Activité antimicrobienne des extraits phénoliques de Juniperus phoenicea et Glycyrrhiza glabra

Abstract

Our study focused mainly on the evaluation of the antimicrobial potential of two medicinal plants belonging to the Algerian Mediterranean flora, namely, Juniperus phoenicea and Glycyrrhiza glabra. Extraction by maceration of the phenolic compounds from the dried leaves and berries of Juniperus phoenicea and dried roots of Glycyrrhiza glabra gave respective yields of 56.15%, 47.40% with methanol/water at 70% and 52.45% 42.30% with ethanol/water at 70%. The quantitative analysis of the phenolic compounds shows that the hydromethanic extract of both plants is richer than the hydroethanolic extract with a content of 122.88 ±6.64 mg EAG/g dw and 120.54 ±3.35 mg EAG/g dw in total phenols, 15.48 ±4.97 mg EQ/g dw, 14.01 ±8.57 mg EQ/g dw in flavonoids and 42.34 ±10.15 mg EC/g dw, 40.14 ±14.78 mg EC/g dw in condensed tannins, with J. phoenicea and G. glabra respectively. The results of the antimicrobial activity evaluation showed that the hydromethanolic extract of J. phoenicea, G. glabra and their association were found to be active against S. aureus ATCC 33862, and inactive against P. aeruginosa ATCC 2785, E. coli ATCC 25922, C. albicans ATCC 10231. The results of the determination of MIC and MBC have given values of 10 mg/ml, 80 mg/ml respectively with the hydromethanolic extract of J. phoenicea and values of 20 mg / ml. 80 mg/ml respectively with the hydromethanic extract of G. glabra and values of 2.5 mg/ml, 20 mg/ml with the associated extract of the two medicinal plants.