Effects of Oral Supplementation with Paprika Xanthophylls on Human Skin Moisture.

Carotenoids, classified into carotenes and xanthophylls, are natural lipophilic pigments that are widely distributed in plants. Red paprika is unique in its high levels of various xanthophylls. Dietary paprika xanthophylls have been shown to reduce UV-induced photo damage by the strong antioxidant activity in the skin. However, the precise effects of paprika xanthophylls on skin condition are still unknown. Here we show that skin moisture is enhanced by the intake of red paprika supplements including seven xanthophylls. We conducted a 4-week randomized, single-blind, parallel-group controlled trial to clarify the effects of dietary paprika xanthophylls on facial skin. The results showed that the moisture was significantly higher in the paprika intake group than in the control (21.0±8.9 vs 13.4±6.0 (A.U.)). There was no significant difference between the paprika and control groups in other parameters such as viscoelasticity, the number of wrinkles, and the amount of water evaporation. On the other hand, the number of brown stains in the paprika group increased significantly, to 190±26 from 173±30 (p < 0.05). In vitro experiments, quantitative real-time PCR showed that paprika extract led to increases in the gene expression of Aquaporin 3 (AQP3) and hyaluronic acid synthase 3 (HAS3) in cultured keratinocytes. Western blotting showed that the paprika extract enhanced AQP3 expression. Taken together, taking supplements containing paprika xanthophylls may provide beneficial effects of moisture on facial skin. The study provides new insights into understanding the role of paprika xanthophylls in the skin.

Effects of Glycogen on Ceramide Production in Cultured Human Keratinocytes via Acid Sphingomyelinase Activation.

Glycogen is a highly branched storage polysaccharide found mainly in the liver and the muscles. Glycogen is also present in the skin, but its functional role is poorly understood. Recently, it has been reported that glycogen plays an important role in intracellular signal transduction. In the epidermis of the skin, keratinocytes are the predominant cells that produce ceramide. Ceramides are lipids composed of sphingosine, and prevent water loss, as well as protecting the skin against environmental stressors. In this study, we investigated the effects of glycogen on ceramide production in cultured keratinocytes. Thin-layer chromatography revealed that incubation of keratinocytes with 2 % glycogen enhanced the cellular amount of ceramide NS (ceramide 2) by 3.4-fold compared to the control. We also found that glycogen regulated the mRNA expression levels of signaling molecules of the sphingomyelin-ceramide pathway by quantitative real-time PCR. The activity of sphingomyelinase was also significantly enhanced by 2.5-fold in cultures with 1 % glycogen compared to the control. Moreover, glycogen increased the ATP production by 1.5-fold compared to the control, while glucose did not affect the production. Western blotting showed that phosphorylation of Akt, a cellular signaling molecule, was inhibited in the presence of glycogen in cultured keratinocytes. This study shows that glycogen upregulates the ceramide production pathway from sphingomyelin in epidermal keratinocytes, and provides new insights into the role of glycogen in cellular signal transduction.

Qualitative and Quantitative Analyses of Glycogen in Human Milk.

Identification as well as a detailed analysis of glycogen in human milk has not been shown yet. The present study confirmed that glycogen is contained in human milk by qualitative and quantitative analyses. High-performance anion exchange chromatography (HPAEC) and high-performance size exclusion chromatography with a multiangle laser light scattering detector (HPSEC-MALLS) were used for qualitative analysis of glycogen in human milk. Quantitative analysis was carried out by using samples obtained from the individual milks. The result revealed that the concentration of human milk glycogen varied depending on the mother's condition-such as the period postpartum and inflammation. The amounts of glycogen in human milk collected at 0 and 1-2 months postpartum were higher than in milk collected at 3-14 months postpartum. In the milk from mothers with severe mastitis, the concentration of glycogen was about 40 times higher than that in normal milk.