The ion channel activator CyPPA inhibits melanogenesis via the GSK3ß/ß-catenin pathway.

Research into materials that inhibit melanogenesis in skin has gained interest. Screening for such compounds in B16F10 cells revealed that cyclohexyl-[2-(3,5-dimethyl-pyrazol-1-yl)-6-methyl-pyrimidin-4-yl]-amine (CyPPA), a positive modulator of small-conductance Ca2+-activated K+ channels, is a strong inhibitor of melanogenesis. We investigated the anti-melanogenic activity of CyPPA and the molecular mechanism by which CyPPA reduced melanin production in normal human melanocytes (NHM). CyPPA treatment resulted in a significant concentration-dependent reduction in melanin content without significant cytotoxicity; treatment likewise resulted in a significant time-dependent reduction in tyrosinase (TYR) activity. Treatment with CyPPA also decreased transcription of melanogenesis-related genes, including the gene encoding microphthalmia-associated transcription factor (MITF). In addition, visual evaluation of the MelanoDerm™ human skin model revealed significantly lower melanin content in the CyPPA-treated condition than in the untreated control. CyPPA was determined to modulate glycogen synthase kinase-3ß (GSK3ß) activity, thereby leading to a decrease in ß-catenin/MITF expression. Thus, CyPPA acts as a melanogenesis inhibitor by modulating the GSK3ß/ß-catenin/MITF pathway.

Histological and molecular analysis of the long-pulse 1,064-nm Nd:YAG laser irradiation on the ultraviolet-damaged skin of hairless mice: In association with pulse duration change.

BACKGROUND: Nonablative lasers have been widely used to improve photodamaged skin, although the mechanism underlying dermal collagen remodeling remains unclear. OBJECTIVE: To investigate the effects and the molecular mechanisms of long-pulse neodymium-doped yttrium aluminum garnet (Nd:YAG) laser irradiation on dermal collagen remodeling in association with different pulse durations. MATERIAL AND METHODS: Five hairless mice were pretreated with ultraviolet B irradiation for 8 weeks. The dorsal quadrant of each mouse was then irradiated twice at 1-week intervals at a pulse duration of 1 ms, 12 ms, or 50 ms, and a constant fluence of 20 J/cm(2). The levels of dermal collagen, mRNAs of procollagens, matrix metalloproteinases (MMPs), tissue inhibitor of metalloproteinases (TIMPs), and various growth factors were analyzed after 4 weeks. RESULTS: Long-pulse Nd:YAG treatment increased the dermal collagen level. A substantial increase in the level of procollagens, MMPs, TIMPs, and various growth factors was also observed irrespective of pulse duration, with a trend toward maximal increase at a pulse duration of 12 ms. CONCLUSION: Long-pulse 1,064-nm Nd:YAG laser irradiation promotes wound-healing process, which is characterized by the induction of growth factor expression and subsequent increase in MMPs and TIMPs, followed by matrix remodeling as confirmed by new procollagen production.

Red ginseng extract promotes the hair growth in cultured human hair follicles.

Ginseng has been shown to promote hair growth in several recent studies. However, its effects on human hair follicles and its mechanisms of action have not been sufficiently elucidated. This study aimed to investigate the hair growth-promoting effects of red ginseng extract (RGE) and its ginsenosides. The proliferative activities of cultured human hair follicles treated with RGE and ginsenoside-Rb1 were assessed using Ki-67 immunostaining. Their effects on isolated human dermal papilla cells (hDPCs) were evaluated using cytotoxicity assays, immunoblot analysis of signaling proteins, and the determination of associated growth factors. We examined the ability of RGE and ginsenosides to protect hair matrix keratinocyte proliferation against dihydrotestosterone (DHT)-induced suppression and their effects on the expression of androgen receptor. The in vivo hair growth-promoting effect of RGE was also investigated in C57BL/6 mice. Both RGE and ginsenoside-Rb1 enhanced the proliferation of hair matrix keratinocytes. hDPCs treated with RGE or ginsenoside-Rb1 exhibited substantial cell proliferation and the associated phosphorylation of ERK and AKT. Moreover, RGE, ginsenoside-Rb1, and ginsenoside-Rg3 abrogated the DHT-induced suppression of hair matrix keratinocyte proliferation and the DHT-induced upregulation of the mRNA expression of androgen receptor in hDPCs. Murine experiments revealed that the subcutaneous injection of 3% RGE resulted in more rapid hair growth than the negative control. In conclusion, RGE and its ginsenosides may enhance hDPC proliferation, activate ERK and AKT signaling pathways in hDPCs, upregulate hair matrix keratinocyte proliferation, and inhibit the DHT-induced androgen receptor transcription. These results suggest that red ginseng may promote hair growth in humans.

Synthesis of water well-dispersed PEGylated iron oxide nanoparticles for MR/optical lymph node imaging.

We reported the synthesis of highly water-stable iron oxide nanoparticles by a simple one-pot reaction. Non-toxic polyethylene glycol MW 600 (PEG) acted as a solvent, capping agent and reducing agent in the synthesis of iron oxide nanoparticles. As a result of the synthesis, PEGylated small-size (4.2 ± 0.39 nm average diameter and 7.2 ± 1.9 nm hydrodynamic sizes measuring by DLS) iron oxide nanoparticles (USPIO) were obtained, which show great colloidal stability in water and tolerate high salt concentration (0.75 M sodium chloride) and a wide pH range of 4 to 12. Oxidation of PEG was observed during the synthesis of iron oxide nanoparticles, which makes USPIO easy to functionalize with other molecules. Functionalization of the USPIO surface with fluorescein isothiocyanate (FITC) was conducted for investigating the possibility for multimodal imaging. Also the cytotoxicity test and lymph node imaging were performed by using the FITC labelled USPIO (FITC@USPIO). According to these results, the stable water dispersed USPIO and FITC@USPIO are expected to apply for multimodal in vivo imaging.