Chemical composition, antioxidant, and cytotoxic potential of Nannochloropsis species extracts

Abstract

Context: Screening of natural biomolecules from microalgae. Background: The microalgae were recognized for their biological and pharmacological importance of active natural products with high antioxidant and antiproliferative profile. In the preliminary screening, three species Nannochloropsis sp. (NC) (green algae), Amphora sp. (diatom), and Nostoc sp. (blue-green algae) were tested and Nannochloropsis was selected based on their scavenging properties. Objective: The objective of the study is to explore the biological information of microalgal species where the clinical investigation is still quite limited. Materials and Methods: The phytochemical screening of selected NC. primarily comprises saponins, terpenoids, flavonoids, and phenols which were confirmed by high-performance thin-layer chromatography, Fourier transform infrared, and gas chromatography–mass spectra analysis. Results: The ethyl acetate extract Nannochloropsis hexane (EAENH) fraction showed 40.61 mg GAE/g, 68.77 mg QE/g, 5.73 mg/g, and 57.38 mg CHL/g for total phenolic, flavonoid, carotenoid, and sterol content, respectively. Moreover, antioxidant activities were evaluated for the extract showing high flavonoid and phenolic contents after partial purification with hexane. The half inhibitory concentration (IC50) values for EAENH was found to be 13.9, 21.22, and 14.58 μg/mL for 1,1-diphenyl-2-picrylhydrazyl radical, hydrogen peroxide, and reducing power assays, respectively. The antiproliferative activity of EAENH on human non-small lung cancer cell line (A549) IC50 value was 175 μg/mL using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Conclusion: The present study confirmed that the bioactive components present in the EAENH were accountable for excellent antioxidant and cytotoxic properties.