OBJECTIVETo observe effect of Shufeng Xuanfei Recipe (SXR) and Jiebiao Qingli Recipe (JQR) on mRNA and protein expressions of Toll-like receptor 7 (TLR7), myeloid differentiation factor 88 (MyD88), and nuclear factor-kappaB (NF-kappaB) in mice infected with influenza virus FM1.

METHODSOne hundred and eight mice were randomly divided into nine groups, i.e., the normal control group, the model group, the Oseltamivir group (at the daily dose of 2.5 g/mL), the high dose SXR group (at the daily dose of 3.762 g/kg), the middle dose SXR group (at the daily dose of 1.881 g/kg), the low dose SXR group (at the daily dose of 0.941 g/kg), the high dose JQR group (at the daily dose of 4.368 g/kg), the middle dose JQR group (at the daily dose of 2.184 g/kg), and the low dose JQR group (at the daily dose of 1.092 g/kg), 12 in each group. All mice were mildly anesthetized by ether. Mice in the normal control group were treated by nasal drop of 0.05 mL normal saline, while mice in the rest groups were infected by nasal drop of 0.05 mL influenza virus strain FM1 (LD50). The successful modeling rate was 100%. All medication was performed by gastrogavage 2 h after infection. Distilled water was given by gastrogavage to mice in the normal control group and the model group at the daily dose of 0.2 mL, each time per day for 4 successive days. mRNA expressions of TLR7, MyD88, and NF-kappaB in the lung tissue were determined by Western blot.

RESULTSCompared with the normal control group, mRNA expressions of TLR7, MyD88, and NF-kappaB increased in the model group (P < 0.01). Compared with the model group, mRNA and protein expressions of TLR7, MyD88, and NF-kappaB decreased in the Oseltamivir group, the high, middle, and low dose SXR groups (P < 0.05, P < 0.01); mRNA and protein expressions of TLR7 and NF-kappaB decreased in the high and middle dose JQR groups (P < 0.05, P < 0.01); mRNA expressions of MyD88 decreased in the high and middle dose JQR groups (P < 0.05); protein expressions of MyD88 decreased in the middle dose JQR group (P < 0.05); protein expressions of TLR7 and NF-kappaB decreased in the low dose JQR group (P < 0.05). Compared with the Oseltamivir group, protein expressions of MyD88 decreased in the low dose SXR group (P < 0.05); protein expressions of NF-kappaB decreased in the middle and low dose SXR groups (P < 0.01); mRNA and protein expressions of TLR7 (P < 0.05, P < 0.01), and protein expressions of MyD88 (P < 0.01) decreased in the high, middle, and low dose JQR groups; mRNA and protein expressions of NF-kappaB decreased in the low dose JQR group (P < 0.05, P < 0.01).

CONCLUSIONSEach dose SXR and middle dose JQR could down-regulating the activity of NF-kappaB through adjusting MyD88 dependent TLR signal pathway, thus fighting against influenza virus. SXR was more effective than JQR.