Objective: To investigate the effects of the leaf ethanolic extract of Pseuderanthemum palatiferum(PPE) and its isolated phytochemicals, stigmasterol and sitosterol-3-O-b-Dglucopyranoside, against a-amylase and a-gluc...Objective: To investigate the effects of the leaf ethanolic extract of Pseuderanthemum palatiferum(PPE) and its isolated phytochemicals, stigmasterol and sitosterol-3-O-b-Dglucopyranoside, against a-amylase and a-glucosidase enzyme activities both in vitro and in vivo.Methods: A concentration of maltose, which is a product released in a-amylase-catalyzing reaction, was used as an index of in vitro a-amylase activity. Meanwhile, in vitro a-glucosidase enzyme activity was indicated by the amount of liberated p-nitrophenol in a-glucosidase-catalyzing reaction. In vivo a-amylase and a-glucosidase enzyme activities were evaluated in the normal rats by using oral starch tolerance test and oral sucrose tolerance test, respectively.Results: PPE exerted a concentration-dependent inhibitory action against both aamylase and a-glucosidase in vitro with the IC_(50) values of(11.79 ± 8.10) mg/m L and(1.00 ± 0.11) mg/m L, respectively. Stigmasterol and sitosterol-3-O-b-D-glucopyranoside also exerted an in vitro a-amylase inhibition with the IC_(50) values of(59.41 ± 8.22) mg/m L and(111.19 ± 9.02) mg/m L, respectively. However, these phytochemicals did not produce a concentration-dependent inhibition against in vitro a-glucosidase activity. PPE and its isolated phytochemicals significantly decreased the blood glucose levels at t = 30 min in the oral starch tolerance test. From the sucrose tolerance test, only PPE but not its isolated phytochemicals significantly caused a depletion in the blood glucose levels at t = 30 min Conclusions: These results indicate an inhibitory action against carbohydrate-digesting enzymes as the anti-diabetic mechanism of action of PPE. Nonetheless, further clinical study is required to justify its role in the treatment of diabetes.展开更多
This study was aimed at determining the amount of the total phenolic contents （TPCs） and to evaluate the antioxidant activities of different extracts （leaves, branches, and barks） of Phyllanthus emblica （PE） L.,
基金Supported by Mahasarakham University research grant(Grant No.5805028/2558,fiscal year 2015)
文摘Objective: To investigate the effects of the leaf ethanolic extract of Pseuderanthemum palatiferum(PPE) and its isolated phytochemicals, stigmasterol and sitosterol-3-O-b-Dglucopyranoside, against a-amylase and a-glucosidase enzyme activities both in vitro and in vivo.Methods: A concentration of maltose, which is a product released in a-amylase-catalyzing reaction, was used as an index of in vitro a-amylase activity. Meanwhile, in vitro a-glucosidase enzyme activity was indicated by the amount of liberated p-nitrophenol in a-glucosidase-catalyzing reaction. In vivo a-amylase and a-glucosidase enzyme activities were evaluated in the normal rats by using oral starch tolerance test and oral sucrose tolerance test, respectively.Results: PPE exerted a concentration-dependent inhibitory action against both aamylase and a-glucosidase in vitro with the IC_(50) values of(11.79 ± 8.10) mg/m L and(1.00 ± 0.11) mg/m L, respectively. Stigmasterol and sitosterol-3-O-b-D-glucopyranoside also exerted an in vitro a-amylase inhibition with the IC_(50) values of(59.41 ± 8.22) mg/m L and(111.19 ± 9.02) mg/m L, respectively. However, these phytochemicals did not produce a concentration-dependent inhibition against in vitro a-glucosidase activity. PPE and its isolated phytochemicals significantly decreased the blood glucose levels at t = 30 min in the oral starch tolerance test. From the sucrose tolerance test, only PPE but not its isolated phytochemicals significantly caused a depletion in the blood glucose levels at t = 30 min Conclusions: These results indicate an inhibitory action against carbohydrate-digesting enzymes as the anti-diabetic mechanism of action of PPE. Nonetheless, further clinical study is required to justify its role in the treatment of diabetes.
基金supported by the Center for Research and Development of Herbal Health Products(RD-HHP)Faculty of Pharmaceutical Sciences,Khon Kaen University,Thailand(No.RD-HHP 05)
文摘This study was aimed at determining the amount of the total phenolic contents （TPCs） and to evaluate the antioxidant activities of different extracts （leaves, branches, and barks） of Phyllanthus emblica （PE） L.,
