UVA irradiation (320-400 nm) comprises about 95 percent of incident midday solar ultraviolet irradiation. It penetrates skin much deeper than UVB irradiation. The absorption of UVA irradiation in endogenous chromophores frequently leads to the generation of reactive oxygen species such as singlet oxygen ((1)O(2)). (1)O(2) is an important biochemical intermediate in multiple biological processes...

With ultraviolet and visible light exposure, some pharmaceutical substances applied systemically or topically may cause phototoxic skin irritation. The major factor in phototoxicity is the generation of reactive oxygen species (ROS) such as singlet oxygen and superoxide anion that cause oxidative damage to DNA, lipids and proteins. Thus, measuring the generation of ROS can predict the phototoxi...

BACKGROUND Different investigation showed that 5-methoxypsoralen and 8- methoxypsoralen reduce birth rates in the rats. OBJECTIVE In this study we worked out the effect of methoxsalen together with ultraviolent A (UVA) radiation on mature Balb/C mice spermatogenesis. MATERIALS AND METHODS The LD50 standard was determined 160 mg/kg and the UVA dose which causes erythema was calculated 0.046 ...

In contrast to the immunosuppressive potential of UVB (280-320 nm) radiation in experimental animals and humans, UVA (320-400 nm) radiation at environmentally relevant doses appears to be immunologically inert. However, such exposure to UVA radiation has been observed unexpectedly to induce resistance to UVB-induced immunosuppression in mice, by a mechanism resulting in the inactivation of cis-...

purpose : to compare the protection of eyes against visible light (vl) and ultraviolet radiation (uvr) by sunglasses available through the iranian optician trade ::::union:::: (iotu) shops and those provided by miscellaneous vendors. methods : totally, 353 pairs of sunglasses, including 188 pairs from iotu shops and 165 pairs from miscellaneous vendors were selected based on systematic random s...

Oxidative stress of human skin fibroblasts by treatment with ultraviolet A (UVA) radiation has been shown to lead to an increase in levels of the heme catabolizing enzyme heme oxygenase 1 [heme, hydrogen-donor:oxygen oxidoreductase (alpha-methene-oxidizing, hydroxylating), EC 1.14.99.3] and the iron storage protein ferritin. Here we show that human skin fibroblasts, preirradiated with UVA, sust...

The aim of this study was to determine the photocatalytic effects of zinc oxide (ZnO) NPs in combination with UVA-1 in human head and neck squamous cell carcinoma (HNSCC) cell lines in vitro. NP characteristics and intracellular distribution were described by transmission electron microscopy (TEM). After pre-incubation with ZnO NPs in concentrations of 0.002-20 µg/ml, the HNSCC cell lines HLaC ...

The aim of this study was to investigate whether magnesium ascorbyl phosphate (MAP) and coenzyme Q10 (CoQ10) can protect keratinocytes against ultraviolet (UV)A irradiation by increasing the levels of glutathione (GSH). The cell survival fraction was 89.9% when the keratinocytes were irradiated with UVA at a dose of 4 J/cm2. The cell survival fractions were 48.4, 9.1 and 4.8%, at doses of 8, 16...

Ultraviolet A (UVA) irradiation plays a role in premature aging of the skin through triggering oxidative stress-associated stimulation of matrix metalloproteinase-1 (MMP-1) responsible for collagen degradation, a hallmark of photoaged skin. Compounds which can activate Nrf2, a transcription factor regulating antioxidant gene expression, should therefore serve as effective anti-photoaging agents...