Shashen-Maidong Decoction-Mediated IFN-γ and IL-4 on the Regulation of Th1/Th2 Imbalance in RP Rats

Objective. Studying correlative changes of Th1/Th2 (Th, Helper T cells) related factor Interferon-gamma (IFN-gamma) and Interleukin-4 (IL-4) in the progression of radiation pneumonia (RP) rats and the efficacy of Shashen-Maidong decoction on these indexes to explore the immune mechanism of the decoction on the prevention and treatment of RP. Methods. Male 60 Sprague-Dawley (SD) rats were randomly divided into four groups. In addition to the normal control group taking saline, the other rats were set up RP model treated with Shashen-Maidong decoction or dexamethasone (DXM), respectively. The IFN-gamma and IL-4 concentrations in serum and bronchoalveolar lavage fluid (BALF) of rats were tested in the 2nd and 4th week after radiation, and the relative ratio of IFN-gamma/IL-4 was calculated. Results. (1) There was significant difference of serum IL-4 concentrations in group B (p<0.01) and extreme difference in groups C and D (p<0.001) compared with group A in 4th week. Compared with group D, IL-4 concentrations in group B increased significantly in both 2nd and 4th week (p<0.01). Group B had significantly decreased IFN-gamma concentrations in BALF (p<0.001) compared with group D in the 4th week. And IFN-gamma concentrations in BALF in group B were increased compared with group C in the 4th week (p<0.05). (2) There was no difference of the relative ratio of IFN-gamma/IL-4 at each time in groups B and A for both serum and BALF, while the ratios in groups C and D in 4th week in BALF were increased (p<0.05) compared to group A. Conclusion. Shashen-Maidong decoction can improve the immune function of RP rats by increasing IFN-gamma concentration and decreasing IL-4 concentration, possibly by increasing the relative ratio of IFN-gamma/IL-4 to regulate the immune imbalance of Th1/Th2.