How Does Bispyribac Sodium Affect Freshwater Organisms: An Investigation of Oxidative Stress and Apoptotic Biomarker Responses in Freshwater Mussels Unio delicatus ?

Herbicides are one of the commonly used pesticide groups throughout the world. Following application to agricultural areas, the chemicals are absorbed into the soil and therefore they contaminate groundwater and surface water. Bispyribac sodium, as a herbicide, is widely used in rice fields. However, limited knowledge has been reported on the effects on aquatic life. Therefore, the present study aimed to investigate the effects of bispyribac sodium on the biochemical parameters of freshwater mussels including oxidative stress and apoptotic biomarkers. The mussels were exposed to 5 and 10 μg/L of bispyribac sodium for 24 h and 7 days. According to the biochemical parameters, TOS and TAS levels of hemolymph significantly decreased at 24 h and 7 days, and malondialdehyde levels in digestive glands were significantly decreased at both exposure times (p < 0.05) while the glutathione and protein carbonyl levels in digestive glands increased after 7-day exposure. Significant increases in MDA levels were observed in gill tissues following bispyribac sodium exposure, particularly after 7 days, indicating pronounced lipid peroxidation. The caspase-1, caspase-3, caspase-8, and caspase-9 also altered in the exposed groups at 24 h or 7 days in the gills and digestive glands. The data in this study indicated that bispyribac sodium exposure affected the biochemical parameters of freshwater mussels.