Comparative analysis of phytochemicals, in vitro antimicrobial and in vitro antidiabetic activity of different parts of Terminalia bellerica fruits.

Abstract

Terminalia bellerica which is also known as baheda or bahera it is one of the most deciduous trees in the Combretaceae family. It is used for preparation of triphala, an Indian herb. The present study was aimed to compare phytochemicals, antimicrobial activity and antidiabetic activity activities in pulp, seed and seedcoat of T. bellerica collected from Mohali, Punjab. Extract of different solvents, viz., hexane, methanol and aqueous were prepared using cold maceration method. Preliminary phytochemical analysis revealed the presence of most of the phytochemicals in all the parts, however, alkaloids were absent in all solvent extracts of seeds. Phenols were found to be absent in hexane extract of pulp and seed. Total phenolic content was found to be highest in aqueous extract of seed coat (154.22±2.33 mg/g GAE) and methanol extract of seed (119.06±6.65 mg/g GAE). Among all extracts, methanolic extract of seed coat showed lowest MIC (3.125 µg/ml) against both tested gram-positive bacteria (B. subtilis, and S. aureus), while, methanolic pulp extract was found to be more effective against K. pneumoniae and P. aeruginosa with MIC of 3.125 µg/ml. Hexane extract of pulp showed higher inhibitory activity against E. coli with least MIC (3.125 µg/ml). Aqueous extract of seed coat showed strong in vitro anti-diabetic activity with IC₅₀ value of 3.92 µg/ml as compared to that of standard drug, metformin (14.5 µg/ml). The results of the present study showed therapeutic applications of seed coat of T. bellerica fruits. However, further studies need to isolate the phytocompounds responsible for their biological activities.