In vivo treatment with the herbal phenylethanoid acteoside ameliorates intestinal inflammation in dextran sulphate sodium-induced colitis

Recently we demonstrated that in inflammatory bowel disease (IBD) macrophage-oxidative burst activity is increased and NADPH oxidase mRNA is induced. The herbal phenylethanoid acteoside isolated from Plantago lanceolata L. was shown to exhibit anti-oxidative potential. Using the dextran sulphate sodium (DSS)-induced colitis model, in this study we have assessed whether systemic application of acteoside affects colitis. Colitis was induced by DSS in Balb/c mice. Treatment with acteoside (120, 600 μg/mouse/day) was performed intraperitoneally. The colon lengths were determined. Colonic tissue was scored histologically (max. score 8) by a blinded investigator. T cells isolated from mesenteric lymph nodes (MLN) were stimulated with anti-CD3 antibody in the presence of interleukin (IL)-2 (final concentration 10 U/ml). After incubation for 24 h, IL-1β, IL-6, IL-12 tumour necrosis factor (TNF)-α and interferon (IFN)-γ levels in supernatants were analysed by the beadlyte® cytokine detection system. Histological scoring of colonic tissue revealed that application of acteoside was followed by a significantly improved histological score. In acute colitis the histological score was 3·2 with acteoside versus 5·2 with phosphate-buffered saline (PBS) (P < 0·02). In chronic colitis both 120 μg (3·3 versus 5·2) or 600 μg acteoside (3·0 versus 5·2) significantly ameliorated colitis (both P < 0·02). Stimulated MLN from mice with chronic DSS-induced colitis treated with acteoside showed a significant down-regulation of IFN-γ secretion (195 pg/ml with 600 μg acteoside versus 612 pg/ml with PBS, P < 0·02). Inhibition of oxidative burst activity with acteoside reduced mucosal tissue damage in DSS colitis and could be a therapeutic alternative for IBD treatment. Further studies of this agent are warranted.