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

To investigate the correlation between psychological stress and masseter muscle (MM) alterations, and explore the therapeutic agents for restoring the impaired masticatory muscle.

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.

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 Ca(2+)-Mg(2+)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.

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.