Evaluation of Hematopoietic and Immune Toxicity in First-Generation (G1) Rats Following Maternal Thiacloprid Exposure During Gestation and Lactation, and the Protective Potential of Bitter Apricot Kernel Extract

Background: Thiacloprid, a neonicotinoid insecticide, is known to accumulate in various fruits and vegetables, including fresh tomatoes. There is escalating concern about the potential health risks associated with its exposure, particularly during vulnerable periods such as gestation and lactation. While previous studies have indicated adverse effects of neonicotinoids on diverse physiological systems, information on their impact on the hematopoietic and immune systems at low doses remains limited. Aims: The aim of this study was to evaluate the toxicity of thiacloprid at a microdose of 0.02 mg/kg and to assess the preventive effects of the hydroalcoholic extract derived from bitter almond apricot kernels (at a dose of 50 mg/kg) on the hematopoietic and immune systems during gestation (approximately 19 to 21 days) and lactation (approximately 3 to 4 weeks) in male and female Generation 1 (G1) rats. Methods: The investigation employed several methodological approaches to examine the effects of thiacloprid and the putative protective potential of the extract. Hematological and immunological parameters were evaluated using automated systems and specialized kits. Rats were systematically allocated into distinct experimental groups, including those exposed to thiacloprid and those concurrently treated with the apricot kernel extract, to observe the impacts on blood and immune parameters. Furthermore, histological analyses of the thymic tissue were performed to assess structural alterations induced by thiacloprid exposure and to ascertain the potential protective effects of the extract. Results: The results revealed a significant reduction in erythrocyte count, hematocrit, hemoglobin (HGB), and fibrinogen concentrations in rats exposed to thiacloprid. Conversely, a significant increase was observed in total white blood cell count, lymphocyte count, platelet count, mean corpuscular volume (MCV), reticulocyte levels, prothrombin time (PT), and activated partial thromboplastin time (aPTT). However, treatment with the apricot kernel extract led to notable amelioration of these perturbed parameters across the treated groups, indicative of a protective effect. Histological examination of thymic tissue from thiacloprid-exposed rats demonstrated severe histopathological damage, characterized by profound destruction of the thymic parenchyma, multifocal necrotic lesions, and the presence of numerous apoptotic bodies. In contrast, the thymic architecture remained intact in the extract-treated groups, with no significant histological abnormalities, thereby further corroborating the protective potential of the apricot kernel extract. Conclusions: Exposure to thiacloprid, even at a microdose, can induce discernible toxicity within the hematopoietic and immune systems during critical development stages. Nevertheless, the hydroalcoholic extract of bitter almond from apricot kernels appears to safeguard the cellular integrity of blood and its parameters against the toxic effects of this insecticide, likely attributable to its beneficial phytochemical constituents. Keywords: Thiacloprid toxicity; Bitter apricot kernel extract; Hematopoietic and Immune systems; Gestation and Lactation; Thymus histology.