Effect of aqueous areca nut extract on the permeability of mucosa
The adverse effects associated with areca (betel) nut chewing, including oral submucous fibrosis (OSF) and oral cancer, are well known. In the etiology of these diseases, components of the nut have to penetrate the epithelial barrier to reach the connective tissue. Since human vaginal mucosa is similar to oral mucosa with respect to histology and permeability to water, we decided to investigate the effects on permeability of vaginal mucosa in the presence of areca nut extract. Specimens of fresh clinically healthy vaginal mucosa (n = 12) were taken from excised tissue obtained during vaginal hysterectomies. Seven biopsies from each specimen (n = 6) were mounted in flow-through diffusion cells (exposed area 0.039 cm2) and their permeability to 3H2O determined in the presence of 1% aqueous baked areca nut extract using a continuous flow-through perfusion system. The six remaining specimens were used as controls. Specimens were examined histologically before and after permeability experiments. Mean steady state flux values (± s.e.m.) (8-20 h) of 1923 ± 2 and 2262 ± 9 cpm min-1 cm-2 were obtained in the presence and absence (control) of areca nut extract, respectively. Although no statistically significant differences (Kruskal-Wallis test) between these flux values were found, the presence of areca nut extract lowered the mean mucosal permeability by about 20% when compared to the control specimens. We propose that the astringent action of the tannins present in areca nut extract alters the barrier properties of the epithelium, a factor which may play a role in the deleterious effects on oral mucosa.