The effects of Coptidis Rhizoma extract on a hypercholesterolemic animal model

The serum cholesterol (total, free, esterified, low density lipoprotein (LDL) and oxidized LDL) levels of rats fed a diet containing, by weight, 1% cholesterol and 0.5% cholic acid increased, as compared with those of rats fed a normal diet. The levels, especially of total cholesterol, LDL and oxidized LDL, were reduced significantly in a dose-dependent manner, in rats given Coptidis Rhizoma extract orally at doses of 50 and 100 mg/kg body wt./day for 30 days. These results indicate that Coptidis Rhizoma extract is effective in reducing the pathological damage caused by hypercholesterolemia, through lowering of serum cholesterol levels. In addition, Coptidis Rhizoma extract reduced the level of liver cholesterol, but it did not reduce that of fecal cholesterol, suggesting that the cholesterol level-lowering effect resulted from the reduction of cholesterol synthesis, not the enhancement of its excretion. Furthermore, the serum thiobarbituric acid-reactive substance level decreased after oral administration of Coptidis Rhizoma extract, indicating that Coptidis Rhizoma could prevent hypercholesterolemic disease through reducing lipid peroxidation. This study demonstrates that Coptidis Rhizoma may be a useful therapy for hypercholesterolemia through reducing oxidative stress and cholesterol levels.