十字花科蔬菜衍生物對 Lipopolysaccharide 與 Interferon-γ 所誘導之一氧化氮的影響

(1)

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本研究主要以小老鼠巨噬細胞 RAW 264.7 為實驗模式，探討十字花科蔬菜衍生物 ß-phenylethyl isothiocyanate (PEITC) ， indole-3-carbinol (I3C) 與 indolo[3,2-b]carbazole (ICZ) 對 lipopolysaccharide (LPS) 與 inte rferon-γ (IFN-γ) 所誘導之一氧化氮 (NO) 生成抑制的影響。結果指出，細胞於添加 PEITC (5x10-11 ~ 10-5 M) 與 I3C ( 10-10~ 10-4 M) 後 24 小時，可抑制因 LPS 與 IFN-γ 所誘導 NO 生成的作用 (p < 0.05) ，且 PEITC 在高濃度下呈現劑量關係；反之， ICZ 則不具顯著抑制作用。 Western blot 與 RT-PCR 分析結果顯示， PEITC 與 I3C 可抑制 R AW 264.7 細胞中 LPS 與 IFN-γ 所誘導之一氧化氮合成酉每 (inducible nitric oxide synthase, iNOS) protein 及 mRNA 之合成，且隨劑量增加 P EITC 抑制作用更為顯著。總言之，十字花科蔬菜衍生物 PEITC 與 I3 C 可藉由抑制 iNOS 基因之轉錄作用，而抑制 mRNA 與 protein 表現

，進而抑制 RAW 264.7 細胞中因 LPS 及 IFN-γ 所誘導 NO 之生成，

而 ICZ 則不具明顯抑制 NO 生成的作用。

(2)

Suppression of Lipopolysaccharide and Interferon- γ Induced Nitric Oxide Production by Cruciferous

Vegetable Derivatives

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Glucosinolate derivatives, including ß-phenylethyl isothiocyanate (PEITC), indole- 3-carbinol (I3C) and indolo[3,2-b]carbazole (ICZ), are thought to be the bioactive c omponents in cruciferous vegetables. Pieces of evidence indicate that certain biolog ical effect evoked by cruciferous vegetable derivatives is closely associated with nit ric oxide (NO). In the present study, we investigated the glucosinolate derivatives P EITC, I3C and ICZ on the inhibition of the nitric oxide production in lipopolysacch aride (LPS) plus Interferon-γ(IFN-γ) stimulated RAW 264.7 cells. The results show ed that PEITC (5x10-11 ~ 10-5 M) or I3C (10-10 ~ 10-4 M) could inhibit LPS plus IFN-γinduced nitric oxide production in RAW 264.7 cells after 24 h treatment (p <

十字花科蔬菜衍生物對 Lipopolysaccharide 與 Interferon-γ 所誘導之一氧化氮的影響



Suppression of Lipopolysaccharide and Interferon- γ Induced Nitric Oxide Production by Cruciferous

Vegetable Derivatives

0.05), and PEITC at high concentrations showed a dose-dependent response. Where

as ICZ showed no such dose effects. Western blot and RT-PCR analysis indicated t

hat PEITC and I3C could inhibit LPS plus IFN-γinduced expression of inducible nit

ric oxide synthase （ iNOS ） protein and mRNA, respectively. Parallel to the NO

production, PEITC had a significant dose-dependent inhibition on the iNOS protein

and mRNA. In conclusion, cruciferous vegetable derivatives, PEITC and I3C could

suppress LPS plus IFN-γinduced NO production by inhibiting iNOS gene transcript

ion. However, ICZ did not have the significant inhibitory effect.