Life Science Journal 2013;10(4) http://www.lifesciencesite.com 1629 Role of Nigella Sativa Seeds on modulation testicular toxicity of colchicine repeated use in adult albino rats Said S. Elshama 1,5 , Gaber M. G. Shehab 2,6 , Ayman E. El-Kenawy 3,7 , Hosam-Eldin H. Osman 4,8 , Mostafa M. Farag 2,6 . Department of Forensic Medicine and Clinical Toxicology 1 , Department of Biochemistry 2 , Department of Pathology 3 , Department of Anatomy 4 , College of Medicine, Taif University, kingdom Saudi Arabia. Department of Forensic Medicine and Clinical Toxicology, Suez Canal University, Egypt 5 . Department of Biochemistry, Faculty of Agriculture, Cairo University, Egypt 6 . Department of Molecular Biology. Genetic Engineering and Biotechnology Inst., Menoufiya University, Egypt 7 . Department of Anatomy, Al-Azhar University, Egypt 8 . Corresponding author: Said S. Elshama: saidelshama@yahoo.com . Abstract：Introduction: Gout is one of the most common diseases among humans in the world. Colchicine is an important drug for the treatment of this disease. Colchicine has a narrow therapeutic index; its poisoning is serious and associated with high mortality rate. Nigella sativa seeds are used for treatment of many diseases in traditional medicine. Aim of the study: Investigation of the role of nigella sativa seeds on modulation toxic effect of colchicine in the testis of rats. Materials and Methods: 120 of male adult albino rats divided into three equal groups (each n = 40). First group (control) received distilled water daily; the second was given 2mg / kg/day of colchicine. Third group was given 2 mg/kg/day of cholchicine with 1000 mg/kg/day of aqueous suspension of powdered nigella sativa seeds. Administration of drug and aqueous suspension were achieved by gastric gavage for 12 weeks. Testicular toxicity was investigated by assessment of histopatholgical changes, plasma testosterone level and semen analysis. Results: Repeated use of colchicine induced testicular toxicity manifested by histopathological changes such as marked degeneration of seminiferous tubules germinal cells, interstitial cells of Leydig and spermatid in the form irregular acrosomal cap with degenerated sperms, swollen vacuolated mitochondria and periphery clumped chromatin particles in cytoplasm of spermatogonia with low positive reaction of PAS. It led to decrease of testosterone plasma level, normal sperm count, sperm motility and liveability with increase of abnormal sperm count. Administration of Nigella sativa seeds with colchicine induced significant improvement of testicular toxicity manifestations Conclusions: Repeated use of colchicine caused testicular toxicity of rats which was improved by administration of nigella sativa seeds. [Said S. Elshama, Gaber M. G. Shehab, Ayman E. El-Kenawy, Hosam-Eldin H. Osman, Mostafa M. Farag. Role of Nigella Sativa Seeds on modulation testicular toxicity of colchicine repeated use in adult albino rats. Life Sci J 2013;10(4):1629-1639]. (ISSN:1097-8135). http://www.lifesciencesite.com . 216 KEYWORDS: Nigella sativa, colchicine, testis 1. Introduction Colchicine is a natural alkaloid with weak anti- inflammatory activity. It has been used extensively for gout treatment from centuries and also been recommended in preventing attacks of familial Mediterranean fever, treatment of primary biliary cirrhosis; amyloidosis and condyloma acuminate (Guven et al., 2002). It is an anti-mitotic agent and can be either cytotoxic or protective against cytotoxicity, but it has a direct toxicity on cells of skeletal muscle. Colchicine has been reported to protect against a variety of hepatotoxic insults and improve survival in a clinical trial for alcoholic cirrhosis (Maxwell et al., 2002). Colchicine is rapidly absorbed from the gastrointestinal tract after ingestion. It undergoes significant first pass hepatic metabolism, which primarily involves deacetylation. Subsequent to this, the metabolites undergo widespread enterohepatic recirculation before being excreted in bile and faeces (Borron et al., 1996). The symptoms of gastrointestinal toxicity of colchicine such as nausea, vomiting, diarrhea and abdominal pain are seen in 80% of patients on full therapeutic doses and are used as the clinical endpoint in dose titration (Milne and Meek, 1998). Nigella sativa is a plant of Ranunculaceae family that grows spontaneously and widely in several Southern Mediterranean and Middle Eastern countries. Its seed has over 100 different chemical constituents, including abundant sources of all the essential fatty acids. Although it is the oil that most often used medicinally, the seeds are a bit spicy and often used whole in cooking curries, pastries and Mediterranean cheeses (Hajhashemi et al., 2004). Nigella sativa seeds are used extensively in traditional medicine of many countries. It has been used for treatment of many diseases owing to the reported antiviral, anti- inflammatory, anti-schistosomiasis and immunomodulatory activities (Uz et al., 2008). Furthermore, it was found that nigella sativa extract has anti-tumor properties attenuating toxic side effects caused by several chemotherapeutic agents and protects against gentamicin-induced nephrotoxicity (Yaman