Long‐chain fatty acid supplemented infant formula does not influence calcium and magnesium bioavailability in weanling rats

The influence of infant formula supplementation with long‐chain‐polyunsaturated fatty acids (LCPUFA) on calcium and magnesium bioavailability was assessed in rats. Two test diets containing a plain, unsupplemented (PF) or supplemented (SF) infant formula as the fat source and a control diet (C) were administered to weaning rats and food intake and body weight gain were monitored for 28 days. In order to assess calcium and magnesium bioavailability, during the last week faeces and urine were collected and apparent absorption and retention were calculated. Food intake and body weight showed no significant differences between PF and SF but were lower in both groups compared with C. Calcium and magnesium intake did not differ between PF and SF, although both parameters were lower compared with C. Calcium absorption efficiency in PF and SF was significantly higher than in C. However, both groups showed higher urinary calcium excretion and thus no differences were observed in calcium retention. Magnesium absorption efficiency was also significantly higher in PF and SF compared with C, but magnesium absorption was significantly lower in SF compared with PF and C. Nevertheless, urinary magnesium excretion and magnesium retention were similar in the three groups. The consumption of a diet containing an infant formula supplemented with LCPUFA compared with the plain formula does not affect calcium and magnesium bioavailability in rats. Copyright © 2005 Society of Chemical Industry     

PVP and surfactant combined carrier as an effective absorption enhancer of poorly soluble astilbin in vitro and in vivo

Context: Astilbin is considered to be a new and promising immunosuppressant for immune related diseases, but limited in clinical application due to its poor water solubility, difficult oral absorption and low bioavailability.

Objective: The present work studied the effect of PVP and surfactant combined carrier on its capability to improve drug absorption.

Materials and methods: PVP K30-Tween 80 combined carries was applied into the astilbin solid dispersions, tested both in vivo in beagle dogs and in vitro in transport experiments across Caco-2 cell monolayers.

Results and discussion: In the animal studies a many fold increase in plasma AUC was observed for the solid dispersions of drug in PVP K30-Tween 80 combined carries compared to active pharmaceutical ingredient (API). The applicability of Caco-2 monolayers as a tool for predicting the in vivo transport behavior of Astilbin in combination with a solubility enhancing carries was shown. In vitro transport studies confirmed the effect of combined carries on the absorption behavior of the astilbin. MTT studies showed the cell viability gradually decreased with the increase of the drug concentration in a dose dependent manner for astilbin and that in solid dispersions. The permeability and apparent permeability coefficients (P_app) increased with drug in the Caco-2 cell.

Conclusion: In this study, it was found that PVP K30 and Tween 80 promoted the permeability of drugs best within a certain amount. For astilbin PVP K30 and surfactant combined carrier had a strong potential to improve oral bioavailability.     

Enhancement of gastrointestinal absorption of isoliquiritigenin by nanostructured lipid carrier

Isoliquiritigenin (ISL) has various pharmacological effects. Our previous studies demonstrated that the oral bioavailability of ISL was low and the concentration-time profiles of ISL exhibited double peaks after oral administration in rat, but the underlying mechanisms remained unknown. The objective of this study was to clarify the gastrointestinal (GI) absorptive characteristics of ISL using in situ intestinal perfusion model as well as explain double peaks phenomenon after oral administration and to evaluate the potential of using nanostructured lipid carrier (NLC) as an oral delivery carrier for poorly water soluble drugs. The results showed that the absorption percent in the stomach for 2 h was less than 10%, the absorption process of intestine was first-order process with passive diffusion mechanism, and the main absorptive segment was colon. Isoliquiritigenin-loaded nanostructured lipid carrier (ISL-NLC) could enhance oral absorption of ISL. The reason for the Double Peak Phenomenon following oral administration in ISL plasma concentrations versus time profiles is Variability of Absorption within different regions of the gut, very low absorption from the stomach, jejunum, duodenum and ileum compared with the absorption from the colon. A pharmacokinetic study was conducted in rats after a single dose oral administration of ISL at 20 mg/kg in the form of either ISL-NLC or isoliquiritigenin solution (ISL-Sol). The AUC _(0∼∞) values were 5.43 ± 0.67 μg h mL⁻¹ and 29.60 ± 2.88 μg h mL⁻¹ after administration of the ISL-Sol and ISL-NLC, respectively. The relative bioavailability of ISL-NLC to isoliquiritigenin was 545%. Our studies provide evidence that NLC are valuable as an oral delivery carrier to enhance the absorption of a poorly water soluble drug, ISL.     

绿原酸磷脂复合物固体分散体的体外溶出和药动学研究

为研究绿原酸磷脂复合物固体分散体(CA-PC-SD)的体外溶出以及体内药动学规律,采用HPLC法考察CA-PC-SD的体外溶出,大鼠灌胃后测定其血药浓度,并采用DAS 2.0软件分析计算药动学参数.结果显示:CA-PC-SD显著改善绿原酸磷脂复合物(CA-PC)的溶出效果,相较于原料药(CA)其相对生物利用度提高2.12倍.表明CA-PC-SD能显著改善CA-PC的体外溶出特性以及CA的口服生物利用率.     

Assessment of lead bioaccessibility in peri-urban contaminated soils

Lead (Pb) bioaccessibility was assessed in a range of peri-urban soils (n=31) with differing sources of Pb contamination, including shooting range soils, and soils affected by incinerator, historical fill, mining/smelting, and gasworks activities. A gossan soil sample was also included. Lead bioaccessibility was determined using both gastric and intestinal phases of the SBRC in vitro assay and in vitro data was then incorporated into in vivo-in vitro regression equations to calculate Pb relative bioavailability. Lead bioaccessibility ranged from 26.8-105.2% to 5.5-102.6% for gastric and intestinal phase extractions respectively. Generally, Pb bioaccessibility was highest in the shooting range soils and lowest in the gossan soil. Predictions of relative Pb bioavailability derived from in vitro data were comparable for shooting ranges soils, but highly variable for the other soils examined. For incinerator, historical fill, gasworks and gossan soils, incorporating in vitro gastric data into the in vivo-in vitro regression equation resulting in more conservative Pb relative bioavailability values than those derived using the intestinal in vitro data.     

Research progress on the regulation of oxidative stress by phenolics: the role of gut microbiota and Nrf2 signaling pathway

In recent years, the increase in high-calorie diets and sedentary lifestyles has made obesity a global public health problem. An unbalanced diet promotes the production of proinflammatory cytokines and causes redox imbalance in the body. Phenolics have potent antioxidant activity and cytoprotective ability. They can scavenge free radicals and reactive oxygen species, and enhance the activity of antioxidant enzymes, thus combating the body's oxidative stress. They can also improve the body's inflammatory response, enhance the enzyme activity of lipid metabolism, and reduce the contents of cholesterol and triglyceride. Most phenolics are biotransformed and absorbed into the blood after the action by gut microbiota; these metabolites then undergo phase I and II metabolism and regulate oxidative stress by scavenging free radicals and increasing expression of antioxidant enzymes. Phenolics induce the expression of genes encoding antioxidant enzymes and phase II detoxification enzymes by stimulating Nrf2 to enter the nucleus and bind to the antioxidant response element after uncoupling from Keap1, thereby promoting the production of antioxidant enzymes and phase II detoxification enzymes. The absorption rate of phenolics in the small intestine is extremely low. Most phenolics reach the colon, where they interact with the microbiota and undergo a series of metabolism. Their metabolites will reach the liver via the portal vein and undergo conjugation reactions. Subsequently, the metabolites reach the whole body to exert biological activity by traveling with the systemic circulation. Phenolics can promote the growth of probiotics, reduce the ratio of Firmicutes/Bacteroidetes (F/B), and improve intestinal microecological imbalance. This paper reviews the nutritional value, bioactivity, and antioxidant mechanism of phenolics in the body, aiming to provide a scientific basis for the development and utilization of natural antioxidants and provide a reference for elucidating the mechanism of action of phenolics for regulating oxidative stress in the body. © 2023 Society of Chemical Industry.     

儿茶素类物质生物利用度研究进展

儿茶素类物质在自然界广泛存在,且具有多种生理功能,但其较低的生物利用度成为制约其开发利用的重要因素。本文对影响儿茶素类物质生物利用度的因素与提高儿茶素类物质生物利用度所采取的措施进行综述,以期为儿茶素类物质的进一步开发利用提供参考。     

酶法制备鸡血抗氧化肽及其抗氧化活性

为了评估鸡血用于膳食铁补充剂的潜力,本文以鸡血和氯化亚铁为原料制备了鸡血球肽螯合铁,采用扫描电镜及差示扫描量热对其结构进行表征,分析了其在不同温度（30~80 ℃）及pH（2~9）下的稳定性,并对其体外稳定性进行了探讨。结果表明鸡血球肽和铁结合生成一种新的肽铁螯合物。该螯合物具有良好的热稳定性（铁保留率73.76%以上）并耐酸碱。经体外模拟消化发现,鸡血球肽螯合铁的消化稳定性（铁保留率为86.01%）优于硫酸亚铁和葡萄糖酸亚铁。此外,在1%植酸、1%草酸和8%膳食纤维这三种膳食因素的影响下,鸡血球肽螯合铁显示出比硫酸亚铁和葡萄糖酸亚铁更好的生物可及性。     

类胡萝卜素肠道吸收及生物利用度研究进展

类胡萝卜素是一种自然界中分布广泛的食品成分,具有多种生物学活性,受到诸多学者关注。文章主要从类胡萝卜素生物学功能、食品成分对类胡萝卜素吸收利用的影响及提高其生物学利用三方面综述其研究进展。类胡萝卜素具有特异性调控相关基因及蛋白的功能,进而具有多种生物活性。文章从机制的角度归纳总结类胡萝卜素的功能特性,整理了食品成分间相互作用对类胡萝卜素生物利用率的影响,总结了纳米载药系统技术、异构化处理技术以及通过食品加工方式三种提高类胡萝卜素生物利用率的方法,为类胡萝卜素功能性产品研发提供一定的理论参考。