fig2

Figure 2. Mechanisms of the effects of astaxanthin on NASH. The strong antioxidant effect of astaxanthin can significantly inhibit oxidative stress, thereby reducing mitochondrial damage and endoplasmic reticulum stress, leading to a shift to M2 macrophage polarization and ultimately reversing liver steatosis, inflammation, and insulin resistance. Moreover, astaxanthin can reduce the activation of hepatic stellate cells to ameliorate hepatic fibrosis as a result of M1/M2 macrophage transformation. In addition, astaxanthin can inhibit the generation of hepatocyte tumors. Thus, astaxanthin prevents the development of NAFLD by inhibiting lipid accumulation, inflammation, and fibrosis in the liver. NAFLD: Nonalcoholic fatty liver disease; NASH: nonalcoholic steatohepatitis; KC: Kupffer cell; M1: proinflammatory macrophages; M2: anti-inflammatory macrophages; HSC: hepatic stellate cells; HCC: hepatocellular carcinoma.