Failure of the non vitamin A active carotenoid lycopene to act as an antihypercholesterolemic agent in rats

Pharmacological levels of vitamin A have been shown to retard the accumulation of cholesterol in the serum and liver of several different species of experimental animals. Recently, β carotene has also been shown to decrease serum cholesterol in hypercholesterolemic rats. The object of the present study was to determine if lycopene, an opened ringed carotenoid with no vitamin A activity, would prevent hypercholesterolemia in the rat. Several levels of lycopene from 78 to 3813 μg/day were fed for 28 days to male weanling rats consuming a vitamin A deficient 1% cholesterol diet. The resultant serum, liver and chilesterol levels were compared to the response of animals consuming a vitamin A deficient 1% cholesterol control diet (OA Chol) and a vitamin A deficient control diet (OA). All dietary lycopene levels, exept 1640 μg/day, resulted in an increased (P<0.05) serum cholesterol when compared to the OA diet. Vitamin A at 1985 μg/day or 1916 μg/day of β carotene under the same conditions significantly reduced (P<0.05) serum cholesterol in hypercholesterolemic rats. These results add support to the hypothesis that vitamin A activity may be of importance in the pathogenesis of hypercholesterolemia.