Mekonnen Yalemtsehay (Professor)Melaku Mesfin2019-11-212023-11-082019-11-212023-11-082015-08-05http://etd.aau.edu.et/handle/123456789/20185The ever-increasing demand for antimicrobial products against resistant infectious (microbial) agents necessitates their search from microorganisms and medicinal plants. The Satureja punctata (locally known as “lomishet”, Amharic) is one of such plants used as herbal medicine in different parts of Ethiopia. The objective of this study is to evaluate the antimicrobial and antioxidant activities of the crude aerial part extract of the plant against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa and its toxicity on animal mouse model. The aerial parts were collected from Entoto and Sendafa and extracted using absolute ethanol, water and n-hexane. The Antibacterial activity was assessed using disc diffusion method, and the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the extracts were determined by the agar dilution method. The radical scavenging activity of the extracts was evaluated by DPPH assay. The result indicated that the solvent extracts exhibited antibacterial activities on the test organisms, except the n-hexane and the activities were dependent on solvent type and concentration. Consequently, the maximum antibacterial activity was displayed by the aqueous extract against S. aureus(10.33±0.25mm), E. coli (9.83±0.19mm) and P.aeruginosa (8.53±0.12mm) and by ethanol extract against S. aureus (10.33±0.41mm), E. coli(9.37±0.18mm) and P.aeruginosa (10.17±0.46mm) at the concentration of 600mg/ml. Furthermore, the MIC values for both ethanol and water extracts were from 75 to 100 mg/ml; whereas the MBC values for ethanol and water extracts were from 100 to 150mg/ml and100mg/ml, respectively indicating that the ethanol-extract was slightly more effective than the water extracts. The in vitro free radical scavenging activity showed that the aqueous, ethanol and n-hexane extracts showed maximum antioxidant activity of 87.89%, 78.68% and 47.18% at 25mg/ml concentration, respectively. Thus, the plant showed interesting antioxidant activity that could be useful in the management of oxidative stress. Oral administration of crude ethanol extract at the dose of 2000 mg/kg did not show any mortalities or evidence of adverse effects on the Swiss albino mice, implying that S. punctata is non-toxic to the animal model.enAlbino MiceDisc DiffusionMbc and MicThesis