Potentiation of anti-cholelithogenic influence of dietary tender cluster beans (Cyamopsis tetragonoloba) by garlic (Allium sativum) in experimental mice

BACKGROUND & OBJECTIVES: Dietary fibre-rich tender cluster beans (Cyamopsis tetragonoloba; CB) are known to exert beneficial cholesterol lowering influence. We examined the influence of a combination of dietary tender CB and garlic (Allium sativum) in reducing the cholesterol gallstone formation in mice. METHODS: Cholesterol gallstones were induced in Swiss mice by feeding a high-cholesterol diet (HCD) for 10 wk. Dietary interventions were made with 10 per cent CB and 1 per cent garlic included individually or together along with HCD. A total of 100 mice were divided into five groups of 20 mice each. RESULTS: Dietary CB, garlic and CB+garlic reduced the formation of cholesterol gallstones by 44, 25 and 56 per cent, respectively, lowered cholesterol by 23-48, 16-24, and 24-58 in bile, serum, and liver, respectively. Cholesterol saturation index in bile and cholesterol: phospholipid ratio in circulation and hepatic tissue were significantly lowered by these dietary interventions, with highest beneficial effect from CB+garlic. Activities of hepatic cholesterol metabolizing enzymes were modulated by CB, garlic and CB+garlic. Elevation in lipid peroxides caused by HCD was also countered by these dietary interventions, the combination producing the highest effect. INTERPRETATION & CONCLUSIONS: The results showed that the prevention of experimentally induced formation of cholesterol gallstones by dietary CB and garlic was due to decreased biliary cholesterol secretion and increased cholesterol saturation index. In addition of anti-lithogenic effect, dietary CB and garlic in combination had a beneficial antioxidant effect.