Gastroprotective Effects of Inulae Flos on HCl/Ethanol-Induced Gastric Ulcers in Rats

Inulae Flos, the flower of Inula britannica L., is used as a dietary supplement, beverage, and medicine in East Asia. In this study, we evaluated the gastroprotective effects of Inulae Flos extract (IFE) against gastric mucosal lesions induced by hydrochloric acid (HCl)/ethanol in rats and explored its potential mechanisms by measuring antioxidant enzyme activity, mucus secretion, and prostaglandin E₂ (PGE₂) levels. Pretreatment with IFE at doses of 100 and 300 mg/kg significantly inhibited gastric lesions in HCl/ethanol-treated rats. IFE increased the activities of superoxide dismutase and catalase and the levels of glutathione and PGE₂ in gastric tissues. The administration of IFE also significantly increased the gastric wall mucus contents in HCl/ethanol-induced gastric lesions. These findings suggest that IFE has gastroprotective effects against HCl/ethanol-induced gastric lesions and exerts these effects through increased antioxidant levels and gastric mucus secretion. Inulae Flos may be a promising agent for the prevention and treatment of gastritis and gastric ulcers.     

Exploring Effects of Chitosan Oligosaccharides on the DSS-Induced Intestinal Barrier Impairment In Vitro and In Vivo

Intestinal barrier dysfunction is an essential pathological change in inflammatory bowel disease (IBD). The mucus layer and the intestinal epithelial tight junction act together to maintain barrier integrity. Studies showed that chitosan oligosaccharide (COS) had a positive effect on gut health, effectively protecting the intestinal barrier in IBD. However, these studies usually focused on its impact on the intestinal epithelial tight junction. The influence of COS on the intestinal mucus layer is still poorly understood. In this study, we explored the effect of COS on intestinal mucus in vitro using human colonic mucus-secreted HT-29 cells. COS relieved DSS (dextran sulfate sodium)-induced mucus defects. Additionally, the structural characteristics of COS greatly influenced this activity. Finally, we evaluated the protective effect of COS on intestinal barrier function in mice with DSS-induced colitis. The results indicated that COS could manipulate intestinal mucus production, which likely contributed to its intestinal protective effects.     

放置TCu200和TCu220宫内节育器后一年半内宫颈粘液中铜离子释放规律

用原子吸收法对使用Ｔ（Ｃｕ）２００和Ｔ（Ｃｕ）２２０型宫内节育器妇女的围排卵期宫颈粘液中铜离子浓度进行测定，以自身未带器前（Ｏ期）为对照。结果，带器者在第１，３，６，１２，１８个月宫颈粘液铜离子的平均浓度分别为；３．１８８，２．６９５，２．３２３，２．２４７，２．１１６μｇ／ｇ粘液湿重，与未带器前含铜量（０．８１８）相比，均有非常显著性差异（Ｐ＜０．０１），铜离子释放量随时间延长而逐渐减少。     

Metachronal propulsion of non-Newtonian viscoelastic mucus in an axisymmetric tube with ciliated walls

Cilia-induced flow of viscoelastic mucus through an idealized two-dimensional model of the human trachea is presented.The cilia motion is simulated by a metachronal wave pattern which enables the mobilization of highly viscous mucus even at nonzero Reynolds numbers.The viscoelastic mucus is analyzed with the upper convected Maxwell viscoelastic formulation which features a relaxation time and accurately captures normal stress generation in shear flows.The governing equations are transformed from fixed to wave(laboratory)frame with appropriate variables and resulting differential equations are perturbed about wave number.The trachea is treated as an axisymmetric ciliated tube.Radial and axial distributions in axial velocity are calculated via the regular perturbation method and pressure rise is computed with numerical integration using symbolic software MATHEMATICA^‘TM’.The influence of selected parameters which is cilia length,and Maxwell viscoelastic material parameter i.e.relaxation time for prescribed values of wave number are visualized graphically.Pressure rise is observed to increase considerably with elevation in both cilia length and relaxation time whereas the axial velocity is markedly decelerated.The simulations provide some insight into viscous-dominated cilia propulsion of rheological mucus and also serve as a benchmark for more advanced modeling.     

谷氨酸钠对大鼠胃粘膜细胞的保护作用

本文报道了谷氨酸钠对0.6N HCl所致的粘胃膜损伤的影响.0.6N HCl给饥饿大鼠灌胃,可引起严重的胃粘膜损伤,但提前15min以0.25g/kg和0.5g/kg谷氨酸钠溶液灌胃,再给予0.6NHCl,均可防止由盐酸所致的胃粘膜损伤。消炎痛提前60min皮下注射,可阻断谷氨酸钠的细胞保护作用,此外谷氨酸钠     

A thin film analog of the corneal mucus layer of the tear film: an enigmatic long range non-classical DLVO interaction in the breakup of thin polymer films

We present experimental results on the instability and dewetting of thin liquid polydimethylsiloxane (PDMS) films intercalated between an aqueous medium and a silicon wafer grafted with PDMS ‘brushes’. This is a thin film analog of the precorneal thin mucus coating sandwiched between the aqueous tear film and the glycocalyx carrying corneal epithelial surface. Lowering of the PDMS–water interfacial tension by a surfactant results in dewetting even of micrometer thick films within a few minutes. The instability appears to be induced by a long range non-classical DLVO force which has the same decay behavior as the nonretarded van der Waals force, but a magnitude which is about 2–3 orders higher. Implications for the breakup of the precorneal mucus layer and the tear film are discussed.     

生物黏液的润滑特性研究进展

生物黏液是广泛存在于自然界中动植物体内的一种胶黏物质,为多种成分的混合物,它在生物水基润滑体系中扮演了至关重要的角色.对于不同生物机体来说,黏液的不同组分和结构决定了其实现润滑作用的不同机理.本文作者分别从植物黏液、动物黏液和关节滑液3个方面综述了目前国内外关于生物黏液润滑特性的研究进展,并总结了当前研究中存在的问题和有待进一步探索的方向.这不仅对于探索摩擦和润滑的本质有着重要的意义,而且对于开发和研制绿色环保的生物水基润滑剂具有潜在的应用价值.     

Utilization of Sodium Nitroprusside as an Intestinal Permeation Enhancer for Lipophilic Drug Absorption Improvement in the Rat Proximal Intestine

As advanced synthetic technology has enabled drug candidate development with complex structure, resulting in low solubility and membrane permeability, the strategies to improve poorly absorbed drug bioavailability have attracted the attention of pharmaceutical companies. It has been demonstrated that nitric oxide (NO), a vital signaling molecule that plays an important role in various physiological systems, affects intestinal drug absorption. However, NO and its oxidants are directly toxic to the gastrointestinal tract, thereby limiting their potential clinical application as absorption enhancers. In this study, we show that sodium nitroprusside (SNP), an FDA-approved vasodilator, enhances the intestinal absorption of lipophilic drugs in the proximal parts of the small intestine in rats. The SNP pretreatment of the rat gastrointestinal sacs significantly increased griseofulvin and flurbiprofen permeation in the duodenum and jejunum but not in the ileum and colon. These SNP-related enhancement effects were attenuated by the co-pretreatment with dithiothreitol or c-PTIO, an NO scavenger. The permeation-enhancing effects were not observed in the case of antipyrine, theophylline, and propranolol in the duodenum and jejunum. Furthermore, the SNP treatment significantly increased acidic glycoprotein release from the mucosal layers specifically in the duodenum and jejunum but not in the ileum and colon. These results suggest that SNP increases lipophilic drug membrane permeability specifically in the proximal region of the small intestine through disruption of the mucosal layer.