Cultura de tecidos, avaliação do potencial genotóxico, antigenotóxico, antineoplásico e análise fitoquímica de Schwartzia brasiliensis Choisy (Marcgraviaceae)

Abstract

Schwartzia brasiliensis is a native species, with neotropical distribution, usually found in salt marsh environments. Some studies indicate its medicinal potential with analgesic, anti-inflammatory, antibacterial and trypanocidal activity and DNA protective. Currently, cancer is recognized as the disease responsible for more deaths worldwide, and it s treatment usually invasive and not always effective, which stimulates the search for new drugs, including those from plant origin. Considering the need for exploitation of plant resources in a sustainable manner, plant tissue culture techniques can be used as an alternative to continous production of medicinal interest substances. Thus, this study aimed to establish different in vitro systems of S. brasiliensis, aiming at the production metabolites of medicinal interest, as well as evaluation of the genotoxic, antigenotoxic, antineoplastic potential and determining the phytochemical profile of extracts and fractions of materials obtained in vivo and in vitro. Studies have been conducted on the production of callus and cell suspensions evaluate and the influence of different growth regulators, luminosity, types of explants and elicitors on these systems. In addition, was evaluated the genotoxic, antigenotoxic, antineoplastic potential and the phytochemical profile of the material obtained in vivo and in vitro. The addition of the growth regulators KIN and PIC favored the production of friable callus in the presence or absence of light from leaf and stem explants, while the use of BAP associated with NAA influenced the production of compact callus from leaf explants, under light. The use of methyl jasmonate as elicitor induced higher accumulation of biomass in callus of S. brasiliensis. Cell suspension cultures were established from friable callus obtained from stem explants, in the absence of light. The assessment of the genotoxic and antigenotoxic potentials were conducted through plasmid DNA agarose gel electrophoresis and showed that aqueous and methanolic extracts of leaves and stems, besides the methanol extracts of cell suspensions obtained in vitro were able to reduce breakage caused by SnCl2, and did not cause DNA damage. The evaluation of antineoplasic potential of extracts and fractions in K562 cell line revealed through the cell viability test by MTT assay, the ethyl acetate fraction is more cytotoxic (IC50 = 32,94±6,49 µg mL), results demonstrated by optical microscopy. It was evaluated by flow cytometry technique, the type of death, DNA fragmentation and cell cycle induced by the fractions from methanolic extract of leaves of S. brasiliensis cultivated in vivo. All fractions induced cell death, mainly by necrosis. Only the aqueous fraction caused further fragmentation of the DNA compared to the negative control. In parallel, ethyl acetate and hexane fractions induced an increase in the number of cells in the S phase of the cell cycle. Analyses by HPLC-UV-DAD indicate that antigenotoxic and antineoplastic potentials of S. brasiliensis grown in vivo and in vivo, could be due to flavonoids. These results are the first studies for the species