蕃茄汁抗氧化成分對發炎反應與相關基因表達之體內評估

In vivo evaluation of inflammatory responses and gene expression to the antioxidant components of tomato juice

臧一凡(Yi-Fan Tsang)

指導教授 ： 蒙美津 ； 邱駿紘

亞洲大學/健康學院/生物科技學系碩士班/碩士(2006年)

摘要

蕃茄是蕃茄紅素的最佳來源，其長期以來即被認為是具有健康效益的食物，而蕃茄產品調控自由基傷害的抗氧化能力是最常被引用來解釋這些正面效益的機制。
研究顯示，蕃茄內的主要活性成分 (如:蕃茄紅素) 可能會影響免疫方面功能的表現。因此本研究主要以動物模式來探討冷凍乾燥蕃茄汁對於內毒素誘發的發炎反應及相關基因表達的影響。
蕃茄汁在冷凍乾燥後，添加至調整過的 AIN-93G 飼料中。以雄性 SD 大鼠為實驗動物，隨機分為四組，分別為:餵食控制飲食組 (C)，餵食控制飲食＋注射脂多醣組 (C＋L)，餵食乾燥蕃茄汁組 (DTJ)，及餵食乾燥蕃茄汁＋注射脂多醣組 (DTJ＋L)。經過四週的實驗飲食飼養後， C＋L 及 DTJ＋L組的大鼠分別在犧牲的四小時前及二十四小時前，注射脂多醣 (10 mg/kg b.w.) 至其腹腔中，以誘導發炎反應。
分析結果顯示，以冷凍乾燥蕃茄汁前處理的動物藉由降低轉胺酶濃度以保護肝臟免於損傷。在單獨給予脂多醣的大鼠組別中，則可發現其一氧化氮、細胞激素及脂質過氧化產物 (丙二醛) 都會升高。而在 DTJ＋L 組中的冷凍乾燥蕃茄汁可明顯抵消血清中這些指標的濃度，也因此可知冷凍乾燥蕃茄汁具有抗發炎及抗脂質過氧化的能力。
用以清除超氧陰離子的 SOD 之活性在各組間並無明顯的改變。而組織中Catalase 及 GSH-Px 的活性則在以冷凍乾燥蕃茄汁前處理的組別中明顯地降低。脂多醣誘發 IL-6 及 iNOS 的基因表現，因而導致 IL-6 及 NO 的大量生成。而在 DTJ+L 組中， IL-6 及 NO 生成量的減少與 iNOS 蛋白質，以及 iNOS 與 IL-6 mRNA 表現的下降是一致的。
在脂多醣單獨處理後，MnSOD 的蛋白質量增加，而 Catalase 及 GSH-Px 的蛋白質則沒有差異。補充冷凍乾燥蕃茄汁則阻止脂多醣所誘發之 MnSOD 的轉譯作用。在脂多醣注射組中可觀察到 MnSOD 及 Catalase 的 mRNA 下降，GSH-Px 的 mRNA 增多,而補充冷凍乾燥蕃茄汁則有相反的改變。
综合上述結果可知，在飼料中補充冷凍乾燥蕃茄汁四星期後，可預防因脂多醣引起的肝損傷。而冷凍乾燥蕃茄汁的這些正面功效可能與其抑制 iNOS 及 IL-6 的生成及其一般抗氧化能力有關。

關鍵字

蕃茄 ； 蕃茄紅素 ； 脂多醣 ； 發炎反應 ； 抗氧化能力

並列摘要

Tomatoes, the best source of lycopene, have been recognized to be beneficial to human health. The most often cited mechanism underlying these observations is the antioxidant potential for tomato and its products to modulate radical-mediated oxidative damage.
Studies showed that the active ingredients such as lycopene in tomato may modulate the immune function. Accordingly, we analyzed the effect of freeze dried tomato juice on the inflammation responses and the gene expressions against endotoxin-induced damages in animal model.
Tomato juices were freeze dried and supplemented in modified AIN-93G diet. Male Sprague-Dawley rats were divided into four groups including control diet (C), control diet plus LPS (C + L), dried tomato juice diet (DTJ) and dried tomato juice diet plus LPS (DTJ + L) groups. Following four weeks of dietary intervention, inflammation was induced at 4h and 24h before sacrifice by peritoneal injection of LPS (10 mg/Kg b.w.) in C + L and DTJ + L groups.
The results indicate that the pretreatment with freeze dried tomato juice protected the liver from damage by reducing the transaminase levels. Elevated levels of NO, cytokines and lipid peroxidation product, MDA, were observed in only LPS administered rats. Freeze dried tomato juice obviously counteracted the increases of these parameters in sera of DTJ＋L rats which suggested anti-inflammatory and anti-lipid peroxidation effects of freeze dried tomato juice.
The activity of SOD, which scavenges superoxide anion, was not significantly changed among all the groups. Pretreatment with freeze dried tomato juice significantly decreased the levels of catalase and GSH-Px activities in tissue. LPS administration leads to IL-6 and NO overproduction after IL-6 and iNOS genes induction. The decreases in quantity of the IL-6 and NO products were accompanied by the decreases in the iNOS protein as well as iNOS and IL-6 mRNA levels in the pretreatment of freeze dried tomato juice followed by LPS-induced animals.
MnSOD protein level increased after LPS injection, whereas the levels of CAT and GSH-Px protein remained consistently. Pretreatment with freeze dried tomato juice blocked the LPS-induced MnSOD translation. We reported a decline in the mRNA expression of MnSOD and CAT; on the other hand, GSH-Px mRNA expression was raised in rats with LPS. Supplementation with freeze dried tomato juice could reverse these alterations.
In conclusion, our present study implicates that the prior administration of freeze dried tomato juice along with feed for 4 weeks prevents the LPS-induced hepatic damage. The positive effects of freeze dried tomato juice may be explained by their capacity to inhibit iNOS and IL-6 induction, as well as by their general antioxidative properties.

並列關鍵字

Tomato ； Lycopene ； Lipopolysaccharide ； Inflammation ； Antioxidant potential

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