Assessment of Anticholinesterase Toxicity, Oxidative Stress and Antioxidant Status in Carbamate and Organophosphorus PesticidesExposed Agricultural Workers

Abstract

Among the numerous pesticides, anticholinesterase compounds are widely used. Their toxicity induced by cholinesterase inhibition at the synapses and neuromuscular junctions, leading to neurological disorders. Inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) has been used as sensitive biomarkers for pesticides exposure. In the present study, AChE and BuChE levels were estimated in agricultural workers exposed to carbamate and organophosphorus pesticides with average 9.8±3.5 years relative to the controls. The toxic effects of pesticides may be attributed to induction of oxidative stress and alteration in antioxidant system. Our results showed significant decrease in AChE and BuChE levels with inhibition percentage of 39% and 61% respectively, in exposed workers than controls. Additionally, there was a significant increase in malondialdehyde (MDA) as an oxidative stress marker. Concerning antioxidant status, there was significant decrease in reduced glutathione (GSH) levels while there were significant increases in activity of glutathione dependent enzymes, glutathione peroxidase (GPx) and glutathione-S-transeferase (GST). On the other hands, there were significant decreases in enzymatic antioxidants, super oxide dismutase (SOD) and catalase. A negative correlation was found between BuChE activity and MDA levels. So, it was concluded that evaluation of BuChE inhibition may be sensitive tool for assessing the risk of oxidative stress induced after occupational pesticides exposure.

The Association between Serum Malondialdehyde and Nitric Oxide Level of Children Living In Area of Chronic Pesticide Exposure

“…The results of the study showed that the MDA outcomes of the working group were higher than the control group (6.51 (SB 1.95) vs 2.344 (SB 8.823) nmol/mL). 10 Unlike the studies mentioned above, the results of this study did not indicate any association between the level of serum MDA and NO in children living in areas of chronic pesticide exposure (p = 0.994).…”

Oxidative Stress Indices of Organophosphates Pesticides Among Agricultural Workers at Mit-Ghamr District, Egypt

“…Furthermore, Kisby et al study in USA reported that Serum MDA levels were 4.9 times and 24 times higher in farm workers and applicators, respectively, than in controls [24], also Vidyasagar et al results were in line with our results [25]. Moreover, our results are in consistent with a recent Egyptian study of Noshy et al which was conducted in El Monofya governorate, and reported an increased MDA levels in farm workers and pesticides applicators than the controls [26]. Moreover, other studies support these result [7] [9] [14] [27].…”

“…The present study revealed that SOD was significantly lower among exposed group compared to non-exposed group, (p-value = 0.000) (table 1), this is in agreement with Vidyasagar et al who reported that RBC SOD was lower among exposed versus control group [25]. Other studies in India and Egypt showed the same reduction in the SOD activity in the exposed groups [19][20][21][22][23][24][25][26]. In contrast to these results, some studies found an elevation of SOD levels in exposed group like Simoniello et al [30].…”

“…Regarding SOD and BuChE, it was found that both significantly decrease with increased work duration (years), number of worked hours /day and hours of spraying pesticides /day (table 2), and this agree with studies of Mostafalou and Abdollahi [33] and Surajudeen et al [9]. Moreover, Noshy et al found a negative correlation between the inhibition in BuChE activities and the period of exposure to pesticides (day/year) in exposed workers [26]. The inverse correlation indicates that the longer the duration of exposure to OPs, the lower the ChE activity and the more the risk of adverse effect of OPs.…”

“…Correlations coefficient between the three oxidative stress markers revealed that a strong negative correlation between the level of MDA and level of BuChE (r = -0.69) (p-value = 0.000), and positive correlation between the level of Superoxide Dismutase and Butyl Choline esterase enzyme (r = 0.56), (p-value = 0.000) (table 2), and these are in line with Surajudeen et al [9], Zepeda-Arce et al [5] and Noshy et al [26] as all found an inverse correlation between BuChE and MDA activities. This suggests that the more depressed serum AChE activity in OP exposed farm workers, the higher the MDA level and the higher the risk of oxidative damage due to oxidative stress.…”