635 replies to this topic

[sensei]

 

 

Sensei's right; it's really hard to get things into c60.  You have to synthesize the c60 around the atom you want to enclose, and one atom is about all there's room for.  C60 does not act as a shuttle, either into or out of the cell.  C60 also doesn't form nanotubes, at least not at biological temperatures.

 

 

C60 compounds penetrate the cellular membrane

 

"In addition, a novel cystine fullerene derivative can penetrate through the cell membrane and has played a distinct role in protecting PC 12 cells (rat pheochromocytoma cell line) against hydrogen peroxide-induced cytotoxicity (Hu et al., 2007)."

 

http://www.ncbi.nlm....les/PMC3834498/

 

 

----

 

C60 can form compounds with molecules that do bind and ferry waste out of the cell -->

 

C60 is known to form a 2-1 inclusion compound with C60-- cyclodextrin (2) -C60 (1) 2 molecules of cyclodextrin wrap around C60

 

Cyclodextrin binds lipofuscin and removes it from the cell -- http://www.ncbi.nlm....pubmed/24706818

Edited by sensei, 13 February 2015 - 01:47 AM.

[pone11]

 

 

Has any study actually looked at what gets trapped inside the nanotubes that C60 forms to see what kind of cellular debris ends up there?    

 

I'm not aware that C60 forms nanotubes. As far as I'm aware -- it takes alot of energy to open a buckyball.  AFAIK, most things form inclusion compounds (they surround the C60 molecule), or simply attach to the outside, like poly-hydroxylated C60.

 

 

It doesn't change any of my questions.

[pone11]

Which paper suggests that c60 acts like catalase?  I'm not sure which one you're talking about there, and don't recall seeing it.

 

 

Sensei posted a link to this study, which suggests a protective effect from C60 against H2O2:

http://www.ncbi.nlm....pubmed/18986699

 

I can't get the full text for the study, so I don't know the details of the mechanism for this.

 

I am not trying to say that C60 behaves chemically like catalase behaves.  I am saying that it is fulfilling the role that catalase fills, by - apparently - neutralizing H2O2.  The actual details of how C60 does this might be quite different from how catalase does that.  And supplemental catalase might still have a synergistic role here.

[niner]

 

Which paper suggests that c60 acts like catalase?  I'm not sure which one you're talking about there, and don't recall seeing it.

 

Sensei posted a link to this study, which suggests a protective effect from C60 against H2O2:

http://www.ncbi.nlm....pubmed/18986699

 

I can't get the full text for the study, so I don't know the details of the mechanism for this.

 

I am not trying to say that C60 behaves chemically like catalase behaves.  I am saying that it is fulfilling the role that catalase fills, by - apparently - neutralizing H2O2.  The actual details of how C60 does this might be quite different from how catalase does that.  And supplemental catalase might still have a synergistic role here.

 

Ok.  I don't think it neutralizes the peroxide, but it probably acts as a chain breaker in the free radical propagation process that H2O2 sets off.  Catalase would cleanly take care of hydrogen peroxide, while the way I hypothesize c60 works, you might get a little damage, but not as much as you would get without either c60 or catalase.

[Logic]

I have a theory on one of the ways in which C60oo may be working:
ROS damages DNA.
PARP is instrumental in DNA repair.
PARP requires NAD+.
As the amount of ROS increase; the amount of NAD+ required by PARP increases, leaving less for SIRT etc. and its longevity effects.
 
ie: C60oo cuts the amount of ROS; leading to less DNA damage; leading to less need for PARP; leading to an increase in available NAD+ available for SIRTs etc; leading to the lifespan increase seen in Baati's experiment.
 
Thoughts?

 
I am not going to pass judgement on the specific mechanism, but I am going to invoke Occam's Razor and ask why do we need this theory to accomplish anything useful?
 
To me, the basic problem is clear as night and day.  Denham Hardam originally proposed the free radical theory of aging, and in recent years that has been focused to the mitochondrial ROS theory of aging.   Mitochondria do a poor job of fixing damage to their DNA, so they are particularly susceptible to the effects of ROS.     What's critical to realize is that aerobic metabolism and electron transport chain (ETC) reside on the inner mitochondrial membrane.   So the mitochondria are in fact the source of most of the ROS - as a byproduct of the use of oxygen within the complexes of the ETC - and those delicate inner membranes are the ones that are then subjected to the effects of ROS most directly.   
 
The most basic ROS reaction is the production of superoxide radical in aerobic metabolism.   Superoxide is converted to hydrogen peroxide (H2O2) by SOD.   H2O2 is then converted to water and O2 by catalase.    In fighting mitochondrial aging, it is key to find a way to neutralize those superoxide radicals - in the mitochondria where they are being formed! - and transform them into something harmless.    
 
When we are young, our endogenous levels of SOD and catalase are sufficiently high to prevent serious damage to mitochondria.  When we are old, or sick, or have some mitochondrial disease, the levels of SOD and catalase fall - or the levels of ROS rise above what endogenous SOD and catalase can handle - and the mitochondria accumulate damage from ROS.
 
The papers quoted earlier in this subthread propose that C60+OO might act as an SOD mimic, and the second paper proposes some additional mechanism by which it performs a job similar to catalase.   This all fits in beautifully with our understanding of ROS in mitochondria.   It suggests very very clearly how C60+OO acts functionally to extend life, by preventing damage to mitochondria from ROS.  
 
Given that disclosure, why do we need your more complex theory with PARP and NAD+?   What does it help us accomplish?

My hypothesis is a little off topic to current conversation here (very interesting), but not to the thread title...
My theory, IF correct, helps us understand why C60oo has a dramatic life extending effect, which is the ultimate question being asked in this thread IMHO?

I certainly agree that its the ROS produced by mitochondria that is in all probability most addressed by C60oo and is the most important source to address.
I am thinking about the downstream affects of quenching mitochondrial ROS:

Doing so should result in less ROS damage to DNA in the nucleus and hence more SIRT etc activation and all it downstream effects..??? (this is the point I am seeking feedback/opinions on)
 

Another point to consider is that telomerase in the nucleus travels to mitochondria to help with ROS issues there.
If there are less ROS issues in the mitochondria; its likely there will be less telomere shortening and possibly even telomere lengthening...?

[APBT]

 

Which paper suggests that c60 acts like catalase?  I'm not sure which one you're talking about there, and don't recall seeing it.

 

 

Sensei posted a link to this study, which suggests a protective effect from C60 against H2O2:

http://www.ncbi.nlm....pubmed/18986699

 

I can't get the full text for the study, so I don't know the details of the mechanism for this.

 

 

FULL TEXT:  

Attached Files

•  The scavenging of reactive oxygen species and the potential for cell protection.pdf   969.59KB   30 downloads

[pone11]

 

 

Which paper suggests that c60 acts like catalase?  I'm not sure which one you're talking about there, and don't recall seeing it.

 

 

Sensei posted a link to this study, which suggests a protective effect from C60 against H2O2:

http://www.ncbi.nlm....pubmed/18986699

 

I can't get the full text for the study, so I don't know the details of the mechanism for this.

 

 

FULL TEXT:  

 

 

Thanks for the full text.   So what is the issue with the study preferring the water soluble form of C60?   Since C60+OO is apparently the non water soluble form - delivered in a lipid - does that limit where it can act compared to the soluble forms?

 

Has anyone read the study and determined if the concentrations of C60 they are using in vitro are in any way comparable to the concentrations we might get in vivo taking the usual quantities of C60+OO that people have been taking?  I assume the in vivo concentrations must be much lower than what is in this study?

 

After reading the study, it looks like C60 does nothing to neutralize H2O2.  Rather, C60 handles the ROS that are generated as a byproduct of H2O2.   You still very much want catalase levels as high as possible to deal with converting H2O2 to something harmless.

 

Edited by pone11, 14 February 2015 - 03:06 AM.

[niner]

 

Sensei's right; it's really hard to get things into c60.  You have to synthesize the c60 around the atom you want to enclose, and one atom is about all there's room for.  C60 does not act as a shuttle, either into or out of the cell.  C60 also doesn't form nanotubes, at least not at biological temperatures.

 

C60 compounds penetrate the cellular membrane

 

http://www.ncbi.nlm....les/PMC3834498/

----

C60 can form compounds with molecules that do bind and ferry waste out of the cell -->

C60 is known to form a 2-1 inclusion compound with C60-- cyclodextrin (2) -C60 (1) 2 molecules of cyclodextrin wrap around C60

Cyclodextrin binds lipofuscin and removes it from the cell -- http://www.ncbi.nlm....pubmed/24706818

 

Cyclodextrin is a cyclic compound with a large hydrophobic cavity and a hydrophilic exterior.  Hydrophobes like c60 or the lipofuscin bisretinoids mentioned in that paper, or a ton of other drugs that are too hydrophobic to dissolve in water (e.g. resveratrol) will nestle in the hydrophobic cavity and thus be able to be dissolved in water.  However, if c60 is binding in the cavity, then nothing else will bind in it.   The notion that c60 binds to things and carries them either into or out of the cell is a popular meme that keeps coming up on this forum, but it just doesn't happen.

[pone11]

Can someone explain the details of how C60 quelches a free radical?   A free radical normally is missing an electron from an electron pair.  The radical does it damage by pulling an electron off of a fully formed atom and rendering that target unstable.   At the level of electrons, C60 is not just sharing an extra electron to render the free radical stable, but seems to be somehow binding to the free radical and trapping it.    How does C60 trap a free radical and bind it to the C60 structure?   

 

And the related question:  if C60 has some charge characteristic(s) that make it attract free radicals, how do we know that this charge will not also attract enzymes, peptides, or minerals that the body needs?   In other words, how can we know that C60 is selective in attracting only free radicals?

Edited by pone11, 17 February 2015 - 07:48 AM.

[Kalliste]

Here is an older article about PEG-HCC's. I've browsed this thread once or twice and I can't recall if this was ever posted. The part about making the liver cells live longer is eerily reminiscent of Baathis study.

 

http://news.rice.edu...-flow-in-brain/

http://pubs.acs.org/....1021/nn302615f

 

 

Nanoparticles reboot blood flow in brain
Rice University, Baylor College of Medicine discovery might aid emergency care of traumatic brain-injury victims

HOUSTON – (Aug. 23, 2012) – A nanoparticle developed at Rice University and tested in collaboration with Baylor College of Medicine (BCM) may bring great benefits to the emergency treatment of brain-injury victims, even those with mild injuries.

Combined polyethylene glycol-hydrophilic carbon clusters (PEG-HCC), already being tested to enhance cancer treatment, are also adept antioxidants. In animal studies, injections of PEG-HCC during initial treatment after an injury helped restore balance to the brain’s vascular system.

The results were reported this month in the American Chemical Society journal ACS Nano.

A PEG-HCC infusion that quickly stabilizes blood flow in the brain would be a significant advance for emergency care workers and battlefield medics, said Rice chemist and co-author James Tour.

“This might be a first line of defense against reactive oxygen species (ROS) that are always overstimulated during a medical trauma, whether that be to an accident victim or an injured soldier,” said Tour, Rice’s T.T. and W.F. Chao Chair in Chemistry as well as a professor of mechanical engineering and materials science and of computer science. “They’re certainly exacerbated when there’s trauma with massive blood loss.”

In a traumatic brain injury, cells release an excessive amount of an ROS known as superoxide (SO) into the blood. Superoxides are toxic free radicals, molecules with one unpaired electron, that the immune system normally uses to kill invading microorganisms. Healthy organisms balance SO with superoxide dismutase (SOD), an enzyme that neutralizes it. But even mild brain trauma can release superoxides at levels that overwhelm the brain’s natural defenses.

“Superoxide is the most deleterious of the reactive oxygen species, as it’s the progenitor of many of the others,” Tour said. “If you don’t deal with SO, it forms peroxynitrite and hydrogen peroxide. SO is the upstream precursor to many of the downstream problems.”

SO affects the autoregulatory mechanism that manages the sensitive circulation system in the brain. Normally, vessels dilate when blood pressure is low and constrict when high to maintain an equilibrium, but a lack of regulation can lead to brain damage beyond what may have been caused by the initial trauma.

“There are many facets of brain injury that ultimately determine how much damage there will be,” said Thomas Kent, the paper’s co-author, a BCM professor of neurology and chief of neurology at the Michael E. DeBakey Veterans Affairs Medical Center in Houston. “One is the initial injury, and that’s pretty much done in minutes. But a number of things that happen later often make things worse, and that’s when we can intervene.”

Kent cited as an example the second burst of free radicals that can occur after post-injury resuscitation. “That’s what we can treat: the further injury that happens because of the necessity of restoring somebody’s blood pressure, which provides oxygen that leads to more damaging free radicals.”

In tests, the researchers found PEG-HCC nanoparticles immediately and completely quenched superoxide activity and allowed the autoregulatory system to quickly regain its balance. Tour said ROS molecules readily combine with PEG-HCCs, generating “an innocuous carbon double bond, so it’s really radical annihilation. There’s no such mechanism in biology.” While an SOD enzyme can alter only one superoxide molecule at a time, a single PEG-HCC about the size of a large protein at 2-3 nanometers wide and 30-40 nanometers long can quench hundreds or thousands. “This is an occasion where a nano-sized package is doing something that no small drug or protein could do, underscoring the efficacy of active nano-based drugs.”

“This is the most remarkably effective thing I’ve ever seen,” Kent said. “Literally within minutes of injecting it, the cerebral blood flow is back to normal, and we can keep it there with just a simple second injection. In the end, we’ve normalized the free radicals while preserving nitric oxide (which is essential to autoregulation). These particles showed the antioxidant mechanism we had previously identified as predictive of effectiveness.”

The first clues to PEG-HCC’s antioxidant powers came during nanoparticle toxicity studies with the MD Anderson Cancer Center. “We noticed they lowered alkaline phosphatase in the liver,” Tour said. “One of our Baylor colleagues saw this and said, ‘Hey, this looks like it’s actually causing the liver cells to live longer than normal.’

“Oxidative destruction of liver cells is normal, so that got us to thinking these might be really good radical scavengers,” Tour said.

Kent said the nanoparticles as tested showed no signs of toxicity, but any remaining concerns should be answered by further tests. The researchers found the half-life of PEG-HCCs in the blood – the amount of time it takes for half the particles to leave the body – to be between two and three hours. Tests with different cell types in vitro showed no toxicity, he said.

The research has implications for stroke victims and organ transplant patients as well, Tour said.

Next, the team hopes to have another lab replicate its positive results. “We’ve repeated it now three times, and we got the same results, so we’re sure this works in our hands,” Kent said.

First authors of the paper are BCM graduate student Brittany Bitner, Rice graduate student Daniela Marcano and former Rice postdoctoral researcher Jacob Berlin, now an assistant professor of molecular medicine at the Beckman Research Institute of the City of Hope, Duarte, Calif. Co-authors are all at BCM: Roderic Fabian, associate professor of neurology; Claudia Robertson, professor of neurosurgery; Leela Cherian, research instructor of neurosurgery; Mary Dickinson, associate professor of molecular physiology; Robia Pautler, associate professor of molecular physiology; and James Culver, a graduate student in molecular physiology.

The research was funded by the Department of Defense’s Mission Connect Mild Traumatic Brain Injury Consortium, the National Science Foundation, the National Institutes of Health and the National Heart, Lung and Blood Institute.

- See more at: http://news.rice.edu...h.6EVJNOsG.dpuf

 

[Kalliste]

I have emailed some of the researchers behind the PEG's and informed them of lipofullerenes although I'm sure they are too busy with their own goodies to take notice.

[niner]

Can someone explain the details of how C60 quelches a free radical?   A free radical normally is missing an electron from an electron pair.  The radical does it damage by pulling an electron off of a fully formed atom and rendering that target unstable.   At the level of electrons, C60 is not just sharing an extra electron to render the free radical stable, but seems to be somehow binding to the free radical and trapping it.    How does C60 trap a free radical and bind it to the C60 structure?   

 

And the related question:  if C60 has some charge characteristic(s) that make it attract free radicals, how do we know that this charge will not also attract enzymes, peptides, or minerals that the body needs?   In other words, how can we know that C60 is selective in attracting only free radicals?

 

C60 has a very large conjugated system of alternating double and single bonds; a system that can accept or donate electrons easily and still remain very stable.  Depending on how many electrons it has accepted or donated, it could have a negative, neutral, or positive charge.  It doesn't have to trap and bind the radical; all that has to happen is for the radical to bump into it.  While there might be some transient binding of other molecules to c60, it appears to act catalytically, so that it is unchanged by the overall process, otherwise it would quickly be used up. 

 

When a superoxide anion hits a neutral fullerene, it most likely transfers an electron to fullerene, liberating an oxygen molecule.  The fullerene is happy to sit there with a widely dispersed negative charge, and will eventually donate it to another electron acceptor.  Other superoxide molecules, in concert with protons from the surrounding aqueous medium can serve as electron acceptors in a reaction that produces H2O2.  That's what happens in SOD, and fullerenes have been shown to have SOD-mimetic activity.

 

Fullerenes are unlikely to attract biomolecules, although if a small, mobile cation happened by, it would probably be attracted to a negatively charged reduced fullerene.  Exactly what would happen would depend on the nature of the cation.  As a general rule, it probably wouldn't do much.  I can't rule out interactions between CoQ10 and fullerenes.  It's conceivable that it's participating in electron transport in a way that makes the ETC more efficient.

[Kalliste]

This might be related to C60-OO animals being tumor-free.
 

(-)-Oleocanthal rapidly and selectively induces cancer cell death via lysosomal membrane permeabilization (LMP)

(-)-Oleocanthal (OC), a phenolic compound in extra virgin olive oil (EVOO), has been implicated in the health benefits associated with diets rich in EVOO. We investigated the effect of OC on human cancer cell lines in culture. Amazingly, OC induced cell death in all cancer cells examined – as rapidly as 30 minutes after treatment in the absence of serum. OC treatment of non-transformed cells suppressed proliferation, but did not cause cell death. OC induced both primary necrotic and apoptotic cell death via induction of lysosomal membrane permeabilization (LMP). We provide evidence that OC promotes LMP by inhibiting acid sphingomyelinase (ASM) activity, which destabilizes the interaction between proteins necessary for lysosomal membrane stability. The data presented here indicates that cancer cells having fragile lysosomal membranes – as compared to non-cancerous cells – are susceptible to lysosomotropic agent-induced cell death. Therefore, targeting lysosomal membrane stabiltiy represents a novel approach to induce cancer-specific cell death.

 

http://www.tandfonli...56.2015.1006077

[niner]

This might be related to C60-OO animals being tumor-free.
 

(-)-Oleocanthal rapidly and selectively induces cancer cell death via lysosomal membrane permeabilization (LMP)

http://www.tandfonli...56.2015.1006077

 

Whoever rated this "ill informed" is a little trigger-happy, imho.  This is an interesting result as far as heavy users of olive oil (such as myself, and a lot of us) are concerned, but I don't think that Baati's rats got enough olive oil for polyphenols to be a significant factor.  I think that anti-ROS effects are the best candidate for the lack of tumors, based on results like this report by Porporato et al. (which gets my vote for most important paper of the year) as well as this abstract.

[Turnbuckle]

 

This might be related to C60-OO animals being tumor-free.
 

(-)-Oleocanthal rapidly and selectively induces cancer cell death via lysosomal membrane permeabilization (LMP)

http://www.tandfonli...56.2015.1006077

 

Whoever rated this "ill informed" is a little trigger-happy, imho.  This is an interesting result as far as heavy users of olive oil (such as myself, and a lot of us) are concerned, but I don't think that Baati's rats got enough olive oil for polyphenols to be a significant factor.  I think that anti-ROS effects are the best candidate for the lack of tumors, based on results like this report by Porporato et al. (which gets my vote for most important paper of the year) as well as this abstract.

 

 

 

If  mitoTEMPO has this effect on cancer, then so should CoQ10.

 

William Faloon at LEF--

 

For example, a recent melanoma study compared the effects of administering alpha interferon with or without daily CoQ10 (400 mg). There was an astounding 10-fold lower risk of metastasis in the CoQ10-supplemented group! This effect was even more pronounced for those with more advanced melanoma, where CoQ10-supplemented patients were 13 times less likely to develop metastasis. Alpha interferon is an immune boosting drug that can induce side effects so severe that patients have to discontinue it. In this study, only 22% of CoQ10-supplemented patients developed side effects compared to 82% not taking supplemental CoQ10. 

 

Edited by Turnbuckle, 21 February 2015 - 02:34 PM.

[pone11]

 

This might be related to C60-OO animals being tumor-free.
 

(-)-Oleocanthal rapidly and selectively induces cancer cell death via lysosomal membrane permeabilization (LMP)

http://www.tandfonli...56.2015.1006077

 

Whoever rated this "ill informed" is a little trigger-happy, imho.  This is an interesting result as far as heavy users of olive oil (such as myself, and a lot of us) are concerned, but I don't think that Baati's rats got enough olive oil for polyphenols to be a significant factor.  I think that anti-ROS effects are the best candidate for the lack of tumors, based on results like this report by Porporato et al. (which gets my vote for most important paper of the year) as well as this abstract.

 

 

Do you happen to know the mechanism of action of MitoTempo, the SOD mimetic they used in the study you are calling out?   Assuming the mechanism is different, it would be so interesting to see a mouse study where they combine MitoQ, MitoTempo, and C60+OO together to see if they have synergistic effects on superoxide.

 

I had bookmarked the same study previously, but read it in more detail now and picked up the fact that "In the ETC, complexes I and III are the main sources of electron leakage, hence of superoxide (Muller et al., 2004)."   That suggests that MitoQ might be an incredibly important supplement to deal with increased superoxide levels as we age, since MitoQ is CoQ10, which plays its antioxidant functions between electron transport chain (ETC) complexes 1 and 3.

 

This Cell study you cite contains so much original science and integration of ideas that I would have to agree it is really special.   Let's put these guys on the C60 story.

Edited by pone11, 22 February 2015 - 05:58 AM.

[niner]

Do you happen to know the mechanism of action of MitoTempo, the SOD mimetic they used in the study you are calling out?   Assuming the mechanism is different, it would be so interesting to see a mouse study where they combine MitoQ, MitoTempo, and C60+OO together to see if they have synergistic effects on superoxide.

 

TEMPO is a nitroxide (a hindered piperidine oxide, in this case) and these can react with superoxide to produce a hydroxylamine plus oxygen.  Another superoxide, along with protons from water can then react with the hydroxylamine, oxidizing it back to TEMPO and producing H2O2.   I suspect that MitoQ, MitoTEMPO, and c60oo all do essentially the same thing with respect to superoxide, so my guess is that there probably isn't going to be a synergy.  It would be really cool if someone did a heads up comparison of the three.

[pone11]

 

Do you happen to know the mechanism of action of MitoTempo, the SOD mimetic they used in the study you are calling out?   Assuming the mechanism is different, it would be so interesting to see a mouse study where they combine MitoQ, MitoTempo, and C60+OO together to see if they have synergistic effects on superoxide.

 

TEMPO is a nitroxide (a hindered piperidine oxide, in this case) and these can react with superoxide to produce a hydroxylamine plus oxygen.  Another superoxide, along with protons from water can then react with the hydroxylamine, oxidizing it back to TEMPO and producing H2O2.   I suspect that MitoQ, MitoTEMPO, and c60oo all do essentially the same thing with respect to superoxide, so my guess is that there probably isn't going to be a synergy.  It would be really cool if someone did a heads up comparison of the three.

 

 

There are so many good antioxidants showing up now that attack superoxide.   What about peroxy nitrite?  Are there any new antioxidants that address that?  

 

I've read that many people have the CBS upregulation genetic defect (I do for sure, as shown by my 23 and me testing).   CBS upregulation tends to drain BH4 so that not enough is available in the urea cycle to generate nitric oxide.   The formation of nitric oxide requires two BH4 molecules. With insufficient BH4, the body will instead produce peroxy nitrite (with one BH4 molecule), or super oxide (if no BH4 is available).

 

As people age you do see nitric oxide levels go very low.   BH4 depletion might be one of the mechanisms that increases levels of oxidative stress, but it is not just superoxide we need to worry about.

Edited by pone11, 23 February 2015 - 05:09 AM.

[niner]

There are so many good antioxidants showing up now that attack superoxide.   What about peroxy nitrite?  Are there any new antioxidants that address that?  
 
I've read that many people have the CBS upregulation genetic defect (I do for sure, as shown by my 23 and me testing).   CBS upregulation tends to drain BH4 so that not enough is available in the urea cycle to generate nitric oxide.   The formation of nitric oxide requires two BH4 molecules. With insufficient BH4, the body will instead produce peroxy nitrite (with one BH4 molecule), or super oxide (if no BH4 is available).
 
As people age you do see nitric oxide levels go very low.   BH4 depletion might be one of the mechanisms that increases levels of oxidative stress, but it is not just superoxide we need to worry about.

 

Here's an example of an inhibition of peroxynitrite formation by a weird fullerene compound.  It may or may not be relevant to dealing with pre-formed peroxynitrite, but that may not matter all that much, since the predominant pathway to O=NOO- is through the reaction between superoxide and NO.  Note that peroxynitrite is not a radical, but it can form radicals by reacting with various small molecules.  It's best not to have it around in the first place, and effective trapping of superoxide is likely to do a lot to reduce its formation.  That's probably what's happening in this paper. 
 

Hypertens Res. 2008 Jan;31(1):141-51. doi: 10.1291/hypres.31.141.
A water-soluble fullerene vesicle alleviates angiotensin II-induced oxidative stress in human umbilical venous endothelial cells.
Maeda R¹, Noiri E, Isobe H, Homma T, Tanaka T, Negishi K, Doi K, Fujita T, Nakamura E.

¹Center for NanoBio Integration, The University of Tokyo, Japan.

A water-soluble fullerene vesicle based on the Buckminsterfullerene molecule (Ph(5)C(60)K, denoted as PhK) was explored to determine its effects on anti-oxidation of human umbilical endothelial cells (HUVEC) exposed to exogenous and endogenous reactive oxygen species (ROS). Hydrogen peroxide 0.05-0.25 mmol/L remarkably reduced the cellular viability of HUVEC. This reduction in viability was markedly improved when PhK 0.01-1 micromol/L was added simultaneously to the culture medium. The reduction of viability in HUVEC induced by angiotensin II (AII) 10(-9) to 10(-7) mol/L was improved by pretreatment with PhK 0.1 or 10 micromol/L 12 h before AII stimulation. The ROS indicator CM-H(2)DCFDA demonstrated the efficacy of PhK 1 or 10 micromol/L in decreasing AII-induced ROS production to the level induced by the AII receptor blocker RNH-6470 20 micromol/L. The AII-induced peroxynitrite formation, as gauged using hydroxyphenyl fluorescein as a probe, was alleviated significantly by either pretreatment with PhK 0.1 or 1 micromol/L. Electron microscopy revealed intracellular localization of PhK in HUVEC after 12 h incubation. The PhK decreased the AII-induced apoptosis and lipid peroxidation processes as revealed by hexanoyl-lysine adduct formation. These observations show that the PhK water-soluble fullerene vesicle is promising as a compound controlling not only exogenous ROS, but also endogenous AII-mediated pathophysiological conditions.

PMID: 18360029

 

[Kalliste]

Some are trying to use various fullerene-compounds to develop anti-viral drugs. I'm not qualified to understand much of this work since it's pretty "theory-heavy" in some ways. I think it's an interesting subject in any way. Various C60-derivatives seems to have an anti-viral potential.

Since viral infections play a part in our aging this might be important. I suspect there are many "low level" viral infections that are unknown right now but will be explored in the future.

Maybe C60 acts to block some viral infections or slow them down in some other ways? Many viral infections also cause damage by producing ROS...

 

 

The main mechanism of anti-HIV activity of fullerene

derivatives is based on the occupation of hydrophobic vital

site of HIV-RT enzyme with fullerene core and preventing its

biological activity in proliferation of virus genome. Fullerenes

have very low binding affinity within the enzyme. This problem

is solved by addition of functional groups to isolated

fullerenes [9]. The binding affinity of fullerene derivatives is

referred to the ability of the functional groups to form hydrogen

bonds with adjacent polar groups in the enzyme, and

hydrophobic interaction of fullerene cage with nonpolar binding

sites of enzyme cavity [11, 13, 36, 37]. The more deformation

of electron density in HIV inhibitors results in more

capability of binding to the HIVenzymes.

http://link.springer...0894-014-2486-z

[Kalliste]

Another study on clusters. They seem somewhat harmless.

Bull Exp Biol Med. 2015 Feb 26.

Analysis of Toxicity Biomarkers of Fullerene C60 Nanoparticles by Confocal Fluorescent Microscopy.

Shipelin VA1, Smirnova TA, Gmoshinskii IV, Tutelyan VA.

Author information

Abstract

The methods of laser confocal microscopy were employed to study the changes in rat target organs (iliac mucosa and liver) provoked by peroral administration of dispersion of nanosized (31 nm) multimolecular fullerene C60 particles in doses of 0.1, 1.0, and 10 mg/kg body weight over 92 days. The micropreparations were selectively stained with fluorescent dyes to mark the cell nuclei (DAPI), actin microfilaments (fluorescently labeled phalloidin), and the membrane proteins CD106, CD31, and claudins in tight junctions (fluorescently labeled monoclonal antibodies). In rats treated with fullerene in the examined doses, the iliac mucosa demonstrated normal morphology of the villi. There were no signs of inflammation and no alterations in the actin fi laments of cytoskeleton and in enterocytic tight junctions. The count of CD106+ and CD31+ cells did not change. The highest examined doses of fullerene (1 and 10 mg/kg body weight) increased population and modified distribution of hepatic CD106+ cells. They also resulted in accumulation of cytoplasmic granules presumably identified as Kupffer macrophages without any signs of visible inflammation or necrotic areas. This phenomenon can reflect the early stages of toxic reaction being a sensitive bioindicator of the damage produced by administered fullerene C60 in the hepatic tissue.

http://www.ncbi.nlm....pubmed/25711666

[pone11]

I'm seeing some buzz in popular media today about a new study that shows graphene neutralizes cancer stem cells.  I'm not sure if this implies action against a tumor developing in the first place, or if it only attacks the metastasis.   Here is popular press reference:

http://www.kurzweila...ncer-stem-cells

 

Here is full text:

http://www.impactjou...348&path[]=6631

 

Maybe others here could relate difference between C60 as people are now taking it and a graphene?

 

I assume this was all in vitro, so it's a long way away from humans getting this in vivo.

 

Here is abstract of study:

 

"Tumor-initiating cells (TICs), a.k.a. cancer stem cells (CSCs), are difficult to eradicate with conventional approaches to cancer treatment, such as chemo-therapy and radiation. As a consequence, the survival of residual CSCs is thought to drive the onset of tumor recurrence, distant metastasis, and drug-resistance, which is a significant clinical problem for the effective treatment of cancer. Thus, novel approaches to cancer therapy are needed urgently, to address this clinical need. Towards this end, here we have investigated the therapeutic potential of graphene oxide to target cancer stem cells. Graphene and its derivatives are well-known, relatively inert and potentially non-toxic nano-materials that form stable dispersions in a variety of solvents. Here, we show that graphene oxide (of both big and small flake sizes) can be used to selectively inhibit the proliferative expansion of cancer stem cells, across multiple tumor types. For this purpose, we employed the tumor-sphere assay, which functionally measures the clonal expansion of single cancer stem cells under anchorage-independent conditions. More specifically, we show that graphene oxide effectively inhibits tumor-sphere formation in multiple cell lines, across 6 different cancer types, including breast, ovarian, prostate, lung and pancreatic cancers, as well as glioblastoma (brain). In striking contrast, graphene oxide is non-toxic for “bulk” cancer cells (non-stem) and normal fibroblasts. Mechanistically, we present evidence that GO exerts its striking effects on CSCs by inhibiting several key signal transduction pathways (WNT, Notch and STAT-signaling) and thereby inducing CSC differentiation. Thus, graphene oxide may be an effective non-toxic therapeutic strategy for the eradication of cancer stem cells, via differentiation-based nano-therapy."

Edited by pone11, 28 February 2015 - 12:05 AM.

[Logic]

pone11: Supplementing Catalase:
http://www.longecity...alase/?p=716303

[Kalliste]

I'm seeing some buzz in popular media today about a new study that shows graphene neutralizes cancer stem cells.  I'm not sure if this implies action against a tumor developing in the first place, or if it only attacks the metastasis.   Here is popular press reference:

http://www.kurzweila...ncer-stem-cells

 

Here is full text:

http://www.impactjou...348&path[]=6631

 

Maybe others here could relate difference between C60 as people are now taking it and a graphene?

 

I assume this was all in vitro, so it's a long way away from humans getting this in vivo.

 

Here is abstract of study:

 

"Tumor-initiating cells (TICs), a.k.a. cancer stem cells (CSCs), are difficult to eradicate with conventional approaches to cancer treatment, such as chemo-therapy and radiation. As a consequence, the survival of residual CSCs is thought to drive the onset of tumor recurrence, distant metastasis, and drug-resistance, which is a significant clinical problem for the effective treatment of cancer. Thus, novel approaches to cancer therapy are needed urgently, to address this clinical need. Towards this end, here we have investigated the therapeutic potential of graphene oxide to target cancer stem cells. Graphene and its derivatives are well-known, relatively inert and potentially non-toxic nano-materials that form stable dispersions in a variety of solvents. Here, we show that graphene oxide (of both big and small flake sizes) can be used to selectively inhibit the proliferative expansion of cancer stem cells, across multiple tumor types. For this purpose, we employed the tumor-sphere assay, which functionally measures the clonal expansion of single cancer stem cells under anchorage-independent conditions. More specifically, we show that graphene oxide effectively inhibits tumor-sphere formation in multiple cell lines, across 6 different cancer types, including breast, ovarian, prostate, lung and pancreatic cancers, as well as glioblastoma (brain). In striking contrast, graphene oxide is non-toxic for “bulk” cancer cells (non-stem) and normal fibroblasts. Mechanistically, we present evidence that GO exerts its striking effects on CSCs by inhibiting several key signal transduction pathways (WNT, Notch and STAT-signaling) and thereby inducing CSC differentiation. Thus, graphene oxide may be an effective non-toxic therapeutic strategy for the eradication of cancer stem cells, via differentiation-based nano-therapy."

 

This is a good opportunity to alert others about Fullerenes in the various commentary-fields of the internet. Good to see that big clusters of carbon particles seems to do something good and not being exclusively toxic in case C60 causes such aggregates to form.

 

OT:

There was also the use of silicon nanoparticles to increase strength of bones the other day. And the PEG-HCC I posted here which was also big clusters doing something funny.

[pone11]

Well this is a very interesting paper that I found today. It is posted in the Biosciencenews section, however I wanted to bring it here because it seems this might be related to C60.

 

 

Significance

Mechanistic studies of nontoxic hydrophilic carbon cluster nanoparticles show that they are able to accomplish the direct conversion of superoxide to dioxygen and hydrogen peroxide. This is accomplished faster than in most single-active-site enzymes, and it is precisely what dioxygen-deficient tissue needs in the face of injury where reactive oxygen species, particularly superoxide, overwhelm the natural enzymes required to remove superoxide. We confirm here that the hydrophilic carbon clusters are unreactive toward nitric oxide radical, which is a potent vasodilator that also has an important role in neurotransmission and cytoprotection. The mechanistic results help to explain the preclinical efficacy of these carbon nanoparticles in mitigating the deleterious effects of superoxide on traumatized tissue.

Abstract

Many diseases are associated with oxidative stress, which occurs when the production of reactive oxygen species (ROS) overwhelms the scavenging ability of an organism. Here, we evaluated the carbon nanoparticle antioxidant properties of poly(ethylene glycolated) hydrophilic carbon clusters (PEG-HCCs) by electron paramagnetic resonance (EPR) spectroscopy, oxygen electrode, and spectrophotometric assays. These carbon nanoparticles have 1 equivalent of stable radical and showed superoxide (O₂^•−) dismutase-like properties yet were inert to nitric oxide (NO^•) as well as peroxynitrite (ONOO⁻). Thus, PEG-HCCs can act as selective antioxidants that do not require regeneration by enzymes. Our steady-state kinetic assay using KO₂ and direct freeze-trap EPR to follow its decay removed the rate-limiting substrate provision, thus enabling determination of the remarkable intrinsic turnover numbers of O₂^•− to O₂ by PEG-HCCs at >20,000 s⁻¹. The major products of this catalytic turnover are O₂ and H₂O₂, making the PEG-HCCs a biomimetic superoxide dismutase.

 

http://www.pnas.org/...047112.abstract

 

Here is full text for the study @Comicalstorm found:

http://www.pnas.org....12/8/2343.short

 

Can someone explain to us what is the difference between the hydrophilic carbon clusters (HCC) in this study and C60?

 

In the study, the HCC acts like SOD and converts superoxide to O2 and hydrogen peroxide (H2O2).   Others have posted in this thread a link to this Biomaterials study on how C60 quelches free radicals:

http://www.howard.ed...g fullerene.pdf

 

This study on C60 says that it can scavenge many kinds of free radicals including superoxide, and that it can also scavenge many toxic byproducts of H202.   But what I am not clear on from this study is what does C60 convert superoxide to?  What is the actual chemical transformation?   The study almost makes it sound like the superoxide gets "stuck" to the C60 but clearly it cannot just stay there forever?

 

Niner, do you see anything in the Biomaterials study that explains what the transformation is?

 

What do others make of the fact that both of these studies are using hydrophilic forms of C60?   The form we use in C60+OO are hydrophobic?

 

Edited by pone11, 28 February 2015 - 07:48 PM.

[Kalliste]

I wonder if you can buy gado- linium endohedral metallofullerenol (Gd@C82(OH)22)?

Does anyone know the nm size of Lipofullerenes?

" However, little
is known about the effects of nanoparticle size on the antioxidant and radical quenching activities of fullerenes. We determined that
nanoparticles of Gd@C82(OH)22, C82(OH)22, and C60(C(COOH)2)22 differed in average size (78 nm, 123 nm and 170 nm, respectively). A suspension of larger nanoparticles would provide smaller total surface area for interaction with the biological environment, namely, provide less reactive sites for the ROS, thus reducing the efficiency of scavenging reactive species. This factor may contribute to the relative efficiencies (i.e., Gd@C82(OH)22 -
C82(OH)22 >C60(C(COOH)2)2) we note in their cytoprotection, radical scavenging and inhibition of lipid peroxidation. In addition, size may influence the distribution of nanoparticles in cells and in tissues."

Edited by Cosmicalstorm, 01 March 2015 - 01:26 PM.

[Kalliste]

Slightly off topic as it concerns C82 but interesting none the less. It can interfere directly with cancer stem cells... These carbon molecules seem like they can do a lot.
 

 

The contemporary use of nanomedicines for cancer treatment has been largely limited to serving as carriers for existing therapeutic agents. Here, we provide definitive evidence that, the metallofullerenol nanomaterial Gd@C82(OH)22, while essentially not toxic to normal mammary epithelial cells, possesses intrinsic inhibitory activity against triple-negative breast cancer cells. Gd@C82(OH)22 blocks epithelial-to-mesenchymal transition with resultant efficient elimination of breast cancer stem cells (CSCs) resulting in abrogation of tumour initiation and metastasis. In normoxic conditions, Gd@C82(OH)22 mediates these effects by blocking TGF-β signalling. Moreover, under hypoxic conditions found in the tumour microenvironment, cellular uptake of Gd@C82(OH)22 is facilitated where it functions as a bi-potent inhibitor of HIF-1α and TGF-β activities, enhancing CSC elimination. These studies indicate that nanomaterials can be engineered to directly target CSCs. Thus, Gd-metallofullerenol is identified as a kind of non-toxic CSC specific inhibitors with significant therapeutic potential.

 

http://www.ncbi.nlm....pubmed/25612916

http://www.nature.co...ncomms6988.html

Edited by Cosmicalstorm, 01 March 2015 - 05:03 PM.

[pone11]

I wonder if you can buy gado- linium endohedral metallofullerenol (Gd@C82(OH)22)?

Does anyone know the nm size of Lipofullerenes?

" However, little
is known about the effects of nanoparticle size on the antioxidant and radical quenching activities of fullerenes. We determined that
nanoparticles of Gd@C82(OH)22, C82(OH)22, and C60(C(COOH)2)22 differed in average size (78 nm, 123 nm and 170 nm, respectively). A suspension of larger nanoparticles would provide smaller total surface area for interaction with the biological environment, namely, provide less reactive sites for the ROS, thus reducing the efficiency of scavenging reactive species. This factor may contribute to the relative efficiencies (i.e., Gd@C82(OH)22 -
C82(OH)22 >C60(C(COOH)2)2) we note in their cytoprotection, radical scavenging and inhibition of lipid peroxidation. In addition, size may influence the distribution of nanoparticles in cells and in tissues."

 

What is the experiment you are proposing to do?   Gadolinium is pretty toxic stuff.   Why would you want to bother with it?   They chelate gadolinium and use that as the contrast material for MRI, but it is very controversial.  In some people the chelate disassociates and the remaining gadolinium damages the kidneys:

http://www.ncbi.nlm....les/PMC3552562/

 

If I remember that study with fullerenes and Gadolinium correctly, weren't they encapsulating the gadolinium inside of a carbon cage or something like this?   It's not an application that would really apply to someone taking C60?

Edited by pone11, 01 March 2015 - 06:54 PM.

[pone11]

Slightly off topic as it concerns C82 but interesting none the less. It can interfere directly with cancer stem cells... These carbon molecules seem like they can do a lot.
 

 

The contemporary use of nanomedicines for cancer treatment has been largely limited to serving as carriers for existing therapeutic agents. Here, we provide definitive evidence that, the metallofullerenol nanomaterial Gd@C82(OH)22, while essentially not toxic to normal mammary epithelial cells, possesses intrinsic inhibitory activity against triple-negative breast cancer cells. Gd@C82(OH)22 blocks epithelial-to-mesenchymal transition with resultant efficient elimination of breast cancer stem cells (CSCs) resulting in abrogation of tumour initiation and metastasis. In normoxic conditions, Gd@C82(OH)22 mediates these effects by blocking TGF-β signalling. Moreover, under hypoxic conditions found in the tumour microenvironment, cellular uptake of Gd@C82(OH)22 is facilitated where it functions as a bi-potent inhibitor of HIF-1α and TGF-β activities, enhancing CSC elimination. These studies indicate that nanomaterials can be engineered to directly target CSCs. Thus, Gd-metallofullerenol is identified as a kind of non-toxic CSC specific inhibitors with significant therapeutic potential.

 

http://www.ncbi.nlm....pubmed/25612916

http://www.nature.co...ncomms6988.html

 

I would not accept their claim that gadolinium inside of C82 is "essentially non toxic".   Maybe yes and maybe not and probably requires a bunch of studies to verify that.

 

What's interesting in that study is that C60 had no effect on stopping tumors but the gadolinium inside C82 did.   They keep talking about an EMT phenotype, but did you pick up what is the proposed mechanism for the result they say?   Is it C82, or is it something about gadolinium?   It all seems to raise more questions than it answers.

[niner]

Here is full text for the study @Comicalstorm found:
http://www.pnas.org....12/8/2343.short
 
Can someone explain to us what is the difference between the hydrophilic carbon clusters (HCC) in this study and C60?
 
In the study, the HCC acts like SOD and converts superoxide to O2 and hydrogen peroxide (H2O2).   Others have posted in this thread a link to this Biomaterials study on how C60 quelches free radicals:
http://www.howard.ed...g fullerene.pdf
 
This study on C60 says that it can scavenge many kinds of free radicals including superoxide, and that it can also scavenge many toxic byproducts of H202.   But what I am not clear on from this study is what does C60 convert superoxide to?  What is the actual chemical transformation?   The study almost makes it sound like the superoxide gets "stuck" to the C60 but clearly it cannot just stay there forever?
 
Niner, do you see anything in the Biomaterials study that explains what the transformation is?
 
What do others make of the fact that both of these studies are using hydrophilic forms of C60?   The form we use in C60+OO are hydrophobic?

 
The hydrophilic carbon clusters are extended structures, much larger than c60; they estimate 2-5000 sp2 carbon atoms.  They are solubilized by the attachment of some number of polyethylene glycol chains.  It's a relatively non-specific structure, while c60oo is uniformly c60 in single-molecule form, attached to the fatty acid chains of a triglyceride initially, and to a single fatty acid after digestion of the trig.   It looks like all of the various forms of extended aromatic carbon systems will dismutate superoxide to some degree or another.   The products of this are oxygen and H2O2.
 
The biomaterials paper is looking at aggregated particles, despite the fact that c60(OH)22 should be soluble. Maybe it dissolved after the imaging step?  odd.  They were mainly interested in characterizing the radical quenching potency of three different fullerenes against four different types of radicals, including a nitrogen-centered radical.  They found that the quenching ability was Gd@C82(OH)22 > fullerol > bis-malonate.  It's not clear to me how all these would compare to a molecular (non-aggregated) version of the same things, or to c60-fatty acid adduct.
 
They describe the superoxide dismutase mechanism by reference to Ali et al.:
 

Ali et al. have demonstrated that derivatizing a C60 fullerene with tris-malonic acid results in electron deficient areas on the fullerene’s surface which facilitates binding of superoxide.[38] Binding of a second superoxide to an adjacent electron deficient area results in destruction of superoxide, production of H2O2, and regeneration of the fullerene in a reaction similar to that catalyzed by superoxide dismutase.

Ref 38 is work from Laura Dugan's lab.  The superoxide is definitely not sticking, at least not long term.  This reaction is catalytic, with oxygen and peroxide being released.  On the other hand, they say that hydroxyl radical will form an adduct with the fullerene.  If this is the case, then over time c60 in the body might be slowly hydroxylated.  We know, however, that hydroxyfullerenes are still effective as radical quenchers.

Edited by niner, 01 March 2015 - 09:32 PM.