Department of Dermatology, West China Hospital, Sichuan University, Chengdu, 610041, China; Laboratory of Dermatology, Clinical Institute of Inflammation and Immunology, Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, Chengdu, 610041, China.
Department of Pharmacology, West China School of Basic Sciences & Forensic Medicine; Animal Research Institute, Sichuan University, Chengdu, 610041, China; Department of Basic Medical Sciences, Sichuan Vocational College of Health and Rehabilitation, Zigong, 643000, China.
J Ethnopharmacol. 2024 Jan 10;318(Pt B):116974. doi: 10.1016/j.jep.2023.116974. Epub 2023 Jul 29.
Dendrobium officinale Kimura & Migo is traditionally used to treat skin diseases, gastrointestinal diseases, and other diseases. Dendrobium officinale polysaccharides (DOP) are the main component of Dendrobium officinale that accounts for its bioactivity, which shows a variety of effects such as moisturizing, antioxidant and anti-fatigue. However, there is no comprehensive study on the effect of DOP on skin photoaging combined with in vitro and in vivo models, and its specific mechanism is still unclear.
Our study aimed to explore the effect and underlying mechanism of DOP on skin photoaging, as well as to improve the stability and transdermal absorption of DOP.
DOP was extracted, purified and structurally characterized. In vitro HaCaT cell photoaging model was used to examine the photoprotection effect of DOP. Cell viability was detected by CCK-8; Intracellular reactive oxygen species were determined by DCFH-DA; DNA damage, cell apoptosis and cell cycle arrest were examined by flow cytocytometry. For autophagy flux detection, the adenovirus loaded with mRFP-GFP-LC3 was introduced into cells. Further, to enhance the stability and absorption of DOP, we designed and prepared the W/O/W type DOP multilayer emulsions (ME) by a two-step emulsification method. The emulsion stability, drug loading and encapsulation rate, DOP stability and DOP transdermal rate were detected. In vivo photoaging animal model was applied to compare the difference of photoaging protection effect between DOP solution and DOP ME. Specifically, skin appearance, histological change, antioxidant system, proinflammatory indicators, matrix metalloproteinases and autophagy level of skin tissues were examined and compared.
The results showed that DOP achieve photoaging protection by inhibiting oxidative stress, alleviating cell cycle arrest and apoptosis, and enhancing autophagy flux in photoaged HaCaT cells. The W/O/W type DOP multilayer emulsion (ME) with high encapsulation rate and strong stability was found to significantly improve the stability and transdermal absorption of DOP. In addition, our results showed that DOP (ME) remarkably improved skin condition of photoaged mice. Specifically, DOP (ME) enhanced the expression of antioxidant enzymes and autophagy and decreased the levels of pro-inflammatory factors and matrix metalloproteinases in the skin of photoaged mice as compared with DOP solution.
In conclusion, DOP was effective in improving skin photoaging, and the DOP multilayer emulsion we designed enhanced the stability and skin absorption of DOP, boosting DOP's protective effect against photoaging.
ETHNOPHARMACOLOGICAL 相关性：铁皮石斛 Kimura 和 Migo 传统上用于治疗皮肤病、胃肠道疾病和其他疾病。铁皮石斛多糖（DOP）是铁皮石斛的主要成分，占其生物活性，表现出多种效果，如保湿、抗氧化和抗疲劳。然而，目前还没有关于 DOP 对皮肤光老化的综合研究，结合体外和体内模型，以及其具体机制仍不清楚。
本研究旨在探讨 DOP 对皮肤光老化的作用及其潜在机制，并提高 DOP 的稳定性和透皮吸收。
提取、纯化和结构表征 DOP。采用体外 HaCaT 细胞光老化模型研究 DOP 的光保护作用。通过 CCK-8 检测细胞活力；通过 DCFH-DA 测定细胞内活性氧；通过流式细胞术检测 DNA 损伤、细胞凋亡和细胞周期阻滞。为了检测自噬流，引入了携带 mRFP-GFP-LC3 的腺病毒。此外，为了提高 DOP 的稳定性和吸收，我们通过两步乳化法设计并制备了 W/O/W 型 DOP 多层乳液（ME）。检测乳液稳定性、载药量和包封率、DOP 稳定性和 DOP 透皮率。应用体内光老化动物模型比较 DOP 溶液和 DOP ME 之间光老化保护效果的差异。具体比较皮肤外观、组织学变化、抗氧化系统、促炎指标、基质金属蛋白酶和皮肤组织自噬水平。
结果表明，DOP 通过抑制氧化应激、减轻细胞周期阻滞和凋亡、增强光老化 HaCaT 细胞中的自噬流来实现光老化保护。具有高包封率和强稳定性的 W/O/W 型 DOP 多层乳液（ME）可显著提高 DOP 的稳定性和透皮吸收。此外，我们的结果表明，DOP（ME）显著改善了光老化小鼠的皮肤状况。具体而言，与 DOP 溶液相比，DOP（ME）增强了抗氧化酶和自噬的表达，降低了光老化小鼠皮肤中促炎因子和基质金属蛋白酶的水平。
总之，DOP 对改善皮肤光老化有效，我们设计的 DOP 多层乳液增强了 DOP 的稳定性和皮肤吸收，增强了 DOP 对光老化的保护作用。
