Effect of Mucuna urens (horse eye bean) on the gonads of male guinea-pigs.

The effect of Mucuna urens (seeds) on the gonads and sex accessory glands of male guinea-pigs was investigated. Sexually mature guinea-pigs of proven fertility were administered orally with 70 mg/kg and 140 mg/kg body weight of crude extract daily for 8 weeks respectively. Phytochemical screening of the seeds revealed the presence of alkaloids. No death or weight loss were observed during the duration of treatment. No pregnancy occurred in females mated with the treated males. Histological observations at high dose (140 mg/kg) showed complete degeneration of sperm in the testicular tubules. In some tubules, the acrosomal cap of the sperm cells was separated from the nuclei which underwent colour changes. In some tubules only the tails were left in the lumen. The spermatids, primary and secondary spermatocytes showed pycnosis while the morphology of spermatogonia and germinal epithelium appeared normal. Some epididymides were devoid of sperm while others contained degenerated spermatozoa and cell debris. In the prostate gland there was collapse of the villi and reduction of secretion in both the prostate and seminal vesicles. At low doses (70 mg/kg), there was spermatogenic arrest at spermatid stage. These observations have shown that M. urens is a potential male antifertility agent.