The Protective Effects of Origanum vulgare L. Extract on Genetic Damage of Cyclophosphamide in Mice Blood Lymphocytes Using Micronucleus Test

Background: Despite its various clinical applications, cyclophosphamide (CP), an alkylating chemotherapeutic agent, has demonstrated numerous side effects, including genetic toxicity. Objectives: This study investigated the protective action of Origanum vulgare L., a powerful antioxidant plant, on the genotoxicity of CP in the mice blood lymphocytes. Methods: The mice were pre-treated orally with different doses of 50, 100, 200, or 400 mg/kg O. vulgare ethanolic extract once a day for 7 consecutive days. One hour after the final dose of O. vulgare, each animal received a single intraperitoneal administration of 200 mg/kg CP. After 24 hours, the preventive effect of O. vulgare was evaluated using an in vitro micronucleus (Mn) test in cytokinesis-blocked lymphocytes, which is a reliable genotoxicity test. All doses of O. vulgare caused significant reductions in the CP-induced Mn formation, which served as an indicator of DNA damage in the peripheral blood lymphocytes. Results: The total reduction of the Mn in binucleated lymphocytes were 67% and 75% for doses of 200 and 400 mg/kg of O. vulgare, respectively (P