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New evidence for cancerogenic metabolites from JWH-018

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MurphyClox

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It was speculated numerous times if JWH-018 and its close congeners (in particular 015 and 073) could act as cancerogenics. See e.g. this thread (JWH-018-related; very lenghty) and this thread (JWH-073-related).

To repeat the mentioned arguments in short:
For JWH-015 it was shown (using fractions of liver microsomes, to emulate the metabolic environment of the rat liver) that certain pathways of the compounds metabolism included epoxide-intermediates, which are quite infamous for causing cancer, similar to benzen's metabolism. The respective reference is Analytical and Bioanalytical Chemistry 2006, 386(5), p.1345.
Because in particular JWH-018 is structurally very close related to JWH-015, it was assumed by some folks (incl. me) that JWH-018, a very popular 'legal' cannabinoid, is potentially harmful.
Of course, one has to add to the discussion the numerous by-products of the synthesis, which were not removed lege artis in the first batches (...which were orange coloured), but this should not be part of this thread and is another topic.

This discussion was, of course, quite speculative due to the lack of appropriate metabolism studies with JWH-018 and lots of people disagreed with the cancerogenity-proposal.


Now I have found novel evidence that the doubts over JHW-018's benignity were justified. (Thx to Vecktor, who posted the resp. link elsewhere, where I now found the info). I quote:

Studies on the metabolism of JWH-018 and of a homologue of CP 47,497, pharmacologically active ingredients
of different misused incense (“Spice”) using GC-MS and LC-MSn techniques


T. Kraemer, K.Y. Rust, M.R. Meyer, D.K. Wissenbach, D. Bregel,
M. Hopf, H.H. Maurer, J. Wilske

(Institute of Legal Medicine, Saarland University, 66421 Homburg,
Germany; Experimental and Clinical Toxicology, University of Saarland,
66421 Homburg, Germany)

Introduction: In the last few months, a new drug has conquered the cannabis market: different types of incenses (trade names “Spice”, “Smoke”, “Sence” and others) have widely been misused by smoking these blends of herbs. Recently, artificial endocannabinoid receptor agonists (JWH-018 and a homologue of CP 47, 497) have been found to be the pharmacologically active principles in these blends. Unfortunately, little is known about these substances.

Aim: The aim of this study was to elucidate the metabolism of JWH-018 and of a homologue of CP 47,497 (CP47).

Methods: Ethanolic extracts were prepared from incenses containing JWH-018 and CP47, respectively. After removal of the ethanol the residues were given to Wistar rats by gastric intubation and urine was collected over 24 hours. For identification, the metabolites were isolated after enzymatic or acidic cleavage of conjugates by liquid-liquid extraction (LLE) or solidphase extraction (C18 ) followed by acetylation and GC-MS analysis. For LC-MS the underivatized extracts were used. Metabolites were identified by interpretation of the EI mass spectra (GC-MS) and enhanced product ion (EPI) scan mass spectra (LC-MS). MS3 experiments allowed differentiation of isomeric metabolites.

Results: The parent compounds JWH-018 and CP47 could be found in the urine extracts. For JWH-018, the N-dealkyl metabolite could be detected as well as the hydroxylated metabolite. The highest signals could be observed for the hydroxylated N-dealkyl metabolites. Hydroxylation took place in the side chain and in both aromatic systems, the naphthalene and the indol part, which could be shown by mass shift of the corresponding fragments and by MS3 experiments. For CP47, several hydroxylated metabolites could be identified. Aliphatic hydroxyl groups could be differentiated from aromatic hydroxyl groups by different fragmentation patterns (loss of water/acetic acid for aliphatic hydroxyl groups).

Conclusion: JWH-018 and CP 47 are extensively metabolized in rats. According to our experience similar metabolic patterns can be expected in humans. Therefore, screening procedures for these drugs in urine should include not only the parent compound but also the corresponding metabolites.
(highlights added by me)

So what's the message?
The usual metabolic pathway to aromatic hydroxy-functions goes via epoxides!!!
Therefore I conclude that the fear for the potential cancerogenity of the JWH-compounds, in particular those with a very low sustitution pattern, were justified. I don't say this is THE evidence, but the new info definitively speaks against the presumable benignity of these compounds.


- Murphy
 
Last edited:
I saw that, it is in the same location as the mephedrone metabolism study

ring hydroxylation of naphthylene rings was almost inevitable.
 
Hydroxylation of naphthalenes may go through arene oxides, though that is not exactly clear. The observation of NIH-shift rearrangement products from oxygenation of aromatics goes back to the 60's and was proposed at the time as evidence for arene oxides (epoxides). However, it is really evidence for carbocations. Only in the case of higher polycyclic aromatics like phenanthrene are epoxides actually stable enough to be isolated. It is these quasi-stable epoxides that are the problem, since they last long enough to make it to the nucleus and react with the DNA. I don't think that, at the levels that these JWH drugs are in the body, it is that much of a danger. A common over the counter analgesic, naprosyn, contains a naphthalene ring, and it is not thought to be a carcinogen. Naprosyn is taken at doese as high as 500 mg twice a day, and can be taken for weeks at a time. Benzene is a carcinogen, but only at very high levels of exposure for long periods of time.
 
Metabolism via ring hydroxylation of the naphthyl moiety is not necessarily bad or carcinogenic, for instance see the metabolism of duloxetine. The problem is moreso with the non-etherized compounds for some reason, for instance both duloxetine and propranolol have the naphthol moieties as an ether and are not problematic (that much), but pronethalol is very carcinogenic. For some reason straight carbon chains or no carbon chains are the big problem from naphthalene, which I can't explain at the moment.

A common over the counter analgesic, naprosyn, contains a naphthalene ring, and it is not thought to be a carcinogen. Naprosyn is taken at doese as high as 500 mg twice a day, and can be taken for weeks at a time. Benzene is a carcinogen, but only at very high levels of exposure for long periods of time.
Bad example because the major metabolic route of naproxen is demethylation of the ether which paves the way to gluconoridation and excretion, thus circumventing the oxidization of the ring.
 
Just to put this into perspective, and I hope I'm not trying to simplify this too much:

How bad is JWH-018 compared to other known carcinogens.

Is this closer to the carcinogenicity of tobacco smoke? or are we talking on par with mesothelioma?

less? more? It would help to know what type of risk one is putting themselves in, as opposed to just knowing that there is a risk.
 
in the past someone said they thought JWH-250 would be no less toxic than naphthalene containing AAIs (ie the naphthalene moiety is a red herring) does this still hold true?
 
@Tryp2Fun:
As Nuke already said: Naproxen is a bad example, as it contains already several points for metabolic 'attacks', i.e. a methyl-ether (directly attached to the naphthalene) and a free carboxylic group.

My point always was that in particular JWH-015 and -018 lack any feasible moieties for a fast and effective metabolism. The sole presence of a naphthalene-moiety is of course not enough. The presented data seems to support my guess, as ring hydroxylation was indeed the main observed metabolic pathway.

While the epoxide-intermediate of phenanthrene are presumably more long-lived than the ones of smaller polycycles, such a prolonged half-life doesn't seem to be necessary to do some harm, as the popular example of benzene shows. In contrary to what you stated, even small concentrations increase the risk for cancer, although I won't dare to put it into numbers. Combine this with a potential long biological half-life of the compound themselves (due to their high lipophilicity) and it gets even worse.
And by the way: The extended conjugated system of the AAIs presumably stabilizes epoxide-intermediates, and therefore, could prolong their half-life again.


I think some misunderstood my point:
I am in no way saying that the low-substituted AAIs are proved cancerogenics - I never said that! But they are potential cancerogenics, and the more info is incoming the more this idea is supported. Considering the reported amounts consumed by some folks (e.g. several grams within few weeks!), I definitively see a danger here. For this reason, I'm against the repeated appeasement-statements!

- Murphy
 
in the past someone said they thought JWH-250 would be no less toxic than naphthalene containing AAIs (ie the naphthalene moiety is a red herring) does this still hold true?

Probably. But who knows?
 
Metabolism via ring hydroxylation of the naphthyl moiety is not necessarily bad or carcinogenic, for instance see the metabolism of duloxetine. The problem is moreso with the non-etherized compounds for some reason, for instance both duloxetine and propranolol have the naphthol moieties as an ether and are not problematic (that much), but pronethalol is very carcinogenic. For some reason straight carbon chains or no carbon chains are the big problem from naphthalene, which I can't explain at the moment.


Is duloxetine metabolized via epoxide intermediaries or not, though? I assume so, but that study doesn't seem to comment on it.
 
Is duloxetine metabolized via epoxide intermediaries or not, though? I assume so, but that study doesn't seem to comment on it.

Yes. The epoxide is in the metabolic pathway in Figure 6.
 
Yeah, i should have edited my post. I came acrosss it when I gave it a closer read.
 
well being from the UK, ive stocked up, because of the 23rd Dec ban, have calmed them down, to several grams/s a month to a lot less, trying to do it wekends only, but so much synergy fun. (018!!!, 073!!, 083-nosure, 200-ok, 250!!!!) :)

Always smoke while on MJ, for its natural protective properties! Every thing we eat, drink, wear, breath all day is potientially toxic and cancerous unless you wanna live in a bubble, and do everything yourself very carefully. Which one will get you first!
 
Presumably the ether moiety of JWH-081 makes it a candidate for glucuronidation.

Yep. Although this idea remains unproved yet, the idea behind introducing more functionalities was - from a toxicological point of view - to facilitate metabolism.

- Murphy
 
For completion, I will copy the abstract of the article from UroToday.com:

Olea-Herrero N, Vara D, Malagarie-Cazenave S, Díaz-Laviada
"Inhibition of human tumour prostate PC-3 cell growth by cannabinoids R(+)-Methanandamide and JWH-015: Involvement of CB2 - Abstract"
We have previously shown that cannabinoids induce growth inhibition and apoptosis in prostate cancer PC-3 cells, which express high levels of cannabinoid receptor types 1 and 2 (CB(1) and CB(2)). In this study, we investigated the role of CB(2) receptor in the anti-proliferative action of cannabinoids and the signal transduction triggered by receptor ligation.

The human prostate cancer cell lines, namely PC-3, DU-145 and LNCaP, were used for this study. Cell proliferation was measured using MTT proliferation assay, [(3)H]-thymidine incorporation assay and cell-cycle study by flow cytometry. Ceramide quantification was performed using the DAG kinase method. The CB(2) receptor was silenced with specific small interfering RNA, and was blocked pharmacologically with SR 144528. In vivo studies were conducted by the induction of prostate xenograft tumours in nude mice.

We found that the anandamide analogue, R(+)-Methanandamide (MET), as well as JWH-015, a synthetic CB(2) agonist, exerted anti-proliferative effects in PC-3 cells. R(+)-Methanandamide- and JWH-015-induced cell death was rescued by treatment with the CB(2) receptor antagonist, SR 144528. Downregulation of CB(2) expression reversed the effects of JWH-015, confirming the involvement of CB(2) in the pro-apoptotic effect of cannabinoids. Further analysing the mechanism of JWH-015-induced cell growth inhibition, we found that JWH-015 triggered a de novo synthesis of ceramide, which was involved in cannabinoid-induced cell death, insofar as blocking ceramide synthesis with Fumonisin B1 reduced cell death. Signalling pathways activated by JWH-015 included JNK (c-Jun N-terminal kinase) activation and Akt inhibition. In vivo treatment with JWH-015 caused a significant reduction in tumour growth in mice.

This study defines the involvement of CB(2)-mediated signalling in the in vivo and in vitro growth inhibition of prostate cancer cells and suggests that CB(2) agonists have potential therapeutic interest and deserve to be explored in the management of prostate cancer.


Well, I think it is very important to make a difference between 2 not further related issues:

1. Do cannabinoids possess potentially useful pharmacological activity?
I think this can be answered with a clear YES! The above abstract is just one example of what cannabinoids can be used for. Several other indications are already exploited, like the antiemetic, analgesic and appetite-stimulating activity. And again several others are researched at the moment. As we know, even a cannabinoid-antagonist made it to the market (Rimonabant).

2. Are the low-substituted JWH-compounds potentially harmful?
Well, as explained before, this can not be answered with certainty but many indications point in exactly this direction. One must not confuse the pharmacological activity of a compound (with can in any case be very useful) with its inherent toxicity!
Talidomid was an extremely useful compound...until the teratogenic effects were discovered and the stuff was taken from the market. Still, for every non-pregnant woman or any man it remains a useful compound (if it would be available).
Rofecoxib ("Vioxx") was a tremendously useful compound...until the serious cardio-vascular sideeffects became known.
And so on.

- Murphy
 
the study is not evidence either way.

A bit of background:
It has been known for some time that selective CB-2 agonists have activity against certain cancers, for example some gliomas, and surprise surprise the CB2 agonist JWH 015 has activity. Some very selective agents have progressed to clinical trials with impressive results.

We also know that CB2 agonists in general can suppress the immune system and can cause programmed cell death in immune cells and unsurprisingly so does JWH-015 http://www.sciencedirect.com/scienc...serid=10&md5=81f45cb575787566dcb073429d74065a
along with general immune suppression. Interestingly immune suppression in general causes increased incidence of cancer.

A study on isolated prostate cells in a dish is pretty meaningless for extrapolating and generalising and bear in mind there are lots of things which have anticancer activity against some cell lines in vitro, some retain the activity in vivo some don't.

Who knows what cancers JWH compounds would cause if indeed they were carcinogens? I somehow doubt prostate cancer would be on the list.

There is a bigger picture which will be revealed by epidemiological studies of JWH users in five to ten years time. I personally doubt that the JWH compounds will be found to be carcinogenic in reasonable doses. The muppets out there burning hundreds of mg a week should get sensible, just in case.
 
the study is not evidence either way.

A bit of background:
It has been known for some time that selective CB-2 agonists have activity against certain cancers, for example some gliomas, and surprise surprise the CB2 agonist JWH 015 has activity. Some very selective agents have progressed to clinical trials with impressive results.

We also know that CB2 agonists in general can suppress the immune system and can cause programmed cell death in immune cells and unsurprisingly so does JWH-015 http://www.sciencedirect.com/scienc...serid=10&md5=81f45cb575787566dcb073429d74065a
along with general immune suppression. Interestingly immune suppression in general causes increased incidence of cancer.

I don't know that that's true about immune suppression necessarily causing increased cancer. Eicosapentaenoic acid, an omega 3 fatty acid is an immune suppressant but according to this article: "Since studies on the health of Greenland Eskimos in the 1970s, these compounds have been purported to have many health benefits when included in ones diet on a regular basis. The Eskimos eat large amounts of DHA and EPA in their diets. As all natural fish and fish oils contain both substances, learning which of them are the major contributors to the health benefits claimed for fish or fish oil has been hard, or if both are needed to produce these benefits. Epidemiological evidence suggest that populations consuming marine diets rich in the n-3 PUFA eicosapentaenoic acid (EPA) have a low incidence of cancer. A potential anti-cancer activity of EPA is further supported by in vitro and in vivo experimental studies."

Also I just found this study about cannabinoids' immune suppressant role. It says this: "Whereas this finding [of cannabinoid receptors in the immune system of a rat] has implications for human immunomodulation, it should be noted that rodents are more susceptible than humans to immunomodulation by cannabinoids, perhaps reflecting the substantially higher levels of receptor in their immune cells. In humans, immune suppression is subtle and in many cases insignificant. There is little evidence for cannabinoid immunosuppression as a causative agent in disease."
 
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