دراسة الدور الوقائي لبعض المركبات النشطة بيولوجيا اتجاه الأثر السمي للمبيدات الهيدروكربونات على الجهاز العصبي و المناعي عند الجرذان

Abstract

Environmental toxicology is nowadays facing a great challenge especially as it is addressing to study the impact of toxic pollutants on the living organism of the general population, in contrast to professional pharmacology or toxicology which target limited groups in their professional and medical milieu with well-known diagnostic and therapeutic approaches. Indeed, many food biological matrixes are contaminated with pesticides, polycyclic aromatic hydrocarbons and heavy metals with very little concentrations that we consider such negligible daily doses but which could accumulate with the time because their solubility in different organs. This study focuses on the preventive effect of some bioactive compounds such as vitamin C, vitamin E, quercetin and phenolic extract from orange peel Citrus Senensis, against the toxic impact of a polycyclic aromatic hydrocarbon, the naphthalene and endosulfan, as organochlorine pesticide on brain and immune systems. The results showed a significant change in neuronal redox status in cytosol and brain mitochondria. Indeed, endosulfan and naphthalene administered alone or in mixture at the respective doses of 2mg / kg and 50 mg / kg, showed a disturbance in the balance prooxidant / antioxidant in cell compartmentalization since they caused a significant fall in the level of GSH, GST, SOD and CAT cytosolic rats treated with these chemicals. The results of these studies have also shown a significant increase in MDA cytosolic and a highly significant reduction of cytosolic proteins level was also recorded compared to the control group. Furthermore, the results of this work have showed a very significant decrease in mitochondrial enzymatic activity of SOD and CAT parallel to fall of GSH rate. Increased peroxidation was recorded via the significant increase in mitochondrial MDA following animal exposure to endosulfan alone at a dose of 2 mg / kg, reflecting a loss of integrity mitochondrial membranes. Conversely, the administration of quercetin (10 mg / kg) associated with endosulfan (2mg / kg) was able to prevent this neuro-mitochondrial toxicity in rats. The in vitro study of the mitochondrial integrity showed, in the presence of increasing concentrations of endosulfan, a decrease in absorbance of mitochondrial suspensions, demonstrating that mitochondria were received massive internalization of water via the opening giant mitochondrial pores (MPTP), causing them to swell. Inversely, the tubes containing endosulfan and quercetin showed similar absorbance to the control tube, which provides information on the maintenance of intact mitochondrial integrity which not allowed undergoing this swelling. This study also showed a toxic effect on the immune and blood systems through a very significant increase in the overall number of lymphocytic cells in rats of groups treated with the mixture endosulfan and naphthalene. It was also found that in the same study, a significant and very significant respective reduction in granulocytes and monocytes rates. The evaluation of some blood biochemical parameters did appear impairment of liver function, kidney and pancreas via the significant increase in transaminases enzymes in the blood serum (TGO and TGP), cholesterol, triglycerides, urea, creatinin and blood glucose compared to the control group. Meanwhile, bioactive substances used in these studies, warned the occurrence of these disturbances in the function of these organs in animals exposed to these persistent organic products. In conclusion, the results of this present study showed that endosulfan and naphthalene have neurotoxic power and immunomodulator effect in environmental doses which have been administered individually or associated in rats. Moreover, it appears that these persistent organic products significantly alter liver and kidney function.