Niacinamide Down-Regulates the Expression of DKK-1 and Protects Cells from Oxidative Stress in Cultured Human Dermal Papilla Cells

Revitalizing Effect on the Scalp After Injection with a Mechanically Stabilized Hyaluronic Acid Complex in Subjects with Androgenetic Alopecia

Background: Treatments for androgenetic alopecia (AGA) include different drugs, but a treatment based on stabilized hyaluronic acid has not been tested. The aim of this study is to clinically evaluate the effect of six sessions of injections using a hyaluronic acid compound supplemented with vitamins, ions, and amino acids (CH) on hair density and quality in volunteers. Methods: For this purpose, twenty-six healthy volunteers of both sexes with moderate AGA were injected with 3 mL of CH using the micro-papule technique. All received six CH sessions at two-week intervals. Hair loss, hair thickness, and shine were assessed using macro-photographs. A follow-up questionnaire was given to the volunteers at 40 days and at 90 days after the last treatment to determine their level of satisfaction. In addition, a dermatological control was carried out to assess the tolerance of the treatment applied. Results: The results indicate that, after treatment with CH, there is a significant improvement in the thickness, shine, and density of scalp hair, and that the treatment significantly reduces hair loss on the scalp. On a dermatological level, the tolerability of the treatment was excellent with no complications observed. In total, 88.5% of the volunteers indicated that CH treatment improved their appearance. In summary, it can be said that CH treatment reduces hair loss and promotes hair growth. Conclusions: It is suggested that this treatment is effective in reducing the signs and symptoms of alopecia.

Senomorphic activity of a combination of niacinamide and hyaluronic acid: correlation with clinical improvement of skin aging

Intrinsic and extrinsic factors, including lifestyle and sun exposure, can contribute to cell senescence, which impairs skin homeostasis, that may in turn lead to skin aging. Senescent cells have a specific secretome, called the senescence-associated secretory phenotype (SASP) that includes MMPs, CXCLs and S100A8/9. Reducing the SASP with senotherapeutics is a promising strategy to reduce skin aging. Here we evaluated the effect of a formula containing niacinamide and hyaluronic acid, which are known to limit senescence and skin aging. We conducted three different studies. (1) Ex vivo explants treated with the formula had more collagen and glycosaminoglycan. (2) In a clinical trial with forty-four women, two months of treatment improved fine lines, wrinkles, luminosity, smoothness, homogeneity, and plumpness. (3) In a third study on thirty women, we treated one arm for two months and took skin biopsies to study gene expression. 101 mRNAs and 13 miRNAs were differentially expressed. We observed a likely senomorphic effect, as there was a decrease in many SASP genes including MMP12 and CXCL9 and a significant downregulation of autocrine signaling genes: S100A8 and S100A9. These pharmaco-clinical results are the first to demonstrate the senomorphic properties of an effective anti-aging formula in skin.

Hair Thickness Growth Effect of Adenosine Complex in Male-/Female-Patterned Hair Loss via Inhibition of Androgen Receptor Signaling

Aging (senescence) is an unavoidable biological process that results in visible manifestations in all cutaneous tissues, including scalp skin and hair follicles. Previously, we evaluated the molecular function of adenosine in promoting alopecia treatment in vitro. To elucidate the differences in the molecular mechanisms between minoxidil (MNX) and adenosine, gene expression changes in dermal papilla cells were examined. The androgen receptor (AR) pathway was identified as a candidate target of adenosine for hair growth, and the anti-androgenic activity of adenosine was examined in vitro. In addition, ex vivo examination of human hair follicle organ cultures revealed that adenosine potently elongated the anagen stage. According to the severity of alopecia, the ratio of the two peaks (terminal hair area/vellus hair area) decreased continuously. We further investigated the adenosine hair growth promoting effect in vivo to examine the hair thickness growth effects of topical 5% MNX and the adenosine complex (0.75% adenosine, 1% penthenol, and 2% niacinamide; APN) in vivo. After 4 months of administration, both the MNX and APN group showed significant increases in hair density (MNX + 5.01% (p < 0.01), APN + 6.20% (p < 0.001)) and thickness (MNX + 5.14% (p < 0.001), APN + 10.32% (p < 0.001)). The inhibition of AR signaling via adenosine could have contributed to hair thickness growth. We suggest that the anti-androgenic effect of adenosine, along with the evaluation of hair thickness distribution, could help us to understand hair physiology and to investigate new approaches for drug development.

Oxidative stress in hair follicle development and hair growth: Signalling pathways, intervening mechanisms and potential of natural antioxidants

Hair follicle development and hair growth are regulated by multiple factors and multiple signalling pathways. The hair follicle, as an important skin appendage, is the basis for hair growth, and it has the functions of safeguarding the body, perceiving the environment and regulating body temperature. Hair growth undergoes a regular hair cycle, including anagen, catagen and telogen. A small amount of physiological shedding of hair occurs under normal conditions, always in a dynamic equilibrium. Hair loss occurs when the skin or hair follicles are stimulated by oxidative stress, inflammation or hormonal disorders that disrupt the homeostasis of the hair follicles. Numerous researches have indicated that oxidative stress is an important factor causing hair loss. Here, we summarize the signalling pathways and intervention mechanisms by which oxidative stress affects hair follicle development and hair growth, discuss existing treatments for hair loss via the antioxidant pathway and provide our own insights. In addition, we collate antioxidant natural products promoting hair growth in recent years and discuss the limitations and perspectives of current hair loss prevention and treatment.

Phloroglucinol Enhances Anagen Signaling and Alleviates H2O2-Induced Oxidative Stress in Human Dermal Papilla Cells

Phloroglucinol (PG) is one of the abundant isomeric benzenetriols in brown algae. Due to its polyphenolic structure, PG exhibits various biological activities. However, the impact of PG on anagen signaling and oxidative stress in human dermal papilla cells (HDPCs) is unknown. In this study, we investigated the therapeutic potential of PG for improving hair loss. A non-cytotoxic concentration of PG increased anagen-inductive genes and transcriptional activities of β-Catenin. Since several anagen-inductive genes are regulated by β-Catenin, further experiments were performed to elucidate the molecular mechanism by which PG upregulates anagen signaling. Various biochemical analyses revealed that PG upregulated β-Catenin signaling without affecting the expression of Wnt. In particular, PG elevated the phosphorylation of protein kinase B (AKT), leading to an increase in the inhibitory phosphorylation of glycogen synthase kinase 3 beta (GSK3β) at serine 9. Treatment with the selective phosphoinositide 3-kinase/AKT inhibitor, LY294002, restored the increased AKT/GSK3β/β-Catenin signaling and anagen-inductive proteins induced by PG. Moreover, conditioned medium from PG-treated HDPCs promoted the proliferation and migration of human epidermal keratinocytes via the AKT signaling pathway. Subsequently, we assessed the antioxidant activities of PG. PG ameliorated the elevated oxidative stress markers and improved the decreased anagen signaling in hydrogen peroxide (H2O2)-induced HDPCs. The senescence-associated β-galactosidase staining assay also demonstrated that the antioxidant abilities of PG effectively mitigated H2O2-induced senescence. Overall, these results indicate that PG potentially enhances anagen signaling and improves oxidative stress-induced cellular damage in HDPCs. Therefore, PG can be employed as a novel therapeutic component to ameliorate hair loss symptoms.

β-Nicotinamide Mononucleotide Promotes Cell Proliferation and Hair Growth by Reducing Oxidative Stress

β-Nicotinamide mononucleotide (NMN) has shown promising effects on intestinal health, and it is extensively applied as an anti-aging and Alzheimer's disease therapeutic, due to its medicinal properties. The effects of NMN on the growth of mouse hair were observed after hair removal. The results indicated that NMN can reverse the state of hair follicle atrophy, hair thinning, and hair sparsity induced by dihydrotestosterone (DHT), compared to that of minoxidil. In addition, the action mechanisms of NMN promoting hair growth in cultured human dermal papilla cells (HDPCs) treated with DHT were investigated in detail. The incubation of HDPCs with DHT led to a decrease in cell viability and the release of inflammatory mediators, including interleukin-6 (IL-6), interleukin-1Beta (IL-1β) and tumor necrosis factor Alpha (TNF-α). It was found that NMN can significantly lower the release of inflammatory factors induced by DHT in HDPCs. HDPCs cells are protected from oxidative stress damage by NMN, which inhibits the NF-κB p65 inflammatory signaling pathway. Moreover, the levels of androgen receptor (AR), dickkopf-1 (DKK-1), and β-catenin in the HDPCs were assessed using PCR, indicating that NMN can significantly enhance the expression of VEGF, reduced IL-6 levels and suppress the expression of AR and DKK-1, and notably increase β-catenin expression in DHT-induced HDPCs.

Morphogenesis, Growth Cycle and Molecular Regulation of Hair Follicles

As one of the main appendages of skin, hair follicles play an important role in the process of skin regeneration. Hair follicle is a tiny organ formed by the interaction between epidermis and dermis, which has complex and fine structure and periodic growth characteristics. The hair growth cycle is divided into three continuous stages, growth (anagen), apoptosis-driven regression (catagen) and relative quiescence (telogen). And The Morphogenesis and cycle of hair follicles are regulated by a variety of signal pathways. When the signal molecules in the pathways are abnormal, it will affect the development and cycle of hair follicles, which will lead to hair follicle-related diseases.This article will review the structure, development, cycle and molecular regulation of hair follicles, in order to provide new ideas for solving diseases and forming functional hair follicle.