Irfan Altuntas

Diazinon is one of the most widely used organophosphate insecticides (OPI) in agriculture and public health programs. The aim of this study was to investigate how an OPI, diazinon, affects lipid peroxidation (LPO) and the antioxidant defense system in vitro. For this purpose, two experiments were carried out. In experiment 1, the effects of various concentrations of diazinon on LPO and the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) in erythrocytes were studied. Each diazinon concentration was incubated with a previously prepared erythrocyte samples at +4°C for 0, 60 and 180 min. After incubation, the malondialdehyde (MDA) levels and the activities of SOD, GSH-Px and CAT were determined. In experiment 2, in order to determine the direct effect of diazinon on the activities of SOD, GSH-Px and CAT, the erythrocytes were haemolysed and incubated with the various concentrations of diazinon at +4°C for 0, 60 and 180 min. In experiment 1, MDA levels and the activities of SOD and GSH-Px increased with increasing diazinon concentration and incubation period, but CAT activity remained unchanged. In experiment 2, SOD activity was significantly decreased, and GSH-Px activity was significantly increased. From these results, it can be concluded that in vitro administration of diazinon results in the induction of erythrocyte LPO and changes the activities of antioxidant enzymes, suggesting that reactive oxygen species may be involved in the toxic effects of diazinon.

The effects of organophosphate insecticide methidathion (MD) on lipid peroxidation and anti-oxidant enzymes and the ameliorating effects of a combination of vitamins E and C against MD toxicity were evaluated in rat erythrocytes. Experimental groups were: control group, MD-treated group (MD), and MD+vitamin E+vitamin Ctreated group (MD+Vit). MD and MD+Vit groups were treated orally with a single dose of 8 mg/kg MD body weight at 0 hour. Vitamins E and C were injected at doses of 150 mg/kg body weight, i.m. and 200 mg/kg body weight, i.p., respectively, 30 min after the treatment of MD in the MD+Vit group. Blood samples were taken 24 hours after the MD administration. The level of malondialdehyde (MDA), and the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) were studied in the erythrocytes. MDA level increased significantly in the MD group compared to the control group (P <0.05) and decreased significantly in the MD+Vit group compared to the MD group (P <0.05). The activities of SOD, GSH-Px, and CAT decreased in the MD group compared to the control group (P<0.05). Only GSH-Px activity increased in the MD+Vit group compared with the MD group. These results suggest that treating rats with MD increases LPO and decreases anti-oxidant enzyme activities in erythrocytes. Furthermore, single-dose treatment with a combination of vitamins E and C 30 min after the administration of MD can reduce LPO caused by MD.

Methidathion (MD) [O,O-dimethyl S-(2,3-dihydro-5-methoxy-2-oxo-1,3,4-thiadiazol-3-ylmethyl) phosphorodithioate] is one of the most widely used organophosphate insecticides (OPIs) in agriculture and public health programmes. We have, therefore, examined the in vivo and in vitro effects of MD on the serum activities of cholinesterase (ChE), enzymes concerning liver damage and lipid peroxidation (LPO; only in vivo), and have evaluated the ameliorating effects of a combination of vitamins E and C against MD toxicity. The in vivo experimental groups were: control group, MD-treated group (MD), and a group treated with MD plus vitamin E plus vitamin C (MD+Vit). The MD and MD+Vit groups were treated orally with a single dose of 8 mg MD/kg body weight at 0 h. Vitamin E and vitamin C were injected at doses of 150 mg/kg body weight i.m. and 200 mg/kg body weight i.p., respectively, 30 min after the treatment with MD in the MD+Vit group. Blood samples were taken 24 h after the MD administration. For in vitro study, venous blood samples were obtained from volunteers, and serum recovered. The activities of serum enzymes were determined in each sample and these served as 0 h values. Each sample was divided into four portions, each of which served as one of the experimental groups, as follows: control group, vitamin E plus vitamin C group (Vit), MD-treated group (MD) and MD plus vitamin E plus vitamin C group (MD+Vit). Vitamin E and vitamin C were added at doses of 7.5 and 10 µg/ml, respectively, into the Vit and MD+Vit groups. MD was added at doses of 0.4 mg/ml into the MD and MD+Vit groups. The activities of serum enzymes were determined in each sample at 24 h. The results of the in vivo experiment demonstrated that thiobarbituric acid reactive substances were increased in the MD group compared with the control group, and decreased in the MD+Vit group compared with MD group. ChE activity was decreased in both MD and MD+Vit groups compared with controls and increased in the MD+Vit group compared with the MD group. The activities of aspartate aminotransferase (AST), alkaline phosphatase (ALP), γ-glutamyltransferase (GGT) and lactate dehydrogenase (LDH) were increased in both the MD and MD+Vit groups compared with the control group. AST activity was decreased in MD+Vit group compared with the MD group. Alanine aminotransferase (ALT) activity was decreased in both the MD and MD+Vit groups compared with control group. The results of in vitro experiment showed that all enzyme activities remained unchanged in both the control and Vit groups compared with values at 0 h. The activities of ChE, ALT and LDH were decreased in both the MD and MD+Vit groups compared with 0 h values. There was no significant difference between the MD and MD+Vit groups. The activities of AST, ALP and GGT remained unchanged in all groups. From these results, it can be concluded that MD caused liver damage, and LPO may be one of the molecular mechanisms involved in MD-induced toxicity. Single-dose treatment with a combination of vitamins E and C after the administration of MD can reduce LPO caused by MD.

The effect of GM-CSF (granulocyte macrophage-colony stimulating factor) on tissue necrosis and ulceration induced with doxorubicin extravasation was studied. Adult Wistar-Albino rats (n=36) were used in the study. Doxorubicin (0.4mg/300 g) was applied subcutaneously to abdominal wall. In group I (n=18), half hours after doxorubicin injection, GM-CSF 6 microg/300 mg was applied subcutaneously to the same localization. In group II (n = 18) same amount of physiologic saline (0.5 ml) were given subcutaneously to the injection site (as vehicle control groups). Group II and I were examined for induration or ulceration on 7th and 21st day. After evaluating the lesions, the injection sites were excised. Hydroxyproline (5-HP) values of dry tissue samples were calculated and histopathologic examination was done. At day seven there were four and eight ulceration in groups I and II, while there were four and 14 ulceration in the second evaluation at day 21st (p<0.05). 5-HP values of the groups were as follows. 97.43+/-20.39 in group land 91.34+/-22.26 in group II. Although there was an increase in epithelization, eosinophil and lymphocyte infiltration and mast cell number in group I in histopathologic examinations only the increase in angiogenesis in group I was found to be statistically significant (p<0.05). It can be concluded that GM-CSF may have beneficial effect in the treatment of doxorubicin induced tissue necrosis.