Estudo fitoquímico e atividades biológicas de duas espécies da família Asteraceae
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Data
2020-08-31
Autores
Feleti, Sula Maria Vieira
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Universidade Federal do Espírito Santo
Resumo
Galinsoga parviflora Cav. and Vernonia polyanthes (Spreng.) Less are medicinal plants belonging to the Asteraceae family that show several biological activities. This study aimed to perform the chemical characterization of G. parviflora and V. polyanthes extracts, produced with the aerial parts, and to evaluate their antioxidant and cytotoxic actions in human lymphocytes, sarcoma-180 and in human gastric adenocarcinoma cells, using in vitro assays. Initially, using the aerial part, a crude ethanolic extract of each investigated species was prepared and, afterwards, phytochemical prospecting was performed by colorimetric reactions, followed by the quantification of total content of phenols, flavonoids and tannins by spectrophotometry, and chemical characterization by mass spectrometry (ESI (-) FT-ICR MS and APCI (+) FT-ICR MS). Antioxidant activities were determined by the methods DPPH, ABTS, FRAP and Fe2+ chelating. Cytotoxicity and anti-cytotoxicity in human lymphocytes and cytotoxicity in sarcoma-180 and human gastric adenocarcinoma cells were evaluated by the MTT assay in vitro. Preliminary phytochemical exploration detected metabolites of the alkaloids, coumarins, steroids, saponins, flavonoids, tannins and triterpenes class in V. polyanthes, and in G. parviflora was observed alkaloids, steroids, flavonoids and tannins. The content of phenols, flavonoids and tannins were, respectively, 90.11 mg EAG g-1, 67.04 mg ER g-1 and 94.9 mg EAT g-1 for V. polyanthes, and 133.04 mg EAG g-1, 96.02 mg ER g-1 and 5.5 mg EAT g-1 for G. parviflora. The chemical characterization by mass spectrometry revealed for the extract of V. polyanthes, the presence of substances of the flavonoid (luteolin and luteolin-7-O-glucuronide), of phenolic acids (tipfeoylquinic acid and diglycosylated ferulic acid) and sesquiterpene lactones classes (piptocarpine A, glaucolide A). In the extract of G. parviflora, phenolic acids (caffeic acid, caffeoylquinic acid and tipfeoylquinic acid), steroids (stigmasterol and β-sitosterol) and fatty acids (linolenic acid, linoleic acid, palmitoleic acid and palmitic acid) were found. In the evaluation of antioxidant activity, the extract of the species V. polyanthes stood out in the Fe2+ ion chelating test with (EC50 = 32.45 μg. mL-1), and the extract of G. parviflora did not show good antioxidant results by the tested methods. Both species showed a tendency to promote cytotoxicity in human lymphocyte cells. Following the anti-cytotoxicity protocol, the two species stood out in the post-treatment condition, avoiding the damage caused by the cisplatin mutagen. Regarding the cytotoxic action in sarcoma-180 cells, there was only a significant reduction in cell viability when the cells were exposed to the extracts from both species for 48 hours. G. parviflora was the species with the greatest antiproliferative potential, which demonstrates a greater effectiveness of this extract. In relation to human gastric adenocarcinoma cells, the species V. polyanthes stood out, exerting a cytotoxic action similar to the cisplatin pattern. These findings reinforce the medicinal use of these plants, as well as suggest their potential use for the development of new drugs and for the treatment of cancers
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Antioxidante , Quelante de ferro , Lactonas sesquiterpênicas citotoxicidade , Adenocarcinoma gástrico , Sarcoma-180 , Antioxidant , Iron chelator , Sesquiterpene lactones , Cytotoxicity , Gastric adenocarcinoma