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

ETHNOPHARMACOLOGICAL RELEVANCE: 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. MATERIAL AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Antidiabetic potential of Bauhinia forficata Link leaves: a non-cytotoxic source of lipase and glycoside hydrolases inhibitors and molecules with antioxidant and antiglycation properties.

Bauhinia forficata Link., a cerrado native plant, is used as a complementary treatment for Type 2 Diabetes Mellitus (T2DM). Several studies involving this plant have shown that it has prominent potential to combat hyperglycemia and oxidative stress. Our objective was suggest the phytochemical constitution of fractions of ethanol extract of B. forficata leaves using HPLC-ESI-MS/MS, and evaluates their activities in enzymatic assays to evaluate their inhibitory potential against α-amylase, α-glucosidase and lipase, as well as their antioxidant and anti-glycation capacities. In addition, we evaluated the cytotoxic effects of these fractions using rodents macrophages and erythrocytes. The ETOAC e ButOH fractions showed high polyphenols concentrations, having been determined 11 flavonoids, including the kaempferitrin, the phytomarker of B. forficata Link. In addition, all fractions presented higher antioxidant and antiglycation activities and prominent capacities to digestive enzymes inhibition. On the other hand, in the cellular assays, none fractions showed cytotoxic and hemolytic effects, able to combat the ROS production in macrophages. Thus, this study presented new results on the biological activities of this plant, contributing to the understanding of the action and effectiveness of its use in the management of diabetes mellitus and its complications.