β-lactoglobulin micro- and nanostructures as bioactive compounds vehicle: In vitro studies

Abstract

Lactoglobulin (β-Lg) is known to be capable to bind hydrophilic and hydrophobic bioactive compounds. This research aimed to assess the in vitro performance of β-Lg micro-(diameter ranging from 200 to 300 nm) and nano (diameter < 100 nm) structures associated to hydrophilic and hydrophobic model compounds on Caco-2 cells and under simulated gastrointestinal (GI) conditions. Riboflavin and quercetin were studied as hydrophilic and hydrophobic model compounds, respectively. Cytotoxicity experiment was conducted using in vitro cellular model based on human colon carcinoma Caco-2 cells. Moreover, the digestion process was simulated using the harmonized INFOGEST in vitro digestion model, where samples were taken at each phase of digestion processoral, gastric and intestinal-and characterized in terms of particle size, polydispersity index (PDI), surface charge by dynamic light scattering (DLS); protein hydrolysis degree by 2,4,6-trinitrobenzene sulfonic acid (TNBSA) assay and native polyacrylamide gel electrophoresis; and bioactive compound concentration. Caco-2 cell viability was not affected up to 21 × 10 −3 mg mL −1 of riboflavin and 16 × 10 −3 mg mL −1 quercetin on β-Lg micro-and nanostructures. In the oral phase, β-Lg structures' particle size, PDI and surface charge values were not changed comparing to the initial β-Lg structures (i.e., before being subjected to in vitro GI digestion). During gastric digestion, β-Lg structures were resistant to proteolytic enzymes and to acid environment of the stomachconfirmed by TNBSA and native gel electrophoresis. In vitro digestion results indicated that β-Lg micro-and nanostructures protected both hydrophilic and hydrophobic compounds from gastric conditions and deliver them to target site (i.e., intestinal phase). In addition, β-Lg structures were capable to enhance riboflavin and quercetin bioaccessibility and bioavailability potential compared to bioactive compounds in their free form. This study indicated that β-Lg micro-and nanostructures were capable to enhance hydrophilic and hydrophobic compounds bioavailability potential and they can be used as oral delivery systems.

Evaluation of functional and nutritional potential of a protein concentrate from Pleurotus ostreatus mushroom

“…Subsequently, at the end of the intestinal phase, it was observed that HD reached 100% for the protein concentrate (p ≤ 0.05). Most probably, the proteolytic enzymes present in the pancreatin completely digested the proteins from the concentrate into smaller peptides (Simões, Martins, et al, 2020). The full digestion of proteins facilitates its absorption into the bloodstream.…”

Chemical Characterization of Sambucus nigra L. Flowers Aqueous Extract and Its Biological Implications

“…Control cells were grown with complete medium. The cellular viability was assessed using the Thiazolyl Blue Tetrazolium Bromide (MTT) reduction assay according to Simões et al [20]. MTT produces a yellowish solution that is converted to dark blue, water-insoluble MTT formazan by mitochondrial dehydrogenases of living cells.…”

Development and Characterization of Pleurotus ostreatus Mushroom—Wheat Bread

“…[54] After the bread samples passed from the oral to the gastric phase, the hydrolyzed starch remained similar, with no statistically significant differences between both phases (p >0.05). Conditions during the gastric phase were simulated to human physiological conditions, gastric conditions were similar to those described by Simões et al, [55] they were characterized by high ionic strength (values around 100 mmol L -1 ) and acidity (a pH value of 3) and these conditions inhibit the action of 𝛼-amylase and the hydrolysis of the starch was interrupted. In human digestion, the change in pH is gradual and enzymatic work continues, so that starch digestion continues even during the gastric phase, [54] in the protocol carried out for the simulation of digestion, the change in pH was immediate, so the digestion of the starch was interrupted during this phase.…”