Antiglycation Properties Research Articles

Glycoside Hydrolases and Non-Enzymatic Glycation Inhibitory Potential of Viburnum opulus L. Fruit-In Vitro Studies.

Phytochemicals of various origins are of great interest for their antidiabetic potential. In the present study, the inhibitory effects against carbohydrate digestive enzymes and non-enzymatic glycation, antioxidant capacity, and phenolic compounds composition of Viburnum opulus L. fruits have been studied. Crude extract (CE), purified extract (PE), and ethyl acetate (PEAF) and water (PEWF) fractions of PE were used in enzymatic assays to evaluate their inhibitory potential against α-amylase with potato and rice starch as substrate, α-glucosidase using maltose and sucrose as substrate, the antioxidant capacity (ABTS, ORAC and FRAP assays), antiglycation (BSA-fructose and BSA-glucose model) properties. Among four tested samples, PEAF not only had the highest content of total phenolics, but also possessed the strongest α-glucosidase inhibition, antiglycation and antioxidant activities. UPLC analysis revealed that this fraction contained mainly chlorogenic acid, proanthocyanidin oligomers and flavalignans. Contrary, the anti-amylase activity of V. opulus fruits probably occurs due to the presence of proanthocyanidin polymers and chlorogenic acids, especially dicaffeoylquinic acids present in PEWF. All V. opulus samples have an uncompetitive and mixed type inhibition against α-amylase and α-glucosidase, respectively. Considering strong anti-glucosidase, antioxidant and antiglycation activities, V. opulus fruits may find promising applications in nutraceuticals and functional foods with antidiabetic activity.

Antiamylase, Antiglucosidase, and Antiglycation Properties of Millets and Sorghum from Sri Lanka.

The present study evaluated a range of biological activities of selected millet types and sorghum varieties in Sri Lanka in relation to diabetes and its complications management. Five millet types, namely, proso millet, white finger millet, kodo millet, foxtail millet, and finger millet (Oshadha and Rawana), and two sorghum varieties, namely, sweet sorghum and sorghum ICSV 112, were used in this study. Methanolic extracts of whole grains were studied for antiamylase, antiglucosidase, and early- and middle-stage antiglycation and glycation reversing activities in vitro. Tested millets and sorghum showed significant (p < 0.05) and dose-dependent antiamylase (IC50: 33.34 ± 1.11–1446.70 ± 54.10 μg/ml), early-stage antiglycation (IC50: 15.42 ± 0.50–270.03 ± 16.29 μg/ml), middle-stage antiglycation (135.08 ± 12.95–614.54 ± 6.99 μg/ml), early-stage glycation reversing (EC50: 91.82 ± 6.56–783.20 ± 61.70 μg/ml), and middle-stage glycation reversing (393.24 ± 8.68–1374.60 ± 129.30 μg/ml) activities. However, none of the studied millet and sorghum showed antiglucosidase activity. Out of the samples studied, pigmented samples, namely, sweet sorghum, Oshadha, and Rawana, exhibited significantly high (p < 0.05) antiamylase and early- and middle-stage antiglycation and glycation reversing activities compared to other millet and sorghum samples. Interestingly, sweet sorghum exhibited nearly four times potent antiamylase activity compared to the standard drug acarbose (IC50 111.98 ± 2.68 μg/ml) and sweet sorghum, kodo millet, Oshadha, and Rawana showed comparable early-stage antiglycation activities in comparison to the reference standard Rutin (IC50 21.88 ± 0.16 μg/ml). Therefore, consumption of whole grains of pigmented millet and sorghum in Sri Lanka may play an important role in the prevention and management of diabetes and its complications. Interestingly, this is the 1st study to report all the tested biological activities for millet and sorghum in Sri Lanka and the 1st study to report both early- and middle-stage glycation reversing activities of millet and sorghum worldwide.

The amelioration of T2DM rat femoral bone achieved by anti-osteoporosis of caprine CSN1S2 protein through bone morphogenetic protein signaling pathway.

We investigated the potential anti-glycation and anti-osteoporosis properties of Caprine milk CSN1S2 protein on the serum AGEs and sRAGE level, osteogenic factors expressions, femoral bone mesostructure, histomorphometry, and hydroxyapatite crystals changes in T2DM rats. Varying doses of Caprine milk CSN1S2 protein (0, 375, 750, and 1500 mg/kg BW) were used to treat the control and T2DM rats. We measured AGEs and sRAGE level; RUNX2, OSX, BMP2, and Caspase-3 expressions in rats using ELISA and immunohistochemistry, respectively. The mesostructure and histomorphometry of femoral bone was analyzed using SEM Microscope and BoneJ software, then hydroxyapatite crystal size was determined using SEM-XRD. T2DM rats showed a high level of AGEs and a low level of sRAGE, the RUNX2, OSX, and BMP2 expression was down regulated, BV, BV.TV, Tb.Th, Tb.Sp, increased and SMI levels declined, respectively. Vice versa, after administration of the CSN1S2 protein to T2DM rats, improvement in all levels of molecular and cellular markers was achieved. In the CSN1S2 highest dose, AGEs level declined and sRAGE level elevated in T2DM rats. The 375 and 750 mg/kgBW of CSN1S2 protein was able to upregulate the RUNX2, OSX, and BMP2 expression in T2DM rats, thus improving the normalization of osteoclasts and osteoblasts number. The whole dose of CSN1S2 triggered the thickening of trabecular bone wall, granule formation, and normalized the trabecular thickness (Tb.Th) parameter of T2DM rats. The hydroxyapatite crystal size was increased in the highest dose of CSN1S2-treated T2DM rats. This study indicated that CSN1S2 protein had a protective effect against osteoporosis in the T2DM rat bones by means of glycation pathway inhibition, bone histomorphometry and mesostructure improvement via bone morphometric protein signaling.

Antioxidant and anti-advanced glycation end products formation properties of palmatine

Context: Oxidative stress and formation of advanced glycation end products (AGEs), due to glycation of proteins, lipids and nucleic acids are characteristic in diabetic patients. Palmatine, a protoberberine alkaloid bioactive isolated from Coscinium fenestratum (CF) stem extract, which previously has shown to possess antidiabetic and antioxidant properties and to be able to protect the kidney and liver in a STZ-diabetic induced rat model. Aims: To evaluate the in vitro and in vivo antioxidant and anti-AGE activity of palmatine. Methods: In vitro and in vivo studies were conducted to measure radical scavenging, reducing power, inhibition of lipid peroxidation, carbonyl trapping and metal ion chelation. In vitro antiglycation activity was done using bovine serum albumin-methylglyoxal (BSA-MGO), bovine serum albumin – glucose (BSA-GLU) and glycated hemoglobin. In vivo antioxidant and antiglycation activity were used to evaluate liver and kidney extracted from STZ-induced diabetic rat after treatment with palmatine. Results: The results showed palmatine blocked the formation of AGE as shown by the results of BSA-GLU, BSA-MGO, glycated hemoglobin and inhibited the free radicals generated by DPPH, nitric oxide, hydrogen peroxide, lipid peroxidation, FRAP and metal ion chelating. It was able to stimulate in vivo the activity of catalase, super oxide dismutase and glutathione peroxidase. Conclusions: Palmatine possess antioxidant and antiglycation properties, the mechanism of action seems to be via the blockage of free radical formation, decreasing of reactive carbonyl. Further research is ongoing to determine the effect of palmatine on glyoxalase 1 and aldose reductase pathway and interaction with receptor for AGE.

Clove (Syzygium aromaticum) spices: a review on their bioactivities, current use, and potential application in dairy products

Clove is a common spice used as a flavorant and natural preservative in food industries due to its rich phenolic constituents like eugenol and eugenol acetate etc. These phenolic constituents possess enormous antioxidant activities, anti-glycation, antinociceptive and antimicrobial properties which enhanced the bioactivities of clove spices. Several in vitro and in vivo assays have been conducted to ascertain the potentials of clove spices as well as its cytotoxicity. Due to its beneficial effects, clove spices have been applied for use in agriculture as insecticides, anesthesia, antioxidants etc. In general, methods used for processing of herbs and spices including clove spices are drying, solvent extraction, microwave assisted extraction, supercritical carbondioxide extraction, ultrasound assisted extraction and microencapsulation. All of these were reviewed and presented in this article. Previous findings on application of spices and herbs in dairy products were eye-opener which suggested that clove spices could be incorporated into dairy products. Consequently, it will help to promote clove spices as potential nutraceutical and food additive in different foods particularly in dairy products.

497 A Dunaliella salina extract counteracts skin aging under intense solar irradiation thanks to its anti-glycation and anti-inflammatory properties

497 A Dunaliella salina extract counteracts skin aging under intense solar irradiation thanks to its anti-glycation and anti-inflammatory properties

Sulfated polysaccharides from red seaweed Gelidium amansii: Structural characteristics, anti-oxidant and anti-glycation properties, and development of bioactive films

Marine red algae are rich sources of sulfated polysaccharides as bioactive ingredients and hydrocolloid molecules. In this study, sulfated polysaccharides (YGAP, EGAP, and NGAP) were extracted from Gelidium amansiis that were harvested from three different sea areas of China. Characterization of these polysaccharides shows that they contain 3.7–4.0% sulfate and are mainly composed of galactose, glucose, fucose, arabinose, and mannose. The FT-IR and 13C NMR analysis indicate that the sulfated polysaccharides are agar-type galactans containing 3,6 anhydro-α-l-galactopyranose and β-d-galactopyranose residues. By using various in vitro models, all sulfated polysaccharides, particularly EGAP, exhibit the ability to scavenge O2•– and OH· radicals and reducing power. Additionally, in a glucose-glycated BSA system, the polysaccharides show an inhibitory effect on protein glycation and formation of specific advanced glycation end-product. Their anti-glycative property is attributed to their anti-oxidant activity and trapping capacity of methylglyoxal. Given that these polysaccharides possess agar-like structures, they were used to prepare bioactive films and expectedly, transparent and homogeneous films were obtained. The films display high water barrier properties with retained antioxidant and anti-glycation activities as above. These results expand the current knowledge of G. amansiis polysaccharides as nutraceuticals and hydrocolloids, which would benefit their applications in the food industry.

Effect of Olea europaea L. and Juglans regia L. Extracts on Human Cancer Cell Line Viability with Studying of Hypoglycemic and Antiglycation Properties

There is an urgent and continuous need to discover new sources of medicinal plants to obtain useful compounds with health properties. So the purpose of this study was to investigate activity of Olea europaea L and Juglans regia leaves extract on Hela cell line viability, antidiabetic and Antiglycation. The aqueous extracts were obtained from leaves. Alloxan 180 mg /kg body was used to induce diabetes. Mice with blood glucose level of ≥200 mg/dl were considered as diabetic and were received 10 mg/kg of body weight of Extracts. For Antiglycation, SDS-PAGE (sodium dodecyl sulphate–polyacrylamide gel electrophoresis) were prepared for the appearance of high molecular weight products. Hela cell line were cultured in RPMI-1640 medium for MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay analysis. The results showed that the mean of glucose levels decreasing in mice that treated with 10 mg/Kg extracts of O. europaea and J. regia. Also SDS-PAGE showed that extracts of J. regia were better than of O. europaea in inhibition of glycation induced protein cross-linking at all studied concentrations. MTT assay showed that the Cytotoxicity was increased with increasing the doses of extract and the cytotoxic effects of J.regia extract were higher than O.europaea at all concentrations. This study showed promising results.

Anti-Cancer Effects of Carnosine-A Dipeptide Molecule.

Background: Carnosine is a dipeptide molecule (β-alanyl-l-histidine) with anti-inflammatory, antioxidant, anti-glycation, and chelating properties. It is used in exercise physiology as a food supplement to increase performance; however, in vitro evidence suggests that carnosine may exhibit anti-cancer properties. Methods: In this study, we investigated the effect of carnosine on breast, ovarian, colon, and leukemic cancer cell proliferation. We further examined U937 promonocytic, human myeloid leukemia cell phenotype, gene expression, and cytokine secretion to determine if these are linked to carnosine’s anti-proliferative properties. Results: Carnosine (1) inhibits breast, ovarian, colon, and leukemic cancer cell proliferation; (2) upregulates expression of pro-inflammatory molecules; (3) modulates cytokine secretion; and (4) alters U937 differentiation and phenotype. Conclusion: These effects may have implications for a role for carnosine in anti-cancer therapy.

Protective role of Clitoria ternatea L. flower extract on methylglyoxal-induced protein glycation and oxidative damage to DNA

BackgroundMethylglyoxal (MG) is a highly reactive dicarbonyl precursor for the formation of advanced glycation end products (AGEs) associated with age-related diseases, including diabetes and its complications. Clitoria ternatea L. flower has been reported to possess antioxidant and antiglycating properties. Evidence indicates that the extract of Clitoria ternatea L. flower inhibits fructose-induced protein glycation and oxidative damage to bovine serum albumin (BSA). However, there is no evidence to support the inhibitory effect of CTE against MG-mediated protein glycation and oxidative damage to protein and DNA. Therefore, the aim of the present study was to investigate whether C. ternatea flower extract (CTE) prevents MG-induced protein glycation and oxidative DNA damage.MethodsThe formation of fluorescent AGEs in BSA was evaluated using spectrofluorometer. The protein carbonyl and thiol group content were used for detecting protein oxidation. DNA strand breakage in a glycation model comprising of MG, lysine and Cu2+ or a free radical generator 2,2′-azobis(2-methylpropionamidine) dihydrochloride (AAPH) systems was investigated using gel electrophoresis. Generation of superoxide anions and hydroxyl radicals in the MG/lysine system was assessed by the cytochrome c reduction assay and thiobarbituric acid reactive substances assay, respectively. High performance liquid chromatography (HPLC) was used to measure the MG-trapping ability.ResultsIn the BSA/MG system, CTE (0.25–1 mg/mL) significantly inhibited the formation of fluorescent AGEs and protein oxidation by reducing protein carbonyl content as well as preventing the protein thiol depletion. The concentration of CTE at 0.125–1 mg/mL prevented oxidative DNA cleavage in MG/lysine and AAPH systems associated with the inhibition of superoxide anion and hydroxyl radical formation. It also directly trapped MG in a concentration-dependent manner, ranging from 15 to 43%.ConclusionsThe study findings suggest that the direct carbonyl trapping ability and the free radical scavenging activity of CTE are the underlying mechanisms responsible for the prevention of protein glycation and oxidative DNA damage.

Polyphenol-rich Indian ginger cultivars ameliorate GLUT4 activity in C2C12 cells, inhibit diabetes-related enzymes and LPS-induced inflammation: An in vitro study.

Diabetes is a chronic metabolic disorder that results in distorted insulin signaling and microvascular complications. Current antidiabetic drugs possess harmful long term side effects, necessitating the need for alternate or compliment therapy with lesser issues. Medicinal plants such as ginger have been reported to possess several beneficial activities including antidiabetic activity. The antidiabetic efficacy of microwave-assisted polyphenolic extracts of Indian ginger cultivars from Odisha (MPO) and Tamil Nadu (MPT) is reported here. MPT and MPO showed insulin stimulated glucose uptake of 1.74±0.25 and 1.47±0.15 fold at 6.25µg/ml of concentrations in C2C12 cells respectively when compared to control. MPT possessed α-amylase, α-glucosidase inhibitory and anti-glycation properties. It also showed DPPH radical scavenging activity (7.69±0.001%), inhibited LPS-induced nitric oxide production (1.06±0.004 fold) than the latter and increased the GLUT4 protein expression by 1.4 fold. Major active compounds such as shogaol and gingerol derivatives, curcumene, zingiberone were identified through GC-ESI/MS analysis and D-pinitol (cyclitol) was identified through HPLC analysis in this variety. This is the first paper to report the presence of an antidiabetic compound, D-pinitol, in the ginger variety. Polyphenol rich, biologically potent ginger extracts can be a good food and nutraceutical supplement to address diabetes and related complications. PRACTICAL APPLICATIONS: Ginger is a native spice of South Asian Countries including India. Ginger extracts possess several medicinal properties such as anti-inflammatory, antidiabetic and antioxidant activities. It is used to treat nausea, vomiting and commonly used as a food flavouring agent and dietary food supplement. Our study shows the antidiabetic, anti-glycation and antioxidant efficacy of polyphenol rich Indian ginger cultivars grown in different geographical regions. Variations in the biological activities between the MPT and MPO ginger variety was observed. Different environmental conditions and their corresponding metabolite accumulation can be correlated with the better activity shown by MPT variety. It showed an increased GLUT4 expression even at a lower dose of 6.25µg/ml. Ginger cultivar, especially MPT variety can be used as an adjuvant therapy for treating diabetes. Therefore, our study indicates that polyphenols rich ginger cultivar has major application in functional food product development.

Oridonin Attenuates the Effects of Chronic Alcohol Consumption Inducing Oxidative, Glycative and Inflammatory Injury in the Mouse Liver.

Oridonin (Ori) is a diterpenoid naturally present in medicinal plants with a potential as an antioxidant agent. This study aimed to evaluate the hepatic anti-oxidative, anti-glycative and anti-inflammatory properties of Ori at 0.125 and 0.25% against chronic ethanol intake in mice. Mice were divided into five groups: i) normal diet group, ii) Ori group, iii) ethanol diet (Lieber-DeCarli liquid diet with ethanol) group, iv) ethanol diet plus 0.125% Ori and v) ethanol diet plus 0.25% Ori. After 8 weeks of Ori supplementation, blood and liver tissue were used for analyses. Ethanol increased the production of reactive oxygen species and nitric oxide, decreased glutathione content, and lowered the activity of glutathione peroxide, glutathione reductase and catalase. Ethanol suppressed the hepatic mRNA expression of nuclear factor E2-related factor 2. Ori supplements reversed these changes. Ethanol increased hepatic Ne-(carboxyethymethyl)-lysine (CML) and pentosidine levels, and enhanced aldose reductase (AR) activity and mRNA expression. Ori supplements at only 0.25% decreased CML and pentosidine levels, and lowered the AR activity as well as its mRNA expression. Ethanol increased the hepatic release of tumor necrosis factor-alpha, transforming growth factor-beta1, interleukin (IL)-1beta and IL-6. Histological data showed that ethanol induced necrosis and inflammatory cell infiltration, while Ori supplements alleviated these inflammatory responses. Ethanol up-regulated the hepatic mRNA expression of nuclear factor kappa B, myeloperoxidase and p38. Ori supplements reversed these changes. These novel findings suggest that Ori could be used as a potent agent against alcohol-induced hepatotoxicity.

Prediction of Antiglycation Activity by Calculating the Energies of Frontier Molecular Orbitals for New 4-Hydroxy-1,4-Dihydroazolo[5,1-c]-1,2,4-Triazines Used as an Example

Protein glycation and the formation of advanced glycation end products (AGEs) play an important role in the pathogenesis of diabetes mellitus (DM) complications, neurodegenerations, and age-related diseases. A model to predict antiglycation activity can reduce the costs and increase the productivity and quality of preclinical screening studies of new compounds. Azolo[5,1-c][1,2,4]triazines and azolo[1,5-a]pyrimidines are well known as biologically active compounds, which additionally have antiglycation properties. A number of 4-hydroxy-4H-azolo-1,4-dihydro[5.1-c]-1,2,4-triazines were selected for designing a prediction model. Azolotriazine derivatives were found to exert an antiglycation effect, inhibiting glycation of bovine serum albumin (BSA) with glucose and specific END fluorescence with equal or greater efficiency as compared with aminoguanidine. The activity range at 1000 μM was estimated at 23.0–71.6% for variously substituted derivatives (30.3 ± 1.2% for aminoguanidine). The highest activity was observed for 4-hydroxy-3-cyano-1,4-dihydro-1,2,4-triazolo[5.1-c]1,2,4-triazine. In all but one compound (aminoguanidine), antiglycation activity correlated with the energy difference ∆(HOMO – LUMO) between the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO); the difference was established by a PM3 semiempirical method. Artificial neural network modeling was used to develop a mathematical model that describes the dependence of antiglycation activity on the calculated energies. The ELUMO and ∆(HOMO – LUMO) energies were found to make the largest contribution to the activity. The model can be used to predict antiglycation activity.

Antioxidative and Antiglycative Properties of Mycosporine-Like Amino Acids-Containing Aqueous Extracts Derived from Edible Terrestrial Cyanobacteria.

The terrestrial filamentous cyanobacterium, Nostoc commune, has been used as a food source in many countries, especially countries in Asia. In this study, N. commune-derived aqueous extracts were evaluated with regard to their antioxidative and antiglycative properties. The antioxidative activity was significantly higher in N. commune colonies isolated from the field than in extracts from colonies cultured in the laboratory. The antioxidative compound content of extracts, including phenolic compounds and phycobiliproteins, was correlated with their antioxidative power. In addition, two mycosporine-like amino acids (MAAs), specifically detected in colonies isolated from the field, were purified. In addition to assessing their antioxidative properties, the antiglycative activity of these MAAs was also assessed. Their inhibitory effects on glycation-dependent protein cross-linking might contribute to the antiglycative power of the extract prepared from field colonies. Taken together, the results from this study revealed that N. commune may have beneficial properties for functional food applications, both by preventing oxidative stress and suppressing the formation of advanced glycation end-products.

The effects of fermentation with lactic acid bacteria on the antioxidant and anti-glycation properties of edible cyanobacteria and microalgae

Cyanobacteria and microalgae-derived food supplements have gained attention in recent times, owing to their antioxidant, hypolipidemic, and anti-obesity effects. In the present study, we analysed the antioxidant and anti-glycation activities of 12 aqueous extract solutions (AESs) of 10 species of cyanobacteria and microalgae. The AESs of the microalgae Dunaliella tertiolecta and Pleurochrysis carterae showed strong ferric-reducing powers, superoxide anion (O2−) radical scavenging capacity, and anti-glycation activity in a bovine serum albumin (BSA)-fructose model. Wild Nostoc commune (cyanobacteria) and sake lees cultured Euglena sp. (microalga) could be fermented by Lactococcus lactis subsp. lactis Uruma-SU1, whereas normal cultured N. commune and Euglena could not. The O2− radical-scavenging capacity and anti-glycation activity in the BSA-methylglyoxal model of the fermented wild N. commune and sake lees cultured Euglena samples were higher than those of the other samples. As advanced glycation end products and reactive oxygen species induce age-related diseases, our study illustrates the health-promoting properties of D. tertiolecta and P. carterae and lactic acid bacteria-fermented wild N. commune and sake lees cultured Euglena sp.; moreover, it communicates their importance as nutritional food materials.

Vanillin Prevents Doxorubicin-Induced Apoptosis and Oxidative Stress in Rat H9c2 Cardiomyocytes

Doxorubicin (doxo) is an effective anticancer compound in several tumor types. However, as a consequence of oxidative stress induction and ROS overproduction, its high cardiotoxicity demands urgent attention. Vanillin possesses antioxidant, antiproliferative, antidepressant and anti-glycating properties. Therefore, we investigated the potential vanillin protective effects against doxo-induced cardiotoxicity in H9c2 cells. Using multiparametric approach, we demonstrated that vanillin restored both cell viability and damage in response to doxo exposure. Contextually, vanillin decreased sub-G1 appearance and caspase-3 and PARP1 activation, reducing the doxo-related apoptosis induction. From a mechanistic point of view, vanillin hindered doxo-induced ROS accumulation and impaired the ERK phosphorylation. Notably, besides the cardioprotective effects, vanillin did not counteract the doxo effectiveness in osteosarcoma cells. Taken together, our results suggest that vanillin ameliorates doxo-induced toxicity in H9c2 cells, opening new avenues for developing alternative therapeutic approaches to prevent the anthracycline-related cardiotoxicity and to improve the long-term outcome of antineoplastic treatment.

Antioxidant and Antiglycation Properties of Seventeen Fruit Teas Obtained from One Manufacturer

The antioxidant activity of teas depends on the type and quality of the ingredients used in the process of tea production, location of the crops, and manner of the raw material processing. Our study is the first to compare the antioxidant and antiglycation properties of seventeen fruit teas obtained from one manufacturer. We evaluated three different brewing times (3, 5, and 10 min) and two brewing temperatures (70 and 100 °C). We demonstrated that infusions with the longest brewing time reveal the highest antiradical activity, while increased brewing temperature does not significantly affect the assessed parameters. The best antioxidant properties were obtained for the teas made from lemon balm with pear, forest fruits, cranberry with pomegranate, raspberry, and raspberry with linden. Fruit teas owe their high antioxidant activity to the presence of polyphenolic compounds in infusions. Extracts from fruit teas also diminish the oxidation and glycation of albumin in vitro, observed as a decrease in the fluorescence of aromatic amino acids and advanced glycation (AGE) and oxidation (AOPP) protein products levels. In conclusion, in order to prepare fruit teas with the best antioxidant properties, a longer extraction time is needed. The health-promoting properties of dried fruit infusions can be modified by changing the qualitative and quantitative composition of the ingredients.

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

Ethnopharmacological relevancePlant 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 methodsEthnobotanical 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. ResultsOur 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. ConclusionS. 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.

Using HPLC and multivariate analyses to investigate variations in the polyphenolic compounds as well as antioxidant and antiglycative activities of some Lamiaceae species native to Iran

The Lamiaceae family is a major source of species among medicinal plants that are highly valued for their antioxidant properties and multiple pharmaceutical uses in folk medicine. Satureja, Origanum, and Dracocephalum are some of the major genera belonging to the Lamiaceae family. The present study used seven Iranian endemic species of the Lamiaceae family, viz. one from each of S. hortensis, S. bachtiarica, S. sahendica, and D. kotschyi species as well as three ecotypes from O. vulgare and compared them in terms of their antioxidant activities. S. hortensis exhibited the highest total phenolic (266.82 mg Tannic acid/g DW) and total flavonoid (22.63 mg Quercetin/g DW) contents with the highest antioxidant activity (IC50 = 95.52 μg/mL), while the least activity was recorded for the aqueous extract of Origanum. High performance liquid chromatography (HPLC) was also performed to determine the major polyphenols. Rosmarinic acid was identified as the predominant phenolic compound in all the studied Lamiaceae species. Three Satureja species richer in phenolics and flavonoids with a substantial antioxidant activity were also selected to investigate their antiglycation properties. For comparison, the antiglycative activity was also assessed in bovine serum albumin/methylglyoxal system. The highest and lowest anti-glycative activities were recorded for S. hortensis and S. sahendica, respectively. Finally, S. hortensis was found to produce the highest amounts of such polyphenols as rosmarinic, syringic, caffeic, and ferulic acids basically considered to be the main phenolic acids responsible for the antioxidant and anti-glycative activities of the plant extracts.

Screening and Characterization of Antiglycoxidant Anthocyanins from Vaccinium myrtillus Fruit Using DPPH and Methylglyoxal Pre-Column HPLC Assays.

Vaccinium myrtillus fruit (bilberry) is well known for its high richness in anthocyanins, which may be responsible for its preventive effects on several oxidative and carbonyl stress-related pathologies. However, limited data are available regarding the antioxidant and antiglycative contributions of its constituents. Spectrometric analyses were performed to evaluate anthocyanin content, radical scavenging and antiglycative properties of an anthocyanin-rich extract from bilberries. Additionally, original DPPH and methylglyoxal pre-column HPLC methods were instigated to allow straightforward identification of the main contributors to radical and carbonyl trapping effects. Finally, representative pure anthocyanins were evaluated using classical DPPH and antiglycation assays. Delphinidin, petunidin and cyanidin glycosides were identified as the most effective radical scavenging constituents in both HPLC and spectrometric DPPH evaluations. Potent antiglycative activities were also assessed for cyanidin, delphinidin and petunidin glucosides as attested by their respective IC50 values of 114.2 ± 7.8, 130.5 ± 2.8, and 132.4 ± 3.7 µM. Interestingly, methylglyoxal spiking evaluation demonstrated that all bilberry anthocyanins exerted noticeable and comparable α-dicarbonyl trapping effects. Anthocyanins can be regarded as potent antiglycoxidant agents that might account for some health benefits of bilberries consumption. Besides, significant differences in their contributions were successfully highlighted by the employed pre-column HPLC assays.