Raghavendra Chikkanna K, Srinivasan Krishnapura
Department of Biochemistry and Nutrition, CSIR - Central Food Technological Research Institute, Mysore 570 020, India.
Department of Biochemistry and Nutrition, CSIR - Central Food Technological Research Institute, Mysore 570 020, India.
Steroids. 2015 Feb;94:21-30. doi: 10.1016/j.steroids.2014.12.003. Epub 2014 Dec 19.
Tender cluster beans (CBs; Cyamopsis tetragonoloba) are observed to possess anti-lithogenic potential in experimental mice. Formation of cholesterol gallstones in gallbladder is controlled by procrystallizing and anticrystallizing factors present in bile in addition to supersaturation of cholesterol. This study aimed at evaluating the influence of CB on biliary glycoproteins, low molecular weight (LMW) and high molecular weight (HMW) proteins, cholesterol nucleation time, and cholesterol crystal growth in rat hepatic bile. Groups of rats were fed for 10 weeks with 0.5% cholesterol to render the bile lithogenic. Experimental dietary interventions were: 10% freeze-dried CB, 1% garlic powder or their combination. Incorporation of CB into HCD decreased the cholesterol saturation index in bile, increased bile flow and biliary glycoproteins. Dietary CB prolonged cholesterol nucleation time in bile. Electrophoresis of biliary proteins showed the presence of high concentration of 27 kDa protein which might be responsible for the prolongation of cholesterol nucleation time in the CB fed group. Proteins of 20 kDa and 18 kDa were higher in CB treated animals, while the same were less expressed in HCD group. Biliary proteins from CB fed animals reduced cholesterol crystal growth index which was elevated in the presence of proteins from HCD group. Cholesterol-7α-hydroxylase and cholesterol-27-hydroxylase mRNA expression was increased in CB treated animals contributing to the bile acid synthesis. Thus, the beneficial anti-lithogenic effect of dietary CB which primarily is due to reduced cholesterol saturation index was additionally affected through a modulation of the nucleating and anti-nucleating proteins that affect cholesterol crystallization.
观察到嫩的四棱豆（CBs；瓜尔豆）在实验小鼠中具有抗结石形成的潜力。胆囊中胆固醇胆结石的形成除了受胆汁中胆固醇的过饱和影响外，还受胆汁中促结晶和抗结晶因子的控制。本研究旨在评估四棱豆对大鼠肝胆汁中胆汁糖蛋白、低分子量（LMW）和高分子量（HMW）蛋白、胆固醇成核时间以及胆固醇晶体生长的影响。将大鼠分组，用0.5%胆固醇喂养10周以使胆汁具有致石性。实验性饮食干预包括：10%冻干四棱豆、1%大蒜粉或它们的组合。在高胆固醇饮食中加入四棱豆可降低胆汁中的胆固醇饱和指数，增加胆汁流量和胆汁糖蛋白。饮食中的四棱豆可延长胆汁中胆固醇的成核时间。胆汁蛋白的电泳显示，在喂食四棱豆的组中存在高浓度的27 kDa蛋白，这可能是胆固醇成核时间延长的原因。在经四棱豆处理的动物中，20 kDa和18 kDa的蛋白含量较高，而在高胆固醇饮食组中表达较少。喂食四棱豆的动物的胆汁蛋白降低了胆固醇晶体生长指数，而在高胆固醇饮食组蛋白存在的情况下该指数升高。经四棱豆处理的动物中胆固醇7α-羟化酶和胆固醇27-羟化酶的mRNA表达增加，有助于胆汁酸的合成。因此，饮食中四棱豆有益的抗结石形成作用主要归因于降低的胆固醇饱和指数，此外还通过调节影响胆固醇结晶的成核和抗成核蛋白而受到影响。
