Protective Effects of Pyridoxamine Against UVC-induced Programmed Cell Death in HaCaT Cells.

BACKGROUND: Exposure to ultraviolet (UV) light is closely related to human diseases, such as skin cancer, due to irreversible injuries to the skin cells. The UV-induced DNA damage and programmed cell death are important determinants for skin carcinogenesis. The aim of the present study was to investigate the anti-ultraviolet-C (UVC) effects of pyridoxamine in human keratinocyte HaCaT cells and its mechanisms of action. RESULTS: UVC-induced programmed cell death in HaCaT cells was abrogated by treated the cells immediately after UVC irradiation with 40, 80 and 160 µM of pyridoxamine. Monitoring the UVC-induced-specific reactive oxygen species, we found that 20, 40, 80 and 160 µM of pyridoxamine was also effective in suppressing the induction of reactive oxygen species by UVC. CONCLUSION: Overall, our results provided evidence showing that pyridoxamine was effective in protecting HaCaT cells from UVC-induced programmed cell death and may be a potential anti-UVC agent in life and clinical practice.

Baicalin scavenges reactive oxygen species and protects human keratinocytes against UVC-induced cytotoxicity.

Long-term exposure to solar ultraviolet (UV) radiation can cause multiple skin disorders, including skin cancer. Protection against UV-induced damage is, therefore, a worldwide concern. Baicalin, a major component of traditional Chinese medicine Scutellaria baicalensis, has been reported to have antioxidant and cytostatic effects on normal epithelial and normal peripheral blood and myeloid cells. In the current study, we examined whether baicalin could also effectively protect human keratinocytes from damaging short-wave UVC irradiation. Baicalin-scavenged reactive oxygen species increased within 2 h after UVC radiation. Baicalin also abrogated UVC-induced apoptosis. In addition, we identified the major products after UVC radiation with T4 UV endonuclease, finding that baicalin prevented cyclobutane pyrimidine dimer formation induced by UVC. Furthermore, baicalin also prevented formation of oxidative adducts induced by UVC. Our results demonstrated the utility of baicalin in assessing the potential contribution of traditional Chinese medicinal agents in therapy of UVC-induced genomic damage to skin and suggest potential application of these agents as pharmaceuticals in prevention of solar-induced skin damage.