A new analytical procedure based on solid-phase extraction method coupled to GC-FID has been developed and validated for the determination of five phthalate esters （PAEs） （dimethyl-（DMP）, diethyl-（DEP）, di-n-bu...A new analytical procedure based on solid-phase extraction method coupled to GC-FID has been developed and validated for the determination of five phthalate esters （PAEs） （dimethyl-（DMP）, diethyl-（DEP）, di-n-butyl-（DBP）, di-2-ethylhexyl- （DEHP）, di-n-octyl-（DOP）） in fish samples. There was a good linear relationship in the range of 0.05-10μg with the detection limits of 0.09-0.16ng .The recoveries obtained for PAEs ranged from 88.6% to 96.4%with RSD of 4.2%-10.2%.The applicability of the developed method was demonstrated for real fish samples.展开更多
We have extracted and purified flavonoids as active ingredients from Ceylon green tea （Dilmah）. In this project, an in vitro hypoxic model using human brain epithelial cells （HBEC） was studied with treatment of th...We have extracted and purified flavonoids as active ingredients from Ceylon green tea （Dilmah）. In this project, an in vitro hypoxic model using human brain epithelial cells （HBEC） was studied with treatment of the tea extract before inducing hypoxia. We have tested the hypothesis that flavonoids extracted from Ceylon green tea act as potential therapeutic ingredient （s） to reduce oxidative stress in hypoxic cells through its antioxidant properties and its ability to reduce cerebral cellular death. The biochemical antioxidant tests show that the Ceylon green tea has 68% ± 2.8% inhibition property of scavenging of ABTS. The inhibition of pyrogallol red bleaching by HOCI from Ceylon tea was 79% ± 4.5%. After exposing to hypoxia, the cell viability was 29% ± 2.3% in the hypoxia control group but 41% ± 4.7% for flavonoids extract treated group. In LDH assay, flavonoids extract treated group had 75% ± 3.7% reducing of LDH release. The flavonoids extract treated groups significantly increased in antioxidant enzyme activity assays： the activity level of SOD [（1.5 ± 0.6） μmol/min/mg protein], CAT [（0.61 ± 0.06） μmol/min/mg protein], GPx [（2.6 ± 0.41） μmol/min/mg protein] and GST [（6.0 ± 2.4） μmol/min/mg protein] are significantly increased as compared with hypoxic control [（0.5 ± 0.52, 0.51 ± 0.04, 1.2 ± 0.35 and 3.1 ± 1.6） μmol/min/mg protein, respectively]. The study demonstrated a great clinical potential and opened a new avenue to prevent stroke by drinking Ceylon tea.展开更多
OBJECTIVE: The purpose of this study was to evaluate the antioxidant activity, phenolic and flavonoids contents of selected medicinal plants form the Western region of Nepal.METHODS: The antioxidant activity of select...OBJECTIVE: The purpose of this study was to evaluate the antioxidant activity, phenolic and flavonoids contents of selected medicinal plants form the Western region of Nepal.METHODS: The antioxidant activity of selected medicinal plants were determined by using 2, 2-diphenyl-1-picrylhydrazyl radical scavenging activity; total ferric ion reducing ability through spectroscopic analysis. The content of total phenols was determined using Folin-Ciocalteu reagent, whereas Aluminum chloride colorimetric method was used for flavonoid determination.RESULTS: Extracts of Syzygium Operculatus(87%),Astilbe Rivularis(83%) and Mallotus Philippnensis(88%) showed significant free radical scavenging activity with effective concentration(EC50) close to that of ascorbic acid. Syzygium Operculatus(96%),Astilbe Rivularis(97%) and Mallotus Philippnensis(97%) had potent reducing power in concentration dependent fashion. Those plant extract with higher free radical scavenging and ferric reducing effect also showed the greater content of both phenols and flavonoids, suggesting the correlation between polyphenolic content and antioxidant activity. Those plant extracts which showed better antioxidant activity assays, also demonstrated higher total phenol and flavonoid contents. These three plants showed the presence of higher amount of phenols and flavonoids.CONCLUSION: This study may provide the scientific basis for the traditional use of those plants and may provide valuable idea for further research.展开更多
文摘A new analytical procedure based on solid-phase extraction method coupled to GC-FID has been developed and validated for the determination of five phthalate esters （PAEs） （dimethyl-（DMP）, diethyl-（DEP）, di-n-butyl-（DBP）, di-2-ethylhexyl- （DEHP）, di-n-octyl-（DOP）） in fish samples. There was a good linear relationship in the range of 0.05-10μg with the detection limits of 0.09-0.16ng .The recoveries obtained for PAEs ranged from 88.6% to 96.4%with RSD of 4.2%-10.2%.The applicability of the developed method was demonstrated for real fish samples.
文摘We have extracted and purified flavonoids as active ingredients from Ceylon green tea （Dilmah）. In this project, an in vitro hypoxic model using human brain epithelial cells （HBEC） was studied with treatment of the tea extract before inducing hypoxia. We have tested the hypothesis that flavonoids extracted from Ceylon green tea act as potential therapeutic ingredient （s） to reduce oxidative stress in hypoxic cells through its antioxidant properties and its ability to reduce cerebral cellular death. The biochemical antioxidant tests show that the Ceylon green tea has 68% ± 2.8% inhibition property of scavenging of ABTS. The inhibition of pyrogallol red bleaching by HOCI from Ceylon tea was 79% ± 4.5%. After exposing to hypoxia, the cell viability was 29% ± 2.3% in the hypoxia control group but 41% ± 4.7% for flavonoids extract treated group. In LDH assay, flavonoids extract treated group had 75% ± 3.7% reducing of LDH release. The flavonoids extract treated groups significantly increased in antioxidant enzyme activity assays： the activity level of SOD [（1.5 ± 0.6） μmol/min/mg protein], CAT [（0.61 ± 0.06） μmol/min/mg protein], GPx [（2.6 ± 0.41） μmol/min/mg protein] and GST [（6.0 ± 2.4） μmol/min/mg protein] are significantly increased as compared with hypoxic control [（0.5 ± 0.52, 0.51 ± 0.04, 1.2 ± 0.35 and 3.1 ± 1.6） μmol/min/mg protein, respectively]. The study demonstrated a great clinical potential and opened a new avenue to prevent stroke by drinking Ceylon tea.
基金Supported by the Student Research Fund from the Department of Pharmaceutical Sciences,School of Health and Allied Sciences,Pokhara University(2068)
文摘OBJECTIVE: The purpose of this study was to evaluate the antioxidant activity, phenolic and flavonoids contents of selected medicinal plants form the Western region of Nepal.METHODS: The antioxidant activity of selected medicinal plants were determined by using 2, 2-diphenyl-1-picrylhydrazyl radical scavenging activity; total ferric ion reducing ability through spectroscopic analysis. The content of total phenols was determined using Folin-Ciocalteu reagent, whereas Aluminum chloride colorimetric method was used for flavonoid determination.RESULTS: Extracts of Syzygium Operculatus(87%),Astilbe Rivularis(83%) and Mallotus Philippnensis(88%) showed significant free radical scavenging activity with effective concentration(EC50) close to that of ascorbic acid. Syzygium Operculatus(96%),Astilbe Rivularis(97%) and Mallotus Philippnensis(97%) had potent reducing power in concentration dependent fashion. Those plant extract with higher free radical scavenging and ferric reducing effect also showed the greater content of both phenols and flavonoids, suggesting the correlation between polyphenolic content and antioxidant activity. Those plant extracts which showed better antioxidant activity assays, also demonstrated higher total phenol and flavonoid contents. These three plants showed the presence of higher amount of phenols and flavonoids.CONCLUSION: This study may provide the scientific basis for the traditional use of those plants and may provide valuable idea for further research.
