[In vivo scavenging effect of ethylcysteine on reactive oxygen species in human semen].

PURPOSE The production of reactive oxygen species (ROS) is a normal physiological event in various organs including the testis. Overproduction of ROS, however, can be detrimental to sperm, being associated with male infertility. In vivo experiments using vitamin E (Vit. E), one of the major membrane protectants against ROS and lipid peroxidation, have shown its significant potential in treating ROS-associated male infertility. There has been no study that the scavenging drugs reduce the level of ROS in human semen. Previously we reported the in vitro scavenging effectiveness of ethylcysteine (EC) against ROS in human semen. The present study was performed in order to determine the effectiveness of the in vivo administration of EC as treatment for ROS-associated male infertility. PATIENTS AND METHODS Ten cases of male infertility, with the exceptions of azoospermia and pyospermia, were chosen. Patients were divided randomly into two groups. Each group received either 600 mg/day of EC (Group A) or Vit. E 600 mg/day (Group B) for 3 months. Then, after a 1-month wash-out period, the patients were switched to another treatment. Conventional semen analysis, computerized motility assessment, measurement of ROS generation and sperm function assessment by triple stain were performed before and after administration of EC and Vit. E. The levels of EC and Vit. E were also assessed in patients' blood serum and seminal plasma before and after administration of EC and Vit. E. RESULTS Sperm density and sperm motility did not improve but sperm function had a significant tendency toward improvement after administration of EC and Vit. E. ROS levels significantly decreased only after administration of EC After administration of EC and Vit. E, their levels significantly increased in patients' blood serum but were unchanged in patients' seminal plasma. CONCLUSION Since our study showed that oral administration of EC produced results similar to those of Vit. E, we conclude that EC is an effective treatment agent for ROS-associated male infertility.