Aphanizomenon flos-aquae (dietary supplement)

Aphanizomenon flos-aquae (/əˌfænɪˈzɒmɪnɒn ˌflɒsˈeɪkwi/) is a species of cyanobacteria (blue-green algae) which is commercially processed into a dietary supplement. Aphanizomenon flos-aquae (AFA) is known to contain nutrients including essential fatty acids, active enzymes, vitamins, amino acids, minerals, proteins, complex carbohydrates, and phytochemicals and is marketed as a nutritional supplement.

Biology

Like other cyanobacteria and plants, AFA uses photosynthesis to produce the food material (glycogen) that is stored and utilized by the cell. While plants' cell walls are mainly cellulose, AFA's cell walls are composed of peptidoglycan (carbohydrates and peptides), the typical cell wall material of bacteria. Therefore, the designation "cyanobacteria" (Latin, cyano = blue-green) refers to the blue-green coloration of this bacterial subdivision, including AFA.

The cellular structure of AFA is that of a simple prokaryote. Most cyanobacteria are highly efficient photosynthesizers, even more so than plants. Algae utilize light energy from the sun, carbon dioxide from the air, and water to synthesize proteins, carbohydrates, and lipids. AFA is also able to directly use molecular nitrogen from the air to produce proteins and other nitrogen-containing biomolecules. This ability is widespread in prokaryotes, but unknown in eukaryotes.

Potential toxicity

Aphanizomenon flos-aquae as a species has both toxic and non-toxic forms.[1][2] While benefits have been indicated, toxicity has been shown in some strains of the species Aphanizomenon flos-aquae,[3] with cylindrospermopsin[4] and saxitoxins present,[5] and microcystins found contaminating AFA dietary supplements.[6] The World Health Organization's Guidelines For Drinking Water Quality note Anatoxin-a, saxitoxins, and cylindrospermopsins are present in the Aphanizomenon genus.[7] This linked article is about a single strain of AFA labeled as toxic that has been reclassified.[8] Colony-forming morphology is one of the characteristics of the species Aphanizomenon flos-aquae; conversely Aphanizomenon are not known to form colonies. Algologists Li and Carmichael noted colony formation, or lack thereof, and other morphologic distinctions when comparing Aphanizomenon flos-aquae with Aphanizomenon. Their genetic comparison of Aphanizomenon flos-aquae to other species in the genus Aphanizomenon indicates dissimilarity between Aphanizomenon flos-aquae and Aphanizomenon species.[8][9]

History

Cyanobacteria have been a staple in the diets of many cultures[10][11] and have been used for both food and commerce by indigenous peoples all over the globe, from Africa and Asia to the Americas, from the Chinese to the Aztecs and Mayans.[12]

Aphanizomenon flos-aquae began to be harvested as a human dietary supplement in the early 1980s. In 1998 a dry weight of approximately 2.2 million lbs (1 million kls.) of AFA was harvested for the subsequent production of supplements by a number of commercial harvesters.[12] Commercial standards vary greatly in terms of documenting product composition to the consumer.

Today, AFA is marketed as a nutrient-dense food, harvested primarily from Upper Klamath Lake in North America.[11]

Harvesting and processing

Cyanobacteria as a crop are sensitive to heat, light, and rapid spoilage. Some native cultures in Africa and the Americas used simple sun-drying methods for preservation, but it is likely that a significant amount of the nutritional value was lost in the process because of exposure to extreme heat during harvesting and processing.[10] The methods for harvesting and processing used to make cyanobacteria available for consumption today are critical factors in the quality and safety of the finished product.

AFA is processed by screening to remove debris, testing for contaminating species, storing at the optimum temperature, and drying by a method that preserves nutrients. As with any crop, differences exist with regard to harvesting procedures, quality control against contaminating species, adherence to proper processing to protect nutrients from degradation, and attention to adequate storage conditions of the processed algae.[11]

Nutritional value

Cyanobacteria are often marketed as a source of nutrients such as vitamins, minerals, essential fatty acids (including omega 3 fatty acids), beta-carotene, chlorophyll, phycocyanin, active enzymes, amino acids, proteins, complex sugars, phytonutrients, and other bioactive components.[13]

The nutrient content of Aphanizomenon flos-aquae is subject to much variation due to diverse habitats, environmental factors, and harvesting procedures, all of which influence the nutritional value; for example, altitude, temperature, and sun exposure can greatly affect lipid and pigment composition. As more is learned about the components of different cyanobacterial species, growers and harvesters are better able to determine the optimal growth conditions for obtaining optimal yields.

Vitamins

Aphanizomenon flos-aquae has been shown to contain varying amounts at least 13 vitamins: vitamin A (beta-carotene), vitamin C (ascorbic acid), vitamin E, vitamin K, and many of the B-complex vitamins including B1 (thiamin), B2 (riboflavin), B6 (pyridoxine), choline, biotin, niacin, folic acid, pantothenic acid, and B12 (cobalamin).[13] However, Aphanizomenon flos-aquae contains pseudovitamin B12 which can block absorption of true B12 and is therefore not suitable for use as a B12 source for humans.[14]

Minerals

Aphanizomenon flos-aquae contains minerals and trace minerals (including calcium, chloride, chromium, copper, iron, magnesium, manganese, phosphorus, sodium, and zinc). Whether or not AFA microalgae contain a balance of bioavailable minerals and trace minerals depends on the mineral content of their growth environment.

Protein

AFA is approximately 60% protein by dry weight.[13]

Essential fatty acids

Approximately 45% of the lipids (fats) of AFA are essential fatty acids. Aphanizomenon flos-aquae contains a balance of both linoleic acid (LA, an omega-6 fatty acid) and alpha-linolenic acid (ALA, an omega-3 fatty acid).

Photosynthetic pigments

Chlorophyll is the green pigment found in plants that is responsible for the production of oxygen through the process of photosynthesis. Chlorophyll is a significant phytonutrient[15] as well as a powerful antioxidant. AFA contains 1 to 2% chlorophyll (dry weight). AFA is also a source of phycocyanin (PC), a photosynthetic pigment with antioxidant and anti-inflammatory properties that contributes the 'blue' to blue-green algae.[13]

Phenylethylamine

AFA contains phenylethylamine (PEA).[16]

Evidence of health effects

A team at the Royal Victoria Hospital, Montreal, Canada, demonstrated that consumption of AFA results in an immediate change in the trafficking of immune cells. The effect is transient and cell-type specific. An extensive body of data documents that long-term consumption does not lead to hyper-stimulation of the immune system. According to researchers, AFA blue-green algae make natural killer cells "patrol" better throughout the body. These effects were seen when using a low oral dose of algae (1.5 gram), corresponding to a low amount of food supplementation.[17]

The special molecule that provides the blue color in blue-green algae is called phycocyanin. Depending on the algae source, the amount of phycocyanin can amount to up to 15% of the dry weight of the algae. Phycocyanin has antioxidant and anti-inflammatory effects.[18] One study evaluated the ability of a novel natural extract of AFA enriched with phycocyanin to protect normal human erythrocytes and blood plasma samples against oxidative damage in vitro. In red blood cells, oxidative hemolysis and lipid peroxidation induced by the aqueous peroxyl radical generator [2, 2'-Azobis (2-amidinopropane) dihydrochloride, AAPH] were significantly lowered by the AFA extract in a time- and dose-dependent manner; at the same time, the depletion of cytosolic glutathione was delayed. In plasma samples, the natural extract inhibited the extent of lipid oxidation induced by the pro-oxidant agent cupric chloride (CuCl2); a concomitant increase of plasma resistance to oxidation was observed as evaluated by conjugated diene formation.[19]

In recent years, there has been an increase of interest in microalgal metabolites. A water-based extract of Aphanizomenon flos-aquae containing high concentrations of phycocyanin inhibited the in vitro growth of one out of four tumor cell lines, indicating that at least some tumor cell types may be directly sensitive to killing by phycocyanin. Blue-green algae in general contain a significant amount of carotenoids, namely beta-carotene, lycopene, and lutein, providing microalgae with antioxidant properties. By their quenching action on reactive oxygen species, antioxidants carry intrinsic anti-inflammatory properties.[20]

Other research describes the identification of three new high molecular weight polysaccharide preparations isolated from food-grade microalgae that are effective activators of human monocytes/macrophages, including "Immunon" from Aphanizomenon flos-aquae. Immunostimulatory activity was measured using transcription factor-based bioassay. Each polysaccharide studied in this research, including AFA, substantially increased mRNA levels of interleukin and tumor necrosis factor-a (TNF-a). These polysaccharides are between one hundred and one thousand times more active for in vitro monocyte activation than polysaccharide preparations that are currently used clinically for cancer immunotherapy.[21]

Research also characterizes the effect of a water-soluble preparation from known agents that modulate the immune system. One such study suggests that the macrophage-activating properties of an AFA water-soluble preparation are mediated through pathways that are similar to LPS-dependent activation.[22]

The antimutagenic properties of whole, fresh-water AFA were tested using the Ames test. Simultaneous addition of both algae and Nitrovin (a mutagen) to the test medium did not reduce the mutagenic activity. Addition of freeze-dried AFA to the test medium 2–24 hours before the application of the mutagen reduced mutagenic activity.[23]

An ethanol extract of AFA-cellular concentrate has been shown to increase stem cell proliferative action when incubated with human adult bone marrow cells or human CD34+ hematopoietic progenitors in culture. The preliminary study suggests that the ethanol extract of AFA cellular concentrate may act to promote proliferation of human stem cell populations.[24]

Organic certification

Organic certification can be a lengthy and complicated process, and it is achieved only through strict compliance with established official regulations. Requirements vary from country to country, and generally involve a stringent set of production standards for growing, storage, processing, packaging, and shipping. It is up to individual algae producers to apply for and secure organic certification by adherence to the certifying agency's standards.

See also

References
  1. Carmichael, Wayne W.; Stukenberg, Mary; Betz, Joseph M. (2010). "Blue Green Algae (Cyanobacteria)". Encyclopedia of Dietary Supplements (2nd ed.). London, UK: Informa Healthcare. pp. 75–81. ISBN 978-1-4398-1928-9.
  2. Debella, HJ (2007). "Mass culture of Aphanizomenon flos-aquae Ralfs ex born. And Flah. Var. flos-aquae (cyanobacteria) from Klamath Falls, Oregon, USA, in closed chamber bioreactors". Ethiopian Journal of Biological Sciences. 4 (2). doi:10.4314/ejbs.v4i2.39019.
  3. Carmichael, Wayne W. (1994). "The Toxins of Cyanobacteria". Scientific American. 270 (1): 78–86. Bibcode:1994SciAm.270a..78C. doi:10.1038/scientificamerican0194-78. PMID 8284661.
  4. Preußel, Karina; Stüken, Anke; Wiedner, Claudia; Chorus, Ingrid; Fastner, Jutta (2006). "First report on cylindrospermopsin producing Aphanizomenon flos-aquae (Cyanobacteria) isolated from two German lakes". Toxicon. 47 (2): 156–62. doi:10.1016/j.toxicon.2005.10.013. PMID 16356522.
  5. Chen, Y; Liu, J; Yang, W (2003). "Effect of Aphanizomenon flos-aquae toxins on some blood physiological parameters in mice". Wei Sheng Yan Jiu. 32 (3): 195–7. PMID 12914277.
  6. Saker, M.L.; Jungblut, A.-D.; Neilan, B.A.; Rawn, D.F.K.; Vasconcelos, V.M. (2005). "Detection of microcystin synthetase genes in health food supplements containing the freshwater cyanobacterium Aphanizomenon flos-aquae". Toxicon. 46 (5): 555–62. doi:10.1016/j.toxicon.2005.06.021. PMID 16098554.
  7. World Health Organization (2011). Guidelines for Drinking-water Quality (PDF) (4th ed.). p. 293. ISBN 978-92-4-154815-1. Retrieved December 2, 2011. Table 11.1 Cyanotoxins produced by cyanobacteria. Aphanizomenon spp: Anatoxin-a, saxitoxins, cylindrospermopsins.
  8. Li, Renhui; Carmichael, Wayne W.; Pereira, Paulo (2003). "Morphological and 16S rRNA gene fividence for reclassification of the paralytic shellfish toxin producing Aphanizomenon flos-aquae LMECYA31 as Aphanizomenon issatschenkoi (Ctanophyceae)". Journal of Phycology. 39 (4): 814–8. doi:10.1046/j.1529-8817.2003.02199.x. INIST:15056815.
  9. Li, Renhui; Carmichael, Wayne W.; Liu, Yongding; Watanabe, Makoto M. (2000). "Taxonomic re-evaluation of Aphanizomenon flos-aquae NH-5 based on morphology and 16S rRNA gene sequences". Hydrobiologia. 438: 99–105. doi:10.1023/A:1004166029866. S2CID 28669008.
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  12. Barsanti, Laura; Gualtieri, Paolo (2006). Algae: anatomy, biochemistry, and biotechnology. Florida, USA: CRC Press. ISBN 978-0-8493-1467-4. Retrieved January 3, 2012.
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  14. Miyamoto, Emi; Tanioka, Yuri; Nakao, Tomoyuki; Barla, Florin; Inui, Hiroshi; Fujita, Tomoyuki; Watanabe, Fumio; Nakano, Yoshihisa (December 2006). "Purification and Characterization of a Corrinoid-Compound in an Edible CyanobacteriumAphanizomenon flos-aquaeas a Nutritional Supplementary Food". Journal of Agricultural and Food Chemistry. 54 (25): 9604–9607. doi:10.1021/jf062300r. ISSN 0021-8561. PMID 17147452.
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  19. Benedetti, Serena; Benvenuti, Francesca; Pagliarani, Silvia; Francogli, Sonia; Scoglio, Stefano; Canestrari, Franco (2004). "Antioxidant properties of a novel phycocyanin extract from the blue-green alga Aphanizomenon flos-aquae". Life Sciences. 75 (19): 2353–62. doi:10.1016/j.lfs.2004.06.004. PMID 15350832.
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  21. Pugh, Nirmal; Ross, Samir; Elsohly, Hala; Elsohly, Mahmoud; Pasco, David (2001). "Isolation of Three High Molecular Weight Polysaccharide Preparations with Potent Immunostimulatory Activity fromSpirulina platensis,Aphanizomenon flos-aquaeandChlorella pyrenoidosa". Planta Medica. 67 (8): 737–42. doi:10.1055/s-2001-18358. PMID 11731916. S2CID 32844645.
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