Phytoscreening of Vochysiaceae species: Molecular identification by HPLC-ESI-MS/MS and evaluating of their antioxidant activity and inhibitory potential against human α-amylase and protein glycation

Abstract

Scientific research based on medicinal plants has been highlighted as a complementary treatment to T2DM, stand out the Vochysiaceae family, which have been widely used in folk medicine by traditional South American communities to treat some diseases. Our study aimed to investigate the antioxidant and antiglycation activities of ethanol extracts of leaves (LF) and stem barks (SB) of Vochysiaceae species, evaluated their capacities to inhibit glycoside and lipid hydrolases related to T2DM and molecular identification by HPLC-ESI-MS/MS. Our main findings indicate that the ethanolic extract of four of eight analyzed plants such as LF and SB of Q. grandiflora, Q. parviflora, V. elliptica and Calisthene major exhibited, respectively, potential of α-amylase inhibition (IC₅₀ of LF: 5.7 ± 0.6, 4.1 ± 0.5, 5.8 ± 0.5, 3.2 ± 0.6 and IC₅₀ of SB: 3.3 ± 0.7, 6.2 ± 2.0, 121.0 ± 8.6 and 11.2 ± 2.8 μg/mL), capacities of antioxidant (ORAC of LF: 516.2 ± 0.1, 547.6 ± 4.9, 544.3 ± 6.1, 442.6 ± 2.4 and ORAC of SB: 593.6 ± 22.3, 497.7 ± 0.8, 578 ± 12.3, 593.6 ± 19.5 µmol trolox eq/g; FRAP of LF: 796.1 ± 0.9, 427.7 ± 22.0, 81.0 ± 1.9, 685 ± 37.9 and FRAP of SB: 947.4 ± 24.9, 738.6 ± 24.3, 98.8 ± 7.9, 970.8 ± 13.9 µmol trolox eq/g; DPPH IC₅₀ of LF: 14.2 ± 1.8, 36.3 ± 6.9, 11.8 ± 1.9, 13.3 ± 1.2 and DPPH IC₅₀ of SB: 16.0 ± 3.0, 15.5 ± 1.9, 126.1 ± 23. 6, 5.3 ± 0.3 μg/mL, respectively) and antiglycation (BSA/Frutose IC₅₀ of LF: 43.1 ± 3.4, 52.1 ± 6.0, 175.5 ± 32, 8, 111.8 ± 14.7 and BSA/Frutose IC₅₀ of SB:, 40.1 ± 11.9, 51.2 ± 16. 7, 46.6 ± 5.7, 53.5 ± 13.6 μg/mL) and presence of polyphenols, such as flavonoids and condensed tannins. The extracts presented low ability to inhibit α-glycosidase and lipase enzymes in the initial assays, with values below 40% of inhibition. In BSA/methylglyoxal, only Q. grandiflora SB, V. eliptica LF and V. tucanorum LF showed activity (IC₅₀: 655.5 ± 208.5, 401.9 ± 135.2 and 617.1 ± 80.6 μg/mL, respectively) and only C. major LF and SB, in Arg/methylglyoxal (IC₅₀: 485.1 ± 130.8 and 468.0 ± 150.5 μg/ml, respectively). This study presented new findings about the biological and pharmacological potential of some species of Vochysiaceae family, contributing to the understanding of the action and efficacy in use of these plants, in their management of postprandial hyperglycemia and in glycation and oxidative processes that contribute to managing diabetes mellitus.

Keywords: Advanced glycation end products; Plant antioxidants; Polyphenols; Postprandial hyperglycemia.