Objective: To investigate the expression of Th1/Th2 inflammatory cytokines IL-2, interferon-γ (IFN-γ), IL-4, and IL-10 in rat treatment model of dextran sulfate sodium (DSS) -induced ulcerative colitis.
Methods: Forty Sprague Dawley (SD) male rats were divided into a normal group, a colitis model group, a sulfasalazine(SASP)-treatment group (SASP group) and a Jiechangning-treatment group ( Jiechangning group) (each group n=10). Disease activity index (DAI) and colorectal histological damage scale were assessed. The expression levels of cytokines IL-2, IFN-γ, IL-4, and IL-10 in the serum and the colon mucosa tissues were detected by enzyme-linked immuno sorbent assay (ELISA) and real time polymerase chain reaction (RT-PCR).
Results: Compared with the colitis model group, the DAI and colorectal histological damage scale were decreased in the Jiechangning group (both P<0.05), but there was no obvious difference compared with the SASP group (P>0.05). There was no significant difference in IL-2 expression both in the serum and the colon mucosa tissues before or after the treatment in various groups (P>0.05). Compared with the colitis model group, IFN-γ level both in the serum and the colon mucosa tissues was decreased in the SASP group and the Jiechangning group, with significant difference in the serum (both P<0.05), but there was significant difference in the colon mucosa tissues only in the Jiechangning group (P<0.05). The serum IL-4 level in the SASP group and the Jiechangning group was increased compared with that in the colitis control group, with significant difference only in the Jiechangning group (P<0.05). There was no difference in IL-4 level in the colon mucosa tissues whether treated or not (P>0.05). IL-10 level both in the serum and the colon mucosa tissues in the SASP group and the Jiechangning group was increased compared with that in the colitis model group, with significant difference (all P<0.05). There was no difference in the expression level of cytokines IL-2, IFN-γ, IL-4, and IL-10 both in the serum and the colon mucosa tissues between the SASP group and the Jiechangning group (all P>0.05).
Conclusion: DSS can break the balance of Th1/Th2 expression in the colon. Jiechangning enema can ameliorate DSS-induced acute experimental colitis in rats by decreasing IFN-γ level and increasing IL-10 level both in the serum and the colon mucosa tissues to regulate the Th1/Th2 balance and improve immunity.