槲皮素和染料木黃酮調控脂多醣誘發C2C12肌肉細胞發炎反應之功效

The effects of quercetin and genistein on lipopolysaccharide-induced inflammatory responses in C2C12 skeletal muscle cells

施采瑩(Cai-Ying Shih)

指導教授 ： 劉德中

中山醫學大學/健康管理學院/營養學系碩士班/碩士(2018年)

摘要

發炎反應雖然是身體抵抗外來侵略時防禦能力之一，但是慢性發炎反應與許多疾病的發生及進展有密切關係。研究證實，巨噬細胞RAW264.7處理脂多醣體lipopolysaccharide (LPS)誘發發炎反應，是經由活化Mitogen-activated protein kinase (MAPKs)訊息傳遞與Nuclear factor kappa B (NF-κB)轉錄活性，增加促發炎媒介物及相關酵素如: inducible nitric oxide synthase，cyclooxygenase-2，interleukin-6 (IL-6)，interleukin-1β (IL-1β)和tumor necrosis factor-α (TNF-α)生成。許多有保健功效的植物素例如: quercetin和genistein可經由抑制MAPKs-NF-κB路徑，減少發炎反應。發現除了免疫細胞外，身體其他組織例如：脂肪及肌肉組織受到LPS刺激時，亦會增加促發炎細胞激素例如: TNF-α、IL-1β和IL-6生成，使代謝改變，造成血脂升高、肝臟內糖質新生作用增加、蛋白質分解和胰島素敏感性降低。Quercetin和genistein 普遍存在於人類飲食中，通常來自於水果、蔬菜、大豆製品中，有抗癌、抗發炎和抗氧化等功效。本實驗利用LPS誘發C2C12肌肉細胞發炎反應之模式，評估quercetin和genistein改善C2C12肌肉細胞發炎之功效。根據3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay結果顯示共同處理LPS (100 ng/ml)和quercetin (5或10 μM)及genistein (5 μM)18小時，並不會造成細胞毒性。處理quercetin和genistein可降低LPS誘發IL-6、IL-1β、TNF-α mRNA表現。此外，預處理quercetin和genistein會使LPS誘發extracellular-regulated protein kinase 2、inhibitor-kappa Bα 與p65磷酸化受阻。除此之外，quercetin在單獨處理或與LPS共同處理下，可顯著增加抗氧化酵素catalase、heme oxygenase-1、quinone oxidoreductase 1蛋白質表現。綜合以上研究結果可知quercetin和genistein具有改善LPS誘發C2C12肌肉細胞的發炎反應及增加細胞內抗氧化酵素的功效。

關鍵字

C2C12肌肉細胞 ； 槲皮素 ； 染料木黃酮 ； 脂多醣體 ； 發炎反應

並列摘要

Inflammation response acts as a defense against foreign aggression, but chronic inflammation plays a close relationship in pathogenesis and progression of many diseases. It was reported that exposure of RAW 264.7 macrophages with lipopolysaccharide (LPS) could induce inflammation via activation of mitogen-activated protein kinase (MAPKs) signal transduction and nuclear factor kappa B (NF-κB) transcriptional activity to enhance expression of the pro-inflammatory factors and enzymes such as inducible nitric oxide synthase, cyclooxygenase-2, interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). Many Phytochemicals such as quercetin and genistein via inhibiting MAPKs-NF-κB pathway, attenuate the LPS-induced inflammation. In addition to immunocytes, other body tissues like adipose and muscle tissues treated with LPS could produce inflammatory cytokines such as TNF-α, IL-1β and IL-6 which are associated with metabolic changes, elevation of blood lipids, gluconeogenesis, protein catabolism and insulin resistance. Quercetin and genistein occur ubiquitously in the human diet including fruits, vegetables and soybean and its products. It is reported that quercetin and genistein has healthy beneficial properties including anti-carcinogenesis, anti-inflammation and anti-oxidation. The aim of current study is to investigate the effects of quercetin and genistein on LPS induced inflammation in C2C12 skeletal muscle cells. Treated with LPS and quercetin (5 μM or 10 μM) or genistein (5 μM) for 18 hrs has no cytotoxic effect on C2C12 skeletal muscle cells determined by 3-(4,5-dimethylthiazol-2-yl)- 2,5- diphenyltetrazolium bromide assay. Quercetin and genistein significantly attenuated the LPS-induced mRNA expression of pre-inflammatory mediators, including IL-6、IL-1β、TNF-α. Additionally, quercetin and genistein inhibited LPS induced phosphorylation of extracellular-regulated protein kinase 2、inhibitor-kappa Bα and p65. Furthermore, treated with quercetin alone or combined with LPS significantly enhanced catalase, heme oxygenase-1 and quinone oxidoreductase 1 protein expression. In summary, quercetin and genistein decrease inflammation and increase antioxidant protein expression of in C2C12 skeletal muscle cells treated with LPS.

並列關鍵字

C2C12 skeletal muscle cells ； quercetin ； genistein ； lipopolysaccharide ； Inflammation

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