Beta-caryophyllene restores liver–brain axis integrity in thioacetamide-induced hepatic encephalopathy: Behavioral and molecular insights

Hepatic encephalopathy (HE) is a severe neuropsychiatric complication of liver dysfunction, driven by hyperammonemia, oxidative stress, neuroinflammation, apoptosis, and endoplasmic reticulum (ER) stress, which disrupt the hepato-encephalic axis and impair cognition and motor functions. Despite its clinical burden, effective therapies that target this multi-organ pathology remain limited. β-Caryophyllene (BCP), an antioxidant and anti-inflammatory dietary sesquiterpene, has not been evaluated for its ability to modulate liver–brain crosstalk in HE. This study investigated the hepatoprotective and neuroprotective effects of BCP in a rat model of thioacetamide (TAA)-induced HE. Rats received TAA (200 mg/kg, i.p.) for three days, followed by BCP (100–400 mg/kg) for 14 days. A comprehensive evaluation included serum biochemistry, oxidative stress indices, inflammatory cytokines, apoptosis-related proteins, neurotrophic factors (BDNF), astroglial activation marker (GFAP), ER stress regulators (GRP78, IRE1, XBP1, PERK, CHOP, ATF6), histopathology, and behavioral outcomes. TAA caused severe hepatic and cerebral injury with elevated liver enzymes, oxidative and inflammatory mediators, ER stress dysregulation, pro-apoptotic signaling, reduced BDNF and GFAP, and impaired motor and exploratory behaviors. BCP treatment dose-dependently restored biochemical and molecular parameters, suppressed oxidative stress and neuroinflammation, normalized ER stress signaling, promoted anti-apoptotic pathways, preserved BDNF and maintained astroglial status as reflected by GFAP, and improved histoarchitecture. Importantly, moderate to high doses fully restored locomotor and exploratory activity, indicating coordinated protection across the hepato-encephalic axis. Here, for the first time, the BCP concurrently mitigates hepatic and cerebral pathology via oxidative, inflammatory, apoptotic, and ER stress pathways, supporting its translational potential as a dual hepatoprotective and neuroprotective candidate for xenobiotic-induced HE and related liver–brain disorders.