Evaluation de l’activité antibactérienne des extraits végétaux (cas de Portulaca oleracea L.)

Abstract

Abstract The objective of this study is the study of phenolic compounds and the evaluation of the antibacterial activity of the aerial part of Portulaca oleracea L. The crude methanolic, ethanolic and aqueous extracts were obtained by the maceration extraction methods, the respective yields are: 8.71%, 4.18%, and 31.39%; the ethanolic extract (EE) has the best value in the determination of polyphenols of 1.26 ± 0.007 mgEAG / g ES, even for the determination of condensed tannins (TCs) is the richest extract with a content of 0, 58 ± 0.007 mgEAC / g ES, while for the flavonoid assay the aqueous extract is the richest with a content of 0.3 ± 0.003mg EAQ / g ES. The antimicrobial activity was determined on six bacterial strains, according to thedisc diffusion method, the results show a variation in the sensitivity of the strains studied vis-à-vis the various extracts of the plant, a maximum inhibition on Klebsiela pneumoniae (11.5 mm inhibition zone) vis-à-vis -vis the aqueous extract and a minimum of inhibition on Bacillus subtilus and Staphylococcus aureus (zone of 6 mm inhibitions) vis-à-vis the ethanolic extract. Key words: Portulaca oleracea L., EA (aqueous extract), EE (ethanolic extract), EM (methanolic extract), total polyphenols, Flavonoid, antioxidant activity, antibacterial activity, Wadi Souf region.