Fast Profiling of Natural Pigments in Different Spirulina (Arthrospira platensis) Dietary Supplements by DI-FT-ICR and Evaluation of their Antioxidant Potential by Pre-Column DPPH-UHPLC Assay

Unique photosynthetic strategies employed by closely related Breviolum minutum strains under rapid short-term cumulative heat stress

The thermal tolerance of symbiodiniacean photo-endosymbionts largely underpins the thermal bleaching resilience of their cnidarian hosts such as corals and the coral model Exaiptasia diaphana. While variation in thermal tolerance between species is well documented, variation between conspecific strains is understudied. We compared the thermal tolerance of three closely related strains of Breviolum minutum represented by two internal transcribed spacer region 2 profiles (one strain B1-B1o-B1g-B1p and the other two strains B1-B1a-B1b-B1g) and differences in photochemical and non-photochemical quenching, de-epoxidation state of photopigments, and accumulation of reactive oxygen species under rapid short-term cumulative temperature stress (26-40 °C). We found that B. minutum strains employ distinct photoprotective strategies, resulting in different upper thermal tolerances. We provide evidence for previously unknown interdependencies between thermal tolerance traits and photoprotective mechanisms that include a delicate balancing of excitation energy and its dissipation through fast relaxing and state transition components of non-photochemical quenching. The more thermally tolerant B. minutum strain (B1-B1o-B1g-B1p) exhibited an enhanced de-epoxidation that is strongly linked to the thylakoid membrane melting point and possibly membrane rigidification minimizing oxidative damage. This study provides an in-depth understanding of photoprotective mechanisms underpinning thermal tolerance in closely related strains of B. minutum.

Beneficial Effects of Spirulina Supplementation in the Management of Cardiovascular Diseases

In recent decades, as a result of rising mortality rates due to cardiovascular diseases (CVDs), there has been a growing urgency to find alternative approaches to conventional pharmaceutical treatment to prevent the onset of chronic diseases. Arthrospira platensis, commonly known as Spirulina, is a blue-green cyanobacterium, classified as a "superfood", used worldwide as a nutraceutical food supplement due to its remarkable nutritional value, lack of toxicity, and therapeutic effects. Several scientific studies have evaluated the cardioprotective role of Spirulina. This article presents a comprehensive review of the therapeutic benefits of Spirulina in improving cardio- and cerebrovascular health. It focuses on the latest experimental and clinical findings to evaluate its antihypertensive, antidiabetic, and antihyperlipidemic properties. The objective is to highlight its potential in preventing and managing risk factors associated with cardiovascular disease (CVD).

A multiplex metabolomic approach for quality control of Spirulina supplement and its allied microalgae (Amphora & Chlorella) assisted by chemometrics and molecular networking

Microalgae species are of economic importance regarded as "green gold" being rich in bioactive compounds. Spirulina and Chlorella are the most popular microalgal species and are marketed as healthy food supplements. At the same time, Amphora holds potential as a source of healthy lipids and essential fatty acids. Yet, there are considerable variations in their reported chemical composition, and less is known about their compositional differences. A multiplexed metabolomic approach was adopted for the quality control (QC) of Spirulina supplements and to compare its constitutive metabolome to Chlorella and Amphora. The adopted protocol comprised gas chromatography-mass spectrometry (GC-MS), ultra-high performance liquid chromatography coupled with high-resolution tandem mass spectrometry (UPLC-HRMS/MS), and ultraviolet-visible spectrophotometry (UV/Vis) for mapping their primary and secondary metabolome. Interestingly, UPLC-HRMS/MS analysis delineated the abundance of fatty acids in Amphora versus glycolipids enrichment in Spirulina, and porphyrins were the main pigments identified in Spirulina, with scarce occurrence in Chlorella. Orthogonal projections to latent structures discriminant analysis (OPLS-DA) analysis of GC-MS data set revealed palmitic acid, 3-mannobiose, and glyceryl-glycoside as being most enriched in Spirulina, versus sucrose and leucine in Chlorella and Amphora, respectively. Despite being of low discriminatory potential, UV/Vis OPLS-DA modeling showed that Spirulina was distinguished with the UV absorbances of carotenoids and chlorophyll pigments, as indicated by its OPLS-DA derived S-plot. Our study provides a QC approach for the analysis of the microalgal species and poses alternative spectral and compositional markers for their discrimination.

Therapeutic Potentials of Microalgae and Their Bioactive Compounds on Diabetes Mellitus

Diabetes mellitus is a metabolic disorder characterized by hyperglycemia due to impaired insulin secretion, insulin resistance, or both. Oxidative stress and chronic low-grade inflammation play crucial roles in the pathophysiology of diabetes mellitus. There has been a growing interest in applying natural products to improve metabolic derangements without the side effects of anti-diabetic drugs. Microalgae biomass or extract and their bioactive compounds have been applied as nutraceuticals or additives in food products and health supplements. Several studies have demonstrated the therapeutic effects of microalgae and their bioactive compounds in improving insulin sensitivity attributed to their antioxidant, anti-inflammatory, and pancreatic β-cell protective properties. However, a review summarizing the progression in this topic is lacking despite the increasing number of studies reporting their anti-diabetic potential. In this review, we gathered the findings from in vitro, in vivo, and human studies to discuss the effects of microalgae and their bioactive compounds on diabetes mellitus and the mechanisms involved. Additionally, we discuss the limitations and future perspectives of developing microalgae-based compounds as a health supplement for diabetes mellitus. In conclusion, microalgae-based supplementation has the potential to improve diabetes mellitus and be applied in more clinical studies in the future.

Single-filament imaging mass spectrometry lipidomics in Arthrospira platensis

RATIONALE

Elucidating intra-organismal biochemical and lipid organization in photosynthetic biological cell factories of filamentous cyanobacteria, such as Arthrospira platensis (Spirulina), is important for tracking physiological response mechanisms during growth. Little is known about the filaments' biochemical organization and cellular structure and no label-free imaging techniques exist that provide molecular mapping.

METHODS

We applied ultrahigh-resolution mass spectrometry (MS) with matrix-assisted laser desorption ionization (MALDI) imaging to immobilized Spirulina filaments to investigate the localization of lipids across distinct physiological regions. We optimized matrix selection and deposition methods with the goal of facilitating high spatial, and intra-filament, resolution using untargeted multivariate statistical spectral deconvolution across MS pixels.

RESULTS

Our results demonstrate an improved two-step matrix application with an optimized procedure for intra-organismal lipid profiling to improve analyte sensitivity and achieve higher spatial resolution. We evaluate several conventional matrices, namely 2,5-dihydroxybenzoic acid (DHB), superDHB (sDHB), 1,5-diaminonaphthalene (DAN), and a 50:50 mix of DHB and sDHB, and compare delineation and pixel-based elucidation of intra-filament lipidomics. We identified a total of 1626 features that could be putatively assigned a lipid-like formula based on database query and 46 unique features, with associated lipid assignments that were significantly distinct in their intra-filament location.

CONCLUSIONS

MALDI imaging MS with untargeted statistical spectral deconvolution was used to visualize intra-filament lipidomics organization in Spirulina filaments. Improvements in matrix deposition, including sequential sublimation and pneumatic spraying, increased signal abundance at high spatial resolution and allowed for identification of distinct lipid composition regions. This work outlines a methodology that may be used for micro-ecological untargeted molecular phenotyping.

Hyphenation of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) with separation methods: The art of compromises and the possible - A review

This review provides an overview of the online hyphenation of Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) with separation methods to date. The online coupling between separation techniques (gas and liquid chromatography, capillary electrophoresis) and FT-ICR MS essentially raises questions of compromise and is not look as straightforward as hyphenation with other analyzers (QTOF-MS for instance). FT-ICR MS requires time to reach its highest resolving power and accuracy in mass measurement capabilities whereas chromatographic and electrophoretic peaks are transient. In many applications, the strengths and the weaknesses of each technique are balanced by their hyphenation. Untargeted "Omics" (e.g. proteomics, metabolomics, petroleomics, …) is one of the main areas of application for FT-ICR MS hyphenated to online separation techniques because of the complexity of the sample. FT-ICR MS achieves the required high mass measurement accuracy to determine accurate molecular formulae and resolution for isobar distinction. Meanwhile separation techniques highlight isomers and reduce the ion suppression effects extending the dynamic range. Even if the implementation of FT-ICR MS hyphenated with online separation methods is a little trickier (the art of compromise), this review shows that it provides unparalleled results to the scientific community (the art of the possible), along with raising the issue of its future in the field with the relentless technological progress.

In Vitro Characterization of Limosilactobacillus reuteri Lac Ib01 (OL468126.1) Isolated from Traditional Sheep Dry Sausage and Evaluation of the Activity of Arthrospira platensis or Phycocyanin on Its Growth-Promoting Ability

The positive impact of probiotic strains on human health is more evident than ever. To achieve the beneficial health effects and desirable functional properties of probiotics, sufficient numbers of these microorganisms must reach the intestinal tract with high survival rates. The purpose of this study was to identify and characterize a novel strain of Limosilactobacillus reuteri isolated from traditional sheep dry sausage and evaluate its growth-promoting ability with the addition of Arthrospira platensis or phycocyanin extract. In vitro experimental approaches were conducted to determine the physiological features of the candidate probiotic isolate, including biochemical identification, 16S rRNA gene sequencing, tolerance assays to acid and bile salts, antimicrobial activities, adherence ability, and antiproliferative assays. The effects of A. platensis or phycocyanin (0, 1, 5, and 8 mg/mL) on the growth of probiotic cultures were studied after 0, 24, 48, and 72 h. Our results showed that the isolated Limosilactobacillus reuteri (OL468126.1) possesses desirable characteristics as a probiotic candidate and can, therefore, be used as an ingredient in functional foods. Furthermore, A. platensis and phycocyanin extract have great potential for enhancing the growth and prolonging the stationary phase of isolated probiotics. Our findings showed that phycocyanin extract not only plays the role of a natural pigment but also acts as a growth promoter of probiotics.

On-line pre-column FRAP-based antioxidant reaction coupled with HPLC-DAD-TOF/MS for rapid screening of natural antioxidants from different parts of Polygonum viviparum†

Polygonum viviparum L. (PV) is a widely used resource plant with high medicinal, feeding and ecological values. Our studies show that PV has strong antioxidant activity. However, up to date, the antioxidant activity and components in other parts were not fully elucidated. In the present study, a new online pre-column ferric ion reducing antioxidant power (FRAP)-based antioxidant reaction coupled with high performance liquid chromatography-diode array detector-quadrupole-time-of-flight mass spectrometry (HPLC-DAD-TOF/MS) was developed for rapid and high-throughput screening of natural antioxidants from three different parts of PV including stems and leaves, fruits and rhizomes. In this procedure, it was assumed that the peak areas of compounds with potential antioxidant activity in HPLC chromatograms would be greatly diminished or vanish after incubating with the FRAP. The online incubation conditions including mixed ratios of sample and FRAP solution and reaction times were firstly optimized with six standards. Then, the repeatability of the screening system was evaluated by analysis of the samples of stems and leaves of PV. As a result, a total of 21 compounds mainly including flavonoids and phenolic acids were screened from the three parts of PV. In conclusion, the present study provided a simple and effective strategy to rapidly screen antioxidants in natural products.

Polygonum viviparum L. (PV) is a widely used resource plant with high medicinal, feeding and ecological values.

Chemical Identification and Antioxidant Screening of Bufei Yishen Formula using an Offline DPPH Ultrahigh-Performance Liquid Chromatography Q-Extractive Orbitrap MS/MS

Chronic obstructive pulmonary disease (COPD) has high morbidity and mortality and presents a threat to human health worldwide. Numerous clinical trials have confirmed that Bufei Yishen formula (BYF), an herbal medicine, can alleviate the symptoms of COPD by reducing oxidative stress-mediated inflammation. However, the active components of BYF remain unclear. We developed an efficient ultrahigh-performance liquid chromatography Q-Extractive Orbitrap mass spectrometry method to identify the composition of BYF and determine its antioxidant profile through an offline screening strategy based on 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH)-liquid chromatography-mass spectrometry. In total, 189 compounds were identified in BYF extract, including 83 flavonoids, 24 lignans, 20 alkaloids, 15 saponins, 11 terpenoid, 10 saccharides, eight lipids, seven organic acids, two coumarins, two amino acids, and seven other compounds. Among them, 79 compounds were found to have a potential antioxidant activity. In vitro validation indicated that the free radical scavenging activities of rosmarinic acid and calycosin were similar to that of the positive control (DPPH IC50 = 25.72 ± 1.02 and 147.23 ± 25.12 μg/mL, respectively). Furthermore, calycosin had a high content in serum after the oral administration of BYF, indicating that calycosin might be the major antioxidant compound in BYF.

Sustainable Microalgae and Cyanobacteria Biotechnology

Marine organisms are a valuable source of new compounds, many of which have remarkable biotechnological properties, such as microalgae and cyanobacteria, which have attracted special attention to develop new industrial production routes. These organisms are a source of many biologically active molecules in nature, including antioxidants, immunostimulants, antivirals, antibiotics, hemagglutinates, polyunsaturated fatty acids, peptides, proteins, biofuels, and pigments. The use of several technologies to improve biomass production, in the first step, industrial processes schemes have been addressed with different accomplishments. It is critical to consider all steps involved in producing a bioactive valuable compound, such as species and strain selection, nutrient supply required to support productivity, type of photobioreactor, downstream processes, namely extraction, recovery, and purification. In general, two product production schemes can be mentioned; one for large amounts of product, such as biodiesel or any other biofuel and the biomass for feeding purposes; the other for when the product will be used in the human health domain, such as antivirals, antibiotics, antioxidants, etc. Several applications for microalgae have been documented. In general, the usefulness of an application for each species of microalgae is determined by growth and product production. Furthermore, the use of OMICS technologies enabled the development of a new design for human therapeutic recombinant proteins, including strain selection based on previous proteomic profiles, gene cloning, and the development of expression networks. Microalgal expression systems have an advantage over traditional microbial, plant, and mammalian expression systems for new and sustainable microalga applications, for responsible production and consumption.

Rapid analytical methods for the microalgal and cyanobacterial biorefinery: Application on strains of industrial importance

To realize the potential of microalgae in the biorefinery context, exploitation of multiple products is necessary for profitability and bioproduct valorization. Appropriate analytical tools are required for growth optimization, culture monitoring, and quality control purposes, with safe, low-tech, and low-cost solutions favorable. Rapid, high-throughput, and user-friendly methodologies were devised for (a) determination of phycobiliproteins, chlorophylls, carotenoids, proteins, carbohydrates, and lipids and (b) qualitative and quantitative carotenoid profiling using UPLC-PDA-MS^E . The complementary methods were applied on 11 commercially important microalgal strains including prasinophytes, haptophytes, and cyanobacteria, highlighting the suitability of some strains for coproduct exploitation and the method utility for research and industrial biotechnology applications. The UPLC method allowed separation of 41 different carotenoid compounds in <15 min. Simple techniques are described for further quantification and comparison of pigment profiles, allowing for easy strain selection and optimization for pigment production, with suitability for biotechnological or biomedical applications.

Cyanobacteria-From the Oceans to the Potential Biotechnological and Biomedical Applications

Cyanobacteria are photosynthetic prokaryotic organisms which represent a significant source of novel, bioactive, secondary metabolites, and they are also considered an abundant source of bioactive compounds/drugs, such as dolastatin, cryptophycin 1, curacin toyocamycin, phytoalexin, cyanovirin-N and phycocyanin. Some of these compounds have displayed promising results in successful Phase I, II, III and IV clinical trials. Additionally, the cyanobacterial compounds applied to medical research have demonstrated an exciting future with great potential to be developed into new medicines. Most of these compounds have exhibited strong pharmacological activities, including neurotoxicity, cytotoxicity and antiviral activity against HCMV, HSV-1, HHV-6 and HIV-1, so these metabolites could be promising candidates for COVID-19 treatment. Therefore, the effective large-scale production of natural marine products through synthesis is important for resolving the existing issues associated with chemical isolation, including small yields, and may be necessary to better investigate their biological activities. Herein, we highlight the total synthesized and stereochemical determinations of the cyanobacterial bioactive compounds. Furthermore, this review primarily focuses on the biotechnological applications of cyanobacteria, including applications as cosmetics, food supplements, and the nanobiotechnological applications of cyanobacterial bioactive compounds in potential medicinal applications for various human diseases are discussed.

Expanding the Scope of Detectable Microbial Natural Products by Complementary Analytical Methods and Cultivation Systems

Recent advances in genome sequencing have unveiled a large discrepancy between the genome-encoded capacity of microorganisms to produce secondary metabolites and the number detected. In this work, a two-platform mass spectrometry analysis for the comprehensive secondary metabolomics characterization of nine myxobacterial strains, focusing on extending the range of detectable secondary metabolites by diversifying analytical methods and cultivation conditions, is presented. Direct infusion measurements of crude extracts on a Fourier transform ion cyclotron resonance mass spectrometer are compared to a time-of-flight device coupled to liquid chromatography measurements. Both methods are successful in detecting known metabolites, whereas statistical analysis of unknowns highlights their complementarity: Strikingly, 82-99% of molecular features detected with one setup were not detectable with the other. Metabolite profile differences from our set of strains grown in liquid culture versus their swarming colonies on agar plates were evaluated. The detection of up to 96% more molecular features when both liquid and plate cultures were analyzed translates into increased chances to identify new secondary metabolites. Discrimination between primary and secondary metabolism in combination with GNPS molecular networking revealed strain Mx3 as particularly promising for the isolation of novel secondary metabolites among the nine strains investigated in this study.

Analysis of the metabolic switch induced by the spirulina peptide SP6 in high fat diet ApoE-/- mice model: A direct infusion FT-ICR-MS based approach

Atherosclerosis, dyslipidemia and hypertension are comorbid diseases often found in combination. Among different pharmacological approaches the employment of natural multifunctional peptides is an attractive option as side therapy. Mass spectrometry-based metabolomics provide valuable information on metabolic changes and can be useful to elucidate peptide pharmacodynamics. In this this work we performed a preliminary investigation on the potential effect of a recently characterized Spirulina platensis peptide named SP6 (GIVAGDVTPI) on the modulation of metabolism in a high fat diet ApoE^-/- mice atherosclerotic model. A direct infusion Fourier transform ion cyclotron resonance mass spectrometry (DI-FT-ICR-MS) approach was used to elucidate polar and non-polar metabolites extracted by mice plasma following four weeks SP6 treatment. The method delivered fast analysis time, repeatability, high mass accuracy and resolution for unambiguous molecular formula assignment. Multivariate statistical analysis (PLS-DA) highlighted a clear class separation, revealing the alteration of numerous metabolites levels belonging to different classes. In particular sphingolipids, glycerophospholipids, TCA cycle intermediates, and amino acids, which are key players in the atherosclerotic process and progression, were upregulated in saline alone HFD ApoE^-/- group, while were sensibly decreased after treatment with SP6 peptide. These results could open the way to further, large-scale, investigation of SP6 peptide effects in the regulation of atherosclerotic disease development and progression, and show the potential of DI-FT-ICR as fast analytical tool to take snaphshots of metabolic changes before moving to targeted MS-based approaches.

Antioxidant activities of some edaphic algae in Egypt

Background

Algae in general characterized by their rich content of biological compounds. However, few studies were conducted on the soil-inhabiting algae and their antioxidant characteristics.

Results

The present study was designed to evaluate the antioxidant activity of four edaphic algae including one on-soil alga (Vaucheria geminata) and three axenic isolated in-soil algae (Pleurochloris pyrenoidosa, Botrydiopsis eriensis, and Scenedesmus obliquus). Total antioxidant activity by Phosphomolybdenum assay ranged from 6.66 to 36.33 mg of Asc/g dwt; meanwhile, the percentage inhibition of DPPH radical was up to 97.37%. Antioxidant activity of each alga was assessed also by measuring their contents of total phenols, flavonoids, and pigments (chlorophyll a and carotenoids). B. eriensis and S. obliquus recorded the highest levels of phenols, flavonoids, and chlorophyll a followed by P. pyrenoidosa and V. geminata, while B. eriensis showed the highest carotenoids content. Moreover, about seven types of each phenol and flavonoid compound were identified by HPLC chromatography in the four algae under investigation. The most common detected phenols were gallic, chlorogenic, caffeic, and ferulic, while rutin, quercetin, apigenin, and quercitrin were the most abundant flavonoids among all algae under investigation.

Conclusion

All the tested algae were characterized with high antioxidant activities besides the rich contents of compounds with antioxidant properties which recommend their further potential using in nutritional, pharmaceutical, and medicinal implications.

A Novel Promising Frontier for Human Health: The Beneficial Effects of Nutraceuticals in Cardiovascular Diseases

Cardiovascular diseases (CVDs) such as hypertension, atherosclerosis, myocardial infarction, and diabetes are a significant public health problem worldwide. Although several novel pharmacological treatments to reduce the progression of CVDs have been discovered during the last 20 years, the better way to contain the onset of CVDs remains prevention. In this regard, nutraceuticals seem to own a great potential in maintaining human health, exerting important protective cardiovascular effects. In the last years, there has been increased focus on identifying natural compounds with cardiovascular health-promoting effects and also to characterize the molecular mechanisms involved. Although many review articles have focused on the individual natural compound impact on cardiovascular diseases, the aim of this manuscript was to examine the role of the most studied nutraceuticals, such as resveratrol, cocoa, quercetin, curcumin, brassica, berberine and Spirulina platensis, on different CVDs.

Engineering the Unicellular Alga Phaeodactylum tricornutum for Enhancing Carotenoid Production

Microalgae represent a promising resource for the production of beneficial natural compounds due to their richness in secondary metabolites and easy cultivation. Carotenoids feature among distinctive compounds of many microalgae, including diatoms, which owe their golden color to the xanthophyll fucoxanthin. Carotenoids have antioxidant, anti-obesity and anti-inflammatory properties, and there is a considerable market demand for these compounds. Here, with the aim to increase the carotenoid content in the model diatom Phaeodactylum tricornutum, we exploited genetic transformation to overexpress genes involved in the carotenoid biosynthetic pathway. We produced transgenic lines over-expressing simultaneously one, two or three carotenoid biosynthetic genes, and evaluated changes in pigment content with high-performance liquid chromatography. Two triple transformants over-expressing the genes Violaxanthin de-epoxidase (Vde), Vde-related (Vdr) and Zeaxanthin epoxidase 3 (Zep3) showed an accumulation of carotenoids, with an increase in the fucoxanthin content up to four fold. Vde, Vdr and Zep3 mRNA and protein levels in the triple transformants were coherently increased. The exact role of these enzymes in the diatom carotenoid biosynthetic pathway is not completely elucidated nevertheless our strategy successfully modulated the carotenoid metabolism leading to an accumulation of valuable compounds, leading the way toward improved utilization of microalgae in the field of antioxidants.

Comparison of Online Comprehensive HILIC × RP and RP × RP with Trapping Modulation Coupled to Mass Spectrometry for Microalgae Peptidomics

In this work, two online comprehensive two-dimensional liquid chromatography platforms, namely Hydrophilic interaction liquid chromatography × Reversed phase (HILIC × RP) and Reversed phase × Reversed Phase (RP × RP) coupled to mass spectrometry, were compared for the analysis of complex peptide samples. In the first dimension, a HILIC Amide and C18 Bioshell peptide (150 × 2.1 mm, 1.7 and 2.0 μm) columns were selected, while, in the second dimension, a short C18 (50 × 3.0 mm, 2.7 μm) Bioshell peptide column was used. Two C18 trapping columns (10 × 3.0 mm, 1.9 μm), characterized by high retention and surface area, were employed as modulation interface in both HILIC × RP and RP × RP methods. The LC × LC platforms were coupled to UV and tandem mass spectrometry detection and tested for the separation and identification of two gastro-intestinal digests of commercial microalgae formulations (Spirulina Platensis and Klamath). Their performances were evaluated in terms of peak capacity, maximum number and properties of identified phycocyanin peptides. Our results showed that the HILIC × RP approach provided the highest peak capacity values (nc HILIC × RP: 932 vs. nc RP × RP: 701) with an analysis time of 60 min, while the RP × RP approach was able to identify a slight higher number of phycocyanin derived peptides (HILIC × RP: 88 vs. RP × RP: 103). These results point out the flexibility and potential of HILIC × RP and RP × RP based on trapping modulation for peptide mapping approaches.

Development of Chitosan/Mannitol Microparticles as Delivery System for the Oral Administration of a Spirulina Bioactive Peptide Extract

Spirulina platensis contains several compounds showing nutritional and therapeutic benefits. Recently, a series of peptides able to reduce the blood pressure level and to enhance the endothelial vasorelaxation was isolated from the hydrolyzed highly water-soluble Spirulina extract (HSE). However, HSE shows critical organoleptic characteristics also having poor intestinal permeability, limiting absorption when orally delivered. This research aims to overcome the critical issues through the encapsulation of HSE in Chitosan/Mannitol—(CM)-based microparticles by spray drying. The produced powders (CM-HSE) showed good process yield (≈70%) and encapsulation efficiency (≈100%) also having good derived flow properties as well as stability up to six months storage. The microparticles constituting the spray-dried powder resulted in an amorphous micrometric state (d₅₀ ≈ 14 µm) able to retain dark colour and unpleasant smell of raw HSE. Moreover, the in vitro permeation study by Franz cell indicated that the engineered microparticles are able to enhance the permeation of HSE through an intestinal biomimetic barrier (551.13 μg/cm² CM-HSE vs. 315.46 μg/cm² HSE at 270 min).

Mass-production and biomarker-based characterization of high-value Spirulina powder for nutritional supplements

Mass-produced Spirulina powder was characterized based on biomarkers for quality assessment. Other Spirulina powder products for functional foods and animal feeds were used as controls. In this study, Spirulina platensis was mass-cultured in modified Spirulina medium using a dispersive two-ton scale reactor for 30 days. After processing, the Spirulina powder was evaluated using FE-SEM and XPS. In the extracts, chlorophylls were determined using TLC and Q-TOF. SDS-PAGE and DSC were used to analyze protein biomarkers and to monitor thermal stability. The powder presented a microscale distorted sphere. Zinc, iron and calcium were detected on the powder surface. In the extracts, chlorophylls-a, -b, and -c, allophycocyanin, and phycocyanin-C were detected. Despite the similar morphology of all Spirulina products, the mass-produced Spirulina powder showed prolonged protein stability in biochemical compositions. The results suggest that mass-produced Spirulina powder can be characterized using biomarker-based advanced techniques. This protocol can be extended to other microalgae.

Novel Potent Decameric Peptide of Spirulina platensis Reduces Blood Pressure Levels Through a PI3K/AKT/eNOS-Dependent Mechanism

Considered as a superfood of the future, Spirulina platensis matrix has been extensively used because of its beneficial effect on the management of cardiovascular diseases. However, its nutraceutical properties, bioactive compounds, and molecular mechanisms are unknown. Here, we demonstrate that S platensis matrix processed in vitro by simulated gastrointestinal digestion induces direct endothelial nitric oxide (NO)-mediated vasorelaxation of resistance vessels in mice. To gain insight into the bioactive compounds responsible for this effect, we used a complex multistep peptidomic approach to fractionate the crude digest: of the 5 peptide fractions identified (A-E), only fraction E evoked vasorelaxation. High-resolution mass spectrometry-based screening revealed in E the presence of 4 main peptides (SP3-SP6 [spirulina peptides]), of which only SP6 (GIVAGDVTPI) exerted direct endothelium-dependent vasodilation of ex vivo vessels, an effect occurring via a PI3K (phosphoinositide-3-kinase)/AKT (serine/threonine kinase Akt) pathway converging on NO release. In vivo, administration of SP6 evoked a significant hemodynamic effect, reducing blood pressure, an action absent in eNOS (endothelial NO synthase)-deficient mice. Of note, although lower doses of SP6 had no hemodynamic effects, it still enhanced endothelial NO vasorelaxation. Finally, in an experimental model of arterial hypertension, SP6 exerted an antihypertensive effect, improving endothelial vasorelaxation associated with enhanced serum nitrite levels. Based on our results, this novel decameric peptide may extend the possible fields of application for spirulina-derived peptides and could be developed into a promising nonpharmacological approach for the containment of pathologies associated with vascular NO misregulation.

Yield parameters and antioxidant compounds of tomato fruit: the role of plant defence inducers with or without Cucumber mosaic virus infection

BACKGROUND

The production of fruit and vegetables rich in health-promoting components in an eco-friendly context represents the winning answer to the world population demand for food. In this study, the effects of different treatments on the yield and fruit chemical characteristics of tomato (Solanum lycopersicum L.) are reported. The treatments included three inducers of plant defence responses (chitosan, Trichoderma harzianum T-22 and Bacillus subtilis QST713) applied alone or before Cucumber mosaic virus infection. Fruit production and antioxidant compounds were investigated by ultrahigh-performance liquid chromatography (UHPLC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS).

RESULTS

Compared to control fruit harvested from untreated and healthy plants, treatment with QST713 increased the fruit number. Furthermore, plant treatments with T22, QST713 and chitosan alone enhanced fruit carotenoids (lutein and β-carotene), ascorbic acid and phenolic acids (caffeoyl glucoside and p-coumaroyl glucoside). In parallel, compared to fruit harvested from only CMV-infected plants, treatments with T22, QST713 and chitosan before CMV enhanced fruit ascorbic acid and flavonoids (quercetin 3-O-xylosyl-rutinoside and rutin).

CONCLUSION

Antioxidant compounds of tomato fruit can increase with the application of the plant defence inducers, thus protecting both the consumer and plant health. © 2019 Society of Chemical Industry.

First Apocarotenoids Profiling of Four Microalgae Strains

Both enzymatic or oxidative carotenoids cleavages can often occur in nature and produce a wide range of bioactive apocarotenoids. Considering that no detailed information is available in the literature regarding the occurrence of apocarotenoids in microalgae species, the aim of this study was to study the extraction and characterization of apocarotenoids in four different microalgae strains: Chlamydomonas sp. CCMP 2294, Tetraselmis chuii SAG 8-6, Nannochloropsis gaditana CCMP 526, and Chlorella sorokiniana NIVA-CHL 176. This was done for the first time using an online method coupling supercritical fluid extraction and supercritical fluid chromatography tandem mass spectrometry. A total of 29 different apocarotenoids, including various apocarotenoid fatty acid esters, were detected: apo-12’-zeaxanthinal, β-apo-12’-carotenal, apo-12-luteinal, and apo-12’-violaxanthal. These were detected in all the investigated strains together with the two apocarotenoid esters, apo-10’-zeaxanthinal-C4:0 and apo-8’-zeaxanthinal-C8:0. The overall extraction and detection time for the apocarotenoids was less than 10 min, including apocarotenoids esters, with an overall analysis time of less than 20 min. Moreover, preliminary quantitative data showed that the β-apo-8’-carotenal content was around 0.8% and 2.4% of the parent carotenoid, in the C. sorokiniana and T. chuii strains, respectively. This methodology could be applied as a selective and efficient method for the apocarotenoids detection.

Solid Matrix-Supported Supercritical CO₂ Enhances Extraction of γ-Linolenic Acid from the Cyanobacterium Arthrospira (Spirulina) platensis and Bioactivity Evaluation of the Molecule in Zebrafish

Marine cyanobacteria represent a large untapped source of functional glycolipids enriched with polyunsaturated fatty acids (PUFAs) for human health. However, advanced methods for scalable isolation of diverse species containing high-purity PUFA-rich glycolipids will have to be developed and their possible pharmaceutical and nutraceutical functions identified. This paper introduces a novel solid matrix-supported supercritical CO₂ extraction method for scalable isolation of the PUFA γ-linolenic acid (GLA)-enriched glycolipids from the cyanobacterium Arthrospira (Spirulina) platensis, which has been the most widely used among microalgae in the nutraceutical and pharmaceutical industries. Of various porous materials studied, diatomite was the best to facilitate extraction of GLA-rich glycolipids, resulting in an extraction efficiency of 98%. Gamma-linolenic acid made up 35% of total fatty acids (TFAs) in the extracts, which was considerably greater than that obtained with ethanol (26%), Bligh and Dyer (24%), and in situ transesterification (24%) methods, respectively. Lipidomics analysis revealed that GLA was exclusively associated with galactolipids. Pharmaceutical functions of GLA-rich galactolipids were investigated on a zebrafish caudal fin regeneration model. The results suggested that GLA extracted from A. platensis possessed anti-oxidative, anti-inflammatory, and anti-allergic activities, which acted in a concerted manner to promote post-injury regeneration of zebrafish.

A Boost in Mitochondrial Activity Underpins the Cholesterol-Lowering Effect of Annurca Apple Polyphenols on Hepatic Cells

Reduction in cholesterol blood levels represents one of the therapeutic goals to achieve in order to reduce the occurrence of cardiovascular diseases. Commonly, this goal is attempted by promoting healthy lifestyle behaviors and low-fat diets. Recently, several nutraceuticals have been shown to possess cholesterol-lowering properties and are becoming common over the counter products. Among others, apple polyphenols efficiently lower total cholesterol levels in humans and impact overall lipid metabolism. Malus Pumila Miller cv Annurca is an apple native to Southern Italy presenting one of the highest content of procyanidin B2, a dimeric procyanidin. Tested in clinical trials, the oral consumption of an Annurca polyphenolic extract (AAE) exerted a cholesterol-lowering effect similar to the statins Atorvastatin and Simvastatin. Despite AAE activity, the analysis of the molecular mechanism behind its cholesterol-lowering effect is unclear. Using isotope labeling and high-resolution mass spectrometry approaches we here performed a metabolic profiling of in vitro cultured human hepatocytes treated with AAE to reveal its mechanism of action. The results show that AAE acts differently than statins. The extract reprograms hepatic cell metabolism and promotes mitochondrial respiration, lipolysis and fatty acid β-oxidation. Citrate and acetyl-CoA, both necessary for the production of cholesterol, are diverted to the Krebs Cycle by AAE, that, ultimately, lowers cholesterogenesis and fatty acid synthesis.

Annurca Apple Polyphenols Protect Murine Hair Follicles from Taxane Induced Dystrophy and Hijacks Polyunsaturated Fatty Acid Metabolism toward β-Oxidation

Chemotherapy-induced alopecia (CIA) is a common side effect of conventional chemotherapy and represents a major problem in clinical oncology. Even months after the end of chemotherapy, many cancer patients complain of hair loss, a condition that is psychologically difficult to manage. CIA disturbs social and sexual interactions and causes anxiety and depression. Synthetic drugs protecting from CIA and endowed with hair growth stimulatory properties are prescribed with caution by oncologists. Hormones, growth factors, morphogens could unwontedly protect tumour cells or induce cancer cell proliferation and are thus considered incompatible with many chemotherapy regimens. Nutraceuticals, on the contrary, have been shown to be safe and effective treatment options for hair loss. We here show that polyphenols from Malus Pumila Miller cv Annurca are endowed with hair growth promoting activity and can be considered a safe alternative to avoid CIA. In vitro, Annurca Apple Polyphenolic Extract (AAE) protects murine Hair Follicles (HF) from taxanes induced dystrophy. Moreover, in virtue of its mechanism of action, AAE is herein proven to be compatible with chemotherapy regimens. AAE forces HFs to produce ATP using mitochondrial β-oxidation, reducing Pentose Phosphate Pathway (PPP) rate and nucleotides production. As consequence, DNA replication and mitosis are not stimulated, while a pool of free amino acids usually involved in catabolic reactions are spared for keratin production. Moreover, measuring the effect exerted on Poly Unsaturated Fatty Acid (PUFA) metabolism, we prove that AAE promotes hair-growth by increasing the intracellular levels of Prostaglandins F2α (PGF2α) and by hijacking PUFA catabolites toward β-oxidation.

Annurca Apple Polyphenols Ignite Keratin Production in Hair Follicles by Inhibiting the Pentose Phosphate Pathway and Amino Acid Oxidation

Patterned hair loss (PHL) affects around 50% of the adult population worldwide. The negative impact that this condition exerts on people’s life quality has boosted the appearance of over-the-counter products endowed with hair-promoting activity. Nutraceuticals enriched in polyphenols have been recently shown to promote hair growth and counteract PHL. Malus pumila Miller cv. Annurca is an apple native to Southern Italy presenting one of the highest contents of Procyanidin B2. We have recently shown that oral consumption of Annurca polyphenolic extracts (AAE) stimulates hair growth, hair number, hair weight and keratin content in healthy human subjects. Despite its activity, the analysis of the molecular mechanism behind its hair promoting effect is still partially unclear. In this work we performed an unprecedented metabolite analysis of hair follicles (HFs) in mice topically treated with AAE. The metabolomic profile, based on a high-resolution mass spectrometry approach, revealed that AAE re-programs murine HF metabolism. AAE acts by inhibiting several NADPH dependent reactions. Glutaminolysis, pentose phosphate pathway, glutathione, citrulline and nucleotide synthesis are all halted in vivo by the treatment of HFs with AAE. On the contrary, mitochondrial respiration, β-oxidation and keratin production are stimulated by the treatment with AAE. The metabolic shift induced by AAE spares amino acids from being oxidized, ultimately keeping them available for keratin biosynthesis.

Effect of Arthrospira (Spirulina) maxima Supplementation and a Systematic Physical Exercise Program on the Body Composition and Cardiorespiratory Fitness of Overweight or Obese Subjects: A Double-Blind, Randomized, and Crossover Controlled Trial

Excess weight and obesity are major risk factors for many chronic diseases, and weight-loss interventions often include systematic exercise and nutritional supplements. The purpose of this study was to determine the independent/synergistic effects of Arthrospira (Spirulina) maxima supplementation (six weeks, 4.5 g·day⁻¹) and a systematic physical exercise program (six weeks, twice weekly) on the body composition and cardiorespiratory fitness of overweight and obese subjects. To achieve this, 27 overweight and 25 obese sedentary male subjects were assigned to four interventions through a randomized double-blind, crossover controlled trial: A physical exercise program, with (SE) or without (Ex) Spirulina maxima; or no-exercise program, with (Sm) and without (C) Spirulina maxima. The body composition and cardiorespiratory fitness parameters were taken during a maximum intensity test. As compared to the C group, the body fat percentage of the SE, Sm and Ex groups was reduced (p < 0.05), while their maximal oxygen uptake improved (r = −0.40), and obese subjects benefited more significantly. Weight loss, the time to reach fatigue and the onset of blood lactate accumulation were improved in both of the Spirulina maxima supplemented groups, regardless of the subjects’ body weight. Spirulina maxima supplementation synergistically improves the effects of systematic exercise on body composition and cardiorespiratory fitness parameters in overweight, but mostly in individuals with obesity. Trial registration: Clinical Trials, NCT02837666. Registered 19 July 2016.