Dietary cucurbitacin E reduces high-strength altitude training induced oxidative stress, inflammation and immunosuppression

Abstract Professional athletes conduct high-intensitive hypoxic training often accompanied by the increase of many inflammatory-related cytokines and immunosuppression. Cucurbitacin E (CucE), as a triterpenoid isolated from Cucurbitaceae plants, exert potential anti-cancer and anti-inflammatory. However, it is unknown whether that the CucE could be used as dietary supplement for athletes to improve inflammatory response and immunosuppression. In this study, we established the simulative hypoxic training rat and monkey models and evaluated the effects of CucE on immune- and inflammation-related factors. Obvious improvement on pro-inflammatory factors and pro-lymphocyte proliferation activities were showed in CucE treated rats compared with the control. Further supplement of CucE in professional meals for cynomolgus monkeys with 4-weeks high-intensitive hypoxic training also exert effects on altitude-induced oxidative stress, inflammation and immunologic function. Furtherly, we explored the underlying mechanism of CucE in human Jurkat T cells and results showed that CucE may exhibit immunosuppressive effect by attenuating critical cytokine expression through down-regulating the NF-κB signaling pathway. In conclusion, CucE is expected to be a potential dietary supplement for athletes to ameliorate the inflammation and immunosuppression caused by high-intensitive exercise.

摘要
专业运动员常进行高强度低氧训练，该训练过程常伴随多种炎症相关细胞因子水平升高以及免疫抑制现象。葫芦素E（Cucurbitacin E, CucE）是从葫芦科植物中分离得到的三萜类化合物，具有潜在的抗癌与抗炎活性。然而目前尚不清楚葫芦素E是否可作为运动员的膳食补充剂，以改善其因高强度低氧训练引发的炎症反应与免疫抑制状态。
本研究构建了模拟高强度低氧训练的大鼠与食蟹猴模型，评估了葫芦素E对免疫与炎症相关因子的影响。结果显示，与对照组相比，经葫芦素E干预的大鼠体内促炎因子水平与淋巴细胞增殖活性均得到显著改善。在接受4周高强度低氧训练的食蟹猴的定制膳食中额外添加葫芦素E，同样可改善高原诱导的氧化应激、炎症反应与免疫功能。
进一步，本研究在人类Jurkat T细胞中探究了葫芦素E的潜在作用机制，结果显示，葫芦素E可能通过下调核因子κB（NF-κB）信号通路，抑制关键细胞因子的表达，从而改善免疫抑制状态。
综上，葫芦素E有望成为一款潜在的膳食补充剂，用于改善运动员因高强度运动引发的炎症反应与免疫抑制状态。