In vitro hepatoprotective and antioxidant activities of the crude extract and isolated compounds from Irvingia gabonensis

Abstract

The in vitro hepatoprotective effect of the methanolic extract from Irvingia gabonensis (Aubry Lecomte ex O’Rorke) on CCl4induced liver cell damage as well as the possible antioxidant mechanisms involved in this protective effect were investigated. The phytochemical investigation of this methanolic extract led to the isolation of seven compounds identified as: 3-friedelanone (1); betulinic acid (2); oleanolic acid (3); 3, 3’, 4’-tri-O-trimethylellagic acid (4); methyl gallate (5); hardwickiic acid (6) and 3-β-acetoxyursolic acid (7). The hepatoprotective activity of these compounds was tested in vitro against CCl4-induced damage in rat hepatoma cells. Compounds (3), (7), (5) and (2) showed significant hepatoprotective activity as indicated by their ability to prevent liver cell death and LDH leakage during CCl4 intoxication. In addition, 2, 4-dinitrophenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, the β-Carotene-Linoleic Acid Model System (β-CLAMS), the Ferric-Reducing Antioxidant Parameter (FRAP) and microsomal lipid peroxidation assays were used to measure the antioxidant activity of the crude extract and isolated compounds. Compared with compounds (1), (2), (4), and (6), compounds (3), (5) and (7) showed significant antioxidant effects involving radicalscavenging action, inhibition of microsomal lipid peroxidation, β-CLAMS and FRAP assays. These results suggest that the protective effects of the crude extract of Irvingia gabonensis against CCl4-induced hepatotoxicity possibly involve the antioxidant effect of these compounds.