The botanical extracts of Achyrocline satureoides and Ilex paraguariensis prevent methylglyoxal-induced inhibition of plasminogen and antithrombin III

Inhibition of Glycation End Products Formation and Antioxidant Activities of Ilex paraguariensis: comparative study of fruit and leaves extracts

Objectives

Ilex paraguariensis (Aquifoleaceae) is cultivated to produce "yerba mate". Due to its nutritional, energizing, hypoglycemic and antioxidant effects, it is used in the elaboration of food, pharmaceuticals, and cosmetics. The oxidative stress related to protein glycation and production of advanced glycation end products (AGEs) leads to the development of several diseases. The objective of this work was to compare the antioxidant and anti-AGEs activity of a decoction of fruits (F) and leaves (L).

Methods

The antioxidant activity was assayed by the DPPH assay and the inhibition of egg yolk lipid peroxidation (ILP), and anti-AGEs activity, through the inhibition of the formation of fructosamine (IF), β-amyloid (Iβ), protein carbonylation (IC) and AGEs (IA). Polyphenols were quantified by HPLC.

Results

Maximum response ± SEM For F 0.01 µg/mL IF = 42 ± 4%, IC = 17 ± 2% and for 10 µg/mL IA = 38 ± 4%, Iβ = 67 ± 7%. For L 0.1 µg/mL IF = 35 ± 2%, IC = 19 ± 2% and for 100 µg/mL IA = 26 ± 3%, Iβ = 63.04 ± 2%. The DPPH IC50 = 134.8 ± 14 µg/mL for F and 34.67 ± 3 µg/mL for L. The ILP IC50 = 512.86 ± 50 µg/mL for F and 154.8 ± 15 µg/mL for L. By HPLC L presented the highest amounts of flavonoids and caffeoylquinic acids. F and L showed strong anti-AGEs activity, affecting the early stages of glycation at low concentrations and the late stages of glycation at high concentrations. The highest activity for both F and L was seen in the IF and Iβ. F presented the highest anti-AGEs potency. L presented the highest antioxidant potency, which was related to the highest content of polyphenols.

Conclusion

The fruits of I. paraguariensis could be a source of antioxidant and anti-AGEs compounds to be used with medicinal purposes or as functional food.

Anti-hyperglycaemic effect and nutritional properties of an aqueous extract of Larrea divaricata Cav. (jarilla) in streptozotocin-induced diabetes in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Larrea divaricata Cav. (Zygophyllaceae) (jarilla) is a native plant of South America widely distributed across Argentina and used in popular medicine to treat diabetes and hypercholesterolemia by the Diaguita-Calchaquí, Amaichas, and Quilmes indigenous communities and by non-indigenous population (criollos) of Calamuchita, in the province of Córdoba, Argentina. L. divaricata has also proved to have anti-inflammatory properties. However, the antidiabetic effects and the nutritional properties of the aqueous extract (AE) of this plant remain to be scientifically determined.

AIM OF THE STUDY

The aim of the present work was to evaluate the capacity of an aqueous extract of L. divaricata (AE) and its main compound nordihydroguaiaretic acid (NDGA) to modulate the glucose, cholesterol, triglycerides and oxidative stress levels in STZ-induced diabetes in mice. The general objective of the present work was to search for extracts that can be used as adjuvant therapy in for diabetes. The suitability of the extract to be used as a dietary supplement was also assessed by determining the proximate amount of fibre, lipids, proteins, and minerals.

MATERIALS AND METHODS

Diabetes was induced in mice by administration of streptozotocin (STZ). AE and NDGA were administered by the oral route. The animals' glycaemia was periodically monitored in blood samples obtained from the tail vein. The glucose dehydrogenase method was used. The effect of the AE on cholesterol, triglycerides, oxidative stress, lipid peroxidation and reduced glutathione (GSH) levels were determined in plasma samples by spectrophotometric assays.

RESULTS

In STZ-treated mice, AE significantly decreased glucose (33%, ****p < 0.0001) and cholesterol levels (32%, **p < 0.01). AE and NDGA decreased lipid peroxidation (30% and 38%, respectively, ****p < 0.0001), and increased GSH levels (20%, **p < 0.01). The effects of AE on glucose and lipid levels could not be ascribed to NDGA; however, this compound was involved in the extract antioxidant effects. The overall effects of AE were probably related to its antioxidant activity and to the anti-hyperglycaemic effect mainly mediated by flavonoids, fibre (carbohydrates) and mineral elements such as potassium, calcium, magnesium, and zinc. The AE protein content also confers the extract nutritional properties.

CONCLUSIONS

These results support the hypothesis that AE could be used as a therapeutic adjuvant or as a nutritional supplement to control glucose levels and lipid metabolism in metabolic syndrome-associated diseases. Moreover, these results scientifically reinforce the popular use of the plant.

Larrea divaricata: anti-inflammatory and antioxidant effects of on macrophages and low density lipoproteins

Background

The oxidized low density lipoprotein (ox-LDL) contributes to inflammation and oxidative stress through the activation of macrophages under hyperglycemia contributing to the development of diabetes mellitus and to atherosclerosis. Plants are a source of effective and innocuous antioxidants. Larrea divaricata Cav. (Zygophyllaceae) is used in Argentina folk medicine for its anti-inflammatory properties.

Methods

The aim of this work was to study the antioxidant and anti-inflammatory effects of the aqueous extract (AE) of L. divaricata on macrophages under glucose stimulation and on human LDL and HDL particles under free radical generators.

Results

AE reduced the lipid peroxidation (17%), nitric oxide (NO) (47-50%), tumor necrosis factor-α (TNF-α) (32%) and free radicals (50%) induced by glucose on macrophages. Also prevented HDL nitration (28%), thus preserving its function and structure and inhibited LDL oxidation. The effect on the nitrosative stress was mainly driven by nordihydroguaiaretic acid (NDGA).

Conclusions

These results suggest a potential usefulness of AE as an adjuvant phytotherapy in patients with diabetes mellitus and atherosclerosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-022-03547-8.

Market Expansion of Caffeine-Containing Products: Italian and Argentinian Yerba Mate Consumer Behavior and Health Perception

Mate is the most consumed beverage in South America. There is interest in expanding yerba mate sales into the old and new markets by promoting its health properties and energizing effects. The research study aims to explore Argentinian and Italian purchasing and consumption behavior and perception of yerba mate. The exploration includes agro-food chain stakeholders’ views, and consumers’ habits, perception, knowledge of yerba mate in relation to other market positioning caffeine-containing products. Data collection includes qualitative method, such as interviews with agro-food chain stakeholders, that is producers, processors, consumers, and quantitative consumer survey. Data collection was carried out in Argentina and in Italy. Results show that in Argentina yerba mate consumption is driven by habit and tradition, and in Italy yerba mate is mostly unknown. Consumers tend to drink yerba mate in Argentina and other caffeine-containing beverages in Italy to socialize, and as source of energy. Consumers have little awareness of yerba mate antioxidant properties. Yerba mate provides the energy of coffee drinking, and the taste and pleasure of tea drinking. Italian consumers’ key challenge to yerba mate drinking is the longer time it takes, compared to the usual espresso. Italians perceive it as an energetic or relaxing beverage, with a consumption experience similar to tea and infusions. There is need to update commercialization strategy of yerba mate in Italy.

Healthy eating recommendations: good for reducing dietary contribution to the body's advanced glycation/lipoxidation end products pool?

The present review aims to give dietary recommendations to reduce the occurrence of the Maillard reaction in foods and in vivo to reduce the body's advanced glycation/lipoxidation end products (AGE/ALE) pool. A healthy diet, food reformulation and good culinary practices may be feasible for achieving the goal. A varied diet rich in fresh vegetables and fruits, non-added sugar beverages containing inhibitors of the Maillard reaction, and foods prepared by steaming and poaching as culinary techniques is recommended. Intake of supplements and novel foods with low sugars, low fats, enriched in bioactive compounds from food and waste able to modulate carbohydrate metabolism and reduce body's AGE/ALE pool is also recommended. In conclusion, the recommendations made for healthy eating by the Spanish Society of Community Nutrition (SENC) and Harvard University seem to be adequate to reduce dietary AGE/ALE, the body's AGE/ALE pool and to achieve sustainable nutrition and health.

A systematic review of antiglycation medicinal plants

BACKGROUND AND OBJECTIVES

The present review shows a list of anti-glycation plants with their anti-glycation activity mechanisms that can attract the attention of pharmacologist for further scientific research towards finding better remedy for diabetic complications.

MATERIALS

Google scholar, Pubmed, Web of Science and Scopus were searched. The terms were advanced glycation end products (AGEs), medicinal plants, antiglycation products.

RESULTS

plants that studied in this review inhibit glycation in several possible mechanisms. Some of these plants inhibit the production of shiff base and amadori products. The others inhibit the generation of amadori products in the advanced phase. Some others blocked the aggregation of AGEs and some plants have antioxidant activity and reduce AGEs formation by preventing oxidation of amadori product and metal-catalyzed glucoxidation.

CONCLUSION

This review can help pharmacologist to find antiglycation natural substance that can be useful in treatment of diabetic complications.

Analysis of radioprotection and antimutagenic effects of Ilex paraguariensis infusion and its component rutin

DNA repair pathways, cell cycle checkpoints, and redox protection systems are essential factors for securing genomic stability. The aim of the present study was to analyze the effect of Ilex paraguariensis (Ip) infusion and one of its polyphenolic components rutin on cellular and molecular damage induced by ionizing radiation. Ip is a beverage drank by most inhabitants of Argentina, Paraguay, Southern Brazil, and Uruguay. The yeast Saccharomyces cerevisiae (SC7Klys 2-3) was used as the eukaryotic model. Exponentially growing cells were exposed to gamma rays (γ) in the presence or absence of Ip or rutin. The concentrations used simulated those found in the habitual infusion. Surviving fractions, mutation frequency, and DNA double-strand breaks (DSB) were determined after treatments. A significant increase in surviving fractions after gamma irradiation was observed following combined exposure to γ+R, or γ+Ip. Upon these concomitant treatments, mutation and DSB frequency decreased significantly. In the mutant strain deficient in MEC1, a significant increase in γ sensitivity and a low effect of rutin on γ-induced chromosomal fragmentation was observed. Results were interpreted in the framework of a model of interaction between radiation-induced free radicals, DNA repair pathways, and checkpoint controls, where the DNA damage that induced activation of MEC1 nodal point of the network could be modulated by Ip components including rutin. Furthermore, ionizing radiation-induced redox cascades can be interrupted by rutin potential and other protectors contained in Ip.

Ilex paraguariensis and its main component chlorogenic acid inhibit fructose formation of advanced glycation endproducts with amino acids at conditions compatible with those in the digestive system

We have previously shown that Ilex paraguariensis extracts have potent antiglycation actions. Associations of excess free fructose consumption with inflammatory diseases have been proposed to be mediated through in situ enteral formation of fructose AGEs, which, after being absorbed may contribute to inflammatory diseases via engagement of RAGE. In this proof of principle investigation we show fluorescent AGE formation between amino acids (Arg, Lys, Gly at 10-50mM) and fructose (10-50mM) under time, temperature, pH and concentrations compatible with the digestive system lumen and its inhibition by Ilex paraguariensis extracts. Incubation of amino acids with fructose (but not glucose) leads to a time dependent formation of AGE fluorescence, already apparent after just 1h incubation, a time frame well compatible with the digestive process. Ilex paraguariensis (mate tea) inhibited AGE formation by 83% at 50μl/ml (p<0.001). Its main phenolics, caffeic acid and cholorogenic acid were as potent as aminoguanidine-a specific antiglycation agent: IC50 of 0.9mM (p<0.001). Our results suggest that AGE adducts form between fructose and amino acids at times and concentrations plausibly found in the intestines. The reaction is inhibited by mate tea and its individual phenolics (caffeic acid and chlorogenic acids). The study provides the first evidence for the proposed mechanism to explain epidemiological correlations between excess fructose consumption and inflammatory diseases. Enteral fructose-AGE formation would be inhibited by co-intake of Ilex paraguariensis, and potentially other beverages, fruits and vegetables that contain comparable concentrations of phenolics as in IP (mate tea).

Note. Caffeine Content and Dynamical Bitterness of Yerba Mate Ilex paraguariensis Infusions

The infusion of yerba mate (YM) Ilex paraguariensis, with its typical bitterness, is traditionally consumed in South America as a mild stimulant beverage. Two types of YM, with sticks (YM-S) and without sticks (YM-L) and three brands for each type were evaluated for caffeine content and the time course of bitterness. The chemical analysis of the six YM infusions at 5% w/v made by high performance liquid chromatography (HPLC) showed that caffeine levels were higher for YM-L brands. The kinetic study of YM bitterness assessed by time-intensity (TI) curves revealed that the presence of sticks lowered maximum intensity, total duration and area under the curve of bitter perception.

Rosemary (Rosmarinus officinalis) as a potential therapeutic plant in metabolic syndrome: a review

Metabolic syndrome is defined by a constellation of complex coexisting cardiometabolic risk factors such as hyperglycemia, dyslipidemia, inflammation, abdominal obesity, coagulopathies, and hypertension that raise the risk of diabetes mellitus and cardiovascular disease. Recently, there has been an increasing interest in the use of herbs and natural compounds in prevention and treatment of diseases and a large number of published articles have focused on this issue. Rosmarinus officinalis L. or rosemary (Lamiaceae) is a rich source of phenolic phytochemicals having significant anti-oxidant, anti-inflammatory, hypoglycemic, hypolipidemic, hypotensive, anti-atherosclerotic, anti-thrombotic, hepatoprotective, and hypocholesterolemic effects. The purpose of this review is to highlight the interesting pharmacological effects of rosemary, and its active compounds, and the related mechanisms in the management of metabolic syndrome that are documented in in vitro and in vivo studies.

Ilex paraguariensis Pellets from a Spray-Dried Extract: Development, Characterization, and Stability

Several studies have shown the potential use of Ilex paraguariensis in developing products with the aim to protect biological systems against oxidative stress-mediated damages. In the same way, technological studies have demonstrated the feasibility of obtaining dry products, by spray-drying process, from aqueous extracts of I. paraguariensis in laboratory. The present work was designed to develop pellets by extrusion/spheronization process, from an I. paraguariensis spray-dried powder. The pellets were characterized with respect to their chemical, physical, and technological properties, and the thermal and the photostability of the main polyphenol constituents were investigated. The pellets exhibited adequate size, shape, and high process yield (78.7%), as well as a good recovery of the total polyphenols (>95%) and a good dissolution in water (89.44 to 100.05%). The polyphenols were stable against light when conditioned in amber glass bottles; unstable against heat when the samples were conditioned either in open glass bottles or in hermetically sealed glass bottles and demonstrated to be hygroscopic and sensible to the temperature, especially when stored in permeable flasks. These findings pointed to the relevance of reducing the residual moisture content of pellets as well as of conditioning them in opaque humidity tight packages under low temperatures. The feasibility of obtaining pellets from an I. paraguariensis spray-dried powder using extrusion/spheronization technique was, for the first time, demonstrated. This finding represents a novelty for the herbal products in both pharmaceutical and food fields.

Anti-obesity effects of Yerba Mate (Ilex Paraguariensis): a randomized, double-blind, placebo-controlled clinical trial

Background

Obesity is a major health problem. A food field research that has recently aroused considerable interest is the potential of natural products to counteract obesity. Yerba Mate may be helpful in reducing body weight and fat. The aim of this study was to investigate the efficacy and safety of Yerba Mate supplementation in Korean subjects with obesity.

Methods

A randomized, double-blind, placebo-controlled trial was conducted. Subjects with obesity (body mass index (BMI) ≥ 25 but < 35 kg/m² and waist-hip ratio (WHR) ≥ 0.90 for men and ≥ 0.85 for women) were given oral supplements of Yerba Mate capsules (n = 15) or placebos (n = 15) for 12 weeks. Subjects take three capsules per each meal, total three times in a day (3 g/day). Measured outcomes were efficacy (abdominal fat distribution, anthropometric parameters and blood lipid profiles) and safety (adverse events, laboratory test results and vital signs).

Results

During 12 weeks of Yerba Mate supplementation, decreases in body fat mass (P = 0.036) and percent body fat (P = 0.030) compared to the placebo group were statistically significant. WHR was significantly decreased (P = 0.004) in the Yerba Mate group compared to the placebo group. No clinically significant changes in any safety parameters were observed.

Conclusions

Yerba Mate supplementation decreased body fat mass, percent body fat and WHR. Yerba Mate was a potent anti-obesity reagent that did not produce significant adverse effects. These results suggested that Yerba Mate supplementation may be effective for treating obese individuals.

Trial registration

ClinicalTrials.gov: (NCT01778257)

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-015-0859-1) contains supplementary material, which is available to authorized users.

Advanced glycation End-products (AGEs): an emerging concern for processed food industries

The global food industry is expected to increase more than US $ 7 trillion by 2014. This rise in processed food sector shows that more and more people are diverging towards modern processed foods. As modern diets are largely heat processed, they are more prone to contain high levels of advanced glycation end products (AGEs). AGEs are a group of complex and heterogeneous compounds which are known as brown and fluorescent cross-linking substances such as pentosidine, non-fluorescent cross-linking products such as methylglyoxal-lysine dimers (MOLD), or non-fluorescent, non-cross linking adducts such as carboxymethyllysine (CML) and pyrraline (a pyrrole aldehyde). The chemistry of the AGEs formation, absorption and bioavailability and their patho-biochemistry particularly in relation to different complications like diabetes and ageing discussed. The concept of AGEs receptor - RAGE is mentioned. AGEs contribute to a variety of microvascular and macrovascular complications through the formation of cross-links between molecules in the basement membrane of the extracellular matrix and by engaging the receptor for advanced glycation end products (RAGE). Different methods of detection and quantification along with types of agents used for the treatment of AGEs are reviewed. Generally, ELISA or LC-MS methods are used for analysis of foods and body fluids, however lack of universally established method highlighted. The inhibitory effect of bioactive components on AGEs by trapping variety of chemical moieties discussed. The emerging evidence about the adverse effects of AGEs makes it necessary to investigate the different therapies to inhibit AGEs.

Dietary advanced glycation end products and their role in health and disease

Over the past 2 decades there has been increasing evidence supporting an important contribution from food-derived advanced glycation end products (AGEs) to the body pool of AGEs and therefore increased oxidative stress and inflammation, processes that play a major role in the causation of chronic diseases. A 3-d symposium (1st Latin American Symposium of AGEs) to discuss this subject took place in Guanajuato, Mexico, on 1-3 October 2014 with the participation of researchers from several countries. This review is a summary of the different presentations and subjects discussed, and it is divided into 4 sections. The first section deals with current general knowledge about AGEs. The second section dwells on mechanisms of action of AGEs, with special emphasis on the receptor for advanced glycation end products and the potential role of AGEs in neurodegenerative diseases. The third section discusses different approaches to decrease the AGE burden. The last section discusses current methodologic problems with measurement of AGEs in different samples. The subject under discussion is complex and extensive and cannot be completely covered in a short review. Therefore, some areas of interest have been left out because of space. However, we hope this review illustrates currently known facts about dietary AGEs as well as pointing out areas that require further research.

The positive effects of yerba maté (Ilex paraguariensis) in obesity

The prevalence of obesity has increased worldwide over the past three decades. Global anti-obesity strategies focus on dietary and lifestyle modifications to slow the development of obesity. Research in the nutrition field has recently aroused considerable interest based on the potential of natural products to counteract obesity. Several studies have identified yerba maté (Ilex paraguariensis) as an excellent candidate. In this review, we evaluated the impact of yerba maté on obesity and obesity-related inflammation. Cellular studies demonstrate that yerba maté suppresses adipocyte differentiation and triglyceride accumulation and reduces inflammation. Animal studies show that yerba maté modulates signaling pathways that regulate adipogenesis, antioxidant, anti-inflammatory and insulin signaling responses. In summary, the data presented here showed that the use of yerba maté might be useful against obesity, improving the lipid parameters in humans and animal models. In addition, yerba maté modulates the expression of genes that are changed in the obese state and restores them to more normal levels of expression. In doing so, it addresses several of the abnormal and disease-causing factors associated with obesity. Protective and ameliorative effects on insulin resistance were also observed. Thus, as a general conclusion, it seems that yerba maté beverages and supplements might be helpful in the battle against obesity.

Recent development of plant products with anti-glycation activity: a review

This review article summarizes the plant natural products that inhibit glycation at different stages leading to the AGEs formation.

The axis AGE-RAGE-soluble RAGE and oxidative stress in chronic kidney disease

Chronic kidney disease (CKD) has been shown to be associated with high oxidative stress and cardiovascular disease. In this chapter our focus will be on the role of advanced glycation end products (AGE) and their receptor, RAGE in CKD progression and their role on cardiovascular complications. We provide a succinct, yet comprehensive summary of the current knowledge, the challenges and the future therapeutic avenues that are stemming out from novel recent findings. We first briefly review glycation and AGE formation and the role of the kidney in their metabolism. Next, we focus on the RAGE, its signaling and role in oxidative stress. We address the possible role of soluble RAGEs as decoys and the controversy regarding this issue. We then provide the latest information on the specific role of both AGE and RAGE in inflammation and perpetuation of kidney damage in diabetes and in CKD without diabetes, which is the main purpose of the review. Finally, we offer an update on new avenues to target the AGE-RAGE axis in CKD.

The hyperglycemic byproduct methylglyoxal impairs anticoagulant activity through covalent adduction of antithrombin III

INTRODUCTION

The blood coagulation system is a tightly regulated balance of procoagulant and anticoagulant factors, disruption of which can cause clinical complications. Diabetics are known to have a hypercoagulable phenotype, along with increased circulating levels of methylglyoxal (MGO) and decreased activity of the anticoagulant plasma protein antithrombin III (ATIII). MGO has been shown to inhibit ATIII activity in vitro, however the mechanism of inhibition is incompletely understood. As such, we designed this study to investigate the kinetics and mechanism of MGO-mediated ATIII inhibition.

METHODS

MGO-mediated ATIII inhibition was confirmed using inverse experiments detecting activity of the ATIII targets thrombin and factor Xa. Fluorogenic assays were performed in both PBS and plasma after incubation of ATIII with MGO, at molar ratios comparable to those observed in the plasma of diabetic patients. LC-coupled tandem mass spectrometry was utilized to investigate the exact mechanism of MGO-mediated ATIII inhibition.

RESULTS AND CONCLUSIONS

MGO concentration-dependently attenuated inhibition of thrombin and factor Xa by ATIII in PBS-based assays, both in the presence and absence of heparin. In addition, MGO concentration-dependently inhibited ATIII activity in a plasma-based system, to the level of plasma completely deficient in ATIII, again both in the presence and absence of heparin. Results from LC-MS/MS experiments revealed that MGO covalently adducts the active site Arg 393 of ATIII through two distinct glyoxalation mechanisms. We posit that active site adduction is the mechanism of MGO-mediated inhibition of ATIII, and thus contributes to the underlying pathophysiology of the diabetic hypercoagulable state and complications thereof.

HPLC-DAD-ESI/MS identification and quantification of phenolic compounds in Ilex paraguariensis beverages and on-line evaluation of individual antioxidant activity

“Chimarrão” and “tererê” are maté (dried, toasted and milled Ilex paraguariensis leaves and stemlets) beverages widely consumed in South America. This paper describes the application of HPLC-DAD-ESI/MS method for the identification and quantification of caffeoylquinic acids (CQA), flavonol glycosides and purine alkaloids in these beverages. The beverage samples were prepared from commercial lots of maté from Southern Brazil. The caffeoylquinic acids, 4,5-diCQA, 3-CQA, 5-CQA, and 4-CQA were the major compounds, having 238–289, 153–242, 183–263, and 123–188 μg/mL, respectively, for chimarrão and 206–265, 122–218, 164–209, 103–169 μg/mL, respectively, for tererê. Caffeine also had high amounts while glycosides of quercetin and kaempferol were found at much lower levels. The individual antioxidant activity was also determined by an on-line system that measured their ABTS^•+ radical scavenging activity, showing that the antioxidant capacity was not proportional to the concentrations of the phenolic compounds. 3-CQA, quercetina-3-O-ramnosylglucoside, and quercetina-3-O-glucoside were the major contributors to the antioxidant capacity, although the quercetin glycosides had concentrations less than 10 times that of 3-CQA.

Modified fast procedure for the detection and screening of antiglycative phytochemicals

In an attempt to elevate temperature to facilitate glycation, a nonenzymatic reaction by incubation of bovine serum albumin (BSA) and fructose at 50 °C for 24 h has been developed. As conducted and compared to a routine procedure by incubation of BSA and fructose at 37 °C for 168 h, the reactant fluorescence intensities and SDS-PAGE-detected glycated BSA quantities produced by both test temperatures increased with time of incubation. As the Amadori products and α-dicarbonyl compounds during incubation were quantified, both quantities produced at each temperature also increased with an increase of time of incubation, and their trends of changes at both temperatures were similar. In practical application for the detection and screening of the antiglycative phytochemicals, each of 20 peanut root extracts was introduced to a series of BSA-fructose solutions and incubated at 37 and 50 °C for 168 and 24 h, correspondingly. All extracts exhibited notable activities and varied depending on peanut origins. Pair comparison of the resultant antiglycative activities determined at 37 and 50 °C showed that both determined activities for each peanut root extract deviated limitedly. As further analyzed, SDS-PAGE-detected glycated BSA quantities formed at 50 °C were closely proportional to the antiglycative activities determined on the basis of their fluorescence intensities. It is of merit to demonstrate that fluorescence-based determination of BSA-fructose reactant after incubation at 50 °C for 24 h is practical and time-saving in the detection and screening of antiglycative phytochemicals.

Naturally occurring inhibitors against the formation of advanced glycation end-products

Advanced glycation end-products (AGEs) are the final products of the non-enzymatic reaction between reducing sugars and amino groups in proteins, lipids and nucleic acids. Recently, the accumulation of AGEs in vivo has been implicated as a major pathogenic process in diabetic complications, atherosclerosis, Alzheimer's disease and normal aging. The early recognition of AGEs can ascend to the late 1960s when a non-enzymatic glycation process was found in human body which is similar to the Maillard reaction. To some extent, AGEs can be regarded as products of the Maillard reaction. This review firstly introduces the Maillard reaction, the formation process of AGEs and harmful effects of AGEs to human health. As AGEs can cause undesirable diseases or disorders, it is necessary to investigate AGE inhibitors to offer a potential therapeutic approach for the prevention of diabetic or other pathogenic complications induced by AGEs. Typical effective AGE inhibitors with different inhibition mechanisms are also reviewed in this paper. Both synthetic compounds and natural products have been evaluated as inhibitors against the formation of AGEs. However, considering toxic or side effects of synthetic molecules present in clinical trials, natural products are more promising to be developed as potent AGE inhibitors.

Metabolic classification of South American Ilex species by NMR-based metabolomics

The genus Ilex to which mate (Ilex paraguariensis) belongs, consists of more than 500 species. A wide range of metabolites including saponins and phenylpropanoids has been reported from Ilex species. However, despite the previous works on the Ilex metabolites, the metabolic similarities between species which can be used for chemotaxonomy of the species are not clear yet. In this study, nuclear magnetic resonance (NMR) spectroscopy-based metabolomics was applied to the classification of 11 South American Ilex species, namely, Ilex argentina, Ilex brasiliensis, Ilex brevicuspis, Ilex dumosa var. dumosa, I. dumosa var. guaranina, Ilex integerrima, Ilex microdonta, I. paraguariensis var. paraguariensis, Ilex pseudobuxus, Ilex taubertiana, and Ilex theezans. (1)H NMR combined with principal component analysis (PCA), partial least square-discriminant analysis (PLS-DA) and hierarchical cluster analysis (HCA) showed a clear separation between species and resulted in four groups based on metabolomic similarities. The signal congestion of (1)H NMR spectra was overcome by the implementation of two-dimensional (2D)-J-resolved and heteronuclear single quantum coherence (HSQC). From the results obtained by 1D- and 2D-NMR-based metabolomics it was concluded that species included in group A (I. paraguariensis) were metabolically characterized by a higher amount of xanthines, and phenolics including phenylpropanoids and flavonoids; group B (I. dumosa var. dumosa and I. dumosa var. guaranina) with oleanane type saponins; group C (I. brasiliensis, I. integerrima, I. pseudobuxus and I. theezans) with arbutin and dicaffeoylquinic acids, and group D (I. argentina, I. brevicuspis, I. microdonta and I. taubertiana) with the highest level of ursane-type saponins. Clear metabolomic discrimination of Ilex species and varieties in this study makes the chemotaxonomic classification of Ilex species possible.

Fractionation of aluminum in commercial green and roasted yerba mate samples ( Ilex paraguariensis St. Hil.) and in their infusions

Different trademarks of green mate and mate tea ( Ilex paraguariensis St. Hil.) were employed in this work, the aim of which was to compare the fractionation of Al from green mate and mate tea (roasted mate) and from their infusions. Using the flame atomic absorption spectrometry technique, contents determined for Al leached to green mate and mate tea infusions varied from 12.8 to 18.1% and from 5.9 to 10.6%, respectively. The concentrations of phenolics in infusions were determined using the Folin-Ciocalteu method, and the presence of melanoidins was also evaluated. The results showed that phenolic compounds are the major contributors to the leached Al in green mate infusions, but melanoidins also contribute in the case of infusions prepared from the mate tea. By employing a chelating resin batch procedure, it was observed that Al was predominantly in relatively inert forms, mainly in the case of mate tea infusions (50-70%).

Conidia production ofBeauveria sp. by solid-state fermentation for biocontrol ofIlex paraguariensis caterpillars

Conidia production of Beauveria sp. strain LAG by solid-state fermentation (SSF) using blends of agro-industrial residues (residual potatoes and sugar-cane bagasse) was optimized with respect to cultivation conditions and the composition of substrate mixture in Erlenmeyer flasks and column-type bioreactor. With a blend of 60 % residual potatoes and 40 % sugar-cane bagasse the optimum conditions achieved were: incubation temperature 26 degrees C, initial substrate pH 6, inoculum concentration 10(7) conidia per g substrate; optimal initial moisture of the substrate was 70 % for Erlenmeyer flasks, in column-type bioreactor (with forced aeration) the optimal initial moisture of the substrate was 65 % with airflow of 60 mL/min. The highest production (1.07 x 10(10) conidia per g dry substrate) was achieved after a 10-d fermentation. The conidia were used in laboratory assays against Thelosia camina and Hylesia sp., caterpillars that are serious pests of mate plants. The mortality of T. camina was >90 % 10 d after spraying caterpillars with 1 mL conidia suspension at a concentration 10(5)-10(8)/mL. For Hylesia sp., the mortality was 70 %, 7 d after immersion in the conidia suspension containing 108 conidia per mL. Therefore, the Beauveria sp. LAG can be considered to be an important biocontrol instrument in the prospect of the Integrated Pest Management for mate plants.

Yerba Mate Tea (Ilex paraguariensis): a comprehensive review on chemistry, health implications, and technological considerations

Yerba Mate tea, an infusion made from the leaves of the tree Ilex paraguariensis, is a widely consumed nonalcoholic beverage in South America which is gaining rapid introduction into the world market, either as tea itself or as ingredient in formulated foods or dietary supplements. The indigenous people have used it for centuries as a social and medicinal beverage. Yerba Mate has been shown to be hypocholesterolemic, hepatoprotective, central nervous system stimulant, diuretic, and to benefit the cardiovascular system. It has also been suggested for obesity management. Yerba Mate protects DNA from oxidation and in vitro low-density lipoprotein lipoperoxidation and has a high antioxidant capacity. It has also been reported that Yerba Mate tea is associated to both the prevention and the cause of some types of cancers. Yerba Mate has gained public attention outside of South America, namely the United States and Europe, and research on this tea has been expanding. This review presents the usage, chemistry, biological activities, health effects, and some technological considerations for processing of Yerba Mate tea. Furthermore, it assesses in a concise and comprehensive way the potential of Ilex paraguariensis as a source of biological compounds for the nutraceutical industry.

Protective effects of mate tea (Ilex paraguariensis) on H2O2-induced DNA damage and DNA repair in mice

Yerba mate (Ilex paraguariensis) is rich in several bioactive compounds that can act as free radical scavengers. Since oxidative DNA damage is involved in various pathological states such as cancer, the aim of this study was to evaluate the antioxidant activity of mate tea as well as the ability to influence DNA repair in male Swiss mice. Forty animals were randomly assigned to four groups. The animals received three different doses of mate tea aqueous extract, 0.5, 1.0 or 2.0 g/kg, for 60 days. After intervention, the liver, kidney and bladder cells were isolated and the DNA damage induced by H(2)O(2) was investigated by the comet assay. The DNA repair process was also investigated for its potential to protect the cells from damage by the same methodology. The data presented here show that mate tea is not genotoxic in liver, kidney and bladder cells. The regular ingestion of mate tea increased the resistance of DNA to H(2)O(2)-induced DNA strand breaks and improved the DNA repair after H(2)O(2) challenge in liver cells, irrespective of the dose ingested. These results suggest that mate tea could protect against DNA damage and enhance the DNA repair activity. Protection may be afforded by the antioxidant activity of the mate tea's bioactive compounds.

Low-density lipoprotein, collagen, and thrombin models reveal that Rosemarinus officinalis L. exhibits potent antiglycative effects

Using the low-density lipoprotein (LDL), collagen, and thrombin models, we report here that the rosemary extracts (REs), either the aqueous (REw) or the acetonic (REA), all possessed many antiglycation-related features, and the effective concentrations required were as follows: 0.1 mg/mL for suppressing the relative electrophoretic mobility, 1.3 microg/mL for anticonjugated diene induction, 0.5 mg/mL for inhibition of thiobarbituric acid reactive substances production, 0.1 mg/mL for AGEs (advanced glycation end products) formation, 0.1 mg/mL to block glucose incorporation, and 0.05 mg/mL as an effective anti-antithrombin III. Using high-performance liquid chromatography/mass spectrometry, we identified five major constituents among eight major peaks, including rosmarinic acid, carnosol, 12-methoxycarnosic acid, carnosic acid, and methyl carnosate. In the LDL model, REA was proven to be more efficient than REw; yet, the reverse is true for the collagen and the thrombin III models, the reason of which was ascribed to the higher lipid-soluble antioxidant content (such as rosmarinic acid, carnosol, carnosic acid, 12-methoxycarnosic acid and methyl carnosate) in REA than in REw and the different surface lipid characteristics between LDL and collagen; although to act as anti-AGEs, both extracts were comparable. To assist the evidence, a larger 2,2-diphenyl-1-picrylhydrazyl radical scavenging capability with less total polyphenolic content was found in REA. We conclude that rosemary is an excellent multifunctional therapeutic herb; by looking at its potential potent antiglycative bioactivity, it may become a good adjuvant medicine for the prevention and treatment of diabetic, cardiovascular, and other neurodegenerative diseases.

Ilex paraguariensis extracts inhibit AGE formation more efficiently than green tea

Glycation, the nonenzymatic adduct formation between sugar dicarbonyls and proteins, is one key molecular basis of diabetic complications due to hyperglycemia. Given the link between glycation and oxidation, we hypothesized that herbal extracts with a high concentration of antioxidant phenolics might possess significant in vitro antiglycation activities as well. The aim of the present study was to address the hypothesis that polyphenol-rich Ilex paraguariensis (IP) extracts are capable of inhibiting advanced glycation end-products (AGEs) formation and to compare the potency of these extracts with green tea and with the standard antiglycation agent aminoguanidine. When we studied the effects of IP extract on AGE fluorescence generated on bovine serum albumin (BSA) by glycation with methylglyoxal, a dose-dependent effect that reaches 40% at 20 mul/ml of extract was demonstrated. Green tea did not display any significant effect. IP polyphenols are about 2- to 2.5-fold higher in our preparations compared with green tea. The effect of IP, therefore, may be due not only to the higher concentrations but to the different composition in phenolics of the two botanical preparations as well. To better discriminate between an antioxidant or a carbonyl quenching mechanism of action, we explored tryptophan fluorescence and cross-linking by sodium dodecyl sulfate polyacrylamide gel (SDS-PAGE) electrophoresis. The conformational changes induced by glycation and substitution of positive charges in arginine and/or lysine produce a decrease in tryptophan fluorescence. We show that incubation of BSA with methylglyoxal produces dramatic changes in tryptophan fluorescence that are prevented by aminoguanidine. This also prevents the downstream effect of AGE formation. Neither green tea nor IP extracts displayed any significant effect which rules out any significant participation as inhibitors in the first phase of the glycation cascade. The results from the SDS-PAGE serve to confirm the above-mentioned data. The effect is therefore due mainly to an inhibition of the second phase of the glycation reactions, namely the free-radical mediated conversion of the Amadori products to AGE. Taken together our results demonstrate a significant, dose-dependent effect of water extracts of I. paraguensis on AGE adducts formation on a protein model in vitro, whereas green tea displays no significant effect. The inhibition of AGE formation was comparable to that obtained by using millimolar concentrations of the standard antiglycation agent aminoguanidine.

Ilex paraguariensis extracts are potent inhibitors of nitrosative stress: A comparative study with green tea and wines using a protein nitration model and mammalian cell cytotoxicity

Due to the increasing importance of nitrosative stress in pathology and the efficacy displayed by flavonoids in cancelling the effects of peroxynitrite, we decided to conduct a comparative study of three commonly used beverages with the highest polyphenol contents and proven antioxidant properties: mate (Ilex paraguariensis); green tea (Camelia sinensis) extracts and white and red wines of the main varietals. We directly evaluated and compared the extracts and wines as protein nitration inhibitors using 3-nitrotyrosine as a biomarker, we studied the extracts as protectors from OONO-induced cytotoxicity in two mammalian cell lines. Both green tea and mate extracts have a high polyphenol content, in the case of Ip, its higher concentration and higher free radical quenching activity on the DPPH assay may be mainly due to the sui generis extraction procedure. When BSA was incubated in the presence of SIN-1, a time and dose dependent nitration of the protein is clearly shown. Co-incubation of BSA with Ip, green tea or red wines led to a dose dependent inhibition of the effect. Ip displayed the highest inhibitory activity, followed by red wines and the green tea. Dilutions as low as 1/1500 produced more than 80% inhibition of albumin nitration. When we studied peroxynitrite-induced cytotoxicity in murine RAW 264.7 macrophages and 31EG4 mammary cells., we found a potent, dose-dependent protective effect that was Ilex paraguariensis > red wines > green tea. Taken together, our results indicate that when the herbal preparations studied here are prepared the way they are usually drunk, Ip displays the highest inhibition of protein nitration, and the highest promotion of cell survival, whereas green tea or red wines display significant but lesser effects at the same concentrations. Further studies aiming at isolation of the active principles and assessment of their bioavailability are warranted.

Cardioprotective effects of Ilex paraguariensis extract: evidence for a nitric oxide-dependent mechanism

AIM

To examine the effects of an Ilex paraguariensis (Ip) extract on postischemic alterations derived from 20 min of global ischemia and 30 min of reperfusion.

METHODS

Isolated rat hearts were treated 10 min before ischemia and the first 10 min of reperfusion with Ip 30 microg/ml. In other hearts, chelerythrine (1 microM), a protein kinase C blocker, or l(G)-nitro l-arginine methyl ester (l-NAME), a nitric oxide synthase inhibitor, were administered prior to Ip infusion. Left ventricular developed pressure (LVDP), +dP/dt(max), -dP/dt(max), and left ventricular end diastolic pressure (LVEDP) were used to assess myocardial function. Thiobarbituric acid reactive substances (TBARS) were measured.

RESULTS

Ip treatment produced an improvement of postichemic recovery (LVDP=96+/-8%; +dP/dt(max)=95+/-10%; -dP/dt(max)=90+/-12% vs. 57+/-6%, 53+/-6% and 57+/-8%, respectively, in untreated hearts) and an attenuation of the increase of LVEDP and TBARS content. Chelerythrine did not modify and l-NAME abolished the protection induced by Ip.

CONCLUSIONS

These data are the first demonstration that Ip extract attenuates the myocardial dysfunction provoked by ischemia and reperfusion and that this cardioprotection involves a diminution of oxidative damage through a nitric oxide-dependent mechanism.

Intervention against the Maillard reaction in vivo

The field of Maillard/glycation reactions in vivo has grown enormously during the past 20 years, going from 25 to 500 publications per year. It is now well recognized that many of the "advanced" products form oxidatively or anaerobically and can have deleterious effects on macromolecular and biological function. The feasibility of developing pharmacological agents with beneficial in vivo properties, based on in vitro inhibition of glycation, has been surprisingly successful. This Editorial sets the stage for a series of articles by experts in the field, who have made key contributions to our understanding of the Maillard reaction in vivo.

Human plasminogen is highly susceptible to peroxynitrite inactivation

It has been shown that diabetic patients have up to three-fold increases in plasma nitrated tyrosine. We hypothesize that nitration of plasminogen could impair its catalytic properties and be a factor in diabetic thrombogenicity. To test this hypothesis, in this study we addressed the effects of the peroxynitrite donor 3-morpholinosydnonimine (SIN-1) on human streptokinase-induced plasmin activity. Given the link between glycation and oxidation we also explored whether peroxynitrite enhances the effect of fructose (1-5 mmol/l) and glucose (5-50 mmol/l) on plasminogen. We provide evidence that plasminogen, but not antithrombin III, is quickly inactivated by exogenously generated peroxynitrite (0-20 mmol/l SIN-1), in a time-and dose-dependent manner. The effect occurs even when the molar ratio of other plasma proteins and key antioxidants is respected. In our system, peroxynitrite did not enhance the effect of the sugars. Preincubation of the sugars with peroxynitrite also failed to produce any effect. This suggests that in conditions and times approaching the in vivo situation, plasminogen is more susceptible to peroxynitrite damage than to carbonyl damage. Plausibly, nitration of tyrosine should play a critical role in either conformational or functional changes. If proven in ulterior in vivo studies, this factor would provide another mechanism by which nitrosative stress participates in diabetic complications.

The polyamines spermine and spermidine protect proteins from structural and functional damage by AGE precursors: a new role for old molecules?

Due to the importance of glycation in the genesis of diabetic complications, an intense search for synthetic new antiglycation agents is ongoing. However, a somewhat neglected avenue is the search for endogenous compounds that may inhibit the process and be a source of protodrugs. Based on their ubiquity, their polycationic nature, their essential role in growth, their relatively high concentrations in tissues, and their high concentrations in sperm, we hypothesized that polyamines inhibit glycation and that might be one of their so far elusive functions. In this study we demonstrate a potent antiglycation effect of physiological concentrations of the polyamines spermine and spermidine. We employed two approaches: in the first, we monitored structural changes on histones and ubiquitin in which polyamines inhibit glycation-induced dimer and polymer formation. In the second we monitored functional impairment of catalytic activity of antithrombin III and plasminogen. Protection is afforded against glycation by hexoses, trioses and dicarbonyls AGE precursors and is comparable to those of aminoguanidine and carnosine.