Topical application of vitamin A reverses metaplasia of rat vaginal epithelium - A rapid and efficient approach to improve mucosal barrier function

Retinyl palmitate and its metabolites retinol and retinolc acid control gro wth and epithelial differentiation. Systemic or local vitamin A deficiency induced by malnutrition, continuous chemical irritation or locally induced by inflammation causes squamous metaplastic changes in the epithelium of mu cous membranes. We demonstrate that in an animal model topically applied re tinyl palmitate can be taken up by the mucosal cells independently from the systemic supply. Under in vivo conditions metabolic changes in vaginal epi thelium of rats were shown to be reversed by treatment with topical retinyl palmitate. After only two days treatment squamous metaplastic vaginal epithelium in ra ts shows a reversal of the epithelium into a normal phenotype which continu es after cessation of the treatment for 7 to 11 days. Higher concentrations and longer retention times lead to a statistically significant (p = 0.025) increase in the protection time. These data demonstrate that squamous chan ges induced by vitamin A deficiency can be totally reversed with topically applied retinyl palmitate.