Division of Hepatobiliary Pancreatic Surgery, Department of Surgery, Kaohsiung Medical University, Kaohsiung, Taiwan.
Am J Chin Med. 2009;37(2):383-94. doi: 10.1142/S0192415X09006904.
Human infection by enterovirus type 71 (EV71) can cause life-threatening meningo-encephalitis. Currently, there is no effective anti-EV71 therapy available. Since EV71 infection commonly involves skin lesions, we tested our hypothesis that water extract of Glycyrrhiza uralensis (G. uralensis) could inhibit the cytopathic effects of EV71 in a human foreskin cell line by using an XTT-based method. Our results showed that the water extract of G. uralensis at 3,000 microg/ml has only 30% cytotoxicity on host cells, and furthermore, that the water extract of G. uralensis at 0.1 microg/ml could effectively protect host cells against EV71 infection (p < 0.0001). The half maximal inhibitory concentration (IC(50)) was 0.056 microg/ml with a selective index greater than 50,000. The water extract of G. uralensis exerted its effects not only by preventing viral attachment (p < 0.0001), but also by inhibiting the penetration of the virus (p < 0.0001). EV71 infection caused cells to produce significant amounts of IFN-beta (p = 0.0003). However, the anti-EV71 activity of the water extract of G. uralensis was not mediated by IFN. In conclusion, the water extract of G. uralensis possesses potent anti-EV71 effects with less cytotoxicity. Its low IC(50) and high 50% cytotoxic concentration (CC(50)) values suggest that it is a promising anti-EV71 agent.
人类肠道病毒 71 型（EV71）感染可引起危及生命的脑膜炎。目前尚无有效的抗 EV71 疗法。由于 EV71 感染常伴有皮肤损伤，我们通过 XTT 法检测了甘草水提取物（G. uralensis）抑制人包皮细胞系中 EV71 致病变效应的假说。结果表明，甘草水提取物在 3000μg/ml 时对宿主细胞的细胞毒性仅为 30%，而 0.1μg/ml 的甘草水提取物可有效保护宿主细胞免受 EV71 感染（p＜0.0001）。半最大抑制浓度（IC50）为 0.056μg/ml，选择指数大于 50000。甘草水提取物的作用不仅在于阻止病毒附着（p＜0.0001），还在于抑制病毒渗透（p＜0.0001）。EV71 感染导致细胞产生大量 IFN-β（p=0.0003）。然而，甘草水提取物的抗 EV71 活性并非通过 IFN 介导。总之，甘草水提取物具有较强的抗 EV71 作用且细胞毒性较小。其低 IC50 和高 50%细胞毒性浓度（CC50）值表明它是一种很有前途的抗 EV71 药物。
