ORIGINAL ABSTRACT

Glyphosate (GLY) is a widely used herbicide active ingredient applied in agricultural, residential, and public areas. Although the European Chemicals Agency has stated that current evidence is insufficient to classify GLY as an endocrine disruptor, increasing experimental data indicate that GLY may induce organ toxicity. This study aimed to investigate glyphosate-induced liver toxicity and to evaluate the potential protective effects of eugenol in a rat model. Eugenol is a phenolic compound predominantly found in clove oil (Syzygium aromaticum L.) and is known for its antioxidant, anti-inflammatory, antimicrobial, and analgesic properties. It is classified as generally recognized as safe (GRAS) and non-mutagenic by the World Health Organization. Thirty-five male rats were randomly assigned to five groups: Control, EU-100, GLY, GLY + EU-50, and GLY + EU-100. All treatments were administered orally by gavage. Oxidative stress markers (lipid peroxidation, reduced glutathione, and superoxide dismutase), liver enzyme activities (ALT, AST, and ALP), and the expression of genes involved in antioxidant defense, apoptosis, and inflammation (HO-1, Nrf2, CAT, GPx, Bax, Caspase-3, Bcl-2, COX-2, NF-κB, IL-6, TNF-α, and IL-1β) were analyzed. Short-term GLY exposure resulted in oxidative imbalance, inflammatory activation, and apoptosis in hepatic tissue. Eugenol administration significantly alleviated these alterations by enhancing antioxidant defenses, activating the Nrf2/HO-1 signaling pathway, and suppressing pro-inflammatory responses. These findings suggest that eugenol may represent a promising natural hepatoprotective agent against glyphosate-induced liver toxicity.