IN VITRO ANTIOXIDANT ACTIVITIES OF Aloe vera LEAF SKIN EXTRACTS

The ethanolic extract of Aloe vera leaf skin was fractionated by liquid-liquid partition using hexane, ethyl acetate, chloroform-ethanol and butanol. The total phenolic content of the four different fractions were determined by Folin-Ciocalteu method and their antioxidant activity was essayed through some in vitro models such as the antioxidant capacity by phosphomolybdenum method, β-carotene bleaching method, radical scavenging activity using 2,2-diphenyl-1-picryl hydrazyl (DPPH) assay and reducing power assay. The chloroform-ethanol fraction showed the highest total phenolics (40.500 ± 0.041 μg gallic acid equivalents/g of extract), the highest scavenging activity and the greatest reducing power, followed by ethyl acetate, butanol and hexane extracts. However, the hexane fraction showed the highest antioxidant capacity (471.300 ± 0.013) and the highest antioxidant activity coefficient (AAC) by the βcarotene bleaching method.