The effect of dietary curcumin intake on age associated neurobehavioral dysfunction

We hypothesized a combination treatment of dietary curcumin and CR to improve age associated neurobehavioral dysfunction better than either treatment alone, via attenuation of inflammation and oxidative stress. Middle- aged (15 months) and aged (20 months) male and female C57BL/6 mice were grouped under four dietary interventions, (1) regular chow fed ad libitum (AL), (2) curcumin at 0.7g/kg body weight in AL (CURAL), (3) caloric restriction (CR) and (4) curcumin w/ CR (CURCR) and were kept under these interventions for 16 weeks. We administered a behavioral battery after eight weeks of dietary intervention that included tests for cognitive and psychomotor function. To measure oxidative stress and inflammation we collected plasma and red blood cells and used factory manufactured kits to detect pro and anti-inflammatory cytokines and glutathione status. CR and CURCR significantly improved various aspects of motor function including wire suspension, rotorod and bridge walking performance, indicative of cerebellum functioning, when compared to age matched control (AL) for both sexes, whereas only CURAL improved optomotor function, indicative of vision, in middle aged males and females and aged males. All three interventions had significant effects on pro and anti-inflammatory cytokines, KC-GRO concentration was significantly decreased in CR and CURCR in the middle aged males and aged females group and was correlated to body weight; TNF-α concentration was significantly decreased in both CURAL and CURCR in middle aged males and there was a significant decrease in C-reactive protein in aged males under CURCR. There were no significant differences in the redox state across groups. Based on results from the motor tests and blood based biomarkers and earlier data on cognitive function, dietary curcumin can be used as a CR mimetic for certain components of healthy functional aging but the benefits may not entirely be related to its anti-inflammatory and anti-oxidant effects. Future studies should include different doses and a tapered down caloric restriction regimen.