12 Toxicol. Environ. Health. Sci. Vol. 9(1), 12-22, 2017 1,4-Dinitrobenzene (1,4-DNB) is a synthetic com- pound used in explosives, dyes, organic chemicals and the plastic industry. Oral and dermal exposure is a likely route for industrial workers and people living near ammunition plants. This study investigated the effect of 1,4-DNB on testicular and spermatozoan antioxidant systems as well as sperm characteristics of Wistar rats. Oral exposure of male Wistar rats to 50 or 75 mg/kg, or dermal exposure to 1000 or 2000 mg/kg, of 1,4-DNB for 14 days increased spermic and testicular hydrogen peroxide and lipid peroxida- tion levels accompanied by decreased activities of enzymic antioxidants. Exposure to 1,4-DNB also resulted in decrease in body weight gain, reduced testicular and epididymal weights, epididymal degeneration, decrease in sperm quantity and quali- ty, and mild congestion of interstitial vessels and edema in the testes. These results reveal that indi- viduals unduly exposed to 1,4-DNB risk induction of oxidative stress in the epididymis and testis, and associated reproductive deficits. Keywords: Antioxidant systems, Dinitrobenzene, Epididy- mis, Oxidative stress, Testis, Spermatozoa Introduction Reproductive toxicity is a hazard often associated with chemical substances that interfere with normal re- production. It includes adverse effects on sexual func- tion and fertility in adult males and females, as well as developmental toxicity in the offspring. A reproductive toxicant may interfere with the sexual functioning or re- productive ability of exposed individuals from puberty throughout adulthood. Spermatogenesis 1 and Leydig cells 2,3 are vulnerable to oxidative stress. Oxidative stress or redox imbalance is one of the main causes of male infertility and has been implicated in many dis- eases resulting from high concentrations of free radi- cals and suppressed antioxidant potential, which may alter the proper functioning of the spermatozoa 4 . Oxidative stress in the male reproductive tract is as- sociated with negative changes in spermatozoa con- centration, motility, and morphology which may lead to poor semen parameters and ultimately infertility 5,6 . Male infertility could result from dysfunction at vari- ous levels along the hypothalamic-pituitary-gonadal axis such as damage at the hypothalamus or pituitary level, failure of the testes and obstruction or inflamma- tion of the testes 7 . However, Tremellen 8 and Shekarriz et al. 9,10 have shown that about 30-80% of male factor infertility cases are due to ROS-mediated sperm dam- age. Dinitrobenzenes are isomeric derivatives of benzene substituted with nitro groups in the ortho (1,2-dinitro- benzene), meta (1,3-dinitrobenzene), and para (1,4- DNB) positions 11 . They have been detected as envi- ronmental and industrial contaminants/toxicants of groundwater and soil near sites of trinitrotoluene pro- duction; waste disposal sites and military munitions test grounds 12 . Skin irritation, liver damage, and ane- mia are commonly observed among munitions work- ers exposed to dinitrobenzenes 13 . The main uses of 1,4-DNB, one of the isomers of dinitrobenzene, are in the manufacture of various dyes, plastics, explosives, organic chemicals and in the production of trinitrotolu- ene. Oral and dermal exposures are the most likely routes for people living near ammunition plants and for industrial workers and this should elicit concern as many of these categories of industries are in Nigeria and other developing countries with poor industrial Janet Olayemi Sangodele 1,2,3 , Mary Tolulope Olaleye 1 , Thomas K. Monsees 2 & Afolabi Clement Akinmoladun 1 1 Phytomedicine, Biochemical Pharmacology and Toxicology Laboratories, Department of Biochemistry, School of Sciences, PMB 704, The Federal University of Technology, Akure, Nigeria 2 Department of Medical Biosciences, Faculty of Natural Science, University of the Western Cape, Bellville, Cape Town, South Africa 3 Department of Biochemistry, Bingham University, PMB 005, Karu, Nasarawa State, Nigeria Correspondence and requests for materials should be addressed to J. O. Sangodele (janetolayemi@binghamuni.edu.ng) Received 26 October 2016 / Received in revised form 29 November 2016 Accepted 20 December 2016 DOI 10.1007/s13530-017-0298-0 ©The Korean Society of Environmental Risk Assessment and Health Science and Springer 2017 pISSN : 2005-9752 / eISSN : 2233-7784 Toxicol. Environ. Health. Sci. Vol. 9(1), 12-22, 2017 Abstract Redox Status and Sperm Characteristics in 1,4- Dinitrobenzene-induced Reproductive Toxicity in Wistar Rats