Long-term curcumin treatment antagonizes masseter muscle alterations induced by chronic unpredictable mild stress in rats.

Abstract: Objective: To investigate the correlation between psychological stress and masseter muscle (MM) alterations, and explore the therapeutic agents for restoring the impaired masticatory muscle. Design: We established a chronic unpredictable mild stress (CUMS) animal model and observed the changes of ultrastructure, redox homeostasis and energy metabolism in MM in rats with and without curcumin treatment. Results: The depressive-like behavior in stressed rats was confirmed by the evidences of altered behaviors in sucrose preference test and open field test; while these phenomena were eased by curcumin. Except for the pathological changes in ultrastructure, decreased SOD, GSH-Px, CAT, Na+-K+ATPase, and Ca2+-Mg2+ATPase activities as well as increased MDA and LD content and LDH activity were also observed in MM in stressed rats. However, curcumin was capable of reversing CUMS-induced MM disorder by improving the activities of the examined anti-oxidant enzymes and energy metabolism enzymes. Additionally, the increased MDA content, LD content, and LDH activity in stressed rats were reduced by curcumin. Conclusion: All the findings indicate the adverse effects of CUMS on MM function in rats, and raise the possibility of developing curcumin as a potential therapeutic agent for psychological stress-induced masseter dysfunction. [Copyright &y& Elsevier]