Evaluation of ultraviolet-A protection by sunscreen agents using a mouse model of contact photoallergy.

Abstract

This study was conducted to investigate in vivo evaluation of protectiveness by sunscreens in the UVA range using a mouse model of contact photoallergy (CPS) to 3,3',4',5-tetrachlorosalicylanilide (TCSA). Mice were sensitized with TCSA painting plus UVA irradiation (TCSA/UVA) on the abdomen and, 5 days later, challenged with TCSA/UVA on the earlobe. Each of four sunscreen agents, benzophenone-3, Parsol 1789, p-aminobenzoic acid, and 2-ethyl-hexyl-p-methoxycinnamate, was applied to the earlobes before irradiation. Their protective efficacy was evaluated in the degree of inhibition of both ear swelling responses and TCSA-epidermal cell photoadduct formation. Two UVA-absorbing sunscreens, benzophenone-3 and Parsol 1789, dramatically inhibited the ear swelling response, while the two UVB-absorbers exhibited a much less suppressive effect. The UVA-absorbing agents functioned via inhibiting the formation of TCSA-epidermal cell photoadducts. This method is thought to be useful for in vivo estimation of UVA protection provided by sunscreens against the exquisite sensitivity involved in photoallergy.

• Authors: Y Tokura, H Yagi, H Ihda, M Takigawa
• Journal: Journal of dermatological science (J Dermatol Sci) Vol. 7 Issue 1 Pg. 39-44 (Feb 1994) ISSN: 0923-1811 [Print] Netherlands
• PMID: 8193083 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Salicylanilides
• Sunscreening Agents
• 3,3',4',5-tetrachlorosalicylanilide

Topics

• Animals
• Dermatitis, Contact (immunology, pathology, prevention & control)
• Dermatitis, Photoallergic (immunology, pathology, prevention & control)
• Epidermis (pathology)
• Mice
• Mice, Inbred BALB C
• Salicylanilides (immunology)
• Sunscreening Agents (pharmacology)
• Ultraviolet Rays