Department of Renal Care, College of Medicine, Kaohsiung Medical University, Ping-Tung 907, Taiwan.
J Ethnopharmacol. 2011 Oct 11;137(3):1149-55. doi: 10.1016/j.jep.2011.07.043. Epub 2011 Jul 22.
Liu-He-Tang (LHT) has been used to treat adult respiratory tract infection with productive cough and fever for a thousand years in ancient China. Adults with respiratory tract infection of human respiratory syncytial virus (HRSV) can have symptoms similar to those managed by LHT. Therefore, LHT is supposed to be beneficial for adult HRSV infection. However, LHT does not have any antiviral activity to support its use against HRSV infection.
HRSV is the most important virus causing serious pediatric respiratory tract infections worldwide. HRSV also contributes considerably to respiratory tract illness in adults. There is no effective therapeutic modality against HRSV infection. In order to find readily available agents to manage adult HRSV infection, this study tested the hypothesis that LHT has antiviral activity against HRSV-induced cytopathy.
Effect of the hot water extract of LHT on HRSV was tested by plaque reduction assay in both human upper (HEp-2) and low (A549) respiratory tract cell lines and also a human normal fibroblast cell line (WI-38). Ability of LHT to stimulate anti-viral cytokines was evaluated by enzyme-linked immunosorbent assay (ELISA).
LHT could dose-dependently inhibit HRSV-induced plaque formation (p < 0.0001), especially in A549 cell. 300 μg/ml LHT nearly abolished plaque formation in A549 cells. LHT was more effective when given before viral inoculation (p < 0.0001). LHT dose-dependently inhibited viral attachment (p < 0.0001). Besides, LHT could inhibit HRSV internalization both time-dependently and dose-dependently (p < 0.0001). Furthermore, LHT stimulated epithelial cells to secrete IFN-β and TNF-α to counteract HRSV infection before infection becomes established.
LHT has anti-HRSV activity that provides a basic support of its possible use in managing adult HRSV infection.
在中国古代，六合汤（LHT）已被用于治疗有痰热咳嗽的成人呼吸道感染。感染人类呼吸道合胞病毒（HRSV）的成年人可能会出现与六合汤治疗类似的症状。因此，六合汤可能对成人 HRSV 感染有益。然而，六合汤没有任何抗病毒活性来支持其用于治疗 HRSV 感染。
HRSV 是导致全球严重儿科呼吸道感染的最重要病毒。HRSV 也对成人呼吸道疾病有很大贡献。目前尚无针对 HRSV 感染的有效治疗方法。为了寻找易于获得的药物来治疗成人 HRSV 感染，本研究检验了以下假设，即 LHT 对 HRSV 诱导的细胞病变具有抗病毒活性。
通过在人上呼吸道（HEp-2）和下呼吸道（A549）细胞系以及人正常成纤维细胞系（WI-38）中进行蚀斑减少测定，检测 LHT 热水提取物对 HRSV 的作用。通过酶联免疫吸附测定（ELISA）评估 LHT 刺激抗病毒细胞因子的能力。
LHT 可剂量依赖性地抑制 HRSV 诱导的蚀斑形成（p < 0.0001），尤其是在 A549 细胞中。300μg/ml 的 LHT 几乎完全抑制了 A549 细胞中的蚀斑形成。LHT 在病毒接种前给药时效果更好（p < 0.0001）。LHT 剂量依赖性地抑制病毒附着（p < 0.0001）。此外，LHT 可时间和剂量依赖性地抑制 HRSV 内化（p < 0.0001）。此外，LHT 可在感染建立之前刺激上皮细胞分泌 IFN-β 和 TNF-α 来对抗 HRSV 感染。
LHT 具有抗 HRSV 活性，为其在治疗成人 HRSV 感染中的可能应用提供了基础支持。
