Disorders of pigmentation: unapproved treatments

Hirseins inhibit melanogenesis by regulating the gene expressions of Mitf and melanogenesis enzymes

Previously, we reported that Thymelaea hirsuta extract has antimelanogenesis effect on B16 murine melanoma cells. The extract was subjected to fractionation, and hirsein A (HA) and hirsein B (HB) were discovered and tested for their ability to regulate melanogenesis in B16 cells. Western blot (WB) analysis was carried out to determine the expression of tyrosinase. Moreover, to elucidate the possible mechanism behind melanogenesis regulation, real-time PCR using primers for Mitf, Tyr, Trp1 and Dct genes, and protein kinase C (PKC) activity assay were carried out. Results clearly show that 0.1 mum HA and HB significantly reduced the melanin content. This reduction in melanin content was accompanied by reduced tyrosinase expression as detected by WB analysis. There was also a significant decrease in the expression level of Mitf gene in HA- and HB-treated cells. HA down-regulated the expressions of Tyr, Trp1 and Dct, whereas HB down-regulated only those of Trp1 and Dct. Interestingly, HB-treated cells had lower kinase activity than HA-treated cells indicating a possible difference in the activities of the compounds but with the same mechanism of melanogenesis regulation. We report for the first time that HA and HB can down-regulate melanogenesis by down-regulating Mitf gene expression, leading to reduced expressions of Tyr, Trp1 and Dct. The hirseins were also able to reduce the kinase activity, suggesting the possible involvement of PKC in the overall ability of the hirseins to down-regulate melanogenesis.

Documento de consenso sobre fototerapia: terapias PUVA y UVB de banda estrecha

It is essential to develop a consensus document on phototherapy in order to adapt this procedure to the specific characteristics, needs and reality of our milieu. Using a review of existing literature on the subject and the experience of its own members as a reference, the Spanish Photobiology Group (GEF) of the Spanish Academy of Dermatology and Venereology (AEDV) has developed some therapeutic guidelines for the most widely used modes of phototherapy: PUVA therapy and narrow-band UVB (NBUVB) therapy. These guidelines deal with generalities about the equipment, calibration and regulation in phototherapy booths, and the concept and indications for these forms of treatment are reviewed. Recommendations are also proposed regarding patient selection, therapeutic procedures, associated pharmacological agents of interest and the prevention and management of adverse effects. The consensus document is designed as a flexible and practical instrument intended for use in daily clinical practice, aimed at optimizing the possibilities of phototherapy while reducing risks for patients and therapists.