Dietary grape seed extract mitigated growth retardation, hormonal delay, and gastrointestinal toxicity induced by insecticide imidacloprid in Nile tilapia

Overusing the insecticide imidacloprid (IMD) in agriculture has led to its presence in water bodies, causing serious environmental issues and fish toxicity. This study explored the potential benefits of grape seed extract (GSE) in mitigating IMD-induced growth and hormonal and gastrointestinal toxicity in Nile tilapia. A total of 240 healthy juvenile tilapias Oreochromis niloticus (O. niloticus), weighing an average of 11.44 ± 2.01 g at 2 weeks of age, were divided equally into four groups, each with three replicates. The control group received no special treatment, while the second group was given a diet containing 2% GSE^®. The third group was exposed to 1.5 µg IMD per liter of water. The fourth group was subjected to the same IMD exposure and fed a diet containing 2% GSE^®. These treatments were administered continuously for 75 days. Growth indices, survival rate, biochemical parameters, and digestive enzymes were measured. In addition, the growth-related hormones, intestinal malondialdehyde (MDA), and catalase (CAT) were evaluated. Histological evaluations were conducted on the stomach, duodenum, ileum, and hepatopancreas, alongside body composition analysis. Exposure to IMD delayed growth, impaired serum biochemistry and digestive enzyme activity, altered body composition, obstructed hormonal responses, decreased CAT activity, and increased intestinal MDA. All tissues exhibited signs of degradation. Combining dietary GSE^® with IMD improved the former parameters affected by IMD. In conclusion, research suggests that incorporating GSE^® into the diet may help reduce the adverse effects of IMD exposure on Nile tilapia, presenting a promising opportunity to address the environmental impacts of insecticide contamination in aquatic ecosystems.