GLYPHOSATE-RESISTANT TRANSGENIC ROUNDUP READY® SOYBEAN (GTS-40-3-2) DIET EFFECT IN WISTAR RATS

MOLINA, PATRICIA G.; BINOTTI, SILVANA; FARIAS, MARCOS E.; NIEBYLSKI, ANA M.

Encuentro; XXXVII Scientific Meeting of the Cuyo Biology Society; 2019

During the last two decades, the advent of genetically modified organisms (GMOs) has revolutionized agronomic practices. In Argentina, soybean is the main genetically modified (GM) crop being over the 90% of the Roundup Ready® (RR) variety, resistant to glyphosate, which is the main herbicide used. Due to the concern about the safety of meals containing GMOs, several studies have been made, although there is no consensus among scientists about GMOs safety. In this work, Wistar rats were divided in two groups: one was fed with a diet containing 13% RR transgenic soybean (RR group) and the other group with a similar diet containing non transgenic soybean (NO RR group) for 170 days, in order to evaluate different physiological parameters. Daily body weight gain (DWG) was measured. At the end of experimental time, liver was removed and blood was collected. After centrifugation, plasma and erythrocytes were separated. Osmotic Erythrocytes resistance was determined and then membranes and cytosol from erythrocytes were separated by centrifugation. Malonildialdehyde (MDA) and carbonyls (CAR) were determined in membranes. In plasma, bilirubin (BIL), GOT, GPT, total proteins (TP) and creatinine (CRE) were determined. Hepatic MDA and superoxide dismutase (SOD) were measured. While DWG was higher in NO RR group (1.6±0.05 vs. 1.37±0.05 g/day, p≤0.007), no changes were observed in TP levels. An increment in hepatic MDA (115±6.45 vs. 79.8±6 nmol/g tissue, p≤0.0017) and SOD (6.9±1.57 vs. 2.75±0.68 U SOD/mg protein, p≤0.032) levels was observed in RR group, which could indicate an oxidative stress process in this tissue, although no difference was observed in GOT and GPT levels. On the other hand, while erythrocytes showed decreased resistance in RR group (21.5±2.64 vs. 14.86±1.73 percent of hemolysis, p≤0.05), which could be due to a modification in the cell membrane, no difference was observed in plasmatic BIL or in MDA, and CAR levels in erythrocyte membrane. This would indicate that the change observed in the membrane resistance is not caused by oxidation. On the other hand, CRE levels did not show difference between both groups. According to the results, while some changes were observed in physiological parameters, some of them did not show difference between animals fed with RR or NO RR soybean. This indicates that RR soybean chronic intake could have any harmful effect, some studies should be carried out in order to clarify the effects observed, and long term studies should be performed.