Rutaecarpine Aggravates Acetaminophen-Induced Acute Liver Injury by Inducing CYP1A2

In this study, we investigated whether rutaecarpine could aggravate acetaminophen-induced acute liver damage in vivo and in vitro. CCK-8 and apoptosis assays were performed to verify the cytotoxicity of acetaminophen to L02 cells with or without rutaecarpine. The expression levels of the target proteins and genes were determined using Western blotting and qRT-PCR. The liver pathological changes were evaluated with hematoxylin and eosin staining, while the aspartate aminotransferase (AST) and alanine aminotransferase (AST) levels in plasma were measured to assess the liver damage. Our results revealed that pretreatment of the cell and mice with rutaecarpine significantly aggravated the acetaminophen-induced liver damage. Mechanistically, rutaecarpine induces the CYP1A2 protein, which accelerates the metabolism of acetaminophen to produce a toxic intermediate, N-acetyl-p-benzoquinone imine (NAPQI), leading to severe liver inflammation. Rutaecarpine exacerbated the liver damage by upregulating CYP1A2 and proinflammatory factors. These findings highlight the importance of carefully considering the dosage of rutaecarpine when combined with acetaminophen in drug design and preclinical trials.