Potentiating Antifungal Activity of Fluconazole or Nystatin with Methanol Bark Extract of Harungana madagascariensis Stem Bark

The therapeutic failures and the increasingly high costs of treating resistant bacterial infections calls for alternative means of care. The present study was initiated to evaluate the antifungal properties of the Harungana madagascariensis methanol barks extract and potent interactions with some usual drugs. The extract was prepared by maceration of the dry stem bark powder in methanol. Phytochemical analysis was carried out by colorimetric assays. Antifungal activity as well as interactions between extract, Nystatin or Fluconazole was evaluated by broth microdilution method. The therapeutic efficacies of H. madagascariensis extract and Fluconazole – extract mixture as compared to Fluconazole extract was studied in experimental models of oral and vulvovaginal candidiasis in rats by oral route. Results showed that methanol extract of H. madagascariensis stem barks had antifungal activity ranging from 128 to 1024 µg/ml. This extract also had a fungicidal activity on all of the tested yeasts. Moreover, the extract presented in vitro synergetic and additive interactions with Nystatin and Fluconazole. In both oral and vaginal infection model, all the treatment significantly reduced (P less than 0.05) the number of colony formant unit (UFC) of C. albicans compared with untreated control. Moreover, significant decrease in the percentage of animals showing positive cultures was observed in rats treated with Fluconazole-extract mixture. In both therapeutic efficacy studies, the histological findings confirmed the microbiological results. The results of this study constitute a base for the usage of H. madagascariensis stem barks in association with Fluconazole to overcome yeast infection.