Abstract: Objective To investigate the protective effects of magnolol against sepsis-induced inflammation and intestinal dysmotility. Methods Sepsis was induced by a single intraperitoneal injection of lipopolysaccharide(LPS). Male Wistar rats were randomly assigned to one of three treatment groups: magnolol before LPS injection(LPS/Mag group); vehicle before LPS injection(LPS/Veh group); and vehicle before injection of saline(Control/Veh) group. Intestinal transit and ex vivo circular intestinal muscle mechanical activity were assessed 12 h after LPS injection. Inducible nitric oxide synthase(iNOS) mRNA in rat intestine was studied by RT-PCR 2 h after LPS injection. In addition, antioxidant activity was determined by measuring malondialdehyde(MDA) concentration and superoxide dismutase(SOD) activity in the intestine 2 h after LPS injection. Nitrogen monoxide(NO) concentration in the intestine was also measured 12 h after LPS injection. Results Magnolol significantly increased the intestinal transit and circular muscle mechanical activity in LPS-treated animals. The iNOS mRNA expression in the small intestine were significantly reduced after magnolol treatment in LPS-induced septic animals. Moreover, magnolol significantly decreased MDA concentration and increased SOD activity in the rat intestine. Magnolol also significantly decreased NO concentration in the septic rat intestine 12 h after LPS injection. Conclusion Magnolol prevented sepsis-induced suppression of intestinal motility. The potential mechanism of this benefit of magnolol appears to be associated with blocking oxidative stress and decreasing the production of NO in the intestine.

Key words: sepsis, magnolol, lipopolysaccharide, nitrogen monoxidum