Journal of Pure and Applied MicrobiologyVol. 11 No. 3

Investigation of Antimicrobial Activity of 13 Thai Medicinal Plants against Bacteria and Fungi

Nisarat Siriwatanametanon1*, Wanwisa Dodgson2 and Jolyon L.A. Dodgson2

1Department of Pharmaceutical Botany, Faculty of Pharmacy, Mahidol University, Bangkok, Thailand. 2Microbiology and Applied Microbiology Research Unit, Faculty of Science, Mahasarakham University, Mahasarakham, Thailand.

Received on 10 June 2017 and accepted on 20 July 2017



Thirteen medicinal plants used in Thai traditional medicine for the treatment of inflammatory diseases were screened for in vitro antibacterial and antifungal activities. The agar disc diffusion method was employed against five strains of bacteria (Bacillus cereus, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi) and four strains of fungi (Candida albicans, Candida tropicalis, Candida glabrata and Candida guilliermondii). The 13 plants were extracted with methanol and the antimicrobial results were evaluated as the diameter of the inhibition zone of microbial growth. The results showed that the extract with the greatest activity against the gram-positive bacteria was Garcinia mangostana (peri-carb). The extract with the greatest activity against the gram-negative bacteria was Psidium guajava (leaves). The extracts with the greatest activity against Candida was Psidium guajava (leaves) and Allium sativum (bulbs). The results support the ethnopharmacological uses of the tested plants, especially G. mangostana, P. guajava and A. sativum.

Keywords : Antibacterial, Antifungal, Garcinia mangostana, Psidium guajava, Allium sativum.