Chemical content and antimicrobial properties of three different extracts of Mentha pulegium leaves from Mugla Region, Turkey

Abstract

The extract of ethanol, methanol and DMSO of pennyroyal leaves from Mugla Region (Turkey) were tested for antimicrobial activity against eleven bacterial and one yeast strain by disc diffusion method. Among the extracts assayed, the methanol extract of pennyroyal leaves exhibited signifiant antimicrobial activity against Salmonella typhimurium and Staphylococcus aureus with 20 mm diameter inhibition zone. The DMSO extract of pennyroyal leaves displayed significant activity against S.aureus (19 mm) and Bacillus subtilis (21mm) showing inhibition zone of 19 mm and 21 mm diameter, while the ethanolic extract showed significant antimicrobial activity against S.aureus (17mm) and Klebsiella pneumoniae (20mm) inhibition zones. On comparint the MIC value of ethanol, methanol and DMSO leaf extract, methanolic extract of pennyroyal presented best activity (MIC 8 mg ml(-1)) against S.typhimurium CCM 583 and S.aureus ATCC 6538/P. Analyses of GC/MS determined eleven compounds viz., neophytadiene (69.95%), Pulejon 7.85%, Pinane 4.81%, Bicyclo (3.1.1 Heptane 2.6.6.6 trimethyl) 4.68%. In conclusion, methanolic extracts of M.pulegium showed antimicrobial activity because of high neophytadiene content.