Physicochemical properties of wild and cultivated Saccharina latissima macroalgae harvested in the Canadian boreal-subarctic transition zone

Saccharina latissima is a brown seaweed used as a food ingredient. The aim of this work was to study possible differences between S. latissima chemical composition, color, mode of cultivation, harvesting period and site and its environmental conditions. Water temperature, salinity, radiation, and fluorescence were monitored in each harvesting site. Chemical composition of S. latissima varied greatly with period and site, with a high content of carbohydrates and ash. Crude protein content varied from 3.7 % to 12.8 %, with a higher concentration observed in wild samples harvested in Bas-St. Laurent (11.1-12.8 %). Cultivated seaweed also presented a high crude protein (12.2 %) and ash (52 % against 27 % in wild samples) concentrations, but crude fiber and carbohydrates concentrations were lower, reaching up to 2.7 and 1.9-fold, respectively, than those in wild seaweeds. S. latissima presented a more intense yellow color in June. A trend of darker and more green-colored seaweeds when cultivated in the end of summer was confirmed. Our results suggest that variations in chemical components and chromaticity of this species are probably affected by complex interactions of environmental conditions.

Assessing the Activity under Different Physico-Chemical Conditions, Digestibility, and Innocuity of a GAPDH-Related Fish Antimicrobial Peptide and Analogs Thereof

The antimicrobial activity of SJGAP (skipjack tuna GAPDH-related antimicrobial peptide) and four chemical analogs thereof was determined under different physicochemical conditions, including different pH values, the presence of monovalent and divalent cations, and after a heating treatment. The toxicity of these five peptides was also studied with hemolytic activity assays, while their stability under human gastrointestinal conditions was evaluated using a dynamic in vitro digestion model and chromatographic and mass spectrometric analyses. The antibacterial activity of all analogs was found to be inhibited by the presence of divalent cations, while monovalent cations had a much less pronounced impact, even promoting the activity of the native SJGAP. The peptides were also more active at acidic pH values, but they did not all show the same stability following a heat treatment. SJGAP and its analogs did not show significant hemolytic activity (except for one of the analogs at a concentration equivalent to 64 times that of its minimum inhibitory concentration), and the two analogs whose digestibility was studied degraded very rapidly once they entered the stomach compartment of the digestion model. This study highlights for the first time the characteristics of antimicrobial peptides from Scombridae or homologous to GAPDH that are directly related to their potential clinical or food applications.

Impact of Harvest Month and Drying Process on the Nutritional and Bioactive Properties of Wild Palmaria palmata from Atlantic Canada

The macroalga Palmaria palmata could be a sustainable and nutritional food resource. However, its composition may vary according to its environment and to processing methods used. To investigate these variations, wild P. palmata from Quebec were harvested in October 2019 and June 2020, and dried (40 °C, ≃5 h) or stored as frozen controls (-80 °C). The chemical (lipids, proteins, ash, carbohydrates, fibers), mineral (I, K, Na, Ca, Mg, Fe), potential bioactive compound (carotenoids, polyphenols, β-carotene, α-tocopherol) compositions, and the in vitro antioxidant activity and angiotensin-converting enzyme (ACE) inhibition potential of water-soluble extracts were determined. The results suggested a more favorable macroalgae composition in June with a higher content of most nutrients, minerals, and bioactive compounds. October specimens were richer only in carbohydrates and carotenoids. No significant differences in antioxidant or anti-ACE inhibitory activities were found between the two harvest months. The drying process did not significantly impact the chemical and mineral compositions, resulting in only small variations. However, drying had negative impacts on polyphenols and anti-ACE activities in June, and on carotenoids in October. In addition, a concentration effect was observed for carotenoids, β-carotene and α-tocopherol in June. To provide macroalgae of the highest nutritional quality, the drying process for June specimens should be selected.

Modern Tools for Modern Brachytherapy

This review aims to showcase the brachytherapy tools and technologies that have emerged during the last 10 years. Soft-tissue contrast using magnetic resonance and ultrasound imaging has seen enormous growth in use to plan all forms of brachytherapy. The era of image-guided brachytherapy has encouraged the development of advanced applicators and given rise to the growth of individualised 3D printing to achieve reproducible and predictable implants. These advances increase the quality of implants to better direct radiation to target volumes while sparing normal tissue. Applicator reconstruction has moved beyond manual digitising, to drag and drop of three-dimensional applicator models with embedded pre-defined source pathways, ready for auto-recognition and automation. The simplified TG-43 dose calculation formalism directly linked to reference air kerma rate of high-energy sources in the medium water remains clinically robust. Model-based dose calculation algorithms accounting for tissue heterogeneity and applicator material will advance the field of brachytherapy dosimetry to become more clinically accurate. Improved dose-optimising toolkits contribute to the real-time and adaptive planning portfolio that harmonises and expedites the entire image-guided brachytherapy process. Traditional planning strategies remain relevant to validate emerging technologies and should continue to be incorporated in practice, particularly for cervical cancer. Overall, technological developments need commissioning and validation to make the best use of the advanced features by understanding their strengths and limitations. Brachytherapy has become high-tech and modern by respecting tradition and remaining accessible to all.

Comparison of four-year toxicities and local control of ultra-hypofractionated vs moderate-hypofractionated image guided prostate radiation with HDR brachytherapy boost: A phase I-II single institution trial

Purpose/Objectives

To analyze the long term efficacy and safety of an ultra-hypofractionated (UHF) radiation therapy prostate treatment regimen with HDR brachytherapy boost (BB) and compare it to moderate-hypofractionated regimens (MHF).

Materials/Methods

In this single arm, prospective monocentric study, 28 patients with intermediate risk prostate cancer were recruited in an experimental treatment arm of 25 Gy in 5 fractions plus a 15 Gy HDR BB. They were then compared to two historical control groups, treated with either 36 Gy in 12 fractions or 37.5 Gy in 15 fractions with a similar HDR BB. The control groups included 151 and 311 patients respectively. Patient outcomes were reported using the International Prostate Symptom Score (IPSS) and Expanded Prostate Index Composite (EPIC-26) questionnaires at baseline and at each follow-up visit.

Results

Median follow-up for the experimental arm was 48.5 months compared to 47 months and 60 months compared to the 36/12 and 37,5/15 groups respectively. The IPSS and EPIC scores did not demonstrate any significant differences in the gastrointestinal or genitourinary domains between the three groups over time. No biochemical recurrence occurred in the UHF arm as defined by the Phoenix criterion.

Conclusion

The UHF treatment scheme with HDR BB seems equivalent to standard treatment arms in terms of toxicities and local control. Randomized control trials with larger cohorts are ongoing and needed to further confirm our findings.

Variation of the Nutritional Composition and Bioactive Potential in Edible Macroalga Saccharina latissima Cultivated from Atlantic Canada Subjected to Different Growth and Processing Conditions

Macroalgae are a new food source in the Western world. The purpose of this study was to evaluate the impact of harvest months and food processing on cultivated Saccharina latissima (S. latissima) from Quebec. Seaweeds were harvested in May and June 2019 and processed by blanching, steaming, and drying with a frozen control condition. The chemical (lipids, proteins, ash, carbohydrates, fibers) and mineral (I, K, Na, Ca, Mg, Fe) compositions, the potential bioactive compounds (alginates, fucoidans, laminarans, carotenoids, polyphenols) and in vitro antioxidant potential were investigated. The results showed that May specimens were significantly the richest in proteins, ash, I, Fe, and carotenoids, while June macroalgae contained more carbohydrates. The antioxidant potential of water-soluble extracts (Oxygen Radical Absorbance Capacity [ORAC] analysis-625 µg/mL) showed the highest potential in June samples. Interactions between harvested months and processing were demonstrated. The drying process applied in May specimens appeared to preserve more S. latissima quality, whereas blanching and steaming resulted in a leaching of minerals. Losses of carotenoids and polyphenols were observed with heating treatments. Water-soluble extracts of dried May samples showed the highest antioxidant potential (ORAC analysis) compared to other methods. Thus, the drying process used to treat S. latissima harvested in May seems to be the best that should be selected.

In Vitro Bioaccessibility of Proteins and Bioactive Compounds of Wild and Cultivated Seaweeds from the Gulf of Saint Lawrence

Despite the increased interest in macroalgae protein and fibers, little information is available on their bioaccessibility. The application of an in vitro gastrointestinal digestion model to study the degree of disintegration and release of proteins with expressed bioactivities from wild and cultivated Palmaria palmata and Saccharina latissima was proposed in this study. Macroalgae from the Gulf of St Lawrence, Canada, were submitted to digestive transit times of 2 (oral), 60 (gastric) and 120 (duodenal) minutes. Among wild samples, P. palmata had a higher percentage of disintegration, protein release and degree of hydrolysis than S. latissima. While the least digested sample, wild S. latissima, was the sample with the highest antioxidant activity (210 μmol TE g-1), the most digested sample, cultivated P. palmata, presented the highest ability to inhibit the angiotensin-converting enzyme (ACE), reaching 32.6 ± 1.2% at 3 mg mL-1. ACE inhibitory activity increased from 1 to 3 mg mL-1, but not at 5 mg mL-1. Wild samples from both species showed an ACE inhibition around 27.5%. Data suggested that the disintegration of the samples was influenced by their soluble and insoluble fiber contents. Further information on the bioaccessibility and bioactivity of these macroalgae should consider the characterization of digestion products other than protein, as well as the effects of previous product processing.

Focal HDR brachytherapy boost to stereotactic radiotherapy (fBTsRT) for prostate cancer: a phase II randomized controlled trial

BACKGROUND

For patients with a higher burden of localized prostate cancer, radiation dose escalation with brachytherapy boosts have improved cancer control outcomes at the cost of urinary toxicity. We hypothesize that a focal approach to brachytherapy boosts targeting only grossly visualized tumor volumes (GTV) combined with stereotactic radiotherapy will improve quality of life (QoL) outcomes without compromising cancer control.

METHODS

150 patients with intermediate or high-risk prostate cancer will be enrolled and randomized 1:1 in a cohort multiple randomized clinical trial phase 2 design. Patients are eligible if planned for standard-of-care (SOC) high dose rate (HDR) brachytherapy boost to radiotherapy (RT) with GTVs encompassing < 50% of the prostate gland. Those randomly selected will be offered the experimental treatment, consisting of focal HDR brachytherapy boost (fBT) of 13-15 Gy in 1 fraction followed by stereotactic radiotherapy (sRT) 36.25-40 Gy in 5 fractions to the prostate (+/- 25 Gy to the elective pelvis) delivered every other day. The primary endpoint is to determine if fBTsRT is superior to SOC by having fewer patients experience a minimally important decline (MID) in urinary function as measured by EPIC-26 at 1 and 2 years. Secondary endpoints include rates of toxicity measured by Common Terminology Criteria for Adverse Events (CTCAE), and failure-free survival outcomes.

DISCUSSION

This study will determine whether a novel approach for the treatment of localized prostate cancer, fBTsRT, improves QoL and merits further evaluation. Trial registration This trial was prospectively registered in ClinicalTrials.gov as NCT04100174 as a companion to registry NCT03378856 on September 24, 2019.

Identification of Gastrointestinal Digestion Stable Antihypertensive Fish Peptides from Atlantic Mackerel (Scomber scombrus)

High blood pressure has been recognized as one of the main risk factors of cardiometabolic syndrome by health organizations. Hypertension is medicated by various classes of synthetic drugs; however, adverse effects have repeatedly been reported. Moreover, natural alternatives such as fish peptides have been effective in the treatment and prevention of hypertension. The aim of our study was to fractionate and identify antihypertensive peptides. Fractions were produced using different techniques of solid-phase extraction (SPE), pressure-driven ultrafiltration (UF), and electro04dialysis with UF membrane. According to our results, the hydrophobic fraction of SPE (IC₅₀ 5 μg) was the most potent anti-angiotensin converting enzyme (ACE) product. Findings of the study suggest that the separation technique plays an important role in the isolation efficiency of antihypertensive biopeptides. Importantly, the hydrophobic fraction's activity was retained through a static model of an in vitro gastrointestinal digestion system. In conclusion, polarity regardless of charge and size was the most important factor for anti-ACE activity of an Atlantic mackerel biopeptide. In addition, the presence of leucine at either of the extremities (C- or N-terminal) and/or leucine-rich motifs could well explain the hypotensive effect of our active fraction.

On the use of polychromatic cameras for high spatial resolution spectral dose measurements

Objective. Despite the demonstrated benefits of hyperspectral formalism for stem effect corrections in the context of fiber dose measurements, this approach has not been yet translated into volumetric measurements where cameras are typically used for their distinguishing spatial resolution. This work investigates demosaicing algorithms for polychromatic cameras based spectral imaging. Approach. The scintillation and Cherenkov signals produced in a radioluminescent phantom are imaged by a polychromatic camera and isolated using the spectral formalism. To do so, five demosaicing algorithms are investigated from calibration to measurements: a clustering method and four interpolation algorithms. The resulting accuracy of scintillation and Cherenkov images is evaluated with measurements of the differences (mean ± standard deviation) between the obtained and expected signals from profiles drawn across a scintillation spot. Signal-to-noise ratio and signal-to-background ratio are further measured and compared in the resulting scintillation images. Finally, the resulting differences on the scintillation signal from a 0.2 × 0.2 cm2 region-of-interest (ROI) were reported. Main results. Clustering, OpenCV, bilinear, Malvar and Menon demosaicing algorithms respectively yielded differences of 3 ± 5%, 1 ± 3%, 1 ± 3%, 1 ± 2% and 2 ± 4% in the resulting scintillation images. For the Cherenkov images, all algorithms provided differences below 1%. All methods enabled measurements over the detectability (SBR > 2) and sensitivity (SNR > 5) thresholds with the bilinear algorithm providing the best SNR value. Clustering, OpenCV, bilinear, Malvar and Menon demosaicing algorithms respectively provided differences on the ROI analysis of 7 ± 5%, 3 ± 2%, 3 ± 2%, 4 ± 2%, 7 ± 3%. Significance. Radioluminescent signals can accurately be isolated using a single polychromatic camera. Moreover, demosaicing using a bilinear kernel provided the best results and enabled Cherenkov signal subtraction while preserving the full spatial resolution of the camera.

Beneficial effects of fish and fish peptides on main metabolic syndrome associated risk factors: Diabetes, obesity and lipemia

The definition of metabolic syndrome (MetS) fairly varies from one to another guideline and health organization. Per description of world health organization, occurrence of hyperinsulinemia or hyperglycemia in addition to two or more factors of dyslipidemia, hypoalphalipoproteinemia, hypertension and or large waist circumference factors would be defined as MetS. Conventional therapies and drugs, commonly with adverse effects, are used to treat these conditions and diseases. Nonetheless, in the recent decades scientific community has focused on the discovery of natural compounds to diminish the side effects of these medications. Among many available bioactives, biologically active peptides have notable beneficial effects on the management of diabetes, obesity, hypercholesterolemia, and hypertension. Marine inclusive of fish peptides have exerted significant bioactivities in different experimental in-vitro, in-vivo and clinical settings. This review exclusively focuses on studies from the recent decade investigating hypoglycemic, hypolipidemic, hypercholesterolemic and anti-obesogenic fish and fish peptides. Related extraction, isolation, and purification methodologies of anti-MetS fish biopeptides are reviewed herein for comparison purposes only. Moreover, performance of biopeptides in simulated gastrointestinal environment and structure-activity relationship along with absorption, distribution, metabolism, and excretion properties of selected oligopeptides have been discussed, in brief, to broaden the knowledge of readers on the design and discovery trends of anti-MetS compounds.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2022.2052261 .

Determination of the Relationships between the Chemical Structure and Antimicrobial Activity of a GAPDH-Related Fish Antimicrobial Peptide and Analogs Thereof

The structure–activity relationships and mode of action of synthesized glyceraldehyde-3-phosphate dehydrogenase (GAPDH)-related antimicrobial peptides were investigated. Including the native skipjack tuna GAPDH-related peptide (SJGAP) of 32 amino acid residues (model for the study), 8 different peptide analogs were designed and synthesized to study the impact of net charge, hydrophobicity, amphipathicity, and secondary structure on both antibacterial and antifungal activities. A net positive charge increase, by the substitution of anionic residues or C-terminal amidation, improved the antimicrobial activity of the SJGAP analogs (minimal inhibitory concentrations of 16–64 μg/mL), whereas the alpha helix content, as determined by circular dichroism, did not have a very definite impact. The hydrophobicity of the peptides was also found to be important, especially for the improvement of antifungal activity. Membrane permeabilization assays showed that the active peptides induced significant cytoplasmic membrane permeabilization in the bacteria and yeast tested, but that this permeabilization did not cause leakage of 260 nm-absorbing intracellular material. This points to a mixed mode of action involving both membrane pore formation and targeting of intracellular components. This study is the first to highlight the links between the physicochemical properties, secondary structure, antimicrobial activity, and mechanism of action of antimicrobial peptides from scombrids or homologous to GAPDH.

Algae as a Source of Natural Flavors in Innovative Foods

As a result of their nutritive values, algae have been used as a food resource for centuries, and there is a growing interest to use them as enrichment ingredients in food products. However, food product acceptance by consumers is strongly linked to their organoleptic properties, especially the aroma, taste, and a combination of the two, flavor. With regard to edible algae, "fresh seashore", "seafood-like", "cucumber green", and "earthy" are descriptors commonly used to define their aromas. Several families of molecules participate in the diversity and peculiarities of algal aromas: pungent sulfur compounds and marine halogenated components but also herbaceous fatty acid derivatives and fruity-floral terpenoids. In both macroalgae (seaweeds) and microalgae, these compounds are studied from a chemistry point of view (identification and quantification) and a sensorial point of view, involving sensorial evaluation by panelists. As a whole food, a food ingredient, or a feed, algae are valued for their nutritional composition and their health benefits. However, because the acceptance of food by consumers is so strongly linked to its sensorial features, studies have been performed to explore the aromas of algae, their impact on food, their evolution through processing, and their ability to produce selected aromas using biotechnology. This review aims at highlighting algal aromas from seaweed and microalgae as well as their use, their handling, and their processing in the food industry.

Deformable scintillation dosimeter: II. Real-time simultaneous measurements of dose and tracking of deformation vector fields

Anatomical motion and deformation pose challenges to the understanding of the delivered dose distribution during radiotherapy treatments. Hence, deformable image registration (DIR) algorithms are increasingly used to map contours and dose distributions from one image set to another. However, the lack of validation tools slows their clinical adoption, despite their commercial availability. This work presents a novel water-equivalent deformable dosimeter that simultaneously measures the dose distribution and tracks deformation vector fields (DVF). The dosimeter in made of an array of 19 scintillating fiber detectors embedded in a cylindrical elastomer matrix. It is imaged by two pairs of stereoscopic cameras tracking the position and angulation of the scintillators, while measuring the dose. The resulting system provides a precision of 0.3 mm on DVF measurements. The dosimeter was irradiated with 5 × 3, 4 × 3 and 3 × 3 cm²6 MV photon beams in both fixed and deformed conditions. The measured DVF was compared to the one computed with a DIR algorithm (Plastimatch). The deviations between the computed and measured DVFs was below 1.5 mm. As for dose measurements, the dosimeter acquired the dose distribution in fixed and deformed conditions within 1% of the treatment planning system calculation and complementary dose validation using the Hyperscint dosimetry system. Using the demonstrated qualities of scintillating detectors, we developed a real-time, water-equivalent deformable dosimeter. Given it's sensor tracking position precision and dose measurements accuracy, the developed detector is a promising tools for the validation of DIR algorithms as well as dose distribution measurements under fixed and deformed conditions.

Deformable scintillation dosimeter I: challenges and implementation using computer vision techniques

Plastic scintillation detectors are increasingly used to measure dose distributions in the context of radiotherapy treatments. Their water-equivalence, real-time response and high spatial resolution distinguish them from traditional detectors, especially in complex irradiation geometries. Their range of applications could be further extended by embedding scintillators in a deformable matrix mimicking anatomical changes. In this work, we characterized signal variations arising from the translation and rotation of scintillating fibers with respect to a camera. Corrections are proposed using stereo vision techniques and two sCMOS complementing a CCD camera. The study was extended to the case of a prototype real-time deformable dosimeter comprising an array of 19 scintillating fibers. The signal to angle relationship follows a gaussian distribution (FWHM = 52°) whereas the intensity variation from radial displacement follows the inverse square law. Tracking the position and angle of the fibers enabled the correction of these spatial dependencies. The detecting system provides an accuracy and precision of respectively 0.08 mm and 0.3 mm on the position detection. This resulted in an uncertainty of 2° on the angle measurement. Displacing the dosimeter by ±3 cm in depth resulted in relative intensities of 100 ± 10% (mean ± standard deviation) to the reference position. Applying corrections reduced the variations thus resulting in relative intensities of 100 ± 1%. Similarly, for lateral displacements of ±3 cm, intensities went from 98 ± 3% to 100 ± 1% after the correction. Therefore, accurate correction of the signal collected by a camera imaging the output of scintillating elements in a 3D volume is possible. This work paves the way to the development of real-time scintillator-based deformable dosimeters.

Identification of Peptides Implicated in Antibacterial Activity of Snow Crab Hepatopancreas Hydrolysates by a Bioassay-Guided Fractionation Approach Combined with Mass Spectrometry

Snow crab (Chionoecetes opilio) by-products are a rich source of biomolecules, such as lipids, proteins, and chitin, which have not been extensively investigated. This study aims to identify antibacterial peptides to enhance the value of C. opilio by-products. After hydrolysis of different component parts using Protamex®, and concentration by solid-phase extraction, the resulting fractions were tested for antibacterial activity against Escherichia coli, Listeria innocua, and Vibrio parahaemolyticus. Hepatopancreas was the only tissue to display antibacterial activity detected using this protocol. Four fractions obtained with and without enzymatic hydrolysis of hepatopancreas followed by SPE C18 fractionation and elution with 50 and 80% acetonitrile demonstrated bacteriostatic activity against L. innocua HPB13, from concentrations of 0.30 to 43.05 mg/mL of peptides/proteins. Eleven peptides sharing at least 80% amino acid homology with four antimicrobial peptides were identified by mass spectrometry. Two peptides had homology to crustin-like and yellowfin tuna GAPDH antimicrobial peptides belonging to the marine organisms Penaeus monodon and Thunnus albacares, respectively. Other peptide sequence homologies were also identified: Odorranain-C7 from the frog Odorrana grahami and a predicted antibacterial peptide in the Asian ladybeetle Harmonia axyridis. These active peptides may represent a novel group of bioactive peptides deserving further investigation as food preservatives.

Valorization of snow crab (Chionoecetes opilio) cooking effluents for food applications

BACKGROUND

Seafood processing generates significant amounts of solid and liquid waste in the environment. Such waste represents a potential source of high-value biomolecules for food, pharmaceutic and cosmetic applications. There are very few studies on the valorization of wastewaters compared to solid by-products. However, cooking waters are characterized by a high organic polluting load, which could contain valuable molecules such as proteins, pigments and flavor compounds. Snow crab (Chionoecetes opilio) processing is included among the most important processes in Canadian fisheries, although its cooking effluent composition is not well characterized.

RESULTS

The present study concentrated and valorized the biomass in snow crab cooking wastewaters for the development of products for food applications. A membrane process was designed and optimized to concentrate the effluents. The chemical composition of the concentrates was analyzed, including characterizing the flavor profile compounds. The extracts were mainly composed of proteins (592 g kg^-1 ) and minerals (386 g kg^-1 ) and contained desirable flavor compounds. Their functional properties (solubility, water-holding capacity, oil-holding capacity) and antioxidant activities were also assessed, and their safety was verified.

CONCLUSION

The cooking effluents generated by snow crab processing facilities, usually considered as waste, can be concentrated and turned into a natural aroma for the food industry. © 2019 Society of Chemical Industry.

Antihypertensive and Angiotensin-I-Converting Enzyme (ACE)-Inhibitory Peptides from Fish as Potential Cardioprotective Compounds

The term metabolic/cardiometabolic/insulin resistance syndrome could generally be defined as the co-occurrence of several risk factors inclusive of systemic arterial hypertension. Not only that organizations, such as the world health organization (WHO) have identified high blood pressure as one of the main risk factors of the cardiometabolic syndrome, but there is also a link between the occurrence of insulin resistance/impaired glucose tolerance and hypertension that would consequently lead to type-2 diabetes (T2D). Hypertension is medicated by various classes of synthetic drugs; however, severe or mild adverse effects have been repeatedly reported. To avoid and reduce these adverse effects, natural alternatives, such as bioactive peptides derived from different sources have drawn the attention of researchers. Among all types of biologically active peptides inclusive of marine-derived ones, this paper's focus would solely be on fish and fishery by-processes' extracted peptides and products. Isolation and fractionation processes of these products alongside their structural, compositional and digestion stability characteristics have likewise been briefly discussed to better address the structure-activity relationship, expanding the reader's knowledge on research and discovery trend of fish antihypertensive biopeptides. Furthermore, drug-likeness of selected biopeptides was predicted by Lipinski's rules to differentiate a drug-like biopeptide from nondrug-like one.

Insights into the Regulation of Algal Proteins and Bioactive Peptides Using Proteomic and Transcriptomic Approaches

Oceans abound in resources of various kinds for R&D and for commercial applications. Monitoring and bioprospecting allow the identification of an increasing number of key natural resources. Macroalgae are essential elements of marine ecosystems as well as a natural resource influenced by dynamic environmental factors. They are not only nutritionally attractive but have also demonstrated potential health benefits such as antioxidant, antihypertensive, and anti-inflammatory activities. Several bioactive peptides have been observed following enzymatic hydrolysis of macroalgal proteins. In addition, significant differences in protein bioactivities and peptide extracts of wild and cultivated macroalgae have been highlighted, but the metabolic pathways giving rise to these bioactive molecules remain largely elusive. Surprisingly, the biochemistry that underlies the environmental stress tolerance of macroalgae has not been well investigated and remains poorly understood. Proteomic and functional genomic approaches based on identifying precursor proteins and bioactive peptides of macroalgae through integrated multi-omics analysis can give insights into their regulation as influenced by abiotic factors. These strategies allow evaluating the proteomics profile of regulation of macroalgae in response to different growth conditions as well as establishing a comparative transcriptome profiling targeting structural protein-coding genes. Elucidation of biochemical pathways in macroalgae could provide an innovative means of enhancing the protein quality of edible macroalgae. This could be ultimately viewed as a powerful way to drive the development of a tailored production and extraction of high value molecules. This review provides an overview of algal proteins and bioactive peptide characterization using proteomics and transcriptomic analyses.

Silver nanoparticles and dissolved silver activate contrasting immune responses and stress-induced heat shock protein expression in sea urchin

Using immune cells of sea urchin Strongylocentrotus droebachiensis in early development as a model, the cellular protective mechanisms against ionic and poly(allylamine)-coated silver nanoparticle (AgNPs; 14 ± 6 nm) treatments at 100 μg L^-1 were investigated. Oxidative stress, heat shock protein expression, and pigment production by spherulocytes were determined as well as AgNP translocation pathways and their multiple effects on circulating coelomocytes. Sea urchins showed an increasing resilience to Ag over time because ionic Ag is accumulated in a steady way, although nanoAg levels dropped between 48 h and 96 h. A clotting reaction emerged on tissues injured by dissolved Ag (present as chloro-complexes in seawater) between 12 h and 48 h. Silver contamination and nutritional state influenced the production of reactive oxygen species. After passing through coelomic sinuses and gut, AgNPs were found in coelomocytes. Inside blood vessels, apoptosis-like processes appeared in coelomocytes highly contaminated by poly(allylamine)-coated AgNPs. Increasing levels of Ag accumulated by urchins once exposed to AgNPs pointed to a Trojan-horse mechanism operating over 12-d exposure. However, under short-term treatments, physical interactions of poly(allylamine)-coated AgNPs with cell structures might be, at some point, predominant and responsible for the highest levels of stress-related proteins detected. The present study is the first report detailing nano-translocation in a marine organism and multiple mechanisms by which sea urchin cells can deal with toxic AgNPs. Environ Toxicol Chem 2017;36:1872-1886. © 2016 SETAC.