Impact of Extraction Solvent Polarity: Antioxydant Activity of Methanolic, Hydromethanolic and Aqueous Decocted Extracts of Algerien Thymelaea hirsuta (L.) Endl. Areal Parts

Abstract

Thymelaea hirsuta (L.) Endl. , known as ‘Methnane’ in Algeria, is a widely medicinal plant used in folk medicine. In the present study, In vitro antioxidant activity of T. hirsta extracts and the impact of extraction solvent polarity on the antioxidant potential were investigated. Three types of polar solvents with decreasing polarity were chosen; water for decocted extract, methanol-water at 50% and absolute methanol for macerated extracts. Total phenolic and flavonoid contents were evaluated and showed a high amount wihch decreases with increasing polarity. Antioxydant activity was assessed with different methods: ABTS assay for evaluation of scavenge activity, CUPRAC and reducing power for assessement of the reduction potential of T. hirsuta areal parts. The results showed that T. hirsuta areal parts exhibited a strong scavenging activity with significant difference between extracts in terms of their polarity. In the same line, the most polar aqueous decocted extract exhibited a considerable reducing activity followed by hydromethanolic and methanolic extract with increasing potential. These findings suggest the suitability of polar solvents for the extraction of phytochemical compounds from T. hirsuta areal parts and so, their antioxidant activity against several radicals and ions.

Keywords

• Thymelaea hirsuta
• antioxidant
• solvent polarity
• reducing power.