Single dose effect of diazinon on biochemical parameters in testis tissue of adult rats and the protective effect of vitamin E

Diazinon [DZN] is an organophosphate pesticide that widely used for agricultural pest control all over the world. DZN affects target organs including reproductive system by inhibiting the activity of acetylcholinesterase and inducing oxidative stress. Vitamin E [alpha-tocopherol] is a strong antioxidant which inhibits free radicals, and probably can reduce lipid perxidation effectively in biological systems. The present study, aimed to evaluate the effects of DZN on malondialdehyde [MDA] and glutathione [GSH] levels in testis of rats and protective effect of vitamin E. In this experimental study, thirty adult male Wistar rats [200-250 gr] were divided into 5 groups [n= 6]: control group [did not receive any material], sham group [received only pure olive oil], experimental group 1 [DZN, 60 mg/kg], experimental group 2 [Vit E, 200 mg/kg] and experimental group 3 [DZN+Vit E, with the same dose]. All groups were sacrificed after 6 weeks and right testis was used to measure the MDA and GSH levels. The amount of MDA was determined by the thiobarbituric acid assay and 5, 5-Dithio-bis [2nitrobenzoic acid] DTNB-recycling protocol was used for GSH assay. The results showed that DZN increased MDA level [p<0.001] and reduced GSH level [p<0.001]. Administration of DZN plus vitamin E decreased the MDA level [p<0.001] and increased GSH level [p=0.001]. DZN induced lipid peroxidation in the testis of rats. Vitamin E by its antioxidant activity was able to improve the toxic effect of DZN

[Assessment of erythrocyte and serum cholinesterase activity in male rats treated with diazinon, and protective role of vitamin E]

Background: Diazinon [DZN] is an organophosphate [OP] that inhibit cholinesterase activity and induce oxidative stress in the target tissues such as the the reproductive system .The aim of present study was to evaluate the effects of diazinon on cholinesterase activity in blood serum and erythrocytes of male rats and to assess the protective role of vitamin E.

Material and Methods: In this experimental study, thirty adult male wistar rats [200 - 250 gr] were divided into 5 groups [n = 6]: control group [did not receive any material], sham group [received only pure olive oil], experimental group 1 [DZN, 60 mg/kg], experimental group 2 [received DZN+Vit E daily, with the same dose] and experimental group 3[Vit E 200 mg/kg]. DZN and solvent was injected intraperitoneally [IP] and vitamin E was administrated by gavage. After 6 weeks, 3 ml blood from the heart tissue was taken and titrimetric and Ellman's method respectively was used for serum and erythrocyte cholinesterases activity evaluation. Data were analyzed using SPSS software. P<0.05 value was taken as statistically significant.

Results: The results showed that diazinon, reduced activity of acetylcholinesterase [P= 0.000] and pseudocholinesterase [P=0.01] in experimental group 1 compared to the control group. Inhibition in erythrocyte and serum cholinesterase activity was not recovered in experimental group 2 [use of diazinon plus vitamin E diazinon].

Conclusion: According to inhibit the activity of two important enzymes of erythrocyte and serum cholinesterase in rats treated with diazinon, there are possibility of cytotoxicity at farmers and people who are in contact with these compounds. On the other hand, cholinesterase activity did not recovered by vitamin E probably due to the competitive nature of enzyme inhibition by diazinon. Therefore, care should be taken to prevent from entering toxin to the body.