6-methyluracil

[jackintheboxes]

I'm no scientist but have been doing some reading about this compound as I'm interested in the muscle fibre recovery aspect of this compound, I understand that this compound is uracil with a methyl (CH3) group at the sixth carbon, Does this mean that it is toxic to the liver, Also Ive googled but don't understand all of the medical and scientific jargon, in laymans terms how can this product aid a sportsman?

[Androcles]

Here is what it says about toxicity on one of the manufacturers sites! If you want to eat this stuff, I suggest you get your head tested first!

Safety Profile
Moderately toxic by ingestion. Questionable carcinogen with experimental neoplastigenic and teratogenic data. Experimental reproductive effects. When heated to decomposition it emits toxic fumes of NOx.

Hazard Codes : Xn(Harmful)
Risk Statements: 62-63 (Possible risk of impaired fertility;Possible risk of harm to the unborn child)
Safety Statements : 36/37/39-45-36/37 (Wear suitable protective clothing, gloves and eye/face protection ;In case of accident or if you feel unwell, seek medical advice immediately (show label where possible);Wear suitable protective clothing and gloves)

http://www.lookchem.com/6-METHYLURACIL/

[jackintheboxes]

Thanks for the reply androcles, but it seems that this product has already been cleared for human consumption and there has been many studies and tests on its ability to preform faster healing within the body especially burns as I've found out on google though your quote of ''(Possible risk of impaired fertility;Possible risk of harm to the unborn child) Is worrying.

[Androcles]

I think you will find it has been used in micro quantities as a drug, not as a food supplement! Even some of the bodybuilder sites are a bit wary from what I have read, and those guys will often try absolutely anything, passed safe or not. The references I gave are mentioned in several places as to its impact on fertility and the foetus.

I am no expert in this field but I can see no references to it being passed fit for human consumption on the Committee for Toxicity website or the CSM. Maybe you need to try the FDA in the US?

[jackintheboxes]

Thanks Androcles the foetus Implys unsafe for women but does the fertility worries apply to male or females?

[theprof]

jackintheboxes, I think it's time we laid this to rest once and for all as there seems to be continuing confusion on AB and the web about 6-methyluracil.

6-methyluracil is usually more correctly known as 2,4-dihydroxy-6-methylpyrimidine although there are a few other synonyms for the compound including, confusingly for the layman, 4-methyluracil. The molecular formula for the compound is C5H6N2O2 and it has the CAS identification code 626-48-2

Now let's discuss the toxicity of the compound. First of all, an often used method of "measuring" toxicity is by establishing what's called the median lethal dose. So how do you define a median lethal dose? Well if you consider a given group of subjects under test, the median lethal dose is the dosage required to kill exactly half of the group during a specified time period. I won't define this further as I'm trying to avoid getting too technical about it, but the only other thing you need to know is that the median lethal dose is usually abbreviated to "LD50" ie lethal dose for 50%.

Now let's move on. I'll give you the LD50 for a rodent and a mammal. In the rat, the LD50 for 6-methyluracil is 64.5 grams per Kg of body weight. In mammals (humans are in here too), the LD50 for 6-methyluracil is 2 grams per Kg of body weight.

(continued)

[theprof]

So what does this mean? Well, simply put, 6-methyluracil is toxic to humans. Oral consumption of the compound initially causes changes in the pH of stomach acid due to the alkalinity of the compound. Gastric irritation is commonplace . It's officially classified as moderately toxic by ingestion. There are also academic papers in existence that claim that it is a carcinogen and that it is a neoplastigen ie it can promote tumour growth. It is a known teratogen ie a substance that can malform an embryo or foetus.

The toxicity pathway for 6-methyluracil show that it is indeed toxic to the liver but it’s also particularly toxic to the kidneys and brain as well.

Laboratory Health& Safety regulations state that this compound can only be handled by those wearing suitable gloves and protective clothing. One of the reasons for this is that 6-methyluracil is suspected of causing infertility in human males and females.

6-methyluracil has not been cleared by the FDA in the US nor by the multitude of UK watchdog organisations. I suggest you disregard the pseudoscientific rubbish that I’ve read this evening on the various bodybuilding forums (including its apparent “harmlessness” to non-fertile women) and forget about consuming 6-methyluracil if you value your health. The fact that you are male is of little significance – it’s still toxic to your body.

Finally, the standard text on toxicity of chemicals is called “Sax’s Dangerous Properties of Industrial Materials”. The book will verify the information I’ve provided if anyone’s still in doubt. It’s currently in the 11th edition.

[Androcles]

Thank you, Prof, for the definitive answer - you confirm my inexpert suspicions!

[theprof]

Incidentally, I didn't make clear that while rats are indeed mammals, for a number of biological reasons, they are not treated as mammals as far as toxicity is concerned.Rodent susceptibility to toxins is often very different to other mammals.

[theprof]

Thanks Androcles.

[AlanBStard]

You can assign an LD50 to anything, it does not say anything about toxicity unless it's rather small. Reproductive toxicity is also very generic concept and often only applies to those trying to conceive. I hope there are actual published studies on this, not just speculations in a textbook. Unfortunately I have not managed to find anything substantial. Then again I don't have paid access to databases. What little I have found suggests possible anti-cancerous effect. It does seem to promote survival of damaged cells massively and this may be pro-cancer, on the other hand.


Orotic acid or 6-methyluracil (vide infra), when administered to rabbits with myocardial infarction induced by ligation of the anterior descending branch of the left coronary artery, can decrease the incidence of necrosis and increase the rate of regeneration for healthy cellular and fibrous connective tissue in the infarct region [182]. - http://www.ncbi.nlm.nih.gov/pubmed/5240287
/.../
However, the toxic action of the antibiotics oxacillin and levomyectin is potentiated in the presence of 6-methyluracil [268].
When administered into the newly developed chicken embryo. 6-methyluracil was found to possess strong teratogenic activity. The compound produces abnormalities in 85 per cent of the embryos at 4 mg/kg [270|. In pregnant rats this pyrimidine causes damage to 10-day-old embryos. Microanatomies! examination reveals urogenital system abnormalities (e.g. hydronephrosis, uretal oedema) [271].
Daily oral administration of 6-methyluracil to rats during increased motor activity (experimental training) induces adaption, i.e.. this pyrimidine increases the myosin and glycogen content and promotes the activities of hexokinase, UDP-glucose-glycogensynthetase and phosphorylase, hence it renders more economical expenditure

[AlanBStard]

/cont-d/
Daily oral administration of 6-methyluracil to rats during increased motor activity (experimental training) induces adaption, i.e.. this pyrimidine increases the myosin and glycogen content and promotes the activities of hexokinase, UDP-glucose-glycogensynthetase and phosphorylase, hence it renders more economical expenditure of glycogen during muscular work and more rapid resynthesis during rest [272].
Gastric ulcers induced in rats by repeated administration of caffeine can be reduced by the administration of 6-methyluracil. Treatment is more effective when this compound is combined with either 2-methyl-4,6-dihydroxypyrimidine or cytosine [273). In a study of the influence of 6-methyluracil and uracil on experimental blastomogenesis in mice, it was found that 6-methyluracil reduces the frequency of urethan-induced lung adenoma whereas uracil increases the instances [274). 6-Methyluracil, like orotic acid, can restore experimentally induced infarction in rabbits [179—182].

[AlanBStard]

http://books.google.c...ge&q="6-methyluracil" %2Bviral