Gallic Acid Inhibits Lipid Accumulation via AMPK Pathway and Suppresses Apoptosis and Macrophage-Mediated...

Area of Science:

• Hepatology and Molecular Biology
• Natural Product Chemistry
• Immunology

Background:

• Nonalcoholic fatty liver disease (NAFLD) encompasses a spectrum from simple steatosis to nonalcoholic steatohepatitis (NASH).
• NASH pathogenesis involves hepatic steatosis, oxidative stress, apoptosis, and inflammation, often exacerbated by hepatocyte-macrophage crosstalk.
• Gallic acid (GA), a plant-derived polyphenol, shows promise for hepatic steatosis, but its molecular mechanisms require elucidation.

Purpose of the Study:

• To investigate the molecular mechanisms by which Gallic acid (GA) mitigates hepatic lipid accumulation, apoptosis, and inflammation.
• To examine GA's effects on hepatocyte-macrophage interactions relevant to nonalcoholic steatohepatitis (NASH) development.

Main Methods:

• Utilized HepG2 cells to assess GA's impact on palmitic acid (PA)-induced lipid accumulation and oxidative stress.
• Evaluated GA's effects on apoptosis markers and caspase 3/7 activity in response to PA and H2O2.
• Employed a co-culture system of Hepa 1-6 hepatocytes and RAW 264 macrophages to analyze inflammatory and antioxidant responses.

Main Results:

• Gallic acid (GA) attenuated palmitic acid (PA)-induced hepatic steatosis by activating AMP-activated protein kinase (AMPK) in HepG2 cells.
• GA improved cell viability and suppressed apoptosis-related gene expression and caspase 3/7 activity induced by PA and H2O2.
• In co-cultures, GA reduced pro-inflammatory mediators and enhanced antioxidant enzyme expression, indicating modulation of hepatocyte-macrophage crosstalk.

Conclusions:

• Gallic acid (GA) effectively suppresses hepatic lipid accumulation, apoptosis, and inflammation driven by hepatocyte-macrophage interactions.
• GA's activation of AMPK and its anti-inflammatory and antioxidant properties present a promising therapeutic avenue for preventing NASH and its complications.