- (2013) Volume 5, Issue 4
BDS, Saveetha Dental College and Hospitals
Date of Submission: 19-07-2013 Date of Acceptance: 29-08-2013
Spirulina is a marine blue green algae which is being extensively studied as the biomass of these microalgae and the compounds they produce have been shown to possess several biological applications with numerous health benefits. Apart from being used as nutraceutical food supplement worldwide, it shows therapeutic benefits on an array of diseased conditions including hypercholesterolemia, hyperglycerolemia, cardiovascular diseases, inflammatory diseases, cancer and viral infections. Spirulina is also incorporated as a functional ingredient in food products and beverages. The people in Africa have been known for consuming as Arthrospira (formerly, Spirulina) as principle food for past 100 years. But it became famous after it was successfully used by NASA as a dietary supplement for astronauts on space missions. There have been numerous studies investigating the efficiency and current clinical applications of Spirulina in treating several diseases in the recent years.
Keywords
Spirulina,micro algae, Anti oxidant, Anti cancer,Anti Inflammatory, Hypo lipidemic activity.
Introduction
Spirulina is referred to Marine microalgae with spiral characteristics of its filaments. It is formally called Arthrospira, belonging to the class of cyanobacteria with characteristic photosynthetic capability. [1,2].
Spirulina naturally grows in high-salt alkaline water reservoirs in subtropical and tropical areas including America, Mexico, Asian and Central Africa [3,4]. There are many known species of Spirulina ,of those Spirulina platensis (Arthrospira platensis), Spirulina maxima (Arthrospira maxima) and Spirulina fusiformis (Arthrospira fusiformis) are the most intensively described species as having high degree of medicinal values.
Composition:
Spirulina contains the high (up to 70%) content of protein, and also vitamins, especially B12 and provitamin A (-carotenes), and minerals, especially iron. It is also rich in phenolic acids, tocopherols and -linolenic acid [5]. Spirulina lacks cellulose cell walls and therefore it can be easily digested [5].
Microalgae/cyanobacteria produce besides being one of the richest sources of proteins other value-added compounds, such as polyunsaturated fatty acids (PUFAs), carotenoids, phycobiliproteins, polysaccharides, vitamins, or sterol. Some of the produced PUFAs are essential 3-3 and 3-6 that can be included in functional, or nutraceutical foods,( eg.Spirulina)or as feed for chickens and cows, these, in turn, supplying eggs and milk enriched in those PUFAs. Other microalgae, or their derived-products, are used in the pharmaceutical industry, cosmetics, thalassotherapy, as biofertilizers, or as agents to fix soil particles, on golf-greens, as feed for animals, in aquaculture, or even in effluent treatments.
Arthrospira, is a promising cyanobacterium as it can be used in applications to lower hyperlipidaemia, hyperglycaemia, and hypertension, to protect against renal failure, and to promote growth of intestinal Lactobacillus [6 - 8].
Many toxicological studies have proven Spirulina's safety. Spirulina now belongs to the substances that are listed by the US Food and Drug Administration under the category Generally Recognized as Safe (GRAS) [9-13]
This review provides emphasis on presenting the up to date developments of the clinical application of Spirulina or its derivatives for various therapeutic processes and whether this has side effects on long term usage and further describes the methods of preventing contamination.
Clinical Trials & Therapeutic Applications:
? Spirulina and Chronic Fatigue:
Spirulina has been promoted as “the food of the future" with “exceptional constituents" that contribute to high energy levels. A few of these constituents such as polysaccharides (Rhamnose and Glycogen) and essential fat (GLA) are absorbed easily by human cells and help in energy release. Spirulina increases healthy lactobacillus in the intestine, enabling the production of Vitamin B6 that also helps in energy release. Despite this promotion, the only available placebo-controlled randomized trial showed that the scores of fatigue were not significantly different between spirulina and placebo. Spirulina administered at a dose of 3 g day−1 did not ameliorate fatigue more than the placebo in any of the four subjects and possibly it has no effect on chronic fatigue [14].
?Prevents Cell death:
Spirulina prevents cell death induced by free radicals. Aqueous extract of Spirulina has a protective effect against apoptotic cell death due to free radicals.[15]
? Anti Inflammatory Activity:
It has been well documented that Spirulina exhibits anti-inflammatory properties by inhibiting the release of histamine from mast cells [16,17]
In Human Subjects:
In addition to being a disorder of lipid metabolism, atherosclerosis is now recognized as a chronic inflammatory disease [18, 19]. Excessive inflammation within the arterial wall may increase the risk factor for cardiovascular diseases. Antiinflammatory activity present in spirulina may prove to be beneficial in combating cardiovascular diseases.
Influence of Spirulina on IgA levels in human saliva demonstrated that it enhances IgA production, suggesting a pivotal role of microalga in mucosal immunity. [20]
In a recent in vitro study, the antioxidant and antiinflammatory properties of four different Spirulina preparations were evaluated with a cellfree as well as a cell-based assay. It was found that Spirulina dose-dependently inactivated free superoxide radicals generated during an oxidative burst. Equally significant, Spirulina dosedependently reduced the metabolic activity of functional neutrophils, indicating the antiinflammatory activity[21].
Animal Studies:
A number of animal studies have been carried out to evaluate the antioxidant and/or antiinflammatory activities of Spirulina. In one study with aged male rats, Spirulina reversed agerelated increase in proinflammatory cytokines in cerebellum, such as tumor necrosis factor-alpha (TNFH) and TNFI. Spirulina supplementation also significantly decreased the oxidative marker MDA whereas increased the cerebellar betaadrenergic receptor function which was reduced by aging. The observation thus demonstrated the antioxidant and antiinflammatory activities of Spirulina in aged rats. [22]
?Hypo lipidemic Activity-combating Cholesterol:
Cardiovascular disease remains the number one cause of death in developed countries, despite increased awareness, and high cholesterol is one of the most important risk factors in atherosclerosis. Recent study administered Spirulina supplements in ischemic heart disease patients and found a significant reduction in blood cholesterol, triglycerides and LDL cholesterol and an increase in HDL cholesterol. More research is needed before Spirulina can be recommended to lower cholesterol levels but its role as a natural food supplement in combating hyperlipidaemia, in combination with other therapeutic options, should not be overlooked. [23]. A clinical study showed a significant reduction in LDL : HDL ratio in 15 diabetic patients who were given Spirulina. [24].
In the mouse study, supplementation of 16% Spirulina in a high fat and cholesterol diet resulted in a significant reduction in total serum cholesterol, LDL, VLDL cholesterol and phospholipids whereas serum HDL cholesterol was concurrently increased. In addition, high hepatic lipids induced by the high fat and cholesterol diet were markedly reduced by Spirulina consumption [25]. The mechanism behind the Hypolipedemic activity of spirulina is not yet brought to light.But there is a hypothesis suggesting Phycocyanin is a water soluble protein and enriched in Spirulina.
Ingestion of phycocyanin preparation made from SPC resulted in a significant decrease in serum total cholesterol and atherogenic index whereas serum HDL cholesterol was concurrently increased. It was thus suggested that phycocyanin might be the active ingredient in Spirulina responsible for the hypolipidemic activity [26].
? Anti Cancer Effect:
Cancer is one of the most threatening disease in the present day scenario.There are Anti cancer drugs in use but despite their great antitumoral activity in human, they produce unwanted sideeffects. It has been argued that the combined antioxidant and immune modulation characteristics of Spirulina may have a possible mechanism of tumor destruction and hence play a role in cancer prevention.
Recent study showed that when the Spirulina was enriched with Selinium and combined with the anticancer drugs, a significant decrease of the proliferation rate and an increase of apoptosis rate were observed. [27].
Thus Se-enriched Spirulina as a vector for anticancer drug delivery enables to associate any anticancer drug with Se (Patent FR1257009). This process allows high drug delivery and produce significant anti-proliferative effectThe functionalization of selenium nanoparticles (SeNPs) with Spirulina polysaccharides (SPS) has been developed in a study[28].Results suggest that the strategy to use SPS as a surface decorator could be an effective way to enhance the cellular uptake and anticancer efficacy of nanomaterials. SPS-SeNPs may be a potential candidate for further evaluation as a chemopreventive and chemotherapeutic agent against human cancers.
?Anti oxidant activity:
A study showed that supplementation of Spirulina with a daily dose of 8g for 4 weeks significantly prolonged the time to fatigue, reduced TBARS induced by excise, and increased the plasma glutathione, protein carbonyls, catalase, and total antioxidant capacity levels. [29]
C-phycocyanin (C-PC) is one of the major biliproteins of Spirulina with antioxidant and radical scavenging properties. C-PC, a selective cyclooxygenase-2 inhibitor, induces apoptosis in lipopolysaccharide-stimulated RAW 264.7 macrophages. It is also known to exhibit antiinflammatory and anticancer properties [30].
Phycocyanin has the ability to scavenge free radicals, including alkoxyl, hydroxyl and peroxyl radicals. It also decreases nitrite production, suppresses inducible nitric oxide synthase (iNOS) expression, and inhibits liver microsomal lipid peroxidation [31,32-42].
Consumption of spirulina:Safety or Harmful:
As even a coin has two sides there are both advantages and some disadvantages in consuming Spirulina as a food.There are reports from many studies which suggests the safety as well as harm in its long term usage.
Studies reporting safety of Spirulina:
Supplementation of Spirulina in the diet at the doses much higher than any anticipated human consumption did not cause any signs of embryotoxic effects.
Spirulina had no detectable adverse effects on reproductive performance, embryo and fetus development and growth [43].
Intake of diet containing Spirulina significantly increased litter size whereas birth weights of pups were comparable to those from other groups. Finally, a study with pregnant rats to assess the general reproductive performance showed that Spirulina feeding did not change body weight of male and female rats with no signs of toxicity and was not associated with any adverse effects on any measures of reproductive performance including fertility, gestation and abnormal pups [44].
Study reporting Spirulina as Harmful:
Finally, an association of Spirulina consumption and development of a mixed immunoblistering disorder with characteristic features of bullous pemphigoid and pemphigus foliaceus was reported in an 82-year-old healthy woman [44].
Despite of favorable safety profile in rodents, there were reports raising the concerns of the safety of Spirulina consumption. A low level of mercury and other heavy metals were reported in Spirulina grown in open water source [45]. Consumption of such Spirulina preparation could lead to increased deposit of mercury and other heavy metals causing toxic effects. However, with controlled water sources for growing Spirulina, commercial Spirulina products tested contained mercury or lead at the levels much lower than the guidelines for daily intake of those elements by the WHO’s Food and Agriculture Organization (FAO) [46]
Conclusion:
Spirulina is a micro algae which has an amazing potential to play a major role in Therapeutics. A little of its usage in medicine has been established by numerous studies still more of its hidden properties are yet to be explored. Some of its properties such as Anti oxidant, Anti inflammatory ,Anti cancer,Anti aging(prevents cell death),Drug delivery System .,etc. Along with there actions in Humans has been described briefly in this Review. Hope this review will serve the purpose of aiding in future Research work to unleash the futher components present in Spirulina. Spirulina has a promising role to be played in the upcoming developments of Modern Medicine.
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