Hematotoxicity of Bacillus thuringiensis as Spore-crystal Strains Cry1Aa, Cry1Ab, Cry1Ac or Cry2Aa in Swiss Albino Mice

Abstract

al. Este é um artigo de acesso aberto distribuído sob os termos da Licença de Atribuição Creative Commons, que permite uso irrestrito, distribuição e reprodução em qualquer meio, desde que o autor e a fonte originais são creditados . Journal of Hematology & Thromboembolic DiseasesResearch Article Open Access AbstractFormulated and sporulated cultures of Bacillus thuringiensis (Bt) have been widely used against insect pests, but after the advent of genetically modified plants expressing δ-endotoxins, the bioavailability of Cry proteins has been increased. For biosafety reasons their adverse effects should be studied, mainly for non-target organisms. Thus, we evaluated, in Swiss albino mice, the hematotoxicity and genotoxicity of four Bt spore-crystals genetically modified to express individually Cry1Aa, Cry1Ab, Cry1Ac or Cry2A, administered alone by gavage with a single dose of 27 mg/ Kg, 136 mg/Kg or 270 mg/Kg, 24 h, 72 h or 7 days before euthanasia. Binary combinations of these four spore-crystal proteins were also assayed at 270 mg/Kg with a single administration 24 h before euthanasia. Control mice received filtered water or cyclophosphamide at 27 mg/kg. For hematotoxicity evaluations, blood samples were drawn by cardiac puncture and processed in a multiple automated hematology analyzer; for genotoxicity analyses, micronucleus test was carried out in mice bone marrow cells. Spore-crystal administrations provoked selective hematotoxicity for the 3 exposure times, particularly for erythroid lineage. A significant reduction in bone marrow cell proliferation demonstrated cytotoxic but not genotoxic effects. These effects persisted for all exposure times, becoming more evident at 7 days. Similar results were observed for binary combinations at 24 h, suggesting that further studies are required to clarify the mechanism involved in the hematotoxicity found in mice, and to establish the toxicological risks to non-target organisms, especially mammals, before concluding that these microbiological control agents are safe for mammals.

Statement on a request from the European Commission related to an emergency measure notified by France under Article 34 of Regulation (EC) 1829/2003 to prohibit the cultivation of genetically modified maize MON 810

“…Neither the results reported by Mezzomo et al (2013) and Zhou et al (2014) nor the arguments put forward by France in the French Authorities' report reveal any new information that would invalidate the previous risk assessment conclusions and risk management recommendations made by the EFSA GMO Panel.…”

“…In the case of the remaining scientific publications (Campagne et al, 2013;Mezzomo et al, 2013;Zhou et al, 2014), EFSA has focused its assessment on those aspects that are relevant to maize MON 810. These publications are therefore not considered further here, except for HCB (2013), which formed a key part of the basis of the scientific argumentation put forward in the French Authorities' report.…”

“…- Mezzomo et al (2013): Mezzomo et al (2013) studied the potential haematotoxicity (by conventional haematology) and genotoxicity (by in vivo micronucleus test) of spores of four Bt-strains expressing Cry toxins in Swiss albino mice. These Bt-strains were genetically modified to express Cry1Aa, Cry1Ab, Cry1Ac or Cry2Aa.…”

The Seralini affair: degeneration of Science to Re-Science?

“…The most recent apparent occurrence took place at the same journal, FCT, which retracted Séralini et al [2]. Mezzomo et al [45] was retracted by the editors without explanation, but was quickly republished in another peer-reviewed journal [46]. This trend raises larger scientific questions, two of which were expressed aptly by Portier et al [23]: The republication of Séralini et al [2] as Séralini et al [3] firmly establishes the data presented therein as peerreviewed science that must be considered by scientists and regulators alike.…”

Genetically engineered (modified) crops (Bacillus thuringiensis crops) and the world controversy on their safety

“…Despite the expectation of less Cry1Ab protein digestion and more absorption of Cry1Ab protein into the circulatory system of the GI-impaired rats, there was no evidence of toxicological effects (changes in clinical blood parameters and histologic appearance of organs) in the treated rats. Mezzomo et al (2013) reported that Bt spore preparations containing various Cry proteins were found to cause hemato-toxocity in mice when administered by oral gavage. However, Koch et al (2015) mentioned that such a result could be due to spore components other than Cry proteins.…”