紅藜萃出物對TNF-α誘發人類血管內皮細胞發炎之保護作用及調控機制

血管內皮功能障礙是眾多疾病的共同病理基礎，為啟動動脈粥狀硬化(Atherosclerosis)的第一步驟，亦是發展成心血管疾病(Cardiovascular disease, CVD)重要指標。腫瘤壞死因子-α (Tumor necrosis factor-α, TNF-α)為促發炎細胞激素，會誘發活性氧(Reactive oxygen species, ROS)產生，進而導致內皮功能障礙。台灣藜又名紅藜(Chenopodium formosanum, CF)，為莧科藜亞科藜屬植物。紅藜萃出物(Chenopodium formosanum extract, CFE)含有黃酮類化合物，具有抗氧化、抗發炎、抗脂肪生成等作用。然而截至目前，紅藜對保護血管內皮功能相關機制尚未釐清。本研究以EA.hy926人類血管內皮細胞探討CFE對TNF-α誘發血管內皮細胞黏附、發炎、內皮間質轉化(Endothelial-to-mesenchymal transition, EndMT)及氧化壓力之影響。結果顯示，以10 ng/mL TNF-α處理細胞，雖不影響細胞存活率，但顯著增加活性氧(Reactive oxygen species, ROS)生成，上調磷酸化c-Jun N末端激酶(c-Jun N-terminal kinase, JNK)、細胞外訊號調節激酶(Extracellular signal-regulated kinase, ERK)、p38絲裂原蛋白激活酶(p38 mitogen-activated protein kinase, p38 MAPK)、蛋白激酶B (Protein kinase B, PKB/Akt)、轉錄訊息傳遞及活化蛋白(Signal transducer and activator of transcription 3, STAT3)，促使核因子-κB (Nuclear factor kappa-B, NF-κB)易位至細胞核內，進而增加血管细胞黏附分子-1 (Vascular cell adhesion protein-1, VCAM-1)、細胞間附著分子-1 (Intercellular adhesion molecule-1, ICAM-1)、介白素-1β (Interleukin-1 beta, IL-1β)、介白素-6 (Interleukin-6, IL-6)和EndMT相關蛋白如波形蛋白(Vimentin)之表現，同時減少血管內皮鈣黏蛋白(VE-cadherin)之表現。預處理150 µg/mL CFE則增加抗氧化酵素如超氧化物歧化酶1 (Superoxide dismutase 1, SOD1)、超氧化物歧化酶2 (Superoxide dismutase 2, SOD2)、穀胱甘肽還原酶(Glutathione reductase, GR)、過氧化氫酶(Catalase)、血基質氧化酶(Heme oxygenase-1, HO-1)之表現，同時抑制TNF-α所誘發ROS生成、p-JNK、p-ERK、p-Akt、VCAM-1、ICAM-1、IL-1β、IL-6、Vimentin和VE-cadherin之表現。綜合上述結果，CFE可透過上調抗氧化酵素抑制TNF-α所誘發EA.hy926細胞ROS生成及ERK/NF-κB、JNK/NF-κB、Akt/ NF-κB及STAT3所誘發的細胞黏附、發炎、EndMT，達到改善血管內皮功能障礙。

Endothelial dysfunction is the common pathological basis for various diseases, serving as the first step in the initiation of atherosclerosis and an important indicator of the future development of Cardiovascular disease (CVD). Tumor necrosis factor-α (TNF-α), a proinflammatory cytokine, has been shown to induce the production of reactive oxygen species and lead to endothelial dysfunction. Chenopodium formosanum ,also known as Djulis, is an amaranthaceae chenopodioideae chenopodium plant. The extract of Chenopodium formosanum (CFE) contains several flavonoid compounds exerting antioxidative, anti-inflammatory, and antiadipogenicproperties. However, the mechanism of CFE in protecting the endothelial function has not been clarified. In this study, EA.hy926 human vascular endothelial cells were used to investigate the effect of CFE on TNF-α-induced inflammation, adhesion, endothelial-to-mesenchymal transition (EndMT), and oxidative stress. The results showed that treatment with 10 ng/mL TNF-α did not affect cell viability, but significantly increased reactive oxygen species (ROS) production, and the phosphorylation of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), p38 mitogen-activated protein kinases (p38), protein kinase B (PKB/Akt) and signal transducer and activator of transcription 3 (STAT3). Moreover, the nuclear translocation of nuclear factor kappa-B (NF-κB) and the protein level of vascular cell adhesion protein-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), interleukin-1 beta (IL-1β), interleukin-6 (IL-6) as well as EndMT-relate protein such as vimentin, but VE-cadherin were increased by TNF-α. Pretreatment with 150 µg/mL CFE significantly increased superoxide dismutase 1 (SOD1), superoxide dismutase 2 (SOD2), glutathione reductase (GR), catalase as well as heme oxygenase-1 (HO-1), and decreased TNF-α mediated ROS production, p-ERK, p-Akt, p-JNK, VCAM-1, ICAM-1, IL-1β, IL-6, vimentin, and VE-cadherin. Taken together, CFE can inhibit TNF-α induced ROS production, ERK/NF-κB, JNK/NF-κB, Akt/NF-κB as well as STAT3, and decrease inflammation, adhesion, EndMT by upregulating antioxidant enzymes in EA.hy926 cell to improving vascular endothelial dysfunction.