Effect of curcuma xanthorrhiza (ROXB.) on plasma and liver cholesterol and triglyceride in mice

Abstract

The hypocholesteremic effect of Curcuma xanthorrhiza which is an indigenous plant of our country was investigated in mice. Two extracts which were the hexane and ethyl acetate extracts obtaining from a successive extraction process were employed. Twenty four house after an oral administration of the extracts at various doses (10-1500 mg/kg BW), the plasma levels of triglyceride was decreased, whereas the liver triglyceride content and liver weight were increased. Changes of these three parameters shoed a dose-dependent effects. The hexane extract had ability to lower only plasma triglyceride whereas the ethyl acetate extract could lower both plasma triglyceride and cholesterol. The effective dose of the ethyl acetate extract in lowering plasma cholesterol was at 500 mg/kg BW. It lowered tha plasma cholesterol from 157.6±1.1 mg% in control to 123.9±5.3 mg%. Neither higher dose of drug nor a prolonged period of treatment could further lower down the plasma cholesterol level. The lower plasma cholesterol by the extract occurred without any significant change of liver cholesterol content. The plasma level of enzyme GOT as well as GPT and protein contents in the liver homogenate were not affected by the ethyl acetate extract which suggested that the extract did not damage the liver cell. To investigate the possible mechanism responsible for hypocholesteremic effect of the ethyl acetate extract, the excretion of cholesterol and bile salt in feces and the cholesterol-transported lipoprotein (HDL-cholesterol) were determined. After administration of C. xanthorrhiza extract, the lowered plasma cholesterol was accompanied by an elevation of fecal cholesterol and bile salt output. This elevation persisted throughout the period of treatment and the level declined after withdrawal from the treatment. Changes of plasma cholesterol and fecal cholesterol levels were returned back to control levels by 6 days after withdrawal from the treatment. These results suggested that C. xanthorrhiza exerted hypocholesteremic effect by enhance excretion of cholesterol and bile salt into feces. As the cholesterol high density lipoprotein (HDL) was found to be increased by C. xanthorrhiza, an accelerated cholesterol mobilization from peripheral tissue storage was suggested. Therefore, hypocholesteremic action of the ethyl acetate extract of C. xanthorrhiza was suggested to associate with an acceleration of cholesterol mobilization from plasma and tissue and enhance its excretion through bile into feces as the cholesterol itself and after conversion to bite salt.