Antioxidant compounds of Kielmeyera coriacea Mart. with α-amylase, lipase and advanced glycation end-product inhibitory activities.

Chronic hyperglycemia and hyperlipidemia are associated with excessive formation of reactive oxygen species and advanced glycation end-products. The present study aimed to evaluate the potential in vitro antidiabetic properties of Kielmeyera coriacea inner bark. The main phytochemical compounds were identified by UHPLC-ESI/MSn and the ethanol extract and its fractions were used to evaluate their antioxidant and anti-glycation capacities, as well as their inhibitory potential against glycoside and lipid hydrolases activities. The polar fractions, especially the n-butanol fraction, had free radical scavenging and quenching properties (ORAC and FRAP values>1800 and 1000 µmol trolox eq/g, respectively, and DPPH IC50<4 µg/mL), and inhibited ROS production (p < 0.01), lipid peroxidation (p < 0.001), glycation (IC50 ~ 10 µg/mL in the BSA-fructose assay; IC50 ~ 200 µg/mL in the BSA-methylglyoxal and arginine-methylglyoxal assays), α-amylase (IC50<0.1 µg/mL) and lipase (IC50<5 µg/mL), with no cytotoxicity. Biomolecules well-known as potent antioxidants were identified for the first time in the inner bark of K. coriacea, such as protocatechuic acid, epicatechin and procyanidins A, B and C. Together, our results support the antioxidant, anti-glycation and glycoside and lipid hydrolases inhibitory properties of the inner bark of K. coriacea, a species found in the Brazilian savanna, which makes it especially useful to combat oxidative stress and hyperglycemia and hyperlipidemia.

Justino AB ，Santana EC ，Franco RR ，Queiroz JS ，Silva HCG ，de Lima JP Júnior ，Saraiva AL ，Martins MM ，Lemos de Morais SA ，de Oliveira A ，Filho LRG ，Aquino FJT ，Espindola FS ... -  《-》

Annona muricata Linn. leaf as a source of antioxidant compounds with in vitro antidiabetic and inhibitory potential against α-amylase, α-glucosidase, lipase, non-enzymatic glycation and lipid peroxidation.

Annona muricata leaves are used in traditional medicine to manage diabetes mellitus and its complications. The aim of this study was to evaluate the potential in vitro antidiabetic properties of Annona muricata leaf by identifying its main phytochemical constituents and characterizing the phenolic-enriched fractions for their in vitro antioxidant capacity and inhibitory activities against glycoside and lipid hydrolases, advanced glycation end-product formation and lipid peroxidation. Ethanol extract of A. muricata leaf was subjected to a liquid-liquid partitioning and its fractions were used in enzymatic assays to evaluate their inhibitory potential against α-amylase, α-glucosidase and lipase, as well as their antioxidant (DPPH, ORAC, FRAP and Fe2+-ascorbate-induced lipid peroxidation assays) and anti-glycation (BSA-fructose, BSA-methylglyoxal and arginine-methylglyoxal models) capacities. In addition, identification of the main bioactive compounds of A. muricata leaf by HPLC-ESI-MS/MS analysis was carried out. Ethyl acetate (EtOAc) and n-butanol (BuOH) fractions showed, respectively, antioxidant properties (ORAC 3964 ± 53 and 2707 ± 519 μmol trolox eq g-1, FRAP 705 ± 35 and 289 ± 18 μmol trolox eq g-1, and DPPH IC50 4.3 ± 0.7 and 9.3 ± 0.8 μg mL-1) and capacity to reduce liver lipid peroxidation (p < .01). Also, EtOAc and BuOH, respectively, inhibited glycation in BSA-fructose (IC50 45.7 ± 13.5 and 61.9 ± 18.2 μg mL-1), BSA-methylglyoxal (IC50 166.1 ± 21.6 and 413.2 ± 49.5 μg mL-1) and arginine-methylglyoxal (IC50 437.9 ± 89.0 and 1191.0 ± 199.0 μg mL-1) assays, α-amylase (IC50 9.2 ± 2.3 and 6.1 ± 1.6 μg mL-1), α-glucosidase (IC50 413.1 ± 121.1 and 817.4 ± 87.9 μg mL-1) and lipase (IC50 74.2 ± 30.1 and 120.3 ± 50.5 μg.mL-1), and presented lower cytotoxicity, when compared to the other fractions and crude extract. Various biomolecules known as potent antioxidants were identified in these fractions, such as chlorogenic and caffeic acids, procyanidins B2 and C1, (epi)catechin, quercetin, quercetin-hexosides and kaempferol. This study presents new biological activities not yet described for A. muricata, which contributes to the understanding of the potential effectiveness in the use of the A. muricata leaf, especially its polyphenols-enriched fractions, for the management of diabetes mellitus and its complications.

Justino AB ，Miranda NC ，Franco RR ，Martins MM ，Silva NMD ，Espindola FS ... -  《-》

Antidiabetic effects of Syzygium cumini leaves: A non-hemolytic plant with potential against process of oxidation, glycation, inflammation and digestive enzymes catalysis.

Plant materials are commonly used in traditional medicine in order to treat various diseases such as Diabetes mellitus. Some plants, such as Syzygium cumini, have the capability to act controlling oxidative stress and protein glycation besides their potential to decrease hyperglycemia and hyperlipidemia by the inhibition of the catalysis of digestive enzymes. The aim of this study was to evaluate the antioxidant and antiglicant activity of S. cumini leaves fractions, their capacity to inhibit hydrolases and lipase enzymes, as well as the cytotoxicity effects against erythrocytes and comparate these results with isolate quercetin flavonoid. Ethnobotanical researches, carried out by academic studies at the Federal University of Uberlandia, led us to choose S. cumini as a potential plant for treatment of Diabetes mellitus. Fractions from ethanolic extract of S. cumini (hexane/Hex, dichloromethane/DCM, ethyl acetate/EtOAc, n-butanol/ButOH and water/H2O) were used to evaluate their antioxidant (DPPH, ORAC and FRAP) and antiglycant (BSA/fructose, BSA/methylglyoxal and Arginine/Methylglyoxal) activity as well as the inhibitory potential against α-amylase, α-glucosidase and lipase. In addition, identification of the main bioactive compounds of S. cuimini leaves by HPLC-ESIMS/MS analysis was carried out. Our results indicate that all fractions, for exception Hex, present noteworthy antioxidant activity, mainly in EtOAc and ButOH fractions (FRAP 1154.49 ± 67.37 and 1178.27 ± 21.26 μmol trolox eq g-1, respectively; ORAC 1224.63 ± 58.16 and 1313.53 ± 85.23 μmol trolox eq g-1, respectively; DPPH IC50 15.7 ± 2.4 and 23.5 ± 2.7 μg mL-1, respectively). Regarding the antiglycant activity (BSA/fructose and Arginine/Methylglyoxal models), all fraction, for exception Hex, presented inhibition higher than 85%. All fractions were capable to inhibit 100% of α-amylase and the fractions DCM, EtOAc and ButOH inhibited α-glucosidase more than 50%. Regarding the lipase assay, DCM and Hex had the best activity (31.5 ± 14.3 and 44.3 ± 4.5 μg mL-1, respectively). Various biomolecules known as potent antioxidants were identified in these fractions, such as quercetin, kaempferol, luteolin and (Epi)catechin. S. cumini fractions and quercetin presented promising antioxidant and antiglycation properties as well as the ability to inhibit digestive enzymes. This study presents new biological activities not yet described for S. cumini which provide new possibilities for further studies in order to assess the antidiabetic potential of S. cumini fractions especially EtOAc and ButOH.

Franco RR ，Ribeiro Zabisky LF ，Pires de Lima Júnior J ，Mota Alves VH ，Justino AB ，Saraiva AL ，Goulart LR ，Espindola FS ... -  《-》

Anacardium humile St. Hil as a novel source of antioxidant, antiglycation and α-amylase inhibitors molecules with potential for management of oxidative stress and diabetes.

The substantial increase in diabetes cases worldwide has been a major public health problem, and the use of medicinal plants can be considered an interesting alternative to control the disease and its complications. Anacardium humile St. Hill. (Anacardiaceae) is a typical plant from the Brazilian savanna, popularly known for its antidiarrheal, expectorant, antidiabetic and anti-inflammatory properties, however, few studies have fully described its biological properties. This study aimed to investigate in vitro and ex vivo the antioxidant and antiglycation potential of A. humile ethanolic extract, its organic fractions and three isolated molecules (quercetin, catechin and gallic acid), their capacity to inhibit the glycolytic enzyme α-amylase, as well as their cytotoxic effects against RAW264.7 macrophages. The ethanolic extract of A. humile, its organic fractions and three isolated molecules (catechin, quercetin and gallic acid) were tested for their antioxidant (ORAC, FRAP and DPPH) and antiglycation (BSA/Fructose, BSA/Methylglyoxal, Arginine/Methylglyoxal and Lysine/Methylglyoxal) capacities, and also for its potential to inhibit the enzyme α-amylase. Additionally, bioactive compounds present in the A. humile leaves fractions were elucidated by an HPLC-ESIMS/MS analysis. The analysis showed relevant antioxidant activity of DCM (1264.85 ± 76.90 μM Trolox eq/g ORAC; 216.71 ± 1.04 μM Trolox eq/g FRAP and 3.03 ± 0.08 IC50 μg/mL IC50 DPPH) and EtOAc (1300.11 ± 33.04 ORAC, 236.21 ± 23.86 FRAP and 3.03 ± 0.14 μg/mL IC50 DPPH) fractions and also of the isolated molecules, mainly gallic acid (1291.19 ± 8.41 μM Trolox eq/g ORAC, 1103.52 ± 31.48 μM Trolox eq/g FRAP and 0.78 ± 0.11 μg/mL IC50 DPPH). Concerning the antiglycation activity, all samples inhibited over 88% in the BSA-FRU method. In the BSA-MGO and ARG-MGO methods, the Hex, DCM, EtOAc fractions and the isolated molecule catechin stood out. However, in the LYS-MGO model, only the isolated molecules showed significant results. In α-amylase assay, all fractions, for exception Hex, presented notable inhibition capacity with low IC50 values, especially DCM, EtOAc, ButOH and H2O (IC50 0.56 ± 0.10, 0.84 ± 0.01, 0.74 ± 0.03 and 0.79 ± 0.06 μg/mL, respectively). Tests using hepatic tissue showed a notorious capacity of the DCM, AcOEt and ButOH fractions, as well as of the isolated molecules to inhibit lipid peroxidation and ROS production, and also to preserve thiol groups. Molecules of great antioxidant potential were found in our samples, such as kaempferol, quercetin, catechin, gallic acid and luteolin. A. humile extract and its organic fractions showed promising antioxidant and antiglycation potential and a prominent capacity to inhibit the α-amylase enzyme. Hence, this study presents new results and stimulates further research to elucidate the biological properties of A. humile and its capacity to manage DM and its complications.

Lima Júnior JP ，Franco RR ，Saraiva AL ，Moraes IB ，Espindola FS ... -  《-》

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.

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.

Franco RR ，Justino AB ，Martins MM ，Silva CG ，Campana PRV ，Lopes JCD ，De Almeida VL ，Espindola FS ... -  《-》