Mechanisms of Inhibition of Cholesterol Absorption by Green Tea Catechins

Several studies have shown that green tea catechins reduce serum and liver cholesterol concentrations and increase the fecal excretion of neutral steroids originating from cholesterol in experimental animals. Furthermore, we have found that green tea catechins, particularly, their galloyl esters, could reduce the lymphatic absorption of cholesterol in rats. This finding suggests that green tea catechins having a galloyl moiety can inhibit cholesterol absorption in the intestine, thus reducing serum cholesterol concentration. The solubilization of cholesterol in bile salt micelles is essential for its absorption. Catechins having a galloyl moiety can decrease the micellar solubility of cholesterol; however, it is not well understood how these catechins decrease micellar solubility. This review presents novel mechanisms underlying the decrease in cholesterol micellar solubility mediated by catechins having a galloyl moiety.