DPPH Free Radical Scavenging Activity of Ethanolic Extracts of Twenty Two Medicinal Species from South Algeria (Laghouat Region)

Free radicals scavenging Activity, total phenolic and flavonoids contents of Twenty two ethanolic extracts, from the botanical families Asteraceae, Lamiaceae, Amaranthaceae, Chenopodiaceae, Cupressaceae, Ericaceae and Rhamnaceae, collected from the Laghouat region (Algeria Sahara) were investigated. The 2,2-diphenyl-1- picrylhydrazyl radical assay was used to determine the antioxidant activity of the plant extracts, while the Folin– Ciocalteu method was used to determine the total phenolic content and flavonoids using AlCl3 method. The antioxidant capacity expressed as IC50 values ranged from 20 µg/ml for O. basilicum to 650 ± 8.60 µg/ml for A. iva. The total phenolic content ranged from 2.72 to 87.11 mg/g of dry weight of extract, expressed as gallic acid equivalents. The total flavonoid concentrations varied from 1.48 to 12.59 mg/g, expressed as rutin equivalents. The results of this study showed that there is no significant correlation between antioxidant activity and phenolic content of the studied plant materials and phenolic content could not be a good indicator of antioxidant capacity