Dr. Mezzomo and his team from the Department of Genetics and Morphology at the Institute of Biological Sciences, University of Brasilia recently performed and published a study done involving testing Bacillus thuringensis toxin (Bt toxin) on Swiss albino mice. This toxin is the same one built into Monsanto’s GMO Bt crops such as corn and soy as a biopesticide.
…advances in genetic engineering promise the expression of multiple Cry toxins in Bt-plants, known as gene pyramiding. Therefore, studies on non-target species are requirements of international protocols to verify the adverse effects of these toxins, ensuring human and environmental biosafety.
Due to its growing use in agricultural activities, Bt presence has already been detected in different environmental compartments such as soil and water. Consequently, the bioavailability of Cry proteins has increased, and for biosafety reasons their adverse effects might be studied, mainly for non-target organisms. Studies are therefore needed to evaluate Bt toxicity to non-target organisms; the persistence of Bt toxin and its stability in aquatic environments; and the risks to humans and animals exposed to potentially toxic levels of Bt through their diet.
Thus, we aimed to evaluate, in Swiss albino mice, the hematotoxicity and genotoxicity of four Bt spore-crystals…
The scientists already knew that Bt toxin was very toxic and potentially deadly at levels above 270 milligrams per kilogram (basically ppm), so they instead tested levels ranging from 27mg/kg, 136mg/kg, and 270mg/kg for one to seven days (each of the Cry toxins were separated out and tested individually to maximize accuracy and total info). It was quite clear right off the bat that these Cry toxins were quite hemotoxic even at the lowest level of 27mg/kg administered only one time and one day as they clearly had damaged the blood, particularly in reference to red blood cells. The quantity and size of the erythrocytes (RBCs) were both significantly reduced, as was the overall levels of hemoglobin for which oxygen to attach to.
The tests clearly demonstrated that Cry proteins were cytotoxic to bone marrow cells, accounting for a portion of the measured effects. It should also be noted that a previous study found that these proteins caused hemolysis (they killed blood cells) in vitro, particularly seeming to target the cell membranes of red blood cells.
Cry1Ab (the protein produced in common Bt corn and soy) induced microcytic hypochromic anemia in mice, even at the lowest tested dose of 27 mg/Kg, and this toxin has been detected in blood of non-pregnant women, pregnant women and their fetuses in Canada, supposedly exposed through diet . These data, as well as increased bioavailability of these MCA in the environment, reinforce the need for more research, especially given that little is known about spore crystals’ adverse effects on non-target species.
While Bt toxin is not known to bioaccumulate in fat cells and internal organs, it is of note that the study demonstrated clearly that there was a significant increase in measurable negative effects of the toxin as time progressed especially concerning the higher doses. Also of note was the increased inflammatory response, while it was quite minor, the scientists consider it to be statistically significant due to the intricacies of their chosen test subjects’ biology. No measurable genotoxicity was found.
The full results of the study and a more detailed explanation can be found at, along with full citations for this article: http://gmoevidence.com/wp-content/uploads/2013/05/JHTD-1-104.pdf
Additional GMO research: Health Guide: GMO Research