霍山石斛联苄类化合物 dendrocandin U 抗炎作用机制研究

为了研究霍山石斛中联苄类化合物 dendrocandin U 的抗炎作用机制，文章建立脂多糖(LPS)诱导的RAW264.7细胞炎症模型，运用Griess法检测NO的释放量，运用实时定量聚合酶链式反应(polymerase chain reaction, PCR)检测诱导型一氧化氮合酶(inducible nitric oxide synthase, iNOS)、肿瘤坏死因子-$\alpha$ (tumor necrosis factor $\alpha$ , TNF- $\alpha$ )和白细胞介素-1β(interleukin-1β, IL-1β)mRNA的表达，运用Western Blot检测核因子 $\kappa$ B(nuclear factor kappa-B, NF- $\kappa$ B)、丝裂原活化蛋白激酶(mitogen-activated protein kinases, MAPKs)和Akt信号通路相关蛋白的表达。研究发现，dendrocandin U可显著抑制LPS诱导的RAW264.7细胞NO释放，iNOS、TNF- $\alpha$ 、IL-1β的mRNA表达( $P<0.01$ )以及 $\mathrm{I}\kappa\mathrm{B}, \mathrm{p}65, \mathrm{ERK}1/2, \mathrm{JNK}1/2, \mathrm{p}38, \mathrm{Akt}$ 磷酸化( $P<0.05$ )。结果表明，dendrocandin U可能是通过抑制NF- $\kappa$ B、MAPKs和Akt信号通路的激活来抑制LPS诱导的RAW264.7细胞炎症反应。

To study the anti-inflammatory mechanism of dendrocandin U from Dendrobium huoshanense, a model of LPS-induced inflammation in RAW264.7 cells was established. The release of NO was detected by Griess method, the mRNA expressions of inducible nitric oxide synthase(iNOS), tumor necrosis factor$\alpha$ (TNF- $\alpha$ ) and interleukin-1 $\beta$ (IL-1 $\beta$ ) were detected by quantitative real-time polymerase chain reaction(RT-qPCR), and the expressions of proteins related to nuclear factor kappa-B(NF- $\kappa$ B), mitogen-activated protein kinases(MAPKs) and Akt signaling pathways were detected by Western blot. The results showed that dendrocandin U significantly inhibited LPS-induced NO release and mRNA expressions of iNOS, TNF- $\alpha$ and IL-1 $\beta$ in RAW264.7 cells ( $P<0.01$ ). Meanwhile, dendrocandin U significantly inhibited LPS-induced phosphorylation of I $\kappa$ B, p65, ERK1/2, JNK1/2, p38 and Akt ( $P<0.05$ ). Dendrocandin U could inhibit LPS-induced inflammatory responses in RAW264.7 cells by inhibiting the activation of NF- $\kappa$ B, MAPKs and Akt signaling pathways.