ISSN 2169-303X
International Journal of Medicinal Plants Research ISSN 2169-303X Vol. 8 (9), pp. 001-004, September, 2019. © International Scholars Journals
Full Length Research Paper
The essentials oils and antimicrobial activity of four nepeta species from Morocco
Laila Zenasni1, Houssine Bouidida2, Amina Hancali3, Amina Boudhane3, Hassan Amzal1 Abdelkader Il Idrissi2, Rajae El Aouad3, Youssef Bakri1 and Abdelaziz Benjouad1*
1Laboratoire de Biochimie et Immunologie, Faculté des Sciences, Rabat, Morocco.
2Laboratoire de chimie des plantes et de synthèse organique et Bio-organique, Faculté des Sciences, Rabat, Morocco.
3Laboratoire de Microbiologie, Institut National d’Hygiène, Rabat, Morocco.
Accepted 08 April, 2019
Abstract
The chemical composition of essential oils (EO) isolated from four Nepeta species (Nepeta atlantica Ball, Nepeta tuberosa L. subsp reticulata (Desf.) Maire, Nepeta cataria L., Nepeta granatensis Boiss) were characterized and the antibacterial activity tested. Chemical analyses indicated that the major component of these EO was the sterioisomere 4a-a, 7-a, 7a-b-nepetalactone which represented more than 70% of oils from N. atlantica, N. tuberosa, N. cataria and 39.4% of oils from N. granatensis. The EO from N. atlantica, N. tuberosa, and N. cataria presented comparable antibacterial activity against tested bacteria. Statistical analysis indicated that S. aureus (ATCC 25923) and E. coli (ATCC 25922) strains were the most sensitive to the EO (MICs ranged from 4.37 to 16.25 µL/mL), these strains were more sensitive than clinically isolated E. coli, S. aureus and S. enteritidis and P. aeruginosa (ATCC 27853) strains. The EO from N. granatensis contained low nepetalactone concentrations and showed relatively poor antibacterial activity against tested bacteria (MICs ranged from 22.50 to 80.00 µL/mL). These results indicate that the antibacterial activity of EO from the Nepeta genus depends on their chemical composition and suggests that nepetalactone plays an important role in antibacterial activity against E. coli and S. aureus strains, two microorganisms which cause morbidity and mortality worldwide.
Key words: Nepeta atlantica, Nepeta tuberosa, Nepeta granatensis, Nepeta cataria , Lamiaceae, essential oil composition, 4a-a, 7-a,7a-b-nepetalactone, antibacterial activity.