Toxicological impact of certain emulsifable concentrates of chlorpyrifos on male albino rats with regard to therapeutic role of selenium

ABSTRACT

The present study aimed to investigate the toxic effects of three trade names of chlorpyrifos [CPF] pesticide from different local manufactures; i.e. chlorozan [K], pestpan [W] and pyriban [H] on haematological indices, hepatic oxidative stress, in addition to lipid profile and thyroid hormone status in plasma of male albino rats. Also, to assess the therapeutic role of selenium [Se] under these conditions. Three compounds [K, W, and H] were administrated orally to rats at 23.43, 21.40 and 17.43 mg/kg b.w., respectively. [which represent the 1/4 LD50] with 5 doses per week for 28 days, and then these rats supplemented with Se at 50 micro g/day [RDA-US] as a therapeutic agent for 15 days. Additional group received Se [50 micro g/day] alone for the same time interval to assay whether Se has any biphasic effect. The results showed that CPF treatment [H], caused erythropenia, associated with decreasing of haemoglobin [Hb] concentration and packed cell volume [PCV] in rats. In contrast, the same treatment induced the leukocytosis and lymphocytosis. Also, Se-supplemented rats had leukocytosis and neutrophilia. However, supplemented rat with Se following treatment with CPF [H] improved the erythrogram, whereas leukopenia and lymphopenia occurred in rats received Se following treatment with CPF [K]. Chlorpyrifos treatments [K, W and H groups] did not alter markedly the hepatic lipid peroxidation [LPO] levels, while, the induction in the hepatic total glutathione [GSH] was occurred, compared with control group. The similar results were recorded in Se-supplemented rats. However, the fluctuation in the activity of alanine aminotransferase [ALT] was detected in chlorpyrifos-treated rats [W and H], whereas the aspartate aminotransferase [AST] activity did not change markedly. Supplementation rats with Se following treatment with CPF [K, W and H] reduced the levels of LPO, compared with CPF-treated rats [K, W and H]. This trend was more pronounced in Se- supplemented rats. In contrast, a significant enhancement in the activity of aminotransferases, i.e. ALT and AST was observed in rats supplemented with Se, after treatment with CPF [K and W]. Meanwhile, a marked inhibition in the activities of ALT and AST was detected in Se-supplemented rats. Overall, hypertriglyceridemia and hypercholesterolemia were observed in rats whether treated with CPF alone or pre-supplementation with Se and also in Se-supplemented rats. However, an elevation markedly in the thyroxine [T4] and triiodothyronine [T3] levels was found in CPF-treated rats [W and K, respectively]. While a marked decrease in the level of T3 was detected in rat supplemented with Se post-treatment with CPF [K and H] or alone. Moreover, the concentration of Se in hepatic tissues of rats received the Se following treatment with CPF was in order of W>H>K groups, whereas the Se element did not detected in liver tissues of Se-supplemented rats. Conclusion: Selenium supplementation to CPF-treated animals improved the haematological findings and hepatic lipid peroxidation level, in addition to lipidogram [i.e. HDL-C]