FREE RADICAL SCAVENGING ACTIVITIES OF ZIZYPHUS MA URITIANA

In the present study, antioxidant activities of the two varieties of fruits of Zizyphus mauritiana (Boroi) were investigated. For this, at first matured fruits of them were sliced into small pieces and dried in the sun and finally crushed it in grinder to make powder. Ethanolic extracts of fruits powder were prepared using 99.99% ethanol. The resulting extracts were characterized by the method described by Hatano et al. (1988) in which stable 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical is recommended to use. 1ml of each solution of different concentrations (1-500 |ig/ml) of the extracts was added to 3 ml of 0.004% ethanolic DPPH free radical solution. After 30 minutes, the absorbances of the preparations were taken at 517 nm by a UV spectrophotometer which was compared with the corresponding absorbance of standard ascorbic acid concentrations (1-500 |ig/ml). The IC50 (Inhibition concentration) was determined by the absorbance which denotes the concentration of sample required to scavenge 50% of the DPPH free radicals (Gupta et al., 2003). In this investigation, it was found that all of the fruit extracts have remarkable antioxidant activities. The IC50ʹs of the ethanolic extracts of Zizyphus mauritiana (Local) and Z. mauritiana (Narikeli kul) were 72 and 250 |ig/ml respectively. Between these two varieties local variety showed higher antioxidant activities. Therefore, local variety of Zizyphus mauritiana is very beneficial for human health.