Antibacterial Activity of Metanolic Extract of 12 Herbal Species on 6 Bacterial Strains Using Cylinder-plate Method

Resistance to antibacterial agents and sensivity reaction to such chemical compounds are the main reasons for investigators to develop new antibiotics from herbal sources. Antimicrobial effects of Metanolic extract of 12 herbal species Pistacia atlantica, Amygdalus scoparia, Cuscuta epthymum, Ephedra procera, Salsola boryosm, Sameraria armena, Scabiosa olivier, Scorzonera tortuosissima, Lepyrodielis holosteoidea, Vaccaria pyramidata, Sonchus oleraceam and Silene conoidema on 6 bacterial strains Staphylococcus aureas, Staphylococcus epidermidis, Echerichia coli, Kelebsiella pneumonia, Pseudomonas aeroginos and Bacillus subtilis were, separately, studied using Cylinder-plate method.

In this laboratory study, methanolic extracts of herbal strains were prepared by maceration and after concentrating the extracts were dried. Then the concentrations of 50, 25, 12.5, 6.25 and 3.125 mg/ml of the extracts were prepared using 1:1 solution of DMSO/methanol. The standard bacteria with certain concentration (0.5 MacFarland) were inoculated on to the Muller-Hinton agar medium. Prepared extracts were dropped into cylinders and 18-24 hours after incubation and penetration of extract into the culture medium, the antibacterial effects and growth inhibitory zone (mm) were measure and values were expressed as (Mean ± SEM).

The least and the most amount of effective concentration were 3.125 mg/ml and 50 mg/ml, respectively. The most inhibitory diameter belonged to methanolic extract of Amygdalus scoparia on Staphylococcus epidermidis which was equal to19 ± 0.3mm.

Metanolic extracts of herbal species of Pistacia atlantica, Amygdalus scoparia and Ephedra procera had the most antibacterial effects compared to gentamicin as positive control. Regarding the side effects of the synthetic drugs and also benefits of such herbal extracts, extracts of these herbs as antibacterial agents after further investigations seems to be useful.