18-ß-Glycyrrhetinic Acid Promotes Hair Growth by Stimulating the Proliferation of Dermal Papilla Cells and Outer Root Sheath Cells, and Extends the Anagen Phase by Inhibiting 5α-Reductase.

18-ß-Glycyrrhetinic acid, a major component of licorice, stimulated the proliferation of both dermal papilla cells and outer root sheath cells isolated from human hair follicles. Thus, suggesting that this compound promotes hair growth. Furthermore, this compound inhibited the activity of testosterone 5α-reductase, an enzyme responsible for converting androgen to dihydroandrogen, with an IC50 of 137.1 µM. 18-ß-Glycyrrhetinic acid also suppressed the expression of transforming growth factor-ß1 (TGF-ß1), which shifts the hair cycle from the anagen phase to the telogen phase. It suggested that this compound may prolong the anagen phase. Based on these findings, this compound could be a potentially effective treatment for androgenetic alopecia.

Ginsenosides in Panax ginseng Extract Promote Anagen Transition by Suppressing BMP4 Expression and Promote Human Hair Growth by Stimulating Follicle-Cell Proliferation.

Studies showing that Panax ginseng promotes hair growth have largely been conducted using mice; there are few reports on how P. ginseng affects human hair growth. In particular, little is known about its effect on the telogen to anagen transition. To determine the effect of P. ginseng on human hair growth and the transition from the telogen to the anagen phase. The effects of P. ginseng extract (PGE) and the three major ginsenoside components, Rb1, Rg1, and Re, on the proliferation of human dermal papilla cells (DPCs) and human outer root sheath cells (ORSCs) were investigated. The effects of these compounds on the cell expression of bone morphogenetic protein 4 (BMP4), fibroblast growth factor 18 (FGF18) and Noggin were assessed by real-time PCR. The effect of PGE on hair-shaft elongation was determined in a human hair follicle organ-culture system. PGE and the three ginsenosides stimulated the proliferation of DPCs and ORSCs and suppressed BMP4 expression in DPCs but did not affect FGF18 expression in ORSCs and Noggin expression in DPCs. PGE stimulated hair-shaft growth. PGE and the ginsenosides Rb1, Rg1, and Re stimulate the transition from the telogen phase to anagen phase of the hair cycle by suppressing BMP4 expression in DPCs. These compounds might be useful for promoting the growth of human hair.

Star fruit extract and C-glycosylated flavonoid components have potential to prevent air pollutant-induced skin inflammation and premature aging.

Air pollution adversely affects skin, leading to skin inflammation and premature skin aging. Plant derived antioxidant compounds have been considered to be promising in discovery of effective agents for the protection of skin from the damage by air pollutants. Our previous studies demonstrated that Averrhoa carambola fruit (known as star fruit) is rich in flavonoid C-glycosides with unique structures and potent antioxidant activity. Thus, the star fruit extract (SFE) and main flavonoid C-glycoside components, carambolasides I, J, and P (1-3), carambolaflavone B (4), and isovitexin 2″-O-α-L-rhamnoside (5), were investigated for the activity against air pollutant stress in human epidermis. As a result, SFE and compounds 1-5 exhibited significant inhibitory activity against protein carbonylation in oxidative-stressed stratum corneum with the best activity being shown by compound 3. SFE and compounds 2-5 were also active against engine exhaust-induced protein carbonylation in stratum corneum. When further evaluated, SFE and compound 3 significantly inhibited gene expression of the key inflammation mediators IL-1α and COX-2 in PM-stressed keratinocytes. The results indicated that SFE and the flavonoid C-glycosides are potentially effective against air pollutant-induced skin inflammation and premature aging.

Inhibitory effect of strawberry geranium (Saxifraga stolonifera) on Toll-like receptor 2-mediated inflammatory response in human skin keratinocytes.

ETHNOPHARMACOLOGICAL RELEVANCE: Strawberry geranium (Saxifraga stolonifera [L.] Meeb) has traditionally been used as a drug to treat skin disorders in Japan. However, little is known about its physiological effects on skin keratinocytes. AIM OF THE STUDY: We investigated the anti-inflammatory effects of a strawberry geranium extract (SGE) on human skin keratinocytes. MATERIALS AND METHODS: The human keratinocyte cell line, HaCaT, was treated with SGE, and then stimulated with tumor necrosis factor (TNF)-α. The expression of 207 genes related to the innate immune system was analyzed using DNA microarrays. The effect of SGE on the target proteins in primary human epidermal keratinocytes was confirmed by quantitative reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay. The mechanisms of action and active components involved in the suppressive effect of SGE were evaluated by fractionation and a transcription assay. RESULTS: The microarray analysis revealed that SGE primarily suppressed Toll-like receptor (TLR)2 expression through procyanidin B2 3,3'-di-O-gallate, without TLR2 downregulation, in TNF-α-stimulated HaCaT cells. SGE suppressed TLR2 expression and interleukin (IL)-8 production induced by TLR2 ligands in primary human epidermal keratinocytes and HaCaT cells. Multiple components downregulating TLR2 expression suppressed the Sp1 activity. CONCLUSIONS: We identified a novel physiological function of SGE, which suppresses TLR2 expression and TLR2-mediated inflammation in human skin keratinocytes. This study provides significant insights into the anti-inflammatory effect of SGE in human skin.