Nicotine inhibits cytokine synthesis by mouse colonic mucosa.

We examined the in vivo effect of nicotine on the synthesis of (pro)inflammatory mediators by mouse colonic mucosa. The synthesis of lipid mediators such as the prostanoids prostaglandin E2, 6-keto-prostaglandin F1 alpha and thromboxane B2, the 5-lipoxygenase products leukotriene B4 and leukotriene C4 and the platelet activating factor was not affected, whereas the synthesis of the pro-inflammatory cytokines interleukin-1 beta and tumor necrosis factor alpha was completely abolished. The beneficial effects of smoking and nicotine in ulcerative colitis could be attributed to this inhibition.