The present study aimed to investigate the toxic effects of environmentally relevant concentrations of esfenvalerate on non-target organisms and the potential toxicity-reducing role of Taraxacum officinale extract (Toex). Esfenvalerate concentration measured as 0.8 ��g L in Pazarsuyu stream, which is also used in agricultural irrigation in Giresun-Bulancak region, was used as environmentally relevant concentration. 0.8 ��g L esfenvalerate resulted in a reduction in the mitotic index, levels of chlorophyll a and b, as well as root elongation, germination and weight gain in the bioindicator organism Allium cepa. Esfenvalerate treatment resulted in an increase in the frequency of chromosomal abnormalities, as well as the induction of O formation and oxidative stress, which was evidenced by an elevation in the levels of proline and malondialdehyde. Following treatment with 0.8 ��g L esfenvalerate, the percentage of tail DNA was 83.6%, with a concomitant increase in cell death of 77.4% in comparison to the control. In addition to determining the toxic effects of insecticides on non-target organisms, the solutions to be developed against these toxic effects are also very valuable. For this purpose, the protective properties of Toex were tested against the toxicity induced by esfenvalerate. The application of 7 mg L Toex together with esfenvalerate provided 48.88% protection in germination percentage, 28.61% protection in cell proliferation, 37.14% protection in sticky chromosome, and 58.7% protection in cell death. In conclusion, the use of insecticides has been demonstrated to have adverse effects on non-target organisms. Comprehensive toxicity testing represents a valuable resource for the effective management of insecticide risks. Furthermore, the investigation and identification of solutions to problems enhances the value of the effort expended. In this study, Toex provided high protection against esfenvalerate, which has been shown to induce oxidative stress and other toxic effects.
