Current Data on Effects of Long-Term Missions on the International Space Station on Skin Physiological Parameters.

BACKGROUND: Skin reaction to spaceflight has not really been studied yet, although the skin has a very important barrier function to protect the body and can contribute to a more general understanding of physiology. It is proposed here to make a more thorough investigation of the skin during long-term spaceflight, using noninvasive techniques. AIMS: The aim of the present Skin-B study is to investigate the kinetics and range of possible skin modifications during long-duration spaceflights and their recovery. METHODS: In order to investigate the effect on skin physiological parameters during spaceflight, measurements were carried out on 6 astronauts with respect to skin hydration, transepidermal water loss/barrier function, and surface evaluation of the living skin in orbit. Additional measured parameters on the ground were skin elasticity, skin density and thickness, as well as microcirculation. RESULTS: Data from the Skin-B subjects (n = 6) contradict the results obtained in the previous pilot study SkinCare (n = 1 subject). In the present study, no deterioration of the skin was found but rather an improvement in skin hydration and skin barrier function, and no changes or improvement in the appearance of the skin surface. Furthermore, the skin density and skin thickness as well as skin elasticity values were unchanged from pre-flight values. CONCLUSION: In conclusion, we found that spaceflight under present conditions has no negative impact on skin physiological parameters.

Effect of the multifunctional cosmetic ingredient sphinganine on hair loss in males and females with diffuse hair reduction.

Sphingolipids are well known to promote keratinocyte differentiation and to induce ceramide production. In addition, they show anti-inflammatory and antimicrobial activities. Thus, the aim of this study is to investigate the potential effect of sphinganine on prolonging the hair anagen rate and improving the overall hair quality and scalp health. The inhibitory potential of sphinganine toward 5-α-reductase was studied using an in vitro assay. The stimulation of the antimicrobial peptide HBD2 by sphinganine was measured by real-time polymerase chain reaction and immunostaining. Sphinganine bioavailability was studied ex vivo using a pig skin model. A placebo-controlled, double-blind study was designed to evaluate the efficacy of sphinganine on hair loss and hair/scalp quality in vivo. In vitro results showed that sphinganine is a potent inhibitor of 5-α-reductase type I that prevents the conversion of testosterone to dihydrotestosterone, a key factor of androgenetic male baldness. In vivo results demonstrated efficacy in reducing non-illness-related hair loss among males. In terms of expert rating, all hair quality and scalp parameters improved after application of sphinganine. Improved scalp health might be linked to the observed increase of the antimicrobial peptide HBD2. Thus, sphinganine is well suited as a topical alternative for the improvement of scalp health and hair quality and anti-hair loss application.