Undariopsis peterseniana Promotes Hair Growth by the Activation of Wnt/β-Catenin and ERK Pathways

Abstract

In this study, we investigated the effect and mechanism of Undariopsis peterseniana, an edible brown alga, on hair growth. The treatment of vibrissa follicles with U. peterseniana extract ex vivo for 21 days significantly increased the hair-fiber lengths. The U. peterseniana extract also significantly accelerated anagen initiation in vivo. Moreover, we found that U. peterseniana extract was able to open the K_ATP channel, which may contribute to increased hair growth. The U. peterseniana extract decreased 5α-reductase activity and markedly increased the proliferation of dermal papilla cells, a central regulator of the hair cycle. The U. peterseniana extract increased the levels of cell cycle proteins, such as Cyclin D1, phospho(ser780)-pRB, Cyclin E, phospho-CDK2, and CDK2. The U. peterseniana extract also increased the phosphorylation of ERK and the levels of Wnt/β-catenin signaling proteins such as glycogen synthase kinase-3β (GSK-3β) and β-catenin. These results suggested that the U. peterseniana extract had the potential to influence hair growth by dermal papilla cells proliferation through the activation of the Wnt/β-catenin and ERK pathways. We isolated a principal of the U. peterseniana extract, which was subsequently identified as apo-9'-fucoxanthinone, a trichogenic compound. The results suggested that U. peterseniana extract may have a pivotal role in the treatment of alopecia.

Keywords: 5α-reductase; KATP channel; Undariopsis peterseniana; Wnt/β-catenin; apo-9′-fucoxanthinone; dermal papilla cell; hair growth.

Figure 1

Undariopsis peterseniana extract increases hair growth in ex vivo organ culture. Rat vibrissa follicles were cultured with the indicated concentrations of U. peterseniana extract or minoxidil for 21 days. (A) The time course change of hair-fiber length was measured by DP controller software. Each dot indicates an independent follicle length. Horizontal lines showed mean ± SE. * p < 0.05 compared with the control; (B) The change in length of vibrissa follicles at 21 days was compared to the mean length of control follicles. The mean length of control follicles was set at 100% and each dot indicates an independent follicle length (%). Horizontal lines showed the mean ± SE. * p < 0.05 compared with the control.

Figure 2

U. peterseniana extract accelerates the progression of anagen phase in vivo. U. peterseniana extract (0.1, 1, and 10 μg/mL) was topically treated to C57BL/6 mice dorsal skin for 34 days. (A) The change in skin color was observed after photographing at the indicated times after depilation; (B) Quantification of anagen induction by dotmatrix planimetry. On day 34, the area of interest in back skin was marked in transparency film. Acceleration to the anagen phase was expressed as a percentage of the area of the black skin compare to the total skin area. Data are presented as the mean ± SE (n = 8). * p < 0.05, *** p < 0.001 compared with the control.

Figure 3

U. peterseniana extract inhibits 5α-reductase activity. 5α-Reductase activity was measured by liquid scintillation counting using [1,2,6,7-³H] testosterone. The reaction mixtures were incubated with the indicated concentrations of U. peterseniana extract or finasteride in the presence of crude extract of rat prostate. The conversion rate of testosterone (T) to dihydrotestosterone (DHT) was calculated by the equation: [DHT/(T + DHT)] × 100. The inhibition rate of 5α-reductase activity (%) was estimated as a percentage of the reduction in conversion rate compared with the control. The inhibition rate of the control group was considered 0% (not shown). * p < 0.05, **p < 0.01, *** p < 0.001 compared with the control. Horizontal lines show the mean ± SD. Finasteride was used as reference material to evaluate the inhibition of 5α-reductase activity.

Figure 4

Effect of U. peterseniana extract on the proliferation of NIH3T3 fibroblast via the opening of K_ATP channel. The proliferation of NIH3T3 fibroblasts by the opening of K_ATP channel was measured by MTT assay and tetraethylammonium (TEA) was used as a K_ATP channel blocker. NIH3T3 fibroblasts were pretreated with or without 2 mM TEA, and treated with various concentrations of U. peterseniana extract for 4 days. The proliferation of NIH3T3 fibroblasts was evaluated compared with the 2% BCS control. Each dot indicates an independent experiment and horizontal lines show the mean ± SD. Indicated concentration of minoxidil and TEA were used as reference materials to evaluate cell proliferation by K_ATP channel. ** p < 0.01, *** p < 0.001 compared with the control; ^### p < 0.001 compared with the TEA-treated group.

Figure 5

U. peterseniana extract increases the proliferation of dermal papilla cells as well as the levels of different proteins (cell cycle proteins, Wnt/β-catenin, and phospho-ERK) in dermal papilla cells. (A) The dermal papilla cells were stimulated with U. peterseniana extract and minoxidil, indicated concentrations for 96 h. The MTT assay was used to assess the proliferation of dermal papilla cells. Each dot indicates an independent experiment and horizontal lines showed the mean ± SD. * p < 0.05, **p < 0.01, *** p < 0.001 compared with the control; (B–D) The dermal papilla cells (1.0 × 10⁶ cells) were stimulated U. peterseniana extract and minoxidil, indicated concentrations for 24 h. The whole cell lysate from dermal papilla cells were subjected to immunoblotting with indicated antibodies. * p < 0.05 compared with the control.

Figure 5

U. peterseniana extract increases the proliferation of dermal papilla cells as well as the levels of different proteins (cell cycle proteins, Wnt/β-catenin, and phospho-ERK) in dermal papilla cells. (A) The dermal papilla cells were stimulated with U. peterseniana extract and minoxidil, indicated concentrations for 96 h. The MTT assay was used to assess the proliferation of dermal papilla cells. Each dot indicates an independent experiment and horizontal lines showed the mean ± SD. * p < 0.05, **p < 0.01, *** p < 0.001 compared with the control; (B–D) The dermal papilla cells (1.0 × 10⁶ cells) were stimulated U. peterseniana extract and minoxidil, indicated concentrations for 24 h. The whole cell lysate from dermal papilla cells were subjected to immunoblotting with indicated antibodies. * p < 0.05 compared with the control.

Figure 6

Structure of apo-9′-fucoxanthinone isolated from U. peterseniana.