Journal of Microbiology Research 2012, 2(4): 108-113 DOI: 10.5923/j.microbiology.20120204.08 Effects of Ocimum Gratissimum Leaves on Common Dermatophytes and Causative Agent of Pityriasis Versicolor in Rivers State, Nigeria Mbakwem - Aniebo C, Onianwa O, Okonko IO * Department of Microbiology, University of Port Harcourt, East-West Road, P.M.B. 5323, Choba, Port Harcourt, Rivers State, Nigeria mac2finney@yahoo.com, iheanyi.okonko@uniport.edu.ng Abstract This antifungal study on Ocimum gratissimum is rare in Nigeria and hence this study seeks to justify the ethobotanical uses of the plant. The antifungal activity of Ocimum gratissimum used by traditional medicine practitioners against the three major Dermatophytes – Trichophyton, Microsporum, Epidermophyton together with Malassezia furfur (the cause of Pityriasis versicolor (Eczema)), were studied by well-in-agar diffusion technique using different concentrations of ethanolic extracts. Isolates from the scalp, skin, toes and feet of forty individuals (mainly children) were obtained in four locations namely Aluu, Choba, Rumuosi and Emohua areas of Rivers State, Nigeria. The results of the study revealed the significant inhibitory effect of Ocimum gratissimum at five different concentrations of 250mg/ml, 200mg/ml, 150mg/ml, 100mg/ml and 50mg/ml used. The diameter zones of inhibition exhibited by the extracts against the test fungal species ranged between 12.50 and 20mm. The minimum inhibitory concentrations (MICs) of the ethanol extract of O. gratissimum was 50.01, 52.40, 63.06 and 63.09 mg/ml for Malassezia furfur, Microsporum, Trichophyton and Epidermophyton, respectively. Assessment of the various MICs showed that Ocimum gratissimum has great potential for use as an antidermatophytic agent. The study showed that the extracts from the leaves of Ocimum gratissimum had pronounced antifungal activities on all the fungi tested. The study has shown that the leaves extracts of O. gratissimum are quite promising and have strongly indicated the antifungal activity spectra of leaves extract of the plant. In conclusion, the results from this study indicated potentials of leaves extract of Ocimum gratissimum as a source of antifungal compounds. Keywords Antifungal activity, Antidermatophytic Agent, Ethanol Extract, Mics, Ocimum Gratissimum, Malassezia furfur, Microsporum, Trichophyton and Epidermophyton 1. Introduction Traditional medicine is a popular form therapy in devel- oping countries and its use is widely documented in various literatures[1-2]. Due to the huge potential of plant herbs in the discovery of novel therapeutic molecules, various na- tional governments have placed traditional medicine under the supervision of health ministries[3]. In many rural areas of Nigeria the use of herbal plants as treatments for various bacterial infections still thrives. Some of these plants have been analysed and shown to be effective against well known pathogens such as Staphylococcus aureus and Salmonella typhimurium[4-5]. Ocimum gratissimum L. is a shrub belonging to the family Lamiaceae. It is commonly known as Scent leaf or Clove basil and is found in many tropical countries. Africa and Asia * Corresponding author: mac2finney@yahoo.com (Okonko IO) Published online at http://journal.sapub.org/microbiology Copyright © 2012 Scientific & Academic Publishing. All Rights Reserved are however, the two continents where most variants of the plant exists[3,6-7]. O. gratissimum is found in the tropical and warm temperature regions such as India and Nigeria[8-9]. Some of the vernacular names in Nigeria include: (Ncho-anwu, Ahuji) Igbo, (Efinrin,) Yoruba, (Aramogbo) Edo and (Daidoya) Hausa[9-11]. O. gratissimum has been described to have other species in the flora of tropical West Africa. These include: Ocimum viride Linn, Ocimum suave Linn, Ocimum basilicum Linn and Ocimum canum Sims[9,11]. Mshana et al .[12] reported their numerous medical uses. The Ocimum oil has been described to be active against several species of bacteria and fungi. These include Listeria monocytogenes, Shigella, Salmonella and Proteus, for fungi Trichophyton rubrum, Trichophyton mentagrophytes, Cryptococcus neoformans, Penicillum islandi cum, and Candida albicans[4,9,13-16]. From recent findings, O. gratissimum has proved to be useful in the medication for people living with Human Immunodeficiency Virus (HIV), and Acquired Immuno Deficiency Syndrome virus AIDs[9,17]. In Congo, O. gratissimum decoction is used for