Melatonin: A Powerful Cancer-Stopping Molecule
While our bodies produce melatonin in the pineal gland, this molecule is present throughout the body. And despite its association with sleep because of its support of our natural light and dark circadian rhythms, it may be a potent cancer preventer, and a powerful co-treatment with cancer-fighting drugs.
Initial research with melatonin considered that its antioxidant actions were helping to ferret out and scavenge free radicals that damage DNA and kick start tumor growth. Damage to DNA, because of oxidative stress, can have a cumulative effect over a lifetime and make a person more prone to developing cancer.
In addition to the ability of melatonin to protect healthy cells, it prevents cancer from spreading throughout the body by denying it access to blood vessels. It also has direct actions on cancer cells, making them more easily controlled with conventional chemotherapy drugs, and reduces the toxic side effects of those drugs on patients. This means that something as simple as melatonin could be readily used as an adjunct therapy along with standard medications, making them more effective while stopping cancer cells from becoming resistant.
Reiter RJ, Rosales-Corral SA, Tan DX, et al. Melatonin, a Full Service Anti-Cancer Agent: Inhibition of Initiation, Progression and Metastasis. Int J Mol Sci. 2017;18(4):843.
There is highly credible evidence that melatonin mitigates cancer at the initiation, progression and metastasis phases. In many cases, the molecular mechanisms underpinning these inhibitory actions have been proposed. What is rather perplexing, however, is the large number of processes by which melatonin reportedly restrains cancer development and growth. These diverse actions suggest that what is being observed are merely epiphenomena of an underlying more fundamental action of melatonin that remains to be disclosed. Some of the arresting actions of melatonin on cancer are clearly membrane receptor-mediated while others are membrane receptor-independent and involve direct intracellular actions of this ubiquitously-distributed molecule. While the emphasis of melatonin/cancer research has been on the role of the indoleamine in restraining breast cancer, this is changing quickly with many cancer types having been shown to be susceptible to inhibition by melatonin. There are several facets of this research which could have immediate applications at the clinical level. Many studies have shown that melatonin's co-administration improves the sensitivity of cancers to inhibition by conventional drugs. Even more important are the findings that melatonin renders cancers previously totally resistant to treatment sensitive to these same therapies. Melatonin also inhibits molecular processes associated with metastasis by limiting the entrance of cancer cells into the vascular system and preventing them from establishing secondary growths at distant sites. This is of particular importance since cancer metastasis often significantly contributes to death of the patient. Another area that deserves additional consideration is related to the capacity of melatonin in reducing the toxic consequences of anti-cancer drugs while increasing their efficacy. Although this information has been available for more than a decade, it has not been adequately exploited at the clinical level. Even if the only beneficial actions of melatonin in cancer patients are its ability to attenuate acute and long-term drug toxicity, melatonin should be used to improve the physical wellbeing of the patients. The experimental findings, however, suggest that the advantages of using melatonin as a co-treatment with conventional cancer therapies would far exceed improvements in the wellbeing of the patients.