4-phenylpyridine suppresses UVB-induced skin inflammation by targeting c-Src in vitro and in vivo.

Acute or repetitive exposure to ultraviolet (UV) cause disruptions to the skin barrier and subsequent inflammatory skin disease. 4-phenylpyridine (4-PP) is a constituent of Brassica campestris L. ssp. Pekinensis and its effect on skin inflammation and molecular target remain unclear. The purpose of this study is to confirm the anti-inflammatory efficacy of 4-PP on UVB-induced skin inflammation in human keratinocytes HaCaT and mouse skin and validation of its molecular target. 4-PP also attenuated UVB-induced phosphorylation of p38/mitogen-activated protein kinase kinase (MKK) 3/6, c-Jun N-terminal kinase 1/2, MKK 4/7, extracellular-signal-regulated kinase 1/2, mitogen-activated protein kinase 1/2. Additionally, 4-PP inhibited UVB-induced phosphorylation of epidermal growth factor receptor (EGFR) Y1068, Y1045 and 854 residues but not the proto-oncogene tyrosine-protein kinase c-Src. Drug affinity responsive target stability assay revealed that 4-PP directly binds to c-Src and inhibits pronase c-proteolysis. Knockdown of c-Src inhibited UVB-induced COX-2 expression and phosphorylation of MAPKs and EGFR in HaCaT cells. Dorsal treatment of 4-PP prevented UVB (0.5 J/cm2 )-induced skin thickness, phosphorylation of EGFR and COX-2 expression in mouse skin. Our findings suggest that 4-PP can be used as anti-inflammatory agent with an effect of skin inflammation by inhibiting the COX-2 expression via suppressing the c-Src/EGFR/MAPKs signalling pathway.

In Vitro and In Vivo Models for the Development of Hair Growth Materials By Regulating the ß-Catenin Signaling Pathways.

Although hair loss contributes to various social and economic, research methods for material development are currently limited. In this study, we established a research model for developing materials for hair growth through the regulation of ß-catenin. We confirmed that 100 nM tegatrabetan (TG), a ß-catenin inhibitor, decreased the proliferation of human hair follicle dermal papilla cells (HFDPCs) at 72 h. In addition, TG-induced apoptosis suppressed the phosphorylation of GSK-3ß and Akt, translocation of ß-catenin from the cytosol to the nucleus, and the expression of cyclin D1. Interestingly, TG significantly increased the G2/M arrest in HFDPCs. Subcutaneous injection of TG suppressed hair growth and the number of hair follicles in C57BL/6 mice. Moreover, TG inhibited the expression of cyclin D1, ß-catenin, keratin 14, and Ki67. These results suggest that TG-induced inhibition of hair growth can be a promising model for developing new materials for enhancing ß-catenin-mediated hair growth.

Recovery Effects of Nephelium lappaceum var. pallens (Hiern) Leenh. Extract on Testosterone-Induced Inhibition of Hair Growth in C57BL/6 Mice and Human Follicular Dermal Papilla Cells.

Although various hair health medicines have been developed and are used today, additional safe and effective natural hair growth therapies still need to be developed. Nephelium lappaceum var. pallens (Hiern) Leenh. extract (NLE) reportedly exhibits anticancer, antidiabetic, and antioxidant effects, which could be linked to androgenic processes; however, there are no reports of its effects on testosterone (TS)-inhibited hair growth. The present study investigated the effects of NLE on TS-induced inhibition of hair growth in C57BL/6 mice and human follicular dermal papilla cells. Oral administration of NLE restored hair growth that was suppressed following subcutaneous injection of TS more effectively than finasteride, a drug used for treating hair loss. Histological analysis demonstrated that oral NLE administration increased the number and diameter of hair follicles in the dorsal skin of C57BL/6 mice. In addition, western blot and immunofluorescence assays showed that the oral NLE administration restored TS-induced suppression of cyclin D1, proliferating cell nuclear antigen, and loricrin expression in the skin cells of the mice. Finally, TS suppression of cell proliferation in human follicular dermal papilla cells was significantly reversed by NLE pretreatment. The results suggest that NLE is a promising nutraceutical for hair growth because it promotes hair growth in androgenetic alopecia-like models.

The In Vivo and In Vitro Effects of Terminalia bellirica (Gaertn.) Roxb. Fruit Extract on Testosterone-Induced Hair Loss.

Due to the continuous increase in patients with androgenetic alopecia (AGA) and psychological disorders such as depression and anxiety, the demand for hair loss treatment and effective hair growth materials has increased. Terminalia bellirica (Gaertn.) Roxb. (TBE) reportedly exerts anti-inflammatory, hepatoprotective, and antidiabetic effects, among others, but its effects on testosterone (TS)-inhibited hair growth remains unclear. In this study, we evaluated the effects of TBE on TS-induced hair growth regression in human follicle dermal papilla cells (HFDPCs) and C57BL/6 mice. Oral administration of TBE increased TS-induced hair growth retardation. Interestingly, effects were greater when compared with finasteride, a commercial hair loss treatment product. Histological analyses revealed that oral TBE administration increased hair follicles in the dorsal skin of C57BL/6 mice. Additionally, western blotting and immunofluorescence showed that oral TBE administration recovered the TS-induced inhibition of cyclin D1, proliferating cell nuclear antigen (PCNA), and Ki67 expression in vivo. Using in vitro proliferation assays, TBE promoted HFDPC growth, which was suppressed by TS treatment. Thus, TBE may be a promising nutraceutical for hair health as it promoted hair growth in AGA-like in vitro and in vivo models.