Inhibitory Effect of Crude Aqueous Brucea amarissima Extract on the Growth Profile of Oral Candida
The prevalence of oral Candida infections has increased, due to immunosuppressive effect of antifungal agents on resistant hosts [1,2]. Growth rate is a key attribute of virulence among infectious microorganisms including Candida species. The aim of this study was to evaluate the growth inhibitory effect of Brucea amarissima (Lour.) Merr. leaves extract based on changes in the pattern of growth profile of Candida sp. Candida albicans, Candida tropicalis and Candida dubliniensiswere used in this study. Crude extract of B. amarissima was prepared and the minimal inhibitory concentrations (MICs) towards Candida sp. were determined. The growth responses were recorded based on changes in the doubling time (g-values) and specific growth rates (µ-values). The values in the presence of extract were computed as percentage in the optical density (OD) relative to the total cells suspension in the absence of extract. 0.12% w/v chlorhexidine (CHX)-containing mouth rinse and sterile distilled water were used as controls. C. tropicalis was found to have the highest growth rates indicating high bioactivities and reproducibilities. C. dubliniensis and C. tropicalis showed the highest reduction of µ-values at a minimal concentration with 87.04% and 57.28%, respectively. At higher concentration (6mg/mL), the extract exhibited significant reduction towards the growth (ρ<0.05). Also, was able to reduce the µ-values of all Candida strains with more than 90% reduction. The extract exhibited fungistatic (<6mg/mL) and fungicidal (>6mg/mL) activities towards oral Candida sp. hence, may be considered as a promising candidate for the development of antifungal agent of natural products.
Acknowledgement: University of Malaya Research Grant (UMRG) (RG095/09HTM), Postgraduate Research Fund (PS160/2010B).
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2. Bastert J, Schaller M, Korting HC, and Evans EG (2001) Int J Antimicrob Agents 17:81–91.