Endogenous UVA chromophores may act as sensitizers of oxidative stress underlying cutaneous photoaging and photocarcinogenesis, but the molecular identity of non-DNA key chromophores displaying UVA-driven photodyamic activity in human skin remains largely undefined. Here we report that 6-formylindolo[3,2-b]carbazole (FICZ), a tryptophan photoproduct and endogenous high-affinity aryl hydrocarbon...

introduction:   palmoplantar psoriasis could hardly be differentiated from chronic tylotic eczema both clinically and histologically. the most commonly used therapeutic options for palmoplantar psoriasis are long-term therapy with topical corticosteroids and local puva. frequently, it is a recalcitrant disease. we investigated the efficacy and tolerability of the combination of topical calcipot...

UVA radiation plays an important role for adverse reactions in human tissue. UVA penetrates epidermis and dermis of skin being absorbed by various biomolecules, especially endogenous photosensitizers. This may generate deleterious singlet oxygen (O2) that oxidizes fatty acids in cell membranes, lipoproteins, and other lipid-containing structures such as the epidermal barrier. Indications exist ...

Retinyl palmitate (RP), a storage form of vitamin A, is frequently used as a cosmetic ingredient, with more than 700 RP-containing cosmetic products on the U.S. market in 2004. There are concerns for the possible genotoxicity and carcinogenicity of RP when it is exposed to sunlight. To evaluate the photomutagenicity of RP in cells when exposed to ultraviolet A (UVA) light, L5178Y/Tk+/- mouse ly...

BACKGROUND The causative link between UV exposure and melanoma development is well known, however the mechanistic relationship remains incompletely characterised. UVA and UVB components of sunlight are implicated in melanomagenesis; however the majority of studies have focused on the effects of UVB and UVC light. Interestingly, melanoma tumour sequencing has revealed an overrepresentation of mu...

We thank Jui-Teng Lin for his interest in our recent work studying riboflavin (RF)-UVA–assisted corneal collagen crosslinking (CXL). His comments on our data with a mathematic equation bring new perspectives to the corneal CXL biology. Since RF-UVA CXL emerged as a medical alternative to treat corneal ectatic disorders, efficacy and safety have been the central topics for laboratory and clinica...

Cyanobacteria are aquatic photosynthetic microorganisms. While of enormous ecological importance, they have also been linked to human and animal illnesses around the world as a consequence of toxin production by some species. Cylindrospermopsis raciborskii, a filamentous nitrogen-fixing cyanobacterium, has attracted considerable attention due to its potential toxicity and ecophysiological adapt...