Antioxidant, DNA protective and antibacterial activities of Terminalia bellerica extracts

Terminalia bellerica Roxb., commonly known as Beleric myrobalan, is a well-known large deciduous tree with various pharmaceutical properties. However, scientific information on T. bellerica, growing in India, as regards to its phytochemical constituents and pharmacological properties is very limited. With this in view, this study investigated the antioxidant, DNA protective and antibacterial activities of different parts (fruit pulp, seed and bark) of T. bellerica. Methanol (70%) and water (100% distilled water) were used for the extraction and analysis of total phenolic contents (TPC). Plant extracts were further screened for antibacterial activity against both gram (+) and gram (-) bacteria and minimum inhibitory concentration (MIC) values were calculated. Amongst the tested extracts, methanolic extract contained more TPC than aqueous extract. Methanolic fruit pulp (MEFP) showed lower IC50 (118.7 µg/ml) for free radical, (77.65 µg/ml) superoxide anion radical, (73.76 µg/ml) hydroxyl radical scavenging activity, (115.6 µg/ml) lipid peroxidation and (184.98 µg/ml) ferric thiocyanate assay. Methanolic extract also exhibited more potential DNA protective and antibacterial activity than aqueous extract. Furthermore, the correlation between TPC and antioxidant studies revealed that phenolics are mainly responsible for antioxidant, DNA protective and antibacterial activities of T. bellerica. This study suggests that the methanolic extract of T. bellerica could be a potential source of natural antioxidants. Key words: Terminalia bellerica, antioxidative, DNA protective, antibacterial.