AIM： To investigate the hepatoprotective activity of tea polyphenols （TP） and its relation with cytochrome P450 （CYP450） expression in mice. METHODS： Hepatic CYP450 and CYPbs levels were measured by UV-spectroph...AIM： To investigate the hepatoprotective activity of tea polyphenols （TP） and its relation with cytochrome P450 （CYP450） expression in mice. METHODS： Hepatic CYP450 and CYPbs levels were measured by UV-spectrophotometry in mice 2 d after intraperitoneal TP （25, 50 and 100 mg/kg per day）. Then the mice were intragastricly pre-treated with TP （100, 200 and 400 mg/kg per day） for six days before paracetamol （1000 mg/kg） was given. Their acute mortality was compared with that of control mice. The mice were pre-treated with TP （100, 200, and 400 mg/kg per day） for five days before paracetamol （500 mg/kg） was given. Hepatic CYP2E1 and CYPIA2 protein and mRNA expression levels were evaluated by Western blotting, immunohistochemical staining and transcriptase-polymerase chain reaction. RESULTS： The hepatic CYP450 and CYPb5 levels in mice of TP-treated groups （100, 200 and 400 mg/kg per day） were decreased in a dose-dependent manner compared with those in the negative control mice.TP significantly attenuated the paracetamol-induced hepatic injury and dramatically reduced the mortality of paracetamol-treated mice. Furthermore, TP reduced CYP2E1 and CYPIA2 expression at both protein and mRNA levels in a dose-dependent manner. CONCLUSION： TP possess potential hepatoprotective properties and can suppress CYP450 expression.展开更多
基金Grant from the Science Foundation of Educational Department of Liaoning Province,05L117Dalian Science&Technology Bureau,2007J22JH012
文摘AIM： To investigate the hepatoprotective activity of tea polyphenols （TP） and its relation with cytochrome P450 （CYP450） expression in mice. METHODS： Hepatic CYP450 and CYPbs levels were measured by UV-spectrophotometry in mice 2 d after intraperitoneal TP （25, 50 and 100 mg/kg per day）. Then the mice were intragastricly pre-treated with TP （100, 200 and 400 mg/kg per day） for six days before paracetamol （1000 mg/kg） was given. Their acute mortality was compared with that of control mice. The mice were pre-treated with TP （100, 200, and 400 mg/kg per day） for five days before paracetamol （500 mg/kg） was given. Hepatic CYP2E1 and CYPIA2 protein and mRNA expression levels were evaluated by Western blotting, immunohistochemical staining and transcriptase-polymerase chain reaction. RESULTS： The hepatic CYP450 and CYPb5 levels in mice of TP-treated groups （100, 200 and 400 mg/kg per day） were decreased in a dose-dependent manner compared with those in the negative control mice.TP significantly attenuated the paracetamol-induced hepatic injury and dramatically reduced the mortality of paracetamol-treated mice. Furthermore, TP reduced CYP2E1 and CYPIA2 expression at both protein and mRNA levels in a dose-dependent manner. CONCLUSION： TP possess potential hepatoprotective properties and can suppress CYP450 expression.
