Several standard in vitro assays were performed in order to determine the potential antioxidant capabilities of purified aqueous extracts of the mycosporine-like amino acids (MAAs), porphyra-334 plus shinorine (P-334 + SH), isolated from the red alga Porphyra rosengurttii, asterina-330 plus palythine (AS-330 + PNE), from the red alga Gelidium corneum, shinorine (SH), from the red alga Ahnfeltiopsis devoniensis, and mycosporine -glycine (MGly), isolated from the marine lichen Lichina pygmaea. The scavenging potential of hydrosoluble radicals (ABTS + decolorization method), the antioxidant activity in lipid medium (β-carotene/ linoleate bleaching method) and the scavenging capacity of superoxide radicals (pyrogallol autooxidation assay) were evaluated. In terms of scavenging of hydrosoluble radicals, the antioxidant activity of all MAAs studied was dose-dependent and it increased with the alkalinity of the medium (pH 6 to 8.5). M-Gly presented the highest activity in all pH tested; at pH 8.5 its IC 50 was 8-fold that of L-ascorbic acid (L-ASC) followed by AS-330 + PNE while P-334 + SH and SH showed scarce activity of scavenging of hydrosoluble free radicals. AS-330 + PNE showed high activity for inhibition of β-carotene oxidation relative to vitamin E and superoxide radical scavenging whilst the activity of P-334 +SH and SH were moderate. According to these results, the potential of MAAs in photoprotection can be considered high due to a double function: (1) UV chemical screening with high efficiency for UVB and UVA regions of the solar spectrum, and (2) their antioxidant capacity.

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We have presented the largest series of solar urticaria published to date. The epidemiological, clinical, and photobiologic findings confirm previously reported data, although there was a particularly high rate of negative phototests in our series. Reactivity exclusively to visible or natural light was associated with a higher probability of resolution. No increasing trend was observed in the annual incidence.

Clothing is considered one of the most important tools for photoprotection against harmful solar ultraviolet radiation (UVR). The standard for sun-protective clothing is based on erythema despite other biological effects of UVR on the skin. We analyzed the potential protection against UVR in fabrics destined for summer clothing based on several action spectra. We examined 50 garments classified by type of fabric composition, structure of the fiber yarn and color. The ultraviolet protection factor was calculated based on fabric ultraviolet transmittance corrected for erythema according to the EU standard E-13758 as well as the UVA transmittance of fabrics. UVR protection was also analyzed in base of different action spectra as for previtamin D3, nonmelanoma skin cancer, photoimmunosuppression and photoaging. Most knitted fabrics used for sports T-shirts offered excellent ratings for ultraviolet protection while normal shirts showed very low ratings, particularly against photoaging. The cover is the most influential variable in fabric photoprotection, having an exponential relationship with the UPF. The relation between cover and UVA protection was linearly negative. Information about ultraviolet protection in textiles used for summer clothing should be included in labeling as some types of fabrics, especially those used for shirts, offer very low UVR protection.

Cutaneous detection of Leishmania is frequent in HIV-infected individuals with visceral leishmaniasis. Sometimes Leishmania is associated with changes attributable to other dermatological processes, and its presence does not imply a causative role. A clear relationship between the systemic process and the therapeutic response is necessary to demonstrate an ethiologic role.

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The rising incidence of skin cancers attributable to excessive sun exposure has become a major health concern worldwide. While numerous studies have analyzed the sun protective effect of sunscreens, clothing and antioxidants, none to date have measured the photoprotective effect of hair, despite clinical evidence that individuals with balding or thinning hair are at greater risk of skin lesions that can progress to cancer, hence the recommendation to use hats or umbrellas. We analyzed the level of protection offered by hair according to hair density, thickness and color using the spectral transmittance and corrected for relative erythema effectiveness. Our results show that hair provides a barrier against both UVB and UVA radiation which is significantly increased with respect to the hair density, thickness and the presence of melanins. This is the first study to quantify sun protection factor offered by hair, namely hair ultraviolet protection factor (HUPF). We believe that hair should be recognized as an important natural sun barrier in the prevention of UV-induced skin cancers.

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