ANTIMICROBIAL ACTIVITY OF MEDICINAL FLORA GROWING IN THE CENTRAL REGION OF SAUDI ARABIA

Background: This study was designed to the prospect of applying n-hexane extracts whole parts plants of Calligonum comosum L. , Zygophyllum coccineum L. , Heliotropium digynum L. , and Rhazya stricta L. to overcome the multi-drug resistant human pathogenic bacteria isolates; Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Klebsiella pneumoniae. Methodology: The medicinal plants were collected from Riyadh Region, Kingdom of Saudi Arabia and were extracted with n-hexane. Four Multi-drug resistant human pathogenic bacteria isolates i.e. E.coli, P. aeruginosa, S. aureus and K. pneumonia were selected for this study. The efficacy of n-hexane extracts was tested by using agar well diffusion assay and the zones of growth inhibition were measured in millimeter (mm). Results: The n-hexane extracts showed varied inhibition zones against tested multi- drug clinical isolate human pathogens. The results determined that, all the plant extracts showed antibacterial activity against four tested bacterial pathogens. The n-hexane extract of C. comosum showed stronger and broad spectrum activity against the tested isolates as related to the other extracts that indicate moderate action. Data showed the highest and lowest zone inhibition effects against multi drug resistant clinically Human Pathogens at concentration of 100mg/ml. Conclusions: It is concluded that the n-hexane extracts of C. comosum, Z. coccineum, H. digynum, and R. stricta have antimicrobial potential activity against common human bacterial pathogens.