The hypocholesterolemic effects of Cistanche tubulosa extract, a Chinese traditional crude medicine, in mice.

The roots of Cistanche (C.) tubulosa (Orobanchaceae), a parasitic plant that grows in the Taklamakan desert, are traditionally used as medicines and foods in China. We prepared aqueous ethanol extract (CTE) from the roots of C. tubulosa and its hypocholesterolemic effect was evaluated. Using gene chip and RT-PCR analysis of the livers of mice given CTE (400 mg/kg) for 14 days, we found mRNA expression of molecules related to cholesterol transport [apolipoprotein B and very low density lipoprotein (VLDL) receptor] and metabolism [cytochrome P450 side chain cleave (SCC) and steroid 5alpha-reductase 2] were up-regulated. The administration of CTE (400 mg/kg) for 14 days significantly suppressed serum cholesterol elevation in high cholesterol diet-fed mice. The mRNA expressions of VLDL receptor and cytochrome P450 SCC were significantly enhanced. In addition, acteoside, a major constituent of CTE, was found to enhance the mRNA expressions of apolipoprotein B, VLDL receptor, and cytochrome P450 SCC in HepG2 hepatocytes. These results suggest that CTE affects the mRNA expressions of molecules related to cholesterol transport and metabolism and exhibits hypocholesterolemic activity in diet-induced hypercholesterolemia mice. Acteoside was involved in the hypocholesterolemic activity of CTE.