Aims and Objectives : Other species of cleome have showed hepato protective properties but there is no study on safety profile and xenobiotic induced hepato protective activities of Cleome brachycarpa which have showed many other pharmacological properties .This study aimed to evaluate the acute and subchronic oral toxicity of the hydroalcoholic extract of the aerial parts of Cleome brachycarpa to provide its safe dose and to compare the possible antioxidant and hepato protective potentials on acetaminophen-induced hepatotoxicity with Silybum Marianum as an approved hepatoprotective agent in global markets.

Method and Materials: After providing the hydroalcoholic extract, acute and repeated doseoral toxicity assessments were performed by OECD 425 and 407guidelines. In hepatoprotection assessments, animals were divided to 4 gorups for 6 days interventions.Negative and positive controls received 10 ml/kg normal saline and 500 mg/kg acetaminophen respectively .In 2 treatment groups animals received 100 mg/kg from the hydroalcoholic extract of C.brachycarpa and 200 mg/kg Silybum marianum (Silymarin) extract .All treatment groups received 500 mg/kg acetaminophen on the 5th day, one hour after the last pretreatment with two different hepato protective agents. On the 6th day, liver injuries and the quality of hepato protection were assessed by ALT, AST, ALP, SOD, CAT, and MDA in liver tissues and histopathologicalstudies.

Results: Acute test didn't show any sign of toxicity in doses up to 5000 mg/kg and in repeated dose test, no sign of organ toxicity was detected in doses up to 250 mg/kg .Pretreatment with C. brachycarpa extract (100 mg/kg) exhibited a significant reduction in ALT, AST, ALP and MDA (p < 0.05) levels when compared with the acetaminophen-only treated group. At the same time, pretreatment with C.brachycarpa extract (100 mg/kg) aused a significant increase in the levels of SOD and Catalase (p ? 0.05) in comparison to the acetaminophentreatedgroup. Silymarin treated mice showed similar effects except for Catalase levels which were better controlled by C. brachycarpaextract. The complete histopathological study and liver scores confirmed the biochemical data.

Conclusion: This study has revealed the safety and hepato protective effects of Cleome brachycarpa herbal extract as a possible new pharmaceutical dosage form for future studies which could be considered as a new effective supplement in xenobiotics-induced liver damages.