Novel hydrogen-producing Si-based agent reduces oxidative stress, improves sperm motility and in vitro fertilization rate in varicocele.

BACKGROUND Varicocoele-induced male infertility potentially involves oxidative stress. Although varicocoelectomy is recommended for varicocoele patients presenting abnormal semen findings, no pharmacotherapeutic methods currently exist. We have recently developed a silicon-based agent that produces hydrogen by the reaction with water. OBJECTIVES This study aimed to investigate the therapeutic effects of oral administration of a Si-based agent on varicocoele rat. MATERIALS AND METHODS Twenty-one rats were divided into four groups: varicocoele + normal diet (n = 5), varicocoele + Si-based agent-supplemented diet (n = 6), sham + normal diet (n = 5), and sham + Si-based agent-supplemented diet (n = 5). All rats were euthanized four weeks after surgery. RESULTS The mean left epididymal sperm motility was 74.4% in the sham group, 72.3% in the sham + Si group, 57.6% in the varicocoele group, and 66.9% in the varicocoele + Si group. Epididymal sperm motility was significantly lower in the varicocoele group, but was significantly higher upon Si-based agent ingestion (P < .01). The mean left testicular weight, Johnsen's score, and left epididymal sperm concentration did not differ significantly between groups. The 8-OHdG concentration and DNA fragmentation rate were significantly increased in the varicocoele group, but were significantly decreased in the Si-based agent intake group (P < .01). Additionally, the IVF rate was significantly lower in the varicocoele group (26.3%) compared with the sham group (73.4%; P < .01), and was significantly higher in the varicocoele + Si group (51.8%) compared with the varicocoele group (P < .05), indicating that the Si-based agent improves IVF rates. DISCUSSION AND CONCLUSION Oral intake of the silicon-based agent improves epididymal sperm motility and in vitro fertilization rates through hydrogen production and subsequent reduction of oxidative stress. Considering the lack of effective noninvasive methods, this Si-based agent is potentially applicable for treating varicocoele-induced abnormal semen parameters.