Evaluation of antibacterial activity of Avicennia marinayoung branch and mature leaf extract in Khoor-e-Tiab, Hormozgan province

Introduction and Many pathogens responsible for human disease have become resistant to antibiotics and therefore finding new antibacterial agents are essential. Regarding to the fact that mangrove plant (Avicennia marina) has been used in traditional herbal medicine in south of Iran, this study has been designed to identify the antibacterial effect of extract of mature leaf and young branch of the mangrove plant. The extracts of dried leaf and branch were prepared using Soxhlet extraction method and ethyl acetate and methanol were used as solvents. Then the antibacterial effects of this plant were screened by using well agar diffusion technique against few gram positive and negative bacteria, in three different volumes of 10, 20, and 30 microliter, with concentration of 100mg/ml and the diameter of inhibitory zone was measured. Also MIC and MBC of extract of leaf and branch of mangrove plant were measured. The highest inhibitory zone (28mm) with ethyl acetate extract of both branch and leaf of mangrove plant in volume of 30 µl, was in Shigella dysenteriae. Lowest MIC (0.4mg/ml), MBC (0.5mg/ml) with extracts of branch using ethyl acetate as solvent was shown for Bacillus subtilis. Results of this research has shown that extract from branch of mangrove plant using ethyl acetate as solvent has beneficial antibacterial effect against gram positive bacteria and it appears that plant structure of the branch has bigger active biological antimicrobial effect in compare to leaf.