Dingchuantang decoction restores the imbalance of TH2/TH1 in mice infected by respiratory syncytial virus / 中国当代儿科杂志

ABSTRACT

<p><b>OBJECTIVE</b>Dingchuantang is a traditional Chinese medicine decoction which has the Qing, Xuan and Jiang components which have the ability to dispel (Xuan), depress (Jiang) and heat clear or febrigugal (Qing). It has been used for asthma and respiratory syncytial virus (RSV) infection. However, the therapeutic mechanisms of the decoction have not been identified. To understand the mechanism of the anti-RSV property of Dingchuantang, this study investigated the effects of Dingchuantang and its three components on the levels of interleukin-4 (IL-4) and interferon-gamma (gamma-IFN) in mice infected by RSV.</p><p><b>METHODS</b>One hundred and twenty mice were randomly assigned into Normal, Infected, Dingchuantang-treated, Qing component-treated, Xuan component-treated and Jiang component-treated groups (n=20 each). The RSV infection model was prepared in the rats from the last 5 groups. The 4 treatment groups were administered with Dingchuantang, Qing component, Xuan component and Jiang component by gastric lavage respectively 2 hrs after RSV innoculation. The contents of RSV in the lungs were tested by reverse transcription polymerase chain reaction (RT-PCR). The levels of IL-4 and gamma-IFN in broncho-alveolar lavage fluid (BALF) were measured by enzyme linked immunosorbent assay (ELISA).</p><p><b>RESULTS</b>The contents of RSV of lungs in the Dingchuantang-treated group, and Qing and Xuan component-treated groups were significantly lower than those in the untreated Infected group. There was no significant difference between the Jiang component-treated and the Infected group. Dingchuantang treatment decreased the IL-4 level and increased the gamma-IFN level. The Xuan and Jiang component treatment decreased the IL-4 level but had no effect on the gamma-IFN level, while the Qing component treatment increased the gamma-IFN level but had no effect on the IL-4 level.</p><p><b>CONCLUSIONS</b>Dingchuantang can inhibit RSV reproduction and this effect works by Qing and Xuan components. Dingchuantang can also restore the imbalance TH2/TH1 by depressing IL-4 levels, worked by Xuan and Jiang components, and increasing gamma-IFN levels, worked by Qing component.</p>