beneficial effects as free radical scavengers. Application of a stable free radical named 1,1 diphenyl 2 picrylhydrazyl(DPPH) to screen the free radical scavenging activity in 27 species of Chinese seaweed showed that 15 of them had significant activity in at least one of the organic solvent extracts. The most interesting seaweed species were Gelidium amansii, Gloiosiphonia capillaris, Polysiphonia urceolata, Sargassum kjellmanianum, Desmarestia viridis, and Rhodomela teres.展开更多
[Objectives]To study the antioxidant activity of different solvent extracts of Gynura segetum in vitro,so as to provide experimental basis for further study and utilization of medicinal resources of G.segetum.[Methods...[Objectives]To study the antioxidant activity of different solvent extracts of Gynura segetum in vitro,so as to provide experimental basis for further study and utilization of medicinal resources of G.segetum.[Methods]The antioxidant activity of different solvent extracts of G.segetum was determined by UV-vis spectrophotometer using DPPH free radical scavenging method and ABTS^+free radical scavenging method.[Results]The scavenging rates of DPPH and ABTS^+by acetone extract were high,reaching 98.9%and 98.3%,respectively;the scavenging rate of DPPH and ABTS^+by water extract was the lowest,and the scavenging rates were 76.7%and 77.5%,respectively.The order of ABTS^+radical scavenging rate of samples extracted with different extractants was as follows:S 5(acetone extract)>S 1(ethyl acetate extract)>S 6(ethanol extract)>S 4(n-butanol extract)>S 3(methanol extract)>S 2(distilled water extract);the order of DPPH radical scavenging rate of samples extracted with different extractants was as follows:S 5(acetone extract)>S 1(ethyl acetate extract)>S 4(n-butanol extract)>S 6(ethanol extract)>S 3(methanol extract)>S 2(distilled water extract).[Conclusions]The extracts of acetone,ethyl acetate,n-butanol,anhydrous ethanol,methanol and distilled water from the roots of G.segetum had obvious scavenging effects on DPPH and ABTS^+,all had antioxidant components,and acetone had the highest antioxidant effect as an extractant.展开更多
Glycyrrhiza glabra L.is the most widely used herb in the ancient history of Ayurvedic medicine,as a medicinal value as well as an aromatic herb,and it is commonly known as Mulhatti.Mulhatti roots are useful for medica...Glycyrrhiza glabra L.is the most widely used herb in the ancient history of Ayurvedic medicine,as a medicinal value as well as an aromatic herb,and it is commonly known as Mulhatti.Mulhatti roots are useful for medically and are also a good source of phytoproducts and secondary metabolites present in Mulhatti roots are triterpenoid saponin,glycosides,glycyrrhizin,prenylated biaurone,licoaagrone,7-acetoxy-2-methylisoflavone,4-methylcoumarin,liqcoumarin,glycyrrhetinic acid,quercetin,liquiritigenin,isoliquiritigenin,etc.This study was carried out to study the evaluation of phenolic compounds,2,2-diphenyl-1-picrylhydrazyl(DPPH)free radical activity and general antioxidant capacity of water extracts of Mulhatti roots prepared at different pH values,namely 2,4,7 and 9.Data have shown great differences in terms of results.Most of the phenolic compounds are at pH 7(19.25),followed by pH 9(17.25),pH 2(14.62)and pH 4(8.89 mg GAE/g),respectively.Similarly,the flavonoid data also showed variations,the maximum has been present in pH 2(5.39),then pH 7(3.02),pH 9(1.79)and pH 4(1.40 mg CE/g),respectively.The value for DPPH IC50 free radical scavenging activity was the lowest at pH 7(82.22),followed by pH 2(110.40),pH 4(111.99)and pH 9(146.24μg/mL)and IC50 reference standard(ascorbic acid)was 59.52μg/mL in distilled water.The total capacity of the antioxidant was the highest at pH 2(9.93)followed by pH 4(5.54),pH 7(5.34)and pH 9(4.23 mg AAE/g).According to current research,pH 7 is the best for phytochemicals as well as antioxidants that catch harmful radicals.展开更多
Dried ground leaves ofPsidium guajava L. (guava) were extracted by water and aqueous ethyl alcohol 50%(1:10) ratio, and the total phenolic content in the extracts was determined spectrophotometrically according to Fol...Dried ground leaves ofPsidium guajava L. (guava) were extracted by water and aqueous ethyl alcohol 50%(1:10) ratio, and the total phenolic content in the extracts was determined spectrophotometrically according to FolinCiocalteu's phenol method and calculated as gallic acid equivalent (GAE). Remarkably high total phenolic content 575.3±15.5 and 511.6±6.2 mg of GAE/g of dried weight material (for ethanol guava leaf extracts and water guava leaf extracts,respectively) were obtained. The antioxidant activity of lyophilized extracts was determined at ambient temperature by means of a 2,2-diphenyl-1-picrylhydryzyl (DPPH') colorimetry with detection scheme at 515 nm. The activity was evaluated by the decrease in absorbance as the result of DPPH" color change from purple to yellow. The higher the sample concentration used, the stronger was the free radical-scavenging effect. The results obtained showed that ascorbic acid was a substantially more powerful antioxidant than the extracts from guava leaf. On the other hand, the commercial guava leaf extracts and ethanol guava leaf extracts showed almost the same antioxidant power whereas water guava leaf extracts showed lower antioxidant activity. The parameter EC50 and the time needed to reach the steady state to EC50 concentration (TEC50) affected the antiradical capacity of the sample. The antioxidant efficiency (AE) has been shown to be a more adequate parameter for selecting antioxidants than the widely used ECs0. This study revealed that guava leaf extracts comprise effective potential source of natural antioxidants.展开更多
Reactive oxygen species [ROS] cause oxidative damage to the tissues and protection from such damages is provided by endogenous and exogenous antioxidants. Much research work has been carried out in recent years on the...Reactive oxygen species [ROS] cause oxidative damage to the tissues and protection from such damages is provided by endogenous and exogenous antioxidants. Much research work has been carried out in recent years on the beneficial effect of phenolic compounds which act as natural antioxidants and help to neutralize free radicals. So, this study was aimed to evaluate the in vitro antioxidant capacity of one of the phenolic compounds phloretin. Phloretin was used at four different concentrations like 20, 40, 60 and 80 μg/ml to determine the antioxidant activity by different methods such as total antioxidant capacity, reducing power, DPPH radical scavenging, superoxide anion radical scavenging and metal chelating assays. In addition to that the ascorbic acid was used as reference compound. The results showed that the phloretin displayed potent in vitro antioxidant capacity. It was able to scavenge different in vitro free radicals in all tested concentrations. Among the different concentrations, 80 μg of phloretin has maximum activity when compared to other concentrations in all in vitro antioxidant assays. High antioxidant property and maximum protective effect of phloretin were observed in a concentration dependent manner. The results were expressed as IC<sub>50</sub> value. The lowest IC<sub>50 </sub>value indicates the highest scavenging activity. The reducing power of the phloretin was also found in concentration dependent. According to the results of this study, we concluded that the phloretin possesses antioxidant property. Therefore, phloretin is a powerful antioxidant phytocompound which can protect biological systems against the oxidative stress. From this study, we suggest that the phloretin may be used as a dietary natural antioxidant supplement for preventing free radical related diseases.展开更多
文摘Antioxidants have attracted the attention of researchers due to their beneficial effects as free radical scavengers. Application of a stable free radical named 1,1 diphenyl 2 picrylhydrazyl(DPPH) to screen the free radical scavenging activity in 27 species of Chinese seaweed showed that 15 of them had significant activity in at least one of the organic solvent extracts. The most interesting seaweed species were Gelidium amansii, Gloiosiphonia capillaris, Polysiphonia urceolata, Sargassum kjellmanianum, Desmarestia viridis, and Rhodomela teres.
文摘[Objectives]To study the antioxidant activity of different solvent extracts of Gynura segetum in vitro,so as to provide experimental basis for further study and utilization of medicinal resources of G.segetum.[Methods]The antioxidant activity of different solvent extracts of G.segetum was determined by UV-vis spectrophotometer using DPPH free radical scavenging method and ABTS^+free radical scavenging method.[Results]The scavenging rates of DPPH and ABTS^+by acetone extract were high,reaching 98.9%and 98.3%,respectively;the scavenging rate of DPPH and ABTS^+by water extract was the lowest,and the scavenging rates were 76.7%and 77.5%,respectively.The order of ABTS^+radical scavenging rate of samples extracted with different extractants was as follows:S 5(acetone extract)>S 1(ethyl acetate extract)>S 6(ethanol extract)>S 4(n-butanol extract)>S 3(methanol extract)>S 2(distilled water extract);the order of DPPH radical scavenging rate of samples extracted with different extractants was as follows:S 5(acetone extract)>S 1(ethyl acetate extract)>S 4(n-butanol extract)>S 6(ethanol extract)>S 3(methanol extract)>S 2(distilled water extract).[Conclusions]The extracts of acetone,ethyl acetate,n-butanol,anhydrous ethanol,methanol and distilled water from the roots of G.segetum had obvious scavenging effects on DPPH and ABTS^+,all had antioxidant components,and acetone had the highest antioxidant effect as an extractant.
文摘Glycyrrhiza glabra L.is the most widely used herb in the ancient history of Ayurvedic medicine,as a medicinal value as well as an aromatic herb,and it is commonly known as Mulhatti.Mulhatti roots are useful for medically and are also a good source of phytoproducts and secondary metabolites present in Mulhatti roots are triterpenoid saponin,glycosides,glycyrrhizin,prenylated biaurone,licoaagrone,7-acetoxy-2-methylisoflavone,4-methylcoumarin,liqcoumarin,glycyrrhetinic acid,quercetin,liquiritigenin,isoliquiritigenin,etc.This study was carried out to study the evaluation of phenolic compounds,2,2-diphenyl-1-picrylhydrazyl(DPPH)free radical activity and general antioxidant capacity of water extracts of Mulhatti roots prepared at different pH values,namely 2,4,7 and 9.Data have shown great differences in terms of results.Most of the phenolic compounds are at pH 7(19.25),followed by pH 9(17.25),pH 2(14.62)and pH 4(8.89 mg GAE/g),respectively.Similarly,the flavonoid data also showed variations,the maximum has been present in pH 2(5.39),then pH 7(3.02),pH 9(1.79)and pH 4(1.40 mg CE/g),respectively.The value for DPPH IC50 free radical scavenging activity was the lowest at pH 7(82.22),followed by pH 2(110.40),pH 4(111.99)and pH 9(146.24μg/mL)and IC50 reference standard(ascorbic acid)was 59.52μg/mL in distilled water.The total capacity of the antioxidant was the highest at pH 2(9.93)followed by pH 4(5.54),pH 7(5.34)and pH 9(4.23 mg AAE/g).According to current research,pH 7 is the best for phytochemicals as well as antioxidants that catch harmful radicals.
文摘Dried ground leaves ofPsidium guajava L. (guava) were extracted by water and aqueous ethyl alcohol 50%(1:10) ratio, and the total phenolic content in the extracts was determined spectrophotometrically according to FolinCiocalteu's phenol method and calculated as gallic acid equivalent (GAE). Remarkably high total phenolic content 575.3±15.5 and 511.6±6.2 mg of GAE/g of dried weight material (for ethanol guava leaf extracts and water guava leaf extracts,respectively) were obtained. The antioxidant activity of lyophilized extracts was determined at ambient temperature by means of a 2,2-diphenyl-1-picrylhydryzyl (DPPH') colorimetry with detection scheme at 515 nm. The activity was evaluated by the decrease in absorbance as the result of DPPH" color change from purple to yellow. The higher the sample concentration used, the stronger was the free radical-scavenging effect. The results obtained showed that ascorbic acid was a substantially more powerful antioxidant than the extracts from guava leaf. On the other hand, the commercial guava leaf extracts and ethanol guava leaf extracts showed almost the same antioxidant power whereas water guava leaf extracts showed lower antioxidant activity. The parameter EC50 and the time needed to reach the steady state to EC50 concentration (TEC50) affected the antiradical capacity of the sample. The antioxidant efficiency (AE) has been shown to be a more adequate parameter for selecting antioxidants than the widely used ECs0. This study revealed that guava leaf extracts comprise effective potential source of natural antioxidants.
文摘Reactive oxygen species [ROS] cause oxidative damage to the tissues and protection from such damages is provided by endogenous and exogenous antioxidants. Much research work has been carried out in recent years on the beneficial effect of phenolic compounds which act as natural antioxidants and help to neutralize free radicals. So, this study was aimed to evaluate the in vitro antioxidant capacity of one of the phenolic compounds phloretin. Phloretin was used at four different concentrations like 20, 40, 60 and 80 μg/ml to determine the antioxidant activity by different methods such as total antioxidant capacity, reducing power, DPPH radical scavenging, superoxide anion radical scavenging and metal chelating assays. In addition to that the ascorbic acid was used as reference compound. The results showed that the phloretin displayed potent in vitro antioxidant capacity. It was able to scavenge different in vitro free radicals in all tested concentrations. Among the different concentrations, 80 μg of phloretin has maximum activity when compared to other concentrations in all in vitro antioxidant assays. High antioxidant property and maximum protective effect of phloretin were observed in a concentration dependent manner. The results were expressed as IC<sub>50</sub> value. The lowest IC<sub>50 </sub>value indicates the highest scavenging activity. The reducing power of the phloretin was also found in concentration dependent. According to the results of this study, we concluded that the phloretin possesses antioxidant property. Therefore, phloretin is a powerful antioxidant phytocompound which can protect biological systems against the oxidative stress. From this study, we suggest that the phloretin may be used as a dietary natural antioxidant supplement for preventing free radical related diseases.
