Antibacterial and antioxidant activities of crude aerial part extracts of Satureja Punctata (Benth) Briq

Abstract

This study evaluates the antimicrobial and antioxidant activities of the crude extract of an aerial part of Satureja punctata (Benth.) Briq. The dried aerial part of S. punctata (Benth.) Briq was extracted separately using aqueous, ethanol and n-hexane. The antibacterial activity against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa was assessed using disc diffusion method, and the minimum inhibitory concentration (MIC) and 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 aqueous and ethanol extracts exhibited significant antibacterial activities on the test microorganisms. The antibacterial activity of 600 mg/ml aqueous extract as measured by inhibition zones against S. aureus was 10.33±0.25 mm, E. coli 9.83±0.19 mm and P. aeruginosa 8.53±0.12 mm. The 600 mg/ml ethanol extract inhibited through zone of inhibitions S. aureus (10.33±0.41 mm), E. coli (9.37±0.18 mm) and P. aeruginosa (10.17±0.46 mm). Furthermore, the MIC values for both aqueous and ethanol extracts were from 75 to 100 mg/ml; whereas the MBC values for same extracts were from 100 to 150 mg/ml. 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 25 mg/ml concentration, respectively. The results showed that the aerial part of S. punctata contains components that have antibacterial and antioxidant properties that substantiate the medicinal importance of the plant.   Key words: Satureja punctata, antibacterial activity, antioxidant activity, zone of inhibition.