Spirulina- An Edible Cyanobacterium with Potential Therapeutic Health Benefits and Toxicological Consequences.

Spirulina is a blue-green algae which is cultivated not only for its maximum protein content but also due to the presence of other essential nutrients such as carbohydrates and vitamins (A, C and E). It is also a storehouse of minerals including iron, calcium, chromium, copper, magnesium, manganese, phosphorus, potassium, sodium and zinc. Simultaneously, γ- linolenic acid (an essential fatty acid), as well as pigments such as chlorophyll A and phycobiliproteins (C-phycocyanin, allophycocyanin and β-carotene), is also a major component of its rich nutritional profile. Spirulina is known to have various promising effects on the prevention of cancer, oxidative stress, obesity, diabetes, cardiovascular diseases and anemia. Moreover, it also plays a positive role in treating muscular cramps. The safety recommended dosage of Spirulina is approximately 3-10 g/d for adults and it's biological value (BV) is 75 with a net protein utilization (NPU) of 62. Spirulina does not have pericardium due to which it does not hinder the absorption of iron by chelation with phytates or oxalates. On the contrasting note, it may have some adverse effects due to the toxins (microcystins, β-methylamino-L-alanine (BMAA)) produced by Spirulina which might contribute to acute poisoning, cancer, liver damage as well as gastrointestinal disturbances. Its long-term consumption may also lead to the pathogenesis of Alzheimer's disease and Parkinson's disease. The current review focuses on the various aspects of spirulina including its cultivation, nutritional composition, extraction techniques, health benefits, adverse effects, industrial scope and market value which could be beneficial for its utilization in the development of value-added products and supplementary foods due to its high content of protein and bioavailability of nutrients. • Spirulina is a nutrient-dense cyanobacterium which is composed of protein, carbohydrates, vitamins, minerals, essential fatty acids, antioxidants and pigments including chlorophyll A and Phycocyanin.• To avoid the contamination of Spirulina species by other algae, the specific pH maintenance of the media around 9-11 (alkaline) is mandatory.• Positive effects were noticed on the yield and productivity of Spirulina after its biomass was grown in polybags and greenhouse.• Its beneficial effects have been identified in particular reference to obesity, diabetes, hypertension, cardiovascular diseases, anemia, cancer, oxidative stress, arthritis, immunity as well as muscular cramps.• The toxins such as microcystins and hepatotoxins, produced by Spirulina, are accountable to cause acute poisoning, liver damage, gastrointestinal disturbances and cancer.• The safe recommended dosage of Spirulina for adults accounts to approximately 3-10 g/d, with 30 g/d being the maximum limit for consumption.