Imidacloprid (IMI) is a widely used in Tunisia and abroad, and high doses of IMI have been known to cause endocrine disruption. Some reports claim that Urtica urens L. (UU) can reduce toxicity thanks to it anti-inflammatory and antioxidant activities, but there is no scientific evidence justifying its use, which lets us think to its direct effect on the metabolism of the ovarian tissue. The present study was undertaken to evaluate the protective effect of UU against the toxicity of Confidor®, whose active substance is imidacloprid (IMI), in female rat, as well as the chemical compositions of UU ethanol (EtOH) extract by GC–MS. Female rats were divided into control group, 3 groups treated with IMI at 50, 200 or 300mg/kg/day and three groups co-treated with IMI (50, 200 or 300mg/kg/day)+100mg/kg/day of UU, for 60days. Blood samples were collected for the dosage of 17β-estradiol levels. Ovaries were removed for tissular dosage of malondialdehyde (MDA), advanced oxidation protein products (AOPP), glutathione (GSH), vitamin E, catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx). Histological and histomorphometric examinations were performed as well.

IMI caused an acute ovary injury, increased the ovary tissue levels of MDA and AOPP, and decreased the levels of GSH, vitamin E, and antioxidant enzyme activities. The number and the diameter of follicles were markedly diminished together with a reduction of the relative weight of ovaries. Compared with controls, the treated rats exhibited a significant reduction in serum 17b-estradiol levels. These results suggest an endocrine disruption by IMI which may interfere with ovarian follicles development in rat. The injection of UU EtOH extract improved the histological and all biochemical parameters cited above.

In conclusion, IMI induced an acute ovary injury accompanied with disturbance of oxidant status and causes follicular atresia. Significant antioxidant activities were also observed in UU EtOH and a total of 31 compounds were identified. The injection of UU EtOH provided a significant protection which might be due to its antioxidant activities.