Oxindole

[Terma]

Sup, I'm so damn short on time and sleep I forget important details that will matter to other people (not me, that's why I forget them) so I won't post for awhile and read instead. It gets tough to catch up on rest and do this at the same time.

@Travis looked at indoles, but I can't find much from him. Has anyone looked at this and if so where are the studies/results posted? Thanks

I think you can figure out what this appears relevant to. [Edit: ME/CFS; just realized that was kind of a d*ck thing to say in the context of that lol]

Oxindole - Wikipedia

Oxindole (2-indolone) is an aromatic heterocyclic organic compound. It has a bicyclic structure, consisting of a six-membered benzene ring fused to a five-membered nitrogen-containing ring. Oxindole is a modified indoline with a substituted carbonyl at the second position of the 5-member indoline ring.

Oxindole is a tryptophan derivative and in human biology is formed by gut bacteria ("normal flora"). It is normally metabolized and detoxified from the body by the liver. In excess, it can cause sedation, muscle weakness, hypotension, and coma. Patients with hepatic encephalopathy have been recorded to have elevated serum oxindole levels.[1]

Sci-Hub | Oxindole. Key Heterocycle Cores for Designing Multitargeting Molecules, 211–246 | 10.1016/B978-0-08-102083-8.00006-6

In this context, the authors have integrated its chemistry and synthetic strategies, naturally occurring oxindole alkaloids, and detailed pharmacological activities including anticancer, anti-HIV, antidiabetic, antibacterial, antioxidant, kinase inhibitory, AChE inhibitory, antileishmanial, β3 adrenergic receptor agonistic, phosphatase inhibitory, analgesic, spermicidal, vasopressin antagonists, progesterone antagonists, neuroprotection, and NMDA blocker activities of oxindole derivatives along with their structure–activity relationship has been discussed.

Synthesis and evaluation of oxindoles as promising inhibitors of the immunosuppressive enzyme indoleamine 2,3-dioxygenase 1

Indoleamine 2,3-dioxygenase 1 (IDO1) is considered as an important therapeutic target for the treatment of cancer, chronic infections and other diseases that are associated with immune suppression. Recent developments in understanding the catalytic mechanism of the IDO1 enzyme revealed that conversion of l-tryptophan (l-Trp) to N-formylkynurenine proceeded through an epoxide intermediate state. Accordingly, we synthesized a series of 3-substituted oxindoles from l-Trp, tryptamine and isatin. Compounds with C3-substituted oxindole moieties showed moderate inhibitory activity against the purified human IDO1 enzyme. Their optimization led to the identification of potent compounds, 6, 22, 23 and 25 (IC50 = 0.19 to 0.62 μM), which are competitive inhibitors of IDO1 with respect to l-Trp. These potent compounds also showed IDO1 inhibition potencies in the low-micromolar range (IC50 = 0.33–0.49 μM) in MDA-MB-231 cells. The cytotoxicity of these potent compounds was trivial in different model cancer (MDA-MB-231, A549 and HeLa) cells and macrophage (J774A.1) cells. Stronger selectivity for the IDO1 enzyme (124 to 210-fold) over the tryptophan 2,3-dioxygenase (TDO) enzyme was also observed for these compounds. These results suggest that the oxindole moiety of the compounds could mimic the epoxide intermediate state of l-Trp. Therefore, the structural simplicity and low-micromolar inhibition potencies of these 3-substituted oxindoles make them quite attractive for further investigation of IDO1 function and immunotherapeutic applications.

Sci-Hub | Pentacyclic Oxindole Alkaloids fromUncaria tomentosaInduce Human Endothelial Cells to Release a Lymphocyte-Proliferation-Regulating Factor. Planta Medica, 64(08), 701–704 | 10.1055/s-2006-957561

In the present study we show that pentacyclic but not tetracyclic oxindole alkaloids from Uncoria tomentosa (Willd.) DC. (Rubiaceae) induced EA.hy926 endothelial cells to release some yet to be determined factor(s) into the supernatant; this factor was shown to significantly enhance proliferation of normal human resting or weakly activated B and T lymphocytes. In contrast, proliferation of normal human lymphoblasts and of both the human lymphoblastoid B cell line Raji and the human lymphoblastoid T cell line Jurkat was inhibited significantly while cell viability was not affected. Tetracyclic oxindole alkaloids dose-dependently reduce the activity of pentacyclic oxindole alkaloids on human endothelial cells.

Protein restriction in hepatic encephalopathy is appropriate for selected patients: a point of view

Compared with meat-based protein, vegetable protein is poor in the sulfated amino acids methionine and cysteine, which are precursors of the mercaptans and indole and/or oxindole compounds which have been implicated in the pathogenesis of hepatic encephalopathy [30]

Sci-Hub | The Chemistry of Oxindole. Chemical Reviews, 37(3), 443–479 | 10.1021/cr60118a003
https://www.researchgate.net/public...Their_Pharmaceutical_Significance-an_Overview
Oxindoles - an overview | ScienceDirect Topics
Sci-Hub | Peripheral and splanchnic indole and oxindole levels in cirrhotic patients: A study on the pathophysiology of hepatic encephalopathy. Digestive and Liver Disease, 41(3), A24–A25 | 10.1016/j.dld.2008.12.052

 

[Terma]

In ME/CFS, if other indoles were competing with tryptophan for IDO, this could potentially explain the observation that - despite the IDO trap hypothesis suggesting that ME/CFS is an intracellular tryptophan overload - some patients reported on forums they felt relief from consuming high amounts of tryptophan from supplements and whey: because in that case the excess Trp helps outcompete the competing indoles for IDO enzymes, to fuel the kynurenine pathway. That said, the IDO hypothesis itself was not yet something proven last I read and this is more like a variation on it.

 

[SB4]

@Terma Certainly is quite interesting. Could explain how some people have gained improvements or remission (FMT) from modulating gut flora. Still relies on the TRP theory being legit though.

 

[Terma]

@SB4 Yeah, but it has some different characteristics than the current IDO theory.

Here is a second layer of metabolic derangement that is known to at least be possible, and that could cause issues in ME/CFS:

If IDO is saturated, then Kynurenine 3-monooxygenase - Wikipedia (KMO) might also get saturated with something as long as there is sufficient NADPH for KMO. But if a large amount of substrate were to pass through KMO, then it might contribute to a drainage of NADPH, or at least an extra competitor for NADPH as a substrate. NADPH deficiency leading to under-working KMO is in fact a factor in Lupus (Comprehensive metabolome analyses reveal N-acetylcysteine-responsive accumulation of kynurenine in systemic lupus erythematosus: implications for a... - PubMed - NCBI), so this is within the realm of possibility.

Some people with ME/CFS reported developing it after taking accutane. It just so happens that retinoic acid (RA) requires NADPH for its degradation by the CYP26 enzyme - also a monooxygenase - so it could conceivably rob NADPH from KMO and lower its activity if RA found itself accumulating in the right cell types.

Also there's no forgetting that NADP is an expensive product of the pentose phosphate pathway and it is thus possibly getting tied up in the kynurenine pathway (also via TDO) instead of some better use.

KMO requires both NAD(PH) and FAD (as a coenzyme).

Everything regarding KMO rides on the assumption that the flux through KMO is high or at least that it significantly impacts NADPH availability for other enzymes and processes. You could have accumulation of Trp and Kyn in different ratios depending on which enzyme (IDO/TDO vs KMO) is rate-limiting.

 

[Terma]

@SB4 Please note I can't post on phoenix rising anymore because they put me on permanent moderation 2 years ago and I still can't message anyone. If you think this is interesting enough and nobody already did it, you could maybe send the link to this thread and the travis thread post to nandixon in a PM. If you want.

 

[SB4]

@Terma its a shame you can't post over on PR. I have seen and experienced excessive moderation over there. What did they ban you for?

Perhaps you will have more luck over there if you started a new account as about 1.5yrs ago there was a big split where half of the users left and formed another site S4ME, however IMO the moderation is even worse there.

As far as I understand it, though I might be wrong. IDO1 is saturated but substrate inhibited, meaning that it doesn't end up making much kynurenine at all, and since IDO2 is supposedly bust, you would have less kynurenine so KMO would be less active.

 

[Terma]

That's the difference between this idea and that guy's (forgot his name): IDO2 is not necessarily required to be bust; it's the competition for the IDO enzymes - or a direct or indirect inhibition by oxindole/indoles - that drowns Trp conversion out primarily, in theory. And possibly another aspect of indoles like oxindole - I couldn't read everything and I won't be able to do much this week or maybe this month, so I'll just be sitting on this, you see.

In this idea, IDO2 dysfunction might maybe do something like introduce a greater range of severity seen in the disease, manifest as more severe sub-cases. In cases where IDO2 isn't bust, then it's plausible its cell types - along with those where TDO dominates [even if it processed only Trp and not other indoles - I'm not sure what it can do] - could suffer from NADPH depletion at KMO. NADPH can clearly be deleted enough to cause excess Kyn, but yeah it depends what the IDO/TDO enzymes look like - and it's cell type dependent. It's relevant for TDO in liver and brain as well, which globally affects Trp availability.

I don't want to post there again, honestly. I don't want to care about those things now. I liked several users there but I have my limits with admin behavior. I just came off angry in a drunk post one time (unrelated to the forum split - I was neutral in that, both directions looked wrong to me) and they decided that deserved a life sentence. I don't have time for that at this point in my life (and iirc new accounts have limited rights too). If someone wants to link this to nandixon or Hip, those guys just kinda knew how to vet these ideas and nandixon was talking to Ron Davis at one point. The other dudes got banned worse. I don't know what these people are doing now, but Hip never goes away. nandixon doesn't appear to be a username on s4me.info.

 

[SB4]

Okay I think I see now. I'm just anxiously waiting for some experimental results that show elevated TRP or other such clue in the relevant cells. Until then, I am quite interested in the idea, but also cautious / lukewarm on it.

Fair enough. Yeah Hip is an absolute machine, been cranking out quality posts for about a decade now.

How are your symptoms? What has helped you so far?

 

[Terma]

Trp is a good candidate in general, purportedly (Travis knew more about this) even without kynurenine or serotonin it can act as a sedative. Kynurenine leads to the autoimmune issues by driving T-cells (see Lupus, again). You could have a range of issues depending on their concentrations and tissue distribution. There are even additional enzymes Travis talked about that high Trp and indoles might cause issues with, but I haven't gotten around to re-reading his posts.

I no longer really have symptoms that suggest ME/CFS specifically, although I got stuck with another battery of problems. I already made a post before I left about random things I was taking at the time, but I can't tell what really helped. Curiously it involved taking a lot of R5P/B2, and that happens to modulate the gut microbiome as well as being a coenzyme for KMO. Also high doses of adamantane were taken around that time and it happens to have a strong effect on the gut (and supposedly 5-HT3). [Also: I took high doses of agmatine sulfate at the same time as high-dose adamantane at one point] But I have no idea if these affect the bacteria that produce oxindole or other indoles.

 

[SB4]

@Terma Are those Travis convos PMs or on the forum somewhere?

Interesting about the B2, I am currently taking it but just regular riboflavin. I had an EGRAC test that showed B2 deficiency. I was taking it in the morning however my eyes started hurting / going a bit blurry so I have moved it to night time as B2 reacts with light.

You might not have seen the threads on PR but Robert Phair (the TRP Trap guy) posts sometimes, apparently they are having difficulties with getting sensitive enough equipment to accurately measure TRP in cells. They also do not know which cells to test.

 

[Terma]

There was a huge thread on B2 on phoenixrising and several people benefit from it - temporarily. At some point I also had eye problems and it didn't appear to be Srojen's, and again I'm not sure what helped that (I suspected amino acids like lysine but who knows). Clearly B2 on its own was never enough, but it's essential.

Thanks for the info (right, Phair).

Travis wrote me some of his ideas in PMs, a few were probably not in his posts but he didn't go into super detail on them. Some of them he brought up on the forum - I'm almost sure I saw him make posts about indoles in general - but I can't go over his post history today.

[Also: Don't forget thyroid is a requirement for FAD synthesis, and folate/methylfolate/b9 - which benefits some people - in high doses may be able to produce NADPH (Quantitative flux analysis reveals folate-dependent NADPH production) - I posted this in someone else's thread; Kimsie brought it up]

 

[Terma]

Also don't forget: NADPH is a cofactor in allopregnanolone synthesis (5-alpha-reductase type 1). Curiously there was a post over at Health Rising blaming high progesterone or something for some subset, I don't remember.

I think NADPH is - among other things - one of the "end of day" signals that helps the circadian rhythm run notably through inhibitory/recovery neurosteroid synthesis, and possibly also through CYP26 degradation of retinoic acid, which in turn - possibly - helps to allow the liver methylation cycle to take over for the night (because RA upregulates GNMT, impeding methylation). [RA helps maintain a kind of "steady-state" during the daytime by controlling GNMT, loosely similar to how it associates with differentiation]

As to what actually helps me now, let me tell you guys something: all these posts are written thanks entirely to (in order of importance), all at once except DHEA+prog is the night before: pure THC oil, tons of pure caprylic acid (C8) oil, food to help the C8 absorb, tons of sugar, DHEA and progesterone, magnesium aspartate, and optional high-dose taurine, histidine + beta-alanine (carnosine), and ribose. The ketones are a huge factor in how my brain works, but they have to absorb and I think THC (5-HT3 antagonist) + food helps with that. I know Hip has problems with brain fog so I figure I'd post these again. I might be forgetting a thing or two.

 

[Terma]

Here is the paper where I first heard about oxindole:
Sci-Hub | Is the interaction between fatty acids and tryptophan responsible for the efficacy of a ketogenic diet in epilepsy? The new hypothesis of action. Neuroscience, 313, 130–148 | 10.1016/j.neuroscience.2015.11.029

It just happens to be one of the most helpful papers I've read about neuron and astrocyte interaction as relating to ketones increasing NAD; I was still digesting some of it (it will help me explain my own neurological disorder). I have Alexandra Elbakyan to thank for that one.

 

[SB4]

@Terma Yeah I think hormones can play a role in modulating the disease. I have read several accounts of hormones improving symptoms but they all seem to be different. There was a thread recently of somebody who did a sex change that cured them and thought it was lower T that did it. There is a thread of increasing T causing significant improvements of symptoms. Then there is me who saw no real difference being high T and low T.

There is also @Antonello who was helped significantly from DHEA. I think these hormones are modulating something, probably in the immune system but also could be metabolic. It just depends on your particular context if it helps or not.

Interestingly I am reading through some big blog posts on NAD, I figure it could help skirt lactic acid problems via several mechanisms. I came across a study however of NADH supplementation in ME/CFS and it showed significant improvement in symptoms (they also used CoQ10) and they actually measured the NAD/NADH ratio and it went down! This is confusing for me as my understanding would be you would want the ratio to go up!

I figure that if you have lactic acid build up, this is because you are running on glycolysis and thus need to free up excess NADH to NAD+ to keep glycolysis running and cells alive. Yet in the study it went down and they improved. Also what is confusing is how did the supplement NADH get absorbed as NADH? If you take NAD+ it gets broken down into nicotinamide riboside and adenosine diphospahte in the intestines as far as I am aware.

Anyway, interesting about the ketones and NAD, also that you have too seen improvements with MCTs. You say lots of sugar helps, is this in congunction with MCTs (taken at the same time)? For me I figure the MCTs are providing me with the acetyl CoA that is lacking upon ingestion of carbs. Might have to try THC at some point. Tried histidine recently and that night when I put a little pressure on my arm it felt like my arm was about to snap off. The bone hurt all through the night so I stopped taking it.

 

[Terma]

Yeah DHEA has a lot of actions, even 5-HT3 antagonism, IGF-1 (I think Hip or someone had a thread on this one, e.g.: Insulin-Like Growth Factor-I Regulation of Immune Function: A Potential Therapeutic Target in Autoimmune Diseases?), glycogen/glucose metabolism since you have studies like this one suggesting lower glucose availability in some cell types, etc. I take progesterone with it but I suspect the people with ME/CFS should not (they need more conversion to allopregnanolone... probably). I've always been roughly normal T.

Yep I recall people were interested in NADH/NADPH for some reason a few years back and some people getting results from NADH supplements. And it's interesting the reduced form of NAD/NADP seemed to be what helped. If you have the link to that study I could (re-)read it another day. But that's certainly in line with the above.

In some cases it could be simply because the limiting factor was the NAD molecule itself, rather than NAD or NADH in particular. This can be easily explained as a defect in the pentose phosphate pathway which produces PRPP (ribose) for NAD synthesis while also generating NADPH (and CO2) from NADP. Some users suspected this a long time ago. So whether you add NAD or NADH in that case you get an improvement.

This is in line with D-Ribose being a popular supplement for ME/CFS. [I can also say this: after I seemed to no longer have ME/CFS-like symptoms, D-Ribose no longer energized me as frenetically as is it did before; now I barely notice it unless with THC and even then it's much weaker than caprylic acid; the only complication is that it's also known to modulate the gut microbiome iirc; and also forming AGEs]

Yes, I take caprylic acid at the same time as something sugary and some food with protein and fat (saturated/monounsaturated), including starch (sushi rice) if it's a bigger meal.

I think histamine is involved in the sense of touch. That sounds unusually extreme, though. (Do you have allergies or mast cell disorder? How much histidine did you take at once?)

 

[Terma]

I think I should emphasize: the odds of an insufficient PPP in people with ME/CFS seem decent to me, or at least past a certain severity. That could conceivably lead to Lupus-like lower KMO, and then every insult to NADPH on top is an extra injury. I would say even if the entire Trp theory were wrong, it still seems likely they have problems with the PPP, or that it's under quite some pressure. [It was already brought up in papers by prominent figures] [And not to forget: the folate contribution to NADPH]

 

[Terma]

Oh I almost forgot: at some point I was taking tons of taurine and also TUDCA, and the other day I landed on this funny quote, not sure what was the quality of this study, and am not sure if anyone picked this up so I don't really have a choice to mention it:
Metabolic profiling of a myalgic encephalomyelitis/chronic fatigue syndrome discovery cohort reveals disturbances in fatty acid and lipid metabolism

The pathway with the highest impact factor is the taurine and hypotaurine metabolism with taurine (28) as the central compound of this pathway (Fig. S4A). A decrease in concentration of this metabolite might reflect a general effect on this pathway and the consequences associated with the general metabolism of the body. Of important note, taurine is also part of the primary bile acid biosynthesis pathway where three of the near-final products (16, 19 and 28) are found to be reduced in patients according to our measurements (Fig. S4B). The main function of bile acids is to physically support the digestion of dietary fats.

(Again: bile modifies the gut microbiome)

 

[Terma]

Oxindole, a sedative tryptophan metabolite, accumulates in blood and brain of rats with acute hepatic failure. - PubMed - NCBI

Rats treated with oxindole (10-100 mg/kg i.p.), a putative tryptophan metabolite, showed decreased spontaneous locomotor activity, loss of the righting reflex, hypotension, and reversible coma. Brain oxindole levels were 0.05 +/- 0.01 nmol/g in controls and increased to 8.1 +/- 1.7 or 103 +/- 15 nmol/g after its administration at doses of 10 or 100 mg/kg i.p., respectively. To study the role that oxindole plays in the neurological symptoms associated with acute liver failure, we measured the changes of its concentration in the brain after massive liver damage, and we investigated the possible metabolic pathways leading to its synthesis. Rats treated with either thioacetamide (0.2 and 0.4 g/kg i.p., twice) or galactosamine (1 and 2 g/kg i.p.) showed acute liver failure and a large increase in blood or brain oxindole concentrations (from 0.05 +/- 0.01 nmol/g in brains of controls to 1.8 +/- 0.3 nmol/g in brains of thioacetamide-treated animals). Administration of tryptophan (300-1,000 mg/kg p.o.) caused a twofold increase, whereas administration of indole (10-100 mg/kg p.o.) caused a 200-fold increase, of oxindole content in liver, blood, and brain, thus suggesting that indole formation from tryptophan is a limiting step in oxindole synthesis. Oral administration of neomycin, a broad-spectrum, locally acting antibiotic agent able to reduce intestinal flora, significantly decreased brain oxindole content. Taken together, our data show that oxindole is a neurodepressant tryptophan metabolite and suggest that it may play a significant role in the neurological symptoms associated with acute liver impairment.

Something less important but still:
Synthesis, Antimicrobial and Antioxidant Activity of Some Oxindoles

Balance of saccharolysis and proteolysis underpins improvements in stool quality induced by adding a fiber bundle containing bound polyphenols to either hydrolyzed meat or grain-rich foods

Fecal 2-oxindole-3-acetate was significantly decreased in both healthy dogs and those with chronic enteritis/gastroenteritis when fiber was added to the HM food, but only in healthy dogs when added to the GR food (p = 0.002), a response that differed by health status (p = 0.045 for difference by health status). Other indole derivatives were not significantly changed by fiber addition to either food.

 

[LeeLemonoil]

Terma, thanks. Very interesting reasonings and Information here.


Indoles: Some common, heavily used aromachemicals used in mainstream perfumery are derived from or similar to indoles and benzofurans. I assume they act as mood-altering drugs via inhalation and are active on some GPCRs or who knows which receptors.
Most aromachemicals are actives in some way or the other, it’s not feasible why so many people like to envelop themselves with synthetic smelling mess otherwise if it wasn’t for a drug like effect

 

[SB4]

@Terma Here is the study I was referring to.

Note that the NAD+ goes down by 100 and NADH goes up by 100. So it seems that it isn't the lack of NAD molecule that is causing problems. I am still confused how NADH reaches the cells without being broken down. I have read elsewhere but no idea if it is correct, that the average NAD+/NADH ratio is 2-4. Note it is 2 (so at the bottom end of normal) usually but post supp it drops to like 0.3.

Since the NADH (if it gets this far) should be entering the cell through the cytosol, and NADH cannot make ATP in the cytosol and cannot directly move into the mitochondria without getting shuttled in by other pathways of which I assume are relatively slow, wouldn't you expect the cells to be producing a ton of lactic acid in order to keep glycolysis and energy production going?

I thought this would make patients much worse but they improved. Perhaps @haidut could help work it out?