Chromatography Investigates Melatonin in Health Foods

The body’s internal clock - our circadian rhythm - controls our sleep/wake cycle. It does this by using - amongst other things - a natural hormone, melatonin (MT), that is produced in the brain. Levels of melatonin change in response to the time of day, whether it is light or dark, and these changes work with your body’s natural circadian rhythm to tell us it is time to go to bed.

But, there is evidence that melatonin has been added to some health foods to hopefully improve their efficacy. Too much additional melatonin is not healthy, and so researchers are developing methods to analyse melatonin levels in various health foods. A recent paper in the journal Food and Agricultural Immunology - Development of a low-cost, simple, fast and quantitative lateral-flow immunochromatographic assay (ICA) strip for melatonin in health foods - has utilised chromatography to devise a reliable method of melatonin analysis.

Sleep hormone tells you to slow down

Melatonin is produced in the pineal gland in our brains, but is found throughout the body in our stomachs, eyes and bone marrow. It is commonly referred to as the sleep hormone, although melatonin doesn’t actually send you to sleep. Melatonin helps to regulate our body’s temperature, hormone levels and blood pressure. And as darkness falls outside, the body’s natural melatonin levels start to rise, signalling that it is time to sleep. Some people don’t or cannot make enough melatonin. Then, melatonin supplements could be the answer.

Too much melatonin - chromatography investigates

 Melatonin supplements are used by people to improve their quality of sleep including, insomnia, jet lag, shift work disturbances and sleep-wake cycle disturbances. Melatonin is also useful in circadian rhythm disorders in people who are blind. But melatonin can also have side effects, leading to nightmares, hypotension, nausea and headaches. It can also interact with other medications.

Therefore, it is important that people who are taking health supplements to aid sleep know if they are taking melatonin or not. Some health supplements have been found to contain illegal quantities of melatonin - to help the product’s efficacy. This can potentially cause health problems for people who unwittingly take a supplement containing melatonin.

In the research mentioned above, Chinese researchers have developed an easy to use immunochromatographic assay (ICA) for melatonin and validated the method using liquid chromatography. Method development in chromatography is the topic of the article, The Role of Methanol and Acetonitrile as Organic Modifiers in Reversed-phase Liquid Chromatography. The method developed by the team is described as: ICA can be potentially employed as an on-site, rapid and effective tool for screening of MT in a large number of health food samples.