M. S. Miranda

Bio: M. S. Miranda is an academic researcher from Federal University of Bahia. The author has contributed to research in topics: TBARS & Thiobarbituric acid. The author has an hindex of 1, co-authored 1 publications receiving 324 citations.

Antioxidant activity of the microalga Spirulina maxima

Abstract: Spirulina maxima, which is used as a food additive, is a microalga rich in protein and other essential nutrients. Spirulina contains phenolic acids, tocopherols and beta-carotene which are known to exhibit antioxidant properties. The aim of the present study was to evaluate the antioxidant capacity of a Spirulina extract. The antioxidant activity of a methanolic extract of Spirulina was determined in vitro and in vivo. The in vitro antioxidant capacity was tested on a brain homogenate incubated with and without the extract at 37 degrees C. The IC50 (concentration which causes a 50% reduction of oxidation) of the extract in this system was 0.18 mg/ml. The in vivo antioxidant capacity was evaluated in plasma and liver of animals receiving a daily dose of 5 mg for 2 and 7 weeks. Plasma antioxidant capacity was measured in brain homogenate incubated for 1 h at 37 degrees C. The production of oxidized compounds in liver after 2 h of incubation at 37 degrees C was measured in terms of thiobarbituric acid reactant substances (TBARS) in control and experimental groups. Upon treatment, the antioxidant capacity of plasma was 71% for the experimental group and 54% for the control group. Data from liver spontaneous peroxidation studies were not significantly different between groups. The amounts of phenolic acids, alpha-tocopherol and beta-carotene were determined in Spirulina extracts. The results obtained indicate that Spirulina provides some antioxidant protection for both in vitro and in vivo systems.

Antioxidant potential of microalgae in relation to their phenolic and carotenoid content

Abstract: In the past decades, food scientists have been searching for natural alternatives to replace synthetic antioxidants. In order to evaluate the potential of microalgae as new source of safe antioxidants, 32 microalgal biomass samples were screened for their antioxidant capacity using three antioxidant assays, and both total phenolic content and carotenoid content were measured. Microalgae were extracted using a one-step extraction with ethanol/water, and alternatively, a three-step fractionation procedure using successively hexane, ethyl acetate, and water. Antioxidant activity of the extracts varied strongly between species and further depended on growth conditions and the solvent used for extraction. It was found that industrially cultivated samples of Tetraselmis suecica, Botryococcus braunii, Neochloris oleoabundans, Isochrysis sp., Chlorella vulgaris, and Phaeodactylum tricornutum possessed the highest antioxidant capacities in this study and thus could be a potential new source of natural antioxidants. The results from the different types of extracts clearly indicated that next to the well-studied carotenoids, phenolic compounds also contribute significantly to the antioxidant capacity of microalgae.

Biomass Nutrient Profiles of Three Microalgae: Spirulina platensis, Chlorella vulgaris, and Isochrisis galbana

Abstract: Nutritional composition was determined for Spirulina platensis, Chlorella vulgaris, and Isochrisis galbana cultures. Data include the proximate composition, energy value, mineral elements, and fatty acid composition. Sixteen strains of these microalgae were obtained as a percentage of total fat. Total PUFA, SFA contents, n-3/n-6 ratios, and eicosapentaenoic acid (EPA)/docosahexaenoic acid (DHA) ratios were obtained. Protein content was high in Spirulina samples, whereas Isochrisis had the highest ash content. Spirulina is a rich source of γ-linolenic acid (GLA); Chlorella was an important source of PUFAs. Spirulina is a rich source of K, Chlorella is rich in P, and Isochrisis is a good source of Ca and Mg. Se content of Isochrisis is higher than in the other microalgae.

Hypolipidemic, Antioxidant, and Antiinflammatory Activities of Microalgae Spirulina

Abstract: Spirulina is free-floating filamentous microalgae growing in alkaline water bodies. With its high nutritional value, Spirulina has been consumed as food for centuries in Central Africa. It is now widely used as nutraceutical food supplement worldwide. Recently, great attention and extensive studies have been devoted to evaluate its therapeutic benefits on an array of diseased conditions including hypercholesterolemia, hyperglycerolemia, cardiovascular diseases, inflammatory diseases, cancer, and viral infections. The cardiovascular benefits of Spirulina are primarily resulted from its hypolipidemic, antioxidant, and antiinflammatory activities. Data from preclinical studies with various animal models consistently demonstrate the hypolipidemic activity of Spirulina. Although differences in study design, sample size, and patient conditions resulting in minor inconsistency in response to Spirulina supplementation, the findings from human clinical trials are largely consistent with the hypolipidemic effects of Spirulina observed in the preclinical studies. However, most of the human clinical trials are suffered with limited sample size and some with poor experimental design. The antioxidant and/or antiinflammatory activities of Spirulina were demonstrated in a large number of preclinical studies. However, a limited number of clinical trials have been carried out so far to confirm such activities in human. Currently, our understanding on the underlying mechanisms for Spirulina's activities, especially the hypolipidemic effect, is limited. Spirulina is generally considered safe for human consumption supported by its long history of use as food source and its favorable safety profile in animal studies. However, rare cases of side-effects in human have been reported. Quality control in the growth and process of Spirulina to avoid contamination is mandatory to guarantee the safety of Spirulina products.

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

Abstract: 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.