體內氧化壓力過高是引起心血管疾病的重要危險因子，並與粥狀動脈硬化的形成有關。已知從飲食中攝取較多蔬果可以降低罹患冠狀動脈疾病的危險。本實驗的目的是在探討蔥青水萃取物之抗氧化能力以及其對巨噬細胞內脂質累積之影響。實驗結果顯示蔥青水萃取物在 0.01- 1.0 mg/mL具有劑量依循相關性的捕捉超氧自由基、一氧化氮、鐵離子及抑制黃嘌呤氧化酶活性，並且在0.5- 2.0 mg/mL具有抑制小鼠心臟均質液之體外蛋白硝化反應之能力。另一方面，蔥青水萃取物在 0.5 mg/mL可阻斷脂多醣降低巨噬細胞中清除者受體BⅠ mRNA及蛋白表現及ABCA1 mRNA表現，且蔥青水萃取物主要成分Quercetin (20 M)及Kaempferol (30 M)亦有類似的抑制作用。另外，VLDL及oxLDL降低清除者受體BⅠ蛋白表現，且蔥青水萃取物(0.5 mg/mL), Quercetin (20 M)及Kaempferol (30 M)皆可阻斷VLDL降低巨噬細胞中ABCA1 mRNA表現。此外，蔥青水萃取物造成上述之結果，可能與其活化轉錄因子PPAR ，或是抑制發炎反應有關。最後也發現蔥青水萃取物 (0.5 mg/mL), Quercetin (20 M)、Kaempferol (30 M) 及9-cis Retinoic acid (RA；40 M)可以降低oxLDL增加巨噬細胞內脂質堆積之情形。這些結果顯示蔥青水萃取物具有對抗氧化壓力及預防心血管疾病等有利的影響。 Oxidative stress increasing in vivo is an important risk factor in the coronary heart disease development and correlated with the formation processing of atherosclerosis. It has been reported that consumption of a traditional diet rich in vegetables and fruits obviously decreases the risk of coronary heart disease. The purpose of this study is to explore the antioxidant capacity of aqueous extract of Welsh onion green leaves (WOE) and whether WOE can modulate intracellular lipid accumulation in RAW 264.7 macrophages.The results showed that WOE in 0.01 – 1.0 mg/ml can scavenge superoxide radicals, nitric oxide, ferrous ions and inhibit xanthine oxidase activity in a dose-dependent manner. And WOE in 0.5 – 2.0 mg/ml inhibit protein tyrosine residue nitration in mouse heart homogenate in vitro. On the other hand, WOE at 0.5 mg/ml can block lipopolysaccharide (LPS)-decreased scavenger receptor B1 (SR-B1) and ATP- binding cassette transporter A1 (ABCA1) expression in macrophage RAW 264.7 cells. Quercetin (20 M) and kaempferol (30 M), the major components of WOE, also show the similar inhibitory action on SR-B1 and ABCA1. Furthermore, VLDL and oxLDL decreases SR-BⅠ expression in macrophages. WOE (0.5 mg/ml), Quercetin (20 M) and kaempferol (30 M) block VLDL-decreased ABCA1 expression in macrophages. These results may be contributed by WOE’s direct or indirect actions in PPAR activation or inflammatory inhibition in macrophages. Finally, WOE (0.5 mg/mL), Quercetin (20 M)、Kaempferol (30 M) and 9-cis Retinoic acid (RA；40 M) also decrease oxLDL-induced intracellular lipid accumulation in macrophages. These results implied that WOE might have benefit in protect consumers from oxidative stress and cardiovascular diseases.
