989 replies to this topic

[QuestforLife]

Odd study.

 

1.  Not 24mg twice daily.  From the study,

"Asiatic acid and asiaticoside were administered as two 6 mg or two 12 mg capsules, respectively"

 

 

Thanks, I read the study too fast and missed the part where they dosed 12mg (not 24mg) twice. Either way, I've only thus far being taking 1x120mg gotu kola tablet per day, with ~43% triterpenes (~24mg asiaticoside), so according to 'my' study I should be in the right serum range.

 

But I am a little alarmed at the much larger plasma concentrations achieved in the study you reference. If those numbers are accurate we'd need a much lower dose (see attached pic, higher curve is after repeated dosing for 6 days).

Attached Thumbnails

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Edited by QuestforLife, 16 February 2021 - 04:11 PM.

[capob]

Thanks, I read the study too fast and missed the part where they dosed 12mg (not 24mg) twice. Either way, I've only thus far being taking 1x120mg gotu kola tablet per day, with ~43% triterpenes (~24mg asiaticoside), so according to 'my' study I should be in the right serum range.

 

But I am a little alarmed at the much larger plasma concentrations achieved in the study you reference. If those numbers are accurate we'd need a much lower dose (see attached pic, higher curve is after repeated dosing for 6 days).

 

 

@:study1 [Discovery of potent telomerase activators: Unfolding new therapeutic and anti-aging perspectives]@{[mmr-20-04-3701.pdf]}

@:study2 [reference 78] @{[grimaldi1990.pdf]} Grimaldi, R., De Ponti, F., D’Angelo, L., Caravaggi, M., Guidi, G., Lecchini, S., … Crema, A. (1990). Pharmacokinetics of the total triterpenic fraction of Centella asiatica after single and multiple administrations to healthy volunteers. A new assay for asiatic acid. Journal of Ethnopharmacology, 28(2), 235–241. doi:10.1016/0378-8741(90)90033-p

@:study3 @{[rush1993.pdf]} The comparative steady-state bioavailability of the active ingredients of Madecassol

 

 

Yeah, I considered that.

 

As I mentioned

 

"I can't explain the lack of matching peaks, unless the 30mg triterpene dose in the other study had much more that contributed to the resulting asiatic acid content than ~12-15mg of asiaticoside, or, perhaps, there was something delaying the 12mg dose absorption. "

 

Well, the study (@{study2}) provides more detail:

 

"The three principal components of the TTF of C. asiatica are asiatic acid, madecassic acid and asiaticoside. Asiatic and madecassic acids together account for approximately 60% and asiaticoside for 40% of the product. "

 

So, 30mg dose of TTF is 12mg asiaticoside + ~9mg asiatic acid.  In @{Study3}, 6mg of asiatic acid spiked blook concentration to .082mcg.  If you model that, on the graph showing the 6mg asiatic acid and the 12mg asiaticoside, the removal of asiatic acid is continual, and then you combine the two results (to replicate the 30mg TTF dose), the .5mcg seen in the other study fits.  It's a bit complex as to why:

 

The trailing end of slower decrease in blood concentration of asiatic acid is probably due to, as I mentioned:

1. Asiaticoside to asiatic acid was inhibited [slower] more highly at lower concentrations of asiatocide. 

2. Slow asiaticoside to asiatic acid, particularly at the tail end, was likely also due to latent asiaticoside build up that is released over time (accumulation in fat?)

And one more I didnt mention

3. removal of asiatic acid is slower and lower concentrations

 

This would mean the max removal of asiatic acid from the blood would need to be calculated prior to build up of asiaticoside, which would be slowly transformed into asiatic acid, decreasing the decrease rate of asiatic acid.  The best we can do with the graphs is find the max decrease after the peak, which is about .22mcg/hr (@{study2}).  While, on the lower end, from @{study3}, you'd get a removal max of ~.03mcg/hr.  Expectably, removal ramps up to a maximum as asaitic acid content increases.

 

Since both lines are experiencing this asiatic acid reduction (two separate groups), after combining the lines, you have to add the removal rate to get what the combination would look like.  The pre-offset peak would be ~.140mcg/ml, at hour 3, compared to @{study1} of a .52mcg/ml peak at hour 4.  Considering an asiatic acid removal rate of between .22mcg/hr and .03mcg/hr, favoring the higher rate (since there would be higher asiatic acid content), the studies fit.

 

 

So, I will cycle back to things I've said:

1. "Looking up triterpene content in extracts, I estimate 10mg/ml on the high side [Triterpene Composition and Bioactivities of Centella asiatica](https://www.mdpi.com...9/16/2/1310/htm) - unless explicit isolation.

Assuming ~1g/ml, the standard dosage on supplemental gotu kola is presented as 1g, which fits nicely into the recommendable amount based on my numbers.""

2. Regarding your 2x [now 1x] 24mg asiaticoside dose "Regardless,  your dose is too high."

 

 

Considering that .2mcg/ml has lower, but still elevated, telomerase activity compared to .02mcg/ml, the target should be .02mcg/ml.  In reality, the .02mcg/ml could already be in the decline phase (ie, 0.01mcg/ml could have max telomerase activity), since lower was not measured.  Somwhere btween .2mcg/ml and 2mcg/ml is an unacceptable level, where telomerase activity is suppressed.  

 

And, it gets a little more complicated.

 

@{study1} 08AGTLF is 95% triterpenes (and asiatic acid) (http://www.apexbt.co...iaticoside.html), not 100% asiaticoside.  The other studies @{study2} @{study3} measure asiatic acid, not triterpene content, where as, @{study1} is ~triterpene content.

We might consider that the total blood content of asiatic acid can be used to determine the blood content of asiaticoside.  We might consider that the blood content of asiaticoside maxes out shortly after dosing, when the dose is mostly absorbed.  As such, we can consider that the asiatic acid after about, lets say, hour 2, represents a constant decrease of blood asiaticoside being transformed into asiatic acid.  As such, the area under the curve of asiatic acid (using an asiatic acid removal rate algorithm (to value the x axis time periods based on variable removal rate)), would give you the max blood concentration of asiaticoside (at hour ~0-2).  

 

If we assume 2hr peak and average .1mcg/ml asiatic acid when above .1mcg/ml blood concentration, 

 

from @{study2}

3hr rise to peak after 2hr mark (reducing at .1mcg/ml)

rise until 2hr mark assumed .1mcg/ml per hour reduction 

9hr reduction (reducing at .1mcg/ml)

 

You get, [excuse my sloppiness], ~1mcg/ml max asiaticoside concentration (ignoring the partial asiatic content of TTF) to explain the peak .5mcg/ml asiatic acid blood concentration after a 30mg TTF dose.

 

IE, I would guess that asiaticoside content will be higher initially than the peak that asiatic acid reaches. 

 

But, considering I take ~1.5mg of asiaticoside (from the 10mg triterpenes in a regular extract), and that the study indicating .02mcg/ml was on a triterpenes mix (not isolated asiaticoside) (ie, 0.02mcg/ml of triterpenes, not asiaticoside), this isn't concerning enough for me to investigate further.  All that said, I seem to be allergic to gotu kola...  (jk)

Edited by capob, 16 February 2021 - 07:38 PM.

[QuestforLife]

Thanks for the detailed analysis Capob.

Regarding the difference in telomerase activation between 0.02ug/ml and 0.2ug/ml I'd have to go back to the study again,but I don't think the difference in activation was statistically significant. So I regard anything in that 0.02-0.2ug/ml range as acceptable.

Having said that, I do regard it as suspicious that higher doses produce less activation, with 2ug/ml producing no detectable telomerase activation. And the answer may be the fact that they used a triterpene fraction containing as you say multiple compounds. It may well be that one or more of these compounds was counterproductive and the its effect became dominant at higher doses. Further studies to unpick this are required.

[QuestforLife]

Small-Molecule PAPD5 Inhibitors Restore
Telomerase Activity in Patient Stem Cells

https://www.cell.com...87?showall=true

 

 

Some may remember that a while ago I discussed upregulating the RNA component of telomerase (TERC) as a way of lengthening telomeres only in (stem) cells that already have some level of the protein component expressed (TERT).

 

 

Small-Molecule PAPD5 Inhibitors Restore Telomerase Activity in Patient Stem Cells
Genetic lesions that reduce telomerase activity inhibit stem cell replication and cause a range of incurable diseases, including dyskeratosis congenita (DC) and pulmonary fibrosis (PF). Modalities to restore telomerase in stem cells throughout the body remain unclear. Here, we describe small-molecule PAPD5 inhibitors that demonstrate telomere restoration in vitro, in stem cell models, and in vivo. PAPD5 is a non-canonical polymerase that oligoadenylates and destabilizes telomerase RNA component (TERC). We identified BCH001, a specific PAPD5 inhibitor that restored telomerase activity and telomere length in DC patient induced pluripotent stem cells. When human blood stem cells engineered to carry DC-causing PARN mutations were xenotransplanted into immunodeficient mice, oral treatment with a repurposed PAPD5 inhibitor, the dihydroquinolizinone RG7834, rescued TERC 3′ end maturation and telomere length. These findings pave the way for developing systemic telomere therapeutics to counteract stem cell exhaustion in DC, PF, and possibly other aging-related diseases.
Source: https://www.scienced...301387?via=ihub

 

 

I could not progress this further as the drug required was not affordable.
Promisingly, I recently came across this very interesting 2020 preprint paper:

 

 

 Mutual regulation between GDF11 and TET2 prevents senescence of mesenchymal stem cells

GDF11 can block MSC aging in vitro, and reverse age-dependent bone loss in vivo. The anti-aging effect of GDF11 is via activation of the Smad2/3-PI3K-AKT-mTOR pathway. Unexpectedly, GDF11 also upregulated a DNA demethylase Tet2, which served as a key mediator for GDF11 to autoregulate itself via demethylation of specific CpG sites within the GDF11 promoter. Mutation of Tet2 facilitates MSC aging by blocking GDF11 expression. Mutagenesis of Tet2-regulated CpG sites also blocks GDF11 expression, leading to MSC aging. Together, a novel mutual regulatory relationship between GDF11 and an epigenetic factor Tet2 unveiled their anti-aging roles. 
Source: https://www.biorxiv....03.30.008722v1 

 

 

The paper shows that GDF11 and TET2 regulate one another to prevent the senescence of MSCs. (Note Mesenchymal Stem Cells renew bone, fat and cartilage). This means that exogenous GDF11 boosts endogenous GDF11 production via TET2 demethylation of GDF11 promoters (Sidenote: this may indicate a synergy with AKG).
Most interestingly for the purposes of this thread, although GDF11 does not upregulate TERT, it does upregulate TERC and increase telomere length (which shows that MSCs must already have the TERT protein present). I attach the relevant Fig, see panels K, L and C.

 

 

Perhaps we might think about also upregulating TERT in addition to TERC. The following 2019 paper shows that a genetic approach to TERT upregulation in turn upregulates GFD11 and the benefits of TERT and GDF11 are better than either one alone. The paper also shows that TERT and GDF11 decline with the age of (the donor supplying) endothelial progenitor cells. The ability of EPCs to divide also falls from young to middle aged to old EPCs. Note EPCs are vital to maintain the structure and stability of the circulatory system and ward of atherosclerosis.

 

TERT assists GDF11 to rejuvenate senescent VEGFR2+/CD133+ cells in elderly patients with myocardial infarction

Growth differentiation factor 11 (GDF11) is a transforming growth factor β superfamily member with a controversial role in rejuvenating old stem cells after acute injury in the elderly population. This study aimed to evaluate the effects of telomerase reverse transcriptase (TERT) on GDF11-mediated rejuvenation of senescent late-outgrowth endothelial progenitor cells (EPCs), defined as VEGFR2+/CD133+ cells, in elderly patients with acute myocardial infarction (AMI). We compared the quantity and capabilities of VEGFR2+/CD133+ cells from old (>60 years), middle-aged (45–60 years), and young (<45 years) AMI patients. The decline in circulating count and survival of VEGFR2+/CD133+ cells with age was accompanied by decrease in their TERT and GDF11 expression levels in patients with AMI. Further, upregulation of TERT could trigger GDF11-mediated rejuvenation of old VEGFR2+/CD133+ cells by renewing their survival and angiogenic abilities through activation of canonical (Smad2/3) and noncanonical (eNOS) signaling pathways. Depletion of GDF11 or TERT caused senescence of young VEGFR2+/CD133+ cells leading to impaired vascular function and angiogenesis in vitro and in vivo, whereas adTERT and rhGDF11 rescued this senescence. TERT cooperates with GDF11 to enhance regenerative capabilities of old VEGFR2+/CD133+ cells. When combined with TERT, GDF11 may represent a potential therapeutic target for the treatment of elderly patients with MI.

Source: https://www.nature.c...-0290-1?proof=t

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[dlewis1453]

Perhaps we might think about also upregulating TERT in addition to TERC. The following 2019 paper shows that a genetic approach to TERT upregulation in turn upregulates GFD11 and the benefits of TERT and GDF11 are better than either one alone. The paper also shows that TERT and GDF11 decline with the age of (the donor supplying) endothelial progenitor cells. The ability of EPCs to divide also falls from young to middle aged to old EPCs. Note EPCs are vital to maintain the structure and stability of the circulatory system and ward of atherosclerosis.

 

Very interesting papers and analysis, thanks! This is very promising and indicates that GDF11 supplementation could play a very important role in maintaining the health of our stem cell populations. 

 

Could you elaborate a bit more on the potential synergy between AKG and GDF11? 

 

Regarding your point about upregulating TERT, I found the following paper, titled "Klotho Deficiency Accelerates Stem Cells Aging by Impairing Telomerase Activity" (https://pubmed.ncbi....h.gov/30452555/), which states:

"We found that KL deficiency diminished telomerase activity by altering the expression of TERF1 and TERT, causing impaired differentiation potential, pluripotency, cellular senescence, and apoptosis in stem cells. Telomerase activity decreased with KL-siRNA knockdown. This suggests that both KL and telomeres regulate the stem cell aging process through telomerase subunits TERF1, POT1, and TERT using the TGFβ, Insulin, and Wnt signaling. These pathways can rejuvenate stem cell populations in a CD90-dependent mechanism." 

 

Perhaps Klotho supplementation could upregulate TERT, and synergize with GDF11? Steve Perry certainly seems to think so and has recently incorporated Klotho into his protocol. 

[QuestforLife]

Very interesting papers and analysis, thanks! This is very promising and indicates that GDF11 supplementation could play a very important role in maintaining the health of our stem cell populations. 

 

Could you elaborate a bit more on the potential synergy between AKG and GDF11? 

 

Regarding your point about upregulating TERT, I found the following paper, titled "Klotho Deficiency Accelerates Stem Cells Aging by Impairing Telomerase Activity" (https://pubmed.ncbi....h.gov/30452555/), which states:

"We found that KL deficiency diminished telomerase activity by altering the expression of TERF1 and TERT, causing impaired differentiation potential, pluripotency, cellular senescence, and apoptosis in stem cells. Telomerase activity decreased with KL-siRNA knockdown. This suggests that both KL and telomeres regulate the stem cell aging process through telomerase subunits TERF1, POT1, and TERT using the TGFβ, Insulin, and Wnt signaling. These pathways can rejuvenate stem cell populations in a CD90-dependent mechanism." 

 

Perhaps Klotho supplementation could upregulate TERT, and synergize with GDF11? Steve Perry certainly seems to think so and has recently incorporated Klotho into his protocol. 

 

Thanks for the klotho paper, I'll give it a read.

 

Regarding the possible overlap between the effect of AKG and GDF11, the paper I posted shows GDF11 upregulates the demethylase TET2, which in turn demethylates two promoters of GDF11, increasing GDF11 expression. This is probably why only a small amount of GDF11 is required for rejuvenation effects, and why blood levels fall so slowly (as observed by Steve Perry and his cohort) after dosing. But back to AKG - it is an important cofactor for the demethylases to do their work, hence why it might work well with GDF11.

 

 

 

Dietary alpha‐ketoglutarate promotes beige adipogenesis and prevents obesity in middle‐aged mice

 

Previously, we reported that DNA demethylation in the Prdm16 promoter is required for beige adipogenesis. DNA methylation is mediated by ten–eleven family proteins (TET) using alpha‐ketoglutarate (AKG) as a cofactor. Here, we demonstrated that the circulatory AKG concentration was reduced in middle‐aged mice (10‐month‐old) compared with young mice (2‐month‐old). Through AKG administration replenishing the AKG pool, aged mice were associated with the lower body weight gain and fat mass, and improved glucose tolerance after challenged with high‐fat diet (HFD).

 

source: https://onlinelibrar...1111/acel.13059

 

 

 

Also see the following: 

 

 

 

Intracellular α-ketoglutarate maintains the pluripotency of embryonic stem cells

 

...naive ES cells exhibit an elevated αKG to succinate ratio that promotes histone/DNA demethylation and maintains pluripotency. Direct manipulation of the intracellular αKG/succinate ratio is sufficient to regulate multiple chromatin modifications, including H3K27me3 and ten-eleven translocation (Tet)-dependent DNA demethylation, which contribute to the regulation of pluripotency-associated gene expression. In vitro, supplementation with cell-permeable αKG directly supports ES-cell self-renewal while cell-permeable succinate promotes differentiation. This work reveals that intracellular αKG/succinate levels can contribute to the maintenance of cellular identity and have a mechanistic role in the transcriptional and epigenetic state of stem cells.

 

source: https://pubmed.ncbi....h.gov/25487152/

 

 

 

If you are interested in personal anecdotes, since I did my most recent methylation aging test in Jan 2021 (-6.6 years using AKG (and gotu kola)) I added GDF11 to my protocol and have experienced noticeable de-aging. As a 42 year old I have NEVER noticed significant improvements like this before, not with rapamycin, NMN, anything. At some point when I have enough data I will post my biomarker improvements on this thread for all to see.

[QuestforLife]

 

Regarding your point about upregulating TERT, I found the following paper, titled "Klotho Deficiency Accelerates Stem Cells Aging by Impairing Telomerase Activity" (https://pubmed.ncbi....h.gov/30452555/), which states:

"We found that KL deficiency diminished telomerase activity by altering the expression of TERF1 and TERT, causing impaired differentiation potential, pluripotency, cellular senescence, and apoptosis in stem cells. Telomerase activity decreased with KL-siRNA knockdown. This suggests that both KL and telomeres regulate the stem cell aging process through telomerase subunits TERF1, POT1, and TERT using the TGFβ, Insulin, and Wnt signaling. These pathways can rejuvenate stem cell populations in a CD90-dependent mechanism." 

 

Perhaps Klotho supplementation could upregulate TERT, and synergize with GDF11? Steve Perry certainly seems to think so and has recently incorporated Klotho into his protocol. 

 

My super quick read of the paper suggests the following: 

 

In adipose derived stem cells (ADSC), klotho knockdown increased TERF1 protein, which rolls up telomeres to protect them - but also makes access by telomerase (TERT) more difficult. I interpret this as a hunker down and protect response. You can see in Fig  7 I that Klotho -/- mutant cells had lower levels of TERT than Wild Type (WT) controls, and though cycloastragenol (CAG) increased this level it did not reach the WT level, and the beneficial effect of CAG on telomerase was greater in WT cells. 

 

So to the extent that telomere loss in stem cells is due to klotho downregulation (unknown), supplementing it should increase telomere length in those cells. A clever bet might be to combine a telomerase activator with klotho in order to make sure TERF1 isn't going to prevent TERT doing its job in extending telomeres.

 

So far we've seen good evidence for GDF11 to rejuvenate both neuronal and mesenchymal stem cells, it would be nice to see the benefits of klotho in other stem cells besides adipocyte derived types. 

 

It would also be interesting to see the effect of a powerful telomerase activator like TAM818 or Triterpene fractions on the telomere length in various stem cells, and then see how much further this could be increased by adding GDF11 (increase TERC) and Klotho (decrease TERF1).

 

We are getting closer.

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[dlewis1453]

Great! Thanks for your analysis. I'm very happy to hear that you are already noticing good results from GDF11 and am looking forward eagerly to your biomarker improvements! 

 

 

[QuestforLife]

GDF11 Rejuvenates Neural Stem Cells Via Smad2/3-PI3K-AKT-mTOR and Reverses Aged-Dependent Cognitive Decline

 

DOI: 10.2139/ssrn.3552151

Whether GDF11 is a systemic factor from young animals’ circulation that mediates the rejuvenation process in old animals during heterochronic parabiosis has been debated. We carried out transcriptomic analyses of young versus old monkey and human blood samples demonstrating negative correlations between GDF11 expression and old age, which is further confirmed by quantitative RT-PCR of GDF11 mRNA from more than 400 young and old human blood samples. Reduced GDF11 expression is also correlated with age-dependent cognitive decline. Tail vein injection of recombinant mature GDF11 into aged mice led to increased numbers of cerebral blood vessels and cerebral blood flow, enhanced neurogenesis and spatial learning. Objective and systemic transcriptomic analyses of GDF11-treated brains revealed and subsequently confirmed through biological assays, that rGDF11 regulated angiogenesis, neurogenesis, cell cycle, energy metabolism, clearance of senescent cells, as well as increased telomere length and GDF11 gene expression in neural stem cells via the Smad2/3-PI3K-AKT-mTOR pathway. 

 

This paper is from the same authors as 'Mutual regulation between GDF11 and TET2 prevents senescence of mesenchymal stem cells'; it has been reviewed but doesn't appear to be available yet as a full text. But from what I can glean, it shows similar effects from GDF11 on NSCs as reported for MSCs, namely self regulation (of the GDF11 promoter) and telomere extension in the stem cells examined. 

[OlderThanThou2]

Thanks for the klotho paper, I'll give it a read.

 

Regarding the possible overlap between the effect of AKG and GDF11, the paper I posted shows GDF11 upregulates the demethylase TET2, which in turn demethylates two promoters of GDF11, increasing GDF11 expression. This is probably why only a small amount of GDF11 is required for rejuvenation effects, and why blood levels fall so slowly (as observed by Steve Perry and his cohort) after dosing. But back to AKG - it is an important cofactor for the demethylases to do their work, hence why it might work well with GDF11.

 

 

 

 

Also see the following: 

 

 

 

 

If you are interested in personal anecdotes, since I did my most recent methylation aging test in Jan 2021 (-6.6 years using AKG (and gotu kola)) I added GDF11 to my protocol and have experienced noticeable de-aging. As a 42 year old I have NEVER noticed significant improvements like this before, not with rapamycin, NMN, anything. At some point when I have enough data I will post my biomarker improvements on this thread for all to see.

 

Which form of AKG do you take? Thanks.

[Andey]

If you are interested in personal anecdotes, since I did my most recent methylation aging test in Jan 2021 (-6.6 years using AKG (and gotu kola)) I added GDF11 to my protocol and have experienced noticeable de-aging. As a 42 year old I have NEVER noticed significant improvements like this before, not with rapamycin, NMN, anything. At some point when I have enough data I will post my biomarker improvements on this thread for all to see.

 

  Very interesting.)

  If you dont mind me asking - Where did you source GDF11? Bucky or somewhere else?

[QuestforLife]

The AKG I used is Kirkman. As far as I can tell from other reports now coming in, any form works (to reduce age as measured via methylation markers).

I got GDF11 from Bucky Labs in the US.

[Andey]

Thanks!

[OlderThanThou2]

The AKG I used is Kirkman. As far as I can tell from other reports now coming in, any form works (to reduce age as measured via methylation markers).

I got GDF11 from Bucky Labs in the US.

 

Mmh it's a mix of calcium and magnesium AKG, interesting, I think I'll buy this one next time.

 

GDF11 sounds very interesting, but probably impossible to get in France, 

 

Thank you very much.

[OlderThanThou2]

What about glutamine as a telomerase cofactor? I say cofactor rather than activator because from what I understand the residue of glucosamine Q169  seems important for telomerase to function  properly:

 

Human telomerase reverse transcriptase (hTERT) Q169 is essential for telomerase function in vitro and in vivo - PubMed (nih.gov)

 

 

Conclusions/significance: We provide the first detailed evidence regarding the biochemical and cellular roles of an evolutionarily-conserved Gln residue in higher eukaryotes. Collectively, our results indicate that Q169 is needed to maintain the hTERT N-terminus in a conformation that is necessary for optimal enzyme-primer interactions and nucleotide incorporation. We show that Q169 is critical for the structure and function of human telomerase, thereby identifying a novel residue in hTERT that may be amenable to therapeutic intervention.

 

 

It seems like glucosamine increases lifespan in mice a lot:

Glutamine supplementation significantly increases the life span of... | Download Scientific Diagram (researchgate.net)

 

I imagine probably through several means.

 

 

 

[QuestforLife]

What about glutamine as a telomerase cofactor? I say cofactor rather than activator because from what I understand the residue of glucosamine Q169  seems important for telomerase to function  properly:

 

Human telomerase reverse transcriptase (hTERT) Q169 is essential for telomerase function in vitro and in vivo - PubMed (nih.gov)

 

 

 

As far as I can tell from the 1st paper, the glutamine residue is required within the TERT protein (telomerase) in order for it to 'dock' with the telomere and extend it; no surpise that if you mess with it through mutation, then TERT becomes less effective. But it is far from clear that just eating more glutamine would increase the efficiency of telomerase.

 

Guanine is a different matter however. Mammalian telomeres are made of the repeated sequence TTAGGG, and papers have shown that it is the 1st Guanine that is rate limiting and that a greater concentration of that nucleotide (as dGTP or dGDP) speeds the process, making telomerase more efficient.

 

 

A single nucleotide incorporation step limits human telomerase repeat addition activity

https://www.embopres.../embj.201797953

Abstract
Human telomerase synthesizes telomeric DNA repeats (GGTTAG)n onto chromosome ends using a short template from its integral telomerase RNA (hTR). However, telomerase is markedly slow for processive DNA synthesis among DNA polymerases. We report here that the unique template‐embedded pause signal restricts the first nucleotide incorporation for each repeat synthesized, imparting a significantly greater KM. This slow nucleotide incorporation step drastically limits repeat addition processivity and rate under physiological conditions, which is alleviated with augmented concentrations of dGTP or dGDP, and not with dGMP nor other nucleotides. The activity stimulation by dGDP is due to nucleoside diphosphates functioning as substrates for telomerase.

 

 

Does this have any practical significance to what we eat? Maybe. I couldn't find anything specific to guanine, but more nucleotides in general seem to be of benefit in specific circumstances. Whilst the content of nucleotides in a normal diet seems sufficient ordinarily, during conditions of injury, immune response or fast growth additional nucleotide consumption is of benefit. This is what we would expect from fast proliferating tissues like the gut and immune system, which require greater telomerase activity. See [1], [2], [3].

 

[1] Effect of dietary nucleotides on small intestinal repair after diarrhoea. Histological and ultrastructural changes, https://pubmed.ncbi....ih.gov/8063220/

[2] Modulation of the immune response mediated by dietary nucleotides, https://pubmed.ncbi....h.gov/12142952/

[3] The effects of a nucleotide supplement on salivary IgA and cortisol after moderate endurance exercise, https://pubmed.ncbi....h.gov/16596104/

 

So if this has convinced you, and you want to increase the nucleotide content of what you eat, the following table may be of interest. Especially if you love anchovies!

 

[OlderThanThou2]

Would accelerating the process make much difference? How often does TERT bind to the DNA end compared to the time it takes to replicate the telomeric template? Is the DNA free most of the time anyway?

 

This study clarifies this business of Q169 somewhat:

(PDF) The N-terminus of hTERT contains a DNA-binding domain and is required for telomerase activity and cellular immortalization (researchgate.net)

 

 

 

Mutations in the N-termini of TERTs have beenidentified that impair the activity of human (55,58–63),T. thermophila (51,52,80–82) and S. cerevisiae telomerases(40,54,56,57). We identified two mutations in hTERT thatattenuated catalytic activity. We targeted hTERT-Q169for mutation based on the conservation of this residuewith TtTERT-Q168 and the position of the latter on thefloor of a putative DNA-binding groove on the surface ofthe N-terminal domain (51). Like TtTERT-Q168A,hTERT-Q169A impaired telomerase activity [(51),Figure 3]; however, unlike TtTERT-Q168A, hTERT-Q169A did not impair DNA binding [(51,52), Figure 4].This apparent discrepancy may be due to the differentassays employed for studying the DNA interaction. Jacobs et al. (51) observed that mutation of Q168reduced the crosslinking of immuno-purified RRL-TtTERT to a 20-nt-long iodouracil-substituted telomericprimer following exposure to UV light and denaturingPAGE. Romi et al. (52) observed that mutation of Q168reduced primer affinity in an assay that measured catalyticactivity of RRL-TtTERT following UV-crosslinking to a6-nt-long iodouracil-substituted telomeric primer. The for-mation of TERT:DNA crosslinks in these experimentsdepends on the proximity of iodouracil to reactiveamino acid side chains. The interaction between hTENand an 18-nt-long telomeric primer detected by nativegel EMSA was not subject to these parameters.Therefore, whereas previous studies have documentedthe involvement of TtTERT-Q168 in binding DNA,we did not find similar evidence for hTERT-Q169.Either there are species-specific differences in thefunction of this conserved residue, or a role for Q169 inbinding DNA could not be ascertained by analyzing thebehavior of the single amino acid mutant in the nativeEMSA. Thus, the phenotype of the hTERT-Q169Amutation may be similar to that of TtTERT-D94A andL174A mutations that decrease catalytic activity but notDNA binding/crosslinking (51).We also identified hTERT-Y18 as a residue (at anon-conserved position but that may lie near the end ofthe DNA-binding groove) that is required for normalcatalytic activity but not necessarily DNA binding(Figures 3 and 4, Supplementary Figure S4). Followingfrom the discussion above, it is possible that Y18 andQ169 do not contact DNA. It is also possible that bothY18 and Q169 contact DNA and can compensate, alongwith other DNA-binding residues, for the loss of any oneDNA contact in a DNA-binding assay. The loss of anyone DNA contact may yet render the enzyme incapable ofaction on a primer. The contributions of Y18 and Q169 tothe catalytic reaction cycle may be distinct, given thatmutation of each residue impaired activity to a differentdegree, but the exact contributions of these residuesremain to be determined.

 

 

This makes me wonder if there wouldn't be a way to create a mutant that binds better rather than worse than the normal TERT. Would that increase its affinity to the telomeric end and its effectiveness? I didn't understand how they created those mutants, it's too complicated for me. But perhaps there would be a way to create different residues inside the cells that would increase the binding ability.

 

Also telomerase binds to mTOR, thus increasing autophagy:

Autophagy, Cellular Aging and Age-related Human Diseases (nih.gov)

 

 

 

In addition, in multiple cell lines, such as HEK 293T, HepG2, and U-2 OS, TERT binds to and suppresses mTORC1 kinase, thereby inducing autophagy. TERT knockdown increases components of mTORC1, resulting autophagy impairment under basal and amino acid starvation conditions [89]. Autophagy contributes to inhibition of p53, which can be affected by telomere shortening. As a feedback mechanism, p53 can activate autophagy

 

Does it bind on the "port" used to bind at the end of the telomere or somewhere else? Would taking an mTORC1 inhibitor increase telomerase effectiveness by freeing it from the interaction with mTORC1?

 

Perhaps telomerase can bind to other compounds on its "port" which makes it less effective as a telomerase activator.

 

 

[JamesPaul]

QuestforLife, thank you for yet another insightful post.  It called to mind an article in Dr. David Williams' Alternatives newsletter a couple decades ago.  He related a story of an African-American man who had been a slave prior to the U.S. Civil War and was said to be 135 years old.  He was asked what he ate.  He responded, "Sardines.  I eat a lot of sardines."  Dr. Williams commented, saying that sardines, lentils, and certain other foods contain relatively large amounts of nucleotides.  Dr. Williams added that even if we consume all the amino acids needed to build nucleotides, still, people, and babies in particular, do better if they consume nucleotides.  Thanks for the table, which shows that anchovies and herring contain even more guanine than sardines.

[yucca06]

Mmh it's a mix of calcium and magnesium AKG, interesting, I think I'll buy this one next time.

 

GDF11 sounds very interesting, but probably impossible to get in France, 

 

Thank you very much.

Buckylabs now ships internationally.

 

i didn’t have really interest with gdf11 before, as it was also impossible to find even with Chinese Alibaba.com shops, but if it’s the real stuff, I could go for it. Doses seems to be quite tricky, though...

 

 

 

Edited by yucca06, 13 March 2021 - 08:13 AM.

[OlderThanThou2]

Indeed dosing sounds tricky. On the BuckyLabs website it says "Research Use Only", it's not sure they'll accept to sell it. I've seen it elsewhere on the net, like here on ebay:

GDF11 protein 10ug | eBay

 

Perhaps the seller would accept to sell it and to send it as something else than a peptide otherwise I doubt it will pass the customs.

 

Getting it from China could be a possibility. Concerning FOXO4-DRI there was concern that it wouldn't be the real deal, but GDF-11 might be easer to manufacture.

 

I have a lot of reading to do before. 

[QuestforLife]

Short and dysfunctional telomeres sensitize the kidneys to develop fibrosis
https://www.nature.c...587-021-00040-8
Abstract
Accumulation of short telomeres is a hallmark of aging. Mutations in telomerase or telomere-binding proteins lead to telomere shortening or dysfunction and are at the origin of human pathologies known as ‘telomere syndromes’, which are characterized by loss of the regenerative capacity of tissues and fibrotic pathologies. Here, we generated two mouse models of kidney fibrosis, either by combining telomerase deficiency to induce telomere shortening and a low dose of folic acid, or by conditionally deleting Trf1, a component of the shelterin telomere protective complex, from the kidneys. We find that short telomeres sensitize the kidneys to develop fibrosis in response to folic acid and exacerbate the epithelial-to-mesenchymal transition (EMT) program. Trf1 deletion in kidneys led to fibrosis and EMT activation. Our findings suggest that telomere shortening or dysfunction may contribute to pathological, age-associated renal fibrosis by influencing the EMT program.

 

Another great paper by Blasco et al., thanks to Karazantor for posting it over here

 

I’ve done a quick review of the paper and thought I’d highlight the key points here. Blasco’s team have previously established short telomere mouse models for aplastic anaemia (lack of working red blood cells) and pulmonary fibrosis (a serious fibrotic lung condition) and shown how both are related to short telomeres. Here they do the same but for chronic kidney disease, which is prevalent in the old today. They bred mice lacking telomerase for 3 generations, which gives them short telomeres, though not short enough to manifest any significant issues. They then add a toxic substance (a hefty folic acid dose) and see the effect on the kidneys of short telomere mice compared to wild type mice. As expected, the toxic treatment caused a shortening of telomeres in both mouse types, due to increased proliferation of cells. But only in the short telomere mice do problems occur - measured first by increased creatinine, BUN (Blood Urinary Nitrogen), various measures of increased fibrosis with increased collagen, fibronectin and activated fibroblasts - and later by renal dysfunction and often, death.

 

Increased cellular senescence, DNA damage and apoptosis were also seen only in the treated short telomere mice.

 

Interestingly, they were able to establish that even before treatment, the short telomere mice had higher levels of TGF-B and genes associated with the EMT. EMT is the epithelial to mesenchymal transition, whereby epithelial cells become a type of fibroblast and migrate, sometimes aggressively. The number of proliferating cells expressing EMT genes was higher in short telomere mice compared to wild type controls and increased markedly with toxic treatment in those mice with short telomeres. Upregulation of TGF-B and EMT was regulated chiefly by SMAD3; readers might remember this old friend from my days researching ROCK inhibitors. Another interesting but not surprising link given it is produced in the kidneys – Klotho was down regulated in the treated short telomere mice. There is also a link with mitochondrial function in the kidneys via NOTCH and Tfam.

 

Staying on the klotho subject for a minute, they used another mouse model to further understand the contribution of short telomeres to the renal dysfunction related to the EMT. They used genetically engineered mice in which they can delete TRF1, a shelterin protein, in all kidney cells, on treatment with a specific drug in their diet. This treatment caused many of the same changes as the short telomere mouse model treated with a toxin, including upregulation of genes associated with the EMT. I discussed the effect of Klotho downregulation back in post #427. Loss of Klotho in that case caused upregulation in TRF1, rolling up the telomere and stopping the action of telomerase. But here they are deliberating downregulating TRF1’s protective effect, so that they can induce damage in the kidney.

 

The EMT angle raises a very interesting point. This paper discusses how various insults to a mouse’s kidneys can cause epithelial cells to transition into activated fibroblasts and cause fibrosis. This is obviously a response to damage and an inadequate cell supply because of short telomeres, with the body doing the best it can to patch up the damage with collagen. But the EMT is also well known in cancer. For example, see the overview, here.

 

Could short telomeres, combined with some sort of insult, cause the increased migration and invasion of cancer cells we see in metastatic dissemination? Something for a future Blasco paper to look into, I’m sure.

Finally, in the paper they take kidney epithelial cells from wild type and short telomere mice. After culture, the cells have partially made the transition to more mesenchymal like fibroblasts, almost 100% in the case of cells from short telomere mice.  Blasco's team then introduce telomerase via a virus vector, and show reversal of this effect, i.e. MET, mesenchymal to epithelial transition. So by lengthening telomeres they restored the cells to their proper phenotype.

Make of that what you will!

[Qowpel]

So I made a statin skin cream. I used Atopalm for the base as it has chloresterol in it, which should counter the negative effects of statins making skin scaly.  I also used Atopalm because it has been shown to reduce systemic inflammation when used on old skin, and is also proven to penetrate the stratum corneum. 

 

See: https://onlinelibrar....1111/jdv.15540

 

 

 

 

It's total guesswork but I've mixed in 100mg of simvastatin and 60mg of telmisartan with 40ml of Atopalm, which I'm applying to the face only in the morning. Simvastatin and telmisartan dissolved very well in the Atopalm. It's hard to say exactly how much I'm using a day but I'd estimate I'll use up the skin cream in 2 months, which means my skin is getting about 1.7mg of statins a day (maybe too much?).

 

I've been using it for a week. No side effects to report. Skin appearance is noticeably improved; the Atopalm seems to remain in the skin all day markedly improving moisture content. At this point it is impossible to attribute any effects to my additional ingredients. 

 

My future plan is to also incorporate azithromycin into the skin cream, as a way of destroying senescent skin cells and making room for any progenitors the statin+sartan combination have created. Unfortunately azithromycin is a heavy molecule, so skin penetration may be limited.

 

 

sounds great for skin. But how do we know it will not affect the adipocytes negatively? I would hate to see it inhibits the proliferation of them or something or ended up ultimately in their apoptosis or shrinkage (and subcutaneous fat is far more important in looking young).... I always feel we should be looking for a topical or oral substance that can aintain our youthful subcutaneous fat levels in the face, but so far I do not think there is one

[QuestforLife]

sounds great for skin. But how do we know it will not affect the adipocytes negatively? I would hate to see it inhibits the proliferation of them or something or ended up ultimately in their apoptosis or shrinkage (and subcutaneous fat is far more important in looking young).... I always feel we should be looking for a topical or oral substance that can aintain our youthful subcutaneous fat levels in the face, but so far I do not think there is one

 

I never got consistent results from my various statin skin creams, unfortunately.

 

If it is subcutaneous fat you are interested in, then you might be interested in post #410 as a possible protocol for increasing subcutaneous fat.

 

I tried something similar many, many years ago and can verify it did increase the percentage of my body weight attributed to fat, as measured by a bio impedance machine.

[QuestforLife]

Summary of GDF11 experience

 

I'm a 42 year old in good health. I decided to try GDF11 because it is known to increase the telomere length in stem cells due to TERC upregulation (see previous posts).

 

December ’20- January ’21: Baseline Biomarkers

See my attached results labelled 'baseline' results whilst I was on a range of supplements, notably AKG. There is no notable improvement on any biomarker during this period, with all biomarkers admittedly already in a good place. Note that I do have supplements that can drop my BP – Pine Bark, Natto Kinase – but they seem to do so at a cost in reducing my HRV. During the baseline period (37 days) I settled on a supplement stack that I then kept (mostly, see later) constant during the GDF11 dosing period. At the end of the baseline period I submitted a methylation age test (result 35.5; previously reported).

 

January – April ’21: GDF11 Biomarker Improvements
See my attached results labelled 'GDF11'. As you can see from the plots, all biomarkers apart from pulse have improved on GDF11. Reaction time improved after the first dose, so the improvement is not properly captured in the chart below, as the GDF11 chart starts on the day of dose 1. Systolic BP was the next biomarker to improve, followed by HRV and Diastolic BP. Unlike the supplements mentioned above, GDF11 can improve BP and HRV together.

 

Synergies
AKG increased the effects of GDF11 and extended out the required time between doses. It may also reduce the total required dose to 'downregulate' (see below). Any side-effects from GDF11 lasted longer when also on AKG. This is not surprising; I’ve posted previously on how GDF11 upregulates one of the demethylases (TET2) and AKG is a cofactor for the demethylases. For this reason, I was on and off AKG during my GDF11 experience.

 

Side-effects
I often felt odd after dosing GDF11, as if my BP had dropped, although measurements did not back up a sudden drop. The most notable side-effect however, was the flaring up of old injuries that I thought had long since healed. My right Achilles tendon was the worst; GDF11 made me limp down the stairs after I got out of bed in the morning. AKG made this discomfort go on for days longer before resolving. I tried fish-oil and this worked to eliminate the discomfort, but  caused a drop in my HRV, so anti-inflammatories may be contraindicated when using GDF11. I’m speculating, but perhaps inflammation is required for rejuvenation?

 

I have put on weight on GDF11. This is both muscle mass and fat, so it is arguable whether this is a side-effect.

 

Other benefits
I’ve noticed better, more steady energy throughout the day since I started GDF11. My skin seems improved. I sleep even better than before and wake up refreshed before an alarm (in fact I don't require an alarm).

 

Future plans and other Test Results
I am approaching 0.5ng total dose but have now reached the point where my biomarkers are continuing to gradually improve, even without further GDF11 dosing. Trying higher doses is not advisable given the side effects reported above. I’ve probably reached the point of ‘down-regulation’ as Steve Perry puts it. I’ll probably only dose GDF11 from now if my biomarkers get worse, or I feel I need it.
I dispatched a methylation age test in March. It shows a small increase in my methylation age from 35.5 to 37.7 since I started GDF11. This may reflect the fact that I’ve not been on AKG much (I’d also dropped berberine since the last result) whilst on GDF11. Or it may be a consequence of increased inflammation caused by GDF11. It could also be within the error range of the test. I’ll restart AKG soon (with berberine).

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Edited by QuestforLife, 06 April 2021 - 09:47 AM.

[yz69]

Don't worry about the trume results, 2year difference is nothing. I did a test, sent out 2 samples on 2 consecutive days, one came back with 45.7 another 44.1, just 1 day difference in samples.

Unless you do lots of trume tests like what you did with BP, reaction times..., the results hardly tell anything.

[dlewis1453]

Summary of GDF11 experience

 

 

 

Excellent and very encouraging results! 

 

I'm hopeful that you will see continued reduction in your epigenetic age, since many people in Steve Perry's cohort see reductions in epigenetic age of around 5 years. This effect may not happen right away. 

 

The inflammation side effect at the sight of old injury is curious. Old injuries often contain large concentrations of senescent cells. GDF11 does have a senolytic effect, so perhaps the inflammation you feel is related to the senescent cells and the process of rejuvenation. 

 

Have you considered continuing with daily AKG dosing, but reducing your AKG dose to a lower level? 

[Castiel]

Was researching vitamin C and came upon some very interesting stuff regards telomeres.

 

First we know that humans have a mutation defect that stops the last step of vitamin c synthesis.   A few other species have a similar mutation, but most take far far more vitamin c intake than humans do.   Some studies tried to say higher doses would be ineffective, but buried within was info that even higher doses did boost blood levels temporarily.

 

Now an experiment was done, iirc, where mice were made to have a similar mutation unable to produce vitamin c.   With low vitamin C supplementation the mutant mice only lived 1/3rd as long as mice without the vitamin c defect mutation.   Now in the experiment some of the mice were also supplemented with high dose vitamin c, instead of low dose vitamin c, achieving similar blood levels as normal mice(without vitamin c defect mutation) despite having the mutation defect.   This tripled their lifespan, compared to low dose vitamin c mutants, and allowed them to live as long as mice that don't have the mutation and normally produce vitamin c.

 

It is unlikely humans would see tripling lifespan, as we probably have evolved multiple adaptations over millions of years to compensate for vitamin c deficiency, which may make up a significant part of the potential lifespan gain from raising blood vitamin c levels.   That said a gain of years or decades is still conceivable.   Even Pauling iirc had two very short lived parents, again iirc, yet lived to over 94 years in mostly excellent health with mental faculties in good condition, bar the cancer he got.

 

Now for where telomeres come in there's an interesting study showing that a form of vitamin C can reduce the rate of telomere shortening by 50-60%.  

 

 

Here, we succeeded in artificial slowdown of age-dependent telomere shortening to 52–62% of the untreated control, in human vascular endothelial cells, by addition of the oxidation-resistant type of ascorbic acid (Asc), Asc-2-O-phosphate (Asc2P), which concurrently achieved both extension of cellular life-span and prevention of cell size enlargement indicative of cellular senescence.

https://www.scienced...024320598003518

 

Now this is one study, which could be suspect, so without further validation or at least personally researching to see if there's more I wouldn't take that particular form vitamin C(I'll be investigating it, but if others have free time feel free to investigate too and post what you find).   The other question is whether other forms of vitamin c would also have similar effects on the rate of telomere shortening.

 

 

In any case if you can lower the rate of telomere shortening by 52-62~% this should greatly improve the tug of war between telomere lengthening compounds and the natural rate of telomere shortening.   Also given that it seems that some versions of vitamin c delay senescence and extend cellular lifespan, there's a chance they may also slowdown rate of epigenetic aging.

 

The tripling of mice lifespan with similar mutation to humans(comparing low dose vit c against high dose vit c, though lower dose than comparative doses in most humans), suggests even regular vitamin c might have similar effects.

Edited by Castiel, 07 April 2021 - 01:57 PM.

[Castiel]

Further research, will read references for the next article but it sounds promising, it covers vitamin c, vitamin e in tocopherol and tocotrienol form, as well fish oil, carotenoids, and vitamin d and their positive effects on telomeres.

 

 

Vitamins C and E Preserve Telomere Length

Studies of vitamin C demonstrate that telomere shortening can be reduced by up to 62% on untreated controls in cultures of human blood vessel cells.20 The result was a significant extension of cellular lifespan, and reduction in physical changes associated with cell aging. This in turn was associated with sharp reductions in cellular free radicals.20

Near-identical results have now been shown in cultures of human heart-muscle cells, demonstrating that vitamin C can work to slow cardiovascular aging by preserving telomere length.21

A dramatic demonstration of the value of vitamin C's role in aging-deceleration was provided by a 2016 study of cellular model of Werner Syndrome, a premature aging disorder.22 After testing numerous compounds for their ability to slow or reverse the rapid aging, scientists identified vitamin C as the most efficient "rescue" for many premature aging characteristics of the cells.22 Treated cells showed longer telomeres, reduced secretion of inflammatory cytokines, and improved integrity of their cellular nuclei, all features of much younger cells. Indeed, in a mouse model of Werner Syndrome, vitamin C rescued aging cells from premature death by altering expression of genes involved in the maintenance of DNA integrity.22

Vitamin E comes in a total of 8 different forms, four each in the tocopherol and tocotrienol categories. Alpha-tocopherol, one of the most-studied forms of vitamin E, dramatically slows age-related telomere shortening, even in the presence of powerful oxidant molecules such as hydrogen peroxide.13,14 This has been proven to result from a tocopherol-induced increase in telomerase that persists even into middle-aged cells.14 Similar results have been shown in cells treated with gamma-tocotrienol, which not only prevented telomere shortening but also enhanced the viability of older cells in culture.23

In a dramatic finding, incubating aging human cells with a tocotrienol-rich formulation reversed the aging-induced structural changes to cells to the point that they resembled younger cells, with less DNA damage and more cells ready for fruitful replication.24 Here again, the effects were attributable to increased telomerase activity.24

https://www.lifeexte...research-update

 

[JamesPaul]

A search of PubMed using the text phrase "Asc2P telomere" turns up the paper below.  It says that Asc2G (Asc-2-O-alpha-glucoside) is more effective than Asc2P (Asc-2-O-phosphate) in slowing shortening of telomeres.  And most importantly, regular plain old Asc (ascorbate) does not slow shortening of telomeres at all.  Interestingly, a dilute solution of hydrogen peroxide worked better than any form of ascorbate at slowing telomeric shortening, presumably because of a hormetic effect.

 

“Slow-down of age-dependent telomere shortening is executed in human skin keratinocytes by hormesis-like-effects of trace hydrogen peroxide or by anti-oxidative effects of pro-vitamin C in common concurrently with reduction of intracellular oxidative stress,” Seiichi Yokoo et al, J Cell Biochem. 2004 Oct 15;93(3):588-97.

 

Some text from the abstract:  "The cellular life-span of cultivated human skin epidermis keratinocytes NHEK-F was shown to be extended up to 150% of population doubling levels (PDLs) by repetitive addition with two autooxidation-resistant derivatives of ascorbic acid (Asc), Asc-2-O-phosphate (Asc2P), and Asc-2-O-alpha-glucoside (Asc2G), respectively, but to be not extended with Asc itself...The PDL-dependent [population doubling level-dependent] shortening of telomeric DNA of 11.5 kb finally down to 9.12-8.10 kb upon Hayflick's limit was observed in common for each additive-given cells, but was decelerated in the following order: 20 microM H(2)O(2) > Asc2P = Asc2G > 60 microM H(2)O(2) > Asc = no additive, being in accord with the order of cell longevity. Intracellular reactive oxygen species (ROS) was diminished by Asc2P, Asc2G or 20 microM H(2)O(2), but not significantly by Asc or 60 microM H(2)O(2)...Thus longevity of the keratinocytes was suggested to be achieved by slowdown of age-dependent shortening of telomeric DNA rather than by telomerase; telomeres may suffer from less DNA lesions due to the continuous and thorough repression of intracellular ROS, which was realized either by pro-vitamin C such as Asc2P or Asc2G that exerted an antioxidant ability more persistent than Asc itself or by 20 microM H(2)O(2) which diminished intracellular ROS assumedly through a hormesis-like effect."

 

Asc2P is commercially available, and I plan to switch to it.  Thanks, Castiel, for pointing us to Asc2P.

 

 

[QuestforLife]

Asc2P is commercially available, and I plan to switch to it. Thanks, Castiel, for pointing us to Asc2P.[/size][/color]

It does look promising, especially as Asc2P is cell permeable. The 130uM used does look like a silly concentration - I've seen similar in Vit E studies showing promising anti-senescent effects - but nevertheless I may switch from the ester-Vit C I currently use.

Note Vit C also activates the TET enzymes and therefore helps with demethylation.

See: Reprogramming the Epigenome With Vitamin C

https://doi.org/10.3...cell.2019.00128

Vitamin C plays a pivotal role in remodeling the epigenome by enhancing the activity of Jumonji-C domain-containing histone demethylases (JHDMs) and the ten-eleven translocation (TET) proteins.