Khosro Issazadeh - Department of Microbiology, Islamic Azad University, Lahijan Branch, Lahijan, Iran
Mohammad Reza Majid Khoshkholgh Pahlaviani - Department of Biotechnology, Lahijan branch, Islamic Azad University of Iran
Alireza Massiha - Department of Biotechnology, Lahijan branch, Islamic Azad University of Iran
Sirus Bidarigh - Department of Agriculture, Lahijan branch, Islamic Azad University of Iran
Masoud Giahi - Department of Chemistry, Lahijan Branch, Islamic Azad University of Iran
Panah Zulfagar Muradov - Azerbaijan National Academy of Sciences, Microbiology Department, Baku, Azerbaijan

Medicinal plants are a source of great economic value all over the world. Nature has bestowed on us a very rich botanical wealth and large number of diverse types of plants grows in different parts of the country. In this study the in vitro antimicrobial activity of crude ethanolic, methanolic and water extracts of the stem bark of O.basilicum were investigated. The extracts exhibited antimicrobial activities with zones of inhibition ranging from ۵ to ۱۲, ۸ to ۲۰ and ۰ to ۸ mm for ethanol, methanol and water extracts, respectively. The minimum inhibitory concentration (MIC) of the ethanol extract was between ۰.۵ and ۶.۲۵ mg/ml while that of methanol extract ranged from ۰.۵ to ۱۰ mg/ml. The minimum bactericidal concentration (MBC) for ethanol extract ranged between ۲.۰ and ۱۲.۵۰ mg/ml, while this value for methanol ranged from ۲.۰ to ۲۰ mg/ml. All the extracts exhibited appreciable activity against Candida albicans. The zones of inhibition exhibited by the extracts against C. albicans ranged between ۱۵ and ۱۸, ۱۵ and ۲۰ and ۵ and ۱۰ mm for ethanol, methanol and water extracts, respectively. Primary phytochemical screening revealed the presence of saponin, steroids, tannins, glycosides, alkaloids and flavonoids in the extracts. The ability of the crude stem extracts of O. basilicum to inhibit the growth of bacteria and fungi is an indication of its broad spectrum antimicrobial potential which may be employed in the management of microbial infections.It is also concluded that O. basilicum stem bark could be a potential source of active antimicrobial agents, and future works will be concentrated on the in vivo potencies and toxicological profiles.

O.basilicum, Antimicrobial Activity, Phytochemical screening