Hops β-acids (Humulus lupulus) decrease intestinal gene expression of proinflammatory cytokines in an ex-vivo model

The objective of this study was to evaluate the intestinal gene expression of cytokines in pullets, during the tissue exposure to hops beta-acids and lipopolysaccharides (LPS), using an ex-vivo model. To analyze the intestinal gene expression, ileum of pullets was collected, and maintained for 1 hour in Dulbecco's Modified Eagle Medium (DMEM) according to the following 6 treatments: Control (DMEM only); DMEM + 30 ppm of hops beta-acids (45%); DMEM + 240 ppm of hops beta-acids (45%); DMEM + 30 ppm of hops beta-acids (45%) + LPS (10 mu g/mL); DMEM + 240 ppm of hops beta-acids (45%) + LPS (10 mu g/mL) and DMEM + LPS (10 mu g/mL). The expression of IL-1 beta; IL-6; IFN-gamma; IL-4 and IL-10 was analyzed using Real Time PCR. The hops beta-acids or LPS had no effect on IL-4 and IL-10 expression (P > 0.05). However, hops beta-acids decreased IL-1 beta and IFN-gamma expression (P < 0.05), whereas LPS stimulated the expression of those cytokines (P < 0.05). When hops beta-acids and LPS were combined, the lower level of hops beta-acids decreased expression of IL-1 beta. In conclusion, the hops beta-acids showed anti-inflammatory activity, and have potential to modulate the immune system of animals exposed to antigens.