Bioactivity evaluation and composition of extracts from sub-Antarctic macroalgae Mazzaella laminarioides at distinct development phases

Sub-Antarctic macroalgae can be a feasible source of innumerous bioactive compounds that can display important biological activities. In this sense, the aims of this work were to evaluate the chemical composition, antimicrobial activity and cytotoxic potential of n-hexane extracts from sub-Antarctic seaweed Mazzaella laminarioides (Bory) Fredericq at distinct development phases. Results showed that extracts were constituted of as much as 65 distinct compounds that could be distributed mainly among hydrocarbons, fatty acids, sterols and fatty alcohols. Generally, there were significant differences (P < 0.05) in the concentrations of compounds comparing distinct development phases. Antimicrobial evaluation indicated that n-hexane extracts of cystocarpic and tetrasporophytic phase of M. laminarioides inhibited the growth of most organisms tested, reaching minimum inhibitory concentrations of 0.0312 mg mL−1 against Enterococcus faecalis (Andrewes and Horder) and 0.25 mg mL−1 against Acinetobacter baumannii (Bouvet and Grimont). Cytotoxic evaluation of extracts showed no toxicity to normal cells at concentrations below 1 mg mL−1. Therefore, M. laminarioides from the sub-Antarctic region had antimicrobial potential that could be explored on further commercial applications.