Phytochemical profiling, antioxidant and antibacterial activities of phenolic extracts from Smilax aspera and Atractylis humilis roots
摘要
This study evaluates the chemical composition, the antioxidant and antimicrobial activities of phenolic extracts of Smilax aspera and Atractylis humilis roots from Algeria. The total phenolic, the flavonoid and the condensed tannin amounts were analyzed in different extracts using Folin-Ciocalteu, aluminum chloride and vanillin assays, respectively. The UHPLC-DAD-ESI-MSn analysis was used for the qualitative elucidation of bioactive compounds. The in vitro antioxidant capacity of extracts was evaluated by DPPH, iron chelating ABTS· + and FRAP assays. The different extracts were tested against five bacterial strains (Escherichia coli, Pseudomonas aeruginosa, Yersinia enterocolitica, Klebsiella pneumoniae and Staphylococcus aureus.) and one fungal strain (Candida albicans). Among the analyzed Smilax aspera and Atractylis humilis polar extracts, the ethyl acetate fraction of the S. aspera hydro-methanolic system had the highest total phenolic and flavonoid contents. UHPLC-DAD-ESI-MSn analysis revealed glycoside saponins in S. aspera and various hydroxycinnamic acid derivatives in A. humilis extracts. The ethyl acetate fraction of S. aspera hydromethanolic system extract demonstrated strong antioxidant activity (IC50 = 54.12 ± 0.74 µg/mL and 14.65 ± 0.34 µg/mL in DPPH and ABTS assays, respectively), while the dichlomethane fraction demonstrated significantly high antioxidant activity (IC50 = 43.6 ± 0.71 μg/mL in FRAP assay). In addition, a moderate antibacterial effect was observed against Pseudomonas aeruginosa, Klebsiella pneumoniae, and Staphylococcus aureus, as well as a remarkable efficiency against Candida albicans. According to the findings, the roots of the two plants contain a variety of phytochemicals with significant antibacterial and antioxidant properties, which support their use in traditional medicine.