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Abstract(s)
Os produtos naturais, principalmente compostos derivados de algas, apresentam atividades biológicas relevantes, podem ser auxiliares na prevenção de várias doenças, como diabetes, cancro e doenças cardiovasculares (CVDs) e explorados sobre o seu potencial de aplicação para tratamen-tos. Neste trabalho estudaram-se extratos aquosos das algas Eisenia bicyclis (Aramé), Porphyra te-nera (Nori) e Fucus vesiculosus (Fucus), na prevenção da hipercolesterolemia, principal fator de risco associado às CVDs. Para tal, avaliou-se o conteúdo em fenóis pelo método Folin-Ciocalteu, polissa-cáridos pelo método fenol-ácido sulfúrico, proteínas utilizando o 2-D Quant Kit, atividade antioxidante pelo método 2,2-difenil-1-picrilhidrazil (DPPH), inibição das enzimas acetilcolinesterase (AChE) e 3--hidroxi-3-metilglutaril-Coenzima A redutase (HMGR), segurança in vitro com linhas celulares huma-nas do fígado e intestino e redução da permeação do colesterol utilizando um modelo celular que simula a barreira gastrointestinal. Nenhum dos extratos demonstrou ter citotoxicidade nas linhas ce-lulares testadas. Dos extratos analisados, a Aramé demonstrou ter os melhores resultados em fenóis (0,1521 ± 0,0035 mg equivalentes floroglucinol/mL extrato), atividade antioxidante (65 ± 3 %), inibição da HMGR (79 ± 7 %) e redução da permeação do colesterol (32 ± 2 %). Por conseguinte, a Aramé foi encapsulada em nanopartículas (NPs) de albumina de soro bovino (BSA) para melhorar as suas propriedades e facilitar a sua administração e absorção. As NPs Aramé apresentaram um tamanho inferior a 300 nm, índice de polidispersão abaixo de 0,6 e carga superficial negativa. Da análise por microscopia eletrónica de varrimento inferiu-se que as NPs vazias e NPs Aramé apresentaram forma esférica. As NPs Aramé promoveram o aumento da redução da permeação de colesterol (51 ± 3 %) e maior inibição da AChE (66 ± 7 %) e HMGR (87 ± 4 %) relativamente ao extrato livre. No ensaio in vivo com ratos Wistar em que se administrou durante 4 semanas Aramé, Aramé com ezetimiba e NPs Aramé obteve-se um menor valor de colesterol para a Aramé (64 ± 2 % mg/dL), Aramé com ezetimiba (68 ± 2 % mg/dL) e NPs Aramé (72 ± 2 % mg/dL) relativamente ao controlo e a adminis-tração destes demonstrou ser segura, visto não se verificarem alterações histológicas a nível dos órgãos dos ratos. A administração de Aramé, NPs Aramé e Aramé com ezetimiba revelou alterações metabólicas no soro dos ratos relativamente aos ratos controlo, nomeadamente em metabolitos as-sociados à diminuição do colesterol total e LDL-C e aumento do HDL-C, revelando o efeito da Aramé e NPs Aramé sobre a redução do colesterol. Concluiu-se assim que a alga Aramé demonstrou capa-cidade de redução do risco de CVDs, sendo este efeito mais evidente após encapsulação em NPs de BSA.
Abstract Natural products, mainly algae-derived compounds, exhibit relevant biological activities, can be considered an effective alternative in the prevention of various diseases such as diabetes, cancer, and cardiovascular diseases (CVDs), and are explore for their potential application in treatments. In this work, we studied Eisenia bicyclis (Arame), Porphyra tenera (Nori) and Fucus vesiculosus (Fucus) algae extracts to prevent hypercholesterolemia, the main risk factor associated with CVDs. To this aim, the extracts were evaluated for phenolic content by the Folin-Ciocalteu method, polysaccharides by the phenol-sulfuric acid method, proteins using the 2-D Quant Kit, antioxidant activity by the reduc-tion of radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) method, inhibition of enzymes, such as acetyl-cholinesterase (AChE), and 3-hydroxy-3-methylglutaryl-Coenzyme A reductase (HMGR), in vitro safety using human liver and intestinal cells, and cholesterol reduction permeation using a cell line model that simulates the intestinal lining barrier. None of the extracts were shown to have cytotoxicity in the cell lines tested. Of the analyzed extracts, Arame was shown to have the best results in phenol content (0,1521 ± 0,0035 mg phloroglucinol equivalents/mL extract), antioxidant activity (65 ± 3 %), HMGR inhibition (79 ± 7 %), and cholesterol permeation reduction (32 ± 2 %). Therefore, Arame was selected for encapsulation into bovine serum albumin (BSA) nanoparticles (NPs) to improve its prop-erties and to facilitate administration and absorption. The Arame NPs showed a size below 300 nm, polydispersity index inferior to 0,6 and a negative surface charge. Through scanning electron micros-copy analysis, it was inferred that empty NPs and Arame NPs showed a spherical shape. Arame NPs promoted an increased reduction of cholesterol permeation (51 ± 3 %) and a higher inhibition of AChE (66 ± 7 %) and HMGR (87 ± 4 %) when compared to the free extract. In the in vivo assay with Wistar rats Arame, Arame with ezetimibe, and Arame NPs were administered for 4 weeks, a lower choles-terol value was obtained for Arame (64 ± 2 % mg/dL), Arame with ezetimibe (68 ± 2 % mg/dL) and Arame NPs (72 ± 2 % mg/dL), compared with the control, and the administration of these proved to be safe, since there were no histological changes at the organs of the rats. The administration of Arame, Arame NPs, and Arame with ezetimibe, revealed metabolic changes in the serum of the rats relatively to the control rats, namely in metabolites associated with a decrease in total cholesterol and LDL-C, and increase in HDL-C, which evidenced the effect of Arame and Arame NPs on cholesterol lowering. It was therefore concluded that the Arame alga, demonstrated the capacity to reduce the risk of CVDs, with this effect being more evident after BSA NPs encapsulation.
Abstract Natural products, mainly algae-derived compounds, exhibit relevant biological activities, can be considered an effective alternative in the prevention of various diseases such as diabetes, cancer, and cardiovascular diseases (CVDs), and are explore for their potential application in treatments. In this work, we studied Eisenia bicyclis (Arame), Porphyra tenera (Nori) and Fucus vesiculosus (Fucus) algae extracts to prevent hypercholesterolemia, the main risk factor associated with CVDs. To this aim, the extracts were evaluated for phenolic content by the Folin-Ciocalteu method, polysaccharides by the phenol-sulfuric acid method, proteins using the 2-D Quant Kit, antioxidant activity by the reduc-tion of radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) method, inhibition of enzymes, such as acetyl-cholinesterase (AChE), and 3-hydroxy-3-methylglutaryl-Coenzyme A reductase (HMGR), in vitro safety using human liver and intestinal cells, and cholesterol reduction permeation using a cell line model that simulates the intestinal lining barrier. None of the extracts were shown to have cytotoxicity in the cell lines tested. Of the analyzed extracts, Arame was shown to have the best results in phenol content (0,1521 ± 0,0035 mg phloroglucinol equivalents/mL extract), antioxidant activity (65 ± 3 %), HMGR inhibition (79 ± 7 %), and cholesterol permeation reduction (32 ± 2 %). Therefore, Arame was selected for encapsulation into bovine serum albumin (BSA) nanoparticles (NPs) to improve its prop-erties and to facilitate administration and absorption. The Arame NPs showed a size below 300 nm, polydispersity index inferior to 0,6 and a negative surface charge. Through scanning electron micros-copy analysis, it was inferred that empty NPs and Arame NPs showed a spherical shape. Arame NPs promoted an increased reduction of cholesterol permeation (51 ± 3 %) and a higher inhibition of AChE (66 ± 7 %) and HMGR (87 ± 4 %) when compared to the free extract. In the in vivo assay with Wistar rats Arame, Arame with ezetimibe, and Arame NPs were administered for 4 weeks, a lower choles-terol value was obtained for Arame (64 ± 2 % mg/dL), Arame with ezetimibe (68 ± 2 % mg/dL) and Arame NPs (72 ± 2 % mg/dL), compared with the control, and the administration of these proved to be safe, since there were no histological changes at the organs of the rats. The administration of Arame, Arame NPs, and Arame with ezetimibe, revealed metabolic changes in the serum of the rats relatively to the control rats, namely in metabolites associated with a decrease in total cholesterol and LDL-C, and increase in HDL-C, which evidenced the effect of Arame and Arame NPs on cholesterol lowering. It was therefore concluded that the Arame alga, demonstrated the capacity to reduce the risk of CVDs, with this effect being more evident after BSA NPs encapsulation.
Description
Keywords
Eisenia bicyclis (Aramé) Porphyra tenera (Nori) Fucus vesiculosus (Fucus) NPs de BSA Encapsulação de extrato Colesterol CVDs BSA NPs Extract encapsulation Cholesterol