RESUMEN
Chronic exposure of the skin to sunlight causes damage to the underlying connective tissue with a loss of elasticity and firmness. Silicon (Si) was suggested to have an important function in the formation and maintenance of connective tissue. Choline-stabilized orthosilicic acid ("ch-OSA") is a bioavailable form of silicon which was found to increase the hydroxyproline concentration in the dermis of animals. The effect of ch-OSA on skin, nails and hair was investigated in a randomized, double blind, placebo-controlled study. Fifty women with photodamaged facial skin were administered orally during 20 weeks, 10 mg Si/day in the form of ch-OSA pellets (n=25) or a placebo (n=25). Noninvasive methods were used to evaluate skin microrelief (forearm), hydration (forearm) and mechanical anisotropy (forehead). Volunteers evaluated on a virtual analog scale (VAS, "none=0, severe=3") brittleness of hair and nails. The serum Si concentration was significantly higher after a 20-week supplementation in subjects with ch-OSA compared to the placebo group. Skin roughness parameters increased in the placebo group (Rt:+8%; Rm: +11%; Rz: +6%) but decreased in the ch-OSA group (Rt: -16%; Rm: -19%; Rz: -8%). The change in roughness from baseline was significantly different between ch-OSA and placebo groups for Rt and Rm. The difference in longitudinal and lateral shear propagation time increased after 20 weeks in the placebo group but decreased in the ch-OSA group suggesting improvement in isotropy of the skin. VAS scores for nail and hair brittleness were significantly lower after 20 weeks in the ch-OSA group compared to baseline scores. Oral intake of ch-OSA during the 20 weeks results in a significant positive effect on skin surface and skin mechanical properties, and on brittleness of hair and nails.
Asunto(s)
Colina , Cabello/efectos de los fármacos , Uñas/efectos de los fármacos , Ácido Silícico/administración & dosificación , Piel/efectos de los fármacos , Piel/efectos de la radiación , Rayos Ultravioleta/efectos adversos , Administración Oral , Adulto , Anciano , Fenómenos Biomecánicos , Método Doble Ciego , Cara , Femenino , Cabello/patología , Cabello/fisiopatología , Humanos , Hidroxiprolina/metabolismo , Persona de Mediana Edad , Uñas/patología , Uñas/fisiopatología , Ácido Silícico/farmacología , Ácido Silícico/uso terapéutico , Silicio/sangre , Piel/metabolismo , Piel/patología , Factores de TiempoRESUMEN
Peculiarities of allergens extraction from the intact and destructed pollen grains of Ambrosia artemisiifolia L. have been studied, and the effect of the content of extracting buffer on stability of the obtained allergen extracts has been investigated. It is established that mechanical destruction of pollen during extraction permits decreasing protein output, increasing specific activity of the extracts and accelerating the procedure of their production. Introduction of some protective additions to the composition of the extracting buffer permits essentially increasing stability of the extracts under long-term storage at 4 degrees C.