Algae from Portuguese Coast Presented High Cytotoxicity and Antiproliferative Effects on an In vitro Model of Human Colorectal Cancer

BACKGROUND: The marine environment has shown to be an interesting source of new antitumor agents, representing an important tool in cancer research. OBJECTIVE: The aim of this study was to evaluate the antitumor activities of 12 algae from Peniche coast (Portugal) on an in vitro model of human colorectal cancer (Caco-2 cells). MATERIALS AND METHODS: The antitumor potential was accessed by evaluating Caco-2 cell's viability and proliferation through the 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide and calcein-AM methods. RESULTS: The dichloromethane extracts of Asparagopsis armata and Sphaerococcus coronopifolius induced the highest decrease on cell's viability (1 mg/mL; 24 h), 98.96% ± 0.39% and 98.08% ± 0.89%, respectively, followed by the methanolic extracts of S. coronopifolius (96.47% ± 1.26%) and A. armata (92.68% ± 1.17%). Regarding cell proliferation, the highest decrease of Caco-2 cell's proliferation (1 mg/mL; 24 h) was induced by the dichloromethane extract of A. armata (100% ± 0.48%), S. coronopifolius (99.04 ± 0.51%), and Plocamium cartilagineum (95.05% ± 1.19%). The highest potency was shown by the dichloromethane extract of S. coronopifolius in both, cytotoxicity and antiproliferative tests, with an IC(50) of 21.3 and 36.5 μg/mL, respectively. CONCLUSION: The extracts of A. armata and S. coronopifolius are promising sources of new bioactive molecules with application in cancer therapeutics. SUMMARY: Algae from Peniche coast (Portugal) revealed to be a promising source of new bioactive compounds with potential application on cancer therapeutics. Abbreviations Used: MTT: 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide; DMSO: Dimethyl sulfoxide; FBS: Fetal bovine serum; MEM: Minimum Essential Medium; SEM: Standard error of the mean; SP : Sulfated polysaccharides [Image: see text]