Backgrounds. Polysaccharides of Dendrobium candidum (PDC) showed a strong antioxidant effect on islet cells while the effects of PDC on human umbilical vein endothelial cells (HUVECs) under the high glucose condition remain unclear. Material and Method. HUVECs were incubated with high glucose (33.3 mmol/L) for 48 hours to induce injury, and cells were treated with PDC (100, 200, and 400 μg/mL) for 48 hours. The tetrazolium blue colorimetric (MTT) assay was used to detect cell proliferation, superoxide dismutase (SOD), and nitric oxide (NO) content in cell supernatants. Flow cytometry was used to detect reactive oxygen species (ROS) and calcium levels. Results. (1) Compared with the control group, the proliferation of HUVECs cells in the high glucose (33.3 mmol/L) group decreased (). The intracellular calcium ion concentration and the intracellular ROS level increased ( and ). SOD activity and the level of NO in the culture medium were reduced (P <0.05). (2) Compared with the control group, PDC (50, 100, 200, 400, and 800 μg/mL) did not significantly affect the cell proliferation of HUVECs (). (3) Compared with the high glucose group, the HUVEC cell viability of the high glucose + PDC (100, 200, and 400 μg/mL) group increased while the intracellular calcium ion concentration decreased in a concentration-dependent manner (). Intracellular ROS levels were reduced, while SOD activity and the level of NO in culture fluids increased (). Conclusion. PDC can promote the proliferation of HUVECs in the high glucose environment by reducing oxidative stress injury of HUVECs induced by high glucose.

中文翻译：

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石斛多糖对高糖环境下人脐静脉内皮细胞增殖及氧化应激的调控

背景。铁皮石斛多糖（PDC）对胰岛细胞具有很强的抗氧化作用，而PDC在高糖条件下对人脐静脉内皮细胞（HUVECs）的影响尚不清楚。材料和方法。HUVECs与高糖（33.3 mmol/L）孵育48小时以诱导损伤，细胞用PDC（100、200和400μg  / mL）处理48小时。四唑蓝比色法 (MTT) 用于检测细胞上清液中的细胞增殖、超氧化物歧化酶 (SOD) 和一氧化氮 (NO) 含量。流式细胞仪用于检测活性氧（ROS）和钙水平。结果. (1)与对照组相比，高糖(33.3 mmol/L)组HUVECs细胞增殖减少(）。细胞内钙离子浓度和细胞内活性氧水平升高（ 和 ）。培养基中SOD活性和NO水平降低（ P  <0.05）。（2）与对照组相比，PDC（50、100、200、400、800  μ g/mL）对HUVECs的细胞增殖没有显着影响（）。（3）与高糖组相比，高糖+PDC（100、200、400μg /mL）组HUVEC细胞活力增加，细胞内钙离子浓度呈浓度依赖性降低（）。细胞内 ROS 水平降低，而培养液中 SOD 活性和 NO 水平升高。）。 结论。PDC通过降低高糖诱导的HUVECs氧化应激损伤，促进HUVECs在高糖环境中的增殖。