Protective action of Ilex paraguariensis extract against free radical inactivation of paraoxonase-1 in high-density lipoprotein

Ilex paraguariensis A.St.-Hil. improves lipid metabolism in high-fat diet-fed obese rats and suppresses intracellular lipid accumulation in 3T3-L1 adipocytes via the AMPK-dependent and insulin signaling pathways

Background

Obesity is closely associated with several chronic diseases, and adipose tissue plays a major role in modulating energy metabolism.

Objective

This study aimed to determine whether Mate, derived from I. paraguariensis A.St.-Hil., ameliorates lipid metabolism in 3T3-L1 adipocytes and high-fat diet (HFD)-fed obese Sprague-Dawley (SD) rats.

Design

3T3-L1 adipocytes were cultured for 7 days, following which intracellular lipid accumulation and expression levels of lipid metabolism-related factors were examined. Dorsomorphin was used to investigate the potential pathways involved, particularly the adenosine monophosphate-activated protein kinase (AMPK)- dependent pathway. Mate was administered to rat HFD-fed obese SD models for 8 consecutive weeks. The expression of lipid metabolism-related factors in the organs and tissues collected from dissected SD rats was evaluated.

Results

Mate suppressed intracellular lipid accumulation in 3T3-L1 adipocytes, increased the protein and gene expression levels of AMPK, hormone sensitive lipase (HSL), calmodulin kinase kinase (CaMKK), liver kinase B1 (LKB1), protein kinase A (PKA), CCAAT/enhancer binding protein β (C/EBPβ), insulin receptor b (IRβ), and insulin receptor substrate 1 (IRS1) (Tyr465), and decreased those of sterol regulatory element binding protein 1C (Srebp1c), fatty acid synthase (FAS), peroxisome-activated receptor γ (PPARγ), and IRS1 (Ser1101). Furthermore, an AMPK inhibitor abolished the effects exerted by Mate on intracellular lipid accumulation and HSL and FAS expression levels. Mate treatment suppressed body weight gain and improved serum cholesterol levels in HFD-fed obese SD rats. Treatment with Mate increased the protein and gene expression levels of AMPK, PKA, Erk1/Erk2 (p44/p42), and uncoupling protein 1 and reduced those of mammalian target of rapamycin, S6 kinase, Srebp1c, ap2, FAS, Il6, Adiponectin, Leptin, and Fabp4 in rat HFD-fed obese SD models.

Discussion and conclusions

Mate suppressed intracellular lipid accumulation in 3T3-L1 adipocytes and improved lipid metabolism in the epididymal adipose tissue of HFD-fed obese SD rats via the activation of AMPK-dependent and insulin signaling pathways.

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.

Phytochemicals as Modulators of Paraoxonase-1 in Health and Diseases

Chronic diseases such as cardiovascular disease (CVD), atherosclerosis, chronic liver disease, and neurodegenerative diseases are major causes of mortality. These diseases have gained much attention due to their complications, and therefore novel approaches with fewer side effects are an important research topic. Free radicals and oxidative stress are involved in the molecular mechanisms of several diseases. Antioxidants can scavenge free radicals and mitigate their adverse effects. One of the most important antioxidant enzymes are paraoxonases (PONs). These enzymes perform a wide range of physiological activities ranging from drug metabolism to detoxification of neuroleptics. Paraoxonase-1 (PON1) is produced in the liver and then transferred to the bloodstream. It has been demonstrated that PON1 could have beneficial effects in numerous diseases such as atherosclerosis, CVD, diabetes mellitus, and neurodegenerative diseases by modulating relevant signalling pathways involved in inflammation and oxidative stress. These pathways include peroxisome proliferator-activated receptor gamma (PPAR-γ) and protein kinase B/nuclear factor kappa-light-chain-enhancer of activated B cells (AKT/NF-κB)-dependent signalling pathways. Increasing PON1 could potentially have protective effects and reduce the incidence of various diseases by modulating these signalling pathways. Several studies have reported that dietary factors are able to modulate PON1 expression and activity. This review aimed at summarizing the state of the art on the effects of dietary phytochemicals on PON1 enzyme activity and the relevant signalling pathways in different diseases.

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.

Yerba Mate-A Long but Current History

Bearing in mind the growing interest in Yerba Mate, a comprehensive study has been prepared containing the most important aspects and possibilities of its use. The introduction of the work contains the species characteristics of Yerba Mate, as well as information about the origin and places of cultivation. The next part focuses on the analysis of the composition, pointing to purine alkaloids, polyphenols, saponins, and minerals as groups of active compounds responsible for the clinical activity of Yerba Mate. The review of the results of preclinical and clinical studies indicates activity in relation to the stimulating effect, reducing weight by stimulating lipolysis, cardioprotective, anti-diabetic, and anti-inflammatory effects. The information about the action of Yerba Mate is supplemented by the characteristics of its potential toxicity in terms of PAHs content (in particular benzo[α]pyrene) and preparation as a determinant of increased irritation. The current data on the effects of Yerba Mate and the wide safety margin of its use position this raw material as a valuable component of functional food. The growing frequency of consuming Yerba Mate, conditioned by the availability resulting from the globalization of the market and the information provided about it's the pro-health effects, will position Yerba Mate's popularity among wider population groups.

Effect of yerba mate and green tea on paraoxonase and leptin levels in patients affected by overweight or obesity and dyslipidemia: a randomized clinical trial

Background

This study aimed to evaluate the effect of the intake of yerba mate (YM) and green tea (GT) on serum levels of leptin and paraoxonase-1 (PON-1), compared to control.

Methods

Controlled, randomized clinical trial (RCT) that evaluated 142 men and women affected by overweight or obesity aged 35–60 years, untreated dyslipidemia and no history of coronary artery disease. Participants were randomized to ingest 1000 mL GT, YM or apple tea (AT, control group) daily, during eight weeks. Serum PON-1 and leptin levels were analyzed by ELISA immunoassay at the beginning (baseline) and after eight weeks of intervention.

Results

The intake of 1 l of YM/day resulted in significant increase in serum levels of PON-1 (9.7%; p = 0.005). The consumption of GT induced no significant difference in the levels of PON-1 (p = 0.154) and leptin (p = 0.783). Intergroup analysis showed a significant difference (p = 0.036) in the variation of PON-1 levels in the YM group when compared to GT and AT groups. In addition, the increase in PON-1 levels in the YM group was significantly associated with increased HDL-c (p = 0.004).

Conclusions

The intake of yerba mate increased the antioxidant capacity by increasing serum levels of PON-1 and was positively associated with increased HDL-c, stressing the protective role of this beverage against atherosclerotic diseases. GT intake had no significant effect on serum levels of PON-1 and leptin.

Trial registration

This study is registered with ClinicalTrials.gov under protocol number NCT00933647.

Enzyme-assisted extraction of polyphenols from green yerba mate

Abstract The enzyme-assisted extraction of bioactive compounds from plants has been studied as an alternative green technology and the carbohydrases have been candidates to improve the extraction process of numerous such compounds from plants. Polyphenols are secondary plant metabolites, generally involved in the defense against different types of stress and yerba mate (Ilex paraguariensis A. St.-Hil., Aquifoliaceae) is a natural source of these antioxidant compounds. The aim of this work was to evaluate the enzyme-assisted extraction of polyphenols from green yerba mate employing response surface methodology (RSM), in order to determine the best extraction conditions. The independent variables were temperature (33.2 to 66.8 °C), enzyme concentration (0 to 336 FGBU/100g), reaction time (19 to 221 minutes) and pH (2.82 to 6.18). The use of carbohydrases increased the extraction of polyphenols from about 38.67% to 52.08%. The present results showed that all the independent variables were significant at the linear level and that temperature and pH were not significant at the quadratic level. The interactions of temperature and pH; enzyme and reaction time; and enzyme and pH were significant. The regression model presented a determination coefficient (R2) close to 0.85 and a fitted value close to 0.45. Considering the results of this study and their industrial viability, the best conditions for the extraction of polyphenols from green yerba mate are a temperature of 50.0 °C, enzyme concentration of 168 FGB/100 g, reaction time of 120 minutes and pH value of 4.50. This study was the first RSM-based report of the optimization of the enzyme-assisted extraction of total phenolic compounds from green yerba mate.

Mate tea reduces high fat diet-induced liver and metabolic disorders in mice

High-fat diet (HFD)-induced obesity is a worldwide health problem and can cause lipid accumulation in the liver. We evaluated the hepatoprotective effect of mate tea treatment in mice submitted to an HFD. C57BL/6 mice were fed an HFD for 13 weeks with and without mate tea. A separate group of mice was treated with fenofibrate as a positive control (a regular drug for lipid disorders). Histological analyses, glucose tolerance tests (GTT), and quantification of mediators related to lipid peroxidation, oxidative stress and blood biomarkers for lipid profile were performed. The weight of animals and major organs related to hepatic steatosis was determined, and proinflammatory cytokines and the participation of the Nrf2 pathway and adiponectin were evaluated. Mate tea prevented the accumulation of lipid droplets in hepatocytes as well as weight gain in animals submitted to the HFD. Mate tea treatment also prevented increases in the liver weight, heart weight and amount of visceral and subcutaneous white adipose tissue. Mate tea was able to prevent the deregulation of glucose uptake, as evaluated by GTT, and improved the indicators of oxidative stress, such as nitrite levels, catalase activity, and oxidative damage, as evaluated by protein carbonylation and the MDA levels. Mate tea had an anti-inflammatory effect, preventing the increase of IL-1β and KC and upregulating the expression of Nrf2. Mate tea prevented insulin increase and HDL cholesterol decrease but did not affect total cholesterol or triglycerides levels. Treatment also prevented adiponectin increase. Mate tea may be a good resource to reduce hepatic steatosis in the future since it has anti-diabetic, anti-inflammatory and antioxidant effects, which prevent the accumulation of fat in the liver.

Chemistry, pharmacology and new trends in traditional functional and medicinal beverages

Functional and medicinal beverages consumption plays an important role in human health, considering that metabolites, with a wide range of pharmacological effects, are inserted in the human diet. Nowadays, the most consumed beverages are obtained from Camellia sinensis leaves and coffee grain processing, and contain different classes of polyphenols and phenolic acids in their phytochemical composition. Besides C. sinensis and coffee, numerous plants have been receiving attention due to their phytochemical composition and pharmacological effects, such as yerba mate, hibiscus, chamomile, lemongrass, fennel and mentha. Furthermore, atomized or lyophilized medicinal plant extracts can be employed in many beverage formulations and the consumption of these products is an excellent delivery means for nutrients and bioactive compounds, such as: minerals, vitamins, terpenes, antioxidants, saponins, alkaloids and polysaccharides. Innovation in food processing in order to insert functional and medicinal beverages in the human diet poses a challenge for the coming years. The technological development of new processing forms and use of plants with bioactive metabolites could be an important tool in relation to this proposal. In this context, this review has aimed to summarize and analyze pharmacological, phytochemistry and technological aspects of species with classical ethnobotanical and traditional use.

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.

Effect of yerba mate (Ilex paraguariensis) extract on the metabolism of diabetic rats

The relationship between metabolic disturbances and clinical events related to diabetes is well known. Yerba mate has presented a potential use as preventive and therapeutic agent on diabetes. The aim of this study was to evaluate the effect of yerba mate on different tissues of diabetic rats, focusing on energetic metabolism. Diabetes was induced by streptozotocin, followed by daily yerba mate treatment. After 30 days, the animals were euthanized to evaluate metabolic parameters on liver, adipose tissue, muscle and serum. The results showed mate treatment promoted a decrease in retroperitoneal adipose tissue in healthy animals. Muscle weight returned to control levels in diabetic rats treated with mate. There was improvement on serum glucose, creatinine, urea and total protein levels associated with mate treatment. Muscle parameters, such as glucose uptake and carbon dioxide production, were improved by mate treatment to control levels. The results evidenced the beneficial actions mate can have on metabolic disturbances of diabetes.

The Search for Dietary Supplements to Elevate or Activate Circulating Paraoxonases

Low levels of paraoxonase 1 (PON1) have been associated with the development of several pathological conditions, whereas high levels have been shown to be anti-atherosclerotic in mouse models. These findings suggest that PON1 could be a good surrogate biomarker. The other members of the family, namely PON2 and PON3, the role of which has been much less studied, deserve more attention. This paper provides a systematic review of current evidence concerning dietary supplements in that regard. Preliminary studies indicate that the response to dietary supplements may have a nutrigenetic aspect that will need to be considered in large population studies or in clinical trials. A wide range of plant preparations have been found to have a positive action, with pomegranate and some of its components being the best characterized and Aronia melanocarpa one of the most active. Flavonoids are found in the composition of all active extracts, with catechins and genistein being the most promising agents for increasing PON1 activity. However, some caveats regarding the dose, length of treatment, bioavailability, and stability of these compounds in formulations still need to be addressed. Once these issues have been resolved, these compounds could be included as nutraceuticals and functional foods capable of increasing PON1 activity, thereby helping with the long-term prevention of atherosclerosis and other chronic ailments.

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).

Distribution of Major Chlorogenic Acids and Related Compounds in Brazilian Green and Toasted Ilex paraguariensis (Maté) Leaves

Ilex paraguariensis (maté) is one of the best sources of chlorogenic acids (CGA) in nature. When leaves are toasted, some isomers are partly transformed into 1,5-γ-quinolactones (CGL). Both CGA and CGL are important contributors to the brew's flavor and are thought to contribute to human health. In this study, we quantified 9 CGA, 2 CGL, and caffeic acid in 20 samples of dried green and toasted maté that are commercially available in Brazil. Total CGA content in green maté varied from 8.7 to 13.2 g/100 g, dry weight (dw). Caffeic acid content varied from 10.8 to 13.5 mg/100 g dw, respectively. Content in toasted maté varied from 1.5 to 4.6 g/100 g and from 1.5 to 7.2 mg/100 g dw, respectively. Overall, caffeoylquinic acid isomers (CQA) were the most abundant CGA in both green and toasted maté, followed by dicaffeoylquinic acids (diCQA) and feruloylquinic acids (FQA). These classes accounted for 58.5%, 40.0%, and 1.5% of CGA, respectively, in green maté and 76.3%, 20.7%, and 3.0%, respectively, in toasted maté. Average contents of 3-caffeoylquinolactone (3-CQL) and 4-caffeoylquinolactone (4-CQL) in commercial toasted samples were 101.5 mg/100 g and 61.8 mg/100 g dw, respectively. These results show that, despite overall losses during the toasting process, CGA concentrations are still substantial in toasted leaves, compared to other food sources of CGA and phenolic compounds in general. In addition to evaluating commercial samples, investigation of changes in CGA profile and formation of 1,5-γ-quinolactones was performed in experimental maté toasting.

Desenvolvimento de chocolate branco com extrato de erva-mate

Resumo O chocolate é um produto apreciado mundialmente e as tendências do setor apontam para a busca de inovações e a procura por produtos mais saudáveis. Da mesma forma, muitos estudos têm demonstrado os benefícios nutricionais da erva-mate (Ilex paraguariensis), dentre eles a atividade antioxidante atribuída ao seu alto teor de compostos fenólicos, tornando-a uma matéria-prima potencial para o desenvolvimento de novos produtos. O presente trabalho tem por objetivo a aplicação de extrato de erva-mate no desenvolvimento de chocolate branco, a fim de elaborar um produto inovador e que atenda às necessidades de saudabilidade dos consumidores. Foram elaboradas formulações com 1%, 3% e 5% de extrato de erva-mate, determinadas por delineamento composto central 22 para o extrato de erva-mate e vanilina. Todas as amostras apresentaram padrão microbiológico em conformidade com o exigido pela legislação brasileira e foram analisadas sensorialmente, a fim de verificar quais eram as mais aceitas pelos consumidores. As formulações com 1% e 3% de extrato de erva-mate foram as mais aceitas para todos os atributos analisados. Os teores de compostos fenólicos variaram de 137,61 a 198,42 mg EAG/100 g e a atividade antioxidante de 83,39 a 179,73 EC50 (mg/mg). Os resultados mostram que o produto desenvolvido apresentou boa aceitabilidade e a aplicação de extrato de erva-mate acrescentou ao chocolate branco compostos fenólicos com ação antioxidante.

Paraoxonase 1 and HDL maturation

Understanding the kinetics and function of paraoxonase 1 (PON1) is becoming an important issue in atherosclerosis. Low PON1 activity has been consistently linked with an increased risk of major cardiovascular events in the setting of secondary prevention of coronary artery disease. Recent studies have shown that there is a specific interaction of myeloperoxidase (MPO)-apoAI-PON1 on HDL surface that seems to be germane to atherogenesis. MPO specifically inhibits PON1 and PON1 mitigates MPO effects. Surprisingly, very little is known about the routes by which PON1 gets integrated into HDL or its fate during HDL remodeling in the intravascular space. We have developed a method that assesses PON1 activity in the individual HDL subclasses with the aid of which we have shown that PON1 is present across the HDL particle range and preferentially in HDL3, confirming data from ultracentrifugation (UC) studies. Upon HDL maturation ex vivo PON1 is activated and it shows a flux to both smaller and larger HDL particles as well as to VLDL and sdLDL. At the same time apoE, AI and AII are shifted across particle sizes. PON1 activation and flux across HDL particles are blocked by CETP and LCAT inhibitors. In a group of particles with such a complex biology as HDL, knowledge of the interaction between apo-lipoproteins, lipids and enzymes is key for an increased understanding of the yet multiple unknown features of its function. Solving the HDL paradox will necessitate the development of techniques to explore HDL function that are practical and well adapted to clinical studies and eventually become useful in patient monitoring. The confluence of proteomic, functional studies, HDL subclasses, PON1 assays and zymogram will yield data to draw a more elaborate and comprehensive picture of the function of HDL. It must be noted that all these studies are static and conducted in the fasting state. The crucial phase will be achieved when human kinetic studies (both in the fasting and post-prandial states) on HDL-PON1, apoA-I and lipid fate in the circulation are carried out.

Optimization of Phenolics and Flavonoids Extraction Conditions and Antioxidant Activity of Roasted Yerba-Mate Leaves (Ilex paraguariensis A. St.-Hil., Aquifoliaceae) using Response Surface Methodology

This study focused on maximizing the extraction of total phenolics and flavonoids as well as the antioxidant activity measured by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay from roasted yerba mate (Ilex paraguariensis) as a function of time (5, 7.5 and 10 min) and temperature of extraction (60, 75 and 90°C). The data were subjected to Response Surface Methodology and the results showed that polynomial equations were significant, did not present lack of fit, and presented adjusted determination coefficients above 98%, proving their suitability for prediction purposes. Using the desirability function, the optimum operating conditions to obtain a higher extraction of antioxidants was found to be 10 min of extraction at 90°C, and the tea prepared under these experimental conditions presented 427.74 mg of gallic acid equivalents per liter and 80.02% of inhibition of the DPPH radical. The flavonoid content was highly correlated (r = 0.9046, p < 0.001) to the antioxidant capacity.

Beneficial effects of Yerba Mate tea (Ilex paraguariensis) on hyperlipidemia in high-fat-fed hamsters

Yerba Mate tea (Mate), an infusion made from the leaves of the tree Ilex paraguariensis, is a widely consumed beverage in South America. Mate has previously been shown to have hypolipidemic effects. However, its mechanism of action is not well understood. This study was conducted to determine the effect of Mate on hyperlipidemia induced in hamsters by a high-fat diet, as well as its mechanism of action. Fifty male hamsters were randomly assigned to normal control, high-fat control, and high-fat with Mate tea aqueous extract (1%, 2% or 4% w/v) groups. We evaluated the effects of Mate aqueous extract on body weight, serum lipids, antioxidant enzyme activity, lipoprotein metabolism enzyme activity, and gene expression involved in lipid metabolism in hyperlipidemic hamsters. Mate aqueous extract significantly decreased body-weight gain and lowered serum lipid levels in the hyperlipidemic hamster model. Meanwhile, Mate treatment increased antioxidant enzyme activity, improved lipoprotein lipase (LPL) and hepatic lipase (HL) activities in serum and liver, upregulated mRNA expression of peroxisome proliferator-activated receptor α and low density lipoprotein receptor, and downregulated mRNA expression of sterol regulatory element-binding protein 1c and acetyl CoA carboxylase in the liver. The results indicate that Mate tea ameliorates hyperlipidemia partly by reducing lipid peroxidation, improving endothelial function and LPL and HL activities, and modulating the expression levels of genes involved in lipid oxidation and lipogenesis.

Yerba mate (Ilex paraguariensis) enhances the gene modulation and activity of paraoxonase-2: in vitro and in vivo studies

OBJECTIVE

Paraoxonase-2 (PON-2) is an intracellular antioxidant enzyme that can be modulated by polyphenols. The aim of this study was to verify whether yerba mate (Ilex paraguariensis), a plant species rich in phenolic compounds, modulates gene expression and the activity of PON-2 in macrophages in vitro and in monocytes from peripheral blood and monocyte-derived macrophages obtained after the ingestion of green or roasted yerba mate infusions by healthy subjects.

METHODS

THP-1 macrophages were incubated with increasing amounts of yerba mate extracts or chlorogenic and caffeic acids (1-10 μmol/L). The in vivo effects of yerba mate or water (control) intakes were evaluated acutely (2 h after ingestion) and in the short term (after daily ingestion for 7 d) in 20 healthy women.

RESULTS

In general, there was no difference between the two kinds of yerba mate studied. Yerba mate extracts or chlorogenic acid at 1 and 3 μmol/L increased PON-2 relative gene expression in THP-1 macrophages (P < 0.05), whereas higher concentrations (5 and 10 μmol/L) increased the activity only. Caffeic acid induced PON-2 activity only. The acute ingestion of yerba mate infusions increased relative gene expression and PON-2 activity in monocytes (P < 0.05), whereas the consumption of yerba mate for 7 d increased PON-2 relative gene expression (P < 0.05) and had a tendency to increase PON-2 activity in monocytes and monocyte-derived macrophages.

CONCLUSION

It is suggested that green or roasted yerba mate modulates positively the mRNA relative expression and activity of the PON-2 enzyme in monocytes and macrophages, which may prevent cellular oxidative stress.

Association of mate tea (Ilex paraguariensis) intake and dietary intervention and effects on oxidative stress biomarkers of dyslipidemic subjects

OBJECTIVE

To evaluate the effect of long-term ingestion of mate tea, with or without dietary intervention, on the markers of oxidative stress in dyslipidemic individuals.

METHODS

Seventy-four dyslipidemic volunteers participated in this randomized clinical trial. Subjects were divided into three treatment groups: mate tea (MT), dietary intervention (DI), and mate tea with dietary intervention (MD). Biochemical and dietary variables were assessed at the beginning of the study (baseline) and after 20, 40, 60, and 90 d of treatment. Participants in the MT and MD groups consumed 1 L/d of mate tea. Those in the DI and MD groups were instructed to increase their intake of fruit, legumes and vegetables and decrease their consumption of foods rich in cholesterol and saturated and trans-fatty acids. Biomarkers of oxidative stress such as antioxidant capacity of serum (ferric reducing antioxidant potential assay), uric acid, reduced glutathione, paraoxonase-1 enzyme, lipid hydroperoxide (LOOH), and protein carbonyl were analyzed.

RESULTS

Participants in the DI group showed a significant decrease in total fat and saturated fatty acid intakes. Those in the DI and MD groups presented a significant increase in vitamin C consumption. For all groups, there was a significant increase in ferric reducing antioxidant potential and reduced glutathione concentrations but no significant changes in LOOH, protein carbonyl, and paraoxonase-1 values. The reduced glutathione concentration was positively correlated with the consumption of monounsaturated fatty acids, fiber, and vitamin C, whereas levels of LOOH were inversely correlated with intakes of vitamin C and fiber. In addition, LOOH correlated positively with low-density lipoprotein cholesterol and inversely with high-density lipoprotein cholesterol, which had a positive association with paraoxonase-1.

CONCLUSION

The ingestion of mate tea independently of the dietary intervention increased plasma and blood antioxidant protection in patients with dyslipidemia.

Recent advances on Ilex paraguariensis research: minireview

Ilex paraguariensis dried and minced leaves are made into a brewed tea, prepared in a sui generis manner by large populations in South America, having evolved from a tea drunk by the Guarani ethnic group to a beverage that has a social and almost ritualistic role in some South American modern societies. It is used both as a source of caffeine, in lieu or in parallel with tea and coffee, but also as a therapeutic agent for its alleged pharmacological properties. Although with some exceptions, research on biomedical properties of this herb has had a late start and strongly lags behind the impressive amount of literature on green tea and coffee. However, in the past 15 years, there was a several-fold increase in the literature studying Ilex paraguariensis properties showing effects such as antioxidant properties in chemical models and ex vivo lipoprotein studies, vaso-dilating and lipid reduction properties, antimutagenic effects, controversial association with oropharyngeal cancer, anti-glycation effects and weight reduction properties. Lately, promising results from human intervention studies have surfaced and the literature offers several developments on this area. The aim of this review is to provide a concise summary of the research published in the past three years, with an emphasis on translational studies, inflammation and lipid metabolism. Ilex paraguariensis reduces LDL-cholesterol levels in humans with Ilex paraguariensis dyslipoproteinemia and the effect is synergic with that of statins. Plasma antioxidant capacity as well as expression of antioxidant enzymes is positively modulated by intervention with Ilex paraguariensis in human cohorts. A review on the evidence implicating Ilex paraguariensis heavy consumption with some neoplasias show data that are inconclusive but indicate that contamination with alkylating agents during the drying process of the leaves should be avoided. On the other hand, several new studies confirm the antimutagenic effects of Ilex paraguariensis in different models, from DNA double breaks in cell culture models to mice studies. Novel interesting work has emerged showing significant effect on weight reduction both in mice and in rat models. Some mechanisms involved are inhibition of pancreatic lipase, activation of AMPK and uncoupling of electron transport. Intervention studies in animals have provided strong evidence of anti-inflammatory effects of Ilex paraguariensis, notably protecting cigarette-induced lung inflammation acting on macrophage migration and inactivating matrix-metalloproteinase. Research on the effects of Ilex paraguariensis in health and disease has confirmed its antioxidant, anti-inflammatory, antimutagenic and lipid-lowering activities. Although we are still waiting for the double-blind, randomized prospective clinical trial, the evidence seems to provide support for beneficial effects of mate drinking on chronic diseases with inflammatory component and lipid metabolism disorders.

Antioxidant Activity of Polyphenols from Green and Toasted Mate Tea

The production and distribution of toasted mate tea in Brazil has increased, which has resulted in its greater consumption. Mate tea is obtained by roasting non-fermented erva-mate in order to produce toasted erva-mate or toasted mate tea. However, although the product is much appreciated, studies of its chemical composition and the concentration of polyphenols, particularly flavonols present in toasted mate tea, are few and often controversial. This paper elucidates some misunderstandings involving the nomenclature of erva-mate and toasted mate, and mainly provides an overview of the composition of polyphenols and antioxidant capacity of toasted mate tea and its raw material, erva-mate, in comparison with other teas, the compositions of which were found in the literature.

Maté tea inhibits in vitro pancreatic lipase activity and has hypolipidemic effect on high-fat diet-induced obese mice

The inhibitory effects of maté tea (MT), a beverage produced with leaves from Ilex paraguariensis, in vitro lipase activity and on obesity in obese mice models were examined. For the in vitro experiment, porcine and human pancreatic lipase (PL) activities were determined by measuring the rate of release of oleic acid from hydrolysis of olive oil emulsified with taurocholate, phospholipids, gum arabic, or polyvinyl alcohol. For the in vivo experiments, animals were fed with a standard diet (SD, n = 10) or high-fat diet (HFD, n = 30) for 16 weeks. After the first 8 weeks on the HFD, the animals were treated with 1 and 2 g/kg of body weight of MT. The time course of the body weight and obesity-related biochemical parameters were evaluated. The results showed that MT inhibited both porcine and human PL (half-maximal inhibitory concentration = 1.5 mg MT/ml) and induced a strong inhibition of the porcine lipase activity in the hydrolysis of substrate emulsified with taurocholate + phosphatidylcholine (PC) (83 +/- 3.8%) or PC alone (62 +/- 4.3%). MT suppressed the increases in body weight (P < 0.05) and decreased the serum triglycerides and low-density lipoprotein (LDL)-cholesterol concentrations at both doses (from 190.3 +/- 5.7 to 135.0 +/- 8.9 mg/dl, from 189.1 +/- 7.3 to 129.3 +/- 17.6 mg/dl; P < 0.05, respectively) after they had been increased by the HFD. The liver lipid content was also decreased by the diet containing MT (from 132.6 +/- 3.9 to 95.6 +/- 6.1 mg/g of tissue; P < 0.05). These results suggest that MT could be a potentially therapeutic alternative in the treatment of obesity caused by a HFD.

Effects of maté tea intake on ex vivo LDL peroxidation induced by three different pathways

Yerba maté (Ilex paraguariensis) is a native South America plant widely consumed as different beverages. Yerba maté leaves contains high concentrations of polyphenols that are responsible for its high in vitro and in vivo antioxidant activity. The in vivo antioxidant properties vis a vis LDL particles has not yet been studied for maté tea, the roasted yerba maté product. The aim of this study was to evaluate the antioxidant activity of maté tea ingestion ex vivo on human LDL. Fasting peripheral venous blood samples of healthy women were taken in three different times: before drinking the tea, one hour later and after one week (7 days) of daily consumption of maté tea. The isolated LDL was oxidized by three different pathways [copper (CuSO₄), lipoxygenase and peroxynitrite (SIN-1)]. Conjugated dienes and structural modifications on LDL were evaluated. Ingestion of maté tea increased LDL resistance towards ex vivo copper oxidation, but did not alter the peroxidation pattern when SIN-1 or lipoxygenase were used as oxidants

Yerba Maté (Ilex paraguariensis) aqueous extract decreases intestinal SGLT1 gene expression but does not affect other biochemical parameters in alloxan-diabetic Wistar rats

Yerba maté (Ilex paraguariensis) is rich in polyphenols, especially chlorogenic acids. Evidence suggests that dietary polyphenols could play a role in glucose absorption and metabolism. The aim of this study was to evaluate the antidiabetic properties of yerba maté extract in alloxan-induced diabetic Wistar rats. Animals (n = 41) were divided in four groups: nondiabetic control (NDC, n = 10), nondiabetic yerba maté (NDY, n = 10), diabetic control (DC, n = 11), and diabetic yerba maté (DY, n = 10). The intervention consisted in the administration of yerba maté extract in a 1 g extract/kg body weight dose for 28 days; controls received saline solution only. There were no significant differences in serum glucose, insulin, and hepatic glucose-6-phosphatase activity between the groups that ingested yerba maté extract (NDY and DY) and the controls (NDC and DC). However, the intestinal SGLT1 gene expression was significantly lower in animals that received yerba maté both in upper (p = 0.007) and middle (p < 0.001) small intestine. These results indicate that bioactive compounds present in yerba maté might be capable of interfering in glucose absorption, by decreasing SGLT1 expression.