Preparação e avaliação da atividade antimicrobiana de formulações para uso tópico com extrato etanólico das cascas de banana (Musa paradisiaca)

Abstract

The use of medicinal plants in the treatment of diseases is a widely used practice in the world. Several extracts of medicinal plants have antimicrobial effects, especially when associated with antibiotics of clinical use, representing therapeutic alternative for infectious diseases. Musa paradisiaca, popularly known as Banana, is a species belonging to the family Musacea, its use is diversified, and has been reported as healing, antidiarrheal, antipyretic, analgesic, hypoglycemic, antiallergic, in the treatment of gastric and venous ulcers, thrush, ocular diseases and leishmaniasis. Due to this widespread use in folk medicine and in the search for natural products based pharmaceutical products, this work aimed to evaluate the antimicrobial activity of ethanolic extracts from banana peels (Musa paradisíaca) from harvest and disposal, and to develop formulations containing these extracts at the concentration of 5% and 10%. From the extractive process by maceration and turbolysis four ethanolic extracts were prepared, which were subjected to phytochemical screening through thin layer chromatography (CCD). All extracts analyzed showed the presence of flavonoids (rutin) and terpenes (betasitosterol); the routine being evidenced and quantified by high performance liquid chromatography coupled to the photodiode array detector. As recommended by the National Formulation of the Brazilian Pharmacopoeia, the bases of nonionic cream and natrosol gel were prepared and the extracts were incorporated in the concentration of 5% and 10%. The products were evaluated against strains of gram-positive and gram-negative bacteria, yeasts and filamentous fungi. The microdilution technique was used to determine the minimum inhibitory concentration (MIC). The extracts of the banana peel (M. paradisíaca) obtained by maceration (E1) showed good antimicrobial activity against S. aureus, S. epidermidis and B.subtillis strains with MIC of 512 μg / mL as well as strains of C. albicans, C. tropicalis and C. Krusei with MIC of 256 μg / mL, while extracts of the banana peel (M. paradisíaca) of the harvest obtained by turbolysis (E4) presented MICs of 512 μg / mL strains of S. aureus, S. epidermidis, B.subtillis, E.coli, T. mentagrophytes and M.gypseum. We observed that only the natrosol gel formulations with the extracts obtained from the turbolysis (F7, F13 and F15) presented results against the fungal strains studied, with F13 being able to inhibit C. tropicalis and C. krusei strains, and F15 only C. albicans strains, both with 512 μg / mL MIC. Thus, the present work was able to evaluate the antimicrobial activity of the banana peel ethanolic extracts, as well as the topical formulations, demonstrating that the extracts showed good antimicrobial activity, but this activity was inhibited or reduced when incorporated into the formulation. The stability study performed over the 60-day period showed good physicochemical stability of the tested formulation, in view of the pre-established temperature and time conditions. These data point to new researches with banana peels (Musa paradisíaca), seeking the development of formulations with discard products, and thus contributing to the sustainability of the environment.