Purification et caractérisation des protéases de bouses de vache: Validation d’un vieux traitement empirique Africain des brûlures

Mankind has for many years relied on home remedies to manage ailments and injuries, including burn wounds. Wound healing is generally regarded as a natural process, with interventions such as ointment application regarded as assisting the process. Amongst other strategies, cow dung is a home remedy used by many African communities to manage burn wounds. The current study was aimed at the detection, purification and characterization of proteases from cow dung as validation for its usage in the management of burn wounds amongst African communities. Cow dung was collected around Pretoria, South Africa, and homogenized with a blender in a phosphate buffer, pH 7. The crude protein was obtained using ammonium sulphate precipitation and purified using size exclusion, anion exchange and cation exchange chromatographic techniques. Enzyme activity was determined using the casein digestion method. The purified proteases were characterized according to temperature and pH as well as substrate specificity. Three protease fractions were purified from cow dung homogenate. Fraction H was found to have an optimum temperature of 40˚C, an optimum pH of 6 and affinity for elastin; Fraction I was found to have an optimum temperature of 35˚C, an optimum pH of 7 and affinity for haemoglobin; and Fraction J was found to have an optimum temperature of 35˚C, an optimum pH of 8 and affinity for collagen. The findings of the study therefore suggest that the presence of proteases in cow dung could be one of the contributing factors towards its effectiveness in traditional African burn wound management.