In-vitro Antifungal Activities of Cola nitida Schott & Endl. (Sterculiaceae) against Five Candida species and Four Dermatophytes
B. A. Adeniyi *
Department of Pharmaceutical Microbiology, University of Ibadan, P.O.Box 22346, Ibadan, Nigeria.
O. O. Mebude
Department of Pharmaceutical Microbiology, University of Ibadan, P.O.Box 22346, Ibadan, Nigeria
T. O. Lawal
Department of Pharmaceutical Microbiology, University of Ibadan, P.O.Box 22346, Ibadan, Nigeria.
K. E. Nwanekwu
Department of Pharmaceutical Microbiology, University of Ibadan, P.O.Box 22346, Ibadan, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Aims: Various medicinal and pharmacological values have been observed in species of Cola including their use to treat mouth infections, whooping cough and ringworms. Some studies have been done on their antibacterial and anti-mycobacterial but little or none on antifungal potential. This study was designed to study the antifungal activities of crude extract of Cola nitida against five Candida species and four dermatophytes implicated in various oral and skin infections in vitro.
Place and Duration of Study: Department of Pharmaceutical Microbiology, University of Ibadan, Ibadan, Nigeria, during March 2007 to July 2011.
Methodology: Preliminary phytochemical screening was done using standard conventional methods. Antifungal activity was carried out using the agar cup diffusion technique at 2.0 mg/mL while the minimum inhibitory concentration (MIC) was carried out using the agar dilution method. The kill kinetics study was done using viable counting technique.
Results: The methanol extracts of Cola nitida leaf and Cola nitida seed exhibited significant inhibitory actions against all the 9 pathogens with the formal more effective than the later. Both the minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC) of the plant extract ranged from 0.0625 to 1.00 mg/mL. The antifungal activity of Cola nitida compares favorably well with the control ketoconazole. Phytochemical analyses reveal the presence of tannin, saponin and alkaloids, although at varying degrees. Kill kinetics reveals a concentration dependent decline in the microbial load of the tested organisms with time. The rate of decline increased with increase in concentration.
Conclusion: Current study supports the ethno-medicinal uses of the plants as potential antifungal agents.
Keywords: Cola nitida, MIC/MFC, antifungal, kill kinetics.