Folic acid supplementation prevents high fructose-induced non-alcoholic fatty liver disease by activating the AMPK and LKB1 signaling pathways

BACKGROUND/OBJECTIVES: The present study aimed to evaluate the effects of folic acid supplementation in high-fructose-induced hepatic steatosis and clarify the underlying mechanism of folic acid supplementation. MATERIALS/METHODS: Male SD rats were fed control, 64% high-fructose diet, or 64% high-fructose diet with folic acid for eight weeks. Plasma glutamate-pyruvate transaminase, glutamate-oxaloacetate transaminase, lipid profiles, hepatic lipid content, S-adenosylmethionine (SAM), and S-adenosylhomocysteine (SAH) were measured. RESULTS: The HF diet significantly increased hepatic total lipid and triglyceride (TG) and decreased hepatic SAM, SAH, and SAM:SAH ratio. In rats fed a high fructose diet, folic acid supplementation significantly reduced hepatic TG, increased hepatic SAM, and alleviated hepatic steatosis. Moreover, folic acid supplementation in rats fed high fructose enhanced the levels of phosphorylated AMP-activated protein kinase (AMPK) and liver kinase B (LKB1) and inhibited phosphorylation of acetyl coenzyme A carboxylase (ACC) in the liver. CONCLUSIONS: These results suggest that the protective effect of folic acid supplementation in rats fed high fructose may include the activation of LKB1/AMPK/ACC and increased SAM in the liver, which inhibit hepatic lipogenesis, thus ameliorating hepatic steatosis. The present study may provide evidence for the beneficial effects of folic acid supplementation in the treatment of non-alcoholic fatty liver disease.