PPARG and obesity due to melanocortin 4 receptor deficiency: Although many mechanisms of curcumin have been proposed for its effects on obesity and metabolic disorders, such as activation of peroxisome proliferator-activated receptor γ (PPARγ) [34], antioxidation [35], and suppression of p300 and nuclear factor-kappaB [36], the selective inhibition of 11β-HSD1 by curcumin could be another mechanism.