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Still, Burant and others caution that it's too soon to tell how well the drug will work in humans, whose metabolism drastically differs from that of rodents. Sirtris is also testing a resveratrol-like compound in clinical trials for treating diabetes, with initial results expected later this year or early next year.
Both Sinclair and Westphal have high hopes for the drugs, in part because they appear to mimic the effects of caloric restriction, which has been shown to delay or slow the progression of a variety of age-related diseases. So the novel SIRT1 activators might have the potential to treat illnesses ranging from Alzheimer's disease to heart disease to cancer. "The big news here is that maybe all big diseases of aging fall into the same category and can be treated with sirtuin activators," says Leonard Guarente, an MIT biologist whose lab discovered the first sirtuin gene. Guarente recently joined Sirtris's advisory board.
Initial studies suggest that activating SIRT1 can slow neurodegeneration, and tests of the compounds' impact on animal models of different diseases are ongoing.
However, many questions remain to be answered. While Sinclair and Guarente argue that the new findings support the idea that sirtuins lie at the heart of caloric restriction's health and longevity benefits, not everyone agrees. And the issue that has garnered the most media attention--whether or not such compounds will provide a molecular fountain of youth--is still unclear. While the diabetes research is promising, says Burant, "the life-extension part of this story is still incomplete."
In fact, that question may remain open for a few more years. Sinclair's team is testing the compounds' effect on life span, "but we may know if they can treat a disease in humans before we know if mice live longer," he says.
Rapamycin, an immunosuppressant, enables elderly mice to live longer.
A new drug proves effective in fighting obesity and related diseases while increasing stamina in mice.
Guest (bioinvestigator)
Tests of resveratrol supplements
Consumer Lab, an independent dietary supplement evaluation organization, published a report on 13 November 2007 on the popular resveratrol supplements. They stated that there exists a wide range in quality, dose, and price among products evaluated. The actual amount of resveratrol contained in the capsules range from 2.2mg for Revatrol, which claimed to have 400mg of "Red Wine Grape Complex", to a high of 500mg for Biotivia Transmax, which is consistent with the amount claimed on the product's label. Prices per 100mg of resveratrol ranged from less than $.30 for products made by Biotivia, Jarrow, and Country life, to a high of $45.27 for the Revatrol brand. None of the products tested were found to have significant levels of heavy metals or other contaminants
am not sure about chocolate but a friend of mine told me that he had started taking resveratrol based on a doctors suggestion about six weeks ago. My friend was experiencing chronic fatigue
and was having trouble sleeping. I asked him how it was working out and he said that he was taking a type of resveratrol called biotivia transmax and that after two weeks the results were subtle but undeniable. He said that he had more energy during the day, was more alert throughout the day and was sleeping less but waking up more refreshed. So based on his experience I decided to give it a try. I have had similiar results after just one week. It is only recently that I have heard about it anti-aging benefits.
There is something to this resveratrol, I have no idea if I will live longer but I can tell you that I am living better now.
The thing that Sirtris Pharmaceuticals is not advertising, as they have put a lot of research into compounds that activate sirtuins, is that sirtuin blockers maybe far more life prolonging that sirtuin enhancers. At least that’s what Valter Longo found in yeast in 2005. Putting in an extra copy of the SIR2 gene increased the lifespan of yeast by 30% but knocking it out altogether increased it by 600%.
If we achieved the same feat in humans our lifespans would be about 5 centuries!
Problems with receptor Blockers
Competitively blocking a receptor with a natural substance and completely blocking it are unfortunately two very different things. Witness the recent problems with Avandia. There are many natural substances that competitively block the PPAR site without adverse effects but when completely blocked with Avandia there were significant and serious side effects. Unfortunately these did not come to light until the drug was already in wide spread use. This news is exciting but there is still the need to be cautious
Manufacturing in the United States is in trouble. That's bad news not just for the country's economy but for the future of innovation.
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jsstubbs
2 Comments
Resveratrol
Your artilce is not accurate in its statement that resvertrol is not available in pill form in the amounts given to mice in the Harvard study released about a year ago. A human could take 3 pure 500 mg pills per day to reach the equivalent amount. There is also growing evidence that resveratrol is effective in Much lower doses than this. You have to remember that if natural Resveratrol can effectively be delivered in manageable quantities,this hurts Sirtris's business model. It is in their best interest to say that Resveratrol is weak and that humans should only take their product. My guess is that the truth will come out soon; that resveratrol is effective in smaller doses than Sirtis would want you to believe.
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posttoasties
1 Comment
Re: Resveratrol
The above commenter misses the point. Resveratrol is an effective natural substance, but it does not achieve the 30% life-extension in humans that have been observed in other species.
The Sirtis compounds are NOT Resveratrol at all. They are other activators that stimulate Sirtuins to a far greater degree than Resveratrol will ever be able to achieve on its own.
The other problem with buying off-the-shelf Resveratrol is that it is a non-regulated "supplement". You don't know how much of the compound you're purchasing from any of the hippy-dippy vitamin manufacturers, no matter what the label says. Resveratrol is especially vulnerable to oxidation, so it is difficult if impossible to know if what you're buying is even bio-available.
Give me an FDA-approved Sirt1 stimulator, please! If it from Guarente's lab it will be the real deal.
Reply
jsstubbs
2 Comments
Re: Resveratrol
Sirtris compound, SRT501 is resveratrol and it has been found to effectively treat type 2 diabetes in mice - just as the novel compounds treated type 2 diabetes in mice (and which are 1000 times more powerful than resveratrol and SRT501). The question is, do humans need substances 1000 times more powerful than resveratrol/SRT501. Reseratrol/SRT501 treats diabetes in mice - what else does resveratrol/SRT501 treat?
Reply
rlindsl
30 Comments
resveratrol study dosages
200mg per kilogram in many of the studies. Doing the math for my body weight puts me at about sixteen grams to achieve similar plasma concentrations It is metabolized very quickly, in a few hours. The main contaminant in the herb source is a laxative. And it comes from China... reason to worry on several levels! very happy to hear about the new class, plan to ultramarathon with it.
Reply
MolBioGurl
1 Comment
Resveratrol
What is less known, or at least advertised, is that resveratrol does not actually increase Sirt1 activity against its natural substrate at all. It was found and published in 2005 that the observed increase in Sirt1 activity due to resveratrol was dependent on the fluorophore attached to the substrate (1). In other words, resveratrol increases Sirt1 activity only against a synthetic substrate, not against substrates generated by your cells. Thus, while resveratrol does appear to possess life prolonging properties, at least in some of the tested animals, it does not do so through Sirt1. This is something else I don't think we will find advertised on resveratrol distributor's sites. In order for Sirtris to market their other Sirt1 "stimulators" they'd best show it works on natural substrates.
1. Margie T. Borra, Brian C. Smith, and John M. Denu. "Mechanism of Human SIRT1 Activation by Resveratrol"
The Journal Of Biological Chemistry Vol. 280, No. 17, April 29, pp. 17187–17195, 2005
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