Phytochemical composition and antioxidant properties of prickly pear (Opuntia ficus-indica L.) flowers from the Algerian germplasm

Prickly pear Opuntia ficus-indica L. is a widely used plant in traditional medicines and as edible food product mainly in arid regions. Its phytochemical properties are primarily due to secondary metabolites present in its different parts. Quantity and quality of different metabolites and their associated biological activities are influenced by the genetic structure of medicinal plants and environmental conditions to which plants are exposed. This study aimed to assess the aqueous extract of O. ficus-indica flowers belonging to six populations from the Algerian germplasm in terms of phenolics, flavonoids, tannins, sugars and minerals contents along with the antioxidant activity revealed by the free radical scavenging activity (DPPH) and ferric reducing power assays. Results revealed that populations from high altitudes Ain Defla', Msila' and Tiaret' were characterized by their low phenolics content along with high flavonoids and sugars contents. However, populations from low altitudes showed high contents of polyphenols and condensed tannins but less sugars. In addition, all populations demonstrated a variable antioxidant activity. Variation in antioxidant properties and bioactive compounds contents among O. ficus-indica populations must be used for harnessing the maximum potential of the species and for breeding programmes at large-scale multiplication for commercial cultivation. The obtained results demonstrated the importance of Opuntia flowers as a potential source of bioactive substances for food and medicines.