Topical Treatment for Scarring and Non-Scarring Alopecia: An Overview of the Current Evidence

Can Plant Extracts Help Prevent Hair Loss or Promote Hair Growth? A Review Comparing Their Therapeutic Efficacies, Phytochemical Components, and Modulatory Targets

This narrative review aims to examine the therapeutic potential and mechanism of action of plant extracts in preventing and treating alopecia (baldness). We searched and selected research papers on plant extracts related to hair loss, hair growth, or hair regrowth, and comprehensively compared the therapeutic efficacies, phytochemical components, and modulatory targets of plant extracts. These studies showed that various plant extracts increased the survival and proliferation of dermal papilla cells in vitro, enhanced cell proliferation and hair growth in hair follicles ex vivo, and promoted hair growth or regrowth in animal models in vivo. The hair growth-promoting efficacy of several plant extracts was verified in clinical trials. Some phenolic compounds, terpenes and terpenoids, sulfur-containing compounds, and fatty acids were identified as active compounds contained in plant extracts. The pharmacological effects of plant extracts and their active compounds were associated with the promotion of cell survival, cell proliferation, or cell cycle progression, and the upregulation of several growth factors, such as IGF-1, VEGF, HGF, and KGF (FGF-7), leading to the induction and extension of the anagen phase in the hair cycle. Those effects were also associated with the alleviation of oxidative stress, inflammatory response, cellular senescence, or apoptosis, and the downregulation of male hormones and their receptors, preventing the entry into the telogen phase in the hair cycle. Several active plant extracts and phytochemicals stimulated the signaling pathways mediated by protein kinase B (PKB, also called AKT), extracellular signal-regulated kinases (ERK), Wingless and Int-1 (WNT), or sonic hedgehog (SHH), while suppressing other cell signaling pathways mediated by transforming growth factor (TGF)-β or bone morphogenetic protein (BMP). Thus, well-selected plant extracts and their active compounds can have beneficial effects on hair health. It is proposed that the discovery of phytochemicals targeting the aforementioned cellular events and cell signaling pathways will facilitate the development of new targeted therapies for alopecia.

Non-Cicatricial Alopecia and Its Association with Anthropometric Measurements and Nutritional Laboratory Markers

Alopecia constitutes one of the most common dermatological disorders, and its steadily increasing prevalence is a cause for concern. Alopecia can be divided into two main categories, cicatricial/scarring and non-cicatricial/non-scarring, depending on the causes of hair loss and its patterns. The aim of this study was to investigate the relationship between anthropometric and nutritional laboratory parameters in Caucasian adult women and men with non-cicatricial alopecia. A total of 50 patients (37 with non-cicatricial alopecia and 13 healthy controls) were included in the study. Clinical examination and scalp trichoscopy were performed. The anthropometric and nutritional laboratory parameters were collected and analyzed. No statistically significant differences in the laboratory findings were found. The patients with non-cicatricial alopecia were statistically significantly younger as compared to the controls. An elevated risk of hair loss, which was detected among the younger participants, might be associated with a modern lifestyle and the so-called 'Western diet'. It seems safe to assume that suboptimal nutrition and poor eating habits during childhood might constitute risk factors for early hair loss.

Toxicological assessment of minoxidil: A drug with therapeutic potential besides alopecia

Minoxidil is regularly prescribed for alopecia, and its therapeutic potential has expanded in recent times. However, few studies have been conducted to evaluate its toxicity, and controversial findings regarding its mutagenic activities remain unsolved. This study aimed to access cytotoxic, genotoxic, and mutagenic properties of minoxidil using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay, comet assay, and micronucleus test in mouse fibroblast (L929) cells and its point mutation induction potential in the Salmonella/microsome assay. Furthermore, an in vivo toxicity assessment was conducted in Caenorhabditis elegans. Minoxidil showed cytotoxicity at 2.0 mg/mL in MTT assay. Genotoxicity was observed after 3 h treatment in L929 cells using comet assay. No mutagenic effect was observed in both the micronucleus test and the Salmonella/microsome assay. The lethal dose 50 in C. elegans was determined to be 1.75 mg/mL, and a delay in body development was detected at all concentrations. In conclusion, minoxidil induces DNA damage only in early treatment, implying that this DNA damage may be repairable. This observation corroborates the absence of mutagenic activities observed in L929 cells and Salmonella typhimurium strains. However, the toxicity of minoxidil was evident in both C. elegans and L929 cells, underscoring the need for caution in its use.

An Update on Alopecia and its Association With Thyroid Autoimmune Diseases

Alopecia is comorbid with several illnesses, including various autoimmune conditions such as thyroid disease. Leukocyte-mediated inflammation of hair follicles in alopecia was first described over a century ago. However, the high prevalence of the role of thyroid autoimmune disease in the pathogenesis of alopecia has only recently come to light, together with a strong association between the two. Therefore, this review focuses on articles published between 2011 and 2022 on alopecia's association with thyroid autoimmune disease, and the mechanism behind it. In addition, it highlights the link between alopecia and thyroid cancer, as patients with alopecia have increased risk of thyroid cancer. In conclusion, this comprehensive, focused, scoping review will serve as a reference highlighting recent information on alopecia, exploring its association with thyroid autoimmune diseases.

Recent Trends in Macromolecule-Based Approaches for Hair Loss Treatment

Macromolecules are large, complex molecules composed of smaller subunits known as monomers. The four primary categories of macromolecules found in living organisms are carbohydrates, lipids, proteins, and nucleic acids; they also encompass a broad range of natural and synthetic polymers. Recent studies have shown that biologically active macromolecules can help regenerate hair, providing a potential solution for current hair regeneration therapies. This review examines the latest developments in the use of macromolecules for the treatment of hair loss. The fundamental principles of hair follicle (HF) morphogenesis, hair shaft (HS) development, hair cycle regulation, and alopecia have been introduced. Microneedle (MN) and nanoparticle (NP) delivery systems are innovative treatments for hair loss. Additionally, the application of macromolecule-based tissue-engineered scaffolds for the in vitro and in vivo neogenesis of HFs is discussed. Furthermore, a new research direction is explored wherein artificial skin platforms are adopted as a promising screening method for hair loss treatment drugs. Through these multifaceted approaches, promising aspects of macromolecules for future hair loss treatments are identified.

Follicle-Targeted Delivery of Betamethasone and Minoxidil Co-Entrapped in Polymeric and Lipid Nanoparticles for Topical Alopecia Areata Treatment

Alopecia areata is managed with oral corticosteroids, which has known side effects for patients. Given that a topical application of formulations containing a corticoid and a substance controlling hair loss progression could reduce or eliminate such adverse effects and increase the patient's adherence to the treatment, this study prepares polymeric and lipidic nanoparticles (PNPs and NLCs) to co-entrap minoxidil and betamethasone and compares the follicular drug delivery provided by topical application of these nanoparticles. The prepared PNPs loaded 99.1 ± 13.0% minoxidil and 70.2 ± 12.8% betamethasone, while the NLCs entrapped 99.4 ± 0.1 minoxidil and 80.7 ± 0.1% betamethasone. PNPs and NLCs presented diameters in the same range, varying from 414 ± 10 nm to 567 ± 30 nm. The thermal analysis revealed that the production conditions favor the solubilization of the drugs in the nanoparticles, preserving their stability. In in vitro permeation studies with porcine skin, PNPs provided a 2.6-fold increase in minoxidil penetration into the follicular casts compared to the control and no remarkable difference in terms of betamethasone; in contrast, NLCs provided a significant (specifically, a tenfold) increase in minoxidil penetration into the hair follicles compared to the control, and they delivered higher concentrations of betamethasone in hair follicles than both PNPs and the control. Neither PNPs nor NLCs promoted transdermal permeation of the drugs to the receptor solution, which should favor a topical therapy. Furthermore, both nanoparticles targeted approximately 50% of minoxidil delivery to the follicular casts and NLCs targeted 74% of betamethasone delivery to the hair follicles. In conclusion, PNPs and NLCs are promising drug delivery systems for enhancing follicular targeting of drugs, but NLCs showed superior performance for lipophilic drugs.

In Vitro Performance Analysis of a Minoxidil Thermosensitive Gel with Reduced Runoff for Eyebrow Hair Growth

There is a growing interest in innovative products for eyebrow hair loss treatment with fewer adverse effects. Nevertheless, a fundamental formulation aspect of preventing the fragile skin from the ocular region from being irritated is that the formulations remain restricted to the application region and do not run off. Consequently, the methods and protocols in drug delivery scientific research must be adapted to fulfill such performance analysis demand. Thus, this work aimed to propose a novel protocol to evaluate the in vitro performance of a topical gel formulation with a reduced runoff for minoxidil (MXS) delivery to eyebrows. MXS was formulated with 16% poloxamer 407 (PLX) and 0.4% of hydroxypropyl methylcellulose (HPMC). The sol/gel transition temperature, viscosity at 25 °C, and formulation runoff distance on the skin were evaluated to characterize the formulation. The release profile and skin permeation were evaluated in Franz vertical diffusion cells for 12 h and compared to a control formulation (4% PLX and 0.7% HPMC). Then, the formulation's performance at promoting minoxidil skin penetration with minimum runoff was evaluated in a vertical custom-made permeation template (divided into three areas: superior, middle, and inferior). The MXS release profile from the test formulation was comparable to that from the MXS solution and the control formulation. There was also no difference in the MXS amount that penetrated the skin in the permeation experiments in Franz diffusion cells using the different formulations (p > 0.05). However, the test formulation demonstrated a localized MXS delivery at the application site in the vertical permeation experiment. In conclusion, the proposed protocol could differentiate the test formulation from the control, attesting to its better performance in efficiently delivering MXS to the site of interest (middle third of application). The vertical protocol can be easily employed to evaluate other gels with a drip-free appeal.

Beyond the Hot Comb: Updates in Epidemiology, Pathogenesis, and Treatment of Central Centrifugal Cicatricial Alopecia from 2011 to 2021

Central centrifugal cicatricial alopecia (CCCA) is a form of scarring alopecia that predominantly affects middle-aged women of African descent. Recent data suggest a multifactorial etiology of CCCA that is influenced by environmental and genetic factors. Emerging evidence regarding the genetic basis of the condition may elucidate new therapies. While topical and intralesional steroids and tetracycline antibiotics are the mainstay of treatment, refractory cases may be considered for hair transplantation. Emerging therapies using platelet-rich plasma, botanical formulas, and cosmetic procedures have shown promising results for the future management of CCA. As recent notable advances in CCCA have been achieved, this review provides an update on the epidemiology, pathophysiology, and management of CCCA.

In Vitro and In Vivo Scalp Retention and Penetration of 99mTc-Minoxidil Solution

The present study assessed the effect of retention on ex vivo skin and in vivo scalp penetration of radiolabeled minoxidil formulations (5% w/v). Minoxidil was radiolabeled with technetium (99mTc) with an efficiency of 99.1% using 0.2% stannous chloride as reducing agent at pH 6 and incubation temperature of 40 °C. Three different 99mTc-minoxidil formulations were prepared using aqueous ethanolic solution as vehicle. Formulation A contains 99mTc-minoxidil dissolved in vehicle, formulation B contains 10% propylene glycol (PG) and formulation C contains 10% hydroxypropyl cellulose (HPC), in addition. Results showed that addition of HPC resulted in enhanced viscosity (400 mPa.s) and significantly higher ex vivo retention (p < 0.05) and permeation (0.75±0.12%, 8 h). PG does not improve the permeation and the results (0.44±0.05%, 8 h) were not significantly different from vehicle alone (0.40±0.05%, 8 h). The results of the in vivo human scalp studies corroborated with the ex vivo results and addition of hydroxypropyl cellulose (HPH) showed significantly higher (p < 0.05) scalp retention. Post 8 h application, scalp penetration in group treated with formulation C was nearly 2.8-fold and 2.2-fold higher than those treated with formulation A and B, respectively. Further, absence of minoxidil in systemic circulation during study duration indicates safety. In conclusion, our results showed that increasing contact time of minoxidil with scalp by modifying viscosity results in reduced frequency of application and improved efficacy.

Iontophoresis in dermal delivery: A review of applications in dermato-cosmetic and aesthetic sciences

OBJECTIVE

Iontophoresis is defined as the use of electric current to drive molecules across cell membranes through an electrolyte solution. In therapeutic context, it is used to facilitate the administration of bioactive substances, either systemically or locally. The technique presents various advantages and that is why it has been successfully used by a plethora of medical sciences. The constantly developing field of dermato-cosmetic science has also taken advantage of the possibilities offered by iontophoresis, aiming to enhance the delivery of the applied active ingredients and, thus, induce the desired cosmetic effects.

METHODS

The available literature was examined for evidence-based reports of safe and successful iontophoresis of pharmaceutical and cosmetic substances, in order to explore different iontophoretic applications in the field of dermato-cosmetic and dermato-aesthetic sciences.

CONCLUSION

Iontophoresis can be safely and successfully used in the treatment of ageing, photoageing, hyperpigmentation, oxidative stress, hair loss, hair removal, acne, acne sequelae and cellulite, providing many possibilities for enhanced treatment results.

An overview of the genetic aspects of hair loss and its connection with nutrition

Hair loss is a widespread concern in dermatology clinics, affecting both men's and women's quality of life. Hair loss can have many different causes, which are critical to identify in order to provide appropriate treatment. Hair loss can happen due to many variables, such as genetic factors or predisposition, vitamin and mineral deficiencies, skin problems, hair growth disorders, poor diet, hormonal problems, certain internal diseases, drug use, stress and depression, cosmetic factors, childbirth, and the chemotherapy process. Treatment for hair loss varies depending on the type of alopecia, deficiency, or excess of structures such as vitamins and minerals, and also on hair and skin structure. The Mediterranean diet is characterized by low amounts of saturated fat, animal protein, and high amounts of unsaturated fat, fiber, polyphenols, and antioxidants. The main nutrients found in the Mediterranean Diet are rich in antioxidant, anti-inflammatory components. It also has an important place in hair loss treatment, since recently treatment strategies have included polyphenols and unsaturated oils more and more frequently. The goal of this work was to review published articles examining alopecia and its types, the many micronutrients that affect alopecia, and the role of the Mediterranean diet in alopecia. The literature shows that little is known about hair loss, nutritional factors, and diet, and that the data collected are conflicting. Given these differences, research into the function of diet and nutrition in the treatment of baldness is a dynamic and growing topic.

Clinicopathological Features of Alopecia With an Emphasis on Etiology and Histopathological Characteristics of Scarring Alopecia

Introduction

Alopecia is a common dermatological condition with varied etiologies based on age, gender and geographic location. Non-cicatricial (non-scarring) alopecia is more common but often not biopsied. Alternatively, primary cicatricial (scarring) alopecia is diagnostically more challenging and more commonly biopsied to determine the etiology. In this study, we evaluated the clinicopathological characteristics of alopecia in our population.

Methods

We conducted a retrospective study at the Department of Histopathology, Liaquat National Hospital and Medical College, Pakistan. A total of 104 patients were enrolled in the study who underwent scalp biopsy for alopecia over a period of 11 years. Clinical data were obtained from clinical referral forms, which included age, sex of the patients and duration of the lesions. Three hematoxylin and eosin-stained tissue sections, along with periodic acid-Schiff (PAS), PAS with diastase and collagen stains were examined, and histopathological diagnosis was rendered.

Results

Our study demonstrated that alopecia was more prevalent among females, accounting for 73.1% of cases. Most of the patients belonged to the age group of <35 years (53.8%). The type of alopecia in 88.5% of the cases was scarring, while there were 11.5% cases of non-scarring alopecia. The most common diagnoses were discoid lupus erythematosus (DLE) (23.1%) and pseudopelade of Brocq (PB) (23.1%), followed by lichen planopilaris (LPP) (15.4%). A significant association was noted between the histological features and the diagnosis, as epidermal atrophy was the most common histological feature in most cases of DLE, followed by periadnexal infiltrates, lymphocytic infiltrates, follicular plugging and basement membrane thickening. In LPP, the most common histological features were perifollicular infiltrates and fibrosis. In PB, the frequently recurring histological features in most cases were the loss of sebaceous glands, dermal fibrosis and epidermal thinning.

Conclusion

In this study, we demonstrated the key role of skin punch biopsy and histology in determining the accurate etiology of scarring alopecia. We found discoid lupus erythematosus and pseudopelade of Brocq to be the most common causes of scarring alopecia, followed by lichen planopilaris.

A Comprehensive Review of Natural Alternatives for Treatment of Alopecia with an Overview of Market Products

Alopecia or hair loss is a widespread issue that has significant effects on personal well-being for both genders nationally and internationally. In addition, alopecia causes extreme emotional stress and negatively impacts the psychological health and self-esteem of cancer patients suffering from chemotherapy-induced alopecia. Unfortunately, available synthetic medications are costly, invasive, or have extreme adverse effects. On the contrary, natural and herbal hair loss products are widely available in the local and international markets in variable pharmaceutical forms with different mechanisms of action, namely, androgen antagonists, nutritional supplements, vasodilators, and 5α-reductase inhibitors or dihydrotestosterone blockers. Thus, it is of great importance to encourage researchers to investigate these natural alternatives that can act as potent therapeutic agents having diverse mechanisms of action as well as limited side effects. Currently, natural remedies are considered a fast-rising pharmaceutical segment with demand from a wide range of consumers. In this study, we present a review of reported herbal remedies and herb combinations recommended for hair loss and their mode of action, along with an overview of available market products and formulations, their composition, and declared effects. In addition, a general outline of the different forms of alopecia, its causes, and recommended treatments are mentioned as well. This was all done with the aim of assisting further studies with developing standardized natural formulations for alopecia as many were found to lack standardization of their bioactive ingredients and efficiency confirmation.

Nanostructured lipid carriers loaded with an association of minoxidil and latanoprost for targeted topical therapy of alopecia

Alopecia is a condition associated with different etiologies, ranging from hormonal changes to chemotherapy, that affects over 80 million people in the USA. Nevertheless, there are currently few FDA-approved drugs for topical treatment, and existing formulations still present skin irritation issues, compromising treatment adherence. This work aimed to develop a safe formulation based on nanostructured lipid carriers (NLC) that entrap an association of minoxidil and latanoprost and target drug delivery to the hair follicles. To do so, thermal techniques combined with FTIR were used to assess the chemical compatibility of the proposed drug association. Then, NLC with 393.5 ± 36.0 nm (PdI<0.4) and +22.5 ± 0.2 mV zeta potential were produced and shown to entrap 86.9% of minoxidil and 99.9% of latanoprost efficiently. In vitro, the free drug combination was indicated to exert positive effects over human primary epidermal keratinocytes, supporting cell proliferation, migration and inducing the mRNA expression of MKI67 proliferation marker and VEGF - a possible effector for minoxidil-mediated hair growth. Interestingly, such a favorable drug combination profile was optimized when delivered using our NLC. Furthermore, according to the HET-CAM and reconstructed human epidermis assays, the nanoformulation was well tolerated. Finally, drug penetration was evaluated in vitro using porcine skin. Such experiments indicated that the NLC could be deposited preferentially into the hair follicles, causing a considerable increase in the penetration of the two drugs in such structures, compared to the control (composed of the free compounds) and generating a target-effect of approximately 50% for both drugs. In summary, present results suggest that hair follicle-targeted delivery of the minoxidil and latanoprost combination is a promising alternative to treat alopecia.

Tectoridin Stimulates the Activity of Human Dermal Papilla Cells and Promotes Hair Shaft Elongation in Mouse Vibrissae Hair Follicle Culture

To search hair growth-promoting herbal extract, a screening platform of having HEK293T fibroblast being transfected with pTOPFLASH DNA construct was developed over a thousand of herbal extracts and phytochemicals were screened. One of the hits was ethanolic extract of Rhizoma Belamcandae, the rhizome of Belamcanda chinensis (L.) DC. Tectoridin, an isoflavone from Rhizoma Belamcandae, was shown to be responsible for this activation of promoter construct, inducing the transcription of pTOPFLASH in the transfected fibroblasts in a dose-dependent manner. The blockage by DKK-1 suggested the action of tectoridin could be mediated by the Wnt receptor. The hair growth-promoting effects of tectoridin were illustrated in human follicular dermal papilla cells and mouse vibrissae organ cultures. In tectoridin-treated dermal papilla cultures, an activation of Wnt signaling was demonstrated by various indicative markers, including TCF/LEF1 transcriptional activity, nuclear translocation of β-catenin, expressions level of mRNAs encoding axin-related protein, (AXIN2), β-catenin, lymphoid enhancer-binding factor-1 (LEF-1), insulin-like growth factor 1 (IGF-1) and alkaline phosphatase (ALP). In addition, an increase of hair shaft elongation was observed in cultured mouse vibrissae upon the treatment of tectoridin. Tectoridin, as well as the herbal extract of Rhizoma Belamcandae, possesses hair promoting activity, which deserves further development.

Optimization and Transfollicular Delivery of Finasteride-Loaded Proniosomes for Hair Growth Stimulation in C57BL/6Mlac Mice

The study aimed to develop the finasteride-loaded proniosome (FLP) to enhance the transfollicular delivery of finasteride (FN). The response surface methodology (RSM) combined with central composite design (CCD) with three independent variables (FN concentrations, total lipid content, and cholesterol content) was used to optimize the FLP preparation. The particles size, zeta potential, entrapment efficiency, and drug loading capacity of the FLP were analyzed. The transfollicular delivery of the optimum formulation was investigated in vitro. In vivo hair growth stimulation study was performed on C57BL/6Mlac mice dorsal areas. The Draize primary skin irritation test for erythema and edema was performed in the New Zealand white rabbit skin. The optimum FLP consists of 5.0 mM of FN, 10.1 mM of total lipid content, and 50.0% of the cholesterol in the total lipid. The prepared proniosome delivered the FN significantly (p < 0.05), compared to the naked finasteride solution in a dose- and time-dependent manner. The FLP treatment significantly increases the number and size of hair follicles in a dose-dependent manner. The efficiency of 1% FLP was comparable to the 2% minoxidil solution. The FLP exhibited no skin irritation after 72 h. Therefore, the results demonstrated that the FLP could stimulate hair growth via a transfollicular delivery system.