Preclinical antitoxic properties of Spirulina (Arthrospira)

Spirulina/Arthrospira/Limnospira-Three Names of the Single Organism

Recent advances in research techniques have enabled rapid progress in the study of spirulina, an ancient edible cyanobacteria. Nowadays, spirulina species are classified into three genera: Spirulina, Arthrospira, and Limnospira. The latter now refers to industrially manufactured spirulina strains. Whole-genome sequencing revealed gene clusters involved in metabolite production, and the physiology of spirulina. Omics technologies demonstrated the absence of hazardous compounds in spirulina cells, confirming the safety of this biomass as a food product. Spirulina is a good source of different chemicals used in food manufacturing, food supplements, and pharmaceuticals. Spirulina's enrichment with inherent biologically active substances makes it a potential supplier of natural products for dietary and pharmaceutical applications. Spirulina is also a prospective component of both terrestrial and space-based life support systems. Here, we review current breakthroughs in spirulina research and clarify fallacies that can be found in both professional literature and public media.

Phytochemicals Involved in Mitigating Silent Toxicity Induced by Heavy Metals

Heavy metals (HMs) are natural elements present in the Earth's crust, characterised by a high atomic mass and a density more than five times higher than water. Despite their origin from natural sources, extensive usage and processing of raw materials and their presence as silent poisons in our daily products and diets have drastically altered their biochemical balance, making them a threat to the environment and human health. Particularly, the food chain polluted with toxic metals represents a crucial route of human exposure. Therefore, the impact of HMs on human health has become a matter of concern because of the severe chronic effects induced by their excessive levels in the human body. Chelation therapy is an approved valid treatment for HM poisoning; however, despite the efficacy demonstrated by chelating agents, various dramatic side effects may occur. Numerous data demonstrate that dietary components and phytoantioxidants play a significant role in preventing or reducing the damage induced by HMs. This review summarises the role of various phytochemicals, plant and herbal extracts or probiotics in promoting human health by mitigating the toxic effects of different HMs.

Effect of Spirulina (Formerly Arthrospira) Maxima against Ethanol-Induced Damage in Rat Liver

Spirulina (formerly Arthrospira) maxima (SP) is a cyanobacterium reported to have great nutritional and pharmacological potential. The objective of this study was to evaluate the protective properties of SP against ethanol-induced toxicity. Male Wistar rats were used in the study and subjected to a 70% partial hepatectomy (PH); they were then divided into five groups. During the experiment, animals in two groups drank an aqueous solution of ethanol (EtOH) (40%, v/v). Additionally, they were administered an SP extract daily at a dose of 200 mg/kg body weight intragastrically. To explore possible mechanisms of action, we examined antioxidant defense enzymes, as well as serum biochemical parameters and histopathological changes in the liver. SP administration normalized elevated glutathione reductase (GR), glutathione (GSH), and superoxide dismutase (SOD) levels, in addition to increased catalase (CAT) and glutathione peroxidase (GPX) enzymes. Alterations in biochemical parameters were observed in the groups with PH treated with EtOH associated with a reduction in cholesterol and albumin levels, while glucose and triglyceride levels increased. The histological study supported the protective activity of SP, reducing apoptosis, necrosis, and congestion in the liver. Our findings demonstrated a protective effect of SP against EtOH that is related to less inflammation, a lesser antioxidant effect, and less free radical scavenging activity.

Effects From Dietary Addition of Sargassum sp., Spirulina sp., or Gracilaria sp. Powder on Immune Status in Broiler Chickens

Algae are innovative and significant nutrient sources with various health benefits when used as additives in animal feed. The study aims to examine the effect of different inclusions of three algae species, Sargassum sp., Spirulina sp., and Gracilaria sp. on the immune response of broiler chickens, as measured by the cellular immune response, humoral immune response, intestinal microbial counts, hindgut acidosis, and hematological measures. Here is a list of the seven experimental treatments (TRT). TRT 1 was the control group without algae; TRT 2 was supplemented with Sargassum sp. at 1% of the diet; TRT 3 with Sargassum sp. at 2% of the diet; TRT 4 with Spirulina sp. at 5% of the diet; TRT 5 with Spirulina sp. at 7.5% of the diet; TRT 6 with Gracilaria sp. at 0.5% of the diet; and TRT 7 Gracilaria sp. at 1% of the diet. Each treatment involved five replicates with 17 broiler chickens each, and the analyses were triplicated. The results showed that including algae in the feed ration of broiler chickens induces a higher cellular response than the control group, represented by T-cell response in the wattle area (P = 0.037). Sargassum sp. at 1 and 2% enhanced IgA antibody titers significantly and Gracilaria sp. at 5% enhanced IgY antibody titers, P = 0.045 and P = 0.030, respectively. All algal inclusions inhibited the growth of Salmonella sp. and improved LAB counts in the intestine of broilers, excepting the Gracilaria sp. at 0.5%, where LAB counts were similar to the control group. The E. coli counts decreased numerically but not significantly. Blood lymphocytes were enhanced while white blood cells (WBC) and heterophils were decreased as a results of algal inclusions. In conclusion, supplementing broiler chickens with algae could enhance their cellular and humoral immune status and promote healthy microflora in their guts.

Preparation, Characterization, and Antioxidant Properties of Phycocyanin Complexes Based on Sodium Alginate and Lysozyme

In this study, phycocyanin-sodium alginate/lysozyme complex (PC-SLC) was prepared for the first time and characterized by UV spectroscopy, Fourier transform infrared spectroscopy (FT-IR), and circular dichroism spectroscopy (CD). The stability of PC-SLC under light, temperature, pH and simulated gastrointestinal fluid was investigated. The scavenging ability of the complexes against DPPH and ABTS radicals was determined. The results showed that the complex formed by the mass ratio of SA-LZM of 0.1 showed the highest PC encapsulation rate (89.9 ± 0.374%). The combination of SA and LZM changed the secondary conformation of PC. The PC-SLC complex shows an irregular spherical structure and the spheres are clustered together. Compared with phycocyanin (PC), its thermal stability was obviously improved, but it was still greatly influenced by light. It could exist stably in simulated gastric fluid (SGF) for 2 h and be slowly digested in simulated intestinal fluid (SIF), which helped to promote the absorption of nutrients in the intestinal tract. Meanwhile, the complex PC-SLC showed high scavenging ability for DPPH and ABTS radicals. It can be concluded that the complexes have good antioxidant activity. This study provides an idea for the construction of PC delivery system and makes it more widely used in food industry and other fields.

Uma revisão de escopo de revisões sistemáticas sobre exposição humana ao mercúrio

Resumo: Introdução: a promulgação da Convenção de Minamata no Brasil em 2018 incentivou o cumprimento dos seus objetivos em reduzir o uso e a poluição por mercúrio. Objetivo: caracterizar a produção científica sobre exposição humana ao mercúrio e identificar lacunas de conhecimento a fim de subsidiar a tomada de decisão em saúde. Métodos: revisão de escopo de revisões sistemáticas e metanálises, sem restrição de idioma ou data de publicação, utilizando as bases PubMed, BVS e Cochrane Library. Resultados: 71 estudos atenderam aos critérios de elegibilidade, com 40 revisões sistemáticas, 30 metanálises e 1 overview. Amálgama dentário e contaminação alimentar e ambiental por atividades que utilizam mercúrio foram as fontes de exposição mais mencionadas. Os temas mais estudados contaram com transtornos mentais e comportamentais, assim como uso de biomarcadores e testes neurocomportamentais relacionados à exposição ao mercúrio. Discussão: lacunas como a exposição ocupacional ao mercúrio, uso em práticas tradicionais e em cosméticos apontam para a necessidade de mais estudos. As revisões identificadas podem oferecer subsídios para sínteses de evidências e protocolos de atenção à saúde de populações expostas, assim como para a elaboração de políticas públicas que visem o controle do uso e da exposição ao mercúrio.

Arthrospira platensis accelerates the formation of an endothelial cell monolayer and protects against endothelial cell detachment after bacterial contamination

Within the last years a comprehensive number of scientific studies demonstrated beneficial effect of Arthropira platensis (AP) as dietary supplement due to a high content of proteins, minerals and vitamins. Positive effects like promoting the immune system, reducing inflammation and an anti-oxidant capacity are reported. In this study, the effect of an aqueous AP extract on primary human venous endothelial cells (HUVEC) was investigated. In addition, the effect of AP on HUVEC treated with a bacterial toxin (lipopolysaccharide, LPA), inducing an activation of HUVEC and cellular detachment, was analyzed. Depending on the concentration of AP extract a significantly accelerated formation of an endothelial cell monolayer was observed. Furthermore, the detachment of HUVEC after LPA addition was dramatically reduced by AP. In conclusion, the data are promising and indicatory for an application of Arthrospira platensis in the clinical field.

Physicochemical Evaluation of Edible Cyanobacterium Arthrospira platensis Collected from the South Atlantic Coast of Morocco: A Promising Source of Dietary Supplements

The cyanobacterium Arthrospira platensis (A. platensis)—a genus of nonheterocystous filamentous cyanobacteria—is used in industrial applications and as a food supply. The current research work aims to study the physicochemical characteristics of A. platensis indigenous to the Moroccan Atlantic coast at Laayoune (Foum El Oued lagoon). The contents of proteins, carbohydrates, vitamins, lipids, minerals, heavy metals, energy value, humidity, ash, pigments, and tannins in A. platensis were investigated using protocols as described in the earlier literature. The values of protein, carbohydrate, and lipid contents in A. platensis were 58.9 ± 0.07, 14.67, and 45.54% respectively. The values of vitamins B₂ and B₃ dosed in A. platensis were 1.31 ± 0.19 and 30.8 ± 0.001 mg/kg, respectively. The values of heavy metals including lead and chromium were 70 ± 4.5 and 5 ± 0.5 PPB (parts-per-billion), respectively; however, no trace concerning cadmium was detected. The values of energy value, humidity, and ash content were 346.48 ± 0.21, 11.6 ± 0.17%, and 9.1 ± 0.21% kcal/100 g, respectively. The results of pigment content showed the presence of chlorophyll b, chlorophyll a, and carotenoids of 37.506 ± 3.38, 26.066 ± 3.08, and 9.52 ± 0.22 mg/g, respectively. The results obtained revealed that A. platensis indigenous to the Moroccan Atlantic coast at Laayoune was found to be very rich in proteins, carbohydrates, vitamins, minerals, ash, and pigments and lower in heavy metals and saturated fats when compared with species investigated in the literature. Thus, A. platensis indigenous to the Moroccan Atlantic coast at Laayoune fulfills the requirements for being used as dietary supplements.

Oxy+ (arthrospira) and its medicinal importance: an appraisal

Oxy+ is a natural source of arthrospira found in nature, used as a dietary supplement and manufactured in Aruba for lifefactors. Arthrospira contains good quality of proteins, sulfated polysaccharides, γ-linoleic acid, along with an array of carotene and phytopigments, vitamins, and minerals which are reported to be antioxidant, immunomodulator, antihyperglycemic, antidyslipidemic, cardioprotective, hepatoprotective, antiviral, anticancerous, antihypertensive, anti-inflammatory, analgesic, neuroprotective and renoprotective activities. Several studies have shown arthrospira, and active ingredients of it revealed various pharmacological activities. It can be used for the management of various ailments such as diabetes, dyslipidemia, obesity, hypertension, cancer, arthritis, osteoarthritis, autoimmune disorders, etc. This review attempts to explore the hidden benefits of Oxy+ (arthrospira).

Oxy+ (arthrospira) and its medicinal importance: an appraisal

Oxy+ is a natural source of arthrospira found in nature, used as a dietary supplement and manufactured in Aruba for lifefactors. Arthrospira contains good quality of proteins, sulfated polysaccharides, γ-linoleic acid, along with an array of carotene and phytopigments, vitamins, and minerals which are reported to be antioxidant, immunomodulator, antihyperglycemic, antidyslipidemic, cardioprotective, hepatoprotective, antiviral, anticancerous, antihypertensive, anti-inflammatory, analgesic, neuroprotective and renoprotective activities. Several studies have shown arthrospira, and active ingredients of it revealed various pharmacological activities. It can be used for the management of various ailments such as diabetes, dyslipidemia, obesity, hypertension, cancer, arthritis, osteoarthritis, autoimmune disorders, etc. This review attempts to explore the hidden benefits of Oxy+ (arthrospira).

Quantifying the Effect of Supplementation with Algae and Its Extracts on Glycolipid Metabolism: A Meta-Analysis of Randomized Controlled Trials

AIMS

The effect of algae and its extract supplementation on glycolipid metabolism has not been finalized. Therefore, the purpose of the meta-analyses was to assess the effects of its supplementation on glycolipid metabolism concentration.

METHODS

We have systematically searched PubMed, Web of Science, the Cochrane Library and Embase to identify randomized controlled trials (RCTs) that investigated the impact of algae and its extracts supplementation on glycolipid metabolism. Effect size analysis was performed using weighted mean difference (WMD) and 95% CI between the methods of the experiment group and the control group. Subgroup analyses were performed to explore the possible influences of study characteristics. Publication bias and sensitivity analysis were also performed.

RESULTS

A total of 27 RCTs (31 trials) with 1221 participants were finally selected for the meta-analysis. The algae and its extract intervention significantly decreased glycosylated hemoglobin (HbA1c, WMD = -0.18%; 95% CI: -0.27 to -0.10; p < 0.001), high-density lipoprotein cholesterol (HDL-C, WMD = -0.22 mmol/L; 95% CI: -0.38 to -0.06; p = 0.008), and triglycerides (TC, WMD = -0.31 mmol/L; 95% CI: -0.37 to -0.25; p < 0.001) levels and increased insulin (WMD = 6.05 pmol/mL; 95% CI: 4.01 to 8.09; p < 0.001) levels. It did not significantly change the blood glucose, homeostasis model assessment-insulin resistance index (HOMA-IR), 2-h post-meal blood glucose (2hPBG) and other lipid profiles. Subgroup analyses based on the duration of intervention and subjects demonstrated that the intervention of algae and its extracts for 10 weeks or fewer and more than 40 subjects decreased TC levels (p < 0.05). Moreover, the intervention reduced TC and 2hPBG concentrations for East Asians (p < 0.05).

CONCLUSIONS

Our findings provided evidence that algae and its extract interventions were beneficial for the regulation of human glycolipid metabolism. More precise RCTs on subjects are recommended to further clarify the effect of algae, seaweed polysaccharide, seaweed polypeptide, algae polyphenol and its products intervention on glycolipid metabolism.

Transport of ACE Inhibitory Peptides Ile-Gln-Pro and Val-Glu-Pro Derived from Spirulina platensis Across Caco-2 Monolayers

This study evaluated transepithelial transport mechanisms of Ile-Gln-Pro (IQP) and Val-Glu-Pro (VEP), two ACE-inhibitory peptides derived from Spirulina platensis, using human intestinal Caco-2 cell monolayers. IQP and VEP were absorbed intact through Caco-2 cell monolayers with P_app values of 7.48 ± 0.58 × 10^-6 and 5.05 ± 0.74 × 10^-6 cm/s, respectively. The transport of IQP and VEP were affected neither by Gly-Pro nor by wortmannin, indicating that they were not PepT1-mediated and did not involve endocytosis. However, transport of IQP and VEP were increased significantly by sodium deoxycholate, suggesting that the major transport mechanism was paracellular. In addition, the increased transport of VEP and IQP were followed with the addition of sodium azide, suggesting influence of energy to the process. The transport of VEP was also increased by verapamil, indicating an apical-to-basolateral flux mediated by P-gp.

PRACTICAL APPLICATION

Bioactive peptides derived from food proteins have been considered as potentially ideal products to reduce hypertension because of their safety and positive impacts on health. IQP and VEP are the 2 ACE inhibitory peptides derived from Spirulina platensis, a kind of edible cyanobacteria with rich nutrition and multiple physiological functions, and were demonstrated to inhibit ACE and lower blood pressure in spontaneously hypertensive rats. However, it is prerequisite that such bioactive peptides must be absorbed intact across the intestinal epithelium, so as to exert antihypertensive effects in vivo. This study evaluated transepithelial transport mechanisms of IQP and VEP. It contributes to the study of Spirulina in lowering blood pressure and supports the development of bioactive peptide products.

Quantifying the effects of spirulina supplementation on plasma lipid and glucose concentrations, body weight, and blood pressure

PURPOSE

Spirulina is generally used as a nutraceutical food supplement due to its nutrient profile, lack of toxicity, and therapeutic effects. Clinical trials have investigated the influence of spirulina on metabolic-related risk factors but have yielded conflicting results in humans. Here, we summarize the evidence of the effects of spirulina on serum lipid profile, glucose management, BP, and body weight by conducting a meta-analysis.

MATERIALS AND METHODS

Relevant studies were retrieved by systematic search of MEDLINE, EMBASE, Scopus databases, and reference lists of relevant original studies from inception to July 2018. Data were extracted following a standardized protocol. Two investigators independently extracted study characteristics, outcomes measures, and appraised methodological quality. Effect sizes were performed using a random-effects model, with weighted mean differences (WMDs) and 95% CIs between the means for the spirulina intervention and control arms. Subgroup analyses were conducted to explore the possible influences of study characteristics. Publication bias and sensitivity analysis were also performed.

RESULTS

A total of 1,868 records were identified of which 12 trials with 14 arms were eligible. The amount of spirulina ranged from 1 to 19 g/d, and intervention durations ranged from 2 to 48 weeks. Overall, data synthesis showed that spirulina supplements significantly lowered total cholesterol (WMD = -36.60 mg/dL; 95% CI: -51.87 to -21.33; P=0.0001), low-density lipoprotein cholesterol (WMD = -33.16 mg/dL; 95% CI: -50.52 to -15.75; P=0.0002), triglycerides (WMD = -39.20 mg/dL; 95% CI: -52.71 to -25.69; P=0.0001), very-low-density lipoprotein cholesterol (WMD = -8.02 mg/dL; 95% CI: -8.77 to -7.26; P=0.0001), fasting blood glucose (WMD = -5.01 mg/dL; 95% CI: -9.78 to -0.24; P=0.04), and DBP (WMD = -7.17 mmHg; 95% CI: -8.57 to -5.78; P=0.001). These findings remained stable in the sensitivity analysis, and no obvious publication bias was detected.

CONCLUSION

Our findings provide substantial evidence that spirulina supplementation has favorable effect on select cardiovascular and metabolic biomarkers in humans, including lipid, glucose, and DBP management.

Supplementation with Phycocyanobilin, Citrulline, Taurine, and Supranutritional Doses of Folic Acid and Biotin-Potential for Preventing or Slowing the Progression of Diabetic Complications

Oxidative stress, the resulting uncoupling of endothelial nitric oxide synthase (eNOS), and loss of nitric oxide (NO) bioactivity, are key mediators of the vascular and microvascular complications of diabetes. Much of this oxidative stress arises from up-regulated nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity. Phycocyanobilin (PhyCB), the light-harvesting chromophore in edible cyanobacteria such as spirulina, is a biliverdin derivative that shares the ability of free bilirubin to inhibit certain isoforms of NADPH oxidase. Epidemiological studies reveal that diabetics with relatively elevated serum bilirubin are less likely to develop coronary disease or microvascular complications; this may reflect the ability of bilirubin to ward off these complications via inhibition of NADPH oxidase. Oral PhyCB may likewise have potential in this regard, and has been shown to protect diabetic mice from glomerulosclerosis. With respect to oxidant-mediated uncoupling of eNOS, high-dose folate can help to reverse this by modulating the oxidation status of the eNOS cofactor tetrahydrobiopterin (BH4). Oxidation of BH4 yields dihydrobiopterin (BH2), which competes with BH4 for binding to eNOS and promotes its uncoupling. The reduced intracellular metabolites of folate have versatile oxidant-scavenging activity that can prevent oxidation of BH4; concurrently, these metabolites promote induction of dihydrofolate reductase, which functions to reconvert BH2 to BH4, and hence alleviate the uncoupling of eNOS. The arginine metabolite asymmetric dimethylarginine (ADMA), typically elevated in diabetics, also uncouples eNOS by competitively inhibiting binding of arginine to eNOS; this effect is exacerbated by the increased expression of arginase that accompanies diabetes. These effects can be countered via supplementation with citrulline, which efficiently enhances tissue levels of arginine. With respect to the loss of NO bioactivity that contributes to diabetic complications, high dose biotin has the potential to "pinch hit" for diminished NO by direct activation of soluble guanylate cyclase (sGC). High-dose biotin also may aid glycemic control via modulatory effects on enzyme induction in hepatocytes and pancreatic beta cells. Taurine, which suppresses diabetic complications in rodents, has the potential to reverse the inactivating impact of oxidative stress on sGC by boosting synthesis of hydrogen sulfide. Hence, it is proposed that concurrent administration of PhyCB, citrulline, taurine, and supranutritional doses of folate and biotin may have considerable potential for prevention and control of diabetic complications. Such a regimen could also be complemented with antioxidants such as lipoic acid, N-acetylcysteine, and melatonin-that boost cellular expression of antioxidant enzymes and glutathione-as well as astaxanthin, zinc, and glycine. The development of appropriate functional foods might make it feasible for patients to use complex nutraceutical regimens of the sort suggested here.

The influence of obesity on the effects of spirulina supplementation in the human metabolic response of Korean elderly

BACKGROUND/OBJECTIVES

Spirulina, a blue-green alga, is widely produced and commercialized as a dietary supplement with bio- and immune-modulatory functions. We have previously shown that spirulina had favorable effects on lipid profiles, immune functions, and antioxidant capacity in healthy Korean elderly. Despite favorable effect of spirulina supplementation, some sub-populations have shown a poor response to supplementation. Obesity is a factor related to poor-response. Therefore, the purpose of this study was to determine the immuno-modulation, antioxidant capacity, and lipid-lowering effect of spirulina in obese and non-obese Korean elderly.

SUBJECTS/METHODS

The subjects were 78 elderly aged 60-87 years. In a randomized double blind, placebo-controlled study, subjects were fed either placebo or spirulina daily, at 8 g for 12 weeks. Subjects were divided into the non-obese group and the obese group based on body mass index (BMI) criteria for Asians suggested by the International Obesity Task Force: BMI < 25 kg/m² (non-obese) and BMI ≥ 25 kg/m² (obese).

RESULTS

In the non-obese group, spirulina supplementation showed a significant lowering effect on plasma concentration of total cholesterol and LDL-cholesterol, a significant increase in interleukin (IL)-2 concentration (P < 0.01) and a significant increment (P < 0.05) in IL-2/IL-6 ratio, and a significant increase in total antioxidant status level and a significant decrease in thiobarbituric acid reactive substances level. However, these effects were not observed in the obese group.

CONCLUSIONS

These results demonstrated that blood lipid lowering and immune and antioxidant improving response for spirulina supplement was affected by obesity in Korean elderly.