RESUMO
In this paper, the lipid classes, compositions of the neutral lipids, phospholipids and fatty acids, acetylcholinesterase inhibition and cytotoxic activity of two brown algae Lobophora tsengii D. Tien & Z. Sun and Lobophora australis Z. Sun, F. C. Gurgel & H. Kawai have been investigated. The polar lipid class had the highest content in total lipid (TL) (43.47% in L. tsengii and 48.95% in L. australis). Phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were the main components in the phospholipids of two studied brown algae with contents varied from 32.27% to 52.33%. Total lipids were rich in PUFA (42.54% of total fatty acids for L. australis and 32.98% for L. tsengii), with EPA (11.46%, 14.30%) and AA (8.0%, 11.96%). L. tsengii methanol extract inhibited acetylcholinesterase (AChE) in in vitro assay with an IC50 value of 25.45 µg/mL. Both Lobophora methanol extracts display cytotoxic effects against four human cancer cell lines (KB, MCF7, HepG2 and A549) with IC50 in the range of 21.11-83.61 µg/mL. Especially, L. australis extract showed a strong cytotoxicity against KB cell lines with IC50 value of 21.11±0.39 µg/mL.