Pyridoxine toxicity to cultured fibroblasts caused by near-ultraviolet light.

Abstract

Pyridoxine, like riboflavin, has absorption in the range of near ultraviolet (UVA; 320-400 nm) radiation and is known to decompose after long irradiation with germicidal lamps. Thus, the possibility of UVA-induced pyridoxine photosensitization was studied in cultured normal human, hydroa vacciniforme, and xeroderma pigmentosum fibroblasts. Cytotoxicity caused by the sensitization was measured by post-UVA colony formation. Pyridoxine showed strong cytotoxic effect after UVA radiation and the effect remained for at least 60 min after UVA radiation. Although the cytotoxicity decreased a little when pyridoxine was irradiated under anaerobic conditions, the amount of hydrogen peroxide produced by UVA radiation was hardly cytotoxic and the rate of photodecomposition of pyridoxine was slower under anaerobic conditions than aerobic ones. Thus, the toxicity seemed to depend mostly on the photoproducts of pyridoxine. The UVA-induced pyridoxine cytotoxicity was not due to DNA damage that is to be excision-repaired because group A and C xeroderma pigmentosum fibroblasts were killed as in the case of normal human fibroblasts.

• Authors: K Sato, H Taguchi, T Maeda, K Yoshikawa
• Journal: The Journal of investigative dermatology (J Invest Dermatol) Vol. 100 Issue 3 Pg. 266-70 (Mar 1993) ISSN: 0022-202X [Print] United States
• PMID: 8440902 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Hydrogen Peroxide
• Horseradish Peroxidase
• Pyridoxine

Topics

• Absorption (drug effects)
• Aerobiosis
• Anaerobiosis
• Cell Death (drug effects)
• Cell Line
• Clone Cells (drug effects)
• Dose-Response Relationship, Drug
• Dose-Response Relationship, Radiation
• Energy Metabolism
• Fibroblasts (cytology, radiation effects)
• Horseradish Peroxidase (pharmacology)
• Humans
• Hydrogen Peroxide (metabolism)
• Hydrogen-Ion Concentration
• Pyridoxine (radiation effects, toxicity)
• Time Factors
• Ultraviolet Rays