The Protective Effects of Quercetin on Paraquat-Induced Ovarian Toxicity in Female Wistar Rats

Paraquat is one of the chemical herbicides with high toxicity. In case of incorrect consumption, this chemical causes fatal poisoning in people, especially those active in the field of agriculture. Nowadays, using compounds of natural origin to improve or reduce the harmful effects of agricultural pesticides is one of the important issues that has attracted the attention of researchers in this field. Quercetin as a natural flavonoid is found in large quantities in fruits and vegetables. As a kind of natural antioxidant, this compound has great power in removing free radicals. The purpose of this research was to evaluate the protective effects of quercetin on ovarian toxicity caused by paraquat in rats.

To conduct this experimental research, 30 adult Wistar rats with an average age of 6 to 8 months and a weight range of 160 to 180 gr were randomly divided into 5 experimental groups including 6 rats in each group. Paraquat (1.25 mg/kg, intraperitoneally) was injected into mice. Then quercetin was injected intraperitoneally in concentrations of 50, 100, and 200 mg/kg. The negative control group received only normal saline. After 24 hours, the animals were sacrificed and their ovaries were evaluated for changes in oxidative stress indices.

The results showed that paraquat significantly increased the reactive oxygen species (ROS), protein carbonyl, and lipid peroxidation, and significantly decreased glutathione content and survival of ovarian tissue cells when compared with the control group (P<0.001). The results showed that different concentrations of quercetin could inhibit the lipid peroxidation reaction caused by paraquat toxicity, and the positive control group had a statistically significant difference compared to the negative control group (P<0.001). By administering quercetin in different concentrations, we saw a decrease in the production of lipid peroxidation. From a statistical point of view, quercetin at the concentration (mg/kg) of 50 had a significant difference with the positive control group (P<0.01) and this significant difference was also evident at the concentrations of (mg/kg) 100 and 200 (P<0.0001). Increasing the concentration of quercetin was associated with improved performance in inhibiting paraquat toxicity.

Results showed that quercetin can be useful as an effective antioxidant combination in improving oxidative stress indicators and ovarian tissue of mice. Quercetin can reduce paraquat-induced oxidative damage in rat ovarian tissues in a dose-dependent manner. Quercetin can potentially be used to control ovarian toxicity, modulate or inhibit oxidative factors, strengthen the immune system, and strengthen the antioxidant system in animal models. Probably, it can be used as a kind of safe supplement in combination with other drugs affecting the immune system. However, this hypothesis along with the effect of other drug interactions should be confirmed using appropriate in vivo studies. Understanding the process of cell death caused by paraquat and the inhibitory effect of natural antioxidants on it provides a new road map for future studies to develop new therapeutic strategies.