Vol.:(0123456789) Environmental Science and Pollution Research https://doi.org/10.1007/s11356-024-35195-5 RESEARCH ARTICLE Lysosomal disruption, mitochondrial impairment, histopathological and oxidative stress in rat's nervous system after exposure to a neonicotinoid (imidacloprid) Sarra Zouaoui 1,2  · Rachid Rouabhi 1,2 Received: 30 August 2024 / Accepted: 26 September 2024 © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024 Abstract Imidacloprid (IMI), a neonicotinoid pesticide, has been widely used due to its high efficiency against insect pests. However, its prolonged exposure may pose significant risks to non-target organisms, including mammals. Recent studies have raised concerns about its potential neurotoxicity, yet the underlying mechanisms remain poorly understood. This study aimed to assess the neurotoxic effects of chronic Imidacloprid exposure in Wistar rats, focusing on oxidative stress, mitochondrial dysfunction, and lysosomal disruption. Wistar rats were orally administered two doses of Imidacloprid (5 mg/kg and 50 mg/ kg body weight) for three months. Neurotoxic effects were assessed by measuring key biochemical markers such as the enzy- matic activities of catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD), and glutathione S-transferase (GST). Non-enzymatic markers, including glutathione (GSH) levels and malondialdehyde (MDA) index, were also evalu- ated. Mitochondrial function was assessed by analyzing oxygen consumption, swelling, and membrane permeability and histopathological changes. Lysosomal stability was examined using the Neutral Red Retention Time (NRRT) assay. Neutral red is a dye that accumulates in the acidic environment of lysosomes. Healthy lysosomes retain the dye, while compromised lysosomes lose it, indicating destabilization. By measuring the amount of neutral red retained in lysosomes, the NRRT assay assesses lysosomal integrity. Lysosomal pH variations were also monitored to evaluate functional changes. Microscopic analysis provided insight into structural changes in lysosomes and other cell components. Lysosomal destabilization was further confirmed by morphological alterations observed through light microscopy, revealing a progressive, time-dependent Responsible Editor: Lotfi Aleya Highlights • Imidacloprid exposure causes oxidative stress, mitochondrial impairment, and lysosomal destabilization in Wistar rats' central nervous system. • Decreased antioxidant enzyme activity (CAT, GPx, and SOD) was observed, along with increased GST activity and elevated MDA levels. • Mitochondrial dysfunction was evident, with alterations in oxygen consumption, swelling, and membrane permeability. • Lysosomal destabilization was confirmed by Neutral Red Retention Time assay and Histological Tests further supported by structural alterations observed under microscopy. • Lysosomal pH elevation indicated significant disruption in lysosomal function following Imidacloprid exposure. • Clinical signs of intoxication-included lethargy, decreased activity levels, impaired motor coordination, and behavioral changes such as reduced exploratory behavior and altered grooming patterns. • The study highlights the neurotoxic potential of chronic Imidacloprid exposure and its impact on cellular functions in the nervous system. Extended author information available on the last page of the article Content courtesy of Springer Nature, terms of use apply. Rights reserved.