Interactions of alfalfa plant and sprout saponins with cholesterol in vitro and in cholesterol-fed rats

Abstract

The in vitro interactions of saponins from alfalfa plant and alfalfa sprouts with cholesterol and the effects of alfalfa plant and sprout and saponin-free alfalfa plant on diet-induced liver cholesterol accumulation, bile acid excretion, and jejunal and colonic morphology were examined. Cholesterol-saponin interactions have been suggested as mechanisms for the observed hypocholesterolemic effects of alfalfa as well as the changes in intestinal morphology. Alfalfa plant saponins bound significant quantities of cholesterol both from ethanol solution and from micellar suspension. Alfalfa sprout saponins interacted with cholesterol to a lesser but significant extent. Sprout saponins also inhibited growth of Trichoderma viride significantly, another measure of saponin-cholesterol interaction. Bile acid adsorption was greatest for alfalfa plant and was not reduced by removal of saponins from the plant material. The ability of alfalfa to reduce liver cholesterol accumulation in cholesterol-fed rats was enhanced by removal of saponins and alfalfa sprouts did not prevent accumulation. Removal of saponins from alfalfa reduced the changes in intestinal morphology previously reported, but interaction with membrane cholesterol did not appear to be the cause of this effect of saponins. Saponin-cholesterol interaction is an important part of the hypocholesterolemic action of alfalfa but interaction of bile acids with other components of alfalfa may be of equal importance.

Biological Effects of Feed and Forage Saponins and Their Impacts on Animal Production

“…These enhanced nutrient losses could partially account for the growth-decreasing effects of saponins. Story et al (1984) noted damage to the intestinal villi of rats fed alfalfa, while. the lesions were less severe in rats fed saponin-free alfalfa.…”

Phytochemical and pharmacological potential ofMedicago sativa: A review

“…Hypocholesterolemic activity has been reported for root saponins, when given to monkeys receiving a high-cholesterol diet (Malinow et al, 1977b) In a study, the ability of M. sativa plant to reduce liver cholesterol accumulation in cholesterol-fed rats was enhanced by the removal of saponins. Therefore, M. sativa saponins appear to play an important role in neutral steroid excretion, but are not essential for increasing bile acid excretion (Story et al, 1984). In an experiment with prairie dogs, the lowest incidence of cholesterol gallstones was served with the diet of the higher fiber content (85% alfalfa) (Cohen et al, 1990).…”

Effects of a Purified Saponin Mixture from Alfalfa on Plasma Lipid Metabolism in Hyperlipidemic Mice

“…3,4) Many studies proved that saponins are the main active compounds in alfalfa. 5,6) However, the relatively low content of saponins in alfalfa extracts leads to the decrease of hypolipidemic activities, and results in the unavailable medicinal and clinical usages. In this study, we obtained a purified saponin # These authors contributed equally to this work.…”