The circadian control of skin and cutaneous photodamage

Photochem Photobiol. 2012 Sep-Oct;88(5):1037-47. doi: 10.1111/j.1751-1097.2012.01099.x. Epub 2012 Feb 21.


Biologically, light including ultraviolet (UV) radiation is vital for life. However, UV exposure does not come without risk, as it is a major factor in the development of skin cancer. Natural protections against UV damage may have been affected by lifestyle changes over the past century, including changes in our sun exposure due to working environments, and the use of sunscreens. In addition, extended "day time" through the use of artificial light may contribute to the disruption of our circadian rhythms; the daily cycles of changes in critical bio-factors including gene expression. Circadian disruption has been implicated in many health conditions, including cardiovascular, metabolic and psychiatric diseases, as well as many cancers. Interestingly, the pineal hormone melatonin plays a role in both circadian regulation as well as protection from UV skin damage, and is therefore an important factor to consider when studying the impact of UV light. This review discusses the beneficial and deleterious effects of solar exposure, including UV skin damage, Vitamin D production, circadian rhythm disruption and the impact of melatonin. Understanding these benefits and risks is critical for the development of protective strategies against solar radiation.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • ARNTL Transcription Factors / genetics
  • ARNTL Transcription Factors / metabolism
  • CLOCK Proteins / genetics
  • CLOCK Proteins / metabolism
  • Circadian Rhythm / physiology
  • Circadian Rhythm / radiation effects*
  • Dehydrocholesterols / metabolism
  • Gene Expression Regulation / drug effects
  • Gene Expression Regulation / radiation effects
  • Humans
  • Melanoma / etiology
  • Melanoma / genetics
  • Melanoma / metabolism*
  • Melanoma / prevention & control
  • Melatonin / biosynthesis*
  • Melatonin / genetics
  • Risk Factors
  • Skin / drug effects
  • Skin / metabolism*
  • Skin / radiation effects
  • Skin Neoplasms / etiology
  • Skin Neoplasms / genetics
  • Skin Neoplasms / metabolism*
  • Skin Neoplasms / prevention & control
  • Sunscreening Agents / pharmacology
  • Ultraviolet Rays / adverse effects
  • Vitamin D / biosynthesis*


  • ARNTL Transcription Factors
  • ARNTL protein, human
  • Dehydrocholesterols
  • Sunscreening Agents
  • Vitamin D
  • 7-dehydrocholesterol
  • CLOCK Proteins
  • CLOCK protein, human
  • Melatonin