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From The December 2001 Issue of Nutrition Science News
Can Melatonin Put Tumors To Sleep?
Anthony Almada
Almost a decade ago, many people were mesmerized by the promise that melatonin could lull them to sleep safely and naturally as well as jettison jet lag.1 The body's natural melatonin levels are regulated by the amount, duration, and specific form of light exposure; scientists now believe that optimal light exposure may be a critical element in maintaining natural body rhythms.2,3
Melatonin, shown to have notable anticancer effects both in the test tube and in animal studies,4-6 has now made its way into the clinic. In one study of 24 premenopausal women with metastatic breast cancer in armpit lymph nodes, scientists at Thomas Jefferson University in Philadelphia observed a significant natural melatonin increase upon completion of an initial combination chemotherapy cycle.7 The study's authors postulated that increased melatonin could have been the result of a positive response to chemotherapy. In 20 subjects with advanced non-Hodgkin's lymphoma, a therapeutic regimen that included a high dose of 10 mg melatonin twice/daily resulted in a high percentage of favorable treatment responses.8Given this promising data, more research on the role of melatonin in tumor biology is warranted.
Anthony Almada is a nutritional and exercise biochemist and has collaborated on more than 50 university-based clinical trials. He is the co-founder of EAS and founder and chief scientific officer of IMAGINutrition, based in Laguna Niguel, Calif.
References
1. Nowak JZ, Zawilska JB. Melatonin and its physiological and therapeutic properties. Pharm World Sci 1998;20:18-27.
2. Brainard GC, et al. Action spectrum for melatonin regulation in humans: evidence for a novel circadian photoreceptor. J Neurosci 2001;21:6405-12.
3. Stevens RG, Rea MS. Light in the built environment: potential role of circadian disruption in endocrine disruption and breast cancer. Cancer Causes Control 2001;12:279-87.
4. Karbownik M, et al. Anticarcinogenic actions of melatonin that involve antioxidative processes: comparison with other antioxidants. Int J Biochem Cell Biol 2001;33:735-53.
5. Xi SC, et al. Inhibition of androgen-sensitive LNCaP prostate cancer growth in vivo by melatonin: association of antiproliferative action of the pineal hormone with mt1 receptor protein expression. Prostate 2001 Jan 1;46(1):52-61.
6. Dai J, et al. Transcriptional repression of RORalpha activity in human breast cancer cells by melatonin. Mol Cell Endocrinol 2001;176:111-20.
7. Kajdaniuk D, et al. Influence of adjuvant chemotherapy with cyclophosphamide, methotrexate and 5-fluorouracil on plasma melatonin and chosen hormones in breast cancer premenopausal patients. J Clin Pharm Ther 2001;26:297-301.
8. Todisco M, et al. Cyclophosphamide plus somatostatin, bromocriptin, retinoids, melatonin and ACTH in the treatment of low-grade non-Hodgkin's lymphomas at advanced stage: results of a phase II trial. Cancer Biother Radiopharm 2001;16:171-7.
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