Evaluation of the effect of glyphosate on glucose-6-phosphate dehydrogenase enzyme activity in vitro conditions

Purpose: The aim of this study was to investigate in vitro effect of glyphosate on Glucose 6-phosphate dehydrogenase (G6PD) enzyme activity. Materials and Methods: In terms of G6PD enzyme deficiency, samples taken from healthy and enzyme deficient male individuals were studied. After the hemolysates were prepared from blood sample, G6PD enyzme activities were determined by the modified Beutler method. Then, the effects of different concentrations (5.3x10-3, 5.3x10-4, 5.3x10-5, 5.3x10-6 mmol/mL) of glyphosate on G6PD activity were evaluated in normal and mutant enzymes. In addition, the in vitro effect of the antioxidant N-acetylcysteine (NAC) on the enzyme was investigated in the presence of glyphosate and without glyphosate. Results: While the result of normal erythrocyte G6PD activity was 12U/g for the individual, the result for the individual with enzyme deficiency was 2.5U/g Hb. The glyphosate’s maximum activity loss in the G6PD enzyme was observed in the 60th minute incubation. The highest inhibition was observed at 5.3x10-3 mmol/mL glyphosate. 4.7x10-7 mmol/mL N-Acetylcysteine partially increased the inhibition of glyphosate in the G6PD enzyme in healthy individuals, but had no effect on mutant G6PD. Conclusion: In humans, it is predicted that glyphosate affects G6PD enzyme activity in vitro and is an interference agent in the experimental process. In case of contamination, studies on limits of glyphosate that will not cause harmful effects in humans should be continued. Amaç: Bu çalışmada, substrat Glukoz-6-fosfat (G6P) ile moleküler yapı benzerliği ve enzimin kofaktör olarak Mg+2 kullanması nedeniyle, eritrosit G6PD enzimi üzerindeki in vitro etkisi incelendi. Gereç ve Yöntem: Çalışmada sağlıklı ve G6PD enzim eksikliği olan erkek bireylerin kan örneklerinden yararlanıldı. Hazırlanan hemolizatların enzim aktiviteleri modifiye Beutler yöntemi ile ölçüldükten sonra deney ortamına farklı derişimlerde (5.3x10-3, 5.3x10-4, 5.3x10-5, 5.3x10-6 mmol/mL) glifosat eklenerek aktivite üzerindeki etkisi değerlendirildi. Daha sonra antioksidan N-asetilsisteinin normal ve mutant enzimler üzerindeki etkisi in vitro deney koşullarında glifosatlı ve glifosatsız ortamda karşılaştırıldı. Bulgular: Sağlıklı örnekte eritrosit G6PD aktivitesi 12, enzim eksikliği bulunan olguda ise 2.5 U/gr Hb olarak saptandı. Deney ortamına glifosat eklenmesinden sonra en yüksek aktivite kaybı 60. dakikada saptandı. En yüksek inhibisyon oranı ise 5.3x10-3 mmol/mL glifosatın etkilediği çal