Akademik Veri Yönetim Sistemi
MEETCON - GLOBAL SCIENTIFIC RESEARCH CONGRESS, Tbilisi, Gürcistan, 26 - 31 Ekim 2025, cilt.1, ss.179-186, (Tam Metin Bildiri)
Spinosad is an insecticide obtained through natural fermentation from the bacterium Saccharopolyspora spinosa. It is used as an insecticide in agricultural activities. Its mechanism of action is to target nicotinic acetylcholine receptors in the insect nervous system, causing hyperactivity and paralysis. Freshwater mussels (Unio delicatus) are filter-feeding organisms living in aquatic ecosystems and are considered model organisms for bioassays. The transport of pesticides used for various purposes into aquatic systems through flooding, erosion, wind, and other processes can elicit physiological and biochemical responses in non-target species such as freshwater mussels. One of these effects is oxidative stress. In this study, oxidative stress parameters were investigated in freshwater mussels exposed to an acute sublethal dose of spinosad. In the study, freshwater mussels (n=100) were procured from local fishermen in Bursa Province (Türkiye) and brought to the laboratory alive in aerated tanks. The lethal dose (LC50=85.1 mg/L) was determined. The experimental system was set up in duplicate, with 10 mussels per aquarium, comprising a control, a vehicle control, and a dose group. Freshwater mussels were exposed to a sub-lethal dose of 8.51 mg/L spinosad for 96 hours. At the end of the experiment, the mussels were dissected under ice anesthesia, and the digestive glands and gills were excluded. All tissues were stored at -80ᵒC until the day of the experiment.
In this study, oxidative stress indicators, such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione (GSH), and malondialdehyde (MDA), were analyzed in the digestive gland and gill tissues of mussels. Analyses were performed using commercial enzymatic assay kits (Otto Scientific) according to the manufacturer's protocols.
The level of SOD increased approximately fourfold in all tissues in both the vehicle control group and the dose group compared to the control group (p<0.05). CAT levels, decreased approximately fourfold in all tissues compared to the control group (p<0.05). GPx levels, increased slightly in both tissues compared to the control group; however, this increase was not statistically significant (p > 0.05). GSH levels, did not show a statistically significant change compared to the control group (p>0.05). Similarly, MDA levels also, did not show a statistically significant change in the digestive gland compared to the control group (p>0.05), but decreased significantly in the gill tissue (p<0.05). In our study, some findings are similar to, and some contradict, studies on oxidative damage caused by spinosad in aquatic organisms in the literature. Future studies examining longer exposure times and different dose ranges will contribute to a more comprehensive assessment of the ecotoxicological risk of spinosad.
This study was supported by Gazi University Scientific Research Projects (Project ID: FCD-2024-8851). We would like to thank the Gazi University Scientific Research Projects Unit for their kind support.