Seminal plasma zinc level in users of gossypol

Seminal plasma zinc levels were determined in 13 healthy male volunteers on gossypol, a triterpenoid aldehyde extracted to purity from cotton plant which has been found to be an orally active male fertility regulation agent that is simple, economical and reversible. Each subject was given 20 mg gossypol tablet daily until azoospermia occurred. Thereafter, a maintenance dose of 7.5 mg or 10 mg of gossypol was given orally to alternate subject. Each subject was followed up monthly for one year. Serial semen analysis and seminal plasma zinc levels were determined prior to and after administration of gossypol monthly for 52 weeks. The mean sperm count and motility decreased significantly until azoopermia occurred in all subjects at about the 20th week of follow up. However, there was no significant difference in the mean seminal plasma zinc levels throughout the period of observation irrespective of the dosage regimen of gossypol used by the subjects. It was concluded that gossypol has no effect on the seminal plasma zinc level in users of gossypol.