Non-alcoholic Fatty Liver Disease: Beneficial Effects of Flavonoids.

Non-alcoholic fatty liver disease (NAFLD) has been known as the hepatic feature of metabolic syndrome. Extra fat depots, especially in visceral areas, develop insulin resistance as a result of mild oxidation and inflammation. Insulin resistance induces lipolysis and releases free fatty acids into the circulation, where they are transported to the liver. In the liver, free fatty acids are converted to triglycerides and accumulate, causing simple steatosis that, if left untreated, can lead to steatohepatitis, and subsequently liver necrosis and cirrhosis.Flavonoids, a group of plant compounds with incredible biological characteristics, have shown advantages in pathological conditions. Beneficial effects of flavonoids against NAFLD and its related disorders have been observed in both animal and human studies. Various mechanisms have been found for their protection. Flavonoids prevent hepatosteatosis by increasing fatty acid oxidation in the liver. They can also reduce caloric intake and decrease body weight and fat deposition in visceral tissues. Flavonoids are unique antioxidants that exert their beneficial effects through inhibition of nuclear factor κB, thereby attenuating release of inflammatory cytokines, which are triggers of insulin resistance. Finally, flavonoids have shown to increase adiponectin, improve insulin sensitivity and glucose tolerance, correct dyslipidemia, and reduce blood pressure in patients with NAFLD.