Female reproductive toxicity induced by nitrate in drinking water and the comparative ameliorative effects of ascorbic acid, curcumin and their combination

The reproductive toxicity of nitrate in juvenile and adult female rats, and its amelioration with ascorbic acid, curcumin or their combination, was studied. Rats were classified into five groups: control, nitrate, nitrate + ascorbic acid, nitrate + curcumin, and nitrate + ascorbic acid + curcumin. Nitrate at 250 mg/L drinking water and ascorbic acid and curcumin at 100 mg/kg body weight were provided to rats via oral gavage for 42 days. Results showed a significant increase in malondialdehyde (MDA) level and decreases in activity of superoxide dismutase (SOD) and catalase (CAT); level of estrogen, progesterone, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in all treated groups of juvenile and adult rats, except for the group given a combination of both antioxidants. Glutathione peroxidase (GPx) activity decreased in the nitrate group of these rats. The number of atretic follicles increased and follicular diameter decreased in the nitrate group of juvenile and adult rats. A similar trend was also observed in juvenile rats given nitrate with ascorbic acid individually. In conclusion, nitrate caused higher toxicity in the ovaries of juveniles compared to adults. However, negative effects were reversed by amelioration with ascorbic acid and curcumin together, followed by curcumin and ascorbic acid separately.