Study on the regulation of T-bet/GATA-3 expression and Th imbalance by Salvia miltiorrhiza coordinated with dexamethasone in rats with asthma

Objective To study the regulation of the expression of T-box expressed in T cells(T-bet)and GATA binding protein(GATA-3)and imbalance of Th lymphocytes by Salvia miltiorrhiza and dexamethasone in asthmatic rats. Methods Eighty SD rats were randomly divided into 4groups(each n=20),including asthma model group,normal control group,Salvia miltiorrhiza group and the combined medication group(Salvia miltiorrhiza combined with dexamethasone).The airway responsiveness was observed,lung tissues of SD rats were stained with HE and subject to pathologic examinations.The expression of T-bet and GATA-3in the lung tissues was detected by western-blots.The levels of interleukin-4(IL-4)and interleukin-5(IL-5)in lung tissue homogenates were detected by ELISA. Results The inflammation in the lung pathological slices of rats was milder in Salvia miltiorrhiza group and the combined medication group than in the asthma model group,and the inflammation in the combined medication group was reduced more.Airway resistance was as follows;asthma model group Salvia miltiorrhiza group the combined medication group normal control group(all P0.05);moreover,it increased with increasing histamine concentration for each group.The T-bet level exhibited as follows:normal control groupcombined medication groupSalvia miltiorrhiza groupasthma model group(all P0.01);however,the level of GATA-3showed a striking contrast.The level of IFN-γin lung tissue homogenates showed as follows:normal control groupcombined medication group Salvia miltiorrhiza groupasthma model group(all P0.01);however,the level of IL-4showed a striking contrast.The lung T-bet/GATA-3level was positively correlated with the IFN-γlevel(γ=0.787,P0.01)and the ratio of IFN-γ/IL-4(γ=0.893,P0.01),but negatively correlated with the IL-4level(γ=-0.816,P0.01). Conclusions Salvia miltiorrhiza injection may up-regulate the expression of T-bet/GATA-3and help correct Th1/Th2 imbalance.It plays a synergistic role in anti-inflammation with dexamethasone.