ABSTRACT
Androgenetic alopecia (AGA) is the most common form of hair loss disorder. As the prevalence of AGA rises, the demand for AGA treatments is rising accordingly, prompting research to identify therapeutic candidates to treat AGA. Because AGA is caused by crosstalk among multiple hair follicle (HF) cell components, understanding the effects of candidate molecules on HF cells is essential to determining therapeutic candidates for treatment. To date, research has centered on HF dermal papilla and outer root sheath cells and has indicated that the hair growth effects of candidate substances may be mediated via alterations in several signaling pathways and signature genes in these HF cells. In more integrative evaluations, the HF unit is used as an ex vivo organ culture model to verify the effects of therapeutic candidates. Animal models have also been used to evaluate the effects of candidate substances. The main outcomes used to evaluate the effects of candidate substances are 1) changes in HF growth rates in vitro, 2) anagen induction capabilities, and 3) the effects of androgen modulation. This article reviews a series of methods used to evaluate the hair growth-promoting effects of candidate substances, providing an overview of cell assays, organs, and animal models used in AGA research in order to facilitate AGA research moving forward.
Subject(s)
Alopecia/drug therapy , Dermatologic Agents/pharmacology , Hair Follicle/drug effects , Models, Animal , Organ Culture Techniques/methods , Alopecia/pathology , Animals , Dermatologic Agents/therapeutic use , Drug Evaluation, Preclinical/methods , Hair Follicle/cytology , Hair Follicle/growth & development , Hair Follicle/pathology , Humans , Signal Transduction/drug effectsABSTRACT
BACKGROUND: The regeneration or revascularization of blood vessels after pulsed dye laser (PDL) treatment is one of the causes of treatment failures of cutaneous capillary malformations (CM). Recently, topical administration of rapamycin was introduced as a possible adjunctive therapeutic option to minimize postlaser revascularization in facial CM. OBJECTIVES: We evaluated the effect of combined use of 1% topical rapamycin with PDL compared to PDL alone in cutaneous CM of trunk or extremities and tried to identify the optimal duration of topical rapamycin application. METHODS: Three adjacent areas of cutaneous CM that had never been treated before were selected in each patient and underwent the following regimens: (A) PDL + vehicle for 8 weeks post-PDL; (B) PDL + topical rapamycin for 1-week post-PDL and (C) PDL + topical rapamycin for 8 weeks post-PDL. Each test site was treated by PDL for two sessions with 8 weeks interval. RESULTS: Only one of six patients showed clinical improvement with combined rapamycin treatment. Overall, there was no statistically significant difference in erythema and blanching rate among PDL alone and combined rapamycin regimens. CONCLUSION: One percent topical rapamycin does not seem to be effective as a treatment modality for cutaneous CM of trunk or extremities.
Subject(s)
Immunosuppressive Agents/therapeutic use , Lasers, Dye/therapeutic use , Port-Wine Stain/drug therapy , Sirolimus/therapeutic use , Administration, Topical , Adult , Combined Modality Therapy , Erythema/etiology , Female , Humans , Immunosuppressive Agents/adverse effects , Lasers, Dye/adverse effects , Low-Level Light Therapy , Male , Middle Aged , Pilot Projects , Port-Wine Stain/radiotherapy , Prospective Studies , Sirolimus/adverse effects , Treatment Outcome , Young AdultABSTRACT
BACKGROUND: Riehl's melanosis presents as a diffuse gray-brown to black hyperpigmentation around face. The treatment of this disease is challenging and quite limited despite patients' excessive psychological stresses. OBJECTIVE: In this prospective pilot study, we evaluated the efficacy and safety for a novel combination therapy based on low-fluence Q-switched 1064 nm Nd:YAG laser, hydroquinone cream and oral tranexamic acid for recalcitrant Riehl's melanosis. METHODS: Totally eight patients with Riehl's melanosis who had failed improvements previously received multiple sessions (10-18 times) of combination treatment regimen. The primary endpoint was clinical score by the physician and the secondary endpoints were clinical score by the patients, instrumental analysis using melanin and erythema values, and histopathological score. RESULTS: Among eight patients, three received "Almost clear" grade, the other five patients received "Marked improvement" grade at final visits. No serious adverse events and post-treatment downtime was observed. Mean Melanin and Erythema Indexes also showed significant decreases compared with baseline. Histopathologic examination confirmed a significantly greater reduction of melanin content in melanophages. CONCLUSION: This combination method can be a viable option for Asian patients having Riehl's melanosis with high risk of post-inflammatory hyperpigmentation, maintaining low-dose laser irradiation.