INS and obesity due to melanocortin 4 receptor deficiency: Nawaz et al. confirmed the ability of astaxanthin to stimulate mitochondrial function, where astaxanthin was shown to reduce insulin resistance in diet or myotubule-induced obesity in vitro by modulating insulin signaling in an antioxidant and antioxidant-independent manner and by activating mitochondrial energy metabolism via the activation of the AMP-activated protein kinase pathway (AMP) coactivator γ coactivator-1α (PGC-1α) peroxisome proliferator activated receptor in skeletal muscle [56].