In vitro detennination of antioxidant activity of Diospyros buxifolia

Diospyros buxifolia, a member of Ebenaceae family is a tropical evergreen shrub or small tree that possesses various biological activities such as antibacterial,
anti-inflammatory and cytotoxicity activity. In the present study, the total phenolic content, total flavonoid content and antioxidative properties of leaves extracts of Diospyros buxifolia were analyzed. The antioxidant properties of the extract were determined by scavenging 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH) and ferric reducing antioxidant power (FRAP). The samples were extracted with distilled water and methanol at 40°C and 60°C which used for the evaluation of its total phenolic content, total flavonoid content and antioxidant potential. The results showed that, compared to aqueous extract, methanolic leaves extracts of Diospyros buxifolia has a higher total phenolic content at 40°C (35.43 ±0.19 mg GAE/g extract), total flavonoid content at 60°C (257.78 ± 12.62 mg CE/g extract), percentage of inhibition of DPPH radical scavenging activity at 60°C (22.31 ±1.180% at the concentration of 100 μg/mL) and FRAP value at 60°C (0.369 ± 0.036 mM/ L at the concentration of 1.0 mM). lC₅₀ values of methanolic extracts were found to be 276.30 μg/mL at 60°C for DPPH. The results showed potent antioxidant activity in all sample extract when compared with ascorbic acid which having lC₅₀ values 56.56 μg/mL for DPPH. The results obtained in the in vitro models clearly suggest that methanolic extract has higher antioxidant activity than the aqueous extract due to a higher presence of phenolic and flavonoid constituents in the methanolic extract.