Comparative analysis of the effectiveness of local application of vitamin D3 and 5-aminosalicylic acid in experimental colitis

Abstract

Introduction. At the moment in the Russian Federation there are no dosage forms with vitamin D3, allowing effective delivery and local effect on the focus of inflammation and the damaged area of the large intestine in inflammatory bowel disease (IBD). Among such dosage forms rectal suppositories are of the greatest interest. The aim of the study was to carry out a comparative analysis of the effectiveness of local administration of vitamin D3 and 5-aminosalicylic acid in experimental colitis. Materials and methods. Experimental colitis (EC) was modeled with oxazolone solution. Suppositories with vitamin D3 and with 5-ASA were applied per rectum every 12 h. Clinical status (DAI), morphometry, colon tissue injury index (TDI), myeloperoxidase (MPO) and TNF-α expression in the lesion were assessed. Results. In EC, DAI is increases, an ulcerative defect is fixed in the lesion of the colon, TDI, neutrophils (NF), lymphocytes (LC), eosinophils (EF), histiocytes (HC), plasma cells (PC), fibroblasts (FB), MPO and TNF-α expression are increased. Vitamin D3 administration reduces DAI, ulcer defect, TDI, MPO and TNF-α expression, the number of NF, EF, LC and PCs, and increases the number of GCs and FBs. Comparison of vitamin D3 and 5-ASA administration revealed comparable efficacy against DAI. Morphometric evaluation of colorectal lesions showed that under the conditions of vitamin D3 administration, in contrast to 5-ASC, less infiltration, edema, signs of healing and repair of ulcerous defects were fixed earlier in EC; MPO expression increased on the 6th day, TNF-α expression on the 4th day. The TDI index on the 4th and 6th days of EC decreased equally under the conditions of vitamin D3 and 5-ASC application. Discussion. The reduction of clinical severity and morphological signs of damage in the large intestine wall at EC against the background of using rectal suppositories with vitamin D3 could be due to pleiotropic effects of vitamin D3. Conclusion. The effect of vitamin D3 in original rectal suppositories is comparable with local application of 5-ASC at EC, it reduces severity of clinical signs, representation of cells involved in tissue destruction, TNF-α and MPO expression in the colon wall and increases representation of cells mediating reparation.