Antioxidant activity, total phenolic and flavonoid content variation among Tunisian natural populations of Rhus tripartita (Ucria) Grande and Rhus pentaphylla Desf.

Abstract

The antioxidant activity, total phenolic and flavonoid contents of methanolic extracts from different plant parts of Tunisian Rhus tripartita (Ucria) and R. pentaphylla Desf. populations were determined. The total phenolic content in stem cortex was higher than that of the other plant parts with the highest content in R. tripartita. Flavonoids were more represented in leaf and fruit extracts of R. pentaphylla.Antioxidant activity, determined by DPPH and FRAP assays, was high. The highest activity was found in stem cortex extract from both species with the lowest in R. pentaphylla. A significant correlation between antioxidant activity and phenolic content was revealed. PCAs performed on compound contents or antioxidant activities of all extracts did not reveal clear groupings of populations according to their bioclimatic zone. The global divergence among populations seems to be linked to altitudes and geographic distances. Based on their phenolic contents and antioxidant activity several populations from each species could be used as starting material to develop sustainable production. Conservation strategies of the populations should be made appropriately within their bioclimatic zones in respect to geographic location.