Pretreatment of trans-ferulic acid improved neurotoxicity in a thioacetamide-induced hepatic encephalopathy rat model; participation of the MAPK/NF-κb signaling pathway

Aim: Trans-ferulic acid (TFA), a naturally occurring phenolic compound, has attracted significant attention due to its strong hepatoprotective and neuroprotective properties. Despite extensive research on its overall biological activities, the specific mechanisms by which TFA influences hepatic encephalopathy (HE) remain unclear. This study aims to explore the therapeutic potential of TFA by examining its effects on inflammatory signaling, glial activation, and apoptotic pathways in a thioacetamide (TAA)-induced rat model of HE. Methods: Rats were separated into four groups: a normal control group, the TAA group (which received TAA at 300 mg/kg/day for 3 days), and groups pre-treated with TFA (at doses of 25/50 mg/kg, administered orally) for 10 days, with TAA administered from the eighth to the 10th day. Results: TFA pre-treatment effectively reduced TAA-induced biochemical disturbances, as shown by lower serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and ammonia. This biochemical improvement was complemented by a significant reduction in TAA-related hepatic histopathological damage. TFA also alleviated systemic inflammation by suppressing TAA-induced increases in pro-inflammatory mediators, including tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), while also elevating the anti-inflammatory cytokine IL-10. Consistent with these results, TFA further suppressed the activation of MAPK/NF-κB inflammatory signaling pathways in both liver and brain tissues and decreased glial fibrillary acidic protein (GFAP) expression in the brains of TAA-treated rats, indicating reduced neuroinflammation and astrocyte activation. Additionally, immunochemical analysis showed that TFA pre-treatment effectively prevented the TAA-induced increase in pro-apoptotic markers Caspase-3 and Bax in both liver and brain tissues. This study underscores the strong protective effects of TFA against TAA-induced HE, mainly through inhibition of MAPK/NF-κB signaling, suppression of astrocyte activation, and reduction of apoptosis. Conclusion: These outcomes imply that TFA could be an effective treatment for HE.