Objective: To explore the effect of qidong huoxue decoction (QHD) on inflammatory factors and Toll-like receptor (TLR4) mRNA expressions in acute lung injury (ALI) rats.
Methods: Totally 50 healthy male SD rats were randomly divided into the blank control group, the lipopolysaccharide (LPS) model group, low, middle, high dose QHD groups according to body weight, 10 rats in each group. Rats in low, middle, high dose QHD groups were intragastrically administered with QHD at 4, 8, and 16 mL/kg 24, 12 h before modeling and 12 h after modeling, respectively. Normal saline was intragastrically administered to rats in the blank control group and the LPS model group. An ALI rat model was established using intratracheal instillation of LPS. Rats were killed after 24-h modeling. Then the bronchoalveolar lavage fluid was prepared. Contents of TNF-α, IL-1β, and L-10 were detected using ELISA. TLR4 mRNA expressions were determined byreal time PCR.
Results: Compared with the blank control group, contents of TNF-α, IL-1β , and IL-10 increased (P <0. 01), TLR4 mRNA expressions also increased in the LPS model group (all P <0. 01). Compared with the LPS model group, contents of TNF-α and IL-1β decreased (P <0. 05, P <0. 01), IL-10 levels increased (P <0. 01) , TLR4 mRNA expressions were also reduced (P <0. 01), in high and middle dose QHD groups. Compared with the high dose QHD group, con- tents of TNF-α and IL-1β increased in middle and low dose QHD groups (P <0. 05); IL-10 levels decreased (P <0. 05) in the low dose QHD group(P <0. 05), TLR4 mRNA expressions also increased in the low dose QHD group (P <0. 05). Compared with the middle dose QHD group, IL-10 levels was reduced, but TLR4 mRNA expressions increased in the low dose QHD group (P <0. 05).
Conclusions: QHD had the protective effect on LPS induced ALI rats. Its mechanism might be associated with inhibiting TLR4 mRNA expressions, leading to decreased pro-inflammatory cytokines such as TNF-α and IL-β, elevated anti-inflammatory cytokine IL-10, and thereby, correcting unbalanced inflammation.