NLRP3 Inflammasome Activation Is Involved in Geniposide-Induced Hepatotoxicity

Background: Geniposide, a prominent iridoid glycoside derived from Gardenia jasminoides J. Ellis, has garnered attention due to its association with hepatotoxicity despite its well-documented pharmacological efficacy in preclinical and clinical contexts. The NOD-like receptor protein 3 (NLRP3) inflammasome is implicated in numerous pathological conditions, including drug-induced liver injury. This study aims to explore the involvement of the NLRP3 inflammasome in geniposide-induced liver toxicity. Methods: Rats were administered geniposide for 5 days, concurrently treated with or without glibenclamide (GLY), an in vivo inhibitor of NLRP3. In vitro, HL-7702 cells were exposed to genipin (a metabolite of geniposide via hepatointestinal circulation), with or without GLY supplement. Liver tissue was examined through pathological sections. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), γ-glutamyl transpeptidase (γ-GT), and total bilirubin (T-Bil) levels were determined using the enzyme plate method. IL-1β and IL-18 levels in the supernatant and serum were quantified through ELISA. Apoptosis-associated speck-like protein (ASC), NLRP3, caspase-1, pro-IL-1β, and pro-IL-18 mRNA levels in cells or the liver were assessed by RT-PCR. Protein levels of ASC, NLRP3, caspase-1, pro-IL-1β, and pro-IL-18 in cells or the liver were analyzed by Western blot. Results: Rats treated with geniposide displayed notable liver damage characterized by inflammatory infiltration, elevated serum transaminases, and heightened levels of inflammatory factors IL-1β and IL-18. This liver damage was concomitant with NLRP3 inflammasome activation within the liver. Furthermore, genipin induction led to reduced cell viability, increased transaminases in the cell supernatant, and an upsurge in inflammatory factors, resulting in heightened NLRP3 inflammasome expression within the cells. However, GLY effectively curtailed excessive NLRP3 activation, dampened the production of inflammatory factors IL-1β and IL-18, and ameliorated liver damage caused by geniposide. Conclusions: Our findings collectively elucidate that geniposide induces hepatotoxicity by triggering NLRP3 inflammasome signaling. Inhibition of the inflammasome presents a promising novel therapeutic target for mitigating geniposide-induced hepatotoxicity.