Acanthopanax senticosus was grown by a novel, proprietary method, of culturing isolated cells in a bioreactor. An extract from the cells was evaluated for its effect on lipid metabolism in rats fed a high fat diet. Male Sprague-Dawley rats (n＝6) were fed either an AIN-76 diet (control, NDCon), control diet plus Acanthopanax senticosus extract (ND＋Ex), a modified AIN-76 diet supplemented with 20% beef tallow (high fat, HFCon), or a high fat diet plus Acanthopanax senticosus extract (HF＋Ex), for 5weeks. Body weight gain was significantly higher in the HFCon group than the NDCon group. Feed consumption was significantly lower, but energy intake higher, in the groups fed high fat diets compared with the groups fed control diets. Serum HDL-cholesterol concentrations were significantly increased but serum LDL-cholesterol concentrations were decreased in the groups fed the Acanthopanax senticosus extract. Abdominal fat accumulation and serum leptin levels were significantly higher in the HFCon group than the other groups. Carnitine palmitoyltransferase-I (CPT-I) mRNA levels were increased in the groups fed Acanthopanx senticosus extract. These results suggest that supplementation of cell cultured Acanthopanax senticosus extract regulates CPT-I mRNA levels in liver and has an effect on the normalization of lipids in rats fed a high fat diet.