S-adenosylmethionine is a metabolically active product of the essential sulfur-containing amino acid methionine. It serves as a significant methyl group donor in the human body, being involved in the synthesis of adrenaline and acetylcholine, for example, and also in various detoxification reactions.
What is S-adenosylmethionine?
S-adenosylmethionine is used in Alzheimer’s therapy, for example. S-adenosylmethionine, known as SAM or AdoMet for short, was first discovered and described by Italian Giulio Cantoni in 1952. Living cells can produce the active key product themselves, although in humans production and further processing take place primarily in the liver. In total, more than 40 metabolic reactions are known in which SAM is involved. In all these reactions, the methyl group of S-adenosylmethionine is transferred to other substances. These nucleic acids, proteins and lipids in turn change their chemical properties as a result, such as their water solubility. In order to produce S-adenosylmethionine, the body needs folic acid and vitaminB12 in sufficient quantities.
Pharmacological effect
Cells form SAM from the amino acid methionine and the nucleotide ATP with the help of the enzyme methionine adenosyl transferase. The highly reactive methyl group of S-adenosylmethionine can now be transferred to a wide variety of metabolic products by means of enzymatic reactions. Thus, S-adenosylmethionine plays a crucial role in the formation of numerous neurotransmitters and hormones. But the transfer of SAM’s methyl group is also necessary for the synthesis of lecithins, which are a crucial component of all cell membranes. Similarly, the compound helps cells inactivate certain parts of the genetic material by transferring its methyl group to DNA. The energy-rich creatine of the muscles is also formed with the help of the methyl group transfer of S-adenosylmethionine. On the other hand, a SAM-dependent enzyme inactivates the tissue hormone histamine, which plays a decisive role in allergic reactions, among other things. SAM also promotes the formation of the body’s own glutathione. This antioxidant protects the cells from various harmful substances. Numerous toxic substances are also rendered harmless to the body by transferring the methyl group of S-adenosylmethionine directly to them. This makes the previously lipophilic toxins water-soluble and they can be easily excreted in the urine or stool. If the active ingredient S-adenosylmethionine releases its methyl group, it is itself converted into S-adenosylhomocysteine, and subsequently into adenosine and homocysteine. Subsequently, homocysteine can be changed back to methionine or to the amino acid cysteine in another reaction.
Medical application and use
It is true that healthy people can produce SAM themselves in sufficient quantities from the sulfur-containing amino acid methionine. But there are diseases in which this endogenous production seems to be disturbed: in Alzheimer’s disease, for example, a comparatively low endogenous amount of S-adenosylmethionine can often be detected. Taking the drug is supposed to compensate for this deficiency. In the treatment of depression, the active ingredient increases serum levels of serotonin and dopamine, among other things. SAM is also used in various liver diseases because it improves detoxification. Arthritis patients particularly appreciate the analgesic effect of the drug. S-adenosylmethionine is also approved as a dietary supplement in tablet form in many countries. Since the body’s own production of the active ingredient decreases with age, SAM taken orally is intended to compensate for a possible deficiency. Simultaneous intake of vitamin B12, vitamin B6, and folic acid is recommended.
Risks and side effects
In general, S-adenosylmethionine is well tolerated. However, people with bipolar disorder may develop manic symptoms from taking the drug. This can occur even in patients who were not previously known to have bipolar disorder. Cognitive dysfunction, in particular, may then persist even after discontinuation of the drug. Other side effects that may occur, especially at high doses, include stomach upset, bloating, diarrhea, and headache. Increased anxiety and allergic reactions have also been reported. To avoid possible sleep disturbances, it is recommended to take it in the morning.The effects of long-term use of the drug are not yet known. SAM should not be taken at the same time as other drugs that affect the serotonin system. Otherwise, a serotonergic syndrome may develop. When interacted with antidepressants, side effects may also increase.