The antibacterial, antioxidant and cytotoxicity effects of S. officinalis in an in vitro study

Natural plant products are the best candidate for antimicrobial and antioxidant properties and are the suitable alternative for chemical drugs. This study aimed to examine the antimicrobial effect of ethanol extract of S. officinalis on S. aureus, E. coli, K. pneumoniae and P. aeruginosa and its comparison with antibiotic discs of ciprofloxacin, ceftriaxone and gentamicin. In this experimental study the ethanolic extract of S. officinalis was extracted by maceration method and the concentrations of 1.9, 3.9, 7.8, 15.6, 31.2, 62.5, 125, 250, 500 and 1000 μg/ml were obtained. Standard microbial strains of S. aureus, E. coli, K. pneumoniae and P. aeruginosa were purchased from pasture Institute and the amount of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extracts was determined using micro dilution method. Antioxidant and cytotoxicity were evaluated using Diphenyl-1-Picrylhydrazyl (DPPH) Radical Scavenging Capacity and MTT assays. The ethanol extract of S. officinalis had different effects on S. aureus, E. coli and P. aeruginosa strains and inhibition zone diameter of 32.66, 10.83 & 10.6 mm were observed respectively. S. officinalis had an inhibitory effect on all of the studied bacteria except K. pneumoniae and this effect was higher in S. aureus bacteria. Also, the inhibition zone diameter of S. officinalis extracts was exceptionally higher in S. aureus compared to ceftriaxone and gentamicin. Moreover the ethanol extract of S. officinalis showed acceptable antioxidant and no cytotoxicity effects. Our results indicated that S. officinalis extracts had the greatest antibacterial effect on the gram-positive bacteria. Although the inhibition zone diameter of S. officinalis extracts was exceptionally higher in S. aureus compared to ceftriaxone and gentamicin.