poolboy, on 02 May 2012 - 10:01 PM, said:
One of the studies I have seen said that 25mg taken orally turned into 2 μM in humans. I don't know if it is linear in absorption, but if it is you would probably reach 25 μM by taking about 312 mg. Of course it would also depend on how much you weigh, too. So 250-500 mg depending on if you are a small or large person.
That sounds like buccal dosing from an ethanol solution. You would never get that blood level from swallowing that amount of resveratrol. This dosing method was discussed here
maxwatt, on 03 May 2012 - 04:39 PM, said:
The absorption of oral resveratrol is linear up to 1 gram dose, and falls off. Blood levels are in nano grams. I think we have nothing to worry about.
"Peak plasma levels of resveratrol at the highest dose were 539
F 384 ng/mL (2.4 Mmol/L, mean F SD; n = 10), which occurred
1.5 h post-dose."*
The highest dose was 5 grams. I doubt if one can reach a blood serum level sufficient to show the in vitro effects in the OP's cited study.
I agree. This is the problem with in vitro experiments. More often than not, they are using doses that are impossible to obtain in vivo. The reason for these experiments is to figure out what's going on at a molecular level; they would normally be followed up with animal experiments that look at the bioavailability of the substance.
The non-linearity of resveratrol absorption is interesting. It actually becomes more
bioavailable as the dose is increased, probably due to the swamping of one or more of the systems that normally prevent it from getting through.
bixbyte, on 04 May 2012 - 03:45 AM, said:
What if I supplemented with a 50-100 milligram capsule of 99% Res every hour could I sustain a plasma somehow to continue my Sirtuin gene but not invoke the ?AMP pathway?
Nope. Particularly not in a capsule. You could get higher blood levels if you did repeated buccal dosing from an ethanol solution, but you might be a little bit drunk all the time too... Even at that, it's pretty hard to know what's going on at the level of gene activation.
CaptainFuture, on 04 May 2012 - 08:08 AM, said:
so the whole approach seems more like gambling as long as we cannot test for the right values in humans..
But we can
test for blood levels in humans; we do this all the time. Maxwatt posted a paper above where they did just that. In the early days of resveratrol, one of our members had his own blood drawn after a dose of resveratrol, and analyzed it himself, as he had access to a lab with a liquid chromatograph.