Evaluation de l’activité antibactérienne et antifongique des extraits de Syzygium aromaticum L

Abstract

Clove (Syzygium aromaticum L) is one of the medicinal plants that has attracted considerable scientific interest. In this study, the antimicrobial activity of four different clove extracts was evaluated: methanolic, aqueous, dichloromethane, and ethyl acetate. The total phenolic and flavonoid contents of the extracts were determined by the Folin-Ciocalteu and aluminum chloride methods, respectively. The results showed that the aqueous extract contained the highest percentage of phenolic compounds, reaching 418 ± 2 μg gallic acid equivalents/mg of extract, while the methanolic extract was the richest in flavonoids, reaching 12.29 ± 1.45 μg quercetin equivalents/mg of extract. The effect of the four extracts on eleven different bacterial strains and seven fungal species was also studied using the agar diffusion technique. In general, significant inhibition of the growth of most bacterial and fungal strains was observed. The results showed that the diameters of the inhibition zones ranged between 10 and 22 mm, indicating the effectiveness of the clove extracts. Regarding antifungal activity, the ethyl acetate extract was the most effective. Regarding antibacterial activity, Staphylococcus aureus showed the greatest sensitivity to the methanolic extract, while Salmonella sp was the least affected by the same extract. Other extracts, such as the aqueous extract and the dichloromethane extract, showed variable effects. The minimum inhibitory concentration (MIC) was also determined, with a minimum of 0.025 mg/ml against Escherichia coli and a maximum of 12.5 mg/ml against Streptococcus aureus. In conclusion, clove extracts possess significant antibacterial and antifungal activity due to their high content of phenolic compounds.