Medicina alternativa e integrativa

Stability and Efficacy of Anti-dermatophyte Creams From Extract of Kigelia africana Leaves

Abstract

Fawehinmi AB and Oyedeji FO

Dermatophytosis are skin infections caused by dermatophytes which can be pathogenic for humans and animals by infecting the stratum corneum, nails, claws or hair and which now affect more than 20%-25% of the world populations especially in the developing countries. Drug resistance and toxicity associated with long-term treatment with existing antifungal drugs necessitate the search for new drugs to treat dermatophytosis. The juice of Kigelia africana leaves has been used by the natives to treat dermatophytosis. The leaves were extracted with water, ethanol and petroleum ether. Phytochemical analyses of the extracts were carried out. Agar disc discussion method was used to determine the antifungal activities against clinical isolates of Microsporum audouinii, Epidermophyton floccosum, Trichophyton mentagrophytes and Malassezia furfur. Herbal creams formulated with 0.5, 1.0 and 2.0 g w/w of the extract were subjected to stability tests using standard methods. FTIR was used to determine if there were new functional groups formed during production of the herbal creams. Sensitivity and efficacy of the products were determined using animal model experiment.

The percentage yields of extracts are petroleum ether 6.3%, aqueous 6.5%, and ethanol 7.2%. Percentage ethanol phytochemical composition indicated that for Alkaloid (4.67%), saponins (2.48%), flavonoids (0.81%) and tannins (1.05%). The emulsion produced was an oil-in-water emulsion and had a white colour with pH of 7.02 spread of emulsion, rubbing-in effect and stability to centrifugation was very high. The antifungal results showed that the petroleum ether and aqueous extracts had 10 mm zones of inhibition, while ethanol extract had 15 mm at 10,000 μg/ml against Trichophyton mentagrophytes. Against Microsporum audouinii, the results are petroleum ether and aqueous extracts (10 mm) and ethanol extract (14 mm). Against Epidermophyton floccosum, the results are petroleum ether and aqueous extracts (10 mm) while ethanol was 13 mm. The zones of inhibition recorded by the extracts against Malassezia furfur are aqueous 4 mm, petroleum ether 12 mm and ethanol 15 mm respectively. The results for FTIR showed a spectrum of C-N stretch which peaks at 1019.00 cm-1 for Ka cream. Also, an O-H stretch peak was observed at 3254.00 cm-1. Temperature stability tests carried out indicated increasing stability in the order Ka.water cream E. floccosum (30.53 μm) < M. audouinii (31.37 μm) <M. furfur (36.22 μm) <T. mentagrophyte (37.01 μm).

The results showed that Kigelia africana ethanol extract can be used in herbal cream formulations for the management of dermatophytosis.