Immune complex induced experimental colitis: beneficial effect of sulphasalazine in rabbits

Nuclear factor κB is a key transcription factor in the duodenal contractility alterations induced by lipopolysaccharide

Alterations in intestinal motility are one of the features of sepsis induced by lipopolysaccharide (LPS). This study investigated the role of the nuclear transcription factor κB (NF-κB) in the LPS-induced duodenal contractility alterations, generation of reactive oxygen species (ROS) and production of cytokines in rabbit duodenum. Rabbits were treated with saline, LPS, sulfasalazine + LPS, pyrrolidinedithiocarbamate (PDTC) + LPS or RO 106-9920 + LPS. Contractility studies were performed in an organ bath. The formation of products of oxidative damage to proteins (carbonyls) and lipids (malondialdehyde and 4-hydroxyalkenals) was quantified in intestinal tissue and plasma. The protein expression of NF-κB was measured by Western blot. The DNA binding activity of NF-κB was evaluated by transcription factor activity assay. The expression of interleukin-1β, tumour necrosis factor α (TNF-α), interleukin-6, interleukin-10 and interleukin-8 mRNA was determined by RT-PCR. Sulfasalazine, PDTC and RO 106-9920 blocked the inhibitory effect of LPS on contractions induced by ACh in the longitudinal smooth muscle of rabbit duodenum. Sulfasalazine, PDTC and RO 106-9920 reduced the increased levels of malondialdehyde and 4-hydroxyalkenals and the carbonyls induced by LPS in plasma. Lipopolysaccharide induced the activation, translocation to the nucleus and DNA binding of NF-κB. Lipopolysaccharide increased the mRNA expression of interleukin-6 and TNF-α in duodenal tissue, and this effect was partly reversed by PDTC, sulfasalazine and RO 106-9920. In conclusion, NF-κB mediates duodenal contractility disturbances, the generation of ROS and the increase in the expression of interleukin-6 and TNF-α induced by LPS. Sulfasalazine, PDTC and RO 106-9920 may be therapeutic drugs to reduce these effects.