Phytochemical Screening and Anti-microbial Activity of Polygala sadebeckiana Gurke extracts on bacterial isolate from wound samples of patients with “Shimetere”

Abstract

Background As Guraghe community believed that modern medication use especially through injection route seriously aggravate the disease, the root part of Polygala sadebeckiana Gürke is commonly used as traditional medicine in the management of “Shimetere”, which is a common skin and soft tissue infection in the community. The aim of this study was to evaluate anti-microbial activity of Polygala sadebeckiana Gürke extract on bacterial isolate from wound samples of patients with “Shimetere”. Methods Agar well diffusion method was used to evaluate antibacterial activity and agar dilution method was utilized to determine minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MIC). The crude extract was tested against isolated bacteria at the concentration of 25, 50, 75 and 100 mg/mL in triplet (3x). The positive controls were azithromycin (15µg) cloxacillin disk (5µg) and the negative control was dimethylsulfoxide (5%). The group means comparisons were made using one-way ANOVA at a significance level of p < 0.05 and the results were presented as mean ± standard deviation. The presence of secondary metabolites from crude extract was checked by standard testing procedures. Results S. aurous and S. pyrogen were the two identified bacteria from 9 (60%) and 3(20%) of wound samples, respectively. All identified bacterial strains were susceptible for the reference antibiotics. Tannins and saponins were the most abundant secondary metabolites found in the crude extracts. The average inhibition zone of the plant extract with 100, 75, 50 and 25 mg/mL concentration were 27, 20.33, 15.25, 11.96 mm (p < 0.000) for S.aurous and 30.02, 24.50, 19.07, 15.77 mm (p < 0.000) S.pyrogen bacteria. MIC and MBC of the crude extract were 1.67 and 10 mg/ml for S. aureus and 0.98 and 4 mg/ml for S.pyrogen. Conclusion Polygala sadebeckiana Gürke contained significant tannins and saponin as a secondary metabolites and had antibacterial activities against isolated bacteria (S. aurous and S. pyrogen ) from “Shimetere”.