McN-A-343, a muscarinic agonist, reduces inflammation and oxidative stress in an experimental model of ulcerative colitis.

AIM: The aim of the present study was to investigate the anti-inflammatory response mediated of the M1 muscarinic acetylcholine receptor (mAChR) during experimental colitis. MATERIAL AND METHODS: After the induction of 6% acetic acid colitis, mice were treated with McN-A-343 0.5, 1.0, and 1.5 mg/kg or dexamethasone (DEXA, 2.0 mg/kg) or pirenzepine (PIR, 10 mg/kg; M1 mAChR antagonist). Colonic inflammation was assessed by macroscopic and microscopic lesion scores, colonic wet weight, myeloperoxidase (MPO) activity, interleukin-1 beta (IL1-ß) levels and tumor necrosis factor alpha (TNF-α), glutathione (GSH), malondialdehyde (MDA) and nitrate and nitrite (NO3/NO2), mRNA expression of IKKα, nuclear factor kappa beta (NF-kB) and cyclooxygenase-2 (COX-2), as well protein expression of NF-kB and COX-2. RESULTS: Treatment with McN-A-343 at a concentration of 1.5 mg/kg showed a significant reduction in intestinal damage as well as a decrease in wet weight, MPO activity, pro-inflammatory cytokine concentration, markers of oxidative stress and expression of inflammatory mediators. The action of the M1 agonist by the administration of pirenzepine, which promoted the blocking of the mAChR M1-mediated anti-inflammatory response, has also been proven. CONCLUSION: The results suggest that peripheral colonic M1 mAChR is involved in reversing the pro-inflammatory effect of experimentally induced colitis, which may represent a promising therapeutic alternative for patients with ulcerative colitis.

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.

Proteins from Plumeria pudica latex exhibit protective effect in acetic acid induced colitis in mice by inhibition of pro-inflammatory mechanisms and oxidative stress.

Latex proteins from P. pudica (LPPp) have anti-inflammatory activity. In the present study, LPPp was evaluated to protect animals against inflammatory ulcerative colitis (UC). UC was induced by intracolonic instillation of a 6% acetic acid solution and the animals received LPPp (10, 20 or 40 mg/kg) by intraperitoneal route 1 h before and 17 h after acetic acid injection. Eighteen hours after instillation of acetic acid, the mice were euthanized and the colons were excised to determine the wet weight, macroscopic and microscopic lesion scores, myeloperoxidase (MPO) activity, IL1-ß levels, glutathione (GSH) and malondialdehyde (MDA) concentration and superoxide dismutase (SOD) activity. The results revealed that LPPp treatment (40 mg/kg) had a protective effect on acetic acid-induced colitis by reducing the wet weight, macroscopic and microscopic scores of intestinal lesions and colonic MPO activity. Additionally, LPPp inhibited tissue oxidative stress, since decreases in GSH consumption, MDA concentration and SOD activity were observed. The treatment with LPPp reduced the levels of cytokine IL-1ß, contributing to the reduction of colon inflammation. Biochemical investigation showed that LPPp comprises a mixture of proteins containing proteinases, chitinases and proteinase inhibitors. These data suggest that LPPp has a protective effect against intestinal damage through mechanisms that involve the inhibition of inflammatory cell infiltration, cytokine release and oxidative stress.

Chemical structure and anti-inflammatory effect of polysaccharide extracted from Morinda citrifolia Linn (Noni).

Polysaccharides extracted from plants are very promising molecules in the field of pharmacotherapy. Knowing this, the aim of this study was to extract, characterize and evaluate the action of the polysaccharide of Morinda citrifolia Linn (Noni-PLS) in biological models of inflammatory processes. The characterization tests shown that sample refers to a heteropolysaccharide composed mainly of homogalacturonan and rhamnogalacturonan. This polysaccharide at dose of 10 mg/kg, when tested in our models of inflammation, showed significant activity in reducing carrageenan-induced paw oedema as well as all mediators edemas. This polysaccharide was able to inhibit the migration of leukocytes to the site of inflammation, and still reduced inflammatory nociception tests. This results, allows us to conclude that the polysaccharide extracted from Morinda citrifolia linn has anti-inflammatory potential since it reversed inflammatory parameters such as edema, leukocyte migration and nociception.

Riparin B, a Synthetic Compound Analogue of Riparin, Inhibits the Systemic Inflammatory Response and Oxidative Stress in Mice.

The aim of our study was to evaluate the anti-inflammatory, anti-nociceptive, and anti-oxidant action of Riparin B in vivo. We performed experiments in which we induced paw edema by carrageenan and other mediators, carrageenan-induced peritonitis and the level of myeloperoxidase (MPO) activity, pro-inflammatory cytokines (TNF-α and IL-1ß), malondialdehyde (MDA) acid, and glutathione (GSH) from the peritoneal fluid. We also performed behavior tests such as acetic acid-induced writhing, formalin-induced linking, and the hot plate test. Among the doses tested of the Riparin B (1, 3, and 10 mg/kg), the dose of 10 mg/kg showed the strongest effect, and this dose was able to reduce the paw edema induced by carrageenan, dextran, histamine serotonin, bradykinin, 48/80, and PGE2. Similarly, the Riparin B in the same dose reduced cell migration and significantly decreased the nociception induced by formalin and acetic acid and reversed the parameters of the oxidative stress. Thus, we can infer that Riparin B exhibits anti-inflammatory, anti-nociceptive, and anti-oxidant actions in vivo.

Gabapentin, a synthetic analogue of gamma aminobutyric acid, reverses systemic acute inflammation and oxidative stress in mice.

The aim of this study was to investigate the potential anti-inflammatory and anti-oxidant effects of gabapentin (GBP) in mice. The anti-inflammatory and anti-oxidant effects were evaluated using various mediators that induce paw edema, peritonitis model, myeloperoxidase (MPO) activity, proinflammatory cytokine levels, glutathione (GSH) consumption, and malondialdehyde (MDA) production in mice. Pretreatment of mice with GBP (1 mg/kg) significantly reduced carrageenan or dextran-induced paw edema (P<0.05) when compared to vehicle group. Adding to this, GBP (1 mg/kg) significantly inhibited paw edema induced by histamine, serotonin, bradikinin, 48/80 compound, and prostaglandin E2. In the carrageenan-induced peritonitis model, GBP significantly decreased total and differential leukocyte counts and reduced the levels of MPO activity in the plantar tissue and IL-1ß and TNF-α concentrations in the peritoneal exudate. The same dose of GBP also decreased the MDA concentration and increased the levels of GSH into the peritoneal fluid. In summary, our results demonstrated that GBP exhibited anti-inflammatory activity in mice by reducing the action of inflammatory mediators, neutrophil migration and proinflammatory cytokine levels, and anti-oxidant properties by decreasing the concentration of MDA and increasing the GSH content. These observations raise the possibility that GBP could be used to improve tissue resistance to damage during inflammatory conditions.