Chemical composition, antioxidant and hepatoprotective activities of methanol extracts from leaves ofTerminalia belliricaandTerminalia sericea(Combretaceae)

Abstract

BackgroundPlants belonging to the genusTerminaliasuch asTerminalia belliricaandTerminalia sericeaare used traditionally to treat several diseases and health disorders. Up to this date, the roots ofTerminalia sericeaand the fruits ofTerminalia belliricaare the mostly studied plant parts. The phytochemical composition and the biological activities of the leaves of both species are not well identified so far.MethodsThe secondary metabolites ofTerminalia belliricaandTerminalia sericealeaves were identified using HPLC-PDA-MS/MS. The antioxidant activities of the leaves extracts were determined by DPPH and FRAP assays. The hepatoprotective potential was evaluated in rats with D-galactosamine induced liver damage. The effect of the extracts on the expression of the anti-apoptotic marker Bcl-2 was measured in an immunohistochemical study. The most abundant compounds identified in the studied extracts were docked into Bcl-2: Bim (BH3) interaction surface using molecular operating environment software.ResultsA total of 85 secondary metabolites were identified in the leaf extracts of both species. Ellagitannins such as corilagin, chebulagic acid, galloylpunicalagin, and digalloyl-hexahydroxydiphenoyl-hexoside were found to be the major components inTerminalia belliricawhereas flavonoid glycosides including quercetin rutinoside and quercetin galloyl-glucoside were highly abundant inTerminalia sericea. The studied extracts exhibited pronounced antioxidant activities, moderate anti-apoptotic and hepatoprotective potential. In silico docking experiments revealed that the compounds abundant in the extracts were able to bind to Bcl-2: Bim (BH3) interaction surface with an appreciable binding free energy.DiscussionThe antioxidant and hepatoprotective activities exhibited by the studied extracts might be attributed to the high content of the polyphenols. The anti-apoptotic activity could be due to the interference with the apoptotic pathway mediated by Bcl-2: Bim interaction. These findings support the medicinal relevance ofTerminalia belliricaandTerminalia sericeaand provide a rational base for their utilization in folk medicine.