BACKGROUND: The aim of this study was to investigate the effects of lycopene (Lyc) on methotrexate (Mtx) induced liver toxicity in rats. METHODS: Twenty-eight male Sprague-Dawley rats were divided into four equal groups: control, Lyc, Mtx and Mtx-L: Control group: Rats were given only the vehicle. Lyc group: Rats were given Lyc (10 mg/kg) with corn oil by oral gavage for ten days. Mtx group: Rats were injected intraperitoneally with a single dose of 20 mg/kg of Mtx and given corn oil by oral gavage. Mtx-L group: Rats were post-treated with Lyc (10 mg/kg) for ten days after a single dose of Mtx (20 mg/kg). RESULTS: Mtx administration increased histopathological damage, TNF-α, IL-1β, TOS, TAS and OSI levels in tissues; AST, ALT levels in the blood. Sinusoidal dilatation, infl ammatory cell infi ltration and congestion were signifi cantly improved in the Mtx-L aon histopathologic examination of the rats. In Mtx-L group that were treated at the Lyc, TNF-α and IL-1β levels of liver tissue were decreased signifi cantly compared to Mtx group whereas the decrease in OSI was not signifi cant. Lyc treatment improved the AST and ALT values in Mtx-L group. But only AST improvement was signifi cant. CONCLUSIONS: The results of this study revealed that Lyc might be useful in protecting the liver from injury due to Mtx in rats by reducing the increased proinfl ammatory cytokine levels (Tab. 4, Fig. 1, Ref. 44). Text in PDF www.elis.sk.