Assessment of Antibacterial Potentials of Lawsonia inermis L. (Henna) Leaf Aqueous Extracts

Antibiotic resistance has become a euphemism in the public health sector globally. The urge for alternative therapies led researchers to endorse the use of medicinal plants due to their cost-effectiveness and absence of side effects. This research was conducted to evaluate the antibacterial potential of henna leaf aqueous extract against clinical bacterial isolates. Different leaf aqueous concentrations of Henna (50, 25, 12.5, and 6.25 mg/ml) were tested against Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, and Staphylococcus aureus. The disc diffusion method was used to determine the antibacterial susceptibility of the isolates against the extracts. The phytochemical constituents of the extract were determined using standard procedures. The result revealed a significant difference (P≤0.05) in the effect of various concentrations of henna extracts on bacterial activities. The result showed that 50 mg/ml concentrations of henna leaf aqueous extract showed the highest activity on all the isolates. The activity of the 50 mg/ml extract is above 50% of that of the positive control. The MIC of the extract against the tested microorganisms ranged from 2.5-10.0 mg/ml, while the MBC obtained in the present study ranged between 20.0-40.0 mg/ml. The effect of the extract is concentration-dependent; it increases with an increase in concentration. The activity of the henna leaf aqueous extracts could be attributed to the presence of 7 active phytochemicals: Saponins, Steroids, Triterpenes, Flavonoids, Alkaloids, Glycosides, and Tannins. Thus 50mg/ml of henna aqueous extract is recommended against bacterial isolates.