#41

Thanks! This will make for interesting reading.

#42

Yes I disregard all in vitro studies unless the concentration used in vivo can reasonably be reached in vivo after consumption by humans, which is almost never the case. You mentioned curcumin and quercetin. They are prime examples. They are poorly absorbed and heavily metabolized. If someone shows me a study where curcumin or quercetin inhibit mTOR at some tiny nanomolar concentration and that such concentrations are seen in the blood after ingestion, then we’re talking. But this is highly unlikely.

Whenever I see something having a particular effect in vitro, I take note of the concentration and then look at what concentrations are seen in the blood of humans after ingestion of that compound and the latter is almost always far too low to expect the effect to be seen in vivo.

The same is true for other pathways besides mTOR. If you look up supplements that may influence some pathway, e.g. IGF-1, AMPK or what not, you will find tons of studies on various supplements being connected to the pathway in some in vitro conditions, but at least 95% of them won’t have any significant effect on that pathway in vivo at reasonably ingested doses. That’s why my deffault assumption is always that in vitro doesn’t translate to in vivo. Exceptions are likely seen when the concentration tested in vitro was exceptionally low, like low nanomolar, or when the compound is highly bioavailable after ingestion.

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#43

Olafurpall:

Your point that the concentrations tested in vitro are almost never reached after consumption by humans seems most relevant and I am gladly open to changing my view.

You write: “That’s why my default assumption is always that in vitro doesn’t translate to in vivo. Exceptions are likely seen when the concentration tested in vitro was exceptionally low, like low nanomolar, or when the compound is highly bioavailable after ingestion”.

Let me take a dive into the example of curcumin. The lowest in vitro concentration I found on curcumin affecting mTOR is 2,5 micromolar, i.e. 2500 nanomolar, much higher than the level you indicate should be a concern.

But what about a curcumin formulation developed for high bioavailability, showing inhibition of mTOR signalling in vivo, with the study highlighting the mTOR inhibition effect? Is there no or little risk of (negative) interaction with e.g. rapamycin? Potential therapeutic effect of curcumin, a natural mTOR inhibitor, in tuberous sclerosis complex - ScienceDirect From the study:

“Recent studies suggest that curcumin inhibit mTOR activity in vitro , which prompts us to investigate curcumin function as a new class of mTOR inhibitor suitable for tuberous sclerosis complex (TSC) treatment”.

“Solid lipid curcumin particle (SLCP), a novel curcumin formulation, was used to treat TSC related manifestations in Tsc2 knockout mice”.

“First, we evaluated the effect of curcumin on AMPK and mTOR pathways in vivo . Eight week-old WT male mice were i.p. injected once daily for 7 days with the vehicle or 300 μg of solubilized solid lipid curcumin particle (Longvida®)”.

“Results

Recognition memory deficit began as early as 4 weeks of age in both male and female Tsc2+/− mice. Oral administration with SLCP activates AMPK activity and inhibits mTOR activity in the brain tissue of Tsc2+/− mice, and can rescue the electrophysiological abnormality and object recognition memory loss in the mice”.

Conclusions

Our results suggest that SLCP could be an effective treatment for TSC patients”.

Or take the formulation I have, NovaSol A1 Vitality, with 185 times the bioavailability of unformulated curcumin based on blood measurements according to Consumer Lab and based on an independent analysis of bioavailability studies (which were mostly done by the manufacturers). https://pubmed.ncbi.nlm.nih.gov/30006023/).

The reasons for NovaSol´s superiority are given in Increasing Post‐Digestive Solubility of Curcumin Is the Most Successful Strategy to Improve its Oral Bioavailability: A Randomized Cross‐Over Trial in Healthy Adults and In Vitro Bioaccessibility Experiments (wiley.com) But drawing conclusions from the effects of molecular concentrations written here on mTOR interaction with e.g. rapamycin Is beyond my capacity.

#44

I study the effects of HDAC inhibitors (such as curcumin) rather than mTOR inhibitors (other than Rapamyin).

Most of the HDAC inhibitors popularly used for longevity (of which there are quite a few) have IC50 levels in the tens of micro molar.

The inhibitors used often for their anti cancer effects run at the nano molar level, but in fact the HDAC inhibitor most known for its epigenetic effects is 10-hydroxy-2-decenoic acid or 10-HDA found in Royal Jelly and it acts to create the Queen Bee phenotype (not in isolation, but it is a key part of the process).

What I have found with the micromolar ones that if you take a combination in sufficiently high quantity you can get a dose dependent result.

If it were to be that the only thing that matters is mTOR then the same approach would be possible.

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#45

This is an interesting paper discussing studies of combinations of interventions on worms, flies and yeasts resulting in compounded increases (and decreases) in lifespan. I assume all the positive studies are listed but most of the negative studies never got published. The big effects seem to be combinations using gene alterations. Other combinations using cancer drugs and antibiotics are interesting.

The more I think about taking additional serious chemicals the more I am convinced that I need more time in health to allow me to wait to benefit from anti-aging interventions that get past studies on larger mammals (vs worms, flies, mice). The key is to do the basics right and not injure myself in the meantime.

The basics:
Sleep (& circadian rhythm)
Diet (calories, gut health, protein, nutrients, timing, fasting)
Exercise (strength, cardio, mobility, balance)
Stress (social, nature, fun, dogs, family)
Other (hydration, sunshine, purpose, accidents)

What am I missing?

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#46

As you probably know at the core of this I think it is an issue about reducing senescence (hence having enough acetyl-coa in the nucleus, but you can exogenously increase acetyl-CoA levels) and having efficient mitochondria (which has an impact on acetyl-CoA levels, but also affects the ATP response to the ATP/ADP gradient).

At a cellular level micronutrients are also important for cellular function.

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#47

I’m beginning to come around to thinking mitochondria are the key. Sufficient energy to run (and maintain) the body properly without excessive energy production related wastes products. Perhaps you’ve said this before. I’ve been hearing it in multiple places. I continue to think re-establishing the normal cycle of growth / replacement of proteins vs scavenging of old proteins is important. I don’t understand how these are connected but perhaps you do. Rapamycin plus exercise plus not doing stupid shit. Plus what?

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#48

Caloric restriction?

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#49

A key part of cellular activity is producing proteins. This takes a lot of energy. It has two key stages, the transcription of DNA producing mRNA and then the Ribosome takes this and produces proteins.

At the transcription stage it can produce splicing variants if there is not enough acetyl-CoA or some other impact on RNA Pol II.

At the translation stage if a protein production goes wrong it goes to recycling (RQC). I think this relates at times to a shortage of ATP causing a delay in protein produciton.

New mitochondria are efficient and respond to the ATP/ADP gradient by producing more ATP, but as they get harmed they get less efficient and don’t respond.

Hence efficient mitochondria are needed to make sure that proteins are produced properly.

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#50

CR is a route to autophagy.

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#51

Thanks. Good explanation.

#52

I have read that most cancers start in the mitochondria. So, they are critical to keep in good health.

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#53

Dark Chocolate!!!

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#54

I love dark chocolate. But I ruined it by going for ever higher percentages of cacao until I was using 100% cacao powder.

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#55

what % is acceptable to you? 70%? Anything higher than that, started to taste like medicine.

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#56

After eating 100% for a while, you grow to like it. It’s an acquired taste like beer or coffee.

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#57

The chances of interaction with rapamycin are certainly much higher with curcumin formulations designed for higher bioavailability, but I’m still going to strongly doubt curcumin will reach high enough concentrations to interfere unless and until I see a study showing that orally ingested curcumin reaches concentrations in the blood that are of importance here. I say this in particular because I know curcumin is heavily metabolized in the digestive tract and the liver, so even with a formula that has improved absorption the first pass metabolism in the liver would metabolize a lot of it before it reaches the systemic circulation.

The mice were given the curcumin with intraperitoneal injection. That bypasses the liver and intestines and makes the curcumin far more bioavailable. Curcumin is heavily metabolized in the intestines and by the liver after ingesting it orally so whatever you get from an intraperitoneal injection is likely to be a lot higher concentration than what you would get from ingesting it.

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#58

Olafurpall:
“…but I’m still going to strongly doubt curcumin will reach high enough concentrations to interfere unless and until I see a study showing that orally ingested curcumin reaches concentrations in the blood that are of importance here…”.

Should this mean that oral curcumin will be unlikely to have any significant effect on humans on the whole? Is what you write in contradiction to the clinical trials showing some efficacy of oral curcumin on various diseases in humans, with the concentrations in blood (presumably) being high enough for beneficial effect? Therapeutic Roles of Curcumin: Lessons Learned from Clinical Trials - PMC (nih.gov)

Thanks for having patience with my barrage of text!

.

#59

The argument about Curcumin is that it activates CYP 3A4 in the gut which prevents Rapamycin from being absorbed. If, however, you take the rapamycin first (by a few hours) then this should not be an issue.

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#60

No it’s actually not in contradiction with the clinical trials on curcumin and doesn’t necessarily mean that curcumin won’t have significant effects on humans. The fact that ingested curcumin is heavily metabolized into other compounds in the digestive tract and liver just means that whatever significant effect it is having on humans after ingestion is likely to be caused by these metabolites rather than by curcumin directly.

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