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Collagen hydrolysate administration affects epidermal barrier function and dermal skin elasticity.

Exposure to ultraviolet-B (UV-B) irradiation causes skin barrier defects. Based on earlier findings that milk phospholipids containing high amounts of sphingomyelin (SM) improved the water content of the stratum corneum (SC) in normal mice, here we investigated the effects of dietary milk SM on skin barrier defects induced by a single dose of UV-B irradiation in hairless mice. Nine week old hairless mice were orally administrated SM (146 mg/kg BW/day) for a total of ten days. After seven days of SM administration, the dorsal skin was exposed to a single dose of UV-B (20 mJ/cm2). Administration of SM significantly suppressed an increase in transepidermal water loss and a decrease in SC water content induced by UV-B irradiation. SM supplementation significantly maintained covalently-bound ω-hydroxy ceramide levels and down-regulated mRNA levels of acute inflammation-associated genes, including thymic stromal lymphopoietin, interleukin-1 beta, and interleukin-6. Furthermore, significantly higher levels of loricrin and transglutaminase-3 mRNA were observed in the SM group. Our study shows for the first time that dietary SM modulates epidermal structures, and can help prevent disruption of skin barrier function after UV-B irradiation.

Supplementation with sphingomyelin has been reported to have beneficial effects on disease prevention and health maintenance. However, compared with glycerolipids, intact sphingomyelin and ceramides are poorly absorbed. Therefore, if the bioavailability of dietary sphingomyelin is increased, then the dose administered can be reduced. This study was designed to identify molecular species of ceramide in rat lymph after the ingestion of milk sphingomyelin, and to compare the effect of purified sphingomyelin with milk phospholipids concentrate (MPL, 185 mg sphingomyelin/g) on lymphatic absorption of milk sphingomyelin. Lymph was collected hourly for 6 h from lymph-cannulated rats (n = 8/group) after the administration of a control emulsion (triolein, bovine serum albumin, and sodium taurocholate), a sphingomyelin emulsion (control + purified sphingomyelin), or a MPL emulsion (control + MPL). Molecular species of ceramide in lymph were analyzed using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Molecular species of ceramide, containing not only d18:1, but also d17:1 and d16:1 sphingosine with 16:0, 22:0, 23:0, and 24:0 fatty acids (specific to milk sphingomyelin), were increased in rat lymph after the administration of milk sphingomyelin. Their molecular species were similar to those of dietary milk sphingomyelin. Recovery of ceramide moieties from dietary sphingomyelin was 1.28- to 1.80-fold significantly higher in the MPL group than in the sphingomyelin group. Our results demonstrated that dietary sphingomyelin from milk was transported to lymph as molecular species of ceramide hydrolyzed from milk sphingomyelin and co-ingestion of sphingomyelin with glycerophospholipids enhanced the bioavailability of dietary sphingomyelin.

The striatonigral and olivopontocerebellar systems are known to be vulnerable in multiple system atrophy (MSA), showing neuronal loss, astrogliosis, and alpha-synuclein-immunoreactive inclusions. MSA patients who displayed abundant neuronal cytoplasmic inclusions (NCIs) in the regions other than the striatonigral or olivopontocerebellar system have occasionally been diagnosed with variants of MSA. In this study, we report clinical and pathologic findings of MSA patients characterized by prominent pathologic involvement of the hippocampus. We assessed 146 consecutively autopsied MSA patients. Semiquantitative analysis of anti-alpha-synuclein immunohistochemistry revealed that 12 of 146 patients (8.2%) had severe NCIs in two or more of the following areas: the hippocampal granule cells, cornu ammonis areas, parahippocampal gyrus, and amygdala. In contrast, the remaining 134 patients did not show