Gastrointestinal activity of saponins from soy and tomato

Saponins, a structurally diverse family of secondary plant metabolites, possess anti-carcinogenic, hypolipemic, hypocholesterolemic, and immune-enhancing activities. We have initiated studies comparing the effects of saponins extracted from several sources soy and a commercial mixture of phytosterols (positive control) on GI metabolism and transport of cholesterol and on interactions between gut microbes and intestinal epithelial cells. Saponins from tomato reduced the incorporation of cholesterol into synthetic micelles by 60%, whereas other test compounds (saponins from soya, chickpea and fenugreek and phytosterols) were without effect. During simulated gastric and small intestinal digestion, saponins (90 µM) from tomato and mixed phytosterols significantly inhibited micellarization of cholesterol (14 µM) from a food matrix. Saponins from soy and tomato, as well as phytosterols, also significantly impaired the micellar transfer of cholesterol into differentiated cultures of human intestinal Caco-2 cells. Additionally, soyasaponins decreased adherence and invasion of Caco cells by Salmonella enterica. These preliminary observations suggest that saponins from crops important to Ohio’s economy may contribute to cardiovascular and gastrointestinal health. Supported by OARDC and USDA BARD grant. Abstract was reviewed by M. Failla, Ms. Carlson’s advisor (failla.3@osu.edu)OARDCUSDA BARD gran