柳松菇甲醇萃取物對於人類肺腺癌 CL-3 細胞中經由烹調油煙造成的環氧合酶-2 誘發表現之抑制效果   全文下載

Preventive Effect of Methanol Extract from Agrocybe cylindracea (MEAC) Mushroom on the Cooking Oil Fumes-Induced Expressions of Cyclooxygenase-2 via Suppression of Nuclear Factor-kappaB (NF–kB) in CL-3 Cells

先前研究指出柳松菇甲醇萃取物（MEAC）具有抑制烹調油煙造成的活性氧和DNA氧化傷害。本文研究目的想進一步探討，柳松菇甲醇萃取物對於烹調油煙誘發人類肺腺癌CL-3細胞之環氧合?-2(COX-2)和細胞色素cytochrome P450（CYP1A1）基因表現之效果。實驗結果顯示，柳松菇甲醇萃取物並不能影響100 μg/mL的烹調油煙所誘發的CYP1A1訊息核糖核酸（mRNA）之表現量，然而，對於烹調油煙所誘發的環氧合?-2 mRNA和蛋白質的表現量均具有顯著性的抑制效果，且呈劑量反應關係。柳松菇甲醇萃取物對於烹調油煙誘發的環氧合?-2蛋白質表現量的半數抑制濃度（IC50）約為500 μg/mL。由此些結果推測，柳松菇甲醇萃取物能選擇性的影響烹調油煙調控的特定基因。已知透過NF-kB路徑能誘發環氧合?-2之表現，本實驗以凝膠遲滯法分析結果得知，柳松菇甲醇萃取物單獨存在下其本身並不會改變核因子-kB (NF-kB)與DNA 鍵結活性，然而在有烹調油煙共存下，隨著濃度的增加而能顯著的抑制烹調油煙所提升的NF-kB與DNA的鍵結活性。綜觀以上結果而知，柳松菇甲醇萃取物透過抑制NF-kB路徑以壓制烹調油煙造成的環氧合?-2之誘發表現。本文結果可用來解釋柳松菇甲醇萃取物為何能具有抑制烹調油煙所造成的活性氧和DNA氧化傷害之效果。

Methanol extract from Agrocybe cylindracea strain B (MEAC) mushroom is reported to suppress reactive oxygen species (ROS) production and DNA oxidative damage induced by cooking oil fumes (COF). This study examined the effects of MEAC on COF-stimulated expression of the cyclooxygenase-2 (COX-2) and cytochrome P450 CYP1A1 genes in human lung adenocarcinoma CL-3 cells. MEAC did not alter COF-stimulated CYP1A1 mRNA expression. However, MEAC significantly inhibited COF (100 μg/mL) stimulation of COX-2 mRNA and protein levels in a dose-dependent manner. The concentration of MEAC that decreased COF-stimulated COX-2 protein expression by 50% was 500 μg/mL. These data suggest that MEAC selectively affects particular types of the COF-mediated genes. COX-2 is reported to be regulated by the nuclear factor-kappaB (NF-kB) pathway. The gel retardation assay was used and showed that MEAC alone did not alter the basal NF-kB DNA binding activity; in the presence of COF, it dose-dependently suppressed COF-increased activity of NF-kB. These data suggest that MEAC may exert its anti-COF action on COX-2 gene expression via the NF-kB pathway. The results of this study support that MEAC mediates the COF-stimulated ROS production and DNA damage in CL-3 lung cancer cells.