Macroalgae Extracts From Antarctica Have Antimicrobial and Anticancer Potential

Rosiane M Martins; Fernanda Nedel; Victoria B S Guimarães; Adriana F da Silva; Pio Colepicolo; Claudio M P de Pereira; Rafael G Lund

doi:10.3389/fmicb.2018.00412

Macroalgae Extracts From Antarctica Have Antimicrobial and Anticancer Potential

Front Microbiol. 2018 Mar 8:9:412. doi: 10.3389/fmicb.2018.00412. eCollection 2018.

Authors

Rosiane M Martins¹, Fernanda Nedel², Victoria B S Guimarães², Adriana F da Silva², Pio Colepicolo³, Claudio M P de Pereira⁴, Rafael G Lund²

Affiliations

¹ Post-Graduate Program in Biochemistry and Bioprospecting, Federal University of Pelotas, Pelotas, Brazil.
² Post-Graduate Program in Dentistry, School of Dentistry, Federal University of Pelotas, Pelotas, Brazil.
³ Department of Biochemistry, Institute of Chemistry, State University of São Paulo, São Paulo, Brazil.
⁴ Center of Chemical, Pharmaceutical and Food Sciences, Federal University of Pelotas, Pelotas, Brazil.

Abstract

Background: Macroalgae are sources of bioactive compounds due to the large number of secondary metabolites they synthesize. The Antarctica region is characterized by extreme weather conditions and abundant aggregations of macroalgae. However, current knowledge on their biodiversity and their potential for bio-prospecting is still fledging. This study evaluates the antimicrobial and cytotoxic activity of different extracts of four macroalgae (Cystosphaera jacquinotii, Iridaea cordata, Himantothallus grandifolius, and Pyropia endiviifolia) from the Antarctic region against cancer and non-cancer cell lines. Methods: The antimicrobial activity of macroalgae was evaluated by the broth microdilution method. Extracts were assessed against Staphylococcus aureus ATCC 19095, Enterococcus faecalis ATCC 4083, Escherichia coli ATCC29214, Pseudomonas aeruginosa ATCC 9027, Candida albicans ATCC 62342, and the clinical isolates from the human oral cavity, namely, C. albicans (3), C. parapsilosis, C. glabrata, C. lipolytica, and C. famata. Cytotoxicity against human epidermoid carcinoma (A-431) and mouse embryonic fibroblast (NIH/3T3) cell lines was evaluated with MTT colorimetric assay. Results: An ethyl acetate extract of H. grandifolius showed noticeable antifungal activity against all fungal strains tested, including fluconazole-resistant samples. Cytotoxicity investigation with a cancer cell line revealed that the ethyl acetate extract of I. cordata was highly cytotoxic against A-431 cancer cell line, increasing the inhibitory ratio to 91.1 and 95.6% after 24 and 48 h exposure, respectively, for a concentration of 500 μg mL^-1. Most of the algal extracts tested showed little or no cytotoxicity against fibroblasts. Conclusion: Data suggest that macroalgae extracts from Antarctica may represent a source of therapeutic agents. HIGHLIGHTS Different macroalgae samples from Antarctica were collected and the lyophilized biomass of each macroalgae was extracted sequentially with different solventsThe antimicrobial and anticancer potential of macroalgae extracts were evaluatedEthyl acetate extract of H. grandifolius showed noticeable antifungal activity against all the fungal strains tested, including fluconazole-resistant samplesEthyl acetate extract of I. cordata was highly cytotoxic against the A-431 cancer cell lineMost of the algal extracts tested showed little or no cytotoxicity against normal cell lines.

Keywords: antibacterial agents; antifungal agents; antineoplastic agents; marine natural products; seaweeds.