Activation of the human innate immune system by Spirulina: augmentation of interferon production and NK cytotoxicity by oral administration of hot water extract of Spirulina platensis

An attempt to induce an immunomodulatory effect in rowers with spirulina extract

Background

The aim of this study was to analyze the response of selected components of the immune system in rowers to maximal physical exercise, and to verify if this response can be modulated by supplementation with spirulina (cyanobacterium Spirulina platensis).

Method

The double-blind study included 19 members of the Polish Rowing Team. The subjects were randomly assigned to the supplemented group (n = 10), receiving 1500 mg of spirulina extract for 6 weeks, or to the placebo group (n = 9). The participants performed a 2000-m test on a rowing ergometer at the beginning (1st examination) and at the end of the supplementation period (2nd examination). Blood samples were obtained from the antecubital vein prior to each exercise test, 1 min after completing the test, and after a 24-h recovery period. Subpopulations of T regulatory lymphocytes (Tregs) [CD4+/CD25+/CD127-], cytotoxic lymphocytes (CTLs) [CD8+/TCRαβ+], natural killer (NK) cells [CD3-/CD16+/CD56+] and TCRδγ-positive (Tδγ) cells were determined by means of flow cytometry.

Results

On the 2nd examination, athletes from the supplemented group showed neither a post-exercise increase in Treg count nor a post-recovery decrease in Tδγ cell count (both observed in the placebo group), and presented with significantly lower values of Treg/CTL prior to and after the exercise. During the same examination, rowers from the placebo group showed a significant post-recovery increase in Treg/(NK + Tδγ + CTL) ratio, which was absent in the supplemented group.

Conclusion

The results of this study imply that supplementation with spirulina extract may protect athletes against a deficit in immune function (especially, anti-infectious function) associated with strenuous exercise, and may cause a beneficial shift in "overtraining threshold" preventing a radical deterioration of immunity.

Anti-inflammatory, antioxidant and antihepatotoxic effects of Spirulina platensis against d-galactosamine induced hepatotoxicity in rats

Spirulina platensis has been advocated as safe food for human use by several investigators. In this study its beneficial dietary effect against liver injuries caused by d-galactosamine (d-GalN) was studied ensuring safety to human health using animal model. Acute hepatotoxicity was induced in Wister rats with d-GalN followed by treatment with butylated hydroxytoluene (BHT) and with Spirulina aqueous extract at various concentrations. The effect of Spirulina at different concentrations were tried and compared with BHT treatment. The animals treated with d-GalN on subsequent treatment by supplementation with Spirulina (6, 9%) in the diets, led to significant reversal in the levels of the antioxidant enzymes through hepatocytes by suppression of negative effect. Spirulina aqueous extract at 9% resulted in a significant decrease in the levels of alkaline phosphatase and infalmatory markers TNFα, IL6 and IL1β and also decreased TBARS, while it showed an increase in oxidative stress marker such as GR, GSH, GST, SOD, GPX and CAT and total protein when compared to the levels recorded with that group treated with d-GalN. Results also indicated that Spirulina aqueous extract at 9% concentration was equally effective in protecting liver damage as it was observed with BHT. Histological studies on liver treated with d-GalN, BHT and Spirulina aqueous extract showed that S. platensis is effective as diet in providing beneficial protective effect. The results obtained in the present study very clearly indicated the positive beneficial protective effect of Spirulina, when used as diet, on the safety and protection of liver from injuries caused by toxicants.

Spirulina (Arthrospira platensis) supplementation improves growth performance, feed utilization, immune response, and relieves oxidative stress in Nile tilapia (Oreochromis niloticus) challenged with Pseudomonas fluorescens

One hundred and eighty Nile tilapia fish were used in eighty-three-day growth trial. Fish were divided into three treatment groups. The first group T0 was given the basal diet without any supplementation and served as the control group. The second group T1 was given the basal diet supplemented by 1% Spirulina. The third group T2 was given the basal diet supplemented by 2% Spirulina. At the end of the growth performance trial, a challenge trial was conducted using virulent strain of Pseudomonas fluorescens. Clinical signs, mortalities, postmortem lesions and histopathological alterations were recorded. Hematological, biochemical, oxidative stress and immunological parameters were measured after challenge with Pseudomonas fluorescens. Growth performance was non significantly improved in tilapia fed the diet with 1% Spirulina supplementation (T1). There were neither signs nor mortalities among fishes belonging to 1% Spirulina challenged group. The results showed that Spirulina has a positive effect on hematological, biochemical parameters, MDA, SOD and CAT at T1 (1% spirulia) rather than T2 (2%spirulia). Moreover, the results indicate that Spirulina 1% enhanced bactericidal, phagocytic and lysozyme activities conferring protection against infection. Our results demonstrated a significant up-regulation of pro-inflammatory cytokine (IL-1β and TNF-α) and a down-regulation of anti-inflammatory cytokine (IL-10). We concluded that 1% Spirulina supplementation significantly improved immunity of Nile tilapia against Pseudomonas fluorescence than 2% Spirulina supplementation.

Foodomics for human health: current status and perspectives

INTRODUCTION

In the post-genomic era, the opportunity to combine and integrate cutting-edge analytical platforms and data processing systems allowed the birth of foodomics, 'a discipline that studies the Food and Nutrition domains through the application of advanced omics technologies to improve consumer's well-being, health, and confidence'. Since then, this discipline has rapidly evolved and researchers are now facing the daunting tasks to meet consumers' needs in terms of food traceability, sustainability, quality, safety and integrity. Most importantly, today it is imperative to provide solid evidence of the mechanisms through which food can promote human health and well-being. Areas covered: In this review, the complex relationships connecting food, nutrition and human health will be discussed, with emphasis on the relapses for the development of functional foods and nutraceuticals, personalized nutrition approaches, and the study of the interplay among gut microbiota, diet and health/diseases. Expert commentary: Evidence has been provided supporting the role of various omic platforms in studying the health-promoting effects of food and customized dietary interventions. However, although associated to major analytical challenges, only the proper integration of multi-omics studies and the implementation of bioinformatics tools and databases will help translate findings from clinical practice into effective personalized treatment strategies.

Effect of Supercritical Carbon Dioxide Extraction Parameters on the Biological Activities and Metabolites Present in Extracts from Arthrospira platensis

Arthrospira platensis was used to obtain functional extracts through supercritical carbon dioxide extraction (SFE-CO₂). Pressure (P), temperature (T), co-solvent (CX), static extraction (SX), dispersant (Di) and dynamic extraction (DX) were evaluated as process parameters through a Plackett–Burman design. The maximum extract yield obtained was 7.48 ± 0.15% w/w. The maximum contents of bioactive metabolites in extracts were 0.69 ± 0.09 µg/g of riboflavin, 5.49 ± 0.10 µg/g of α-tocopherol, 524.46 ± 0.10 µg/g of β-carotene, 1.44 ± 0.10 µg/g of lutein and 32.11 ± 0.12 mg/g of fatty acids with 39.38% of palmitic acid, 20.63% of linoleic acid and 30.27% of γ-linolenic acid. A. platensis extracts had an antioxidant activity of 76.47 ± 0.71 µg GAE/g by Folin–Ciocalteu assay, 0.52 ± 0.02, 0.40 ± 0.01 and 1.47 ± 0.02 µmol TE/g by DPPH, FRAP and TEAC assays, respectively. These extracts showed antimicrobial activity against Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922 and Candida albicans ATCC 10231. Overall, co-solvent was the most significant factor for all measured effects (p < 0.05). Arthrospira platensis represents a sustainable source of bioactive compounds through SFE using the following extraction parameters P: 450 bar, CX: 11 g/min, SX: 15 min, DX: 25 min, T: 60 °C and Di: 35 g.

Monocyte chemoattractant protein-1 polymorphism interaction with spirulina immunomodulatory effects in healthy Korean elderly: A 16 week, double-blind randomized clinical trial

BACKGROUND/OBJECTIVES

Spirulina is a known a functional food related to lipid profiles, immune functions, and antioxidant capacity. Circulating monocyte chemoattractant protein-1 (MCP-1) level is associated with inflammation markers. Single nucleotide polymorphism in the MCP-1 promoter region -2518 have been identified and shown to affect gene transcription. Gene variation may also impact functional food supplementary effects. The current study investigated the interaction of MCP-1 -2518 polymorphism with spirulina supplements on anti-inflammatory capacity in Korean elderly.

SUBJECTS/METHODS

After genotyping, healthy elderly subjects (n = 78) were included in a randomized, double blind, and placebo controlled study. Baseline characteristic, body composition, and dietary intake were measured twice (baseline vs. week 16). For 16 weeks, subjects consumed 8 g either spirulina or placebo daily. Plasma MCP-1, interleukin (IL) -2, IL-6, tumor necrosis factor (TNF)-α, complement (C) 3, immunoglobulin (Ig) G, and Ig A concentrations and lymphocyte proliferation rate (LPR) were analyzed as inflammatory markers.

RESULTS

In the placebo group with A/A genotype, MCP-1 level was significantly increased, but the spirulina group with A/A genotype was unchanged. IL-2 was significantly increased only in subjects with spirulina supplementation. TNF-α was significantly reduced in subjects with the G carrier. C3 was significantly increased in the placebo group, particularly when A/A increased more than G, but not when spirulina was ingested. LPR was significantly different only in subjects with A/A genotype; there was a significant increase in phytohemagglutinin and lipopolysaccharide induced LPR in the spirulina group.

CONCLUSION

In healthy Korean elderly, spirulina supplementation may influence different inflammatory markers by the MCP-1 genotype. These results may be useful for customized dietary guidelines to improve immune function in Koreans.

Antioxidant, Immunomodulating, and Microbial-Modulating Activities of the Sustainable and Ecofriendly Spirulina

The highly nutritional and ecofriendly Spirulina (Arthrospira platensis) has hypolipidemic, hypoglycemic, and antihypertensive properties. Spirulina contains functional compounds, such as phenolics, phycocyanins, and polysaccharides, with antioxidant, anti-inflammatory, and immunostimulating effects. Studies conducted on Spirulina suggest that it is safe in healthy subjects, but attitude to eating probably affects the acceptability of Spirulina containing foods. Although the antioxidant effect of Spirulina is confirmed by the intervention studies, the concerted modulation of antioxidant and inflammatory responses, suggested by in vitro and animal studies, requires more confirmation in humans. Spirulina supplements seem to affect more effectively the innate immunity, promoting the activity of natural killer cells. The effects on cytokines and on lymphocytes' proliferation depend on age, gender, and body weight differences. In this context, ageing and obesity are both associated with chronic low grade inflammation, immune impairment, and intestinal dysbiosis. Microbial-modulating activities have been reported in vitro, suggesting that the association of Spirulina and probiotics could represent a new strategy to improve the growth of beneficial intestinal microbiota. Although Spirulina might represent a functional food with potential beneficial effects on human health, the human interventions used only supplements. Therefore, the effect of food containing Spirulina should be evaluated in the future.

Role of Spirulina in mitigating hemato-toxicity in Swiss albino mice exposed to aluminum and aluminum fluoride

Aluminum is ingested through foods, water, air, and even drugs. Its intake is potentiated further through foods and tea prepared in aluminum utensils and Al salt added in the drinking water for removal of suspended impurities and also fluoride in the affected areas. The ameliorating role of a blue green alga Spirulina is well documented to various pollutants in the animal models. We, therefore, examined its protective role (230 mg/kg body weight) on the hematology of male Swiss albino mice treated with aluminum (sub-acute = 78.4 mg/kg body weight for 7 days, sub-chronic = 7.8 mg/kg body weight for 90 days) and aluminum fluoride (sub-acute = 103 mg/kg body weight, sub-chronic = 21 mg/kg body weight), along with their recovery after 90 days of sub-chronic exposure. This study revealed significant reduction in the values of RBC (5-18 %), Hb (15-17 %), PCV (8-14 %), and platelets (26-36 %), and increase in WBC (54-124 %) in the treated mice, particularly after sub-acute exposure. Aluminum fluoride was comparatively more toxic than aluminum. Further, Spirulina supplement not only alleviated toxicity of test chemicals in Swiss albino mice but also led to their better recovery after withdrawal.

Microalgae Nutraceuticals

Among the new entries in the food supplements sector, an important place must be assigned to nutraceuticals containing microalgae, nowadays accounting for a large and rapidly expanding market. The marketed products are mainly based on three production strains, i.e., Spirulina and Chlorella, followed at a distance by Klamath. It is a composite situation, since two of them are cyanobacteria and the second one is eukaryotic. The reality is that each presents similarities in shape and appearance concerning the marketed form and several utilizations, and peculiarities that need special attention and adequate studies. First, general information is reported about the current scientific knowledge on each microalga, in particular the nutritional value and properties in prevention and wellbeing. Second, original studies are presented concerning the quality control of marketed products. Quality control is a key argument in nutraceuticals validation. Microalgae are particular organisms that need specific approaches to confirm identity and validate properties. The proposed control of quality is based on microscopic analysis of the morphologic characteristics. The final parts of this paper are dedicated to the need for specificity in uses and claims and to considerations about the future of microalgae in food supplements.

Neuroprotective effect of Arthrospira (Spirulina) platensis against kainic acid-neuronal death

Context Arthrospira (Spirulina) platensis (SP) is a cyanobacterium which has attracted attention because of its nutritional value and pharmacological properties. It was previously reported that SP reduces oxidative stress in the hippocampus and protects against damaging neurobehavioural effects of systemic kainic acid (KA). It is widely known that the systemic administration of KA induces neuronal damage, specifically in the CA3 hippocampal region. Objective The present study determines if the SP sub-chronic treatment has neuroprotective properties against KA. Materials and methods Male SW mice were treated with SP during 24 d, at doses of 0, 200, and 800 mg/kg, once daily, and with KA (35 mg/kg, ip) as a single dose on day 14. After the treatment, a histological analysis was performed and the number of atrophic neuronal cells in CA3 hippocampal region was quantified. Results Pretreatment with SP does not protect against seizures induced by KA. However, mortality in the SP 200 and the SP 800 groups was of 20%, while for the KA group, it was of 60%. A single KA ip administration produced a considerable neuronal damage, whereas both doses of SP sub-chronic treatment reduced the number of atrophic neurons in CA3 hippocampal region with respect to the KA group. Discussion The SP neurobehaviour improvement after KA systemic administration correlates with the capacity of SP to reduce KA-neuronal death in CA3 hippocampal cells. This neuroprotection may be related to the antioxidant properties of SP. Conclusion SP reduces KA-neuronal death in CA3 hippocampal cells.

Preclinical antitoxic properties of Spirulina (Arthrospira)

CONTEXT

Spirulina (Arthrospira) exerts a wide spectrum of pharmacological activities which are mainly attributed to its antioxidant effect. However, Spirulina has also been reported (both in preclinical and in clinical scenarios) to exhibit other bioactive effects, including an antitoxic potential.

OBJECTIVE

We performed a systematic review of the literature, conducted in TOXNET, PubMed/MEDLINE, and Science Direct-Scopus; all available years were included. Searching criteria included the effects of Spirulina on experimental poisonings from arsenic, cadmium, carbon tetrachloride, deltamethrin, fluoride, hexachlorocyclohexane, iron, lead, lindane, and mercury.

RESULTS

In all cases, it was established that the blue-green alga, and its isolated compounds, effectively counteracted these pollutants toxic effects on the exposed organisms. Some molecular mechanisms are proposed, although they have not been fully elucidated yet.

CONCLUSION

Spirulina could be a useful coadjuvant agent within clinical practice for treatment of these or other pollutants poisonings.

The antioxidant, immunomodulatory, and anti-inflammatory activities of Spirulina: an overview

Spirulina is a species of filamentous cyanobacteria that has long been used as a food supplement. In particular, Spirulina platensis and Spirulina maxima are the most important. Thanks to a high protein and vitamin content, Spirulina is used as a nutraceutical food supplement, although its other potential health benefits have attracted much attention. Oxidative stress and dysfunctional immunity cause many diseases in humans, including atherosclerosis, cardiac hypertrophy, heart failure, and hypertension. Thus, the antioxidant, immunomodulatory, and anti-inflammatory activities of these microalgae may play an important role in human health. Here, we discuss the antioxidant, immunomodulatory, and anti-inflammatory activities of Spirulina in both animals and humans, along with the underlying mechanisms. In addition, its commercial and regulatory status in different countries is discussed as well. Spirulina activates cellular antioxidant enzymes, inhibits lipid peroxidation and DNA damage, scavenges free radicals, and increases the activity of superoxide dismutase and catalase. Notably, there appears to be a threshold level above which Spirulina will taper off the antioxidant activity. Clinical trials show that Spirulina prevents skeletal muscle damage under conditions of exercise-induced oxidative stress and can stimulate the production of antibodies and up- or downregulate the expression of cytokine-encoding genes to induce immunomodulatory and anti-inflammatory responses. The molecular mechanism(s) by which Spirulina induces these activities is unclear, but phycocyanin and β-carotene are important molecules. Moreover, Spirulina effectively regulates the ERK1/2, JNK, p38, and IκB pathways. This review provides new insight into the potential therapeutic applications of Spirulina and may provide new ideas for future studies.

Well-tolerated Spirulina extract inhibits influenza virus replication and reduces virus-induced mortality

Influenza is one of the most common human respiratory diseases, and represents a serious public health concern. However, the high mutability of influenza viruses has hampered vaccine development, and resistant strains to existing anti-viral drugs have also emerged. Novel anti-influenza therapies are urgently needed, and in this study, we describe the anti-viral properties of a Spirulina (Arthrospira platensis) cold water extract. Anti-viral effects have previously been reported for extracts and specific substances derived from Spirulina, and here we show that this Spirulina cold water extract has low cellular toxicity, and is well-tolerated in animal models at one dose as high as 5,000 mg/kg, or 3,000 mg/kg/day for 14 successive days. Anti-flu efficacy studies revealed that the Spirulina extract inhibited viral plaque formation in a broad range of influenza viruses, including oseltamivir-resistant strains. Spirulina extract was found to act at an early stage of infection to reduce virus yields in cells and improve survival in influenza-infected mice, with inhibition of influenza hemagglutination identified as one of the mechanisms involved. Together, these results suggest that the cold water extract of Spirulina might serve as a safe and effective therapeutic agent to manage influenza outbreaks, and further clinical investigation may be warranted.

Role of pH on antioxidants production by Spirulina (Arthrospira) platensis

Algae can tolerate a broad range of growing conditions but extreme conditions may lead to the generation of highly dangerous reactive oxygen species (ROS), which may cause the deterioration of cell metabolism and damage cellular components. The antioxidants produced by algae alleviate the harmful effects of ROS. While the enhancement of antioxidant production in blue green algae under stress has been reported, the antioxidant response to changes in pH levels requires further investigation. This study presents the effect of pH changes on the antioxidant activity and productivity of the blue green alga Spirulina (Arthrospira) platensis. The algal dry weight (DW) was greatly enhanced at pH 9.0. The highest content of chlorophyll a and carotenoids (10.6 and 2.4mg/g DW, respectively) was recorded at pH 8.5. The highest phenolic content (12.1mg gallic acid equivalent (GAE)/g DW) was recorded at pH 9.5. The maximum production of total phycobiliprotein (159mg/g DW) was obtained at pH 9.0. The antioxidant activities of radical scavenging activity, reducing power and chelating activity were highest at pH 9.0 with an increase of 567, 250 and 206% compared to the positive control, respectively. Variation in the activity of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) was also reported. While the high alkaline pH may favor the overproduction of antioxidants, normal cell metabolism and membrane function is unaffected, as shown by growth and chlorophyll content, which suggests that these conditions are suitable for further studies on the harvest of antioxidants from S. platensis.

The search for a promising cell factory system for production of edible vaccine

Despite worldwide vaccination against devastating diseases for decades, millions of children in remote and impoverished regions of the globe die every year from vaccine-preventable infectious diseases. The reasons for incomplete coverage of vaccination programs are based in part on the relatively high costs of conventional vaccinations, including mass production, refrigeration, transportation, and training as well as funding personnel for their administration. Plant-based edible vaccines (PEVs) have been introduced as a revolutionary cost-effective vaccination modality. However, they suffer from major deficiencies that have restricted their application to bench-scale. This article discusses the deficiencies of PEVs and also provides concise overview on the health-promoting, biological and biotechnological features of spirulina (Arthrospira). In short, we envision that spirulina could be considered as a potential alternative biofactory system to the plants toward the production of edible vaccines in high-yield with low-costs that other hosts cannot yet offer.

Effect of dietary marine microalgae (schizochytrium) powder on egg production, blood lipid profiles, egg quality, and Fatty Acid composition of egg yolk in layers

Two hundred and sixteen Institut de Sélection Animale (ISA) brown layers (40 wks of age) were studied for 6 wks to examine the effect of microalgae powder (MAP) on egg production, egg quality, blood lipid profile, and fatty acid concentration of egg yolk. Dietary treatments were as follows: i) CON (basal diet), ii) 0.5% MAP (CON+0.5% Schizochytrium powder), and iii) 1.0% MAP (CON+1.0% Schizochytrium powder). From 44 to 46 wks, egg production was higher in 1.0% MAP treatment than in control treatment (linear, p = 0.034); however, there was no difference on the egg production from 40 to 43 wks (p>0.05). Serum triglyceride and total cholesterol were significantly reduced in the groups fed with MAP, compared to those in groups fed with control diets (Quadratic, p = 0.034 and p = 0.039, respectively). Inclusion of 0.5% MAP in the diet of layers improved egg yolk color, compared with hens fed with basal diet at 46 wks (quadratic, p = 0.044). Eggshell thickness was linearly increased in MAP-fed treatments at 46th wk (p<0.05). Concentration of yolk docosahexaenoic acid (DHA; C22:6n-3) was increased in treatment groups fed with MAP (linear, p<0.05). The n-6 fatty acids, n-6/n-3 fatty acid, and unsaturated fatty acid/saturated fatty acid were decreased in treatment groups fed with MAP (linear, p<0.05). These results suggest that MAP improved the egg production and egg quality, and may affect serum lipid metabolites in the layers. In addition, MAP increases yolk DHA levels, and deceases n-6/n-3 fatty acid ratio.

Biofunctionalized nanofibers using Arthrospira (Spirulina) biomass and biopolymer

Electrospun nanofibers composed of polymers have been extensively researched because of their scientific and technical applications. Commercially available polyhydroxybutyrate (PHB) and polyhydroxybutyrate-co-valerate (PHB-HV) copolymers are good choices for such nanofibers. We used a highly integrated method, by adjusting the properties of the spinning solutions, where the cyanophyte Arthrospira (formally Spirulina) was the single source for nanofiber biofunctionalization. We investigated nanofibers using PHB extracted from Spirulina and the bacteria Cupriavidus necator and compared the nanofibers to those made from commercially available PHB and PHB-HV. Our study assessed nanofiber formation and their selected thermal, mechanical, and optical properties. We found that nanofibers produced from Spirulina PHB and biofunctionalized with Spirulina biomass exhibited properties which were equal to or better than nanofibers made with commercially available PHB or PHB-HV. Our methodology is highly promising for nanofiber production and biofunctionalization and can be used in many industrial and life science applications.

Prospects of geothermal water Use in cultivation of Spirulina

Spirulina has been studied due to its commercial importance as a source of essential amino acids, protein, vitamins, fatty acids etc. Most of the culture systems in use today are open ponds. The new approach proposed in this paper is to use the geothermal water as a medium for microalgae cultivation. Poland has beneficial conditions for wide geothermal use, as one of the environmentally friendly and sustainable renewable energy sources. In the planned research, geothermal water could be used to prepare microalgal culture medium, to heat greenhouses with bioreactors used for the growth of Spirulina, to dry the obtained biomass, as well as to heat the ground in foil tunnels. Using geothermal water gives the possibility to produce algae in open ponds covered with greenhouses and to cultivate plants during winter. The obtained algae can be used for the production of algal bio-products (e.g. homogenates), having the potential application in plant cultivation.

Biological effects of Spirulina (Arthrospira) biopolymers and biomass in the development of nanostructured scaffolds

Spirulina is produced from pure cultures of the photosynthetic prokaryotic cyanobacteria Arthrospira. For many years research centers throughout the world have studied its application in various scientific fields, especially in foods and medicine. The biomass produced from Spirulina cultivation contains a variety of biocompounds, including biopeptides, biopolymers, carbohydrates, essential fatty acids, minerals, oligoelements, and sterols. Some of these compounds are bioactive and have anti-inflammatory, antibacterial, antioxidant, and antifungal properties. These compounds can be used in tissue engineering, the interdisciplinary field that combines techniques from cell science, engineering, and materials science and which has grown in importance over the past few decades. Spirulina biomass can be used to produce polyhydroxyalkanoates (PHAs), biopolymers that can substitute synthetic polymers in the construction of engineered extracellular matrices (scaffolds) for use in tissue cultures or bioactive molecule construction. This review describes the development of nanostructured scaffolds based on biopolymers extracted from microalgae and biomass from Spirulina production. These scaffolds have the potential to encourage cell growth while reducing the risk of organ or tissue rejection.

Supercritical CO2 extraction of functional compounds from Spirulina and their biological activity

Supercritical carbon dioxide (SCCO2) extraction and fractionation of Spirulina platensis was carried out to obtain functional compounds with antioxidant, antimicrobial and enzyme inhibitory activities. Extraction of SCCO2 was carried out using 200 g of Spirulina powder at 40 ºC under 120 bar pressure with CO2 flow rate of 1.2 kg h(-1). SCCO2 fraction obtained was further treated with hexane and ethyl acetate to identify its components. Individual components were identified by comparing mass spectra of samples with standard data and retention indices (RI) of C5-C20 n-alkanes mixture using the kovat index formula. The phenolic and flavonoid content of the SCCO2 extract was found to be 0.34 ± 0.01 g/100 g and 0.12 ± 0.01 g/100 g respectively. The SCCO2 extract had antioxidant activity with IC50 value of 109.6 ± 3.0 μg mL(-1) for DPPH (2,2-Diphenyl-1-picryl hydrazyl radical), IC50 value of 81.66 ± 2.5 μg mL(-1) for reducing power and IC50 value of 112.70 ± 0.8 μg mL(-1) for hydroxyl radical scavenging activity. Further, antioxidant activity study on oxidative induced DNA damage was analysed to elucidate the positive role of SCCO2 extract. SCCO2 extracts showed high antimicrobial activity against Gram-positive bacteria (Staphylococcus aureus FRI 722 and Bacillus cereus F 4810) compared to that of Gram negative bacteria (Escherichia coli MTCC 108 and Yersinia enterocolitica MTCC 859). The SCCO2 extract exhibited inhibitory activity on both Angiotensin-1 converting enzyme and α-glucosidase with IC50 values of 274 ± 1.0 μg mL(-1) and 307 ± 2.0 μg mL(-1) respectively.

Hepatoprotective effect of germanium-containing Spirulina in rats with d-galactosamine- and lipopolysaccharide-induced hepatitis

In the present study, the protective effects of dietary Spirulina (SP) and germanium-containing Spirulina (GeSP) were compared in rats with liver injury induced by an intraperitoneal injection of d-galactosamine and lipopolysaccharide (GalN/LPS). Wistar rats were fed one of the following diets: the basal diet (GalN/LPS-CON group; n 6), the basal diet supplemented with 5 % SP or GeSP (GalN/LPS-SP and GalN/LPS-GeSP group, respectively; n 7 each). After administering these diets for 7 d, each rat was intraperitoneally injected with GalN/LPS. Increases in plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities were suppressed in the GalN/LPS-GeSP group (GalN/LPS-CON v. GalN/LPS-GeSP: ALT 1052 (sem 187) v. 509 (sem 88) IU/l and AST 2183 (sem 368) v. 1170 (sem 196) IU/l) following the injection of GalN/LPS. Plasma levels of interferon-γ (IFN-γ) and TNF-α in GeSP-fed rats were significantly lower when compared with those in the GalN/LPS-CON group (GalN/LPS-CON v. GalN/LPS-GeSP: IFN-γ 142·8 (sem 17·5) v. 66·8 (sem 9·7) pg/ml and TNF-α 72·3 (sem 15·4) v. 31·2 (sem 6·8) pg/ml). However, the decrease in these levels observed in the GalN/LPS-SP group was not as prominent as those observed in the GalN/LPS-GeSP group. Furthermore, the increase in liver catalase (CAT) and glutathione peroxidase (GPx) activities, as well as the level of oxidised glutathione (GSSG), was more suppressed in GeSP-fed rats (GalN/LPS-CON v. GalN/LPS-GeSP: CAT 457 (sem 47) v. 262 (sem 54) U/mg liver protein; GPx 1·30 (sem 0·11) v. 0·53 (sem 0·09) U/mg liver protein; GSSG 2·18 (sem 0·33) v. 1·31 (sem 0·24) mmol/kg liver) after the injection of GalN/LPS. These changes were more pronounced in the GalN/LPS-GeSP group than in the GalN/LPS-SP group. These results suggest that GeSP could afford a significant protective effect in the alleviation of GalN/LPS-induced hepatic damage. In addition, the results indicate that GeSP is more effective than SP.

Enhancement of immune activation activities of Spirulina maxima grown in deep-sea water

In this study, the immuno-modulatory and anticancer activities of marine algae, Spirulina maxima grown in deep-sea water (DSW), were investigated. It was found that the extract of S. maxima, cultured in DSW, effectively suppressed the expression of Bcl2 in A549 cells as well as inhibiting various human cancer cells with concentration dependency, which possibly implies that the extracts may play more important roles in controlling cancer cell growth. The secretion of cytokines IL-6 and TNF-α from human B cells was also greatly increased, compared to those of the extract grown in conventional sea-water. The growth of Human Natural Killer (NK) cells in the presence of the extracts from DSW was significantly higher (12.2 × 104 viable cells/mL) when compared to the control (1.1 × 104 viable cells/mL). Based on HPLC analysis, the increase in the biological activities of the extracts from DSW was caused by considerably high amounts of β-carotene and ascorbic acid because the DSW contained high concentrations and good ratios of several key minerals for biosynthesizing β-carotene and ascorbic acid, as well as maintaining high cell growth.

Spirulina platensis versus silymarin in the treatment of chronic hepatitis C virus infection. A pilot randomized, comparative clinical trial

Background

Spirulina platensis, a cynobacterium used frequently as a dietary supplement had been found to exhibit many immune-stimulating and antiviral activities. It had been found to activate macrophages, NK cells, T cells, B cells, and to stimulate the production of Interferon gamma (IFN-γ) and other cytokines. Natural substances isolated from Spirulina platensis had been found to be potent inhibitors against several enveloped viruses by blocking viral absorption/penetration and some replication stages of progeny viruses after penetration into cells. We aimed to study whether this dietary supplement possesses any therapeutically feasible activity worthy of further larger controlled clinical evaluation.

Methods

Sixty six patients with chronic hepatitis C virus infection and eligible for inclusion had been randomized to either Spirulina or Silymarin treated groups for a period of six months treatment.

The two groups were followed up and blindly compared for early (after 3 months) and end of 6 months treatment virological response. The effects of both treatments on each of alanine aminotransferase (ALT), Chronic Liver Disease Questionnaire scores (CLDQ), Arizona Sexual Experience Scale scores (ASEX) and the occurrence of any attributable adverse events were also compared.

Results

Among the 30 patients who had been treated with Spirulina and completed the 6 months protocol, 4 patients (13.3%) had a complete end of treatment virological response and 2 patients (6.7%) had a partial end of treatment response defined as significant decrease of virus load of at least 2-logs₁₀. Though the proportion of responders in Spirulina group was greater than in the Silymarin group, the difference was not statistically significant at the end of both 6 months (p = 0.12) and 3 months treatment (p = 0.22) by Exact test. Alanine aminotransferase as well as CLDQ and ASEX scores were found to be more significantly improved in Spirulina than in Silymarin treated group.

Conclusions

Our results could suggest a therapeutically feasible potential for Spirulina platensis in chronic HCV patients, worthy to conduct a larger sized and longer study to confirm these safety and efficacy encouraging results.

Trial Registration

WHO Clinical Trial Registration ID: ACTRN12610000958088

http://apps.who.int/trialsearch/trial.aspx?trialid=ACTRN12610000958088

Comparison of the therapeutic effects of extracts from Spirulina platensis and amnion membrane on inflammation-associated corneal neovascularization

AIM

To compare the therapeutic effects of polysaccharide extract from Spirulina platensis (PSP) and extract from amnion membrane (AME) on alkali burn-induced corneal neovascularization (CorNV).

METHODS

PSP and AME were extracted from dry powder of Spirulina platensis and human aminion membrane respectively. Murine CorNV was induced by applying 1N sodiumhydroxide (NaOH) solution directly on the mice corneas. PSP and AME extracts were administered topically on the corneas 4 times daily for 7 days. The therapy effects of PSP and AME extracts were evaluated daily using slit-lamp. At the end of the therapy, corneas were harvested for H&E staining, masson trichrome staining, immunohistochemical study, and semi-quantification reverse transcriptive PCR (RT-PCR) was utilized for measurement of inflammation-related molecules.

RESULTS

Topical application of PSP extract had significant therapeutic effects on CorNV that could be shown in various assays of the corneas. Compared with AME extract, PSP extract treatment was more effective in suppressing CorNV in terms of vessel length and levels of cluster of differentiation 31 (CD31) proteins or the angiogenesis related genes like vascular endothelial growth factor (VEGF), matrix metalloproteinase-2 (MMP2) and matrix metalloproteinase-9 (MMP9). PSP also inhibited inflammation more markedly by more effectively inhibiting mononuclear and polymorphonuclear cells infiltration into the corneal stroma and reducing levels of stromal cell-derived factor-1 (SDF1), tumor necrosis factor-alpha (TNFα) and macrophage inflammatory protein-3 (MIP3a). In additon, corneas of PSP group had a more regular and compact architecture of collagen with thinner corneal thickness than in the AME group.

CONCLUSION

Polysaccharide extract from Spirulina platensis inhibited alkali burn-induced inflammation and CorNV more effectively than AME extract at the studied doses, thus may be used for the therapy of corneal diseases involving neovascularization and inflammation.

In vitro evaluation of the effects of electrospun PCL nanofiber mats containing the microalgae Spirulina (Arthrospira) extract on primary astrocytes

The blue-green microalgae, Spirulina, a harmless food and pharmaceutical additive, has several bioactive compounds that have therapeutic functions. Polycaprolactone (PCL) is a biocompatible and biodegradable polymer that has widely been used for tissue engineering. The electrospun PCL nanofiber containing Spirulina (PCL-Spirulina) was fabricated and tested as a potential extracellular matrix material for a culture of primary astrocytes, which play important roles in CNS injured systems. Spirulina extract was observed to increase growth and metabolic activity of rat primary astrocytes without any harm once added to the culture media. However, PCL-Spirulina nanofiber was proven to alleviate astrocyte activity. Through this research and to the best of our knowledge, we first suggest a novel composite nanomaterial, an electrospun PCL-Spirulina nanofiber that could be used to treat CNS injured systems.

Immunology and probiotic impact of the newborn and young children intestinal microflora

Human body has developed a holistic defence system, which mission is either to recognize and destroy the aggressive invaders or to evolve mechanisms permitting to minimize or restore the consequences of harmful actions. The host immune system keeps the capital role to preserve the microbial intestinal balance via the barrier effect. Specifically, pathogenic invaders such as, bacteria, parasites, viruses and other xenobiotic invaders are rejected out of the body via barriers formed by the skin, mucosa and intestinal flora. In case physical barriers are breached, the immune system with its many components comes into action in order to fence infection. The intestine itself is considered as an "active organ" due to its abundant bacterial flora and to its large metabolic activity. The variation among different species or even among different strains within a species reflects the complexity of the genetic polymorphism which regulates the immune system functions. Additionally factors such as, gender, particular habits, smoking, alcohol consumption, diet, religion, age, gender, precedent infections and vaccinations must be involved. Hormonal profile and stress seems to be associated to the integrity microbiota and inducing immune system alterations. Which bacterial species are needed for inducing a proper barrier effect is not known, but it is generally accepted that this barrier function can be strongly supported by providing benefic alimentary supplements called functional foods. In this vein it is stressed the fact that early intestinal colonization with organisms such as Lactobacilli and Bifidobacteria and possibly subsequent protection from many different types of diseases. Moreover, this benefic microflora dominated but Bifidobacteria and Lactobacilli support the concept of their ability to modify the gut microbiota by reducing the risk of cancer following their capacity to decrease β-glucoronidase and carcinogen levels. Because of their beneficial roles in the human gastrointestinal tract, LAB are referred to as "probiotics", and efforts are underway to employ them in modern nutrition habits with so-called functional foods. Members of Lactobacillus and Bifidobacterium genera are normal residents of the microbiota in the human gastrointestinal tract, in which they developed soon after birth. But, whether such probiotic strains derived from the human gut should be commercially employed in the so-called functional foods is a matter of debate between scientists and the industrial world. Within a few hours from birth the newborn develops its normal bacterial flora. Indeed human milk frequently contains low amounts of non-pathogenic bacteria like Streptococcus, Micrococcus, Lactobacillus, Staphylococcus, Corynebacterium and Bifidobacterium. In general, bacteria start to appear in feces within a few hours after birth. Colonization by Bifidobacterium occurs generally within 4 days of life. Claims have been made for positive effects of Bifidobacterium on infant growth and health. The effect of certain bacteria having a benefic action on the intestinal ecosystem is largely discussed during the last years by many authors. Bifidobacterium is reported to be a probiotic bacterium, exercising a beneficial effect on the intestinal flora. An antagonism has been reported between B. bifidum and C. perfringens in the intestine of newborns delivered by cesarean section. The aim of the probiotic approach is to repair the deficiencies in the gut flora and restore the protective effect. However, the possible ways in which the gut microbiota is being influenced by probiotics is yet unknown.

Spirulina in clinical practice: evidence-based human applications

Spirulina or Arthrospira is a blue-green alga that became famous after it was successfully used by NASA as a dietary supplement for astronauts on space missions. It has the ability to modulate immune functions and exhibits anti-inflammatory properties by inhibiting the release of histamine by mast cells. Multiple studies investigating the efficacy and the potential clinical applications of Spirulina in treating several diseases have been performed and a few randomized controlled trials and systematic reviews suggest that this alga may improve several symptoms and may even have an anticancer, antiviral and antiallergic effects. Current and potential clinical applications, issues of safety, indications, side-effects and levels of evidence are addressed in this review. Areas of ongoing and future research are also discussed.

Activation of porcine natural killer cells and lysis of foot-and-mouth disease virus infected cells

Natural killer (NK) cells play a vital role in innate response against viral infections and cellular transformation. In vivo modulation of their response may enhance their antiviral function. Here we describe the phenotype of porcine NK cells, test potential proinflammatory cytokines for activation of these cells and assess the capability of porcine NK cells to kill virus-infected or tumor cells in vitro. The CD2+/CD8+/CD3(-) cell compartment contained porcine NK cells, which at the resting stage were minimally cytotoxic toward foot-and-mouth disease virus (FMDV)-infected porcine cells or tumor cell lines. Direct stimulation of NK cells with proinflammatory cytokines induced efficient lysis of FMDV-infected cells with interleukin (IL)-2 or IL-15 showing the highest stimulatory capacity. Lower levels of NK cell activation were induced by IL-12, IL-18, or interferon (IFN)-alpha, however, IL-12 and IL-18 synergistically activated NK cells. Combinations of IL-15 and IL-12 or IL-15 and IL-18 did not further increase the porcine NK cell lytic capability over IL-15 alone. Natural killer cells expressed IFN-gamma regardless of the cytokine used for stimulation while expression of perforin increased modestly. The enhancement of porcine NK cell activity by proinflammatory cytokines offers a promising tool for development of antiviral approaches against virus infection.

Characterization of microalgal carotenoids by mass spectrometry and their bioavailability and antioxidant properties elucidated in rat model

Of the total carotenoids in respective algal samples, beta-carotene in Spirulina platensis was 69.5%, astaxanthin and its esters in Haematococcus pluvialis was 81.38%, and lutein in Botryococcus braunii was 74.6%. The carotenoids were characterized by mass spectrometry. A time-course study of carotenoids in rats after administration of microalgal biomass showed peak levels in plasma, liver, and eyes at 2, 4, and 6 h, respectively. Beta-carotene accumulation in Spirulina-fed rats was maximum in eye tissues at 6 h. Similarly, levels of astaxanthin and lutein in Haematococcus- and Botryococcus-fed rats were also maximal in eye tissues. Astaxanthin from H. pluvialis showed better bioavailability than beta-carotene and lutein. The antioxidant enzymes, catalase, superoxide dismutase, peroxidase, and TBARS were significantly high in plasma at 2 h and in liver at 4 h, evidently offering protection from free radicals. This study implies that microalgae can be a good source of carotenoids of high bioavailability and nutraceutical value.

Isolation of an antihypertensive peptide from alcalase digest of Spirulina platensis

An angiotensin I-converting enzyme (ACE) inhibitory peptide Ile-Gln-Pro with an IC(50) value of 5.77 +/- 0.09 microM was purified from the alcalase digests of Spirulina platensis by gel filtration chromatography and two steps of reverse-phase high-performance liquid chromatography (RP-HPLC). The peptide was synthesized and showed resistance to in vitro digestion by gastrointestinal proteases. Kinetics studies indicated that the peptide was a noncompetitive inhibitor and that the K(i) value was 7.61 +/- 0.16 microM. Oral administration of Ile-Gln-Pro at a dosage of 10 mg/kg showed significant decreases of the weighted systolic blood pressure (SBP) and diastolic blood pressure (DBP) in spontaneously hypertensive rats (SHR) at 4, 6, and 8 h after treatment. The results showed that the ACE inhibitory peptide from Spirulina platensis may have potential for use in the prevention and treatment of hypertension.

Protection by dietary Spirulina platensis against D-galactosamine--and acetaminophen-induced liver injuries

Increasing attention has been paid to Spirulina for its potential clinical uses. The present study investigated the protection by dietary Spirulina platensis against d-galactosamine (d-GalN)- and acetaminophen (APAP)-induced hepatitis in ICR mice. Mice in each group (n 6) were fed with a standard diet (American Institute of Nutrition (AIN)-93G), a positive control diet containing 0.5 % butylated hydroxytoluene (BHT), or a diet containing 3, 6 or 9 % S. platensis for 1 week. On the last day the mice were treated with d-GalN (300 mg/kg body weight, intraperitoneally) or APAP (150 mg/kg body weight, intraperitoneally) and 24 h later the mice were killed. The doses of both 6 and 9 % S. platensis were found to significantly alleviate the increase of serum glutamate oxaloacetoacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT) activities in d-GalN- or APAP-intoxicated mice. The observation was very similar to that of the positive control groups. Two more experiments were carried out to investigate the involvement of thiobarbituric acid-reactive substances (TBARS) and IL-18 in the suppression of 6 % S. platensis on d-GalN- and APAP-induced hepatitis. The significant increase of GOT and GPT activities was found to be accompanied with the elevation of hepatic TBARS level, IL-18 mRNA expression and serum IL-18 concentration, and was significantly alleviated by supplementation with 6 % S. platensis in diets. These results showed that dietary S. platensis could provide a significant protection against d-GalN- and APAP-induced liver injuries, and IL-18 and lipid peroxidation might be involved in the protective influence of S. platensis.

Enhancement of antitumor natural killer cell activation by orally administered Spirulina extract in mice

Oral administration of hot-water extract of Spirulina, cyanobacterium Spirulina platensis, leads to augmentation of NK cytotoxicity in humans. Here, we applied to syngeneic tumor-implant mice (C57BL/6 versus B16 melanoma) Spirulina to elucidate the mechanism of raising antitumor NK activation. A B16D8 subcell line barely expressed MHC class I but about 50% expressed Rae-1, a ligand for NK activation receptor NKG2D. The Rae-1-positive population of implant B16 melanoma was effectively eliminated in the tumor mass progressed in mice. This antitumor activity was induced in parallel with IFN-gamma and abolished in mice by treatment with asialoGM-1 but not CD8beta Ab, suggesting the effector is NK cell. NK cell activation occurred in the spleen of wild-type mice medicated with Spirulina. This Spirulina-mediated enhanced NK activation was abrogated in MyD88 -/- mice but not in TICAM-1 -/- mice. The NK activating properties of Spirulina depending on MyD88 were confirmed with in vitro bone marrow-derived dendritic cells expressing TLR2/4. In D16D8 tumor challenge studies, the antitumor effect of Spirulina was abolished in MyD88 -/- mice. Hence, orally administered Spirulina enhances tumoricidal NK activation through the MyD88 pathway. Spirulina exerted a synergistic antitumor activity with BCG-cell wall skeleton, which is known to activate the MyD88 pathway via TLR2/4 with no NK enhancing activity. Spirulina and BCG-cell wall skeleton synergistically augmented IFN-gamma production and antitumor potential in the B16D8 versus C57BL/6 system. We infer from these results that NK activation by Spirulina has some advantage in combinational use with BCG-cell wall skeleton for developing adjuvant-based antitumor immunotherapy.