SYNERGISTIC ANTIBACTERIAL ACTIVITY OF SOLANUM INCANUM AND PREMNA SCHIMPERI LEAF EXTRACTS AGAINST STANDARD AND CLINICALLY ISOLATED PATHOGENIC BACTERIA

Abstract

Medicinal plants are used as essential methods for handling various diseases particularly in developing countries. Because they have a potential to cure different physical and Physiological complications by using the chemical substances produced within them and found in different parts: leaf, root, stem or all parts of the plant. Thus the aim of this study was to assess the antibacterial activity of solanum incanum and premna schimperi leafe extracts and their synergistic activity against selected pathogenic bacteria; such as: Escherichia coli, Staphylococcus aureus, Salmonella typhimurium, and Klebsiella pneumoniae, clinical isolates and standard strain. Ethanol, methanol and chloroform crude leaf extracts of S. incanum, P. schimperi and their synergistic were assessed against tested pathogenic bacteria using agar well diffusion method; the inhibitory zones were recorded in millimeters. Gentamycin was used as positive controls, while Dimethyl sulfoxide (DMSO) was served as negative control. The minimal inhibitory concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the plant extracts against test microorganisms were assessed using broth dilution and agar culture techniques respectively. The combined leaf extract produced the highest mean inhibition zone (22.67mm±0.577) compared to the use of S.incanum (22.33mm±2.082) or P.schimperi extracts (21.33mm ±3.055) independently. The results of this study also demonstrated that ethanoic extracts used against the majority test microorganisms showed antimicrobial and synergistic effect with most antibiotics better than methanol and chloroform extracts. The inhibition zone of the synergistic antibacterial effect of S. incanum and P. schimperi leaf extracts against most tested pathogenic bacteria was greater than the antibacterial activity S. incanum and P. schimperi used independently. Accordingly, the present finding supports the traditional use of those plants in combination and separate for treating pathogens by the community. And also there is a requirement for detailed scientific study of traditional knowledge to confirm that valuable therapeutic knowledge of some plants is preserved as well as to provide scientific evidence for their efficacies