Evalutation of the antitumour potential of microlgae extracts across colorectal cancer cell lines with different genetic profiles
Year: 2025
Type: dissertation
Abstract: Marine microalgae represent a promising and sustainable source of bioactive compounds with well-documented antioxidant, anti-inflammatory and anticancer properties. Aqueous and hydroethanolic extracts (100% water, 50:50 and 80:20 ethanol–water) of four microalgae species, Phaeodactylum tricornutum, Chlorella vulgaris, Tetraselmis chuii, and Arthrospira platensis, were obtained by ultrasound-assisted extraction and screened for their biochemical composition, antioxidant potential, and anticancer activity against colorectal cancer cell lines with different genetic backgrounds. These included HCT116 p53 wild-type (TP53 wild-type/KRAS-mutant), HCT116 p53-null (TP53 knockout/KRAS-mutant), HT-29 (BRAF-mutant/TP53 mutant), RKO (BRAF-mutant/TP53 wild-type), and the non-tumorigenic colon cell line CCD-841-CON. Aqueous and hydroethanolic solvents revealed marked differences in yield and biochemical composition. Aqueous extractions maximized yield and recovered hydrophilic macromolecules (proteins, polysaccharides, ashes, while hydroethanolic mixtures, especially 80:20, enriched lipophilic and amphiphilic metabolites (carotenoids, chlorophylls, lipids, and conjugated phenols). Arthrospira spp. showed the highest yield, protein, phenolic content, and antioxidant activity, whereas C. vulgaris and P. tricornutum were limited by rigid cell walls. Among the 12 extracts analyzed, P. tricornutum and C. vulgaris (80:20) exhibited the strongest inhibitory activity CRC cell lines, especially the ones with KRAS mutation. The IC₅₀ values for P. tricornutum were 157.7 μg/mL (HCT116p53 wild type) and 354.5 μg/mL (p53 null), while C. vulgaris showed IC₅₀ values of 131.2 μg/mL and 413.6 μg/mL under the same conditions, with low toxicity toward non-tumorigenic CCD-841-CON cells. Cell cycle analysis revealed a p53-dependent mechanism: P. tricornutum induced G1/S arrest, and C. vulgaris induced G2/M arrest in HCT116 p53 wild type cells. These effects were absent in p53-null cells, confirming the functional relevance of p53. When combined with 5-fluorouracil (5-FU), both extracts moderately enhanced antiproliferative responses, especially in p53-competent cells, suggesting complementary modulation through p53-dependent and redox-regulated pathways.
Author: Silva, Joana Pereira da
Language: Portuguese
Subfield: Aquatic Science
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W7169735915