Identification of anti-lung cancer extract from Chlorella vulgaris C-C by antioxidant property using supercritical carbon dioxide extraction

In this study, supercritical carbon dioxide extraction (SC-CO₂) technology was developed to extract the active components (such as antioxidants) from a novel microalga, Chlorella vulgaris C-C, due to its superior advantages over conventional solvent or ultrasonic extraction methods. Using SC-CO₂ and ultrasonic extractions, the polyphenol contents of C. vulgaris C-C were 13.40 and 0.46 (mg_{gallic acid}/g lyophilized extract), respectively. The flavonoid content obtained from SC-CO₂ (3.18mg_quercetin/g lyophilized extract) was also significantly higher than from ultrasonic extraction (0.86mg_quercetin/g lyophilized extract). Investigation of C. vulgaris C-C extract from SC-CO₂ indicates strong antioxidant activities in radical scavenging, ferric reducing power and metal chelating abilities. In cell proliferation assay, the extract of C. vulgaris C-C inhibits human lung cancer H1299, A549, and H1437 cells in a dose-dependent manner. In addition, the treatment with extracts of C. vulgaris C-C effectively reduced the migration of tumor cells, suggesting the potential of using the C. vulgaris C-C extract to inhibit lung cancer metastasis.