BIBLIOS

Document type
Journal articles

Document subtype
Full paper

Title
Can macroalgae provide promising anti-tumoral compounds? A closer look atCystoseira tamariscifoliaas a source for antioxidant and anti-hepatocarcinoma compounds

Participants in the publication
Catarina Vizetto-Duarte (Author)
Luísa Custódio (Author)
Gerardo Acosta (Author)
João H.G. Lago (Author)
Thiago R. Morais (Author)
Carolina Bruno de Sousa (Author)
Katkam N. Gangadhar (Author)
Maria João Rodrigues (Author)
Hugo Pereira (Author)
Raquel T. Lima (Author)
M. Helena Vasconcelos (Author)
Luísa Barreira (Author)
Amélia P. Rauter (Author)
Dep. Química e Bioquímica
CQB
Fernando Albericio (Author)
João Varela (Author)

Summary
Marine organisms are a prolific source of drug leads in a variety of therapeutic areas. In the last few years, biomedical, pharmaceutical and nutraceutical industries have shown growing interest in novel compounds from marine organisms, including macroalgae. Cystoseira is a genus of Phaeophyceae (Fucales) macroalgae known to contain bioactive compounds. Organic extracts (hexane, diethyl ether, ethyl acetate and methanol extracts) from three Cystoseira species (C. humilis, C. tamariscifolia and C. usneoides) were evaluated for their total phenolic content, radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radicals, and antiproliferative activity against a human hepatocarcinoma cell line (HepG2 cells). C. tamariscifolia had the highest TPC and RSA. The hexane extract of C. tamariscifolia (CTH) had the highest cytotoxic activity (IC50 = 2.31 µg/mL), and was further tested in four human tumor (cervical adenocarcinoma HeLa; gastric adenocarcinoma AGS; colorectal adenocarcinoma HCT-15; neuroblastoma SH-SY5Y), and two non-tumor (murine bone marrow stroma S17 and human umbilical vein endothelial HUVEC) cell lines in order to determine its selectivity. CTH strongly reduced viability of all tumor cell lines, especially of HepG2 cells. Cytotoxicity was particularly selective for the latter cells with a selectivity index = 12.6 as compared to non-tumor cells. Incubation with CTH led to a 2-fold decrease of HepG2 cell proliferation as shown by the bromodeoxyuridine (BrdU) incorporation assay. CTH-treated HepG2 cells presented also pro-apoptotic features, such as increased Annexin V/propidium iodide (PI) binding and dose-dependent morphological alterations in DAPI-stained cells. Moreover, it had a noticeable disaggregating effect on 3D multicellular tumor spheroids. Demethoxy cystoketal chromane, a derivative of the meroditerpenoid cystoketal, was identified as the active compound in CTH and was shown to display selective in vitro cytotoxicity towards HepG2 cells.

Editor(s)
Jason Hoyt Peter Binfield


Institution
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA

Where published
PeerJ

Publication Identifiers
ISSN - 2167-8359

Publisher
PeerJ



Document Identifiers
DOI - https://doi.org/10.7717/peerj.1704
URL - http://dx.doi.org/10.7717/peerj.1704

Rankings
SCIMAGO Q1 (2016) - 1,124 - Medicine (miscellaneous)

Keywords
Anti-hepatocarcinoma Antioxidant Brownalgae Marine natural products Cystoseira

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