In-vitro antibacterial activity of Pterolobium stellatum leaves extract against selected standard bacteria

Traditional use of herbal medicines implies substantial historical use, and this is certainly true for many products that are available as ‘traditional herbal medicines. The experimental study was conducted between February and May, 2016 at University of Gondar on antibacterial effect of leaf extract of Pterolobium stellatum. The purpose of the present study was to test the antimicrobial effect of P. stellatum extracted leaves against some standard pathogenic bacteria. The collected plant leave sample was extracted with the solvent ethanol, methanol, chloroform and distilled water. Finally, the antibacterial effect of the extract was tested with some bacteria species (Escherichia coli, Pseudomonas species, Salmonella species, Shigella species, Staphylococcus aureus and Streptococcus pyogenes) then the inhibition zone; the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined. The extract of ethanol and methanol solvents showed high antibacterial activity on both Gram negative and Gram positive bacteria. The higher and statistically significant (P<0.05) inhibition was seen in ethanol extract for all bacteria and the highest inhibition was shown against Shigella spp. (21.33±1.52) whilst the lower inhibition was statistically significant (P<0.05) with chloroform extract. Both the MIC and MBC of the test extract were effective at the lowest concentration.