Effects of Qingfei Oral Liquid on the expressions of IL-10 and IL-17 in the lung tissue and those of Treg and Th17 in the spleen of RSV-infected mice / 医学研究生学报

ABSTRACT

Objective The action mechanisms of Qingfei Oral Liquid ( QFOL) in the treatment of respiratory syncytial virus ( RSV) infection need to be studied more deeply.The aim of this study is to examine the expressions of interleukin ( IL)-10 and IL-17 in the lung tissue and those of Treg and Th17 in the spleen tissue of RSV-infected mice before and after treated with QFOL, and to explore the action mechanisms of QFOL from the perspective of the Treg/Th17 cy-tokines balance. Methods Fifty BABL/c mice were equally ran-domized to five groups blank control, RSV model, Ribavirin, low-dose QFOL, and high-dose QFOL.Models of RSV ( long strain) infec-tion were made in the latter four groups.At 48 hours after viral activa-tion, the mice of the control and RSV model groups were treated intragastrically with 0.9%normal saline and those in the Ribavirin and QFOL groups with Ribavirin at 0.0025 g/mL and QFOL at 1.33 g/mL and 4 g/mL, respectively, all for 72 hours.Then all the mice were killed and the lung tissue harvested from 5 animals in each group for pathological analysis, while the levels of IL-10 and IL-17 in the bronchoalveolar lavage fluid of the other 5 detected by ELISA.The expressions of the cytokines Treg and Th17′in the spleen from 4 mice in each group were determined by flow cytometry. Results Compared with the RSV models, pathologic changes were significantly re-duced in the mice of the QFOL, Ribavirin and control groups (P<0.01), the expression of IL-10 remarkably up-regulated in the low-dose QFOL, high-dose QFOL, Ribavirin, and control groups ([39.21 ±1.57] vs [43.54 ±1.03], [46.64 ±0.48], [47.83 ±0.87], and [50.44 ±1.04] ng/L, all P<0.01), while the level of IL-17 markedly down-regulated ([70.96 ±0.53] vs [55.92 ±0.83], [33.66 ±0.70], [21.92 ±1.38], and [9.42 ±0.59] pg/mL, all P<0.01).The expressions of Treg/Th17′were significantly in-creased in the low-dose QFOL, high-dose QFOL, Ribavirin, and control groups (2.89 ±0.52, 6.38 ±0.36, 3.95 ±0.26, and 3.54 ± 0.85) as compared with that in the RSV models (0.96 ±0.16) (all P<0.01).Both low-and high-dose QFOL groups showed statisti-cally significant differences from the Ribavirin group in the levels of Treg, Th17, and Treg/Th17 (P<0.05). Conclusion QFOL can regulate the balance of Treg/Th17, increase the expression of IL-10 and decrease that of IL-17 in the lung tissue of RSV-infected mice, which further proves the efficacy of QFOL in the treatment of RSV-induced pneumonia.