Özet:

Hura crepitans (Sandbox tree) of the family of Euphorbiaceae has enjoyed many ethnomedicinal applications but little is known about its chemistry and pharmacology. This research reports the in vitro antioxidant activity of this plant using two different assay methods. Scavenging effect on 2, 2-diphenylpicrylhydrazyl (DPPH) radical at 517 nm and on hydroxyl radical generated by hydrogen peroxide at 285 nm in a UV-Visible spectrophotometric assay. Butylatedhydroxyanisole (BHA), vitamin C and α-tocopherol were used as reference standards. There is generally decrease in absorption of DPPH caused by the extracts. The percent inhibition of the crude extract increases with a decrease in concentration in the DPPH photometric assay. The percent inhibition of hexane, ethylacetate and butanol fractions was low except for the butanol fraction (50.7 % at 1.0 mg/ml) when compared with standards vitamin C (90.8 % at 1.0 mg/ml) and BHA (95.4 % at 1.0 mg/ml). In the hydrogen peroxide assay however, the hexane, ethylacetate and butanol fractions scavenged hydroxyl radical more effectively than the standards. The crude extract possessed maximum % inhibition in both the DPPH and hydrogen peroxide free radicals. Therefore, H. crepitans has very weak activity as a hydrogen donor but its activity as hydroxyl radical scavenger is high when compared to standards used. This study suggests that the crude and fractions obtained from H. crepitans possess antioxidant activities which can counteract or prevent oxidative damage in biological systems caused by the presence of hydroxyl radical.

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