Broad specificity alkaline proteases efficiently reduce the visual scaling associated with soap-induced xerosis

In xerotic skin, the proteolysis of desmosomes is reduced leading to the accumulation of corneocytes on the surface of the skin. The effect of proteases applied topically to soap-induced xerotic skin was evaluated using a five-point visual scale. The visual scaling associated with soap-induced xerosis could be ameliorated by the topical application of exogenous protease. Bovine pancreatic chymotrypsin, papain, and a bacterial protease from Bacillus licheniformis were all capable of facilitating the reduction in visual scaling in a short time. Alcalase and Optimase, both broad specificity alkaline bacterial proteases, were the most weight-efficient at delivering this clinical effect. The reduction in scaling could be achieved either by occluded application of an aqueous enzyme solution or by a two-step unoccluded application first of an aqueous enzyme solution followed by a commercial moisturizer. Morphological and immunological analysis of bacterial enzyme-treated skin revealed that topically applied protease specifically induced the degradation of the desmosomes thereby promoting desquamation. These results indicate that topical application of protease can significantly and rapidly reduce the visual scaling associated with soap-induced xerosis by promoting desmosome degradation within the corneocyte clumps.