Abstract: Objective: To investigate the effects of Radix Angelicae Sinensis (RASI) and hydrocortisone combination on the murine asthma model and the mechanism. Methods: BALB/c mice were randomly divided into control group, blood stasis model group, asthma model group, HSS group, RASI group and RASI+HSS group (n=12). Ovalbumin (OVA) was used to replicate mice asthma model and hydrocortisone sodium succinate (HSS) to copy blood stasis model. Effects of RASI, HSS and their combination on hemorheology, anti-asthma (asthmatic behaviors, lung function, lung index and water content in lung tissue) were observed. and anti-asthma mechanisms The expression of relative cytokines, high-mobility group box 1 (HMGB1), toll-like receptor 4 (TLR4) and nuclear factor-κB (NF-κB) was detected by ELISA and immunohistochemistry respectively. Results: Eight g/kg RASI, 0.05 g/kg HSS and their combination could significantly relieve asthma behavioral indicators, improve lung function, reduce lung index and water content in lung tissue, decrease the levels of TNF-α, IL-1β and IL-6 in broncho-alveolar lavage fluid (BALF), and inhibit the high expression of HMGB1, TLR4 and NF-κB in lung tissue. The improvement of lung function and the decrease in level of relative cytokines (TNF-α、IL-1β及IL-6) were better in RASI+HSS group than those in RASI group and HSS group, and the inhibition of protein expression of TLR4 and NF-κB was also too. Combined administration of RASI and hydrocortisone could decrease serum thromboxane B2 (TXB2) content and blood viscosity, which were increased induced by hydrocortisone. Conclusion: Combined administration of RASI and hydrocortisone have obvious anti-asthma effects and one of the mechanisms is to inhibit protein synthetization of HMGB1, TLR4 and NF-κB.The combined administration of RASI and hydrocortisone has stronger improvement of lung function than that of RASI and hydrocortisone alone, and it may be related to the inhibition of TLR4 and NF-κB synthetization. The combined administration of RASI can alleviate abnormal changes of hemorheology induced by hydrocortisone in treatment of asthma.

Key words: Radix Angelicae Sinensis (RASI), hydrocortisone, mouse, asthma, high-mobility group box 1 (HMGB1), Toll-like receptors 4 (TLR4), nuclear factor-κB (NF-κB), hemorheology