SIRT1 and obesity due to melanocortin 4 receptor deficiency: Brown alga ecklonia cava polyphenol extract has been demonstrated to reduce HFD-induced obesity and metabolic syndrome and might have potential anti-obesity effects via the regulation of hepatic lipid metabolism, inflammation, and oxidative stress through the activation of AMPK/Sirt1 and the regulation of its downstream genes in HFD-induced obese mice [69].