Hepatoprotective potential of Tecomella undulata stem bark is partially due to the presence of betulinic acid

Ethnopharmacological relevance: Tecomella undulata (TU;' Family Bignoniaceae) is used in Indian Ayurvedic system of medicine for treating various diseases including hepatic ailments. It is also incorporated in various marketed hepatoprotective polyherbal formulations. Aim: The present study was aimed at evaluating possible hepatoprotective role of isolated compounds from TU stem bark (TSB) using in vitro and in vivo experimental models. Methods: In vitro cytotoxicity and hepatoprotective potential of various extract, fractions and isolated compounds from TU stem bark were evaluated using HepG2 cells. Rats were pre-treated with TU methanolic extract (TSB-7) or betulinic acid (MS-2) or silymarin for 7 days followed by a single dose of CCl₄ (0.5 ml/kg, i.p.). Plasma markers of hepatic damage, hepatic antioxidants and indices of lipid peroxidation along with microscopic evaluation of liver were assessed in control and treatment groups. Results: TSB-2 and MS-1 accounted for significant cell death whereas; TSB-1, TBS-7, TSB-9, TSB-10 and, MS-2 did not register significant cytotoxicity. Further, non-cytotoxic components exhibited ascending grade of hepatoprotection in vitro (TSB-10<TSB-1<TSB-7<TSB-9<MS-2). Pre-treatment of TSB-7 or MS-2 to CCl₄ treated rats prevented hepatocyte damage as evidenced by biochemical and histopathological observations. Conclusion: It can be concluded that, hepatoprotective potential of Tecomella undulata stem bark is partially due to the presence of betulinic acid.