RESUMO
On analysing the effect of catechin on intestinal lipid metabolism, an increase in the concentration of cholesterol in the duodenum and jejunum was observed along with an increase in the HMGCoA reductase activity. In the in vitro experiments also it was found that cholesterol and free fatty acid (FFA) levels were increased in these two regions. Binding of catechin with cholesterol in the lumen, reduces the availability of cholesterol for absorption which may in turn stimulate cholesterol biosynthesis and a rise in the HMGCoA reductase activity. These alterations produced by catechin may also be related to the degradation of cholesterol to bile acids, as endogenous cholesterol is the preferred substrate for bile acid synthesis.
Assuntos
Animais , Radioisótopos de Carbono/diagnóstico , Catequina/farmacologia , Colesterol/metabolismo , Glucose/metabolismo , Hidroximetilglutaril-CoA Redutases/metabolismo , Intestinos/efeitos dos fármacos , Metabolismo dos Lipídeos , Masculino , Fosfolipídeos/metabolismo , Ratos , Ratos Sprague-Dawley , Triglicerídeos/metabolismoRESUMO
Effect of varying concentrations of catechin on blood glucose levels was examined in male rats. Catechin exerted maximum hypoglycemic action at a dose of 10 mg/kg BW/day. Above this dose, the activity decreased gradually and blood sugar returned to almost normal levels at a concentration of 100 mg/kg BW/day. At optimum dose of catechin there was increase in the hepatic glycogen levels. Incorporation of [14C] glucose into glycogen in vitro was also increased. Glycogen synthase activity was found increased significantly whereas glycogen phosphorylase showed a decrease showing that hypoglycemic effect of catechin is due to increased glycogenesis and decreased glycogenolysis.