Topical adenosine increases the proportion of thick hair in Caucasian men with androgenetic alopecia

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.

Management of androgenic alopecia: a systematic review of the literature

We aimed to determine the efficacy of the various available oral, topical, and procedural treatment options for hair loss in individuals with androgenic alopecia. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic review of the National Library of Medicine was performed. Overall, 141 unique studies met our inclusion criteria. We demonstrate that many over the counter (e.g. topical minoxidil, supplements, low-level light treatment), prescription (e.g. oral minoxidil, finasteride, dutasteride), and procedural (e.g. platelet-rich plasma, fractionated lasers, hair transplantation) treatments successfully promote hair growth, highlighting the superiority of a multifaceted and individualized approach to management.

Anti-Hair Loss Effect of Adenosine Is Exerted by cAMP Mediated Wnt/β-Catenin Pathway Stimulation via Modulation of Gsk3β Activity in Cultured Human Dermal Papilla Cells

In the present study, we investigated the molecular mechanisms of adenosine for its hair growth promoting effect. Adenosine stimulated the Wnt/β-catenin pathway by modulating the activity of Gsk3β in cultured human dermal papilla cells. It also activated adenosine receptor signaling, increasing intracellular cAMP level, and subsequently stimulating the cAMP mediated cellular energy metabolism. The phosphorylation of CREB, mTOR, and GSK3β was increased. Furthermore, the expression of β-catenin target genes such as Axin2, Lef1, and growth factors (bFGF, FGF7, IGF-1) was also enhanced. The inhibitor study data conducted in Wnt reporter cells and in cultured human dermal papilla cells demonstrated that adenosine stimulates Wnt/β-catenin signaling through the activation of the adenosine receptor and Gsk3β plays a critical role in transmitting the signals from the adenosine receptor to β-catenin, possibly via the Gαs/cAMP/PKA/mTOR signaling cascade.

Efficacy comparison of monotherapies and combination therapies for androgenetic alopecia: A Bayesian network meta-analysis

Even though a variety of treatments for androgenetic alopecia (AGA) currently have been using in clinical, satisfactory therapeutic methods are still lacking. We aimed to compare and rank these treatments for AGA according to their differences in efficacy via Bayesian network meta-analysis, suggesting the optimal therapy for clinical utility to refer. A systematic search of PubMed, Embase, Web of Science, and Cochrane Library database was performed and we included eligible randomized controlled trials. We compared differences in treatment effects of monotherapies and combination therapies using the Bayesian network model. The average difference in alteration from baseline of hair density and hair diameter, and variation value (mean ± SD) between the pre- and post-intervention was selected for main outcome measure and secondary outcome measure. Total 49 RCTs involving 3133 patients and six interventions were included. Regardless of based on hair density or hair diameter, topical/systemic combined with adjunctive therapeutics had the best treatment efficacy among all interventions (MD: 40.11; 95% CrI 25.65-54.59), followed by topical combined with systemic medical therapeutics (MD: 36.41; 95% CrI 17.54-55.24). In addition, in terms of hair density, treatment efficacy had significant difference sequentially among topical medical therapeutics (MD: 22.15; 95% CrI 12.88-31.42), systemic medical therapeutics (MD: 19.91; 95% CrI 6.504-33.22), and adjunctive therapeutics (MD: 18.60; 95% CrI 8.020-29.10) compared to placebo. In recent years, combination therapies are showing significant promise as potential therapies. Taken together with the outcomes of this study, despite the specific mechanism of the effect of combination therapies was not clear and further studies are needed, it may be the best treatment for AGA.

Cheating on forensic hair testing? Detection of potential biomarkers for cosmetically altered hair samples using untargeted hair metabolomics

Hair analysis has become an integral part in forensic toxicological laboratories for e.g. assessment of drug or alcohol abstinence. However, hair samples can be manipulated by cosmetic treatments, altering drug concentrations which eventually leads to false negative hair test results. In particular oxidative bleaching of hair samples under alkaline conditions significantly affects incorporated drug concentrations. To date, current techniques to detect cosmetic hair adulterations bear limitations such as the implementation of cut-off values or the requirement of specialized instrumentations. As a new approach, untargeted hair metabolomics analysis was applied to detect altered, endogenous biomolecules that could be used as biomarkers for oxidative cosmetic hair treatments. For this, genuine hair samples were treated in vitro with 9% hydrogen peroxide (H2O2) for 30 minutes. Untreated and treated hair samples were analyzed using liquid-chromatography high-resolution time-of-flight mass spectrometry. In total, 69 metabolites could be identified as significantly altered after hair bleaching. The majority of metabolites decreased after bleaching, yet totally degraded metabolites were most promising as suitable biomarkers. The formation of biomarker ratios of metabolites decreasing and increasing in concentrations improved the discrimination of untreated and treated hair samples. With the results of this study, the high variety of identified biomarkers now offers the possibility to include single biomarkers or biomarker selections into routine screening methods for improved data interpretation of hair test results.

Efficacy of Off-Label Topical Treatments for the Management of Androgenetic Alopecia: A Review

Androgenetic alopecia (AGA) is characterized by non-scarring follicle miniaturization. Despite the success of approved therapies, commonly reported side effects and the need for continual use has led to the investigation of alternative therapies. The aim of this paper is to critically review the success of off-label, topical monotherapies for treatment of AGA in men. A literature search was conducted to obtain randomized, controlled and blinded studies that investigated off-label, topical, monotherapies in male patients. Hair density, hair diameter and hair growth were used to evaluate treatment success. Fourteen off-label topical therapies were investigated among the 16 studies that met inclusion criteria. Nine off-label therapies were reported to produce a significantly greater improvement in hair restoration parameters (e.g. mean change from hair count and hair diameter) as compared to placebo (p < 0.05 for all treatments). In two studies, procyanidin oligomers exhibited greater efficacy over vehicle with response to mean change in hair density (hairs/cm²) (p_s < 0.0001 at Week 24). In conclusion, prostaglandin analogs and polyphenols, such as latanoprost and procyanidin oligomers, can improve hair restoration parameters in male AGA patients, possibly through targeting mechanisms proposed in the etiology of AGA. The current evidence suggests short-term (24 weeks) use may provide benefit for hair loss patients; however, long-term efficacy and safety data are required.