Antioxidant Activity Assessment of Calpurnia aurea Root Extract

Abstract

Objective In Ethiopia, any part of Calpurnia aurea is used for the treatment of different ailments: to destroy lice and ticks, to relieve itches, syphilis, malaria, rabies, diabetes, hypertension, diarrhoea, leishmaniasis, trachoma, elephantiasis, fungal diseases, stomach-ache, bowel, bladder disorders and different swellings. However, despite its traditional usage as an agent, there is limited or no information regarding the antioxidant activity assay profile of the root part unlike other parts. Hence; the researcher interested to assess the in vitro antioxidant activities of the root extracts of Calpurnia aurea . Methods Calpurnia aurea root was collected from around Jimma Arjo highland, East Wollega, Western Ethiopia. The collected plant material was dried and powdered using electrical grinder and then macerated within four organic solvents: hexane (99%), chloroform (99.9%), ethanol (97%) and methanol (99.8%) according to their increasing polarity index for 72 hours with mechanical shaking within 4 hours interval in average and it was filtered through Whatman No.1 filter paper and the filtrate was dried using Rotary evaporator. The in-vitro antioxidant properties were assessed through DPPH (1,1-diphenyl-2-picrylhydrazyl) in ethanol solution both qualitatively and quantitatively. Results The ethanol extract of the root part of Calpurnia aurea has shown better antioxidant activity at 100 μg/mL (81.63%) when compared to the standard reference (ascorbic acid, 86.88%) and other extracts (chloroform, methanol, and n-hexane i.e., 71.72%, 36.40% and 26.14%, respectively) at the same concentration. Hexane root extract showed very weak or almost negligible activity. Conclusion It is evident from this study that highest the root part of the plant species has shown antioxidant potential which could be highly correlated with presence of flavonoids, tannins and phenolic compounds in general. Therefore, the root extract of Calpurnia aurea can be quantified for application in pharmaceutical industry.