Melatonin is a naturally occurring hormone in the body that is responsible for maintaining sleep. You may already have heard of its use as a supplement to help you sleep or to help with jet lag. It is now being studied for more than just sleep functions, as it has potential as an antioxidant. Because these studies are new, be cautious when using melatonin for anything other than sleep. As with any new supplement, check with your doctor before starting.
Liver Background
The liver is an important organ in the body, functioning to protect you from toxic substances, filtering the blood and producing cholesterol. According to an article published in The Oncologist journal in April 2001, the liver utilizes a variety of enzymes to perform detoxification, following two phases to transform compounds into inert, water-soluble substances that can be excreted in the urine. The article says both phases are important and that dysfunctions in one or the other can lead to toxic substances being released into the body.
Oxidative Stress
In a study published in July 2010 in the journal Free Radical and Biology Medicine, oxidative stress was found to be compounded by a substance called asymmetric dimethylarginine (ADMA), which inhibits nitrous oxide synthase, an important part of cell structure, and is also responsible for many systemic diseases. The study found that melatonin prevented ADMA increases in rat livers. This information suggests that melatonin may be a potential therapy for different diseases with elevated cellular ADMA, but more research is needed before melatonin can be marketed for this use.
Lipid Peroxidation
Lipid peroxidation occurs in the liver and is associated with the impairment of protein functions located in the membrane environment, according to an article published in the journal Current Molecular Medicine in July 2007. Lipid peroxidation can lead to free radical damage in cells, and melatonin has been shown to help reduce peroxidation. A study that focused on melatonin and lipid peroxidation was published in June 2010 in the journal Neuro Endocrinology Letters. It found that melatonin injections prevented lipid peroxidation in lung cells, particularly peroxidation induced by potassium bromate. The study published in Current Molecular Medicine also showed that melatonin was helpful in preventing lipid peroxidation.
Liver Glycogen Levels
Glycogen is a substance stored in the liver, waiting for the body to turn it into glucose to fuel cells. It is important in the maintenance of blood sugar. The Pakistan Journal of Pharmaceutical Sciences published a study in July 2010 on melatonin's effect on glycogen and plasma glucose levels. While plasma glucose levels showed no difference, liver glycogen levels increased significantly with melatonin supplementation. This study was not performed on humans, so more information is needed before melatonin can be assumed safe for improving your liver glycogen levels.
Cautions
According to the recently mentioned article, published in Current Molecular Medicine, uses of melatonin in lab experiments do not necessarily translate to human use. It says specifically that the antioxidant capacity of melatonin in a solution is very different from its capacity in human cell situations. While this information is promising and valuable, be sure to discuss use of melatonin with your physician, who can keep you abreast of any new developments with the supplement.
References
- Free Radical and Biology Medicine; "Melatonin blocks oxidative stress-induced increased asymmetric dimethylarginine"; Tain, YL et al; July 2010
- Neuroendocrinology Letters; "Melatonin restores the basal level of lipid peroxidation in rat tissues exposed to potassium bromate in vitro"; Stasiak, M et al; June 2010
- Current Molecular Medicine; "The Ability of Melatonin to Counteract Lipid Peroxidation in Biological Membranes"; Catala, A; July 2007
- The Oncologist; "The Molecular Perspective: Cytochrome P450"; Goodsell, D, PhD; April 2001
