SCREENING OF CRUDE ETHANOLIC EXTRACTS OF NINE LIBYAN MEDICINAL PLANTS FOR ANTIBACTERIAL ACTIVITY AGAINSTStaphylococcus aureusANDEscherichia coli

Abstract

The purpose of this study was to determine the effects of different concentrations of crude ethanolic extracts on two pathogenic bacterial strains. The various concentration of 10%, 5%, and 1% of crude ethanolic extracts of 9 plants belonging to diverse families was estimated for antibacterial activity against Staphylococcus aureus and Escherichia coli. The dried and ground plant materials were extracted in absolute ethanol 99.9% by cold-soaking for 48 h. The in vitro antibacterial activity was done by disc diffusion Assay (DDA). The zone of inhibition for the tested microbial strains was measured using the disc diffusion method. Imipenem (Ipm 10) was used as the positive control, while DMSO was the negative control. Among 9 medicinal plants used in this study, only (7) ethanolic extracts {H. stoechas L., M.parviflora (L.) Demonstr, S. arenariaForskal, P. rupestre L. M. longipetalaL., E. microcarpa and R. alba L.} Showed the range of inhibition zone between 7.66±0.57 to14.67±0.56 mm. However, the crude ethanolic extract of L.resedifolia (L.) O. Kuntze, and B. tournefortiiGouan presented no activity at all against pathogenic bacteria. Antibacterial susceptibility exposed that the most active antibiotics were ciprofloxacin, chloramphenicol, imipenem, and ticarcillin against S. aureus; ciprofloxacin, chloramphenicol, imipenem, and polymyxin against E. coli.