Immunoregulatory Effects of Water Extracts of Scutellariae Radix in DSS-Induced Inflammatory Bowel Disease Animal Model

Lee, Sun Hee; Lim, Beong Ou; Choue, Ryo Won

Abstract

Scutellariae Radix (Scu.), one of the immune-regulatory substances, is recognized to play the role in the metabolic process of inflammation, allergy and immunity. It has been traditionally used in the Oriental medicine to treat inflammatory bowel diseases (IBD). The purpose of this study was to evaluate the effects of water extracts of Scutellariae Radix on the spleen lymphocyte immune function in the Balb/c female mice treated with dextran sodium sulfate (DSS) to induce colitis. Water extract of Scutellariae Radix (100 mg/kg) and sulfasalazine (50 mg/kg) were administrated orally for 2 weeks of experimental period. Mice were divided into three experimental groups randomly: DSS group (5% DSS was ad libitum for 5 days) as control group, DSS + Scu. (water extracts of Scutellariae Radix for 2 weeks after 5% DSS was ad libitum for 5 days) as experimental group, and DSS + Sulfasalazine group (Sulfasalazine for 2 weeks after 5% DSS was ad libitum for 5 days) as positive control group. Levels of Ig A, Ig E, CD4(+), CD8(+), TNF-alpha and other cytokines were measured. Treatment of DSS for 5 days induced bowel inflammation and the treatment with Scu. water exteract and sulfasalazine significantly recovered the damage. The length of intestine of DSS group was significantly shorter than that of other groups. The serum and fecal concentration of Ig A of SS + Scu group was higher than those of DSS group. The contents of CD4(+) T cells was higher in the DSS + Scu. group than the other groups and CD8(+) T cells was the lowest in DSS + Sulfasalazine group. The Ig A level of cultured supernatant of spleen lymphocyte was the highest, while the Ig E level was the lowest in SS + Scu group. The concentration of TNF-alpha, cytokine secreted from the Th1 cell in the supernatant spleen lymphocyte, was the highest in the DSS group and the lowest in the DSS + Scu. group. The concentration of IFN-gamma and lL-12 was lower in the DSS + Scu. group than those of the other groups. The concentration of IL-4 in the supernatant of spleen lymphocyte was the lowest in the DSS + Scu. group but IL-10 was not significantly different. Based on these findings, water extract of Scutellariae Radix exhibited the inhibitory effect via IL-4 production thereby inhibited the production of Ig E and strengthened immune system, and alleviated injury in DSS-induced colitis mice model.