Identification and Antioxidant Activity of the Extracts of Eugenia uniflora Leaves. Characterization of the Anti-Inflammatory Properties of Aqueous Extract on Diabetes Expression in an Experimental Model of Spontaneous Type 1 Diabetes (NOD Mice)

Abstract

Medical and folklore reports suggest that Eugenia uniflora (E. uniflora) is a functional food that contains numerous compounds in its composition, with anti-inflammatory, antioxidant and anti-diabetic effects. In the present study, we investigated the best solvents (water, ethanol and methanol/acetone) for extracting bioactive compounds of E. uniflora leaves, assessing total phenols and the antioxidant activity of the extracts by 2,2-Diphenyl-1-picrylhydrazyl (DPPH), Ferric Reducing Antioxidant Power (FRAP), 2,2′-Azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and Oxygen Radical Absorbance Capacity (ORAC) assays, identifying hydrolysable tannins and three phenolic compounds (ellagic acid, gallic acid and rutin) present in the leaves. In addition, we evaluated the incidence of diabetes, degree of insulitis, serum insulin, hepatic glutathione and tolerance test glucose in non-obese diabetic (NOD) mice. Our results suggest that the aqueous extract presents antioxidant activity and high total phenols, which were used as a type 1 diabetes mellitus (DM-1) treatment in NOD mice. We verified that the chronic consumption of aqueous extract reduces the inflammatory infiltrate index in pancreatic islets, maintaining serum insulin levels and hepatic glutathione, and reducing serum lipid peroxidation as well as the risk for diabetes.

Antioxidant, antihyperglycemic, and antidyslipidemic effects of Brazilian-native fruit extracts in an animal model of insulin resistance

“…To limit oxidative damage, the body produces antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). Additionally, substances acquired through diet, such as flavonoids, vitamins, and minerals, form an important defense barrier [6,7].…”

Caracterização anatômica e histoquímica das folhas de Eugenia uniflora L.

“…Encontram-se, na literatura, estudos que reportam efeitos antidiarreico (Almeida et al, 1995), antidiabético (Arai et al, 1999), antimicrobiano Biasi-Garbin et al, 2016), antioxidante (Sobral-Souza et al, 2014;Schumacher et al, 2015), hepatoprotetor (Victoria et al, 2013), antinociceptivo e hipotérmico (Amorim et al, 2009), anti-Trypanosoma cruzi (Santos et al, 2012;Azeredo et al, 2014) e antiLeishmania (Rodrigues et al, 2013) para as folhas de E. uniflora.…”

PHYTOCHEMICAL CONSTITUENTS, ANTIOXIDANT AND ANTIMICROBIAL ACTIVITIES OF Eugenia uniflora Linn. LEAF

“…Examples are glutathione peroxidase, catalase and superoxide dismutase while exogenous anti-oxidants are derived from our diet, such as flavonoids, vitamins A, C and E, polyphenols, Phenolic acid, carotenes 13 . Schumacher et al 14 reported that the treatment of type-1-diabetes mellitus in non-obese diabetic (NOD) mice with aqueous extracts of E. uniflora leaf reduce the risk for diabetes as a result of the high antioxidant activity of the extract. Hepatic glutathione and serum insulin levels can be preserved and reduction in serum lipid peroxidation can be obtained in NOD mice, if treated with aqueous extract of E. uniflora leaf 14 .…”

“…Schumacher et al 14 reported that the treatment of type-1-diabetes mellitus in non-obese diabetic (NOD) mice with aqueous extracts of E. uniflora leaf reduce the risk for diabetes as a result of the high antioxidant activity of the extract. Hepatic glutathione and serum insulin levels can be preserved and reduction in serum lipid peroxidation can be obtained in NOD mice, if treated with aqueous extract of E. uniflora leaf 14 . The industrial relevance of the leaves of E. uniflora has been proposed by the antimicrobial properties exhibited by the essential oil extracted from its leaves 15 .…”