In vitro antibacterial activity of two medicinal plants used in Bénin to treat microbial infections

Abstract

Dichloromethane, methanol and hydroethanol extracts of Casuarina equisetifolia L. and Oxalis corniculata L., two medicinal plants used by traditional doctors to treat microbial infections, were screened for their antibacterial activity against seven Gram positive and Gram negative bacteria (Escherichia coli, Staphylococus aureus, Enterococus faecalis, Pseudomona aeruginosa, Salmonella aboni, Staphylococus aureus meticilline resisting and Staphylococus epidermidis). The antibacterial activity was performed using the p-iodonitrotetrazolium microdilution method. The total activity and Artemia salina lethality of extracts were also determined. All extracts were effective against tested microorganisms at different levels with Minimum Inhibitory Concentration values ranging from 0.078 mg/ml to 5 mg/ml. The hydroethanolic extract was more potent than other extracts with a MIC value of 0.078mg/ml against S. epidermidis. The most interesting total activity was obtained with hydroethanolic extract of Oxalis corniculata (1689.7 ml). The methanol extract of Oxalis corniculata was also the less toxic to Artemia salina with LC50 value of 26.87 mg/ml.