ANTIOXIDANT ACTIVITY AND QUANTIFICATION OF PHENOLIC COMPOUNDS OF EUPHORBIA ECHINUS

摘要

Objective: Plant phenolic metabolites are gaining interest due to their potential to improve human health. One of the most important properties of these secondary metabolites is their antioxidant capacity. In this present study, we aimed to evaluate total phenolics, flavonoids, proanthocyanidins content and antioxidant activity of Euphorbia echinus. Moreover the effect of solvent (methanol and water) and temperature was investigated. Methods: Euphorbia echinus was used as a plant material which was subjected to a decoction, maceration (with both water and methanol) and soxhlet extraction. Ferric reducing/antioxidant power (FRAP) and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging tests were investigated to evaluate antioxidant activity. Folin-Ciocalteu reagent serves to determine total phenolic content, aluminium trichloride method for flavonoids and a mixture of vanillin and hydrochloric acid for proanthocyanidins; employing colorimetric method. Results: This study revealed that methanol when combined with temperature was the best solvent to take out polyphenols (21.53±1.03 mgGAE/gE) and proanthocyanidins (13.04±0.68 mgCE/gE), followed by decoction which was more efficient for flavonoids (14.31±1.02 mgRE/gE). Therefore Euphorbia echinus seems to exhibit a high radical scavenging activity; showing a low IC50which is approximately similar to IC50of vitamin C and trolox. In addition Euphorbia echinus methanolic extract showed a reducing power greater than standards. These capacities have a linear relationship with the larger quantity of antioxidant compounds. Conclusion: The results of the present study suggest that Euphorbia echinus contained potential antioxidant bioactive compounds that could serve as therapeutic agent in preventing diseases caused due to oxidative stress