Extração de compostos hidrossolúveis do arilo carnoso (endocarpo) da Passiflora edulis f. flavicarpa e avaliação de sua atividade citotóxica/antitumoral

Abstract

Passion fruit originates in tropical America and has more than 150 species. Brazil is a biggest world producer of the Passiflora edulis f. flavicarpa, the yellow passion fruit. It has five parts: the albedo, flavedo, the fleshy aryl (endocarp), pulp and the seeds. The flashy aryl presents benefits to human health, due to its content in phenolic compounds, which are important for antioxidant activities, preventing oxidative damage and capable of preventing neurodegenerative diseases. Therefore, the objective of the present study was to extract water-soluble compounds from the autoclaved fleshy aryl of P. edulis f. flavicarpa and evaluate its cytotoxic/antitumor activity in hepatocellular carcinoma (HCC) cells, in the human HuH7.5 tumor lineage, in order to obtain greater knowledge about the cellular effects of this part of the passion fruit. The fleshy aril of passion fruit was autoclaved, because previous studies indicated higher amounts of phenolic compounds in the autoclaved flour of passion fruit albedo compared to untreated albedo flour. To evaluate the effect of the experimental extraction variables, the experimental design DCCR (central rotational composite design) 22 was used, with two independent variables (extraction time and temperature), the response variable being the concentration of phenolic compounds. The extraction tests were carried out in an ultrasonic bath, with a constant agitation of 100 rpm at the temperature and extraction time defined by the experimental design. The aqueous extracts were vacuum filtered through a synthetic woven filter (polyester) and placed in test tubes with an initial concentration of 0.025 g mL-1. The results obtained from the DCCR 22 showed that at a temperature of 90.0 °C and at the time of 27.0 min, the optimal point of the curve was defined. However, the values of 78.4 °C and 26.5 min were used for temperature and extraction time, respectively, as they presented the maximum extraction values for phenolic compounds, both variables being statistically significant.. The physical-chemical analysis of this extract showed that it has an acid character, with a pH value of 3.97 and 10.54% of total acidity, in addition to 3.5 ° Brix of soluble solids, which can be explained by the low state maturation period, and its moisture was 8.41%. The MTT cytotoxicity test with human hepatocellular carcinoma cells line HuH7.5, showed that all concentrations (except 300 μg mL-1), in the three evaluation times (24, 48 and 72 hours) showed higher mean absorbances and statistically different from the negative control, with an effect of cell proliferation. Thus, the data from the present study show that, despite the high extraction yield (39.60%) and the presence of antioxidants in the extract produced (49.20% DPPH inhibition in 30 minutes), other tumor strains must be evaluated, seeking to identify the biological activity of the aqueous extract of the autoclaved fleshy aril of the passion fruit produced.