Variations among Antioxidant Profiles in Lipid and Phenolic Extracts of Microalgae from Different Growth Medium

Abstract

Up-scaling the production of value added products from microalgae requires reliable techniques. This study has been carried out in order to determine whether microalgae have an inherent tendency to contain similar proportions of antioxidant properties in its lipid and phenolic extracts under varying growth medium. Chlorella vulgaris and Acutodesmus obliquus (Scenedesmus obliquus) were cultivated in normal water, Bold's medium and sewage water followed by extraction of lipids and phenolics. The extracts were subjected to in vitro antioxidant assays performed in triplicates in which higher scavenging activity of DPPH and super oxide radical was observed in phenolic extracts. However, there was a significantly higher antioxidant potential found in lipid extracts suggests that next to the well studied phenolic compounds, microalgal lipids should also be considered when using microalgae as a source of natural antioxidants. Further, antioxidant profile of lipid and phenolic extracts from same species varied with growth medium.

Lipid Profile, Antioxidant and Antihypertensive Activity, and Computational Molecular Docking of Diatom Fatty Acids as ACE Inhibitors

“…This might be because Trolox is a single compound acting as radical scavengers, while FAs contained both active and inactive forms. However, our results agreed with previous studies on algal lipids obtained from Grateloupia turuturu , Schizochytrium sp., Nannochloropsis oceanica, Chlorella vulgaris, and Acutodesmus obliquus with IC50 for DPPH scavenging assays of 0.2 to 30 mg/mL [ 36 , 37 ], and ABTS IC50 values of 0.1 to 80 mg/mL [ 6 , 36 , 38 ]. Results indicated that the lipid extracts of Ano and Rho had reducing ability to stabilize unstable DPPH free radicals by converting them to a more stable form [ 15 ] and reducing the ABTS free radical through the oxidation reaction [ 6 ].…”