title: Herbal Extracts Induce Dermal Papilla Cell Proliferation of Human Hair Follicles.
abstract: BACKGROUND
  The number of people suffering from balding or hair thinning is increasing, despite the advances in various medical therapies. Therefore, it is highly important to develop new therapies to inhibit balding and increase hair proliferation.
  
  
  OBJECTIVE
  We investigated the effects of herbal extracts commonly used for improving balding in traditional medicine to identify potential agents for hair proliferation.
  
  
  METHODS
  The expression levels of 5α-reductase isoforms (type I and II) were analyzed using quantitative real-time reverse transcription polymerase chain reaction in the human follicular dermal papilla cells (DPCs). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenylteterazolium bromide and bromodeoxyuridine tests were used to evaluate the cell proliferation effect of herbal extracts in DPCs. The expression levels of extracellular signal-regulated kinase (ERK), Akt, cyclin D1, cyclin-dependent kinase 4 (Cdk4), B-cell lymphoma (Bcl-2) and Bcl-2-associated X protein (Bax) were measured using western blot analysis.
  
  
  RESULTS
  The 5α-reductase isoform mRNAs and proteins were detected in the cultured DPCs, and the expression level of 5α-R2 in DPCs in the presence of the herbal extracts was gradually decreased. Herbal extracts were found to significantly increase the proliferation of human DPCs at concentrations ranging from 1.5% to 4.5%. These results show that the herbal extracts tested affected the protein expressions of ERK, Akt, cyclin D1, Cdk4, Bcl-2, and Bax in DPCs.
  
  
  CONCLUSIONS
  These results suggest that herbal extracts exert positive effects on hair proliferation via ERK, Akt, cyclin D1, and Cdk4 signaling in DPCs; they also suggest that herbal extracts could be a great alternative therapy for increasing hair proliferation.
authors.affiliation: Food and Drug Control Laboratory and Research Center, Tehran, Iran.
authors.forename: Hosein
authors.initials: H
authors.lastname: Rastegar
authors.affiliation: Islamic Azad University, Pharmaceutical Sciences Branch, Tehran, Iran.
authors.forename: Hamidreza Ahmadi
authors.initials: HA
authors.lastname: Ashtiani
authors.affiliation: Department of Clinical Biochemistry, School of Pharmacy and Isfahan Pharmaceutical Sciences Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Aghaei
authors.affiliation: Laser Application in Medical Sciences Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Behrooz
authors.initials: B
authors.lastname: Barikbin
authors.affiliation: Tehran University of Medical Science, Razi Hospital, Tehran, Iran.
authors.forename: Amirohushang
authors.initials: A
authors.lastname: Ehsani
keywords: Dermal papilla cell; Hair follicle; Herbal extracts; Proliferation