Trends In Bioavailability Research Articles

Emerging Trends in Bioavailability and Pharma-Nutraceutical Potential of Whey Bioactives.

Whey, a component of milk and a useful by-product of the dairy industry's casein and cheese-making, has been used for generations to augment animal feed. It contains a range of proteins, including α-lactalbumin, β-lactoglobulin, bovine serum albumin, heavy and light chain immunoglobulins, lactoferrin, glycomacropeptide, and lactoperoxidase. Whey proteins exhibit great potential as biopolymers for creating bioactive delivery systems owing to their distinct health-enhancing characteristics and the presence of numerous amino acid groups within their structures. Whey has considerable factors such as antitumor, anti-inflammatory, antihypertensive, hypolipidemic, antiviral, and antibacterial properties in addition to chelating. The global market of whey protein stood at USD 5.33 billion in 2021, with a projected compound annual growth rate of 10.48% spanning the interval from 2022 to 2030. The escalating demand for whey protein is intrinsically linked to the amplifying consciousness surrounding healthy lifestyles. Notably, protein supplements are recurrently endorsed by fitness and sports establishments, thereby accentuating the focal point of customers toward whey protein. This review focuses on nutritional composition, whey bioactives, and their bioavailability with potential health benefits.

Soil Aggregates as a Source of Dissolved Organic Carbon to Streams: An Experimental Study on the Effect of Solution Chemistry on Water Extractable Carbon

Over the past two decades, headwater streams of the northern hemisphere have shown increased amounts of dissolved organic carbon (DOC), coinciding with decreased acid deposition. The exact nature of the mechanistic link between precipitation composition and stream water DOC is still widely debated in the literature. We hypothesize that soil aggregates are the main source of stream water DOC and that DOC release is greater in organic rich, riparian soils versus hillslope soils. To test these hypotheses, we collected soils from two main landscape positions (hillslope and riparian zones) from the acid-impacted Sleepers River Research Watershed in northeastern Vermont. We performed aqueous soil extracts with solutions of different ionic strength (IS) and composition to simulate changes in soil solution. We monitored dynamic changes in soil particle size, aggregate architecture and composition, leachate DOC concentrations, dissolved organic matter (DOM) characteristics with fluorescence spectroscopy and trends in bioavailability. In low IS solutions, extractable DOC concentrations were significantly higher, particle size (by laser diffraction) was significantly smaller and organic material was separated from mineral particles in scanning electron microscope observations. Furthermore, higher DOC concentrations were found in Na+ compared to Ca2+ solutions of the same IS. These effects are attributed to aggregate dispersion due to expanding diffuse double layers in decreased IS solutions and to decreased bridging by divalent cations. Landscape position impacted quality but not quantity of released DOC. Overall, these results indicate that soil aggregates might be one important link between Critical Zone inputs (i.e. precipitation) and exports in streams.

Impact of emerging, high-production-volume graphene-based materials on the bioavailability of benzo(a)pyrene to brine shrimp and fish liver cells.

With increasing commercialization of high volume, two-dimensional carbon nanomaterials comes a greater likelihood of environmental release. In aquatic environments, black carbon binds contaminants like aromatic hydrocarbons, leading to changes in their uptake, bioavailability, and toxicity. Engineered carbon nanomaterials can also adsorb pollutants onto their carbon surfaces, and nanomaterial physicochemical properties can influence this contaminant interaction. We used 2D graphene nanoplatelets and isometric carbon black nanoparticles to evaluate the influence of particle morphology and surface properties on adsorption and bioavailability of benzo(a)pyrene, a model aromatic hydrocarbon, to brine shrimp (Artemia franciscana) and a fish liver cell line (PLHC-1). Acellular adsorption studies show that while high surface area carbon black (P90) was most effective at a given concentration, 2D graphene nanoplatelets (G550) adsorbed more benzo(a)pyrene than carbon black with comparable surface area (M120). In both biological models, co-exposure to nanomaterials lead to reduced bioavailability, with G550 graphene nanoplatelets cause a greater reduction in bioavailability or response than the M120 carbon black nanoparticles. However, on a mass basis the high surface area P90 carbon black was most effective. The trends in bioavailability and adsorption were consistent across all biological and acellular studies, demonstrating the biological relevance of these results in different models of aquatic organisms. While adsorption is limited by surface area, 2D graphene nanoplatelets adsorb more benzo(a)pyrene than carbon black nanoparticles of similar surface area and charge, demonstrating that both surface area and shape play important roles in the adsorption and bioavailability of benzo(a)pyrene to carbon nanomaterials.

Metallothionein in liver of eels Anguilla anguilla from the Thames Estuary: an indicator of environmental quality?

The purpose of this study was to examine the role of the cysteine-rich protein metallothionein (MT) in the detoxification and metabolism of metals in livers of eels Anguilla anguilla from the Thames Estuary, and to assess the value of MT measurements in environmental monitoring. Hepatic MT levels and associated metal concentrations were determined in A. anguilla collected on three occasions during 1998 at sites along the tidal Thames (from freshwater to the sea) and also from a reference site (Tamar Estuary) in southwest England. MT was present at basal levels of 2 mg g −1 dry weight (dw), predominantly in association with the essential metals Cu and Zn. MT concentrations were variable within each eel ‘population’ but were generally highest (up to 11 mg g −1 in individual eels) at the more contaminated upper- and mid-estuarine sites in the Thames (e.g. Brentford and Kew). Lowest MT levels were those in eels from Blythe Sands at the mouth of the estuary. Season, sex, reproductive status and salinity may have influenced MT levels to some extent, although metals were the most significant factor. Hepatic MT concentrations were highly correlated with associated metal burdens (Zn, Cu, Ag and Cd),—notably reflecting Cu and Ag enrichment in the upper- and mid-estuary. With the exception of Zn, metals in the supernatant fraction of eel livers were primarily associated with MT. Proportions of Cu, Ag and Cd bound to MT increased as a function of accumulated metal burdens, with no indication of saturation. Thus, despite causing induction of MT, excess bioavailable Cu, Ag and Cd appear to be successfully detoxified in eels over the range of environmental contamination encountered along the Thames Estuary. Paradoxically, it may be argued from conventional doctrine that the presence of raised levels of MT, at upstream sites, constitutes a response to contamination and, by definition, signals that the fish are affected by metals; however, obvious signs of deleterious effects were not detected. Superficially, from liver MT data, it would seem that eel populations have become biochemically adapted to metal contamination. The approach tested here has proved viable in helping to interpret trends in bioavailability and the toxicological significance of accumulated metal burdens in Thames eels. A. anguilla is a common inhabitant of estuarine and fresh waters throughout Europe, and related species occur world wide. Therefore, determination of hepatic MT (and associated metals) in eels could be useful for monitoring responses to metal exposure and environmental quality on a much broader basis. Ideally these determinations should be performed in tandem with other sublethal-effects measurements to maximise information.

A simple method for the estimation of the bioavailability of radiocaesium from herbage contaminated by adherent soil

Adherent soil may contribute a large proportion of the radiocaesium content of sampled vegetation. Consequently, inadvertent ingestion of adherent soil can contribute significantly to the radiocaesium intake of grazing animals, and needs to be accounted for within radiological assessments. However, accurate estimation of the degree of soil adhesion on vegetation is acknowledged to be difficult. To determine the relative contributions of vegetation and soil to the radiocaesium contamination of milk and tissues, soil-specific estimation of radiocaesium bioavailability values would be required. Here we suggest that a previously developed in-vitro bioavailability assay (involving a 2 h extraction with 0.1 M stable CsCl) can be used to estimate the true absorption coefficient of radiocaesium associated with sampled vegetation directly. Using this technique, seasonal trends in bioavailability are demonstrated to vary in accordance with estimations of the degree of soil adherent to vegetation collected from an upland pasture. The use of this technique would negate the need for detailed measurements of the amount of soil adhering to sampled vegetation and soil-specific radiocaesium bioavailability assessments.