Physalis pubescens L: avaliação físico química, bioativa, antioxidante, antimicrobiana e antitumoral de frutos oriundos da região Sul do Rio Grande do Sul

Abstract

Considered an unconventional food plant (UFP), Physalis pubescens L has exotic fruits with a distinctive flavor and shape. Physalis is a species that has not been explored and studied is characterized by bioactive compounds that confer functional and biological properties. Thus, the objective of this study was to characterize fruits of Physalis pubescens L from the spontaneous production in the southern region of Rio Grande do Sul, as well as to evaluate the bioactive, antioxidant, antibacterial and antitumor potential of the fruit. For this, samples were collected in the interior of Cerrito municipality in the southern region of Rio Grande do Sul - Brazil, from spontaneous planting and harvested at the maturation point and evaluated for pH, acidity, soluble solids, moisture, ashes, crude protein , crude fiber, lipids, carbohydrates and total caloric value. It was also determined the content of phenolic compounds, flavonoids, phenolic and carotenoid acids, as well as antioxidant assays by the methods of DPPH•, ABTS• and FRAP, antibacterial tests by diffusion disc and minimum inhibitory concentration (MIC) and antitumor assays through the MTT test on the B16F10, GL261, C6 and primary astrocyte (non-tumor cell) cultures in vitro. From the results it was possible to observe that the fruit is acidic, with a pH of 3,76, high acidity (4,8%), and a considerable lipid content of 1,96% (w.b). The highest bioactive compounds contents were found in the pulp, obtaining an average value of 142,83 mg EAG.100g-1 (d.b) for phenolic compounds; 136,21 μg EQ. g-1 (d.b) for flavonoids and 171,36 μg β-carotene.g-1 (d.b) for carotenoids. The FRAP method presented the highest result for the antioxidant activity in the pulp (738,16 μM ferrous sulphate.g-1 d.b) and the DPPH in the fruit seed (280,77 μM trolox.g-1 d.b). In the test of antibacterial potential only the disc diffusion method presented halos of inhibition against bacteria (Staphylococcus aureus and Listeria monocytogenes), and halos were not verified for E.coli. As for the antitumor assays, the results for the C6 glioma, B16F16 and GL 261 melanoma lines were dependent on the extract, the concentration used and the analysis time, and both extracts (pulp and seed) reduced cell viability in the range from 10,33% to 43,12%. It was possible to conclude that the fruits of Physalis pubescens presented important nutritional values, besides the hydralcoolic extracts of the pulp and the seed presented significant effects in the bioactive, antioxidant and antitumor profile.