Polysaccharides derived from Morinda citrifolia Linn reduce inflammatory markers during experimental colitis

Ethnopharmacological relevance: There are many reports of pharmacological activities of extracts and fractions of different vegetable-derived products in the scientific literature and in folk medicine. Ethnopharmacological use of these products by various communities continues to be extensively explored, and they account for more than half of all medications used worldwide. Polysaccharides (PLS) extracted from plants such as Morinda Citrifolia Linn present therapeutic potential in treatment of inflammatory bowel diseases (IBD) such as ulcerative colitis (UC). Aim of the study: To evaluate the anti-inflammatory action of Noni-PLS against the intestinal damage in UC induced by acetic acid in mice. Materials and methods: In acetic acid-induced colitis, the mice were treated intraperitoneally (ip) with Noni-PLS (0.1, 0.3, and 3.0 mg/kg) or subcutaneously (sc) with dexamethasone (2.0 mg/kg) 30 min before euthanasia to determine the best dose of Noni-PLS with an anti-inflammatory effect in the course of UC. The colonic tissue samples were collected for macroscopic, wet weight, microscopic and biochemical (myeloperoxidase (MPO), glutathione (GSH), malondialdehyde (MDA), nitrate/nitrite (NO3/NO2), cytokines, cyclooxygenase (COX-2) and inducible nitric oxide (iNOS)) analyses. Results: Treatment with Noni-PLS reduced the intestinal damage induced by acetic acid as it reduced macroscopic and microscopic scores and the wet weight of the colon. In addition, MPO activity and levels of GSH, MDA, NO3/NO2, pro-inflammatory cytokines, and COX-2 expression reduced. Conclusions: This study suggests that Noni-PLS exhibits anti-inflammatory action against intestinal damage by reducing inflammatory cell infiltration, oxidative stress, pro-inflammatory action of cytokines, COX-2 and iNOS expression in the inflamed colon. Noni-PLS shows therapeutic potential against inflammatory disorders like UC.