Table 3.
Antioxidant activity evaluation of microalgae extracts by cellular assays (AA: ascorbic acid, Ac: acetone, CAA: cellular antioxidant activity, CHCl3: chloroform, CLPAA: cellular lipid peroxidation antioxidant activity, EtOH: ethanol, Hex: hexane, IC50: inhibition concentration 50, inhib.: inhibition, MeOH: methanol, NMR: nuclear magnetic resonance, PBS: phosphate buffer saline, ROS: reactive oxygen species, TPC: total phenolic compounds, US: ultrasounds).
| Microalgae Species | Antioxidant Assay | Composition Analyses | Antioxidant Activity | Positive Control | Molecules Involved in Antioxidant Activity | Extraction Method | Ref. |
|---|---|---|---|---|---|---|---|
| Chaetoceros calcitrans | Nitric oxide scavenging activity assay on RAW 264.7 cells (mouse macrophage) | metabolites profiling by 1H NMR + TPC | IC50: 3.5–187.7 µg mL−1 | IC50 quercetin = 4.7 µg mL−1
IC50 curcumin = 6.1 µg mL−1 |
Fucoxanthin (25), astaxanthin, violaxanthin, zeaxanthin, canthaxanthin (26), and lutein (27) | US (30 min, room t °C) + MeoH, 70% EtOH, Ac, CHCl3 or Hex | [88] |
| Botryococcus braunii | (i) ROS assay and (ii) Comet assay on NIH3T3 cells (mouse embryonic fibroblast cells) | - | extract at 0.1–0.05% (i) reduction of ROS production of 35% over the control (=no microalgae extract) after stress induction (ii) no activity |
(i) AA: reduction of ROS production by 64% over the control at 250 µM | - | crushing in PBS + silica sand | [90] |
| Pediastrum duplex, Halochlorococcum porphyrae, Oltmannsiellopsis unicellularis, Achnanthes longipes, Navicula sp., Amphora coffeaeformis | Comet assay on L5178 cells (mouse lymphoma cells) | Crude lipid content | extract at 25–100 µg mL−1 (i) inhibitory effect to DNA damage until 80% over the control (=no microalgae extract) after stress induction |
- | - | Enzymatic extraction by 5 carbohydrases and 5 proteases | [92] |
| Cylindrotheca closterium, Coscinodiscus actinocyclus, Nitzschia closterium, 2 Pseudo-nitzschia pseudodelicatissimastrains, Tetraselmis suecica, Isochrysis galbana, Skeletonema costatum, Lauderia annulata, Leptocylindrus danicus, Chaetoceros affinis, Odontella mobiliensis, Leptocylindrus aporus, Thalassiosira rotula, Thalassiosira weissflogii, 2 Skeletonema marinoistrains, Thalassiosira rotula, Skeletonema costatum, Stephanopyxis turris, Bacteriastrum hyalinum, Guinardia striata, Proboscia alata, Guillardia theta, Rhodomonas baltica, Rhinomonas reticulata, Alexandrium tamutum, Alexandrium andersonii, Ostreopsis ovata, Alexandrium minutum, Lepidodinium viride, Prorocentrum gracile | (i) CAA and (ii) CLPAA on HepG2 cells (human liver cancer cell line) | extract at 50 µg mL−1
(i) 66–70% inhib. for Ostreopsis ovata (ii) 61–74% inhib. for Ostreopsis ovata and 100% inhib. for Alexandrium minutum but both species showed toxicity in cytotoxicity assay |
- | - | US (1 min)+ H2O then addition of Ac + maceration (50 min, room temp.) then fractionation on Amberlite XAD16N resin | [91] |