Protective Effect of Naringin on In Vitro Gut-Vascular Barrier Disruption of Intestinal Microvascular Endothelial Cells Induced by TNF-

Naringin is a polymethoxylated flavonoid commonly found in citrus species and has therapeutic potential in intestinal disorders. However, the effect and mechanism of naringin on gut-vascular barrier disruption has not yet been reported. This study aimed to investigate the distinguishing and selectively protective effects of naringin on tumor necrosis factor (TNE)-alpha-induced gut-vascular barrier disruption and elucidate the potential mechanism. In the present study, an in vitro gut-vascular barrier model composed of rat intestinal microvascular endothelial cells (RIMVECs) was studied. Evans blue-albumin efflux assay showed that naringin (50 mu M) evidently protected the integrity of RIMVEC monolayer barriers against TNF-alpha-induced disruption. Naringin maintained the expression and distribution of tight junction proteins including zona occludin-1, occludin, claudin-1, and claudin-2. Additionally, naringin protected RIMVECs from TNF-alpha-induced apoptosis and cell migration suppression (41.1 +/- 2.2 vs 51.1 +/- 3.5%; 61.0 +/- 5.1 vs 72.2 +/- 6.2%). Our results indicate that naringin effectively ameliorates gut-vascular barrier disruption.