Nanoencapsulation of Curcuma longa L. extract for the treatment of experimental colitis

Inflammatory bowel diseases (IBDs) are gastrointestinal chronic inflammatory diseases characterized by chronic and recurrent intestinal ulcerations. Curcuminoids are naturally occurring polyphenolic compounds with remarkable bioactivity; however, their low water affinity and bioavailability usually hinder their application. Encapsulation techniques can be coupled with extraction procedures to yield nanoparticles that may have enhanced properties. In this work, curcuminoids were extracted from rhizomes of Curcuma longa L. and simultaneously encapsulated using ultrasound. The characterization of the curcuminoids nanoparticles showed that particles ranging from 124 +/- 81 to 252 +/- 68 nm were formed, and the main properties of the curcuminoids were maintained after encapsulation. Experimental colitis was induced in rats by 2,4,6-trinitrobenzene sulfonic acid, and they were subsequently treated with 10, 25, or 50 mg kg-1 of nanoencapsulated curcuminoids for 7 days through gavage, during which the disease activity index (DAI) was evaluated. Then the rats were euthanized, and the distal colon was removed for macroscopic analysis and the assessment of the activity of the enzymes myeloperoxidase and N-acetylglucosaminidase. The dose of 25 mg kg-1 of nanoencapsulated curcuminoids reduced the DAI and the activity of inflammatory enzymes compared to the untreated group and was established as the minimum effective dose to be used in the treatment of this model of experimental colitis in rats.