Determination of Antimicrobial Activity and Phytochemical Screening of Selected Medicinal Plants in Tigray region of Northern Ethiopia

Present paper evaluates the antimicrobial activities and preliminary phytochemical screening of the extracts of Beciumgrandiflorum, Meriandrabengalensis, Tamarindusindica, Balanitesaegyptiaca and Otostegiaintegrifolia . Comparative study was made for the selected traditional medicinal plants. The results of phytochemical test indicate that the bioactive chemical components show presence of alkaloids, flavonoids, phenols, carbohydrates, saponins and terpenoids. The antimicrobial activities of aqueous and ethanol extracts of leaf and stem were determined on the selected bacteria strains. The results indicate that the aqueous and ethanol leaf extracts of Meriandrabengalensis show better antimicrobial activity against Staphylococcus aureus and Staphylococcus pneumonia with inhibition zone diameters of 15.97 ± 0.09 and 19.03 ± 0.15 mm respectively, significant at (P<0.05) compared to other extracts. From the phytochemical components tested, carbohydrate was present in Becium grandiflorum extract. The lowest inhibition zone (4.5 ± 0.29 mm) was achieved for the extract of Balanitesaegyptiaca. The phytochemical component saponinis significantly present in Meriandrabengalensis in the aqueous leaf extract. In the comparative study made for the extraction solvents aqueous and ethanol, the aqueous extraction had strong inhibition zone. Therefore, a study need to be done on the isolation, identification, and quantitative determination of antimicrobial components present in the Meriandrabengalensis for its application in both animal and human pharmaceutical industries. Keywords : Antimicrobial activities; Phytochemical screening; Extracts; Inhibition zone; Medicinal plants; Tigray; Ethiopia.