Effect of the Haoqinqingdan decoction on damp-heat syndrome in rats with influenza viral pneumonia

OBJECTIVE: To investigate the effect of Chinese medicine prescription-Haoqinqingdan decoction on damp-heat syndrome in rats with influenza viral pneumonia and its influence on the immune function. METHODS: A total of 48 Wistar rats were randomly divided into the normal control group, the damp-heat syndrome model group, the Haoqinqingdan decoction group (high, medium and low dose group) and the ribavirin group. The body temperature and weight of rats in each group were recorded after modeling. After treatment for 6 d, the concentration of T lymphocyte subgroup (CD3(+)CD4(+), CD3(+)CD8(+)) was determined by flow cytometry. The OD value of IFN-γ/IL-4 was detected by double-antibody sandwich ELISA method, and its concentration was acquired through conversion. RESULTS: After modeling, the temperature and weight of rats in each modeling group showed the increasing trend (P<0.01). From the second day of treatment, there was significant difference in the body mass between groups, and the rat weight of the control group was higher than in the modeling group (P<0.05 or 0.01). With the advances of treatment, only the temperature in the medium and high dose Haoqinqingdan decoction groups declined significantly (P<0.05). After treatment, the CD4(+)/CD8(+) ratio of the damp-heat syndrome model group decreased more significantly compared with the control group. Elevated CD3(+) CD8(+) percentages and declined CD4(+)/CD8(+) ratios can be observed in the low dose group and ribavirin group (P<0.05). Moreover, the CD3(+) CD4(+) percentage of ribavirin group was lower than in the control group (P<0.05). After treatment, the IFN-γ and IFN-γ/ IL-4 levels in the peripheral blood of rats in the damp-heat syndrome group were obviously higher than in the control group (P<0.05). CONCLUSIONS: Compared with ribavirin, the high dose Haoqinqingdan decoction can improve the ratio of T lymphocyte subgroup and Th1/Th2 cell balance more effectively.