Science in Society Archive

Bt Toxin Kills Human Kidney Cells

Cry1Ab biopesticide kills human cells at low doses as does Roundup herbicide Dr Eva Sirinathsinghji

A new study shows that low doses of Bt biopesticide CryA1b as well as the glyphosate herbicide, Roundup, kill human kidney cells. The Bt biopesticide conferring insect resistance and the glyphosate tolerance trait tied to the use of glyphosate herbicides account for almost all the GM crops grown worldwide. Bt crops already constitute 39 % of globally cultivated genetically modified (GM) crops, yet this is the first study that provides evidence on the toxicity of Bt protein in human cells.

This work comes at a time when the French environment and agricultural ministers are seeking an EU-wide ban of Monsanto’s MON810 Bt corn variety that is already outlawed in Hungary, Austria, Germany, Greece, and Luxembourg. The EU commission approved this crop in 2009, concluding that it “is as safe as its conventional counterpart with respect to potential effects on human and animal health”. In response to their publication the research team raised questions about the safety assessment procedure stating that their findings were a “surprising outcome and this risk was somehow overlooked” in past assessments of such crops. [1].

The research team led by Gilles-Eric Séralini at the University of Caen, France, is already well-known for their investigations on the endocrine disrupting effects of glyphosate herbicides (see [2] Glyphosate Kills Rat Testis Cells, SiS 54).The researchers tested the effects of Cry1Ab and Cry1Ac proteins as well as their combined effects with the herbicide Roundup on the human kidney cell line HEK293 [3]. Humans are exposed to hundreds of chemicals in a day, and their combined effects need to be understood. This is particularly important when considering the new generation of ‘stacked’ genetically modified (GM) crops now on the market, which carry multiple resistance genes for Bt toxins and glyphosate tolerance together.

Experiments were performed to assess both cell death and cell membrane integrity, as the pesticidal activity of Bt toxins results from creating pores in the membrane of cells in the insect gut. Cell death was measured using three parameters: 1) mitochondrial succinate dehydrogenase enzyme activity as a general cell death marker, 2) activity of the membrane-bound enzyme adenylate kinase (AK) to assess membrane integrity as a marker of necrotic cell death and 3) caspase 3/7 activity, as a marker of apoptosis (programmed cell death). They found that Cry1Ab caused cell death at concentrations of 100 parts per million (ppm), according to mitochondrial succinate dehydrogenase activity. The membrane-bound enzyme adenylate kinase (AK) goes up in activity when the membrane disintegrates and releases the enzyme into the culture medium. Cry1Ab at 100 ppm induced a 2-fold increase in AK activity. No effects were seen with Cry1Ac.

No increase in caspase 3/7 activity was observed with either Cry1Ab or Cry1Ac, suggesting that necrosis as opposed to apoptosis is the mechanism whereby Cry1Ab kills the cells.

Séralini’s team also assessed the effects of Roundup alone on the human kidney cells. Glyphosate at 57.2ppm (the LC50) that killed half of the cell population - 200 times below agricultural use - caused a 15-fold increase in AK activity and 6.7-fold increase in caspase 3/7 activity.

Interestingly, when Roundup was tested in combination with the Bt toxin, there was only one statistically significant effect: the increase in caspase 3/7 activity induced by 57.2 ppm glyphosate was halved in the presence of 10ppm of both Cry1Ab and Cry1Ac. There was also a non-significant trend of reduced AK leakage. The authors speculated that Bt proteins may affect the bioavailability of Roundup, thus delaying its apoptotic effects. The combined effects were not investigated in terms of glyphosate’s other known interactions with the cellular biochemistry such as endocrine disruptions. Further studies are needed to understand the combined effects of stacked herbicides and pesticides on the human body.

This study indicates that Bt toxins are not inert on human cells, and may indeed be toxic. As Bt toxins are produced by bacterial species existing naturally in the wild, and are used for organic agriculture, inadequate safety assessments were involved in the approval of Bt crops. Bacterial spores used in organic spraying could be washed away, but the Bt proteins are part and parcel of the GM crops. Furthermore, the Bt proteins in GM crops have been modified from those naturally produced, and the effects of these modification have not been addressed. Bt crops have previously been shown to induce hepatorenal abnormalities in rat feeding studies [4] as well as immune responses that may be responsible for allergies observed in farmers and factory workers handling Bt crops, affecting the eyes, skin and the respiratory tract (see [5] (More illnesses linked to Bt crops,SiS30). Reduced fertility in mice fed Bt maize has also been reported(see [6]GM Maize Reduces Fertility & Deregulates Genes in Mice,SiS41). These studies, along with the observation that Bt protein is present in the blood of pregnant women and their babies makes it an urgent matter for the health impacts of Bt proteins in GM crops to be thoroughly investigated along with the known effects on the environment and non-target species (see [7] Bt Crops Failures & Hazards, SiS 53).

Article first published 14/03/12


  1. Study questions safety of GM corn as France seeks EU ban,, 27th February 2012
  2. Sirinathsinghji E. Glyphosate Kills Rat Testes Cells. Science in Society 54, 2012, to appear.
  3. Mesnage R,Clair E, Gress S,Then C, Székács A,Séralini G-E. Cytotoxicity on human cells of Cry1Ab and Cry1Ac Bt insecticidal toxins alone or with a glyphosate-based herbicide. DOI 10.1002/jat.2712
  4. Spiroux de Vendômois J, Roullier F, Cellier D, Séralini GE. A comparison of the effects of three GM corn varieties on mammalian health. Int. J. Biol. Sci 2009, 5, 706 – 726.
  5. Ho MW. More illnesses linked to Bt crops.Science in Society 30, 8-10, 2006.
  6. Ho MW. GM maize reduces fertility & deregulates genes in mice.Science in Society 41, 40-41, 2009.
  7. Sirinathsinghji E. Bt Crops Failures & Hazards. Science in Society 53, 44-45, 2012

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There are 14 comments on this article so far. Add your comment above.

Rory Short Comment left 15th March 2012 04:04:11
The GM companies in their pursuit of profits are at war with their customers.

Lynne Habermacher Comment left 15th March 2012 17:05:37
A friend recently died of Parkinsons after some 35 years of the disease. It is thought it was due to pesticide use as a youngster. An uncle died of motor neuron disease, he also worked on a farm in the 50s and his wife was always certain it was the pesticides. He died 25 years ago after suffering for 15 years. thank you

Liz K Comment left 15th March 2012 17:05:50
When was this study done? It says "new" but I can't tell when this study took place. Could you provide a citation for the full article? I'd like to share it. Thanks!

Eva Comment left 15th March 2012 21:09:45
Hi Liz, The full reference is below. It was published on-line on the 15th February 2012. Mesnage R,Clair E, Gress S,Then C, Székács A,Séralini G-E. Cytotoxicity on human cells of Cry1Ab and Cry1Ac Bt insecticidal toxins alone or with a glyphosate-based herbicide. DOI 10.1002/jat.2712

Chris David Comment left 16th March 2012 17:05:16
They said DDT was bad also, even though it was developed to combat Malaria. When the U.S. banned it, the WHO followed suit. As a result, tens of millions worldwide continued to die of Malaria. It was said that DDT was harmful, when all the data said otherwise. Couldn't this also be a confabulation of real data?

Prince Awele Odor Comment left 16th March 2012 17:05:47
Why would anyone say that democracy is better than militarism or monarchy knowing that the corrupt, evil, criminal, and satanic genetic RE-engineering was NOT carried out by the military or by monarchs, NO OTHER CRIME IS WORSE THAN IT, and the government of the USA and the producers of GMOs and GMFs are absolutely unrepentant; rather, even more determined and desperate impose GM foods and synthetic (GM) agricultural chemicals on sovereign, independent, and free governments and nations of the ENTIRE world? Tell me what is good about democracy if genetic RE-engineering and the imposition of deadly GM foods and synthetic agricultural chemicals are peculiar to democracy? Convince me that Alexander Pope was WRONG about the foolishness of contending on forms of government and NOT contending on the morals and moral obligations of forms of government and the best form of government on these bases. What do you think would have been done by the government of the USA if another government was doing all that it has been doing regarding genetic RE-engineering/biotech applications and GM foods? Why do we not do that and stop talking, writing and, literally, begging the government of the USA against its determined most corrupt, evil, criminal and satanic wish and interest?

Shayla Gold Comment left 19th March 2012 16:04:57
I'm in the midwest and 2 days ago I heard someone talking about "crybaby" and I decided to look into it. Cry1Ab. So this GMO corn would be best sold with the label "for decorative purposes only". To make it look like your pantry is full. This may explain why my utis and kidney problems have been acting up so I need antibiotics every 3 months. The modern corn I'm eating may be triggering the illness, if it isn't the Roundup in the farmland air. I guess if you eat as much corn as a grub, as some people do, that it will kill you like a grub.

Jisa Comment left 20th March 2012 16:04:45
@Prince Awele Odor No educated person believes democracy is a good form of government. It has been defined as (1) a lynch mob, (2) two wolves and a sheep deciding what to have for lunch, (3) a transitory state on the way to tyranny. The U.S. was designed as a constitutional republic but is now a fascist tyranny. The country has been undermined and enslaved by the global elite who have brain washed and dumbed down the American people to the point they no longer can think critically or understand their heritage. They are the primary victims of assaults by GMO's and other toxic foods, fluorodated water, chemtrail-poisoned air, deadly pharaceuticals and a brainwashing educational system and media. The following presentation by Dr. Russel Blaylock gives just a hint of what has happened. There are Americans who are resisting. Many are ridiculed and harrassed and some are imprisoned and even assasinated. It is not clear how this will end.

Nidster Comment left 31st March 2012 02:02:07
Jisa, agree. For anyone with a thrist for facts can follow my hearty recommendation to view the interviews given by Dr. Don M. Huber, one of the senior scientists in the U.S (Purdue University) about area of science that relates to genetically modified organisms (GMO). The link is to the 2nd hour of the interview.

Kikuga Comment left 8th November 2012 23:11:03
I have came here quite late to see this post. But I just wonder, as Bt toxin needs to be activated in the alkaline condition which is found in insects, how can it be activated in human which has an acidic gut? In the natural condition, Bt toxin consumed by human shouldn't be able to be activated due to the pH, left alone forming a pore and get into the kidney. I'd think that if Bt is going to harm anyone, it will probably cause a stomach ulcer, than killing the kidney.

Eva Sirinathsinghji Comment left 15th November 2012 05:05:36
Unfortunately, the Bt insecticidal proteins produced by GM plants are in soluble forms, and thus already biochemically activated, unlike those produced by the microorganism Bt, secreted as inactive precursors or protoxin. In this study, they exposed a human kidney cell line in culture to an activated form also.

Fatboye Comment left 8th January 2013 15:03:51
Cheap food kills the masses, but in Western cultures only, especially America. Read about the people the American liberals are killing worldwide with their ethanol mandates driving up corn prices. They are killing us slowly because it pays. Citizens of third-world nations don't have insurance and savings accounts to drain, so they are simply starved to death quickly.

Katy Comment left 8th January 2013 15:03:59
My landlord has been spraying roundup on my grass (against my knowledge), around my chook pen and edges. I picked this grassto feed them and my son plays in it (possibly wet as we didnt know it had been sprayed, they are not supposed to enter my yard! They wait until I leave) 2 chickens died mysteriously the other week. My 2yr old son and i eat the eggs raw in an egg flip every other night, Christmas night he was taken to hospital with a very red swollen penis, still urinating but not as much and complaining it was sore to touch. He'd been playing nappy-off in the back yard also. They tested his urine and did swabs and all came back totally clear of infection. Mystery? I'm beginning to think not! I am 24 wks pregnant (at 42 yrs) with son number 4, I was recently greatly alarmed to find he is totally MISSING a KIDNEY. All genetic testing was done to rule out a known cause and all was clear... Co-incidence? I'd like to hear from anyone who knows more about this urgently... do I have grounds to take this further? If my kids and I have been harmed by this, something should be done! Reading about miscarriages, I could even have lost the baby... horrifying thought!

Becca Comment left 22nd January 2013 20:08:52
It is not American "liberals" that are killing people worldwide, as was stated by Fatboye. The frame work for this was laid down by the first President Herbert Walker Bush during his administration. He had a deal with Monsanto to write the policy for the FDA, which treats recombinant DNA crops as being the same as conventional agriculture, even though the novel DNA comes from another species or even kingdom, like E-coli bacteria, which is grown in the presence of the herbicide, Roundup. Or the soil bacterium, Bacillus Thringensis which is used to change the DNA of cotton and corn (maize) worldwide so that this new cotton deterred pests. Time has shown that pests are now becoming resistant to Bt, just as certain weed species have become resistant to Roundup Ready seeds and the herbicide. So now the biotechnology-pesticide companies are genetically engineering seeds in triplicate with three additional weed killers to create an even more toxic crop, which is used to create food for livestock and people as well as fiber. But, let us be clear whom you are calling liberal. Progressive activists in the USA have fought against this, have funded a campaign for the right to know about GMO's in food, although we lost by a narrow margin in California; we took litigation to the U.S. Supreme Court and to the Court of Appeals against the USDA and the peddlers of this toxic agriculture, who are also putting family farmers out of business. The groundwork was put in place by a father and son, both Republican presidents. And, was carried to market by both Clinton-Gore and Obama-Biden Administrations, the later was based on stolen studies on any chemical that Republican supporters did not like, thanks to Bush-Cheney administration. The Administrations of Bush-Quayle who started this, and Bush-Cheney who allowed studies to be stolen from the U.S. EPA library were considered "conservatives" who conserved the unethical and immoral way of life of the vested interests. The so-called liberal administrations of Clinton-Gore and Obama-Biden received disinformaton from the biotech-pesticide industries. All studies in the U.S. EPA libraries had disappeared before Obama-Biden came into office, thanks to the unethical behavior of Bush and Cheney. People and governments are being potentially poison based on the unethical maneuvers which took place in the USA under Republican and Democratic administrations who have the biotechnology vested interests in position at the USDA, FDA, and EPA.