Objective:To evaluate the ameliorative role of grapefruit juice on the cytogenetic and testicular damage induced by the antiarrythmic drug amiodarone in albino rats.Methods:Animals were divided into four groups.Group I was considered as control.Group II was given grapefruit juice at a dose level of 27 mL/kg body weight.Group III was orally administered amiodarone(18 mg/kg body weight)daily for 5 weeks.Animals were sacrificed after 5 weeks of treatment.Bone marrow was collected from the femurs for analysis of chromosomal aberrations and mitotic indices.Testes were removed and stained with H&E for histological examination.Sperms were collected from epidedymis for detection of sperm head abnormalities.Comet assay was used to detect DNA damage.Results:Amiodarone treatment caused a significant increase in the percentage of chromosomal aberrations,decreased the mitotic index and increased DNA damage.The testis showed many histopathological alterations,inhibition of spermatogenesis and morphometric changes.The number of sperm head abnormalities was increased.Treating animals with amiodarone and grapefruit juice caused a reduction in chromosomal aberrations,mitotic index,DNA damage and testicular alterations caused by amiodarone.Conclusions:The results of this study indicated that grapefruit juice ameliorates the cytotoxicty and testicular alterations induced by amiodarone in albino rats and this is may be due to the potent antioxidant effects of its components. Objective: To evaluate the ameliorative role of grapefruit juice on the cytogenetic and testicular damage induced by the antiarrythmic drug amiodarone in albino rats. Methods: Animals were divided into four groups. Group I was considered as control. Group II was given grapefruit juice at a The dose level of 27 mL / kg body weight. Group III was orally administered with amiodarone (18 mg / kg body weight) daily for 5 weeks. Animals were sacrificed after 5 weeks of treatment. Bone marrow was collected from the femurs for analysis of chromosomal aberrations and mitotic indices. Tips were removed and stained with H & E for histological examination. Sperms were collected from epidedymis for detection of sperm head abnormalities. Metht assay was used to detect DNA damage. Results: Amiodarone treatment caused a significant increase in the percentage of chromosomal aberrations , decreased the mitotic index and increased DNA damage.The testis showed many histopathological alterations, inhibition of spermatogenesis and morpho metric changes. the number of sperm head abnormalities was increased.Treating animals with amiodarone and grapefruit juice caused a reduction in chromosomal aberrations, mitotic index, DNA damage and testicular alterations caused by amiodarone.Conclusions: The results of this study show that grapefruit juice ameliorates the cytotoxicty and testicular alterations induced by amiodarone in albino rats and this is may due due to the potent antioxidant effects of its components.