Enhancement of skin barrier and hydration-related molecules by protopanaxatriol in human keratinocytes

Abstract

Background Protopanaxatriol (PPT) is a secondary intestinal metabolite of ginsenoside in ginseng. Although the effects of PPT have been reported in various diseases including cancer, diabetes and inflammatory diseases, the skin protective effects of PPT are poorly understood. Methods HaCaT cells were treated with PPT in a dose-dependent manner. mRNA and protein levels which related to skin barrier and hydration were detected compared with retinol. Luciferase assay was performed to explore the relative signaling pathway. Western blot was conducted to confirm these pathways and excavated further signals. Results PPT enhanced the expression of filaggrin (FLG), transglutaminase (TGM)-1, claudin, occludin and hyaluronic acid synthase (HAS) −1, −2 and −3. The mRNA expression levels of FLG, TGM-1, HAS-1 and HAS-2 were suppressed under NF-κB inhibition. PPT significantly augmented NF-κB-luc activity and upregulated Src/AKT/NF-κB signaling. In addition, PPT also increased phosphorylation of the mitogen-activated protein kinases (MAPKs) ERK, JNK and p38 and upstream MAPK activators (MEK and MKK). Furthermore, transcriptional activity of AP-1 and CREB, which are downstream signaling targets of MAPK, was enhanced by PPT. Conclusion PPT improves skin barrier function and hydration through Src/AKT/NF-κB and MAPK signaling. Therefore, PPT may be a valuable component for cosmetics or treating skin disorders.

Antimelanogenesis Effects of Theasinensin A

“…We further confirmed the antimelanogenic effect of TSA by regulating the cAMP/CREB signaling pathway in B16F10 melanoma cells. To measure CREB transcriptional activity, we conducted a CREB-mediated luciferase assay in B16F10 cells, as reported previously [ 32 ]. TSA at 25 µM significantly decreased CREB-mediated luciferase activity in B16F10 cells ( Figure 4 d).…”

“…B16F10 cells (1 × 10 5 cells/well) were seeded for 24 h into a 12-well plate prior to transfection with plasmids (0.8 µg/mL per well), encoding a luciferase gene under a CREB promoter and β-galacosidase as a control by the lipofectamine method, as previously reported [ 32 ]. After 24 h of stabilization, the transfected cells were treated with TSA (12.5–25 µM) or arbutin (1 mM) concomitantly with α-MSH (100 nM) for the next 24 h. Luciferase activity was assessed using the Luciferase Assay System (Promega, Madison, WI, USA), as previously reported [ 64 , 65 ].…”

Wound Healing Effect of Gintonin Involves Lysophosphatidic Acid Receptor/Vascular Endothelial Growth Factor Signaling Pathway in Keratinocytes

“…Rapid wound healing and skin regeneration require the use of pharmaceuticals after a skin injury. Many herbal extracts and compounds have been demonstrated to have wound-healing effects on injured skin [17][18][19]27,[32][33][34]. Ginseng extract can also promote skin wound healing [17][18][19].…”

“…Gintonin can also promote hair growth and proliferation of hair follicle cells in mice [ 16 ]. Ginseng extracts were also reported to promote skin wound healing [ 17 , 18 , 19 ]. We have shown that a gintonin-enriched fraction (GEF) of ginseng can enhance hyaluronic acid and collagen release from human skin fibroblasts via LPA receptor activation [ 20 ].…”

“…Therefore, controlling the biological events of these cell types may be important for promoting wound healing of the skin. Many extracts derived from herbal plants are known to have skin wound healing activity [17][18][19]27,[32][33][34]. However, the skin wound healing effect and mechanism of action of gintonin in keratinocytes have not been elucidated yet.…”