The protective role of musk on salivary glands of mice exposed to chronic unpredictable mild stress.

ABSTRACT

This study assessed the impact of chronic unpredictable mild stress (CUMS) on the structure of mouse salivary glands and the role of musk in alleviating this impact. Forty male albino mice were distributed equally into four groups; control (untreated), CUMS (exposed to CUMS for 4 weeks), CUMS+fluoxetine (FLU) (exposed to CUMS then treated with FLU, CUMS+musk (exposed to CUMS then treated with musk). Behavioral changes and serum corticosterone levels were assessed at the end of the experiment. The submandibular and parotid glands were dissected out and processed for histopathological and immunohistochemical examination using antibodies against alpha smooth muscle actin (ASMA) and brain-derived neurotropic factor (BDNF). Exposure to CUMS significantly (P < 0.001) increased the serum corticosterone level and induced depression. CUMS also induced vacuolation in acinar cells along with a significant (P < 0.001) reduction of ASMA immunoexpression, indicating an effect on myoepithelial cells, and a significant (P < 0.001) increase of BDNF expression in the gland ductal system. Both FLU and musk alleviated the CUMS-induced behavioral, biochemical and histopathological changes in the salivary glands. In conclusion, musk ameliorates stress-induced structural changes in mouse salivary glands. This effect might be mediated through up-regulation of BDNF secretion by the glands.