Platycladus orientalis is a traditional oriental herbal medicinal plant that is widely used as a component of complex prescriptions for alopecia treatment in Eastern Asia. The effect of PO on hair growth and its underlying mechanism, however, have not been demonstrated or clarified. In this study, we investigated the hair-growth-promoting effect of PO in cultured human dermal papilla cells (hDPCs). Platycladus orientalis leaf extract (POLE) was found to stimulate the proliferation of hDPCs. POLE with higher quercitrin concentration, especially, showed a high level of cellular viability. In the context of cellular senescence, POLE decreased the expression of p16 (CDKN2A) and p21(CDKN1A), which resulted in enhanced proliferation. In addition, growth factor receptors, FGFR1 and VEGFR2/3, and non-receptor tyrosine kinases, ACK1 and HCK, were significantly activated. In addition, LEF1, a transcription factor of Wnt/β-catenin signaling, was enhanced, but DKK1, an inhibitor of Wnt/β-catenin signaling, was downregulated by POLE treatment in cultured hDPCs. As a consequence, the expression of growth factors such as bFGF, KGF, and VEGF were also increased by POLE. We further investigated the hair-growth-promoting effect of topically administered POLE over a 12-week period. Our data suggest that POLE could support terminal hair growth by stimulating proliferation of DPCs and that enhanced production of growth factors, especially KGF, occurred as a result of tyrosine kinase ACK1 activation.

Microcirculation in cutaneous tissue is essential to balance oxygen delivery and maintain the health of the skin. Senescence contributes to microcirculatory dysfunction through mechanisms involving chronic inflammation, structural remodeling of microvessels, and disturbances in hemodynamics. In this study we investigated the promoting effect of escin on blood flow through topical application. To elucidate the molecular mechanisms of escin, kinase phosphorylation changes in human umbilical vein endothelial cells (HUVECs) were examined. Escin stimulates the Wnt/β-Catenin and c-Jun N-terminal kinase (JNK) signaling pathway in cultured HUVECs. To clarify the target of escin in the Wnt/β-Catenin signaling pathway, gene expression in response to escin treatment was evaluated, and escin-mediated signaling activation was accompanied by glycogen synthase kinase-3 beta (Gsk3β), according to inhibitor studies performed with IWR1 (tankyrase inhibitor). In addition, the expression level of the Gsk3β were down-regulated by escin treatment in cultured HUEVCs. Escin also enhanced vascular remodeling, and, when applied topically, led to a sustained increase in cutaneous blood flow. Escin-mediated Wnt signaling activation could enhance blood vessel networks via Gsk3β down-regulation. In conclusion, our data demonstrate that escin promotes angiogenic behavior and enhances adenosine-induced perfusion in humans, thereby supporting its potential role in modulating cutaneous microcirculation.

The fungi and bacteria on the human scalp play important roles in both health and disease. Scalp biofilms have pathogenic effects on cutaneous tissues, such as seborrheic dermatitis. However, investigations into scalp biofilms and their physiological effects on scalp skin are limited. In this study, we suggest an evaluation method through which the scalp is stained a reddish color using erythrosine to visualize scalp biofilms, which strongly depends on the presence of bacteria and fungi. We found that the physiological properties of the scalp significantly differed between high and low levels of stained red areas (sRAs) on the scalp. The sRA levels showed a strong positive correlation with IL-8 levels and sebum production. It is worth noting that the production of sebum has a dominant effect on the scalp microbiome via the growth of microbes, leading to the formation of a biofilm, as evidenced by changes in the sRA levels. Furthermore, the sRA levels could be reduced through the use of antimicrobial agents, such as climbazole and hexamidine diisethionate (HD), as well as the manipulation of the physical properties of the scrubs used in scalp care products. These scalp care products could potentially disrupt the formation and accumulation of a biofilm on the scalp, providing strong evidence for the importance of considering the scalp microbiome and its interactions with sebum in the development of biofilms. Consequently, we suggested that the administration of anti-microbial agents, such as climbazole and HD, could be an effective strategy to alleviate biofilm accumulation for the maintenance of scalp health.