Ultrasound Alleviates Lipopolysaccharide-Induced Colonic Damage

Inflammatory bowel disease (IBD) is characterized by chronic inflammation in the intestinal tract. There is currently no effective cure for IBD. The aim of this study was to evaluate the protective effect of low-intensity pulsed ultrasound (LIPUS) on lipopolysaccharide (LPS)-induced intestinal damage in a C57BL/6 mouse model. Colonic inflammation was induced by LPS injection (0.75 mg/kg, i.p.) for 7 days. A 1.0 MHz ultrasound transducer was used with a duty cycle of 5% and a repetition frequency of 1 Hz. LIPUS was applied to the abdominal region for 15 min/day from days 1 to 6 at both intensity of 0.5 W/cm(2) or 1.0 W/cm(2). Colonic samples were collected for macroscopic and westerm blotting analysis. First, the optimal dose of LPS for experiments was investigated. Our results demonstrated that LIPUS alleviates colonic damage by reducing colon shortening and increasing the levels of tight junction proteins such as Occludin and ZO-1. These findings show that abdominal LIPUS stimulation may be a novel therapeutic strategy for IBD through enhancement of tight junction protein levels and attenuation of colonic length.