Evaluation of antioxidant properties of some naturally isolated microalgae: Identification and characterization of the most efficient strain (original) (raw)

Evaluation of the Antioxidant Activity of Cell Extracts from Microalgae

Marine Drugs, 2013

A growing market for novel antioxidants obtained from non-expensive sources justifies educated screening of microalgae for their potential antioxidant features. Characterization of the antioxidant profile of 18 species of cyanobacteria (prokaryotic microalgae) and 23 species of (eukaryotic) microalgae is accordingly reported in this paper. The total antioxidant capacity, accounted for by both water-and lipid-soluble antioxidants, was evaluated by the (radical cation) ABTS method. For complementary characterization of cell extracts, a deoxyribose assay was carried out, as well as a bacteriophage P22/Salmonella-mediated approach. The microalga Scenedesmus obliquus strain M2-1 exhibited the highest (p > 0.05) total antioxidant capacity (149 ± 47 AAU) of intracellular extracts. Its scavenger activity correlated well with its protective effects against DNA

Evaluation of antioxidant capacity and total phenolic content of different fractions of selected microalgae

Food Chemistry, 2007

In order to identify new sources of safe and inexpensive antioxidants, the antioxidant capacity and total phenolic content of different fractions of 23 microalgae were evaluated, using Trolox equivalent antioxidant capacity assay and the Folin–Ciocalteu method, respectively. The microalgae were extracted using hexane, ethyl acetate and water by a three-step sequential extraction procedure. Most of these microalgae were evaluated for

Effect of extraction method and solvent system on the phenolic content and antioxidant activity of selected macro- and microalgae extracts

Journal of Applied Phycology, 2019

The interest in using marine organisms as a source of novel bioactive compounds has increased recently, reinforcing the need to find efficient and cost-effective methods to extract these biocompounds. Thus, the present study has focused on evaluating four solvent systems and three extraction methods to obtain extracts of three macroalgae (Gracilaria sp., Fucus vesiculosus, and Ulva rigida) and two microalgae (Chlorella sp. and Nannochloropsis gaditana). The extracts were evaluated regarding yield, phenolic content, and potential antioxidant activity. Results showed that a lower organic solvent:water ratio increased macroalgae, but not microalgae, biomass extraction efficiency. Levels of total phenolics, ortho-diphenols and flavonoids were highly influenced by algae material and solvent system applied. Strong 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) scavenging activity was obtained with ethanol:water, 80:20 (E80:20) microalgal extracts, while no visible trend was detected for macroalgae extracts. However, methanolic extracts were the most effective in scavenging of 2,2-diphenyl-1picrylhydrazyl (DPPH). In macroalgae, a high positive correlation was observed between phenolic content and antioxidant capacity while in microalgae, the opposite was verified, suggesting that in microalgae, phenolic compounds are not the main contributors to the observed antioxidant capacity.

Characterization of Novel Selected Microalgae for Antioxidant Activity and Polyphenols, Amino Acids, and Carbohydrates

Marine Drugs

The biochemical composition of three novel selected microalgae strains (Chlorophyta) was evaluated to confirm their potential possibilities as new sustainably produced biomass with nutritional, functional, and/or biomedical properties. Extracts from cultured Pseudopediastrum boryanum, Chloromonas cf. reticulata, and Chloroidium saccharophilum exhibited higher radical scavenging activity of DPPH (1,1-diphenyl-2-picrylhydrazyl) when compared to butylated hydroxytoluene (BHT), but lower than butylated hydroxyanisole (BHA). Total phenolic compounds and amino acids were determined by newly developed RP-HPLC methods. Total phenolic contents, as µg g−1 of dry biomass, reached 27.1 for C. cf. reticulata, 26.4 for P. boryanum, and 55.8 for C. saccharophilum. Percentages of total analysed amino acids were 24.3, 32.1, and 18.5% of dry biomass, respectively, presenting high values for essential amino acids reaching 54.1, 72.6, and 61.2%, respectively. Glutamic acid was the most abundant free am...

Total Phenolic Content, Biomass Composition, and Antioxidant Activity of Selected Marine Microalgal Species with Potential as Aquaculture Feed

Antioxidants

There has been growing interest in microalgal biomolecules for health and cosmetics, as well as in the use of microalgae as aquaculture feed due to the need to replace fishmeal and fish oil with sustainable yet equally nutritious alternatives. Aim of this study is to evaluate the potential of five marine microalgal species, namely Chlorella minutissima, Dunaliella salina, Isochrysis galbana, Nannochloropsis oculata and Tisochrysis lutea, for the co-production of antioxidants and aquaculture feed. Batch cultivation was performed under saturating light intensity and continuous aeration. Freeze-dried biomass was extracted sequentially with water and methanol and evaluated for phenolic content and antioxidant activity, as well as proximate composition and fatty acid profile. Methanolic extracts of C. minutissima presented the highest phenolic content, measured with the Folin–Ciocalteu assay, and antioxidant activity. However, HPLC and LC-MS showed the presence of non-pigment compounds o...

Phenolic Profile and Antioxidant Activity of Crude Extracts from Microalgae and Cyanobacteria Strains

Journal of Food Quality, 2017

Arthrospira platensis) were screened for their radical scavenging activity against the stable radical 1,1-diphenyl-2-picrylhydrazyl. Despite the fact that water was a more efficient solvent to extract greater amount of extractable substances, it seems that methanol was more efficient to extract a selected group of compounds with a higher antioxidant activity. In addition, the identification of 4 simple phenolics (gallic, syringic, protocatechuic, and chlorogenic acids) and the flavonoids (+) catechin and (−) epicatechin was carried out by using reverse phase high performance liquid chromatography. The strain Euglena cantabrica showed the highest concentration of phenolic compounds, particularly gallic and protocatechuic acids (5.87 and 2.97 mg per gram of dried biomass, resp.). Aqueous and methanolic extracts of microalgae Euglena cantabrica also exhibited the highest antioxidant activity, probably due to the presence of the high contents of phenolics.

Aqueous extracts of microalgae exhibit antioxidant and anticancer activities

Asian Pacific journal of tropical biomedicine, 2012

To investigate the antioxidant and anticancer activities of aqueous extracts of nine microalgal species. Variable percentages of major secondary metabolites (total phenolic content, terpenoids and alkaloids) as well as phycobiliprotein pigments (phycocyanin, allophycocyanin and phycoerythrin) in the aqueous algal extracts were recorded. Antioxidant activity of the algal extracts was performed using 2, 2 diphenyl-1-picrylhydrazyl (DPPH) test and 2,2'- azino-bis (ethylbenzthiazoline-6-sulfonic acid (ABTS.(+)) radical cation assay. Anticancer efficiency of the algal water extracts was investigated against Ehrlich Ascites Carcinoma cell (EACC) and Human hepatocellular cancer cell line (HepG2). Antioxidant activity of the algal extracts was performed using DPPH test and ABTS.(+) radical cation assays which revealed 30.1-72.4% and 32.0-75.9% respectively. Anticancer efficiency of the algal water extracts was investigated against Ehrlich Ascites Carcinoma Cell (EACC) and Human Hepatoce...

Screening of antioxidant and cytotoxic activities of several microalgal extracts with pharmaceutical potential

Health and Technology

The bioactive molecules from microalgae have important properties such as antioxidant, anticancer, antiviral, antibacterial, antihypertensive, skin regenerative, neuroprotective, sunscreen, and, immunostimulatory effects. Bioactive molecules derived from microalgae is getting intense attention from pharmaceuticals, cosmetics and nutraceuticals industries because of these properties and numerous researches have been done to investigate the role of these bioactive molecules that can enlighten microalgal biotechnology to result in new nature derived pharmaceutical formulations. In this study we investigate antioxidant activities of crude extracts of G. Galdieria sulphuraria, Ettlia carotinosa, Neochloris texensis, Chlorella minutissima, Stichococcus bacillaris, Schizochytrium limacinum, Crypthecodinium cohnii, and Chlorella vulgaris with determining radical scavenging activity (RSA) by DPPH (2,2-diphenyl-1-picrylhydrazyl hydrate radical) method and total phenolic content by Folin-Ciocalteu method. Selected extracts according to their antioxidant activities cytotoxicity was evaluated after exposure to human hepatocellular liver carcinoma cells (HepG2) for 48 h. Antioxidant activities of these species ranged from 89 to 95% RSA (radical scavenging activity) while their phenolic contents were also very high, varied from 41 to 312 mg GAE (gallic acid equivalents)/ mg extract. MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay also showed microalgae has a potential to be used as a novel therapeutic compound.