5-O-Demethylnobiletin Alleviates CCl₄-Induced Acute Liver Injury by Equilibrating ROS-Mediated Apoptosis and...

Area of Science:

• Pharmacology
• Hepatology
• Natural Product Chemistry

Background:

• Polymethoxyflavanoids (PMFs) possess diverse therapeutic properties.
• 5-O-Demethylnobiletin (5-DN) is a PMF with known anti-inflammatory activity.
• The hepatoprotective role of 5-DN remained unexplored.

Purpose of the Study:

• To investigate the potential hepatoprotective effects of 5-DN against carbon tetrachloride (CCl4)-induced liver injury.
• To elucidate the underlying mechanisms of 5-DN's action in liver protection.

Main Methods:

• In vitro cytotoxicity and protective assays using HepG2 cells against CCl4.
• In vivo study involving CCl4-induced acute liver injury in BALB/c mice.
• Co-administration of 5-DN (1 and 2 mg/kg) via oral gavage for 15 days.
• Assessment of liver function markers (AST, ALT), histological changes, oxidative stress (ROS), CYP2E1 expression, apoptosis markers, and autophagy markers (LC3).

Main Results:

• 5-DN showed minimal cytotoxicity to HepG2 cells and protected them from CCl4-induced death.
• In vivo, 5-DN treatment significantly attenuated elevated AST/ALT levels and ameliorated CCl4-induced hepatic inflammation and fibrosis.
• 5-DN counteracted CCl4-induced oxidative stress, downregulated CYP2E1 expression, and enhanced antioxidant enzymes.
• It inhibited CCl4-induced cell proliferation and inflammatory pathways.
• 5-DN reduced apoptosis by modulating Bcl-2, Bax, Bid, caspase, and apaf-1 expression.
• Autophagic flux was promoted by 5-DN treatment, indicated by LC3 conversion.

Conclusions:

• 5-O-Demethylnobiletin (5-DN) exhibits significant hepatoprotective effects against CCl4-induced liver injury.
• 5-DN mitigates liver damage, inflammation, and fibrosis through antioxidant, anti-apoptotic, and pro-autophagic mechanisms.
• Its ability to downregulate CYP2E1 and enhance antioxidant defense is crucial for its protective action.