巴拉刈 (Paraquat) 為一農業上廣泛使用且具肺毒性之除草劑。巴拉刈毒性機制為在生物體內產生大量的˙O2-(Superoxide anion)、活性氧物種(reactive oxygen species)，攻擊細胞膜產生脂質過氧化產物(lipid peroxidation)，造成細胞膜傷害，進一步導致細胞破壞死亡。巴拉刈中毒死亡的病因是藉由肺部的 發炎反應，進一步造成肺纖維化，產生肺衰竭而致命。NAC　(N-acetylcysteine)為GSH(Glutathione)的前驅物，亦具有直接清除自由基的抗氧化能力。在本研究中，在動物實驗中，利用5~6週齡wistar品系的公鼠，觀察給予NAC能否提升巴拉刈中毒大鼠中存活率，並且測量大鼠體內˙O2-、GSH、LPO(Lipid peroxidation)及發炎指標PGE2(Prostaglandin E2)與NO(Nitric oxide)，研究NAC對於巴拉刈所造成的氧化性壓力（oxidative stress）及發炎反應的拮抗作用；透過細胞實驗，利用小鼠巨噬細胞(RAW 264.7)與人類呼吸道上皮細胞(BEAS-2B)細胞株，進一步來探討NAC對於抗發炎反應的影響。動物實驗結果顯示，PQ(Paraquat)組僅給予腹腔注射PQ一次；PQ+NAC組則在腹腔注射巴拉刈後的2、6、10、14小時後，同以腹腔注射方式給予NAC100mg/kg，總共給予四次(總接受劑量 400mg/kg)，結果發現NAC可以提升PQ中毒大鼠(70mg/kg)於72小時之內的存活率。氧化壓力的實驗結果顯示，NAC能夠顯著的減少巴拉刈6小時內所誘導全血中˙O2-的含量;且能顯著減低巴拉刈在24小時內所誘導血清中LPO與NO含量，而在中毒大鼠體內肺、肝、腎組織中發現，NAC能顯著的增加其GSH含量。根據上述結果顯示，NAC可以對抗PQ所造成的氧化性傷害。另外以細胞實驗對於發炎機制做進一步的探討，根據結果顯示，NAC對巴拉刈所誘導BEAS-2B細胞發炎因子NO具抑制作用，西方墨點法則觀察到RAW 264.7與BEAS-2B細胞中iNOS與COX-2蛋白被抑制的結果。綜合上述結果，NAC對抗巴拉刈在氧化性傷害與發炎作用方面具有一定程度的效果，因此，本研究有助於釐清NAC對抗巴拉刈急毒性的保護機轉。

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