Evaluation of the Dose-Response Relationship of Ethanol Extract from Cassia rhombifolia L. Fruits in a Murine Model of CCl₄-Induced Hepatotoxicity

Plant‐based therapeutics offer a promising strategy for managing liver disorders associated with oxidative stress and inflammation. This study evaluated the dose-dependent hepatoprotective effects of an ethanol extract from Cassia rhombifolia L. fruits (CREE) in a murine model of carbon tetrachloride (CCl₄)-induced liver injury. Mice received CREE orally at 100, 200, or 300 mg/kg once daily for 8 weeks, while hepatotoxicity was induced by intraperitoneal CCl₄ injections twice weekly. Physiological indices, liver function biomarkers [aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), total bilirubin], oxidative stress markers [malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT)], and pro-inflammatory cytokines [tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6)] were quantified, and liver histology was assessed. Dose-response relationships were analyzed using regression and correlation models. CREE produced significant, dose-dependent improvements in body weight, liver index, and liver function tests, along with reduced MDA levels and restoration of SOD and CAT activities. Circulating TNF-α, IL-1β, and IL-6 concentrations decreased progressively with increasing CREE dose. Histopathological examination revealed a graded restoration of hepatic architecture, with a near-normal appearance at 300 mg/kg. Acute oral toxicity testing showed no adverse effects at doses up to 3,000 mg/kg, indicating a favorable safety margin. Overall, these findings demonstrate that CREE confers dose-dependent hepatoprotection through coordinated antioxidant, anti-inflammatory, and cytoprotective mechanisms, supporting its potential as a safe, multi-target phytotherapeutic candidate for chemical-induced liver injury.