Antioxidant and anti-proliferative properties of extracts from heterotrophic cultures of Galdieria sulphuraria

Abstract

This study explores the possibility to use the extremophilic microalga Galdieria sulphuraria (strain 064) as a source of natural biomolecules with beneficial and protective effects on human health. Galdieria was cultivated in heterotrophy conditions and cells extracts for their antioxidant and anti-proliferative properties were tested. Galdieria extracts showed high antioxidant power tested through ABTS assay and revealed high glutathione and phycocyanin contents. Based on Annexin-V FITC/propidium iodide and MTT analysis, algae extracts inhibited the proliferation of human adenocarcinoma A549 cells (51.2% inhibition) through the induction of apoptosis without cell cycle arrest. Besides, cytotoxicity and cytometry assays showed a positive pro-apoptotic mechanism. On these bases, we suggest that G. sulphuraria from heterotrophic culture, for its therapeutic potential, could be considered a good candidate for further studies with the aim to isolate bioactive anti-cancer molecules.

Keywords:

• Galdieria sulphuraria
• antioxidant
• glutathione
• phycocyanin
• A549
• apoptosis

Acknowledgements

We thank Dr Alessandra Trocino and librarians of the National Cancer Institute, Naples, for providing excellent bibliographic services and assistance.