Potencial antidermatofítico de Mo-CBP4, uma proteína ligante à quitina de sementes de Moringa oleifera

Abstract

Dermatophytosis constitute an important public health problem, affecting about 25% of world population. Several drugs are available for the dermatophytosis treatment, but they cause many adverse effects, including severe toxicity, drug interactions, low efficacy and resistance. Thus, there is a need for the development of new drugs with improved efficacy and safety. Medicinal plants are a valuable source of natural products that can act as drugs, being an alternative to conventional treatments. Moringa oleifera Lamarck, a plant native from Northeast of India, is widely used for its nutritional, therapeutic and water purification properties. Thus, this study aimed to evaluate the antidermatophytic potential of Mo-CBP4, a chitin-binding protein purified from M. oleifera seeds. By in vitro assays, Mo-CBP4 showed inhibitory activity against the fungus Trichophyton mentagrophytes, with a MIC50 of 500 µg/mL. In contrast, Mo-CBP4 did not inhibit the fungus T. rubrum, even at a higher concentration (1000 µg/mL). Mo-CBP4 (500 μg/mL) was able to inhibit the conidia germination of T. mentagrophytes, but not the mycelial growth. In relation to the mode of action, the antifungal activity of Mo-CBP4 does not seem to involve the carbohydrate interaction site since the protein remained active even when incubated with 0.15 M N-acetyl-D-glucosamine. The antifungal activity of Mo-CBP4 appears to result from the increased permeability of the conidia cell membrane and induction of oxidative stress within the cell, cause by this protein. Mo-CBP4 also showed antifungal activity against T. mentagrophytes by in vivo assays. In dermatophytosis model using albino Swiss female mice the hydrogel containing Mo-CBP4 (5 and 10 mg/g) was effective, reducing the lesion severity and shortening the infection period. The findings indicate that Mo-CBP4 has potential for development of a novel antifungal drug for clinical treatment of dermatophytosis caused by the fungus T. mentagrophytes.