Mirtilo, gênero Vaccinium, cv. Misty cultivado no Brasil : caracterização química e atividade citotóxica em células de mamíferos

Abstract

The blueberry is originally from southern United States which is, characterized by a temperate climate. It was subsequently introduced in Brazil in, 1980. Currently, Vacaria (RS) is the city with the largest fruit production in Brazil, this is mainly because of its geographic region of very cold weather in the mountains, in Campos de Cima da Serra. Blueberries are known to be rich in anthocyanins, a substance found in the skin of the fruit and is associated with significant antioxidant activity with cardiovascular risk reduction, anti-inflammatory activity and antitumor. Hydroalcoholic extracts of whole fruit and skin and pulp fractions of the fruit and the methanol extract of the whole fruit of fruits blueberry of the cultivar Misty were chemically characterized by gas chromatography-mass spectrometry (GC-MS) and high-resolution electrospray ionization mass spectrometry (ESI-HRMS) in negative mode. The chemical identification confirmed the presence of anthocyanins in samples of whole fruit and skin of methanolic and hydroalcoholic extracts, delphinidin, cyanidin, petunidin, malvidin being found, and polyphenolic compounds such as chlorogenic acid, quercetins, proanthocyanidins in the pulp of the hydroalcoholic extract and the whole fruit of the hydroalcoholic and the methanol extract. All the extracts analyzed showed lower cytotoxicity in non-tumor cell line (MRC-5) and selectivity to tumor cell lines (Hep-2, HeLa, HT-29), with less activity in the extract from the pulp in relation to the other samples analyzed. An important decrease in cell viability in tumor cell lines was observed when increasing time of exposure (from 24h to 72h) using methanol extract of the whole fruit. Induction of apoptosis was observed after 24h and 72h exposure to ethanol and methanol extract by ethidium bromide and acridine orange staining, where the majority of tumor lines showed increase in percentage at late apoptosis stages and necrosis. The results here observed suggests that the extract of blueberry, Misty cultivar, presents biological activity in tumor cell lines, but further studies are needed to understand the mechanisms involved in cytotoxicity and evaluate the effectiveness of these species as possible antitumor agent are necessary.