[Effects of Cordyceps extract on cytokines and transcription factors in peripheral blood mononuclear cells of asthmatic children during remission stage].

OBJECTIVE

To explore the effects of Cordyceps extract in regulating the imbalance of Th1/Th2 ratio and inhibiting the inflammatory reaction, and to find the theoretical basis of Cordyceps extract for treating asthma in remission stage.

METHODS

A total of 20 peripheral venous blood samples (3 mL) were collected from 20 asthmatic children during remission stage, and peripheral blood mononuclear cells (PBMCs) were separated by Ficoll method. PBMCs were separated into three groups (blank group, low-dose group and high-dose group). The PBMCs were incubated in vitro for 48 hours in the absence (blank group) or presence (low-dose group and high-dose group) of Cordyceps extract at different concentrations (10, 20 microg/mL). The expressions of interferon-gamma (IFN-gamma), interleukin-4 (IL-4), IL-10, T-box expressed in T cells (T-bet), GATA-binding protein-3 (GATA-3) and forkhead/winged-helix transcription factor-3 (Foxp3) mRNAs in PBMCs were measured by real-time fluorescent quantitative polymerase chain reaction, and the contents of IFN-gamma, IL-4 and IL-10 in supernatants were measured by enzyme-linked immunosorbent assay.

RESULTS

The expressions of IFN-gamma mRNA showed no significant differences among the three groups. The expressions of the IL-4 mRNA in the high-dose group and the low-dose group were lower than that in the blank group (P=0.014, P=0.011). The expression of IL-10 mRNA in the high-dose group was higher than that in the blank group (P=0.034). And the differences of the IFN-gamma mRNA/IL-4 mRNA ratio presented no statistic significance among the three groups. The level of IL-4 content in the high-dose group was lower than that in the blank group (P=0.018), but the level of IL-10 content, and ratio of IFN-gamma/IL-4 in the high-dose group were higher than those in the blank group (P=0.011, P=0.045). The differences of the IFN-gamma presented no statistic significance among the three groups. The T-bet/GATA-3 ratio and Foxp3 mRNA expression in the high-dose group were higher than those in the blank group (P=0.001, P=0.015). There was significant difference in expression of GATA-3 mRNA between the high-dose group and the blank group (P=0.028), and between the low-dose group and the blank group (P=0.019). The expression differences of T-bet mRNA were insignificant between any two groups.

CONCLUSION

Cordyceps extract can inhibit the proliferation and differentiation of Th2 cells and reduce the expression of related cytokines by down-regulating the expression of GATA-3 mRNA and up-regulating the expression of Foxp3 mRNA in PBMCs. Meanwhile, it can alleviate the chronic allergic inflammation by increasing the content of IL-10.