A systematic exploration of ginsenoside Rg5 reveals anti-inflammatory functions in airway mucosa cells.

Background: Hyperactivated airway mucosa cells overproduce mucin and cause severe breathing complications. Here, we aimed to identify the effects of saponins derived from Panax ginseng on inflammation and mucin overproduction. Methods: NCI-H292 cells were pre-incubated with 16 saponins derived from P. ginseng, and mucin overproduction was induced by treatment with phorbol 12-myristate 13-acetate (PMA). Mucin protein MUC5AC was quantified by enzyme-linked immunosorbent assay, and mRNA levels were analyzed using quantitative polymerase chain reaction (qPCR). Moreover, we performed a transcriptome analysis of PMA-treated NCI-H292 cells in the absence or presence of Rg5, and differential gene expression was confirmed using qPCR. Phosphorylation levels of signaling molecules, and the abundance of lipid droplets, were measured by western blotting, flow cytometry, and confocal microscopy. Results: Ginsenoside Rg5 effectively reduced MUC5AC secretion and decreased MUC5AC mRNA levels. A systematic functional network analysis revealed that Rg5 upregulated cholesterol and glycerolipid metabolism, resulting in the production of lipid droplets to clear reactive oxygen species (ROS), and modulated the mitogen-activated protein kinase and nuclear factor (NF)-κB signaling pathways to regulate inflammatory responses. Rg5 induced the accumulation of lipid droplets and decreased cellular ROS levels, and N-acetyl-l-cysteine, a ROS inhibitor, reduced MUC5AC secretion via Rg5. Furthermore, Rg5 hampered the phosphorylation of extracellular signal-regulated kinase and p38 proteins, affecting the NF-κB signaling pathway and pro-inflammatory responses. Conclusion: Rg5 alleviated inflammatory responses by reducing mucin secretion and promoting lipid droplet-mediated ROS clearance. Therefore, Rg5 may have potential as a therapeutic agent to alleviate respiratory disorders caused by hyperactivation of mucosa cells.

A systematic exploration reveals the potential of spermidine for hypopigmentation treatment through the stabilization of melanogenesis-associated proteins.

Spermidine (SPD), a polyamine naturally present in living organisms, is known to prolong the lifespan of animals. In this study, the role of SPD in melanogenesis was investigated, showing potential as a pigmenting agent. SPD treatment increased melanin production in melanocytes in a dose dependent manner. Computational analysis with RNA-sequencing data revealed the alteration of protein degradation by SPD treatment without changes in the expressions of melanogenesis-related genes. Indeed, SPD treatment significantly increased the stabilities of tyrosinase-related protein (TRP)-1 and -2 while inhibiting ubiquitination, which was confirmed by treatment of proteasome inhibitor MG132. Inhibition of protein synthesis by cycloheximide (CHX) showed that SPD treatment increased the resistance of TRP-1 and TRP-2 to protein degradation. To identify the proteins involved in SPD transportation in melanocytes, the expression of several solute carrier (SLC) membrane transporters was assessed and, among 27 transporter genes, SLC3A2, SLC7A1, SLC18B1, and SLC22A18 were highly expressed, implying they are putative SPD transporters in melanocytes. Furthermore, SLC7A1 and SLC22A18 were downregulated by SPD treatment, indicating their active involvement in polyamine homeostasis. Finally, we applied SPD to a human skin equivalent and observed elevated melanin production. Our results identify SPD as a potential natural product to alleviate hypopigmentation.

Human milk oligosaccharide 2'-fucosyllactose promotes melanin degradation via the autophagic AMPK-ULK1 signaling axis.

There is still an unmet need for development of safer antimelanogenic or melanin-degrading agents for skin hyperpigmentation, induced by intrinsic or extrinsic factors including aging or ultraviolet irradiation. Owing to the relatively low cytotoxicity compared with other chemical materials, several studies have explored the role of 2'-fucosyllactose (2'-FL), the most dominant component of human milk oligosaccharides. Here, we showed that 2'-FL reduced melanin levels in both melanocytic cells and a human skin equivalent three-dimensional in vitro model. Regarding the cellular and molecular mechanism, 2'-FL induced LC3I conversion into LC3II, an autophagy activation marker, followed by the formation of LC3II+/PMEL+ autophagosomes. Comparative transcriptome analysis provided a comprehensive understanding for the up- and downstream cellular processes and signaling pathways of the AMPK-ULK1 signaling axis triggered by 2'-FL treatment. Moreover, 2'-FL activated the phosphorylation of AMPK at Thr172 and of ULK1 at Ser555, which were readily reversed in the presence of dorsomorphin, a specific AMPK inhibitor, with consequent reduction of the 2'-FL-mediated hypopigmentation. Taken together, these findings demonstrate that 2'-FL promotes melanin degradation by inducing autophagy through the AMPK-ULK1 axis. Hence, 2'-FL may represent a new natural melanin-degrading agent for hyperpigmentation.

Nicotinamide mononucleotide reduces melanin production in aged melanocytes by inhibiting cAMP/Wnt signaling.

BACKGROUND: Nicotinamide mononucleotide (NMN) is a representative anti-aging drug that, after long-term administration in mice, causes an increase in energy and lipid metabolism, improves eye function, immune response, and increases insulin sensitivity. However, the effects of NMN on skin pigmentation are still unknown. OBJECTIVE: In this study, we aimed to demonstrate the effects of NMN on melanogenesis. METHODS: NMN was applied to both young and aged melanocytes, and melanin production, protein expression, and mRNA levels were analyzed. A reconstituted human skin model was used to validate the effect of NMN on melanogenesis in vivo. RESULTS: NMN treatment showed no apparent effects on young melanocytes, however, in aged melanocytes, a marked reduction in melanin production was observed. NMN treatment also efficiently reduced melanin production in a reconstituted human skin with aged melanocytes. Genome-wide analysis showed the downregulation of melanogenesis-related cyclic adenosine monophosphate (cAMP)/Wnt signaling in aged melanocytes. Moreover, NMN treatment downregulated forskolin-induced expression of melanogenesis-related proteins, tyrosinase (TYR), tyrosinase-related protein (TRP)- 1, and TRP-2. Nicotinamide adenine dinucleotide (NAD+), an NMN product within the cells, also reduced cAMP/Wnt signaling in aged melanocytes. SLC12A6 was the most highly expressed gene among the SLC12A family members in melanocytes and was significantly influenced by NMN or NAD+ treatment, indicating that SLC12A6 protein is an NMN transporter in melanocytes. CONCLUSION: NMN reduces melanogenesis in aged melanocytes by downregulating the signaling of melanogenesis-associated receptors. Therefore, NMN is a human-friendly anti-melanogenic agent with the potential to aid in aging-related hyperpigmentation therapy.

Applications of Mesenchymal Stem Cells in Skin Regeneration and Rejuvenation.

Mesenchymal stem cells (MSCs) are multipotent stem cells derived from adult stem cells. Primary MSCs can be obtained from diverse sources, including bone marrow, adipose tissue, and umbilical cord blood. Recently, MSCs have been recognized as therapeutic agents for skin regeneration and rejuvenation. The skin can be damaged by wounds, caused by cutting or breaking of the tissue, and burns. Moreover, skin aging is a process that occurs naturally but can be worsened by environmental pollution, exposure to ultraviolet radiation, alcohol consumption, tobacco use, and undernourishment. MSCs have healing capacities that can be applied in damaged and aged skin. In skin regeneration, MSCs increase cell proliferation and neovascularization, and decrease inflammation in skin injury lesions. In skin rejuvenation, MSCs lead to production of collagen and elastic fibers, inhibition of metalloproteinase activation, and promote protection from ultraviolet radiation-induced senescence. In this review, we focus on how MSCs and MSC-derived molecules improve diseased and aged skin. Additionally, we emphasize that induced pluripotent stem cell (iPSC)-derived MSCs are potentially advanced MSCs, which are suitable for cell therapy.

α-Pinene Enhances the Anticancer Activity of Natural Killer Cells via ERK/AKT Pathway.

Natural killer (NK) cells are lymphocytes that can directly destroy cancer cells. When NK cells are activated, CD56 and CD107a markers are able to recognize cancer cells and release perforin and granzyme B proteins that induce apoptosis in the targeted cells. In this study, we focused on the role of phytoncides in activating NK cells and promoting anticancer effects. We tested the effects of several phytoncide compounds on NK-92mi cells and demonstrated that α-pinene treatment exhibited higher anticancer effects, as observed by the increased levels of perforin, granzyme B, CD56 and CD107a. Furthermore, α-pinene treatment in NK-92mi cells increased NK cell cytotoxicity in two different cell lines, and immunoblot assays revealed that the ERK/AKT pathway is involved in NK cell cytotoxicity in response to phytoncides. Furthermore, CT-26 colon cancer cells were allografted subcutaneously into BALB/c mice, and α-pinene treatment then inhibited allografted tumor growth. Our findings demonstrate that α-pinene activates NK cells and increases NK cell cytotoxicity, suggesting it is a potential compound for cancer immunotherapy.

Component analysis of four-part extracts from Chamaecyparis obtusa Endl. by supercritical fluid extraction and anti-inflammatory effect on RAW 264.7cells.

The main purpose of this study was to suggest a solution for inflammation caused by urban daily life based on supercritical extraction of Chamaecyparis obtusa Endl. (C. obtusa). The leaves, cone, wood, and bark of C. obtusa were separately extracted with supercritical extraction. Alpha-pinene, anti-inflammatory active compound of C. obtusa, was analyzed by electrospray ionization-mass spectrometry, gas chromatography, and gas chromatography mass spectrometry from each part of extracts. As a result of the reduction rate of nitric oxide in RAW 264.7 cells, the wood extract exhibited the highest reduction rate was about 45% among extracts from four part of C. obtusa. The wood extract from C. obtusa can be developed as a good anti-inflammatory natural raw material for natural product industry.