Biomedical properties of cystoseira species: insights into nutra- and pharmaceutical applications

Duarte, Catarina Vizetto Guerreiro

Publication

Biomedical properties of cystoseira species: insights into nutra- and pharmaceutical applications

2016-11-24Doctoral thesis

datacite.subject.fos	Ciências Naturais::Ciências Biológicas	pt_PT
dc.contributor.advisor	Varela, J.
dc.contributor.author	Duarte, Catarina Vizetto Guerreiro
dc.date.accessioned	2017-02-22T16:26:54Z
dc.date.available	2017-02-22T16:26:54Z
dc.date.issued	2016-11-24
dc.date.submitted	2016
dc.description	Tese de doutoramento, Ciências Biológicas, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2016
dc.description.abstract	Brown algae contain interesting nutritional profiles, usually with low levels of lipids but relatively high amounts of polyunsaturated fatty acids (PUFA) and minerals. Moreover, brown algae have secondary metabolites that display several biological activities. However, studies on the chemical composition, bioactive compounds and respective biological activities of brown algae are scarce. Here it is shown that Cystoseira species have potential biotechnological applications. Among the species evaluated, C. tamariscifolia and C. baccata were those that in general had the highest ash, protein and lipid contents, while the highest levels of moisture and total carbohydrates were detected in C. nodicaulis and C. compressa. Cystoseira species had also high amounts of K, Ca and Fe, and a favorable Na/K ratio. C. tamariscifolia, C. compressa and C. nodicaulis stood out for their high polyunsaturated/saturated fatty acids (PUFA/SFA) and low n-6/n- 3 PUFA ratios as well as appropriate unsaturation, atherogenicity and thrombogenicity indices, suggesting a high nutritional value. C. tamariscifolia hexane extract had the highest antioxidant and anti-proliferative activities against a panel of tumoral cells. This extract was particularly selective for hepatocarcinoma cells (HepG2) when compared to non-tumoral cells. HepG2 cells presented pro-apoptotic features and disaggregation on 3D multicellular tumor spheroids after incubation with the extract. Demethoxy cystoketal chromane was isolated and identified as an anti-proliferative compound, selective towards HepG2 cells. Furthermore, isololiolide was isolated for the first time also from C. tamariscifolia hexane extract. The latter compound exhibited significant cytotoxic activity against three human tumoral cell lines, namely HepG2 cells, whereas no cytotoxicity was found in non-malignant human fibroblasts. Isololiolide disrupted the HepG2 normal cell cycle and induced apoptosis. Moreover, it altered the expression of proteins that are important in the apoptotic cascade, increasing PARP cleavage and p53 protein expression, and decreasing procaspase-3 and Bcl-2 expression levels. Taken together, the results here presented highlight the potential of Cystoseira macroalgae as sources of products for nutra- and pharmaceutical applications.	pt_PT
dc.identifier.tid	101382880	pt_PT
dc.identifier.uri	http://hdl.handle.net/10400.1/9004
dc.language.iso	eng	pt_PT
dc.relation	Biomedical properties of Cystoseira species: insights into nutra- and pharmaceutical applications
dc.rights.uri	http://creativecommons.org/licenses/by/4.0/	pt_PT
dc.subject	Biological activities	pt_PT
dc.subject	Cystoseira	pt_PT
dc.subject	Natural compounds	pt_PT
dc.subject	Nutrition	pt_PT
dc.subject	PUFA	pt_PT
dc.title	Biomedical properties of cystoseira species: insights into nutra- and pharmaceutical applications	pt_PT
dc.type	doctoral thesis
dspace.entity.type	Publication
oaire.awardTitle	Biomedical properties of Cystoseira species: insights into nutra- and pharmaceutical applications
oaire.awardURI	info:eu-repo/grantAgreement/FCT//SFRH%2FBD%2F81425%2F2011/PT
project.funder.identifier	http://doi.org/10.13039/501100001871
project.funder.name	Fundação para a Ciência e a Tecnologia
rcaap.rights	openAccess	pt_PT
rcaap.type	doctoralThesis	pt_PT
relation.isProjectOfPublication	3b77bed2-f2d5-45e7-8d6b-cd98f5f5a60d
relation.isProjectOfPublication.latestForDiscovery	3b77bed2-f2d5-45e7-8d6b-cd98f5f5a60d
thesis.degree.grantor	Universidade do Algarve, Faculdade de Ciências e Tecnologia
thesis.degree.level	Doutor
thesis.degree.name	Ciências Biológicas	pt_PT