Enhanced expression of matrix metalloproteinase (MMP)-1/interstitial collagenase and MMP-3/stromelysin-1 in skin fibroblasts and subsequent damage of dermal connective tissue in the context of sun-induced premature aging and skin tumour progression is causally linked to UVB irradiation. Here, we were interested in identifying components of the complex signal-transduction pathway underlying UVB-...

UV radiation plays an important role in the induction of cutaneous malignancy, including basal cell and squamous cell carcinomas and malignant melanoma. In addition to its effects on DNA damage and repair mechanisms, UV radiation has been shown to modulate the expression of specific genes, altering the levels of their mRNAs and the synthesis of their corresponding proteins. In order to gain fur...

UV radiation plays an important role in the induction of cutaneous malignancy, including basal cell and squamous cell carcinomas and malignant melanoma. In addition to its effects on DNA damage and repair mechanisms, UV radiation has been shown to modulate the expression of specific genes, altering the levels of their mRNAs and the synthesis of their corresponding proteins. In order to gain fur...

Exposure to ultraviolet-B (UVB) radiation induces inflammation and photocarcinogenesis in mammalian skin. Docosahexaenoic acid (DHA), a representative ω-3 polyunsaturated fatty acid, has been reported to possess anti-inflammatory and chemopreventive properties. In the present study, we investigated the molecular mechanisms underlying the inhibitory effects of DHA on UVB-induced inflammation in ...

The deleterious effects of ultraviolet radiation on human skin are via inducing inflammation, immunosuppression, premature skin aging and carcinogenesis. As the most energetic component of ultraviolet radiation reaching the earth’s surface, UVB radiation induces DNA damage and is a critical carcinogenic factor in skin carcinogenesis. However, UVB irradiation may trigger apoptosis and/or cell de...

Exposure of skin to UVB radiation (290-320 nm) modulates the immune system, with most studies showing a suppression of Th1-driven immune responses. This study investigated the effects of UVB on Th2-associated immune responses using a murine model of allergic respiratory inflammation. C57BL/6, histamine receptor-1 knockout (H1RKO), and histamine receptor-2 knockout (H2RKO) mice were exposed to a...

BACKGROUND The fermented leaves and stems of Cyclopia intermedia are used to brew honeybush tea, a herbal tea indigenous to South Africa. The aim of this study was to evaluate the protective effect of fermented honeybush extracts (FH ex) and scale-up fermented honeybush extracts (SFH ex) against ultraviolet B (UVB)-induced damage in HaCaT keratinocytes. To this end, we examined UVB-induced cell...

Different strains of mice have varying susceptibilities to ultraviolet radiation (UV) of wavelength 280-320 nm (UVB) for 50% suppression of systemic contact hypersensitivity (CHS) responses. Prevalence of histamine-staining dermal mast cells in different strains of mice (C57BL/ 6J, DBA/2, BALB/c) correlated directly with their susceptibility to UVB-induced systemic immunosuppression. BALB/c mic...

We have shown previously that dietary grape seed proanthocyanidins (GSPs) inhibit UVB-induced photocarcinogenesis in mice. As UVB-induced immune suppression has been implicated in the development of skin cancer risk, we investigated whether dietary GSPs can modulate the effects of UVB on the immune system. We found that the UVB-induced (180 mJ/cm2) ear swelling response (inflammatory reaction) ...