Induction of oxidative damage in the testes and spermatozoa and hematotoxicity in rats exposed to multiple doses of ethylene glycol monoethyl ether

Abstract

The effects of ethylene glycol monoethyl ether (EGEE) on the antioxidant systems of the testes and epididymal spermatozoa were investigated in rats at dose levels of 0, 100, 200 and 400 mg kg^-1 body weight (bw) administered orally by gavage for 14 consecutive days. The bw gain of the EGEE-treated rats decreased significantly at 200 and 400 mg kg^{- 1} bw compared with the control group. There were no significant changes in the weights of the testes, epididymis, seminal vesicles and prostate glands of the EGEE-treated rats. In the testes, while EGEE treatment resulted in significant decrease in glutathione (GSH) level, superoxide dismutase (SOD) and catalase (CAT) activities, it markedly increased the malondialdehyde (MDA) level, glutathione-S-transferase (GST) and lactate dehydrogenase (LDH) activities at 200 and 400 mg kg^-1 dose levels but vitamin C content remained unaffected in all the groups. In the spermatozoa, administration of EGEE caused significant decrease in the activities of CAT, GST and LDH as well as in the levels of vitamin C and GSH but significantly increased the MDA level and SOD activity compared with the control rats. Histopathological examination showed severe degeneration of the testes, such as generalized erosion and necrosis of the germinal epithelium of the testes, but mildly affected the epididymis at 400 mg kg^-1 dose only. Data on spermatozoa analysis of EGEE-treated rats revealed significant decrease in the epididymal spermatozoa number, testicular spermatozoa number, daily spermatozoa production and spermatozoa motility but significantly increased the total spermatozoa abnormalities without affecting the spermatozoa live-dead ratio at all dose levels when compared with the control group. Results of haematological examination showed that white blood cells (WBC), platelets neutrophils and mean corpuscular haemoglobin concentration (MCHC) were significantly lower whereas lymphocytes were increased in 200 and 400 mg/kg EGEE-exposed rats than in the controls. EGEE at 100 mg/kg bw produced minor effect on haematological parameters but adversely affected testes and spermatozoa. In summary, short term administration of EGEE is hematotoxic and gonadotoxic and its effects on male reproduction could be due to the induction of oxidative stress in testes and spermatozoa.