α-Lipoic Acid Alleviates Non-Alcoholic Fatty Liver Disease by Elevating Chaperone-Mediated Autophagy and Increasing β-Oxidation via AMPK-TFEB Axis.

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a prevalent chronic liver disorder associated with impaired lipid metabolism and oxidative stress. As a natural antioxidant and dithiol compound, α-lipoic acid (ALA) may play a beneficial role in modulating hepatic metabolism. This study investigates the potential mechanisms through which ALA may alleviate NAFLD.

METHODS

To construct an NAFLD model, NCTC 1469 cells were exposed to oleic acid and palmitic acid (OA/PA) and glucose for 24 h. RT-qPCR, Western blotting, and siRNA analyses were used to examine the effects and mechanisms of ALA. In vivo, C57BL/6J mice were fed a high-fat diet for 11 weeks and treated with ALA (200 mg/kg/day, intragastrical) for 4 weeks to evaluate its impact on NAFLD.

RESULTS

In NCTC 1469 cells exposed to OA/PA and glucose, ALA markedly reduced lipid accumulation by activating TFEB, which in turn promoted fatty acid β-oxidation and chaperone-mediated autophagy (CMA). Furthermore, ALA activated NRF2-dependent CMA and mitigated oxidative stress. Inhibition of AMPK or silencing of TFEB/NRF2 abolished these effects, indicating the key role of the AMPK-TFEB/NRF2 axis. In HFD-fed mice, ALA alleviated hepatic steatosis, serum lipid abnormalities, and liver injury, consistent with its activation of CMA and β-oxidation and reduction in oxidative stress via this pathway.

CONCLUSIONS

ALA synchronously activates CMA, β-oxidation, and antioxidant responses via a unified AMPK pathway to reduce lipid accumulation and oxidative stress, providing a mechanistically integrated therapeutic strategy for NAFLD.