Photoprotective Effects of Dendrobium nobile Lindl. Polysaccharides against UVB-Induced Oxidative Stress and Apoptosis in HaCaT Cells.

Acute ultraviolet (UV)-B radiation is the major external factor causing photodamage. In this study, we aimed to determine the effects of Dendrobium nobile Lindl. polysaccharides (DNPs) on photodamage in HaCaT keratinocytes after UVB irradiation and the underlying mechanisms. We found that DNPs significantly attenuated the decline in the viability and proliferation of HaCaT cells after UVB irradiation. Moreover, DNPs scavenged reactive oxygen species (ROS), improved the activities of endogenous antioxidant enzymes, including superoxide dismutase, catalase, and glutathione peroxidase, and reduced the levels of malondialdehyde, while partially attenuating cell cycle arrest, suggesting their antioxidant and anti-apoptotic properties. The mitogen-activated protein kinase (MAPK) pathway was found to be important for the attenuation of UVB-induced photodamage in the HaCaT cells. Furthermore, DNPs exerted cytoprotective effects by downregulating UVB-induced ROS-mediated phosphorylation of MAPKs, including p38, c-Jun N-terminal kinase, and extracellular signal-regulated kinase, and by inhibiting p53 expression as well as the apoptotic cascade response. Therefore, DNPs ameliorated UVB-induced oxidative damage and apoptosis in HaCaT cells via the regulation of MAPKs. Our findings thus highlight the Dendrobium nobile Lindl polysaccharides as promising therapeutic candidates for UVB-induced photodamage.

Controlling Hair Loss by Regulating Apoptosis in Hair Follicles: A Comprehensive Overview.

Apoptosis is a physiological process that occurs in all cell types of the human body, and it profoundly changes the fate of hair by affecting hair follicle cells. This review outlines the cellular changes, intrinsic biochemical characteristics, and mechanisms underlying apoptosis and summarizes the hair follicle life cycle, including development, cycle stages, and corresponding cellular changes. Finally, the relationship between apoptosis and the hair cycle is discussed and the significance of apoptosis in hair loss conditions and drug treatments is highlighted. Apoptosis induces cellular changes and exhibits distinctive properties through intricate signaling pathways. Hair follicles undergo cyclic periods of growth, regression, and dormancy. Apoptosis is closely correlated with the regression phase by triggering hair follicle cell death and shedding. Regulation of apoptosis in hair follicles plays an essential role in hair loss due to maladies and drug treatments. Mitigating apoptosis can enhance hair growth and minimize hair loss. A comprehensive understanding of the correlation between apoptosis and the hair cycle can facilitate the development of novel treatments to prevent hair loss and stimulate hair regeneration.

Dendrobium nobile Lindl Polysaccharides Attenuate UVB-induced Photodamage by Regulating Oxidative Stress, Inflammation and MMPs Expression in Mice Model.

Acute ultraviolet B (UVB) irradiation predominantly leads to various skin disorders caused by photodamage. The major causes of UVB-induced photodamage include oxidative stress, inflammatory infiltration and collagen degradation. The aim of the study was to elucidate whether DNP had protective effect on the skin of KM mice when exposed to UVB irradiation. The DNP protective properties to skin appearance and histopathological alterations in KM mice were evaluated by hematoxylin-eosin staining, toluidine blue staining, Gomori staining and Masson's trichrome staining and mast cell staining. In this study, DNP pretreatment promoted the activities of antioxidant enzymes, including superoxide dismutase, catalase and glutathione peroxidase, while decreased malondialdehyde level in UVB-irradiated skin, along with downregulation of proteins expression of matrix metalloproteinases and reduction in the level of the proinflammatory cytokines. Based on these findings, we demonstrated that DNP displayed strong ameliorative effects on UVB-induced acute photodamage for the first time, indicating that it would be a promoting ingredient candidate that could be used in antiphotodamage.

Stimulation of hair growth by Tianma Gouteng decoction: Identifying mechanisms based on chemical analysis, systems biology approach, and experimental evaluation.

Hair serves important physiological functions, including temperature regulation and scalp protection. However, excessive shedding not only impacts these functions but can also significantly affect mental health and quality of life. Tianma Gouteng decoction (TGD) is a traditional Chinese medicine used for the treatment of various conditions, including hair loss. However, the associated mechanism underlying its anti-alopecia effect remains unknown. Therefore, this study aims to elucidate these mechanisms by employing systematic biology approaches, as well as in vitro and in vivo experimental validation. The chemical constituents of Tianma Gouteng decoction were identified using UHPLC-MS/MS, from which 39 potential bioactive components were screened, while an additional 131 putative Tianma Gouteng decoction beneficial components were extracted from the Traditional Chinese Medicine Database and Analysis Platform (TCMSP) database. We then applied a dual-dimensional network pharmacology approach to analyze the data, followed by validation studies combining molecular docking techniques with in vivo and in vitro experiments. From the 39 bioactive components, including quercetin, luteolin, fisetin, wogonin, oroxylin A, boldine, tetrahydroalstonine, and galangin A, 782 corresponding targets were identified. In particular, GSK3ß and ß-catenin exhibited strong binding activity with the bioactive compounds. Hence, construction of a bioactive component-target network revealed that the mechanism underlying the anti-alopecia mechanism of Tianma Gouteng decoction primarily involved the Wnt/ß-catenin signaling pathway. Moreover, C57BL/6J mice exhibited measurable improvements in hair follicle regeneration following treatment with Tianma Gouteng decoction. Additionally, ß-catenin and p-GSK3ß levels were upregulated, while GSK3ß was downregulated in Tianma Gouteng decoction-treated animals and dermal papilla cells compared to control group. These in vivo and in vitro outcomes validated the targets and pathways predicted in the network pharmacology analysis of Tianma Gouteng decoction. This study provides a systematic analysis approach to identify the underlying anti-alopecia mechanisms of Tianma Gouteng decoction, further providing theoretical support for clinical assessment of Tianma Gouteng decoction.