中药结肠靶向给药研究

目的：考察中药制备结肠靶向给药的可能。方法：药物提取,精制后,制成微丸,选取经特殊处理果胶为包衣材料,氯化亚铵作为放射性内标物。结果：各项实验证明本制剂达到结肠靶向释药的设计要求。结论：为中药结肠靶向给药提供依据。     

Trimethylsilylation of Polygalacturonic Acid

The trimethylsilylation of polygalacturonic acid is investigated in formamide as reaction medium at elevated temperature employing 1,1,1,3,3,3‐hexamethyldisilazan (HMDS) or trimethylsilyl chloride (TMSCl) in combination with imidazole. The products obtained are characterized by size exclusion chromatography, NMR‐, and IR spectroscopy. Regarding the degree of substitution (DS), HMDS is a more reactive silylation reagent compared to TMSCl/imidazole. Products with DS values of 0.6 are obtained with TMSCl while HMDS yields products with DS of up to 1.8. Nevertheless, both reagents lead to the formation of side products. In the case of HMDS, formation of amid moiety occurs, which renders the carboxylic acid at the polymer backbone inaccessible for further transformations. Cross‐linking of polymer chains occurs applying TMSCl, which influences the molecular masses of the products obtained.     

DIETARY FIBER REDUCES β-CAROTENE UTILIZATION

High methoxyl pectins included at 7 percent of a chick diet reduced β-carotene utilization by over 50 percent.     

A matrix effect in pectin-rich fruits hampers digestion of allergen by pepsin in vivo and in vitro

BACKGROUND: It is a general belief that a food allergen should be stable to gastric digestion. Various acidic plant polysaccharides, including pectin, are ubiquitous in fruit matrixes and can form hydrogels under low-pH conditions. OBJECTIVE: The purpose of this study was to investigate the effect of hydrogel forming polysaccharide-rich fruit matrixes on in vivo gastric and in vitro pepsic digestion of fruit allergens. METHODS: Fruit extract proteins (kiwi, banana, apple and cherry) and a purified major kiwi allergen Act c 2 were digested with simulated gastric fluid in accordance with the US Pharmacopeia. In vivo experiments on kiwi fruit digestion were performed on four healthy non-atopic volunteers by examining the gastric content 1 h after ingestion of kiwi fruit. The Act c 2 and kiwi proteins were detected in immunoblots using monoclonal anti-Act c 2 antibodies and rabbit polyclonal antisera. RESULTS: Crude fruit extracts were resistant to digestion by pepsin when compared with commonly prepared extracts. In the gastric content of all volunteers, following kiwi fruit ingestion and immunoblotting, intact Act c 2 was detected with anti-Act c 2 monoclonal antibodies, while kiwi proteins of higher molecular weights were detected using rabbit polyclonal antisera. Addition of apple fruit pectin (1.5% and 3%) to the purified kiwi allergen was able to protect it from pepsin digestion in vitro. CONCLUSION: The matrix effect in pectin-rich fruits can influence the digestibility of food proteins and thereby the process of allergic sensitization in atopic individuals.     

艾司奥美拉唑镁肠溶片联合胶体果胶铋胶囊及阿莫西林胶囊在老年功能性消化不良患者中的应用及对营养状态、胰岛素样生长因子1的影响研究

目的:探讨艾司奥美拉唑镁肠溶片联合胶体果胶铋胶囊及阿莫西林胶囊在老年功能性消化不良(functional dyspepsia,FD)患者中的应用及对营养状态、胰岛素样生长因子1(IGF-1)的影响。方法:选取2015年1月至2019年1月应急总医院消化内科诊治的老年FD患者104例作为研究对象,以随机数字表法分为对照组(52例)和观察组(52例)。对照组患者采用艾司奥美拉唑镁肠溶片治疗,观察组患者在对照组的基础上联合胶体果胶铋胶囊及阿莫西林胶囊治疗。治疗15 d后对治疗效果进行评估;治疗后对患者进行6个月随访,比较两组患者近端胃功能参数、营养状态、胃动力学指标水平、不良反应发生情况及复发情况。结果:观察组患者治疗15 d后的近端胃功能参数(阈值饮水量、阈值近端胃容积、饱足饮水量和饱足近端胃容积)及IGF-1水平明显高于对照组,差异均有统计学意义(P<0.05);观察组患者治疗15 d后的餐后4、6 h胃排空率,血红蛋白、前白蛋白及白蛋白水平明显高于对照组,差异均有统计学意义(P<0.05)。两组患者血压波动、肝肾异常和头晕嗜睡等不良反应发生率及1个月复发率的差异均无统计学意义(P>0.05);观察组患者3、6个月复发率明显低于对照组,差异均有统计学意义(P<0.05)。结论:艾司奥美拉唑镁肠溶片联合胶体果胶铋胶囊及阿莫西林胶囊用于老年功能性消化不良患者,能提高患者胃功能及胃动力学水平,有助于改善其营养状态,未增加不良反应,且能降低治疗后复发率。     

Relating physicochemical properties of alginate-HMP complexes to their performance as drug delivery systems

This study aims to analyze the effect of physicochemical properties of alginate-high methoxyl pectin (HMP) complexes on their performance as drug delivery systems. Rheology, textural properties and swelling behavior of alginate-HMP complexes were determined. HMP alone showed weak gelling ability. As ratio of alginate increased, gel capability, hardness and adhesiveness of gels increased, but swelling rate decreased. Bovine serum albumin (BSA) was used as a model drug and entrapped in the alginate-HMP beads. Morphology of beads was correlated with adhesiveness. Drug loading content and encapsulation efficiency were related to electrostatic interactions between BSA and alginate-HMP complexes. Drug release profiles were correlated with both texture and swelling properties of alginate-HMP complexes and morphology of beads in simulated gastric fluids, while release in simulated intestinal fluids was affected by drug loading content. This study gives enlightenment that pre-selection of encapsulation materials may be achieved prior to encapsulation based on physicochemical properties of materials.     

Effect of Laurus nobilis L. oil,Nigella sativa L. oil and oleic acid on the antimicrobial and physical properties of subsistence agriculture: the case of cassava/pectin based edible films

Edible film is a packaging system that can eliminate or inhibit spoilage and pathogenic microorganisms, as carriers of antimicrobial compounds. It constitutes an approach for incorporating plant oils. In this study, antimicrobial activity, mechanical, barrier properties of cassava starch/pectin composite film have been studied by incorporating it with 1.5% of various types of oils (Laurus nobilis L. oil, Nigella sativa L. oil and oleic acid) as a natural antibacterial agent against pathogenic bacteria: Escherichia coli, Salmonella enteritidis, Staphylococcus aureus and Pseudomonas aeruginosa based on the clear inhibition zone exhibited which is evaluated in film. The suitable ratio of cassava starch/pectin at (1.5:1.5%w/v) has been used for film-forming solution throughout the experiment. Glycerol (1.5%v/w) is added to the blending compositions which act to maintain film integrity and to avoid pores and crack. Thickness and colour of films are affected (P<0.05) by the incorporated with various types of oils. The effects of various types of oils on the mechanical and barrier properties have been investigated. Tensile strength of the films is significantly decreased (P<0.05), while the elongation significantly increased, also the water vapour permeability and solubility in the water significantly decreased. The overall effect of novel L. nobilis L. oil followed by N. sativa L. oil is greater than oleic acid and control sample.     

Evaluation of the prebiotic effects of citrus pectin hydrolysate

Citrus pectin enzyme hydrolysate (PEH) of different hydrolysis time intervals (6 hours, PEH-6; 12 hours, PEH-12; 24 hours, PEH-24; or 48 hours, PEH-48) or concentrations (1%, 2%, and 4%) was tested for its growth stimulation effect on two probiotics, Bifidobacterium bifidum and Lactobacillus acidophilus. Higher monosaccharide concentrations and smaller molecular weights of PEHs were obtained by prolonging the hydrolysis time. In addition, higher PEH concentrations resulted in significantly higher (p < 0.05) probiotic populations, pH reduction, and increase in total titratable acidity than the glucose-free MRS negative control. Furthermore, significantly higher populations in the low pH environment and longer survival time in nonfat milk (p < 0.05) were observed when the two probiotics were incubated in media supplemented with 2% PEH-24, than in glucose and the negative control. In comparison with other prebiotics, addition of 2% PEH-24 resulted in a more significant increase in the probiotic population (p < 0.05) than in the commercial prebiotics. This study demonstrated that PEH derived from citrus pectin could be an effective prebiotic to enhance the growth, fermentation, acid tolerance, and survival in nonfat milk for the tested probiotics.     

Pectin as Rheology Modifier of a Gelatin-Based Biomaterial Ink

Gelatin is a natural biopolymer extensively used for tissue engineering applications due to its similarities to the native extracellular matrix. However, the rheological properties of gelatin formulations are not ideal for extrusion-based bioprinting. In this work, we present an approach to improve gelatin bioprinting performances by using pectin as a rheology modifier of gelatin and (3-glycidyloxypropyl)trimethoxysilane (GPTMS) as a gelatin–pectin crosslinking agent. The preparation of gelatin–pectin formulations is initially optimized to obtain homogenous gelatin–pectin gels. Since the use of GPTMS requires a drying step to induce the completion of the crosslinking reaction, microporous gelatin–pectin–GPTMS sponges are produced through freeze-drying, and the intrinsic properties of gelatin–pectin–GPTMS networks (e.g., porosity, pore size, degree of swelling, compressive modulus, and cell adhesion) are investigated. Subsequently, rheological investigations together with bioprinting assessments demonstrate the key role of pectin in increasing the viscosity and the yield stress of low viscous gelatin solutions. Water stable, three-dimensional, and self-supporting gelatin–pectin–GPTMS scaffolds with interconnected micro- and macroporosity are successfully obtained by combining extrusion-based bioprinting and freeze-drying. The proposed biofabrication approach does not require any additional temperature controller to further modulate the rheological properties of gelatin solutions and it could furthermore be extended to improve the bioprintability of other biopolymers.