Melatonin: A Potential Protector from DNA Damage Caused by Exposure to Ionizing Radiation

by | Apr 27, 2011 | 2011, Environmental Health, Melatonin, Radioactivity and Irradiation

Written by Susan Sweeny Johnson, PhD, Biochem. Studies have shown melatonin supplementation could be a general protector from on-going DNA damage caused by ingested or inhaled radioisotopes. 

The Japanese people are facing a radiation exposure crisis that has drawn the world’s attention toward the health dangers of both acute and chronic radiation events. A general, safe, effective, readily available and low cost method of reducing tissue damage from exposure to radiation especially over a long period of time is highly desirable.

People can be exposed to radiation in various ways; externally via radiation generated from an external source or internally from ingesting or inhaling radioactive compounds. Some radioisotopes can be flushed from the body but many incorporate into the body’s tissue. (The latter cause prolonged exposure to ionizing radiation.) Damage can be acute where body tissues are killed or chronic where accurate DNA replication and therefore the production of new healthy cells are affected.

Some treatments used post-Chernobyl were ingestion of potassium iodide to protect the thyroid from radioactive iodine accumulation; chelation therapy to remove heavy metal radioisotopes from the body; sodium bicarbonate to treat uranium poisoning; and the use of the dye Prussian blue to help with radioactive Cesium-137 and thallium poisoning. However, all of the above treatments are specific for individual elemental radioisotopes rather than generally protecting against the variety of radioactive elements produced in a nuclear event (1).

Melatonin potentially meets these criteria. Many animal studies and human cell studies indicate that pretreatment with supplemental melatonin can reduce radiation damage up to 30% from an external exposure (2-13).  Damage was measured as unrepaired breaks in DNA and the subsequent formation of micronuclei which result from the incorrect copying of DNA during the formation of new cells.

In this article Dr. Reiter states, “Its (melatonin’s) function in reducing damage from ionizing radiation in both animals and humans is well documented [6-13,15] and its protective actions exceed those of other commonly used radioprotectors.  Melatonin has been shown to prevent the death of animals given what would normally be a lethal dose of ionizing radiation [5].”   One of the referenced studies refers to a human in vivo study where a single oral 30mg dose of melatonin was administered followed up to 2 hours later by the drawing of blood samples and consequent irradiation. The cultured blood samples showed a significant decrease in leukocyte damage between one and two hours after taking the melatonin (6).

Although human dosage is not established, the implication is that melatonin supplementation could be a general protector from on-going DNA damage caused by ingested or inhaled radioisotopes. One rat study successfully used a series of five injections of 15mg melatonin/kg body weight (14). Another used five injections of 2.5mg/kg pretreatment (15).  As the efficacy of melatonin in humans is characterized, effective dosage should be established.

Source: Reiter, Russel J., et al. “The disaster in Japan: utility of melatonin in providing protection against ionizing radiation.” Journal of pineal research 50.4 (2011): 357-358.

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Posted April 27, 2011.

References:

  1. Wolbarst AB, Wiley AL Jr, Nemhauser JD, Christensen DM, Hendee WR. Medical Response to a major radiologic emergency: a primer for medical and public health practioners. Radiology 2010;254:660-677.
  2. Das B, Bennett PV, Cutler NC, Sutherland JC Sutherland BM. Melatonin Protects human cells from clustered damages, killing and acquisition of soft agar growth induced by X-rays or 970 MeV/n Fe ions. Int J Radiat Biol, PUBMED:21401316.
  3. Monobe M, Hino M, Sumi M et al. Protective effect of melatonin on gamma-radiation induced intestinal damage. Int J Radiat Bio. 2005:81:855-860.
  4. El-Missiry MA, Fayed TA. El-Sawi MR, El-Sayed AA. Ameliorative effect of melatonin against gamma-radiation-induced oxidative stress and tissue injury. Ecotoxicol Environ Saf 2007; 66:278-286.
  5. Vijayalaxmi, Meltz ML, Reiter RJ, Herman TS,  Kumar KS. Melatonin and protection from whole-body irradiation: survival studies in mice. Mutat Rs 1999; 425:21-27.
  6. Vijayalaxmi, Reiter RJ, Herman TS, Meltz ML. Melatonin and radioprotecton from genetic damage: in vivo/in vitro studies with human volunteer. Mutat Res 1996; 37:221-228.
  7. Vijayalaxmi, Reiter RJ, Herman TS, Meltz ML, Melatonin reduces gamma-radiation-induced primary DNA damage in human blood lymphocytes. Mutat Res 1998;347:203-208.
  8. Vijayalaxmi, Thomas CR Jr,  Reiter  RJ, Herman TS. Melatonin: from basic research to cancer treatment clinics. J Clin Oncol 2002; 20:2575-2601.
  9. Koc M. Taipi S, Erin Buyukokurglu M, Bakan N. The effect of melatonin against oxidative damage during total-body irradiation in rats. Radiat Rs 2003; 160:251-255.
  10. Undeger U, Giray B, Zorlu AF, Oge K, Bacaran N. Protective effects of melatonin on ionizing radiation induced DNA damage in the rat brain. Exp Toxicol Pathol 2004; 55:379-384.
  11. Vijayalaxmi, Reiter RJ, Tan DX, Herman TS, Thomas CR Jr. Melatonin as a radioprotective agent: a review. Int J Radiant Oncol Biol Phys 2004; 59:639-653.
  12. Manda K, Ueno M, Anzai K. AFMK,  a melatonin metabolite, attentuates X-ray-induced oxidative damage to DNA, proteins and lipids in mice. J Pineal Res 2007; 42:386-393.
  13. Shirazi A, Ghobadi G, Ghazi-Khansari M. A radiobiological review on melatonin: a novel radioprotector. J Radiat Res 2007; 48:236-272.
  14. Topkan E,Tufan H, Yavuz AA et al. Comparison of the protective effects of melatonin and amifostine on radiation induced epiphyseal injury. Int J Radiat Biol 2008; 84:796-802.
  15. Assayed ME, Abd El-Aty AM. Protection of rat chromosomes by melatonin against gamma radiation induced damage. Mutat Res 2009; 677:14-20.
  16. Vijayalaxmi, Meltz ML, Reiter RJ, Herman TS,  Kumar KS. Melatonin and protection from whole-body irradiation: survival studies in mice. Mutat Rs 1999; 425:21-27.