Antioxidant and anti-cancer activities of brown and red seaweed extracts from Chilean coasts

This study evaluates the content of polyphenols, flavonoids and anthraquinones from sequential
extracts from four algae species from along the Chilean coastline: Desmarestia ligulata, Dictyota kunthii,
Laurencia chilensis and Chondracanthus chamissoi. The antioxidant capacity of these extracts was evaluated
through three complementary assays: the TRAP, FRAP, and DPPH assays. Additionally, the cytotoxic activity
of these extracts was determined through sulforhodamine B assays on two cancer cell lines, one colon (HT-29)
and one breast (MCF-7), and one non-tumor control group of epithelial colon cells (CoN). The greatest
antioxidant activity was detected in the ethyl acetate and dichloromethane extracts from L. chilensis in its TRAP
potential, ethyl acetate of D. kunthii in its FRAP potential, and finally D. ligulata in its DPPH radical scavenging
activity. The activities of this D. ligulata and L. chilensis extracts were significantly correlated with their
flavonoid contents. In addition, the dichloromethane extracts from D. kunthii and C. chamissoi showed strong
cytotoxic activity against HT-29 and MCF-7; however, the activity was not selective. Future research is
necessary to purify the bioactive compounds of interest and improve their selectivity for eventual therapeutic