21 replies to this topic

[Balmung]

I came across this comment when researching C60 and was wondering if anybody can confirm the concerns this poster had.

"My other suspicion comes from the timing... the oldest lived animals were 66 months (5.5 years), and the paper was submitted in Jan 2012. Thus, the studies were begun in July 2006. Many of the papers they cite regarding the rationale for the dosing regimen were published AFTER the study had already begun. The paper providing the rationale for stopping at 7 months (due to accumulation of c60 in the liver) was not published until 2010, more than 3 years after they'd already stopped dosing! You can't cite something as rationale, when it wasn't even published when you were designing the study."

[AgeVivo]

Hello,
I've discussed numerous times with Baati et al. They are in contact with the other C60 researchers and get to know about ongoing experiments. Concerning gavage, one big reason why they stopped is that it is very stressful for rats. So when the first rat died, in the control group, from tumors, indicating that the rats were starting to be quite old, they thought it was probably not a good idea to continue the gavage.

[niner]

The paper providing the rationale for stopping at 7 months (due to accumulation of c60 in the liver) was not published until 2010

Where did this come from? This isn't my recollection of the stopping reason.

[Balmung]

Also, has anybody found something to refute the damages to dna/rna found in this article?

http://www.ncbi.nlm....pubmed/22661584

[Hebbeh]

I came across this comment when researching C60 and was wondering if anybody can confirm the concerns this poster had.

"My other suspicion comes from the timing... the oldest lived animals were 66 months (5.5 years), and the paper was submitted in Jan 2012. Thus, the studies were begun in July 2006. Many of the papers they cite regarding the rationale for the dosing regimen were published AFTER the study had already begun. The paper providing the rationale for stopping at 7 months (due to accumulation of c60 in the liver) was not published until 2010, more than 3 years after they'd already stopped dosing! You can't cite something as rationale, when it wasn't even published when you were designing the study."

I’ll merely re-post what I said originally at In The Pipeline (posting under the name “Virgil”)…
I find it VERY odd that they started dosing at 10 months (just a few months before the control rats started dying), and kept the therapy up for only 7 months, but the oldest lived rats went on for over 5 years. Really? In humans this would translate to taking C60 for most of your 30s, none before, none after, and living to 120. Something’s not right.
My other suspicion comes from the timing… the oldest lived animals were 66 months (5.5 years), and the paper was submitted in Jan 2012. Thus, the studies were begun on or before July 2006. Many of the papers they cite regarding the rationale for the dosing regimen were published AFTER the study had already begun. The paper providing the rationale for stopping at 7 months (due to accumulation of c60 in the liver) was not published until 2010, more than 3 years after they’d already stopped dosing! You can’t cite something as rationale, when it wasn’t even published back when you were designing the study (and actually, not published until well after you’d actually stopped the treatment).
I don’t see that the correction addresses this fundamental error in the citations regarding rationale. The methods section or the citations need to be corrected also.

vhedwig
June 28, 2012 at 1:28 pm

• The rationale for stopping at 7 months, as quoted in the paper, is because of the poor ability of rats to handle oral gavage, as they are sensitive to it. They didn’t want this to become a confounding factor, so after the first rat died, the prodecude was stopped.
  10 month old rats were used, as is standard protocol, and the reason for this is given explicitly.
  There is no problem with accumlating citations over the course of a study that runs for such a long time, as these are used in the discussion. Post hoc propter hoc does not apply here.
  The 2010 study on bio-accumulation is not the earliest, it is the latest….. but there are plenty of other generic studies that show problems with administering a high fat diet to rats long term, and this would have been a confounding factor. The 2010 study is the most recent, and reviews all the previous literature in its bibliography, so this body of literature is not directly quoted in the references. The problems of obesity, excessive steatosis, liver lipid degeneration, and insulin resistance for administering a high-oil diet to rats was well established at the time the study started. The rationale was NOT bio-accumulation of fullerene in the liver, as you incorrectly state.

• http://retractionwat...-note-problems/

Edited by Hebbeh, 30 September 2012 - 07:48 PM.

[Turnbuckle]

Also, has anybody found something to refute the damages to dna/rna found in this article?

http://www.ncbi.nlm....pubmed/22661584

The damage is theoretical, but this work does suggest that C60 would be a methyltransferase inhibitor as it resides in the groove of DNA. And that is very likely how it works--by removing methyl groups in mtDNA and turning on genes that had been turned off.

[niner]

Also, has anybody found something to refute the damages to dna/rna found in this article?

http://www.ncbi.nlm....pubmed/22661584

That's just a molecular dynamics simulation, and it may well have been done incorrectly. Without backup from real organisms, it's next to meaningless. I don't believe there is any evidence suggesting that C60 causes damage to either DNA or RNA.

[niner]

Also, has anybody found something to refute the damages to dna/rna found in this article?

http://www.ncbi.nlm....pubmed/22661584

I looked into this simulation, and it has a lot of problems. For starters, the prototypical DNA structure they use is only an 8-mer. The fact that they can get it to unwind doesn't have much bearing on a full length structure. They used a relatively crude docking procedure to place the C60 in its initial location, then energy minimized it and equilibrated it with several hundred ps of MD. The problem is, they put a fairly large restraining potential (1000kJ nm(-2)) on the structure, so their energy minimization and MD resulted in a structure that was still of very high energy. Displacement of the C60 by only half an Angstrom would have raised the energy by ~60 kcal/m, significantly greater than the binding energies they reported. When they released the constraints and did more MD, it fell apart. Not surprising, imho. It also appears that they modeled the C60 atoms as Van der Waals spheres, with no account taken of the polarizability and electronic nature of the molecule. I could go on, but suffice it to say that there isn't a take-home message from this simulation. I'm going into detail here because I don't want this paper to be the start of an internet myth that "fullerenes are mutagenic". If someone can demonstrate an effect in a cell, or even an effect from C60 on the melting temperature of nucleic acids in solution, then there would be something to consider. At this point, there's not.

[Balmung]

Also, has anybody found something to refute the damages to dna/rna found in this article?

http://www.ncbi.nlm....pubmed/22661584

I looked into this simulation, and it has a lot of problems. For starters, the prototypical DNA structure they use is only an 8-mer. The fact that they can get it to unwind doesn't have much bearing on a full length structure. They used a relatively crude docking procedure to place the C60 in its initial location, then energy minimized it and equilibrated it with several hundred ps of MD. The problem is, they put a fairly large restraining potential (1000kJ nm(-2)) on the structure, so their energy minimization and MD resulted in a structure that was still of very high energy. Displacement of the C60 by only half an Angstrom would have raised the energy by ~60 kcal/m, significantly greater than the binding energies they reported. When they released the constraints and did more MD, it fell apart. Not surprising, imho. It also appears that they modeled the C60 atoms as Van der Waals spheres, with no account taken of the polarizability and electronic nature of the molecule. I could go on, but suffice it to say that there isn't a take-home message from this simulation. I'm going into detail here because I don't want this paper to be the start of an internet myth that "fullerenes are mutagenic". If someone can demonstrate an effect in a cell, or even an effect from C60 on the melting temperature of nucleic acids in solution, then there would be something to consider. At this point, there's not.

Thank you for looking into it. My chem knowledge isn't nearly the level of the posters around this forum. Thinking about testing some C60 but before I do I wanted some concerns addressed.

[smithx]

Also, has anybody found something to refute the damages to dna/rna found in this article?

http://www.ncbi.nlm....pubmed/22661584

The damage is theoretical, but this work does suggest that C60 would be a methyltransferase inhibitor as it resides in the groove of DNA. And that is very likely how it works--by removing methyl groups in mtDNA and turning on genes that had been turned off.

If you look back in the previous thread about this, I linked to studies which show that decreased methylation is associated with aging, not the reverse. So if C60 actually does decrease methylation, it would be likely to cause major problems, not benefits.

Saying that turning off methylation would provide benefits is similar to saying that the Mona Lisa would be improved if paint was randomly removed from parts of it. The methylation actually controls gene expression and allows cells to be differentiated. Without it, our cells would either die or become useless.

C60 certainly does not work by this mechanism, if it does work.

Edited by smithx, 02 October 2012 - 08:36 AM.

[Turnbuckle]

Also, has anybody found something to refute the damages to dna/rna found in this article?

http://www.ncbi.nlm....pubmed/22661584

The damage is theoretical, but this work does suggest that C60 would be a methyltransferase inhibitor as it resides in the groove of DNA. And that is very likely how it works--by removing methyl groups in mtDNA and turning on genes that had been turned off.

If you look back in the previous thread about this, I linked to studies which show that decreased methylation is associated with aging, not the reverse. So if C60 actually does decrease methylation, it would be likely to cause major problems, not benefits.

Saying that turning off methylation would provide benefits is similar to saying that the Mona Lisa would be improved if paint was randomly removed from parts of it. The methylation actually controls gene expression and allows cells to be differentiated. Without it, our cells would either die or become useless.

C60 certainly does not work by this mechanism, if it does work.

The studies showing a link between decreased methylation and aging apply to nDNA, I believe, but C60 accumulates in the mitochondria, not the nucleus. Hypomethylation is bad for nDNA because methylation is how cells distinguish themselves, and global hypomethylation has been associated with aging.

For mtDNA the picture is different. While a decrease in mtDNA methylation has been found with the culture age of immortal cells, they are still immortal, while an increase of mtDNA methylation has been associated with apoptosis of motor cell neurons.

There are very few mtDNA genes and its not even clear why methylation would be needed at all for such a stripped down genome. Some researchers initially believed that there was no methylation, but it is there, of course, and presumably not by accident. Perhaps it is there to tune mitochondria to different diets? For whatever reason, I believe what was done with intermittent dosing of rats with either C60 or procaine created epigenetic mutations in a population of modified bacteria (because that is what mitochondria are, essentially) while the rest periods let selection processes pick out the best ones for replication. It is not so much the overall level of methylation that is important, you see, but where that methylation is.

As for your analogy of random changes to the Mona Lisa, I agree with that to a degree, but only for nDNA. And I don't agree completely because cells are constantly painting on the DNA canvas. It's a work in progress.

[Ames]

mods:

imo, this thread should be moved to the section designated solely for C60 threads, so as to keep the discussion more easily available to everyone interested in C60.

back on topic:

Reversing DNA methylation: new insights from neuronal activity-induced Gadd45b in adult neurogenesis.

http://www.ncbi.nlm....pubmed/19336837

Abstract

Neurogenesis in the adult mammalian brain involves activity-dependent expression of genes critical for the proliferation of progenitors and for neuronal maturation. A recent study suggests that the stress response gene Gadd45b (growth arrest and DNA-damage-inducible protein 45 beta) can be transiently induced by neuronal activity and may promote adult neurogenesis through dynamic DNA demethylation of specific gene promoters in adult hippocampus. These results provide evidence supporting the provocative ideas that active DNA demethylation may occur in postmitotic neurons and that DNA methylation-mediated dynamic epigenetic regulation is involved in regulating long-lasting changes in neural plasticity in mammalian brains.

The epigenetic bottleneck of neurodegenerative and psychiatric diseases.

http://www.ncbi.nlm....atric diseases.

Abstract

The orchestrated expression of genes is essential for the development and survival of every organism. In addition to the role of transcription factors, the availability of genes for transcription is controlled by a series of proteins that regulate epigenetic chromatin remodeling. The two most studied epigenetic phenomena are DNA methylation and histone-tail modifications. Although a large body of literature implicates the deregulation of histone acetylation and DNA methylation with the pathogenesis of cancer, recently epigenetic mechanisms have also gained much attention in the neuroscientific community. In fact, a new field of research is rapidly emerging and there is now accumulating evidence that the molecular machinery that regulates histone acetylation and DNA methylation is intimately involved in synaptic plasticity and is essential for learning and memory. Importantly, dysfunction of epigenetic gene expression in the brain might be involved in neurodegenerative and psychiatric diseases. In particular, it was found that inhibition of histone deacetylases attenuates synaptic and neuronal loss in animal models for various neurodegenerative diseases and improves cognitive function. In this article, we will summarize recent data in the novel field of neuroepigenetics and discuss the question why epigenetic strategies are suitable therapeutic approaches for the treatment of brain diseases.

Methionine-deficient diet extends mouse lifespan, slows immune and lens aging, alters glucose, T4, IGF-I and insulin levels, and increases hepatocyte MIF levels and stress resistance.

http://www.ncbi.nlm....pubmed/15924568

Abstract

A diet deficient in the amino acid methionine has previously been shown to extend lifespan in several stocks of inbred rats. We report here that a methionine-deficient (Meth-R) diet also increases maximal lifespan in (BALB/cJ x C57BL/6 J)F1 mice. Compared with controls, Meth-R mice have significantly lower levels of serum IGF-I, insulin, glucose and thyroid hormone. Meth-R mice also have higher levels of liver mRNA for MIF (macrophage migration inhibition factor), known to be higher in several other mouse models of extended longevity. Meth-R mice are significantly slower to develop lens turbidity and to show age-related changes in T-cell subsets. They are also dramatically more resistant to oxidative liver cell injury induced by injection of toxic doses of acetaminophen. The spectrum of terminal illnesses in the Meth-R group is similar to that seen in control mice. Studies of the cellular and molecular biology of methionine-deprived mice may, in parallel to studies of calorie-restricted mice, provide insights into the way in which nutritional factors modulate longevity and late-life illnesses.

How to re-energise old mitochondria without shooting yourself in the foot.

http://www.ncbi.nlm....pubmed/12014827

Abstract

In old humans and pathologies associated with mitochondrial mutations, deletions in mitochondrial DNA have been associated with failing function. Investigations have been reported where treatment with a number of micronutrients, such as coenzyme Q10, have been used to re-energise failing tissues. Bioenergy changes in ageing Drosophila have been observed which indicate similar changes in mitochondrial function in old age. Reserves of carbohydrate and fat fall and food intake rises. Biochemical changes include falling mitochondrial enzymes. Mitochondrial DNA contains increased amounts of sequences corresponding to deletions. Both coenzyme Q10 and nicotinamide in large doses successfully reversed bioenergy changes in aged Drosophila. However, only nicotinamide was able to reduce short term mortality and increase life span, whereas coenzyme Q10 increased mortality and reduced life span. Production of reactive oxygen species (ROS) was increased in coenzyme Q10 treated flies, whereas nicotinamide reduced ROS production. It is suggested that ROS production may account for these longevity differences. Large doses of two micronutrients have been successful in reversing the age-associated bioenergy deficit in Drosophila. This response is similar to clinical reports of re-energising tissues where mitochondrial damage has been observed. However, this work highlights a danger for some micronutrients, such as coenzyme Q10, that clinical efficacy may be limited by increased ROS production.

I found the last study after realizing that ubiquinone was a methyl donor. I choose to interpret the last study through that lens, not just from the perspective of ROS. I won't be taking it. I know that the methyl donor / methylation issue is contested as far as life extension goes, and to each their own.

Backstory: I have ocular migraines witch seem to be leading to glaucoma, and have systemic inflammation that has led to insulin resistance along with memory loss as a result. That's why I'm here. I was searching for studies on another methyl donor, riboflavin, for which there is evidence of migraine incidence attenuation. This is the first study that came up, when searching for it's effect on lifespan. I believe that it's quite appropriate to include, given the excitement over mehtylene blue here, and it's supposed role in mitochondrial support that in which it is roughly categorized along with C60. Both riboflavin and methylene blue are methyl donors, and I do acknowledge that the results of this study are inconsistent as far as that is concerned:

Influence of photosensitizers and light on the life span of Drosophila.

http://www.ncbi.nlm..../pubmed/8350657

Abstract

The life span of adult Drosophila melanogaster fruit flies changed when they were fed two different photosensitizers. Methylene blue decreased the median life span by 49% when present in the food at a concentration of 0.001 M. Another photosensitizer, riboflavin, produced no changes in life span under the same conditions of a 12:12 h light/dark cycle at a daytime light intensity of 1000 lux. Flies exposed to constant darkness lived 43.2% longer than those exposed to constant light at a light intensity of 2000 lux. Under these conditions, riboflavin increased the life span of the flies exposed to constant light by as much as 25%. We conclude that riboflavin confers some degree of protection against the effects of constant light exposure. The completely different results obtained with riboflavin and methylene blue suggest a possible mechanism for photoageing involving photodynamic action mediated through the production of singlet oxygen.

Edited by golgi1, 02 October 2012 - 08:30 PM.

[smithx]

For whatever reason, I believe what was done with intermittent dosing of rats with either C60 or procaine created epigenetic mutations in a population of modified bacteria (because that is what mitochondria are, essentially) while the rest periods let selection processes pick out the best ones for replication. It is not so much the overall level of methylation that is important, you see, but where that methylation is.

I actually think this is rather clever and retract my statement, with respect to mtDNA.

[niner]

mods:

imo, this thread should be moved to the section designated solely for C60 threads, so as to keep the discussion more easily available to everyone interested in C60.

Yes, it should be grouped with the other C60 threads, I agree. I'll go ahead and do that, but I think that the C60 forum itself should be located under supplements, as it has nothing to do with nanotech, and everything to do with bioscience.

How to re-energise old mitochondria without shooting yourself in the foot.

http://www.ncbi.nlm....pubmed/12014827

In old humans and pathologies associated with mitochondrial mutations, deletions in mitochondrial DNA have been associated with failing function. Investigations have been reported where treatment with a number of micronutrients, such as coenzyme Q10, have been used to re-energise failing tissues. Bioenergy changes in ageing Drosophila have been observed which indicate similar changes in mitochondrial function in old age. Reserves of carbohydrate and fat fall and food intake rises. Biochemical changes include falling mitochondrial enzymes. Mitochondrial DNA contains increased amounts of sequences corresponding to deletions. Both coenzyme Q10 and nicotinamide in large doses successfully reversed bioenergy changes in aged Drosophila. However, only nicotinamide was able to reduce short term mortality and increase life span, whereas coenzyme Q10 increased mortality and reduced life span. Production of reactive oxygen species (ROS) was increased in coenzyme Q10 treated flies, whereas nicotinamide reduced ROS production. It is suggested that ROS production may account for these longevity differences. Large doses of two micronutrients have been successful in reversing the age-associated bioenergy deficit in Drosophila. This response is similar to clinical reports of re-energising tissues where mitochondrial damage has been observed. However, this work highlights a danger for some micronutrients, such as coenzyme Q10, that clinical efficacy may be limited by increased ROS production.

I found the last study after realizing that ubiquinone was a methyl donor. I choose to interpret the last study through that lens, not just from the perspective of ROS. I won't be taking it. I know that the methyl donor / methylation issue is contested as far as life extension goes, and to each their own.

Backstory: I have ocular migraines witch seem to be leading to glaucoma, and have systemic inflammation that has led to insulin resistance along with memory loss as a result. That's why I'm here. I was searching for studies on another methyl donor, riboflavin, for which there is evidence of migraine incidence attenuation. This is the first study that came up, when searching for it's effect on lifespan. I believe that it's quite appropriate to include, given the excitement over mehtylene blue here, and it's supposed role in mitochondrial support that in which it is roughly categorized along with C60. Both riboflavin and methylene blue are methyl donors...

Neither ubiquinone, riboflavin, nor methylene blue are methyl donors as we normally think of them. Methylene blue is a facile electron transfer agent that can boost a defective Electron Transport Chain in the mitochondria, and it is conceivable that C60 might work that way, although I don't think there is any hard evidence to that effect. The vast majority of methylene blue discussion here has involved doses that are too low to produce the ETC effect, though they are at least very placebogenic, if nothing else.

[niner]

There are very few mtDNA genes and its not even clear why methylation would be needed at all for such a stripped down genome. Some researchers initially believed that there was no methylation, but it is there, of course, and presumably not by accident. Perhaps it is there to tune mitochondria to different diets? For whatever reason, I believe what was done with intermittent dosing of rats with either C60 or procaine created epigenetic mutations in a population of modified bacteria (because that is what mitochondria are, essentially) while the rest periods let selection processes pick out the best ones for replication. It is not so much the overall level of methylation that is important, you see, but where that methylation is.

Maybe the methyl groups on mtDNA are just there. Given the tiny genome, it's kind of hard to imagine how you'd get a benefit out of shutting expression of any of them off, if such mechanisms even exist for the mitochondrial genome. I don't see where the selection pressure is coming from either. Is there a mechanism that selectively replicates good mitochondria and kills bad ones? There are situations where the opposite occurs- the sick mitochondria are replicated and the good ones aren't. These are cases where the bad mitochondria are creating excessive ROS. This epigenetic hypothesis is completely evidence-free. It all hinges on the dubious MD simulation discussed above, and the notion that procaine is a DNA groove binder, though I can find no evidence to that effect, nor does it really look like a DNA binder.

You've said you don't buy the redox hypothesis, because other antioxidants don't extend lifespan. The traditional antioxidants don't extend life because they don't get into the mitochondria where the ROS are generated. They are also, by and large, fairly lousy at dealing with ROS anyway. There is a class of antioxidants that were designed to get into the mitochondria; the Skulachev ions. I believe they have been shown to extend lifespan in some organisms, but the antioxidant part of the molecule was plastoquinone, a not-so-great choice. The C60-fatty acid adducts should have structures that are similar to Skulachev ions, and indeed, have been shown to localize to the mitochondria. More importantly, the antioxidant part, C60, has a spectacular ability to deal with ROS, and has been demonstrated to have superoxide dismutase mimetic behavior. So that's two pieces of hard evidence: they localize to mitochondria and they have been shown to dismutate superoxide, the major type of ROS. The stumbling block, as I understand it, lies in explaining how the C60 could have an effect lasting far beyond the final dose. I think this can be explained by the following: The effective dose of C60 for a human, based on the experiences of people posting here, is as little as one milligram. For rats, it would be in the low micrograms, on this basis. On a simple mg/kg basis, the rats were getting 140 times what I'll take to be the minimum human dose. If we assume the minimal human dose is only enough for one day, which I suspect is very conservative, then the 24 doses given to the rats would be enough for over 9 years. Mitochondria don't last very long, but they are efficiently recycled. I contend that the 24 huge doses given to Baati's rats loaded their membranes to the hilt with C60-oo, and that it took a long time for it to fall below the minimal effective concentration. It's not even necessary that it lasted their entire lifetime; just long enough to prevent a couple years worth of oxidative damage. For all we know, if the rats had been dosed a few more times in their older age, they might have lived even longer.

[Balmung]

In this study http://www.ncbi.nlm....les/PMC2186061/
They found "Exposure to C₆₀ induced both necrotic and apoptotic cellular death throughout the embryo."
This sounds rather frightening, as there were some pretty series negative effects from the fullerene throughout the study.

Is there any reason why this toxicity would not be relevant for the rats/humans?

[Turnbuckle]

In this study http://www.ncbi.nlm....les/PMC2186061/
They found "Exposure to C₆₀ induced both necrotic and apoptotic cellular death throughout the embryo."
This sounds rather frightening, as there were some pretty series negative effects from the fullerene throughout the study.

Is there any reason why this toxicity would not be relevant for the rats/humans?

I think you have to be careful with any substance that might have an epigentic effect on embryos. Unfortunately, this study confounded the results by dissolving C60 in DMSO, which has proven epigenetic effects--

Dimethyl Sulfoxide Has an Impact on Epigenetic Profile in Mouse Embryoid Body

Southern blot analysis revealed that DMSO caused hypermethylation of two kinds of repetitive sequences in EBs. Furthermore, restriction landmark genomic scanning, by which DNA methylation status can be analyzed on thousands of loci in genic regions, revealed that DMSO affected DNA methylation status at multiple loci, inducing hypomethylation as well as hypermethylation depending on the genomic loci.

DMSO is a strong inducer of DNA hydroxymethylation in pre-osteoblastic MC3T3-E1 cells

And this study found that C60 dissolved in DMSO was even worse for embryos than C60 dissolved in toluene when it came to morphological malformations--

Effect of preparation methods on toxicity of fullerene water suspensions to Japanese medaka embryos.

The malformations of DMSO/nC(60) might have originated from the co-effect of organic solvent remaining in the fullerene colloid.

[niner]

In this study http://www.ncbi.nlm....les/PMC2186061/
They found "Exposure to C₆₀ induced both necrotic and apoptotic cellular death throughout the embryo."
This sounds rather frightening, as there were some pretty series negative effects from the fullerene throughout the study.

Is there any reason why this toxicity would not be relevant for the rats/humans?

This is a pretty clever study, in that they seem to have a good system (zebrafish embryos) for looking at effects on development, and those effects are pertinent in some cases to effects on mature organisms. That much of it, I like. However, this was performed back in the era of the "toxic aqueous solutions of C60" that turned out to be artifacts of the way they created the solutions, starting with a THF solution. In this case, they used DMSO instead of THF, but they sonicated the water solutions for a long time. Pristine C60 isn't super stable in water, particularly under sonication, so I'd argue that we don't really know what the fish were exposed to. The C60(OH)24 was an order of magnitude less toxic, and it was sonicated an order of magnitude less than the pristine C60. Coincidence?

The embryos had their outer coatings enzymatically ablated to improve the bioavailability of the C60 they were soaking in. In terms of exposure, this is probably similar to a human getting an iv injection, except that the embryos don't have any xenobiotic metabolism, and we do. It's hard to compare their dosage to ours, but the entire time they are soaking in the 200ppb (0.2mg/kg) solution, the (presumably still) hydrophobic C60 compound is partitioning into the embryonic lipids. The final dose may be substantially more than 0.2 mg/kg based on the weight of the embryo. There are just so many question marks here; I don't want to totally dismiss this work, but I lean more heavily on the work in various species via more physiologically relevant dosing that shows mainly positive effects on health.

[BandOnTheRun]

Also, has anybody found something to refute the damages to dna/rna found in this article?

http://www.ncbi.nlm....pubmed/22661584

I looked into this simulation, and it has a lot of problems. For starters, the prototypical DNA structure they use is only an 8-mer. The fact that they can get it to unwind doesn't have much bearing on a full length structure. They used a relatively crude docking procedure to place the C60 in its initial location, then energy minimized it and equilibrated it with several hundred ps of MD. The problem is, they put a fairly large restraining potential (1000kJ nm(-2)) on the structure, so their energy minimization and MD resulted in a structure that was still of very high energy. Displacement of the C60 by only half an Angstrom would have raised the energy by ~60 kcal/m, significantly greater than the binding energies they reported. When they released the constraints and did more MD, it fell apart. Not surprising, imho. It also appears that they modeled the C60 atoms as Van der Waals spheres, with no account taken of the polarizability and electronic nature of the molecule. I could go on, but suffice it to say that there isn't a take-home message from this simulation. I'm going into detail here because I don't want this paper to be the start of an internet myth that "fullerenes are mutagenic". If someone can demonstrate an effect in a cell, or even an effect from C60 on the melting temperature of nucleic acids in solution, then there would be something to consider. At this point, there's not.

In an actual cell, if the DNA were straightened then one might expect that the sheltering complex in somatic cells and stems would uncurl. If this were the case, in stem cells, then the telomerase produced in the stem cell would lengthen the telomeres. If the telomeres were lengthened we would have a younger more potent stem cell. What sort of noticeable effect would we witness if this were the case? In old rats and mice we would perhaps see neurogenesis or the reversal of arthritis (new cartilage forming). In the literature we do in fact see both of these events. So I don't think we can not take this nanotoxicity model lightly.

What would this mean to a human? If the sheltering complex is uncurled then telomerase activators would be more effective.
Is the the type of vitamin E in olive a telomerase activator? Tocotrienols is a telmerase activator and a form of vitamin E, is it found in olive oil ? Is c60 itself a telomerase activator?
I don't know the answers to the above.

[niner]

In an actual cell, if the DNA were straightened then one might expect that the sheltering complex in somatic cells and stems would uncurl. If this were the case, in stem cells, then the telomerase produced in the stem cell would lengthen the telomeres. If the telomeres were lengthened we would have a younger more potent stem cell. What sort of noticeable effect would we witness if this were the case? In old rats and mice we would perhaps see neurogenesis or the reversal of arthritis (new cartilage forming). In the literature we do in fact see both of these events. So I don't think we can not take this nanotoxicity model lightly.

What would this mean to a human? If the sheltering complex is uncurled then telomerase activators would be more effective.
Is the the type of vitamin E in olive a telomerase activator? Tocotrienols is a telmerase activator and a form of vitamin E, is it found in olive oil ? Is c60 itself a telomerase activator?
I don't know the answers to the above.

If pigs had wings, they could fly... I don't see how you can connect telomerase action to DNA unwinding, and there are plenty of other ways to explain the results we see with c60-oo without having to invoke an argument that at its core is based on a terribly flawed simulation. There isn't enough of anything in a few ml of olive oil to activate telomerase. Bill Andrews has looked at an awful lot of natural products in this regard, and if there was anything that potent in olive oil, I think we'd know by now.

[BandOnTheRun]

Again regarding nanotoxicity of C60 binding with guanine and disrupting normal function of the cell DNA.
http://144.206.159.1...91/12569479.pdf

I'm not postulating any theories as to what impact this has, whether positive or negative. Just read the article
and come to your own conclusions using the insights of the well educated on this board.

[niner]

Again regarding nanotoxicity of C60 binding with guanine and disrupting normal function of the cell DNA.
http://144.206.159.1...91/12569479.pdf

I'm not postulating any theories as to what impact this has, whether positive or negative. Just read the article
and come to your own conclusions using the insights of the well educated on this board.

This is a quantum mechanical calculation of the structures and energies of three different complexes between pristine C60 and unattached guanine in a vacuum. The pi-stacking complex, not surprisingly, shows a stabilization of 8-9 kcal/mol. The natural question would be: "Does this mean anything bad for people taking c60-oo?" In my opinion it does not. Chemical physicists love to do big QM calculations, and it's always fun for a grad student to do one that sounds like it has relevance to human health. That makes it a lot easier to get it published. The problem with chemical physicists is that they often don't know very much about biological systems, pharmacokinetics, and metabolism, which sometimes causes them to set up calculations that don't have much bearing on reality. In our case, the compound that we're taking in all likelihood consists mostly of oleic acid bis-adducts to c60, and given their amphiphilic nature, will primarily be found in membranes. As such, they wouldn't have much access to DNA, and would probably be sterically prevented (by their large fatty acid substituents) from engaging in the sort of DNA interactions postulated in this thread.

In order to be concerned about genotoxicity, I would at least want to see a genotoxic effect from c60-oo (not from photoexcited aggregates or other dissimilar compounds) in some kind of life form, even in cells. I'd even take notice if C60-oo were to alter the melting temperature of DNA in water, which is a measure of DNA stability. Of course, absence of evidence is not evidence of absence. The only experiments we have to date are Baati's rats, who lived a long time and didn't get cancer, AgeVivo's mice, one of which died of what was probably a pre-existing tumor, and several thousand human guinea pigs, some of whom post here.