Effet du solvant sur le contenu phénolique, la capacité antioxydante et l'activité antimicrobienne de l'Acacia arabica

Abstract

In this study, the active compounds (polyphenols) were extracted from the pods and seeds of Acacia arabica, a plant native to southern Algeria. The antimicrobial activity was also tested using methanolic extracts and vinegar (concentrated and diluted). The concentrations of polyphenols obtained by methanolic extraction were (507±0.22 and 1671.75±0.14) mg EAG/g MS for seeds and pods respectively, the concentrations obtained by diluted vinegar were about (503±0.11 and 1012±0.09) mg EAG/g MS, the concentrated vinegar extract gave concentrations of (369±0.03 and 934±0.09) mg EAG/g MS. The antioxidant activity showed significant values with the methanolic extract compared to the vinegar extracts. The antimicrobial activity tested for the three solvents used gave the hydromethanolic extract of the pods, in particular, excellent antimicrobial power against the pathogenic strains tested, as evidenced by inhibition zones between 10.20±0.42 and 21.91±0.98 mm reported for Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Staphylococcus aureus, Bacillus cereus and Salmonella typhimurium strains. In the same experimental protocol, inhibition zones ranging from 9.97±0.29 to 17.04±0.57 mm were recorded for diluted vinegar extract and inhibition zones ranging from 9.44±0.82 to 20.92±0.64 mm were recorded for concentrated vinegar extract. It is concluded that polyphenols from Acacia arabica pods could serve as excellent antimicrobial agents against the studied pathogenic bacteria. Key-words:Acacia arabica - polyphenols - extract - antimicrobial activity - antioxidant activity - pathogenic strains.