Reproductive inhibition with gossypol in the lesser bandicoot rat, Bandicota bengalensis

Abstract

Different concentrations of pure gossypol (PG), cottonseed extract containing 8.3% gossypol (CSE) and crude cotton seed oil containing 0.01% gossypol (CCSO) were fed to Bandicota bengalensis of both sexes to determine their effects on reproduction. Single oral administration of either 40 or 80mg PG/kg body weight (bw), or 100 or 200 mg CSE/kg bw did not affect reproductive parameters. Feeding of bait containing 0.05% PG for 4 days; 0.01 or 0.02% PG for 16 days and 0.2 or 0.5% CSE for 7 or 15 days each caused dose dependent decreases in weights of reproductive organs and accessory sex glands and motility, viability and density of sperm in cauda epididymal fluid. There was a dose dependent increase in sperm abnormalities. Gossypol-specific sperm abnormalities were also observed. No breeding was observed in untreated cyclic female rats paired with male rats treated with 0.05 or 0.02% PG for 4 or 16 days respectively, or 0.5% CSE for 15 days. A significant (p ≤ 0.05) increase in oestrous cycle length was observed in female rats fed bait containing 0.01% PG for 18 days or 0.5% CSE for 15 days. No effect on the oestrous cycle was observed in female rats fed bait containing 5 or 10% CCSO for 13 days. Feeding of bait containing 10% CCSO for 15 or 30 days to male rats also had no significant effect on reproductive parameters. Treatment of farmer’s sugarcane fields with 2% zinc phosphide followed by treatment with 10% CCSO for 15 or 30 days had no significant effect on rodent activity. Our results reveal that reproduction of B. bengalensis can be inhibited with multiple doses of gossypol but the effects are dose and time dependent.

Keywords

• cotton seed extract
• crude cotton seed oil
• gossypol
• reproductive inhibition