| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 1.82 MB | Adobe PDF |
Authors
Advisor(s)
Abstract(s)
Ao longo dos últimos anos tem-se observado um interesse crescente pelo estudo de compostos naturais devido ao seu elevado potencial do ponto de vista medicinal. A seguir à celulose, a lenhina é o composto mais abundante na biosfera. É biosintetizada através do processo de lenhificação, iniciado pelos álcoois p-coumarílico, coniferílico e sinapílico, que originam unidades de fenilpropano (p-hidroxifenilo, guaiacilo e seringilo).
Neste trabalho, avaliou-se o potencial antioxidante e antitumoral de quatro lenhinas técnicas de origens diferentes (Indulin-AT, Curan-27-11P, Sarkanda e Alcell). As propriedades antioxidantes foram determinadas por ensaios in vitro (atividade captadora de radicais livres, poder redutor e inibição da peroxidação lipídica). O potencial citotóxico foi avaliado em linhas celulares tumorais humanas nomeadamente, MCF-7 (carcinoma de mama), NCI-H460 (carcinoma pulmão), HCT-15 (carcinoma de cólon), HeLa (carcinoma cervical) e HepG2 (carcinoma hepatocelular); e em culturas primárias de células de fígado de porco (PLP2) pelo método da sulforrodamina B (SRB).
Todas as amostras mostraram possuir propriedades bioativas, com maior destaque para a Alcell que demonstrou ter maior potencial antioxidante e antitumoral. Os resultados obtidos foram correlacionados com características estruturais e químicas das lenhinas estudadas. Com base nos dados obtidos pode concluir-se que as lenhinas ricas em unidades fenólicas de siringilo e pobres em p-hidroxifenilo demonstraram maior atividade antitumoral in vitro.
Over the past few years there has been a great interest in studying natural compounds due to their potentially high medicinal properties. Lignin is, after cellulose, the most abundant biopolymer on earth. It is obtained through the lignification process, initiated by p-coumaryl, coniferyl and sinapyl alcohols, which originate phenylpropane units (p-hydroxyphenyl, guaiacyl and syringyl). In the present work, the antioxidant and antitumor potential of four technical lignins from different origins (Indulin-AT, Curan-27-11P, Sarkanda and Alcell) were evaluated. Antioxidant properties were determined by in vitro assays (free radicals scavenging activity, reducing power and lipid peroxidation inhibition). The cytotoxic potential was evaluated, by sulforhodamine B assay, in different human tumor cell lines (MCF-7- breast carcinoma, NCI-H460- lung carcinoma, HCT-15- colon carcinoma, HeLa- cervical carcinoma and HepG2- hepatocellular carcinoma) and in non-tumor primary culture of porcine liver cells (PLP2). All the samples displayed bioactive properties, showing Alcell the highest antioxidant and antitumor potential. The obtained results were correlated with the chemical and structural features of the studied lignins. Based on the achieved results, it can be concluded that lignins rich in syringyl phenol units and poor in p-hydroxyphenyl ones gave higher in vitro antitumor activity.
Over the past few years there has been a great interest in studying natural compounds due to their potentially high medicinal properties. Lignin is, after cellulose, the most abundant biopolymer on earth. It is obtained through the lignification process, initiated by p-coumaryl, coniferyl and sinapyl alcohols, which originate phenylpropane units (p-hydroxyphenyl, guaiacyl and syringyl). In the present work, the antioxidant and antitumor potential of four technical lignins from different origins (Indulin-AT, Curan-27-11P, Sarkanda and Alcell) were evaluated. Antioxidant properties were determined by in vitro assays (free radicals scavenging activity, reducing power and lipid peroxidation inhibition). The cytotoxic potential was evaluated, by sulforhodamine B assay, in different human tumor cell lines (MCF-7- breast carcinoma, NCI-H460- lung carcinoma, HCT-15- colon carcinoma, HeLa- cervical carcinoma and HepG2- hepatocellular carcinoma) and in non-tumor primary culture of porcine liver cells (PLP2). All the samples displayed bioactive properties, showing Alcell the highest antioxidant and antitumor potential. The obtained results were correlated with the chemical and structural features of the studied lignins. Based on the achieved results, it can be concluded that lignins rich in syringyl phenol units and poor in p-hydroxyphenyl ones gave higher in vitro antitumor activity.
Description
Mestrado em cooperação com a Universidade de Salamanca