Interactive effects of imidacloprid, profenofos and carbosulfan at low concentrations on homeostasis and haematological indices in male albino rats

Toxicity data with single pesticides to test animals are far more abundant than with mixtures [Flipo et al., 1992]. Consequently, these data cannot be used directly to predict the effect of pesticide combinations. Three pesticides; imidacloprid, profenofos and carbosulfan, administered to rats per OS at low level dose equal 1/30 LD50 for each insecticide, which represent 111, 70 and 43 ppm, respectively on homeostasis status and haematological indices [El-Kashory and El-Said, 2001], were selected to explore their combined action of subchronic exposure studies for 90 days in adult male albino rats. Homeostasis-related parameters such as; aldosterone [Ald.], sodium ions [Na+], potassium ions [K+], total chloride ions [T.Cl-] levels, pH value and haematological indices were examined in rats after an administration with different insecticide combinations. Moreover, after withdrawal the pesticide combinations for 30 days, as a recovery period, the above mentioned parameters were evaluated, in comparison with the control group. Results showed that, pesticide combination imidacloprid/profenofos [I + P] induced significant decrease in Na+ and T.Cl- ions levels and significant increase in pH value. While, it did not alter both Ald. and K+ ions levels. Combination imidacloprid/carbosulfan [I + C] increased significantly Ald., T.Cl- ions levels and pH values. On the contrary, it reduced Na+ and K+ ions levels significantly. Combination of profenofos/carbosulfan [P + C] decreased Ald. and Na+ significantly, while, K+ and T.Cl- level and pH value did not alter. In addition, tri-combination imidacloprid/ profenofos/carbosulfan [I + P + C] increased Na+ and T.Cl- ions level and pH value; while, a marked decline in Na+ ions level was occurred, as well as, no appreciable changes in K+ ion levels were observed. The combinations of I + P and I + C caused erythropenia [reduced RBC mass] associated with a significant decrease in PCV in I + C-treated rats. While, di-combinations P + C, I + P and I + P + C tri-combinations increased markedly of PCV and MCV. However, leukocytosis [elevated WBCS count] was observed in I + P + C-treated rats. After the pesticides combination withdrawal, changes in some parameters returned to the normal values, in comparison with the control group; while, the others still altered. Moreover, some parameters did not exhibit any changes unless after the stop of the treatment. In conclusion, this study supports the notion that; an interactions effects of pesticide combinations may be consider as contributor factor enhance their side effects

Lambda-cyhalothrin and deltamethrin evoke lipid peroxidation and induce oxidative stress in neonatal rats

Neonates are known to be more vulnerable than adults, and their susceptibility to the side effect of pesticides attracted more concern in recent years. This work was carried out to assess the sensitivity of pups to the alpha-cyano synthetic pyrethroid insecticides lambda-cyhalothrin and deltamethrin. LD[50] was used as indicator of acute toxicity. Moreover, lambda-cyhalothrin and deltamethrin at low doses [0.31 and 0.36 mg/kg bw., respectively], were given daily in corn oil throughout the lactation period. Groups of pups [5 as control + 5 from each insecticide treatment group] were with drawl and sacrificed after 4, 10 16 and 21 days, and the level of malondialdehyde [MDA] which expresses the lipid peroxidation status was estimated in the tissues of the liver and brain. At the same time, superoxide dismutase [SOD], glutathione-S-transfersase [GST] activity and reduced glutathione [GSH] level were determined in both brain and liver. Glutathione reductase [GR] and glucose-6-phosphate dehydrogenase [G6PDH] activity were estimated to evaluate the redox cycle State. Results indicated that both insecticides significantly increased lipid peroxidation and decreased the [SOD], [GR] and [G6PDH] activity and [GSH] level in liver. The effect of both pyrethroids on these parameters in brain tissue was less than that in the liver. Conclusively the results obtained suggested that both synthetic pyrethroid insecticides were able to produce oxidative stress and alter the antioxidant defense mechanisms. Furthermore, the neonates [i.e. pups in lactation period] seem to be more susceptible to pyrethroids exposure than expected