Changes in ultraviolet B radiation-induced DNA damage and erythema after oral nicotinamide and polypodium leucotomos in healthy volunteers: an intraindividual controlled trial

Faisal A

Published in Photochemical & Photobiological Sciences

Methodology

Intraindividual controlled randomised trial; healthy volunteers received oral nicotinamide or Polypodium leucotomos for 4 weeks with standardised UVB challenge, minimal erythema dose measurement and skin biopsies for DNA damage assessment.

Key Findings

In 47 healthy volunteers, 4 weeks of oral Polypodium leucotomos significantly reduced UVB-induced erythema compared with control but did not measurably reduce epidermal DNA damage (cyclobutane pyrimidine dimers); oral nicotinamide reduced neither erythema nor DNA damage.

Conclusions

PL reduced UVB-induced erythema but had no measurable effect on DNA damage. NAM did not provide protection against erythema or DNA damage.

Limitations

Short 4-week exposure; small sample; intraindividual design limits generalisation to real-world sun exposure; biopsy-based DNA damage markers are surrogate endpoints, not skin cancer outcomes.