Sulforaphane promotes murine hair growth by accelerating the degradation of dihydrotestosterone

A Natural Inhibitor, 1'S-1'-Acetoxychavicol Acetate, Against Testosterone-Induced Alopecia via NADPH Oxidase Regulation

Androgenetic alopecia is associated with testosterone-mediated anagen-to-catagen transition and matrix keratinocyte apoptosis in hair follicle cells. Activation of Nox isozymes is involved in testosterone-mediated keratinocyte apoptosis, leading to androgenetic alopecia. This indicates that Nox isozymes can serve as therapeutic targets for androgenetic alopecia. The isolated compounds from natural products were screened to evaluate their ROS-inhibition efficacy and it was found that 1'S-1'-acetoxychavicol acetate (ACA, 26), a natural compound isolated from Alpinia galanga (L.) Willd. (Zingiberaceae), exhibits inhibitory activity on Nox isozymes. Nox inhibition by ACA suppressed testosterone-dependent H2O2 generation and cell death in keratinocytes. Incubation with ACA in human hair follicle organ culture mitigated testosterone-dependent suppression of hair growth. We validated that ACA regulates androgenetic alopecia in a mouse model. Local application of ACA on the dorsal skin in an androgenetic alopecia model of C57BL/6 mice significantly suppressed testosterone-induced hair loss in a dose-dependent manner. Moreover, hair follicle length in ACA-treated mice was enhanced compared to that in control mice. These findings provide a molecular mechanism in which ACA inhibits Nox activity in hair follicle cells, indicating its potential as an effective treatment of AGA.

Innovative strategies for the discovery of new drugs against androgenetic alopecia

INTRODUCTION

Androgenetic alopecia (AGA) is the most common cause of hair loss worldwide. The significant psychological and social impact of AGA continues to drive demand for more effective treatments beyond the limited options currently available.

AREAS COVERED

The authors review the key components of AGA pathogenesis, as well as current treatments, and therapeutic techniques under development. Innovative strategies for AGA drug discovery are still needed, given the significant unmet medical needs and the limited efficacy of both current and emerging treatments. The authors outline relevant preclinical models, such as hair follicle (HF) cell cultures, 3D spheroids, organoids, follicle explants, and animal models, highlighting their advantages and limitations in AGA research. Finally, they summarize the primary objectives in AGA treatment development, including direct hair growth promotion, interference with androgen signaling, and HF rejuvenation, identifying key pathogenesis intervention points for treatment development.

EXPERT OPINION

Developing better in vitro models, possibly using induced pluripotent stem cell (iPSC) systems, could greatly accelerate drug discovery. Similarly, a superior in vivo model could significantly expedite drug discovery. Near future development research should focus on drug delivery improvements. Longer term, treatments targeting AGA's underlying pathophysiology and promoting HF rejuvenation or true regeneration would provide the most benefit to prospective patients.

Functional Food Nutrients, Redox Resilience Signaling and Neurosteroids for Brain Health

The interplay between functional food nutrients and neurosteroids has garnered significant attention for its potential to enhance stress resilience in health and/or disease. Several bioactive nutrients, including medicinal herbs, flavonoids, and bioavailable polyphenol-combined nanoparticles, as well as probiotics, vitamin D and omega-3 fatty acids, have been shown to improve blood-brain barrier (BBB) dysfunction, endogenous neurosteroid homeostasis and brain function. These nutrients can inhibit oxidative stress and neuroinflammation, which are linked to the pathogenesis of various neurological disorders. Interestingly, flavonoids exhibit dose-dependent effects, activating the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway at the physiological/low dose (neurohormesis). This leads to the upregulation of antioxidant phase II genes and proteins such as heme oxygenase-1 (HO-1) and sirtuin-1 (Sirt1), which are activated by curcumin and resveratrol, respectively. These adaptive neuronal response mechanisms help protect against reactive oxygen species (ROS) and neurotoxicity. Impaired Nrf2 and neurosteroid hormone signaling in the brain can exacerbate selective vulnerability to neuroinflammatory conditions, contributing to the onset and progression of neurodegenerative and psychiatric disorders, including Alzheimer's disease, anxiety and depression and other neurological disorders, due to the vulnerability of neurons to stress. This review focuses on functional food nutrients targeting Nrf2 antioxidant pathway and redox resilience genes to regulate the neurosteroid homeostasis and BBB damage associated with altered GABAergic neurotransmission. By exploring the underlying molecular mechanisms using innovative technologies, we aim to develop promising neuroprotective strategies and personalized nutritional and neuroregenerative therapies to prevent or attenuate oxidative stress and neuroinflammation, ultimately promoting brain health.

Cell-free fat extract restores hair loss: a novel therapeutic strategy for androgenetic alopecia

BACKGROUND

Androgenetic alopecia (AGA) is one of the most common hair loss diseases worldwide. However, current treatments including medicine, surgery, and stem cells are limited for various reasons. Cell-free fat extract (CEFFE), contains various cell factors, may have potential abilities in treating AGA. This study aims to evaluate the safety, effectiveness and the underlying mechanism of CEFFE in treating AGA.

METHODS

Sex hormone evaluation, immunogenicity assay and genotoxicity assay were conducted for CEFFE. In vivo study, male C57BL/6 mice were injected subcutaneously with dihydrotestosterone (DHT) and were treated with different concentration of CEFFE for 18 days (five groups and n = 12 in each group: Control, Model, CEFFELow, CEFFEMiddle, CEFFEHigh). Anagen entry rate and hair coverage percentage were analyzed through continuously taken gross photographs. The angiogenesis and proliferation of hair follicle cells were evaluated by hematoxylin-eosin, anti-CD31, and anti-Ki67 staining. In vitro study, dermal papilla cells (DPCs) were incubated with different concentrations of CEFFE, DHT, or CEFFE + DHT, followed by CCK-8 assay and flow cytometry to evaluate cell proliferation cycle and apoptosis. The intracellular DHT level were assessed by enzyme-linked immunosorbent assay. The expression of 5α-reductase type II, 3α-hydroxysteroid dehydrogenase and androgen receptor were assessed through reverse transcription-quantitative polymerase chain reaction (RT-qPCR) or/and western blot.

RESULTS

In CEFFE-treated mice, an increase in the anagen entry rate and hair coverage percentage was observed. The number of CD31-positive capillaries and Ki67-positive cells were increased, suggesting that CEFFE promoted the proliferation of DPCs, modulated the cell cycle arrest, inhibited apoptosis caused by DHT, reduced the intracellular concentration of DHT in DPCs, and downregulated the expression of AR.

CONCLUSIONS

CEFFE is a novel and effective treatment option for AGA through producing an increased hair follicle density and hair growth rate. The proposed mechanisms are through the DHT/AR pathway regulation and regional angiogenesis ability.

The medicinal activity of lyophilized aqueous seed extract of Lepidium sativum L. in an androgenic alopecia model

This study evaluated the topical effect of Lepidium sativum lyophilized seed extract (LSLE) towards Sustanon-induced alopecia in male adult Wistar albino rats in vivo, compared to minoxidil topical reference standard drug (MRD). LC-MS/MS together with molecular networking was used to profile the metabolites of LSLE. LSLE treated group revealed significant changes in alopecia related biomarkers, perturbation of androgenic markers; decline in testosterone level and elevation in 5α-reductase (5-AR); decline in the cholesterol level. On the other hand, LSLE treated group showed improvement in vascular markers; CTGF, FGF and VEGF. Groups treated topically with minoxidil and LSLE showed significant improvement in hair length. LC-MS/MS profile of LSLE tentatively identified 17 constituents: mainly glucosinolates, flavonoid glycosides, alkaloids and phenolic acids. The results point to the potential role of LSLE in the treatment of alopecia through decreasing 5(alpha)-dihydrotestosterone levels. Molecular docking was attempted to evaluate the probable binding mode of identified compounds to androgen receptor (PDB code: 4K7A).

Comorbidities in Androgenetic Alopecia: A Comprehensive Review

Androgenetic alopecia is the most common form of hair loss, affecting 85% of men and 40% of women. Androgenetic alopecia is a disease caused by multiple factors, such as genetics, hormones, and systemic diseases; however, the exact cause remains undetermined. Recent studies have found that it is associated with a high incidence of endocrine diseases and other comorbidities. It may not only be a skin disease but also an early signal of underlying systemic diseases. Effective management requires timely diagnosis and treatment initiation. However, in current clinical practice, androgenetic alopecia is still not fully understood or treated. Recognizing the true physical, social, and emotional burden of androgenic alopecia, as well as its associated comorbidities, is the first step in improving the prognosis of affected patients. This review aimed to gather the known pathological factors and provide a reference for clinical physicians to understand androgenetic alopecia and its comorbidities in depth, thereby enabling early recognition of the underlying systemic diseases and providing timely treatment.

Sulforaphane, L-Menthol, and Dexpanthenol as a Novel Active Cosmetic Ingredient Composition for Relieving Hair Loss Symptoms

Sulforaphane increases the expression of the dihydrotestosterone (DHT)-degrading enzyme, 3α-hydroxysteroid dehydrogenase (3α-HSD) in the liver, which accelerates DHT degradation, thereby inhibiting hair loss in the animal model. In this study, we elucidated its underlying mechanism and demonstrated that sulforaphane has hair loss inhibitory functions in RAW264.7 macrophage cells and Hepa1c1c7 cells at the cellular and gene levels. The gene expression level of an isoform of 3α-HSD, Akr1c2, increased in a dose-dependent manner when these cells were treated with sulforaphane, but there were no significant differences at the gene levels of Akr1c2 and Dhrs9 for the negative control mixture of biotin, dexpanthenol, and L-menthol. These studies indicated that sulforaphane is involved in regulating the gene expression of Akr1c2. To further determine whether this hair product has effects on alleviating hair loss symptoms, clinical trials were also conducted for 18 weeks. We performed a visual evaluation of the parietal and frontal lines of 23 patients before and after using the product, and then calculated the total number of hairs. This clinical study showed that the parietal lines and bangs visually improved and the number of hairs increased by 6.71% from before using the test product to 18 weeks after using the test product. Taken together, these cellular and clinical studies strongly suggest that sulforaphane may be an active ingredient that significantly alleviates hair loss symptoms.

An appraisal of laboratory models of androgenetic alopecia: A systematic review

Background

Androgenetic alopecia (AGA) is the most common form of non‐scarring alopecia in humans. Several studies have used different laboratory models to study the pathogenesis and interventions for AGA. These study models have proved beneficial and have led to the approval of two drugs. However, the need to build on existing knowledge remains by examining the relevance of study models to the disease.

Objective

We sought to appraise laboratory or pre‐clinical models of AGA.

Method

We searched through databases (PubMed, ScienceDirect, Web of Science, World CAT, Scopus and Google Scholar) for articles on AGA‐related studies from 1942 to March 2019 with a focus on study models.

Results

The search rendered 101 studies after screening and deduplication. Several studies (70) used in vitro models, mostly consisting of two‐dimensional monolayer cells for experiments involving the characterization of androgen and 5‐alpha reductase (5AR) and inhibition thereof, the effects of dihydrotestosterone (DHT) and biomarker(s) of AGA. Twenty‐seven studies used in vivo models of mice and monkeys to investigate DHT synthesis, the expression and inhibition of 5AR and hair growth. Only four studies used AGA‐related or healthy excisional/punch biopsy explants as ex vivo models to study the action of 5AR inhibitors and AGA‐associated genes. No study used three‐dimensional [3‐D] organoids or organotypic human skin culture models.

Conclusion

We recommend clinically relevant laboratory models like human or patient‐derived 3‐D organoids or organotypic skin in AGA‐related studies. These models are closer to human scalp tissue and minimize the use of laboratory animals and could ultimately facilitate novel therapeutics.

Clinical Patterns of Hair Loss in Men: Is Dihydrotestosterone the Only Culprit?

A number of pathways and factors including oxidative stress, inflammation, prostaglandins, vasculogenesis, Wnt/β-catenin, and transforming growth factor-β have been shown to be important in male androgenetic alopecia. There is limited but increasing evidence of the potential usefulness of antioxidants, anti-inflammatory agents, prostaglandins, and growth factors for treating of androgenetic alopecia. Lifestyle factors and comorbidities including cardiovascular risk factors have been shown to be associated with male androgenetic alopecia. Further study of these pathways, factors, and comorbidities is needed to better understand the pathophysiology, find potentially useful therapeutic targets, and ensure a comprehensive approach to the management of androgenetic alopecia in men.

Brassica oleracea extract, glucosinlates, and sulforaphane promote hair growth in vitro and ex vivo

BACKGROUND

Androgenic alopecia (AGA) is the most common type of hair loss, in which dihyrotestosterone (DHT) plays a crucial role via modulating androgen receptors in hair follicles.

AIMS

The current objective is to search for new therapy of AGA.

METHODS

In the present study, we investigated the effects of sulforaphane, its precursor glucosinlates and glucosinlates-enriched Brassica oleracea L.var.italic Planch extract (BOE) on the growth of hair follicle and the related matrix cell viability, as well as the possible underlying mechanisms in vitro and ex vivo.

RESULTS

We observed that BOE, glucosinlates, and sulforaphane can prevent the testosterone-induced inhibition of dermal papilla (DP) cells viability. BOE and sulforaphane can even hinder the testosterone-induced inhibition of HaCaT cells viability. Moreover, BOE, glucosinlates, and sulforaphane can up-regulate the cytokeratin gene expression in HaCaT cells, prevent the increase in Bax gene levels induced by testosterone in DP, and promote the growth of hair follicle of mice. These effects can be linked to the enhancement of DP and HaCaT cells activities and the prevention of the testosterone-induced cell apoptosis of DP cells.

CONCLUSIONS

Taken together, BOE, glucosinlates, and sulforaphane can promote the growth of hair follicle of mice and can be used as potential treatment agents for androgenic alopecia.

iNOS inhibits hair regeneration in obese diabetic (ob/ob) mice

Previous studies have shown that androgenic alopecia is associated with metabolic syndrome and diabetes. However, the detailed mechanism whereby diabetes causes alopecia still remains unclear. We focused on the inflammatory response that is caused by diabetes or obesity, given that inflammation is a risk factor for hair loss. Inducible nitric oxide synthase (iNOS) is known to be upregulated under conditions of acute or chronic inflammation. To clarify the potential role of iNOS in diabetes-related alopecia, we generated obese diabetic iNOS-deficient (ob/ob; iNOS-KO mice). We observed that ob/ob; iNOS-KO mice were potentiated for the transition from telogen (rest phase) to anagen (growth phase) in the hair cycle compared with iNOS-proficient ob/ob mice. To determine the effect of nitric oxide (NO) on the hair cycle, we administered an iNOS inhibitor intraperitoneally (compound 1400 W, 10 mg/kg) or topically (10% aminoguanidine) in ob/ob mice. We observed that iNOS inhibitors promoted anagen transition in ob/ob mice. Next, we administered an NO donor (S-nitrosoglutathione, GSNO), to test whether NO has the telogen elongation effects. The NO donor was sufficient to induce telogen elongation in wild-type mice. Together, our data indicate that iNOS-derived NO plays a role in telogen elongation under the inflammatory conditions associated with diabetes in mice.

Prostaglandin D2 Uses Components of ROS Signaling to Enhance Testosterone Production in Keratinocytes

Elevated levels of prostaglandin D2 (PGD2) have been shown to be present in the bald scalp of androgenic alopecia (AGA) patients and to functionally inhibit hair growth. However, its precise mechanism in AGA has yet to be clearly defined. Although testosterone plays a critical role in the initiation and progression of AGA, the existence of a possible link between PGD2 and testosterone in skin has not been investigated. Here we show that human keratinocytes treated with PGD2 show enhanced capacity to convert the weak androgen, androstenedione, to testosterone. At the same time, treatment with PGD2 induced reactive oxygen species as indicated by generation of the lipid peroxidation product, 4-hydroxynonenal. To determine whether these two events are linked, we used the reactive oxygen species scavenger N-acetyl-cysteine, which blocked the enhanced testosterone production from PGD2-treated keratinocytes. Our study suggests the existence of a possible crosstalk between the PGD2-reactive oxygen species axis and testosterone metabolism in keratinocytes. Thus, we propose that AGA patients might benefit from the use of N-acetyl-cysteine or other antioxidants as a supplement to currently available or emerging AGA therapies such as finasteride, minoxidil, and PGD2 receptor blockers.