Ultraviolet Filters: Dissecting Current Facts and Myths

Skin cancer is a global and increasingly prevalent issue, causing significant individual and economic damage. UV filters in sunscreens play a major role in mitigating the risks that solar ultraviolet ra-diation poses to the human organism. While empirically effective, multiple adverse effects of these compounds are discussed in the media and in scientific research. UV filters are blamed for the dis-ruption of endocrine processes and vitamin D synthesis, damaging effects on the environment, induction of acne and neurotoxic and carcinogenic effects. Some of these allegations are based on scientific facts while others are simply arbitrary. This is especially dangerous considering the risks of exposing unprotected skin to the sun. In summary, UV filters approved by the respective governing bodies are safe for human use and their proven skin cancer-preventing properties make them in-dispensable for sensible sun protection habits. Nonetheless, compounds like octocrylene and ben-zophenone-3 that are linked to the harming of marine ecosystems could be omitted from skin care regimens in favor of the myriad of non-toxic UV filters.

Cholesterol uptake in the intestine is regulated by the LASP1-AKT-NPC1L1 signaling pathway

Cholesterol is essential for the stability and architecture of the plasma membrane and a precursor of bile acids and steroid hormones in mammals. Excess dietary cholesterol uptake leads to hypercholesterolaemia, atherosclerosis and plays a role in cancer development. The role of actin-binding scaffolding protein LIM and SH3 protein 1 (LASP1) in cholesterol trafficking has not been investigated previously. Cholesterol levels, its uptake and excretion were studied in mice deficient for low density lipoprotein receptor and Lasp1 (Ldlr-/-Lasp1-/- mice) upon feeding a high fat diet, and in LASP1-knockdown, differentiated human intestinal epithelial Caco-2 cells. Compared to diet-fed Ldlr-/- control mice, Ldlr-/-Lasp1-/- mice displayed a reduction in serum cholesterol levels. Mechanistically, we identified a new role of LASP1 in controlling the translocation of the intestinal cholesterol transporter Niemann-Pick C1-like 1 (NPC1L1) to the apical cell surface, which was limited in LASP1-knockdwon human CaCo-2 enterocytes and in the intestine of Ldlr-/- Lasp1-/- compared to Ldlr-/-mice, linked to LASP1-pAKT signaling but not CDC42 activation. In line, a reduction in cholesterol reabsorption was noted in LASP1-knockdown CaCo-2 cells in vitro, and an enhanced cholesterol excretion via the feces was observed in Ldlr-/- Lasp1-/- mice. These data uncover a novel function of Lasp1 in cholesterol trafficking, promoting cholesterol reabsorption in the intestine. Targeting LASP1 locally could thus represent a novel targeting strategy to ameliorate hypercholesterolemia and associated diseases.

Experimental scoliosis in the course of unilateral surface electrostimulation of the paravertebral muscles in rabbits: effects according to stimulation period

Scoliosis among children and adolescents is a persistent problem. Worldwide, it afflicts between 0.3 to 15.3% of the population. One of the treatment methods of this disorder is to administer lateral electrical surface stimulation (LESS) for 9 h/day; unfortunately, however, this results in side-effects. Improvements are therefore sought. The main aim of the study was to investigate the effects of the duration of LESS on scoliosis progression and to evaluate, qualitatively, any associated macroscopic effect on other internal organs. The length of the LESS period was based on the results of previous clinical trials in children. The experiment was performed on 13 developing rabbits (aged 3.5 months), divided into three groups: group 1, rabbits subsequently treated for 9 h/day (n=5); group 2, animals treated for 2 h/day (n=5); group 3, control rabbits without electrostimulation (n=3). Stimulation was carried out using an electric stimulator SCOL-2 according to the method modified by Kowalski. The animals were killed after 3 months and examined macroscopically, and their adrenal glands were dissected and weighed. The X-rays of the spine of the animals were taken to analyse spinal deformity. Macroscopic lesions in rabbits from groups 2 and 3 (control) were mostly absent. While there was considerable deviation in group 1, all the stress features were apparent. The enlargement of the adrenal glands observed in group 2 was significantly less marked than in group 1. The degree of scoliotic deformity (according to the Cobb method) ranged from 21 degrees to 410 degrees (mean, 31.2 degrees) and from 23 degrees to 330 degrees (mean, 30 degrees) in groups 1 and 2, respectively. LESS resulted in spinal deformity to a similar degree in the rabbits treated for either 9 or 2 h/day over a 3-month period. Short LESS therapy (2 h/day) significantly reduced detrimental effects associated with the treatment on internal organs of laboratory animals.