目的:探究木兰醇对胰岛素抵抗的心肌细胞糖代谢的影响。方法:通过MTT法和LDH检测试剂盒检测木兰醇对心肌细胞的细胞毒性;100 n M的胰岛素刺激SD大鼠乳鼠心肌细胞24 h构建心肌胰岛素抵抗模型;葡萄糖检测试剂盒、糖摄取检测试剂盒检测心...目的:探究木兰醇对胰岛素抵抗的心肌细胞糖代谢的影响。方法:通过MTT法和LDH检测试剂盒检测木兰醇对心肌细胞的细胞毒性;100 n M的胰岛素刺激SD大鼠乳鼠心肌细胞24 h构建心肌胰岛素抵抗模型;葡萄糖检测试剂盒、糖摄取检测试剂盒检测心肌细胞的糖代谢情况;通过Western blot检测糖代谢相关信号通路蛋白磷酸化AKT的表达情况。结果:木兰醇对心肌细胞无明显毒性,且剂量依赖性的增加胰岛素敏感和非敏感型心肌细胞糖代谢。30μM的木兰醇孵育心肌细胞1 h,显著激活细胞磷酸化AKT信号通路。100 n M的胰岛素刺激心肌细胞24 h后,再次给予100 n M的胰岛素刺激后,心肌细胞的糖代谢水平无明显变化。30μM的木兰醇孵育心肌细胞24 h显著增加胰岛素抵抗心肌细胞的糖代谢水平。PI3K抑制剂Wortmanmin完全抑制木兰醇的上述作用。结论:木兰醇可通过激活AKT信号通路改善心肌细胞胰岛素抵抗。展开更多
AIM： To investigate the protective effects of magnolol on sepsis-induced inflammation and intestinal dysmotility. METHODS： Sepsis was induced by a single intraperitoneal injection of lipopolysaccharide （LPS）. Male...AIM： To investigate the protective effects of magnolol on 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 prior to LPS injection （LPS/Mag group）; vehicle prior to LPS injection （LPS/Veh group）; vehicle prior to injection of saline （Control/Veh）. Intestinal transit and circular muscle mechanical activity were assessed 12 h after LPS injection. Tumor necrosis factor-α （TNF-α）, interleukin-10 （IL-10）, monocyte chemoattractant protein-1 （MCP-1） and inducible nitric oxide synthase （iNOS） mRNA in rat ileum were studied by RT-PCR 2 h after LPS injection. Nuclear factor-κB （NF-κB） activity in the intestine was also investigated at this time using electrophoretic mobility shift assay. In addition, antioxidant activity was determined by measuring malondialdehyde （MDA） concentration and superoxide dismutase （SOD） activity in the intestine 2 h after LPS iniection.RESULTS： Magnolol significantly increased intestinal transit and circular muscle mechanical activity in LPS- treated animals. TNF-α, MCP-1 and iNOS mRNA expression in the small intestine were significantly reduced after magnolol treatment in LPS-induced septic animals, compared with untreated septic animals. Additionally,magnolol significantly increased IL-10 mRNA expression in septic rat ileum. Magnolol also significantly suppressed NF-κB activity in septic rat intestine. In addition, magnolol significantly decreased MDA concentration and increased SOD activity in rat ileum. CONCLUSION： Magnolol prevents sepsis-induced suppression of intestinal motility in rats. The potential mechanism of this benefit of magnolol appears to be modulation of self-amplified inflammatory events and block of oxidative stress in the intestine.展开更多
AIM： To study the effects of magnolol and honokiol on isolated smooth muscle of gastrointestinal tract and their relationship with Ca^2＋, and on the gastric emptying and the intestinal propulsive activity in mice.ME...AIM： To study the effects of magnolol and honokiol on isolated smooth muscle of gastrointestinal tract and their relationship with Ca^2＋, and on the gastric emptying and the intestinal propulsive activity in mice.METHODS： Routine experimental methods using isolated gastric fundus strips of rats and isolated ileum segments of guinea pigs were adopted to measure the smooth muscle tension, The effects of magnolol 10^-3, 10^-4, 10^-5 mol/L, and honokiol 10^-4, 10^-5, 10^-6 mol/L on the contractility of gastric fundus strips of rats and ileum of guinea pigs induced by acetylcholine （Ach） and 5-hydroxytryptamine （5-HT） was assessed respectively, The method using nuclein and pigment methylene blue was adopted to measure the gastric retention rate of nuclein and the intestinal propulsive ratio of a nutritional semi-solid meal for assessing the effect of magnolol and honokiol （0.5, 2, 20 mg/kg） on gastric emptying and intestinal propulsion.RESULTS： Magnolol and honokiol significantly inhibited the contractility of isolated gastric fundus strips of rats treated with Ach or 5-HT and isolated ileum guinea pigs treated with Ach or CaCl2, and both of them behaved as non-competitive muscarinic antagonists. Magnolol and honokiol inhibited the contraction induced by Ach in Ca^2＋-free medium and extracellular Ca^2＋-dependent contraction induced by Ach, Each group of magnolol and honokiol experiments significantly decreased the residual rate of nudein in the stomach and increased the intestinal propulsive ratio in mice.CONCLUSION： The inhibitory effect of magnolol and honokiol on contractility of the smooth muscles of isolated gastric fundus strips of rats and isolated ileum of guinea pigs is associated with a calcium-antagonistic effect. Magnolol and honokiol can improve the gastric emptying of a semi-solid meal and intestinal propulsive activity in mice.展开更多
文摘目的:探究木兰醇对胰岛素抵抗的心肌细胞糖代谢的影响。方法:通过MTT法和LDH检测试剂盒检测木兰醇对心肌细胞的细胞毒性;100 n M的胰岛素刺激SD大鼠乳鼠心肌细胞24 h构建心肌胰岛素抵抗模型;葡萄糖检测试剂盒、糖摄取检测试剂盒检测心肌细胞的糖代谢情况;通过Western blot检测糖代谢相关信号通路蛋白磷酸化AKT的表达情况。结果:木兰醇对心肌细胞无明显毒性,且剂量依赖性的增加胰岛素敏感和非敏感型心肌细胞糖代谢。30μM的木兰醇孵育心肌细胞1 h,显著激活细胞磷酸化AKT信号通路。100 n M的胰岛素刺激心肌细胞24 h后,再次给予100 n M的胰岛素刺激后,心肌细胞的糖代谢水平无明显变化。30μM的木兰醇孵育心肌细胞24 h显著增加胰岛素抵抗心肌细胞的糖代谢水平。PI3K抑制剂Wortmanmin完全抑制木兰醇的上述作用。结论:木兰醇可通过激活AKT信号通路改善心肌细胞胰岛素抵抗。
基金Supported by Beijing Municipal Science & Technology Commission Major Sci-tech Program, No. H020920050130
文摘AIM： To investigate the protective effects of magnolol on 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 prior to LPS injection （LPS/Mag group）; vehicle prior to LPS injection （LPS/Veh group）; vehicle prior to injection of saline （Control/Veh）. Intestinal transit and circular muscle mechanical activity were assessed 12 h after LPS injection. Tumor necrosis factor-α （TNF-α）, interleukin-10 （IL-10）, monocyte chemoattractant protein-1 （MCP-1） and inducible nitric oxide synthase （iNOS） mRNA in rat ileum were studied by RT-PCR 2 h after LPS injection. Nuclear factor-κB （NF-κB） activity in the intestine was also investigated at this time using electrophoretic mobility shift assay. In addition, antioxidant activity was determined by measuring malondialdehyde （MDA） concentration and superoxide dismutase （SOD） activity in the intestine 2 h after LPS iniection.RESULTS： Magnolol significantly increased intestinal transit and circular muscle mechanical activity in LPS- treated animals. TNF-α, MCP-1 and iNOS mRNA expression in the small intestine were significantly reduced after magnolol treatment in LPS-induced septic animals, compared with untreated septic animals. Additionally,magnolol significantly increased IL-10 mRNA expression in septic rat ileum. Magnolol also significantly suppressed NF-κB activity in septic rat intestine. In addition, magnolol significantly decreased MDA concentration and increased SOD activity in rat ileum. CONCLUSION： Magnolol prevents sepsis-induced suppression of intestinal motility in rats. The potential mechanism of this benefit of magnolol appears to be modulation of self-amplified inflammatory events and block of oxidative stress in the intestine.
基金Supported Dy the Natural Science Foundation of Liaoning Province,No. 20032074
文摘AIM： To study the effects of magnolol and honokiol on isolated smooth muscle of gastrointestinal tract and their relationship with Ca^2＋, and on the gastric emptying and the intestinal propulsive activity in mice.METHODS： Routine experimental methods using isolated gastric fundus strips of rats and isolated ileum segments of guinea pigs were adopted to measure the smooth muscle tension, The effects of magnolol 10^-3, 10^-4, 10^-5 mol/L, and honokiol 10^-4, 10^-5, 10^-6 mol/L on the contractility of gastric fundus strips of rats and ileum of guinea pigs induced by acetylcholine （Ach） and 5-hydroxytryptamine （5-HT） was assessed respectively, The method using nuclein and pigment methylene blue was adopted to measure the gastric retention rate of nuclein and the intestinal propulsive ratio of a nutritional semi-solid meal for assessing the effect of magnolol and honokiol （0.5, 2, 20 mg/kg） on gastric emptying and intestinal propulsion.RESULTS： Magnolol and honokiol significantly inhibited the contractility of isolated gastric fundus strips of rats treated with Ach or 5-HT and isolated ileum guinea pigs treated with Ach or CaCl2, and both of them behaved as non-competitive muscarinic antagonists. Magnolol and honokiol inhibited the contraction induced by Ach in Ca^2＋-free medium and extracellular Ca^2＋-dependent contraction induced by Ach, Each group of magnolol and honokiol experiments significantly decreased the residual rate of nudein in the stomach and increased the intestinal propulsive ratio in mice.CONCLUSION： The inhibitory effect of magnolol and honokiol on contractility of the smooth muscles of isolated gastric fundus strips of rats and isolated ileum of guinea pigs is associated with a calcium-antagonistic effect. Magnolol and honokiol can improve the gastric emptying of a semi-solid meal and intestinal propulsive activity in mice.
