Lowering of plasma LDL cholesterol in hamsters by the tomato glycoalkaloidtomatine

Tomatoes contain the steroidal glycoalkaloid tomatine, which has been repor ted to form strong, insoluble complexes with cholesterol in vitro. To deter mine whether tomatine can reduce dietary cholesterol absorption and plasma levels of cholesterol and triglycerides, we fed hamsters a high-fat, high-c holesterol diet with 0.05-0.2% added tomatine in the diet. The tomatine die ts induced lowering of serum low-density lipoprotein (LDL) without changing high-density Lipoprotein (HDL) cholesterol. Compared to the control diets, four- to fivefold more labeled dietary cholesterol and coprostanol was exc reted in the feces of the tomatine-fed hamsters. The amount of cholesterol excreted in the feces corresponded to the amount of tomatine in the diet. T hese observations suggest that due to the formation of an insoluble tomatin e-cholesterol complex and its excretion in the feces, very little dietary t omatine is absorbed from the digestive tract into the blood stream. They ar e also consistent with the reported low oral toxicity of tomatine compared to other glycoalkaloids. Published by Elsevier Science Ltd.