The mechanisms of the anti-inflammatory and anti-apoptotic effects of omega-3 polyunsaturated fatty acids during methotrexate-induced intestinal damage in cell line and in a rat model

Abstract

Background: The aim of this study was to examine the anti-inflammatory and anti-apop-totic patterns of omega-3 polyunsaturated fatty acids (n-3 PUFAs) during methotrexate (MTX) induced intestinal damage in cell culture and in a rat model. Methods: Non-treated and treated with MTX HT 29 and HCT116cells were exposed to increasing doses of n-3 PUFAs and cell viability was evaluated using PrestoBlue® assay. Male Sprague-Dawley rats were divided into 4 experimental groups: Control rats, CONTR+n-3PUFA rats that were treated with oral n-3PUFA, MTX rats were treated with MTX given IP, and MTX+n-3PUFA rats were treated with oral n-3PUFA before and following injection of MTX. Intestinal mucosal parameters and mucosal inflammation, enterocyte proliferation and apoptosis, TNF-α in mucosal tissue and plasma (ELISA), NF-κB, COX-2, TNF-α, Fas, FasL, Fadd, Bid, Bax and Bcl-2gene and protein levels were determined 72 h following MTX injection. Results: Exposure of HT 29 and HCT116cells to n-3 PUFA attenuated inhibiting effects of MTX on cell viability. MTX-n-3PUFA rats demonstrated a lower intestinal injury score and enhanced intestinal repair. A significant decrease in enterocyte apoptosis in MTX+n-3PUFA rats was accompanied by decreased TNF-α, FAS, FasL, FADD and BID mRNA levels. Decreased NF-κB, COX-2 and TNF-α levels in mucosa was accompanied by a decreased number of IELs and macro-phages. Conclusions: n-3PUFAs inhibit NF-κB/COX-2 induced production of pro-inflammatory cy-tokines and inhibit cell apoptosis mainly by extrinsic pathway in rats with MTX-induced intestinal damage.