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In recent years, the increasing concern about human health well-being has strongly boosted the search for natural alternatives that can be used in different fields, especially in biomedicine. This has put microalgae-based products in evidence since they contain many bioactive compounds, of which polysaccharides are attractive due to the diverse physicochemical properties and new or improved biological roles they play. Polysaccharides from microalgae, specially exopolysaccharides, are critically important for market purposes because they can be used as anti-inflammatory, immunomodulatory, anti-glycemic, antitumor, antioxidant, anticoagulant, antilipidemic, antiviral, antibacterial, and antifungal agents. Therefore, to obtain higher productivity and competitiveness of these naturally available compounds, the cultivation parameters and the extraction/purification processes must be better optimized in order to bring perspectives for the exploitation of products in commercial and clinical practice. In this sense, the objective of the present review is to elucidate the potential biomedical applications of microalgae-derived polysaccharides. A closer look is taken at the main polysaccharides produced by microalgae, methods of extraction, purification and structural determination, biological activities and their applications, and current status., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

This study aimed to investigate the impact of different microalgal matrices on the bioaccessibility and uptake by Caco-2 cells of carotenoids and chlorophylls. In this way, the microalgal ingredients/products (whole dry biomass [WDB], whole ultrasonicated paste [WUP], and liposoluble pigment emulsion [LPE]) obtained from Chlorella vulgaris and Arthrospira platensis were submitted to in vitro simulated digestion. Apical uptake of pigments in micelles generated during the simulated digestion by Caco-2 human intestinal cells was determined. The influence of simulated digestion on carotenoid and chlorophyll stability and bioaccessibility was assessed by HPLC-PDA-MS/MS and the carotenoids and chlorophylls' bioaccessibility and cellular uptake were shown to be boosted according to the matrix (LPE > WUP > WDB). Our findings showed that Chlorella vulgaris and Arthrospira platensis could be considered in formulations when carotenoids and chlorophylls are the target molecules in the ingredients/products., (Copyright © 2022. Published by Elsevier Ltd.)

The association between inflammatory processes and intestinal neuronal destruction during the progression of Chagasic megacolon is well established. However, many other components play essential roles, both in the long-term progression and control of the clinical status of patients infected with Trypanosoma cruzi . Components such as neuronal subpopulations, enteric glial cells, mast cells and their proteases, and homeostasis-related proteins from several organic systems (serotonin and galectins) are differentially involved in the progression of Chagasic megacolon. This review is aimed at revealing the characteristics of the intestinal microenvironment found in Chagasic megacolon by using different types of already used biomarkers. Information regarding these components may provide new therapeutic alternatives and improve the understanding of the association between T. cruzi infection and immune, endocrine, and neurological system changes., Competing Interests: The authors declare that there is no conflict of interest regarding the publication of this review article., (Copyright © 2021 José Rodrigues do Carmo Neto et al.)

Organophosphate (OP) pesticides are responsible for numerous human deaths every year. Nucleophilic substitution is an important method to mitigate the toxicity of obsolete stocks of OPs. Herein, the degradation of O , O -diethyl-2,4-dinitrophenyl phosphate (DEDNPP) and pesticide diethyl-4-nitrophenyl phosphate (Paraoxon) promoted by 1,2,4-triazole (TAZ) was investigated by means of kinetic studies, nuclear magnetic resonance (NMR) analyses, and theoretical calculations. Results showed fast degradation of OPs is promoted by the anionic form of the nucleophile (TAZ(-)) in pH > 8.5 (optimal at pH = 11). Rate enhancements of 10 6 and 10 5 -fold in relation to neutral hydrolysis of DEDNPP and Paraoxon were observed, respectively, consistent with alpha-nucleophiles reactivity. TAZ(-) regioselectively promotes the degradation of DEDNPP via P-O bond break, forming a quickly hydrolyzable phosphorylated intermediate, regenerating the nucleophile. Calculations using M06-2X/6-311++G(d,p) level of theory revealed that the equivalent nitrogen atoms of TAZ(-) are the main nucleophilic center of the molecule. This study expands the knowledge on the reactivity of iminic compounds as detoxificant agents of OPs, indicating the efficiency and selectivity of TAZ(-) in aqueous medium, encouraging the design of novel TAZ-based catalysts.

The objective of this study was to evaluate the effect of carotenoids intake of Scenedesmus obliquus, on lipid peroxidation, the endogenous antioxidant defense system as well as the serum lipid profile in vivo. Male mice were divided into control groups and supplemented with different doses of microalgae carotenoids: 0.25 (MC1) and 2.5 (MC2) mg·kg -1 bodyweight. The lipid profile (total cholesterol, triglycerides, low and high-density lipoprotein) and markers of hepatic toxicity were determined in serum samples. Antioxidant enzymes and thiobarbituric acid reactive substances were determined in the heart, liver, kidneys, and spleen. Both doses used to treat the animals did not show adverse effects by markers of hepatic toxicity. MC1 did not cause significant changes in the serum lipid profile. In contrast, it created a significant reduction in lipid peroxidation of the spleen (46%) as well as an increase in the GR in the heart (40%) and GPx in the kidneys (79%) activity. The MC2 treatment also increased GR (49%) in the heart and GPx (243%) in the heart and kidneys (58%) activity, however, significantly increased levels of lipid peroxidation in the liver (160%) as well as serum triglycerides (60%). According to results, it is suggested that the consumption of S. obliquus carotenoids at the MC1 dose was safe to the animals and could be explored as an alternative to improve the activity of antioxidant enzymes and reduce lipid peroxidation., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

This brief data article refers to the previous exploration of Scenedesmus obliquus and Phormidium autumnale biomass about the possibility of using these microalgae species as an unconventional functional food. Data on chemical composition, fatty acids, volatile compounds, and carotenoid profiles were determined. In parallel, are provided the antioxidant capacity (reducing capacity - RC and reactive oxygen species deactivation - ORAC) of aqueous, lipophilic, and carotenoid extracts isolated from microalgae biomass. Both species have similar compounds in their biomass. However, S. obliquus was statistically different with a lower saturated fatty acid (STF) followed by higher mono (MUFA) and polyunsaturated (PUFA) content, also showed higher antioxidant potential for acetone extract and isolated carotenoids. On the other hand, P. autumnale aqueous extract showed high RC and ORAC. The significance of the experimental data was determined using the t -test (p < 0.05) based on the Statistica 7.0 software. These findings led us to explore the microalgae S. obliquus in an in vivo experimental model., (© 2020 The Authors.)

Environmental factors directly affect the growth and composition of microalgal biomass. Therefore, the present work analyzed the metabolomics (amino acids, organic acids, and fatty acids) of the microalga Scenedesmus obliquus cultivated in 24:0 and 12:12 (light:dark) photoperiods and different phases of cell growth. Furthermore, the metabolites were related to protein, lipid, and chlorophyll contents at the end of cultivation. The highest biomass concentration (4020 mg L - 1 ) and protein (47.3%) were obtained in culture under constant illumination. The cultivation 12:12 (light:dark) photoperiod triggered higher production of lipids (23.0%) and chlorophylls (26.4 mg g - 1 ) by S. obliquus. Microalgal metabolites were greatly affected by photoperiod and by phase of cell growth. Thus, metabolite production could be related to both the environmental conditions under which cultivation occurred and to the different concentrations of products (proteins, lipids, and chlorophylls) present in the S. obliquus biomass.

The aim of this study was to assess the potential of nanoparticles to improve the pharmacokinetics of curcumin, with a primary goal of enhancing its bioavailability. Polylactic-co-glycolic acid (PLGA) and PLGA-polyethylene glycol (PEG) (PLGA-PEG) blend nanoparticles containing curcumin were obtained by a single-emulsion solvent-evaporation technique, resulting in particles size smaller than 200 nm. The encapsulation efficiency was over 70% for both formulations. The in vitro release study showed that curcumin was released more slowly from the PLGA nanoparticles than from the PLGA-PEG nanoparticles. A LC-MS/MS method was developed and validated to quantify curcumin in rat plasma. The nanoparticles were orally administered at a single dose in rats, and the pharmacokinetic parameters were evaluated and compared with the curcumin aqueous suspension. It was observed that both nanoparticles formulations were able to sustain the curcumin delivery over time, but greater efficiency was obtained with the PLGA-PEG nanoparticles, which showed better results in all of the pharmacokinetic parameters analyzed. The PLGA and PLGA-PEG nanoparticles increased the curcumin mean half-life in approximately 4 and 6h, respectively, and the C(max) of curcumin increased 2.9- and 7.4-fold, respectively. The distribution and metabolism of curcumin decreased when it was carried by nanoparticles, particularly PLGA-PEG nanoparticles. The bioavailability of curcumin-loaded PLGA-PEG nanoparticles was 3.5-fold greater than the curcumin from PLGA nanoparticles. Compared to the curcumin aqueous suspension, the PLGA and PLGA-PEG nanoparticles increased the curcumin bioavailability by 15.6- and 55.4-fold, respectively. These results suggest that PLGA and, in particular, PLGA-PEG blend nanoparticles are potential carriers for the oral delivery of curcumin., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Increasing attention is current focused on urban groundwater contamination with gasoline hydrocarbon compounds in Brazil. The compounds benzene, toluene, ethylbenzene, and xylenes (BTEX) contained in fuels are highly toxic and can have severe public health consequences, besides posing the risk of intake from the water table by way of contamination. After two years of a steady gasoline storage tank leak, water samples from private household wells in the district of Brisa Mar, Itaguaí, Rio de Janeiro State, were analyzed and the concentration of BTEX compounds was evaluated. Two out of ten water samples from the study area presented BTEX concentrations above the National Water Quality Standard (Brazilian Health Ministry Ruling No. 1469/2000), in which the maximum permissible benzene concentration is 5 micro g.L-1. Four others wells were also contaminated with nitrate, responsible for the induction of methemoglobinemia. Natural attenuation (intrinsic biodegradation) mechanisms through electron acceptors was also investigated in this study.