Assessment on acute and multigenerational toxicity of 1,3-diphenylguanidine (DPG) on freshwater water fleas (Moina macrocopa): Developmental, reproductive and oxidative stress effects

Tire particles leach 1,3-diphenylguanidine (DPG) into aquatic environments, raising concern about the chemical, and ecological impact. This study investigated the acute and multigenerational chronic effects of DPG on freshwater water fleas ( Moina macrocopa ), focusing on toxicity, reproductive and growth implications, antioxidant responses and oxidative stress biomarkers. Acute exposure revealed dose-dependent mortality increase with a significant reduction in Chronic exposure to a sub-lethal concentration of 0.5 mg/L DPG across four generations (P0, F1, F2, and F3) demonstrated substantial declines in reproductive output and growth metrics, alongside increased reactive oxygen species (ROS)activity and suppressed antioxidant enzyme activities, including, superoxide dismutase (SOD), catalase (CAT). Glutathione levels (GSH and GSSG) were reduced, with elevated GSH/GSSG ratios suggesting disrupted redox homeostasis. Pearson correlation analysis highlighted significant relationships between DPG presence and physiological and biochemical parameters, indicating a potential cascade of adverse effects stemming from oxidative stress. These findings underscore the ecological risk of DPG exposure, warranting further investigation into its toxicological pathways to protect aquatic ecosystems. • DPG, a common tire additive, harms water fleas across generations, impacting their growth, reproduction, and survival. • DPG exposure triggers oxidative stress in water fleas, disrupting their ability to combat harmful molecules. • DPG weakens the water flea's natural defense against oxidative damage, potentially leading to long-term health problems. • This research highlights the need for sustainable tire manufacturing practices that minimize the environmental impact of DPG and similar chemicals.