Dried ground leaves of Psidium 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 ...Dried ground leaves of Psidium 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 Folin- Ciocalteu’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 evalu- ated 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 ade- quate parameter for selecting antioxidants than the widely used EC50. This study revealed that guava leaf extracts comprise effective potential source of natural antioxidants.展开更多
Objective:To evaluate the antioxidant activity of aqueous extract of Atoringa oleifeta M.oleifera) young leaves by in vivo as well as in vitro assays.Methods:In vitro study included estimation of total phenolic,total ...Objective:To evaluate the antioxidant activity of aqueous extract of Atoringa oleifeta M.oleifera) young leaves by in vivo as well as in vitro assays.Methods:In vitro study included estimation of total phenolic,total ilavonol,total flavonoid and total antioxidant power(FRAP assay).Tn addition, in vivo study was done with the identified most effective dose of 200 nig/kg of its lyophilized powder on normal and diabetic rats.Its effect on different oxidative free radical scavenging enzymes,viz,superoxide dismutase(SOD),catalase(CAT),glutathione-S-transferase(GST),lipid peroxide(LPO) contents were measured.Results:Significant increase in activities of SOD.CAT, GST while,a decrease in LPO content was observed.Whereas,total phenolic,flavonoid and ilavonol contents in the extract were found to be 120 mg/g of CAK,40.5 mg/g of QEK and 12.12 mg/g of QE,respectively.On the other hand.FRAP assay results of M.oleifera leaves was(85.00±5.00)μM of Fe^+/g of extract powder.Conclusions:The significant antioxidant activities of M.oleifera leaves from both in vivo as well as in vitro studies suggests that the regular intake of its leaves through diet can protect normal as well as diabetic patients against oxidative damage.展开更多
Ultrasonic extraction （UE） was employed for the extraction of bamboo leaf polysaccharides （BLP）. The influential parameters of UE procedure including extraction time, ultrasonic power and solid/liquid ratio were o...Ultrasonic extraction （UE） was employed for the extraction of bamboo leaf polysaccharides （BLP）. The influential parameters of UE procedure including extraction time, ultrasonic power and solid/liquid ratio were optimized by orthogonal experiments. DEAE-cellulose col- umn chromatography was applied to purify BLP and then the radical scavenging activity of BLP was also evaluated. Optimal extraction con- ditions were： extraction time .of 15 min, ultrasonic power of 300 W, and solid/liquid ratio of 1：15. Four kinds of polysaccharides were obtained by DEAE-cellulose colunm chromatography; the maximum superoxide radical scavenging rate （20.4%） of BLP was inferior to that of vitamin C （Vc, the control） and the hydroxyl radical scavenging rate （50%） was equivalent to that of Vc.展开更多
The present study was designed to investigate the antithrombotic effects and underlying mechanisms of the effective components group(ECG) of Xiaoshuantongluo recipe(XECG) and to further verify the rationality and feas...The present study was designed to investigate the antithrombotic effects and underlying mechanisms of the effective components group(ECG) of Xiaoshuantongluo recipe(XECG) and to further verify the rationality and feasibility of ECG-guided methodology in traditional Chinese medicine(TCM) research. The arterial thrombosis model induced by ferric chloride(FeC l3) oxidation and the venous thrombosis model induced by inferior vena cava ligation were established to evaluate the antithrombotic potential of XECG. Our results indicated that XECG significantly prolonged the time to occlusion, activated partial thromboplastin time(APTT), and prothrombin time(PT), and markedly inhibited adenosine diphosphate(ADP)-induced platelet aggregation in the 20% Fe Cl3-induced arterial thrombosis model. The superoxide dismutase(SOD) activity was significantly increased and the levels of malondialdehyde(MDA) and nitric oxide(NO) were dramatically decreased in the plasma of arterial thrombosis rats after XECG treatment for 12 days. Furthermore, XECG markedly reduced the weight of thrombus formed by inferior vena cava ligation. Additionally, XECG exhibited 2,2-diphenyl-1-picrylhydrazyl(DPPH) free radical scavenging activity and protective effect on mitochondrial lipid peroxidation. In summary, XECG played an important role in the prevention of thrombosis through interacting with multiple targets, including inhibition of platelet aggregation and coagulation and repression of oxidative stress. The ECG-guided methodology was validated as a feasible tool in TCM research.展开更多
A light purple organic active substance capable of scavenging hydroxyl radical（OH） with a high efficiency was extracted from Oyster shell at an extraction rate of 2.49%. It was found for the first time that this act...A light purple organic active substance capable of scavenging hydroxyl radical（OH） with a high efficiency was extracted from Oyster shell at an extraction rate of 2.49%. It was found for the first time that this active substance may scavenge OH with the efficiency far higher than that of vitamin C. This active substance may scavenge also superoxide radical（O2） although the scavenging efficiency is far lower than that of vitamin C. Infrared spectrometry and routine chemical analysis primarily reveal that this active substance belongs to glycoprotein.展开更多
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
文摘Dried ground leaves of Psidium 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 Folin- Ciocalteu’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 evalu- ated 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 ade- quate parameter for selecting antioxidants than the widely used EC50. This study revealed that guava leaf extracts comprise effective potential source of natural antioxidants.
基金National Medicinal Plants Board. Govt,of India,New Delhi,India for providing financial assistance in the form of Senior Research Fellowship to cam' out the present study
文摘Objective:To evaluate the antioxidant activity of aqueous extract of Atoringa oleifeta M.oleifera) young leaves by in vivo as well as in vitro assays.Methods:In vitro study included estimation of total phenolic,total ilavonol,total flavonoid and total antioxidant power(FRAP assay).Tn addition, in vivo study was done with the identified most effective dose of 200 nig/kg of its lyophilized powder on normal and diabetic rats.Its effect on different oxidative free radical scavenging enzymes,viz,superoxide dismutase(SOD),catalase(CAT),glutathione-S-transferase(GST),lipid peroxide(LPO) contents were measured.Results:Significant increase in activities of SOD.CAT, GST while,a decrease in LPO content was observed.Whereas,total phenolic,flavonoid and ilavonol contents in the extract were found to be 120 mg/g of CAK,40.5 mg/g of QEK and 12.12 mg/g of QE,respectively.On the other hand.FRAP assay results of M.oleifera leaves was(85.00±5.00)μM of Fe^+/g of extract powder.Conclusions:The significant antioxidant activities of M.oleifera leaves from both in vivo as well as in vitro studies suggests that the regular intake of its leaves through diet can protect normal as well as diabetic patients against oxidative damage.
文摘Ultrasonic extraction （UE） was employed for the extraction of bamboo leaf polysaccharides （BLP）. The influential parameters of UE procedure including extraction time, ultrasonic power and solid/liquid ratio were optimized by orthogonal experiments. DEAE-cellulose col- umn chromatography was applied to purify BLP and then the radical scavenging activity of BLP was also evaluated. Optimal extraction con- ditions were： extraction time .of 15 min, ultrasonic power of 300 W, and solid/liquid ratio of 1：15. Four kinds of polysaccharides were obtained by DEAE-cellulose colunm chromatography; the maximum superoxide radical scavenging rate （20.4%） of BLP was inferior to that of vitamin C （Vc, the control） and the hydroxyl radical scavenging rate （50%） was equivalent to that of Vc.
基金supported by the Major Scientific and Technological Special Project for"Significant New Drugs Creation"(No.2013ZX09508104001002)the National Natural Science Foundation of China(No.81273652)
文摘The present study was designed to investigate the antithrombotic effects and underlying mechanisms of the effective components group(ECG) of Xiaoshuantongluo recipe(XECG) and to further verify the rationality and feasibility of ECG-guided methodology in traditional Chinese medicine(TCM) research. The arterial thrombosis model induced by ferric chloride(FeC l3) oxidation and the venous thrombosis model induced by inferior vena cava ligation were established to evaluate the antithrombotic potential of XECG. Our results indicated that XECG significantly prolonged the time to occlusion, activated partial thromboplastin time(APTT), and prothrombin time(PT), and markedly inhibited adenosine diphosphate(ADP)-induced platelet aggregation in the 20% Fe Cl3-induced arterial thrombosis model. The superoxide dismutase(SOD) activity was significantly increased and the levels of malondialdehyde(MDA) and nitric oxide(NO) were dramatically decreased in the plasma of arterial thrombosis rats after XECG treatment for 12 days. Furthermore, XECG markedly reduced the weight of thrombus formed by inferior vena cava ligation. Additionally, XECG exhibited 2,2-diphenyl-1-picrylhydrazyl(DPPH) free radical scavenging activity and protective effect on mitochondrial lipid peroxidation. In summary, XECG played an important role in the prevention of thrombosis through interacting with multiple targets, including inhibition of platelet aggregation and coagulation and repression of oxidative stress. The ECG-guided methodology was validated as a feasible tool in TCM research.
基金Supported by the Natural Science Foundation of Fujian Province, China(NoC0510029)the Specialized Foundation for Creative Team of Young and Middle-aged Teachers of Jimei University, China(No2006A003)
文摘A light purple organic active substance capable of scavenging hydroxyl radical（OH） with a high efficiency was extracted from Oyster shell at an extraction rate of 2.49%. It was found for the first time that this active substance may scavenge OH with the efficiency far higher than that of vitamin C. This active substance may scavenge also superoxide radical（O2） although the scavenging efficiency is far lower than that of vitamin C. Infrared spectrometry and routine chemical analysis primarily reveal that this active substance belongs to glycoprotein.
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.
