Effect of CR and spice compounds on splenocyte proliferation. Splenocytes were stimulated with T cell mitogen Con A or PHA, or anti-CD3/CD28 at their optimal concentrations (1.5, 5, 5/1 μg/ml, respectively) for 72 h, and proliferation were determined by [3H]-thymidine incorporation. Values are means ± SEM (n = 9 mice/group). Means without a common letter differ at P < 0.05. HFD: high fat diet, CR: caloric restriction, C: curcumin, P: piperine.