Study On The Inhibition Effect Of Radix Astragali On The Activation Of NF-κB And The Expression Of TNF-a In Peripheral Blood Mononuclear Cell Of Acute Kawasaki Disease

Objective: To explore the inhibition effect of Radix Astragali on the activation of nuclear factor-kappa B (NF-κB) and the subsequent expression of tumor necrosis factor-α(TNF-α) in peripheral blood mononuclear cell (PBMC) of the acute phase of Kawasaki disease (KD).Methods: PBMC was isolated and purified from blood of forty children including twenty KD children and twenty normal ones by density gradient centrifugation. In every sample, PBMC was divided into five groups. The first group was cultured naturally, the second one was stimulated by phorbol 12-myristate-13-acetate (PMA), other groups were stimulated by PMA and Radix Astragali which was treated with different concentration of Radix Astragali (25mg/ml, 50mg/ml, 100mg/ml). Every group was then cultured for forty eight hours. Activation of NF-κB in PBMC was determined by immunocytochemical staining, and enzyme-linked immuosorbent assy (ELISA) was used to measure the concentration of TNF-αin supernatant.Results: (1) Under natural culturing, only a bit of NF-κB positive cells and TNF-αprotein in the cultured supernatant were observed both in KD group and normal group , but there was a significant difference between the two groups (P=0.000). (2) Stimulating PBMC by PMA, the percentage of NF-κB activated cells and the content of TNF-αprotein in supernatant were markedly increased both in KD and normal group, but there was a significant difference between the two groups (P=0.000); Comparing with the group under natural culturing, there was a significant difference (P=0.000). (3) The percentage of NF-κB activated cells was significantly reduced by three different concentration Radix Astragali groups, and the content of TNF-αin the cultured supernatant was also markedly decreased. The KD group had a significant difference with the normal group (P=0.000). Comparing with the group stimulated by PMA, there was a significant difference (P=0.000). While no difference was found between the group inhibited by Radix Astragali and that cultured naturally (P>0.05) (4) There was no difference in three groups which treated with different concentration of Radix Astragali (25mg/ml, 50mg/ml, 100mg/ml), (P=0.000). (5) There was obvious positive correlation between the activation of NF-κB in PBMC and the expression of TNF-αin the cultured supernatant (r =0.601,P = 0.005).Conclusion: Radix Astragali can inhibit the activation of NF-κB and the expression of TNF-αin PBMC of acute Kawasaki disease.