Treatment of colitis by oral negatively charged nanostructured curcumin in rats

Purpose: To examine the effects of a negatively charged nanostructured curcumin microemulsion in experimental ulcerative colitis (UC) in rats. Methods: Four percent acetic acid was used to induce UC. The animals were treated for seven days and randomly assigned to four groups: normal control (NC), colitis/normal saline (COL/NS), colitis/curcumin (COL/CUR), and colitis/mesalazine (COL/MES). The nanostructured curcumin was formulated with a negative zeta potential (-16.70 ± 1.66 mV). Dosage of the pro-inflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin 1-ß (IL-1ß), interleukin 6 (IL-6), and antioxidant enzymes (catalase, superoxide dismutase, and glutathione peroxidase), macro and microscopic evaluation of the colon tissue were analyzed. Results: The COL/CUR group had a higher level of antioxidant enzymes compared to the COL/MESgroup. The levels of TNF-α, IL-1ß and IL-6 were significantly lower in the colonic tissue of the COL/CUR group rats, when compared to the COL/NS and COL/MES groups (p < 0.001). The presence of ulcers in the colonic mucosa in rats of the COL/NSgroup was significantly higher than in the COL/MES group (p < 0.001). In the NC and COL/CUR groups, there were no ulcers in the colonic mucosa. Conclusions: The nanostructured microemulsion of curcumin, used orally, positively influenced the results of the treatment of UC in rats. The data also suggests that nanostructured curcumin with negative zeta potential is a promising phytopharmaceutical oral delivery system for UC therapy. Further research needs to be done to better understand the mechanisms of the negatively charged nanostructured curcumin microemulsion in UC therapy.

Evaluation of mesalazine polymeric conjugate in the treatment of actinic proctitis in rats

ABSTRACT Purpose: The present study aimed at testing a new formulation of mesalazine linked to chondroitin sulfate and its components alone in the treatment of actinic proctitis in rats. Methods: Forty-seven female Wistar rats were submitted to pelvic radiation and divided into eight groups: control A, mesalazine A, chondroitin A, and conjugate A, gavage of the according substance two weeks after irradiation and sacrifice three weeks after oral treatment; control C, mesalazine C, chondroitin C, and conjugate C, sacrifice six weeks after oral treatment. The rectum was submitted to histological characterization for each of the findings: inflammatory infiltrate, epithelial degeneration, mucosal necrosis, and fibrosis. Results: The inflammatory infiltrate was more intense in chondroitin A, mesalazine A, and conjugate C. The collagen deposition was less intense in chondroitin A, and mesalazine A, and more intense in control C. Conclusions: Mesalazine and chondroitin alone were efficacious in inducing a delayed inflammatory response, hence reducing the late fibrosis. The conjugate was able to induce an ever more delayed inflammatory response.

Enemas with mesalazine increase the tissue contents of mucins in the colonic mucosa devoid of fecal stream

Purpose: To evaluate the inflammatory reaction and measure the content of mucins, in the colonic mucosa without fecal stream submit to intervention with mesalazine. Methods: Twenty-four rats were submitted to a left colostomy and a distal mucous fistula and divided into two groups according to euthanasia to be performed two or four weeks. Each group was divided into two subgroups according daily application of enemas containing saline or mesalazine at 1.0 g/kg/day. Colitis was diagnosed by histological analysis and the inflammatory reaction by validated score. Acidic mucins and neutral mucins were determined with the alcian-blue and periodic acid of Schiff techniques, respectively. Sulfomucin and sialomucin were identified by high iron diamine-alcian blue technique. The tissue contents of mucins were quantified by computer-assisted image analysis. Mann-Whitney test was used to analyze the results establishing the level of significance of 5%. Results: Enemas with mesalazine in colonic segments without fecal stream decreased the inflammation score and increased the tissue content of all subtypes of mucins. The increase of tissue content of neutral, acid and sulfomucin was related to the time of intervention. Conclusion: Mesalazine enemas reduce the inflammatory process and preserve the content of mucins in colonic mucosa devoid of fecal stream.(AU)