Coconut water (CW) contains cysteine, an amino acid which influences glutathione metabolism and promotes reproductive functions. The effects of CW and N-acetyl cysteine (NAC) were compared on the hypothalamo-pituitary-gonadal-axis of danazol-(a GnRH antagonist)-treated rats. Seven groups of male rats were treated orally for six weeks as follows; 1: 20 mL/kg distilled water (Control); 2: 20 mL/kg Corn oil; 3: 20 mL/kg CW; 4: 100 mg/kg NAC; 5: 200 mg/kg Danazol; 6: Danazol+CW; 7: Danazol+NAC. Serum gonadotropins and testosterone; sperm indices; testicular malondialdehyde and glutathione were determined. Sperm quality increased in groups 3, 4, 6 and 7, and reduced in group 5 compared with groups 1 and 2. Gonadotropins and testosterone increased in groups 6 and 7 compared with group 5. Malondialdehyde reduced, while glutathione increased, in groups 3 and 4 compared with group 1. These similarities suggest that cysteine contributes to the effects of coconut water along the hypothalamo-pituitary-gonadal-axis.
