The Antibiotic Potential of Moringa oleifera Leaf on Staphylococcus aureus
Giami, Lynda Kadi *
Department of Medical Microbiology, Faculty of Medical Laboratory Science, Rivers State University, Nigeria.
Sampson, Tonye
Department of Microbiology, Faculty of Science, Rivers State University, Nigeria.
Monsi, Tombari Pius
Department of Medical Microbiology, Faculty of Medical Laboratory Science, Rivers State University, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Moringa oleifera, often referred to as the "drumstick tree" or "miracle tree," has been celebrated in traditional medicinal systems for centuries because of its nutritional and therapeutic properties. Antibiotic resistance to conventional antibiotics has continued to be a therapeutic challenge in clinical settings. To this end, alternative therapeutic approaches are being sought. One such approach is the use of antimicrobial inhibitors from natural sources like medicinal plants. This study aimed to explore the antibacterial potential of aqueous and ethanolic leaf extracts of Moringa oleifera plant against Staphylococcus aureus isolated from roasted meat ‘Suya’ in Port Harcourt, Nigeria. The antibacterial activity of Moringa oleifera leaf extracts against S. aureus was determined in vitro in aqueous and ethanolic extracts using the cup plate method at four different extract concentrations (400 mg/ml, 200 mg/ml, 100 mg/ml and 50 mg/ml). Aqueous and ethanolic extracts were tested for antibacterial activity using agar diffusion, MIC, and MBC assays. The ethanolic extract showed zones of inhibition of 25mm at a concentration of 400 mg/ml, 21mm at 200mg/ml, 13mm at 100mg/ml and 8mm at 50mg/ml. Minimum Inhibitory Concentration (MIC) and the Minimum Bactericidal Concentration (MBC) were at 200 mg/ml for the ethanolic plant extract, while no MIC and MBC were observed for the aqueous plant extract. Antibiotic susceptibility testing using the Kirby-Bauer disc diffusion method revealed that Staphylococcus aureus was susceptible to Ciprofloxacin, Amikacin and Norfloxacin but resistant to Nalidixic acid. The results from this study have further confirmed the promising antibacterial potential of M. oleifera in inhibiting the activities of S. aureus. Moreover, the results of this study revealed the presence of the phytoconstituents tannins, flavonoids, alkaloids, saponins and terpenes in the extract of Moringa oleifera plant leaves, with the ethanolic plant extract exhibiting a more inhibitory effect on S. aureus than the aqueous plant extract.
Keywords: Staphylococcus aureus, roasted meat (‘Suya’), antibacterial activity, phytoconstituents, Moringa oleifera