RESUMO
Objective: To investigate Schima wallichii (S. wallichii) Choisy (Ternstroemiaceae) which is a well known plant of Sikkim in the Himalayan region, India. Methods: Therefore three major flavonoid enriched fractions (FPet.Ether, FChloroform and FEthylacetate) were isolated by petroleum ether chloroform and ethyl acetate successively. The reactive nitrogen species scavenging activity of the flavonoid fractions was established using biochemical assay to measure scavenging of 2, 2 diphenyl picrylhydrazyl (DPPH), nitric oxide (NO) and peroxinitrite. Results: FEthylacetate showed maximum scavenging activity: their IC50 being (7.33 ± 3.32), (7.11 ± 2.21), and (6.67 ± 2.23)μg/mL in DPPH, NO, peroxinitrite radical respectively. Presence of (57.32 ± 2.31) and (163.4 ±2.22) μg of flavonoids and phenolic compound in 1 mg of extract is assumed to be responsible for free radical scavenging activity. Conclusion: Taken together S. wallichii has potent free radical scavenging property indicating its importance in food supplement as a rich source of active flavonoid and phenolic compounds in ethyl acetate fraction which is responsible for its free radical scavenging as well as antioxidant activity.