Haoqin Qingdan Decoction () and ribavirin therapy downregulate CD14 and toll-like receptor 4 in febrile disease with dampness-heat syndrome in a mouse model.

Abstract

To evaluate the effect of Chinese medicine Haoqin Qingdan Decoction (, HQD) for febrile disease dampness-heat syndrome (FDDHS). Forty mice were divided into four groups, including normal control, FDDHS (induced by Radix et Rhizoma Rhei recipe and influenza virus A1 FM1 model), HQD, and the ribavirin groups (10 in each). The normal control and FDDHS groups were administered normal saline. HQD and the ribavirin groups were administered HQD and ribavirin intragastrically once daily at a dose of 64 g/(kg d) and 0.07 g/(kg d), respectively for 7 days. Lethargy, rough hair, diarrhea, tongue color and sole color were evaluated for pathological changes in morphology. The tongue and lung tissues were collected for histology. The CD14 and toll-like receptor 4 (TLR4) expression levels were measured using real-time quantitative polymerase chain reaction. More than 80% of the FDDHS mice showed hypokinesia and lethargy, and pathological changes associated with rough hair, diarrhea, tongue color and sole color. With advanced treatment for 7 days, the thick greasy tongue fur of the HQD and ribavirin groups were thinner than that of the FDDHS group (P<0.05), and it was the thinnest in the ribavirin group as compared with that in other groups (P<0.05). The CD14 and TLR4 expression levels in the lung tissues of HQD and ribavirin groups significantly delined compared with the model group (P<0.05 or P<0.01). CD14 was down-regulated more remarkably in the HQD group compared with the ribavirin group (P<0.05), whereas the converse was true with TLR4 (P<0.05). We established a FDDHS mouse model showing systemic clinical symptoms. Both HQD and ribavirin can inhibit the expression of CD14 and TLR4 in FDDHS mice, while the effect of ribavirin might be much more violent. The expression changes of CD14 and TLR4 consistently refers to lipopolysaccharide, the commonly and hotly inducing factor in FDDHS.