Determination of Total Phenolic Content and Antioxidant Activity of Ethanol Extracts from Aloe spp.

Abstract

The ethanol extracts of leaf peel and gel of Aloe spp. were analyzed for their total phenolic and flavonoid profiles and screened for their antioxidant activity. The total phenolic content of the three different plant extracts and one commercial product of Aloe vera was determined by Folin-Ciocalteu method and flavonoid content was assessed by AlCl₃ method. Peel extract had the highest total phenolic content (7.99 mg gallic acid equivalents (GAE)/g extract) and flavonoid content (9.17 mg quercetin equivalents (QE)/g extract). The lowest content of phenolic and flavonoid compounds was observed in Soxhlet extract of Aloe gel. The in vitro antioxidant activity determined by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid (ABTS) assays revealed that all extracts exhibited low antioxidant activity compared to quercetine and thymoquinone as standards. The best antioxidant activity had the peel extract what is in correlation with content of phenolic and flavonoid compounds.