Niacinamide Or Just Plain Niacin?

[Travis]

This had been an unusually thorough study: (1) They had determined the passive membrane permeability each drug, and in two ways; (2) they determined IC₅₀ values for three other methylation enzymes, gauging potential interference; and (3) they had determined IC₅₀ values for two other niacin-metabolizing enzymes, thereby substantiating the accuracy of apparent in vivo NNMT inhibition values.

Neelakantan, Harshini. "Selective and membrane-permeable small molecule inhibitors of nicotinamide N-methyltransferase reverse high fat diet-induced obesity in mice." Biochemical pharmacology (2018)​

 

[Terma]

VVhv? I can imagine that choline indeed might give you more options on what to do with the excedent since the conversion to betaine is irreversible.


The estimation ended up being more or less than you needed?

--
- Management of nicotinamide N-methyltransferase overexpression: inhibit the enzyme or reduce nicotinamide intake?
- Nicotinamide N-methyltransferase promotes epithelial-mesenchymal transition in gastric cancer cells by activating transforming growth factor-β1 expression

Very generally because of the PEMT issue, and dietary choline is less organ-specific. Better building block, yeah. I was taking ~1.5g TMG for ~200-300mg Niacinamide to feel balanced. The calculations I meant the ones I came up with, which are in *.txt file somewhere lost for all time to the knowledge of man (so a lot more TMG than I expected, I assumed due to some gut or distribution issue, or a second pathway they both work on, neurotransmitters, idk).

This had been an unusually thorough study: (1) They had determined the passive membrane permeability each drug, and in two ways; (2) they determined IC₅₀ values for three other methylation enzymes, gauging potential interference; and (3) they had determined IC₅₀ values for two other niacin-metabolizing enzymes, thereby substantiating the accuracy of apparent in vivo NNMT inhibition values.

Neelakantan, Harshini. "Selective and membrane-permeable small molecule inhibitors of nicotinamide N-methyltransferase reverse high fat diet-induced obesity in mice." Biochemical pharmacology (2018)​

Yeah that's the one I linked, only with a nicer PDF than one I got off sci-hub (manuscript), thanks somewhat.

[Edited: Nevermind what was here, I just realized the non quinoline stuff they listed were just controls for membrane permeability]

 

[Terma]

The 1-Methylquinolinium derivatives must be through product inhibition. (trying not to look like an idiot while on 4 hours sleep here)

 

[Travis]

[Edited: Nevermind what was here, I just realized the non quinoline stuff they listed were just controls for membrane permeability]

I thought that was a good point because either a competitor or an inhibitor would lower methylniacin just the same, and inhibitor metabolites had not been determined. However, I think this graph below demonstrates their flagship methylquinoline had inhibited more than it had competed (for methyl groups):

The Y₋axis of Fig. (f) has relative values, yet I am under the impression that N₋methylnicotinic acid (1₋MNA) normally exists in the cytosol at ~1 millimolar concentrations.⁽¹⁾⁽²⁾ Now assuming Fig. (f) is normalized to 1 mM methylniacin, a 10 μM concentration of the methylquinolium inhibitor had abrogated the methylation of ~500 μM nicotinic acid. Even should it be methylated in the process it still inhibits more than it competes.

Also: the N₋methylgroup of methylquinolium is on the ring nitrogen, implying that this might occupy the 'methylation' site of the enzyme's catalytic domain. It could then be assumed unlikely that the primary amino group of methylquinolium would become methylated by said enzyme should it be capable of methylating non₋aryl amines at all.

 

[Terma]

Also: the N₋methylgroup of methylquinolium is on the ring nitrogen, implying that this might occupy the 'methylation' site of the enzyme's catalytic domain. It could then be assumed unlikely that the primary amino group of methylquinolium would become methylated by said enzyme should it be capable of methylating non₋aryl amines at all.

I don't quite follow the graph thing today, but I think that's the part only you could have told me. Yeah I figured there was a small chance the methyl group didn't necessarily mean it wasn't a substrate, but that is must be small. When I don't know, I just go by "common assumption logical probabilities", lol.

I only assumed they were looking for and found a "product inhibitor" because they used that phrase specifically for MNA and they had an interest in that strategy. Even though they or the other group messed up with MNA experiments before (but the same error probably doesn't apply to these other products, so, oh well - I kinda jumped the gun assuming there could be a flaw there when it doesn't really apply).

Apart from that, I'd be interested if you think it's possible for Nicotine (or Caffeine) to be a potent enough inhibitor of NNMT in vivo. It's brought up in the Parkinson's studies: the quote is in this post (Nicotinamide: A double edged sword - ScienceDirect). I doubt anyone else is interested in promoting Nicotine, so... I expect a dead end or undocumented rat deaths otherwise. I couldn't find much concrete info on it, and it's damn hard to search "nicotine nnmt" because the search engines try to be too smart and even NAD spelled out ruins it.

Nicotinamide N-methyltransferase promotes epithelial-mesenchymal transition in gastric cancer cells by activating transforming growth factor-β1 expression

This thing I hadn't seen before; that's quite worrying, TGF-B is quite the boogeyman in causing things like fibrosis.

Honestly I don't quite fully understand the evolutionary logical significance of NNMT yet, but it's been big downstream on us.

 

[Amazoniac]

Honestly I don't quite fully understand the evolutionary logical significance of NNMT yet, but it's been big downstream on us.

I guess that the meaning of this is that it's a regulator: to control oxidation and restrain it to no go beyond what the crayature can afford. Nicotid and caffeid are two substances that increase energy expenditure, this demands oxidation. The clearance of niacin should be reduced when the conditions are right.

Of course you can inhibit this regulator directly with something that has no other function, but uncontrolled oxidation is wasteful and stressful. In spite of niacin's importance, it can only be useful as far as other nutrients allow it to, so I can't imagine it being sustainable over time. An exception to justify addressing it this way is if it's misbehaving for whatever reason, but I don't know how common this is (cancer might be one situation).

 

[Terma]

I guess that the meaning of this is that it's a regulator: to control oxidation and restrain it to no go beyond what the crayature can afford. Nicotid and caffeid are two substances that increase energy expenditure, this demands oxidation. The clearance of niacin should be reduced when the conditions are right.

Of course you can inhibit this regulator directly with something that has no other function, but uncontrolled oxidation is wasteful and stressful. In spite of niacin's importance, it can only be useful as far as other nutrients allow it to, so I can't imagine it being sustainable over time. An exception to justify addressing it this way is if it's misbehaving for whatever reason, but I don't know how common this is (cancer might be one situation).

Yeah, as a general idea it's probably something like that. But loosely expressed in one of the articles is also the idea is there could have been an "overshoot" for times of particular scarcity or particular meat consumption - I'm not sure which - which could have predisposed us to overexpressing the gene.

There's an additional problem where niacinamide can temporally inhibit SIRT1 and do the exact opposite of over-oxidation. One of the other articles mentions that; I find it hard to buy into but there's a circadian aspect to NA and NAD which complicates this entire thing. I find it slightly hard to believe due to dosages required, but can't quite rule it out myself.

 

[Amazoniac]

They discussed the possibility of misbehavior here. But the idea that it's overexpressed in some of those cases to prevent further complications is still valid.

 

[bdawg]

Niacinamide seems outright dangerous.

Especially the insulin sensitivity effects

 

[Curiousman]

Have someone here used niacinamide while fasting ?

 

[Travis]

Yeah I figured there was a small chance the methyl group didn't necessarily mean it wasn't a substrate, but that is must be small.

I think there could still be a small chance: consider the a possibility of it first (1a) becoming demethylated by a nonenzymatic event—or (1b) a different enzyme—only to (2) enter the target enzyme in a demethylated state where it (3) becomes bound upon remethylation. <insert:mushroomcloud.jpg> If this should happen and be remethylated in the process, I think it could technically be considered a substrate—yet an unphysiological one-time substrate. <insert:WWII.kamazee.jpg>

Apart from that, I'd be interested if you think it's possible for Nicotine (or Caffeine) to be a potent enough inhibitor of NNMT in vivo. It's brought up in the Parkinson's studies: the quote is in this post (Nicotinamide: A double edged sword - ScienceDirect).

This is interesting, and I would place a bet on nicotine being a good substrate. I had also become somewhat nonplussed by the unfortunate circumstance they'd both been named after the same Frenchman, making searches for 'N¹-methyl-nicotine' confounded by 'N¹-methyl-nicotinamide.' Yet the N¹-methylated form does not appear to be a common nicotine metabolite, an observation that may seem to imply low a ligand probability yet doesn't necessarily preclude the possibility.

Honestly I don't quite fully understand the evolutionary logical significance of NNMT yet, but it's been big downstream on us.

The first thing I'd do in this instance is to find out how it's regulated. I was thinking that due the number of CpG repeats in its sequence it could be a housekeeping gene, yet its GGTCA sequence also implies ROR control. The suspicion of ROR involvement has been substantiated to a degree by NNMT haven been chosen for inclusion on the list describing gene changes in ROR⁻ rodents—as determined by RNA microarray and confirmed via PCR. This could be some sort of ballast for both excess niacin and methyl groups, operating constitutionally yet upregulated during the night to attenuate the metabolic rate and/or shift the methyl balance.

 

[bdawg]

@Travis any ideas on how to downregulate NNMT

I'm pretty sure i made myself insulin resistant to some extent megadosing niacinamide.

I'm guessing the mechanism is NNMT upregulation in the liver and adipose

 

[Amazoniac]

- Fatty Livers Produced in Albino Rats by Excess Niacin in High Fat Diets: I. Alterations in Enzyme and Coenzyme Systems Induced by Supplementing 40% Fat Diets with 0.1% of Niacin
- Fatty Livers Produced in Albino Rats by Excess Niacin in High Fat Diets: II. Effect of Choline Supplements

"The appearance of fatty livers in animals fed diets high in fat and in niacin could reflect a choline deficiency precipitated by the presence of excess niacin in the high fat diet. This theory is supported by the evidence of Handler and Dann (2), who reported fatty livers produced by the introduction of 2% [a lot] of niacin in a 10% fat diet could be reversed by the addition of choline, betaine, or methionine to the same diet. In addition, Griffith and Mulford (3) reported that the addition of 0.52% of niacin to diets containing only partially protective levels of choline, produced a higher percentage of renal lesions in young rats than the same diets without the niacin supplements. They concluded that niacin exerted a moderate "choline-opposing" action."

"Both groups of workers (2, 3) proposed that choline is used to detoxify niacin. Nicotinamide, the active form of the vitamin, is detoxified in the liver by the transfer of a methyl group from methionine (4), which originates from choline (5), to produce N'-methylnicotinamide (MNA) and related methylated compounds. Therefore an excess of niacin, serving as a drain on the choline pool, could decrease the choline available for phospholipid formation and thus allow fat to accumulate in the liver as a result of reduced fat transport."

"The reversal of the fatty liver syndrome [in this experiment] by incorporating sufficient quantities of choline in the high niacin diets thus provides evidence that the fatty livers in rats fed excess niacin result from an induced choline deficiency. These results are in agreement with those of Handler and Dann (2)."

"The theory of an induced choline deficiency in animals fed excess niacin is supported by MNA excretion data. Animals fed diets high in niacin (0.10%) and in choline (1.00%) excreted significantly more MNA than those fed diets high in niacin and low (0.25%) in choline. Apparently more methyl groups than are supplied by the low choline diet are needed for the methylation of nicotinamide in animals fed excess niacin."

"Data from serum alkaline phosphatase determinations add further support to this theory. Elevated serum alkaline phosphatase activity in the rat is characteristic of choline deficiency (13). The relatively greater activity of this enzyme in serum from animals fed low levels of choline in this experiment suggest that a mild choline deficiency existed in animals from both the group fed adequate niacin and the group fed excess niacin. In the groups fed high levels of choline there was a significant increase in alkaline phosphatase activity when animals were fed excess niacin."

"Animals fed 0.20 or 0.10% niacin showed similar responses. Those animals fed 0.20% of niacin did not differ from those fed 0.10% of niacin with respect to MNA excretion, alkaline phosphatase activity, or percentage of total fat, neutral fat, and phospholipid in the liver. At least 2 explanations can be postulated for these similarities: 1) that the extra niacin was not absorbed, or 2) that the extra niacin was excreted as niacin or some other non-methylated product. There is some evidence to support the latter. Lin and Johnson (18) investigated the excretion of radioactive metabolites in the urine after injections of labeled niacin in the rat. With normal doses of niacin the rats excreted MNA as the chief product, but with high doses of niacin the chief excretory products were nicotinuric acid and nicotinic acid. The excretion of niacin as either of these non-methylated compounds would not affect the supply of methyl groups."

"It is suggested, therefore, that the inclusion of 0.10% of niacin in diets containing non-protective levels of choline induces a slight choline deficiency in young rats. The deficiency is not intensified in animals fed 0.20% of niacin probably because most of the larger supplement is excreted via metabolic routes which do not involve the metabolism of choline."​

 

[Terma]

The first thing I'd do in this instance is to find out how it's regulated. I was thinking that due the number of CpG repeats in its sequence it could be a housekeeping gene, yet its GGTCA sequence also implies ROR control. The suspicion of ROR involvement has been substantiated to a degree by NNMT haven been chosen for inclusion on the list describing gene changes in ROR⁻ rodents—as determined by RNA microarray and confirmed via PCR. This could be some sort of ballast for both excess niacin and methyl groups, operating constitutionally yet upregulated during the night to attenuate the metabolic rate and/or shift the methyl balance.

Ah, really good observation - somehow the circadian regulation didn't cross my mind - meanwhile I'd read tons of stuff on the NAD/Sirt1 regulation in circadiandinadism. D'oh, should've been intuitive.

Based on another study posted earlier (NNMT increased after exercised exhaustion during fasting, seemingly to drive fatty acids from fat/liver toward muscle, or so they think: "On the basis of these findings and the existing literature, we propose that MNA is a myokine
that signals directly to WAT and the liver to mobilize energetic substrates when the availability of energy is low in
muscle."), I'm tempted to think it could increase in the earlier period of the night similar to growth hormone and ablate in the morning (when NAD and Sirt1 are used for the morning boost).

But that's only barely a guess, will have to read more on this later (the damn rodents distort the circadian stuff so much I and clearly some other people have gotten some things completely wrong before, so I'll abstain from pissing not knowing direction of the wind).

Generally since cellular circadian disruptions are symptomatic of so many disorders, it gives another lead.

 

[yomama]

About B3 and NAD, years ago I saved the following quote from a longecity user:

"Essentially it works so that nicotinamide is the salvageable breakdown product that can be recycled back to NAD+. But that pathway gets saturated really easily. Excess nicotinamide floating around will be sensed by the body as there being too much NAD+ around. Which is not at all the case, if you just artificially boosted its breakdown product nicotinamide. This puts the brakes on NAD+ synthesis and all goes down the hill. This is also why nicotinamide is really really toxic to the liver, which is particularly dependent on NAD+. And similarly this is exactly why nicotinamide puts the brakes on SIRT1 expression, which depends on NAD+. So, if you want to mess up your metabolism, increase your risk for diabetes2/syndrome X and age FASTER..then by all means whine about niacin rash and opt for nicotinamide instead"

It is really that way? I mean too much Nicotinamide really causes putting brakes on NAD+ synthesis? I read here and there about NAD and SIRT1 regulation when supplementing with Nicotinamide but I never saw any study depicting it so dramatically as above. Any help welcome.

 

[yomama]

forgot to add his final quote:

However, niacin (nicotinic acid) is converted into nicotinamide in-vivo after ingestion nicotinamide is the breakdown product that the body uses to put the brakes on NAD+ synthesis from niacin

 

[Curiousman]

Mechanism of Inhibition of the Human SIRT3 Enzyme

"Recent evidence suggests that certain symptoms of aging can be reversed in mammals by sirtuin upregulation. In several reports (e.g., [16]), sirtuin upregulation was achieved by increasing NAD+ levels. Reducing NAM inhibition may also be a viable strategy for activating certain mammalian sirtuins."

 

[Curiousman]

About B3 and NAD, years ago I saved the following quote from a longecity user:



It is really that way? I mean too much Nicotinamide really causes putting brakes on NAD+ synthesis? I read here and there about NAD and SIRT1 regulation when supplementing with Nicotinamide but I never saw any study depicting it so dramatically as above. Any help welcome.

This explain beacause the people start fatten with Niacinamide. They started an age process with too much Niacinamide.

 

[yomama]

Mechanism of Inhibition of the Human SIRT3 Enzyme

"Recent evidence suggests that certain symptoms of aging can be reversed in mammals by sirtuin upregulation. In several reports (e.g., [16]), sirtuin upregulation was achieved by increasing NAD+ levels. Reducing NAM inhibition may also be a viable strategy for activating certain mammalian sirtuins."

Thanks for the link, I read in it sentences like "SIRT3 regulation by NAD+ levels in mitochondria was shown to be a primary determinant of cellular resistance to apoptosis" which help understanding the role of Nicotinamide in inhibiting hepatic fibrosis through the induction of apoptosis of out of control stellate cells and consequent reduction of collagen production. That was my interest for Nicotinamide but considering all the above not sure if it is worth using it for that.

 

[Travis]

Ah, really good observation - somehow the circadian regulation didn't cross my mind - meanwhile I'd read tons of stuff on the NAD/Sirt1 regulation in circadiandinadism. D'oh, should've been intuitive.

Based on another study posted earlier (NNMT increased after exercised exhaustion during fasting, seemingly to drive fatty acids from fat/liver toward muscle, or so they think: "On the basis of these findings and the existing literature, we propose that MNA is a myokine
that signals directly to WAT and the liver to mobilize energetic substrates when the availability of energy is low in
muscle."), I'm tempted to think it could increase in the earlier period of the night similar to growth hormone and ablate in the morning (when NAD and Sirt1 are used for the morning boost).

But that's only barely a guess, will have to read more on this later (the damn rodents distort the circadian stuff so much I and clearly some other people have gotten some things completely wrong before, so I'll abstain from pissing not knowing direction of the wind).

Generally since cellular circadian disruptions are symptomatic of so many disorders, it gives another lead.

A dNA search engine confirms RORα response element within niacin N-methyltransferase gene, yet it also has domains many more transcription factors. I had restricted the search to transcription factors that I knew something about, and what I'd excluded are: c-rel, HIF-1, STAT3, Sp1, ERα, etc. Included in the gene sequence are: YY1, RORα, PPARγ, RARα, AP-1, AhR, and the glucocorticoid receptor (GR). [Link 'saved for 7 days.']

Perhaps the methylation has more to do with solubility than anything? The N-methyl group of niacin could increase its penetrance into nervous tissue, and could potentially effect transmembrane flux. Yet, if this were the intention a person could rightly assume that O-methylation would be more effective as this would neutralize niacin's negative charge. However: since niacinamide is already neutral and the amide nitrogen makes O-methylation impossible, the N¹-methylation might appear an intuitive contrivance to increase niacinamide lipid-solubility. Would this N¹-methyl group enhance brain uptake? while transporting one methyl group per niacinamide to the brain for increased cholinergic activity & myelination? However: the fact that niacin has actually been shown to increase cerebrospinal fluid homocysteine concentrations—albeit at massive doses—might imply that N-methylniacinamide does not effectively contribute to cerebral methionine formation. Nonetheless; this enzyme had evolved under natural niacin concentrations, those log orders below those used by: '80s cardiologists, Humphry Osmond, @Amazoniac, and Abram Hoffer. Thus, it may still seem appropriate to imagine niacin N-methylation as a pharmacokinetic ploy that'd evolved with the intent of shifting the body niacin pool towards the muscle, brain, and peripheral nervous tissue. This idea also suggests increased adipocyte compartmentalization as well, which can perhaps be seen either as an intentional way of increasing oxidative metabolism there or merely as an incidental consequence of the more important and intentional CNS uptake.