Rosmarinic Acid Protects Against Acetaminophen-Induced Hepatotoxicity by Suppressing Ferroptosis and Oxidative Stress Through Nrf2/HO-1 Activation in Mice.

Liver injury caused by the irrational use of acetaminophen (APAP) represents a significant challenge in the field of public health. In clinical treatment, apart from N-acetylcysteine (NAC), the only approved antidote, there are extremely limited effective intervention measures for APAP-induced hepatotoxicity. Therefore, exploring novel liver-protecting drugs and elucidating their mechanisms of action is of great scientific significance and clinical value. Rosmarinic acid (RA), as a natural polyphenolic compound, has been proven to have significant antioxidant activity. Previous studies have shown that it has a protective effect against drug-induced liver injury. Nevertheless, the precise protective mechanism of RA in APAP-induced acute liver injury (AILI) has not been fully defined. This study was based on an AILI mouse model to systematically explore the liver-protecting effect of RA and its underlying molecular mechanisms. The research results showed that pretreatment with RA could notably mitigate liver pathological injury. It could decrease the activities of ALT and AST in the serum, suppress the liver inflammatory reaction, and reverse the decline in the levels of CAT, T-AOC, SOD, and GSH caused by APAP. Meanwhile, RA could enhance antioxidant defense capabilities by activating the Keap1/Nrf2/HO-1 signaling pathway, regulate the xCT/GPX4 axis to inhibit lipid peroxidation, and thus block the process of ferroptosis. In conclusion, this study confirmed that RA exerts a protective effect against AILI by regulating the Keap1/Nrf2/HO-1 axis to enhance antioxidant capacity and inhibit ferroptosis through the xCT/GPX4 pathway. Our research provides a theoretical basis for RA as a potential therapeutic agent for APAP-induced liver injury.