Curcumin protects thymus against D-galactose-induced senescence in mice

Senescence-related decline of thymus affects immune function in the elderly population and contributes to the prevalence of many relevant diseases like cancer, autoimmune diseases, and other chronic diseases. In this study, we investigated the therapeutic effects of curcumin, an agent that could counter aging, and explored its optimal intake and the alteration of autoimmune regulator (Aire) after curcumin treatment in the D-galactose (D-gal)-induced accelerated aging mice. ICR mice were intraperitoneally injected with D-gal for 8 weeks to establish the accelerated aging model and given curcumin with 50, 100, and 200 mg/kg body weight per day by gavage, respectively, for 6 weeks. It indicated that the D-gal-treated mice developed structural changes in the thymi compared with the control group without D-gal and curcumin treatment. As the supplements of curcumin, it resulted in a restoration of the normal thymic anatomy with an increase of proliferating cells and a reduction of apoptotic cells in the thymi of the D-gal-induced aging model mice. Curcumin administration could also expand the expression level of Aire from mRNA level and protein level. The current study demonstrated that curcumin could ameliorate senescence-related thymus involution via upregulating Aire expression, suggesting that curcumin can rejuvenate senescence-associated alterations of thymus induced by D-gal accumulation.