Related Experiment Video
Updated: Aug 3, 2026

Pharmacologic Induction of Epidermal Melanin and Protection Against Sunburn in a Humanized Mouse Model
Published on: September 7, 2013
Potential protection of skin by acute UVA irradiation--from cellular to animal models
1Department of Pharmacy and Pharmacology University of Bath, BA2 7AY, UK. R.M.Tyrrell@bath.ac.uk
Abstract:
The UVA (320-380 nm) component of sunlight has oxidizing properties which may be deleterious to skin cells and tissue but can also lead to the strong up-regulation of the heme-catabolizing enzyme, heme oxygenase-1. This enzyme has well-established antioxidant actions in cells as well as anti-inflammatory properties in mammals. There is also evidence from rodent models that this enzyme is responsible for the UVA-mediated protection against UVB-induced immunosuppression that occurs in skin. The relevance of these findings to acute and chronic effects of sunlight including skin carcinogenesis is currently under investigation as are the potential implications for sunlight protection in humans.
Related Concept Videos
Mutations
Chromosomal Alterations Are Large-Scale Mutations
While point mutations are changes in a single nucleotide in...
Nucleotide Excision Repair
Cells are regularly exposed to mutagens—factors in the environment that can damage DNA and generate mutations. UV radiation is one of the most common mutagens and is estimated to introduce a significant number of changes in DNA. These include bends or kinks in the structure, which can block DNA replication or transcription. If these errors are not fixed, the damage can cause mutations, which in turn can result in cancer or disease depending on which sequences are...
Pigmentation
Melanin occurs in two primary forms: eumelanin that provides black and brown pigment and pheomelanin that provides red color. Dark-skinned individuals produce more melanin than those with pale...
Skin Cancer
Basal Cell Carcinoma (BCC): BCC is the most common type of skin cancer, accounting for about 80% of cases. It typically develops in...

