The Parasitic Plant Cistanche violacea (Desf.) Beck from Ghardaïa (Algeria): A Source of Biologically Active Compounds

Abstract

The present study aims to determine the contents of total polyphenol (TPC) and total flavonoid (TFC) and evaluate the antioxidant and antimicrobial activities of Cistanche violacea (Desf.) Beck. The extraction of bioactive compounds from the whole plant of C. violacea (Desf.) Beck was carried out by three different methods, including maceration, Soxhlet, and ultrasound, with ethanol and water as solvents. The results showed that the ultrasound ethanolic extract recorded the greatest amounts of TPC with 188.95 ± 2.2μg gallic acid equivalent/mg dry extract, while for TFC, it was the maceration ethanolic extract with 40.26 ± 6.02µg quercetin equivalent/mg dry extract. The High-Performance Liquid Chromatography (HPLC) results showed the presence of phenolic compounds, with 32 identified compounds in the ethanolic and aqueous extracts. The different extracts showed antioxidant capacities for DPPH, ABTS, phenanthroline, and reducing power assays. The highest antioxidant ability was observed with the ethanolic extract obtained by the maceration method (IC50 33.35 ± 1.4 and IC50 < 12.5 μg/mL for DPPH and ABTS tests). The antimicrobial investigation on seven microbial strains revealed that the ethanolic extract ultrasound showed moderate antibacterial activity (18.66 ± 1.1mm) against only Staphylococcus aureus ATCC25923, while the other extracts showed weak or no antimicrobial activity. This work suggests that C. violacea (Desf.) Beck has antioxidant properties of natural origin, which justify its traditional use in treating many conditions related to oxidative stress.