Abstract: A method for disrupting epithelial barrier function in a host in need of the topical administration of a physiologically active substance which comprises applying to the epithelium of the host, barrier-disrupting amount of at least one agent selected from the group consisting of an inhibitor of ceramide synthesis, inhibitor of acylceramide synthesis, inhibitor of glucosylceramide synthesis, and inhibitor of sphingomyelin synthesis, an inhibitor of fatty acid synthesis, an inhibitor of cholesterol synthesis, a degradation enzyme of ceramides, acylceramide, glucosylceramides, sphingomyelin, an inhibitor of phospholipid, glycosphingolipid, including glucosylceramide, acylceramide or sphingomyelin degradation, and both inhibitors and stimulators of metabolic enzymes of free fatty acids, ceramide, and cholesterol, as well as a topical composition useful therefor are disclosed.

Abstract: The invention herein encompasses methods effective to stimulate epithelial cell proliferation and/or enhance epithelial moisturization and lubrication in a mammalian subject utilizing a composition comprising one or more inhibitors of &bgr;-glucosidase activity or &bgr;-glucocerebrosidase activity. The composition of the method may alternatively comprise a glycosphingolipid, particularly glucocerebroside, or a combination of the above inhibitor(s) and a glycosphingolipid. The method is effective to enhance the cosmetic appearance of skin and promote healing of skin and mucous membranes damaged or deficient from aging, traumatic wounds, photo-aging and a variety of atrophic conditions.

Abstract: A method for disrupting epithelial barrier function in a host in need of the topical administration of a physiologically active substance which comprises applying to the epithelium of the host, barrier-disrupting amount of at least one agent selected from the group consisting of an inhibitor of ceramide synthesis, inhibitor of acylceramide synthesis, inhibitor of glucosylceramide synthesis, and inhibitor of sphingomyelin synthesis, an inhibitor of fatty acid synthesis, an inhibitor of cholesterol synthesis, a degradation enzyme of ceramides, acylceramide, glucosylceramides, sphingomyelin, an inhibitor of phospholipid, glycosphingolipid, including glucosylceramide, acylceramide or sphingomyelin degradation, and both inhibitors and stimulators of metabolic enzymes of free fatty acids, ceramide, and cholesterol, as well as a topical composition useful therefore are disclosed.