Evaluation of iron transport from ferrous glycinate liposomes using Caco-2 cell model

Background: Iron fortification of foods is currently a strategy employed to fight iron deficiency in countries. Liposomes were assumed to be a potential carrier of iron supplements.Objective: The objective of this study was to investigate the iron transport from ferrous glycinate liposomes, and to estimate the effects of liposomal carriers, phytic acid, zinc and particle size on iron transport using Caco-2 cell models.Methods: Caco-2 cells were cultured and seeded in DMEM medium. Minimum essential medium was added to the basolateral side. Iron liposome suspensions were added to the apical side of the transwell.Results: The iron transport from ferrous glycinate liposomes was significantly higher than that from ferrous glycinate. In the presence of phytic acid or zinc ion, iron transport from ferrous glycinate liposomes and ferrous glycinate was evidently inhibited, and iron transport decreased with increasing phytic acid concentration. Iron transport was decreased with increase of particle size increasing of ferrous glycinate liposome.Conclusion: Liposomes could behave as more than a simple carrier, and iron transport from liposomes could be implemented via a mechanism different from the regulated non-heme iron pathway.Keywords: Ferrous glycinate liposomes, iron transport, phytic acid, particle siz

Evaluation of iron transport from ferrous glycinate liposomes using Caco-2 cell model.

Background: Iron fortification of foods is currently a strategy employed to fight iron deficiency in countries. Liposomes were assumed to be a potential carrier of iron supplements. Objective: The objective of this study was to investigate the iron transport from ferrous glycinate liposomes, and to estimate the effects of liposomal carriers, phytic acid, zinc and particle size on iron transport using Caco-2 cell models. Methods: Caco-2 cells were cultured and seeded in DMEM medium. Minimum essential medium was added to the basolateral side. Iron liposome suspensions were added to the apical side of the transwell. Results: The iron transport from ferrous glycinate liposomes was significantly higher than that from ferrous glycinate. In the presence of phytic acid or zinc ion, iron transport from ferrous glycinate liposomes and ferrous glycinate was evidently inhibited, and iron transport decreased with increasing phytic acid concentration. Iron transport was decreased with increase of particle size increasing of ferrous glycinate liposome. Conclusion: Liposomes could behave as more than a simple carrier, and iron transport from liposomes could be implemented via a mechanism different from the regulated non-heme iron pathway

Simple and Label-Free Fluorescent Detection of Melamine Based on Melamine–Thymine Recognition

In the past few years, melamine has been illegally added into dairy products to increase the apparent crude protein levels. If humans or animals drink the milk adulteration of melamine, it can form insoluble melamine–cyanurate crystals in their kidneys which causes kidney damage or even death. In the present work, we constructed a simple and label-free fluorescent method for melamine detection based on melamine-thymine recognition. SYBR Green I was utilized as a reporter for this method as it did not require any modification or expensive equipment. In the absence of melamine, polythymine DNA was digested by Exo I, which caused a decrease in the fluorescence signal. In the presence of melamine, the polythymine DNA was able to fold into a double chain structure, however this was done with the help of T-melamine-T mismatches to prevent degradation. Then, the SYBR Green I combined with the double-stranded DNA to result in an intense fluorescence signal. The limit of detection in this method was 1.58 μM, which satisfied the FDA standards. This method also had a good linear relationship within the range of 10–200 μM. In addition, this new method has a good selectivity to distinguish melamine from the component of milk. As a result, we developed a simple and highly selectivity method for melamine detection

Mechanistic Understanding of Tyrosinase Inhibition by Polymeric Proanthocyanidins from <i>Acacia confusa</i> Stem Bark and Their Effect on the Browning Resistance of Fresh-Cut Asparagus Lettuce

Tyrosinase inhibitors are capable of preventing unfavorable enzymatic browning of fruits and vegetables. In this study, the capacity of Acacia confusa stem bark proanthocyanidins (ASBPs) to inhibit tyrosinase activity was evaluated. ASBPs were shown to be a high-potential inhibitor of tyrosinase with IC50 values of 92.49 ± 4.70 and 61.74 ± 8.93 μg/mL when using L-tyrosine and L-DOPA as the substrate, respectively. The structural elucidation performed with UV-vis, FT-IR spectroscopy, ESI-MS and thiolysis coupled to HPLC-ESI-MS suggested that ASBPs had structural heterogeneity in monomer units and interflavan linkages and consisted mainly of procyanidins dominant with B-type linkages. To gain insights into the inhibitory mechanisms of ASBPs against tyrosinase, different spectroscopic and molecular docking methods were further conducted. Results validated that ASBPs possessed the ability to chelate copper ions and could prevent the oxidation process of substrates by tyrosinase. The hydrogen bond formed with Lys-376 residue played a key role in the binding force of ASBPs with tyrosinase that induced a certain alteration in the microenvironment and secondary structure of tyrosinase, resulting in the enzymatic activity being ultimately restricted. It was also observed that ASBPs treatment effectively inhibited the activities of PPO and POD to retard the surface browning of fresh-cut asparagus lettuce and thus extended their shelf-life. The results provided preliminary evidence supporting the exploitation of ASBPs into potential antibrowning agents for the fresh-cut food industry