Endothelium-dependent vasorelaxing activity of aqueous extracts of Ilex paraguariensis on mesenteric arterial bed of rats

Yerba Maté (Ilex paraguariensis) Metabolic, Satiety, and Mood State Effects at Rest and during Prolonged Exercise

Yerba Maté (YM), has become a popular herb ingested for enhancing metabolic health and weight-loss outcomes. No studies have tested the combined metabolic, satiety, and psychomotor effects of YM during exercise. We tested whether YM ingestion affects fatty acid oxidation (FAO), profile of mood state score (POMS), and subjective appetite scale (VAS), during prolonged moderate exercise. Twelve healthy active females were randomized to ingest either 2 g of YM or placebo (PLC) in a repeated-measures design. Participants rested for 120 min before performing a 30-min cycling exercise corresponding to individuals’ crossover point intensity (COP). FAO, determined using indirect calorimetry, was significantly higher during the 30-min exercise in YM vs. PLC (0.21 ± 0.07 vs. 0.17 ± 0.06 g/min, p < 0.05). VAS scores for hunger, prospective eating, and desire to eat were all reduced (p < 0.05). Whereas, POMS measures of focus, energy, and concentration were all increased (p < 0.05). There was no significant time-effect for any of the measured variables, nor was there any interaction effects between YM treatment and time. Combining YM intake with prolonged exercise at targeted ”fat-loss”’ intensities augments FAO and improves measures of satiety and mood state. Such positive combined metabolic, satiety, and psychomotor effects may provide an important role for designing future fat and weight-loss lifestyle interventions.

Vascular Responses to Extractable Fractions of Ilex paraguariensis in Rats Fed Standard and High-Cholesterol Diets

The authors investigated the vasorelaxant properties of the aqueous (Aq-EF) and acid n-butanolic (acn-BuOH) extractable fractions from Ilex paraguariensis leaves. Perfusion pressure was evaluated using isolated and perfused mesenteric arterial beds (MABs) from rats fed hypercholesterolemic and standard diets. Extract-induced vasorelaxation in the presence and absence of various inhibitors was examined following precontraction of the MABs with methoxamine (30 μM) solution. In hypercholesterolemic-diet rats, relaxation in intact MABs was significantly decreased with ac-n-BuOH-EF bolus (300, 600, 900 μg) in comparison to those in standard-diet rats. After the endothelium was stripped from the MABs, the vascular responses to ac-n-BuOH-EF and 900 μg bolus of Aq-EF were significantly changed. Treatment of the MABs with an inhibitor of nitric oxide synthase, NG -nitro-L-arginine methylester hydrochloride (L-NAME, 10 mM), did not change either ac-n-BuOH-EF- or Aq-EF-induced vasodilation except for the 900 g bolus of Aq-EF. The guanilate cyclase inhibitor methylene blue (100 μM) did not affect vasodilation for either fraction in the MABs from the hypercholesterolemic-diet rats. The chronic oral administration of I. paraguariensis extract in hypercholesterolemic-diet rats resulted in a significant reduction in serum levels of cholesterol and triglycerides. These results suggest that I. paraguariensis ac-n-BuOH-EF and Aq-EF induce vasodilation in standard-diet rats in a dose-dependent manner and that the hypercholesterolemic diet substantially reduced the effect of ac-n-BuOH-EF on precontracted MABs.

Topical menthol increases cutaneous blood flow

Menthol, the active ingredient in several topically applied analgesics, activates transient receptor potential melastatin 8 (TRPM8) receptors on sensory nerves and on the vasculature inducing a cooling sensation on the skin. Ilex paraguariensis is also a common ingredient in topical analgesics that has potential vasoactive properties and may alter the mechanisms of action of menthol. We sought to characterize the microvascular effects of topical menthol and ilex application and to determine the mechanism(s) through which these compounds may independently and combined alter cutaneous blood flow. We hypothesized that menthol would induce vasoconstriction and that ilex would not alter skin blood flow (SkBF). Three separate protocols were conducted to examine menthol and ilex-mediated changes in SkBF. In protocol 1, placebo, 4% menthol, 0.7% ilex, and combination menthol+ilex gels were applied separately to the skin and red cell flux was continuously measured utilizing laser speckle contrast imaging (LSCI). In protocol 2, seven concentrations of menthol gel (0.04%, 0.4%, 1%, 2%, 4%, 7%, 8%) were applied to the skin to model the dose-response curve. In protocol 3, placebo, menthol, ilex, and menthol+ilex gels were applied to skin under local thermal control (34°C) both with and without sensory nerve blockage (topical lidocaine 4%). Post-occlusive reactive hyperemia (PORH) and local heating (42°C) protocols were conducted to determine the relative contribution of endothelium derived hyperpolarizing factors (EDHFs)/sensory nerves and nitric oxide (NO), respectively. Red cell flux was normalized to mean arterial pressure expressed as cutaneous vascular conductance (CVC: flux·mmHg(-1)) in all protocols. Topical menthol application increased SkBF compared to placebo (3.41±0.33 vs 1.1±0.19CVC: p<0.001). During the dose-response, SkBF increased with increasing doses of menthol (main effect, p<0.05) with an ED50 of 1.0%. Similarly, SkBF was increased after menthol application during PORH (3.62±0.29 vs. 2.50±0.21flux·mmHg(-1); p<0.001), but not local heating (2.98±0.24 vs 2.86±0.32flux·mmHg(-1); p=0.44). Concurrent sensory nerve inhibition attenuated menthol-mediated vasodilation at thermoneutral baseline (1.29±0.19flux·mmHg(-1); p<0.001) and during PORH (2.79±0.28flux·mmHg(-1); p<0.001), but not during local heating (3.45±0.21flux·mmHg(-1); p=0.1). Topically applied menthol, but not ilex, dose-dependently increases blood flow in the cutaneous microvasculature. This increase in blood flow is mediated, in-part by sensory nerves and EDHFs.

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.

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.

Endothelium-dependent vascular relaxation induced by Globularia alypum extract is mediated by EDHF in perfused rat mesenteric arterial bed

The vasodilatory effect of Globularia alypum L. (GA) extract was evaluated in rat mesenteric arterial bed pre-contracted by continuous infusion of phenylephrine (2-4 ng/mL). Bolus injections of GA elicited dose-response vasodilation, which was abolished after endothelium removal. Addition of a nitric oxide synthase inhibitor, N(G)-nitro-l-arginine methyl ester (100 µmol/L), alone or in the presence of a cyclooxygenase inhibitor, indomethacin (10 µmol/L), did not significantly affect the vasodilation of the mesenteric arterial bed in response to GA extract. These results suggest that GA-induced vasodilation is endothelium dependent but nitric oxide and prostacyclin independent. In the presence of high K(+) (60 mmol/L), the GA vasodilatory effect was completely abolished, suggesting that the vasodilation effect is mediated by hyperpolarization of the vascular cells. Also, pre-treatment with atropine (a muscarinic receptors antagonist) antagonized the GA-induced vasodilation, suggesting that the vasodilatory effect is mainly mediated by the endothelium-derived hyperpolarizing factor through activation of endothelial muscarinic receptors.

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.

Consumption of mate tea (Ilex paraguariensis) decreases the oxidation of unsaturated fatty acids in mouse liver

Mate (Ilex paraguariensis) is rich in polyphenolic compounds, which are thought to contribute to the health benefits of tea. Mate tea was administered orally to mice at a dose of 0·5, 1·0 or 2·0 g/kg for 60 d, and changes both in serum lipid concentration and fatty acid composition of liver and kidney were examined. The effects of mate tea on serum and tissue lipid peroxidation were assessed by the evaluation of thiobarbituric acid-reactive substances (TBARS). In tea-consuming mice, both MUFA (18 : 1n-9) and PUFA (18 : 2n-6 and 20 : 4n-6) were increased (P < 0·05) in the liver lipid (approximately 90 and 60 %, respectively), whereas only MUFA (approximately 20 %) were increased in the kidney lipid. The most altered PUFA class wasn-6 PUFA, which increased by approximately 60–75 % (P < 0·05). This difference in the fatty acid profile in the liver is reflected in the increased PUFA:SFA ratio. Consistent with these results, mice fed with mate tea had much lower TBARS in the liver. No differences (P>0·05) were found in the levels of serum cholesterol, HDL-cholesterol and TAG under the conditions of the present study. These results suggest that treatment with mate tea was able to protect unsaturated fatty acids from oxidation and may have selective protective effects within the body, especially on the liver.

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.

Effects of two medicinal plants Psidium guajava L. (Myrtaceae) and Diospyros mespiliformis L. (Ebenaceae) leaf extracts on rat skeletal muscle cells in primary culture

Crude decoction, aqueous and ethanolic extracts of two medicinal plants (Psidium guajava and Diospyros mespiliformis), widely used in the central plateau of Burkina Faso to treat many diseases were evaluated for their antagonistic effects on caffeine induced calcium release from sarcoplasmic reticulum of rat skeletal muscle cells. These different extracts showed a decrease of caffeine induced calcium release in a dose dependent manner. Comparison of the results showed that Psidium guajava leaf extracts are more active than extracts of Diospyros mespiliformis and that crude decoctions show better inhibitory activity. The observed results could explain their use as antihypertensive and antidiarrhoeal agents in traditional medicine, by inhibiting intracellular calcium release.

Aqueous extract of Ilex paraguariensis attenuates the progression of atherosclerosis in cholesterol-fed rabbits

Ilex paraguariensis aqueous extract (mate) is an antioxidant-rich beverage widely consumed in South American countries. Here we questioned whether mate could reduce the progression of atherosclerosis in 1% cholesterol-fed rabbits. New Zealand White male rabbits (n = 32) were divided into four groups: control (C, n = 5), control-mate (CM, n = 5), hypercholesterolemic (HC, n = 11) and hypercholesterolemic-mate (HCM, n = 11). The daily water and mate extract consumption was approximately 400 ml. After 2 months of treatment, mate intake did not change the lipid profile or hepatic cholesterol content of control or hypercholesterolemic rabbits (p < 0.05). However, the atherosclerotic lesion area was considerably smaller in the hypercholesterolemic-mate group (HCM, 35.4% vs. HC, 60.1%; p < 0.05). In addition, the aortic cholesterol content was around half that of the HC group (HCM, 36.8 vs. HC, 73.9 microg/mg of protein, p < 0.05). In spite of this, the thiobarbituric acid-reactive substances (TBARS) in the atherosclerotic aorta, liver and serum, and the activity of the antioxidant enzymes in liver and aorta did not differ among groups (p > 0.05). The results showed that Ilex paraguariensis extract can inhibit the progression of atherosclerosis in cholesterol-fed rabbits, although it did not decrease the serum cholesterol or aortic TBARS and antioxidant enzymes.

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.

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.

Aqueous extract of Ilex paraguariensis decreases nucleotide hydrolysis in rat blood serum

Mate is a xanthine-containing beverage, which is prepared as an infusion of the dried and ground leaves of Ilex paraguariensis St. Hil. (Aquifoliacea). Previous reports have shown that Ilex paraguariensis has the highest levels of caffeine and theobromine when compared to other Ilex species. Furthermore, mate is able to interfere in the circulatory system, acting as a diuretic and hypotensive agent. Many processes of vascular injury result in the release of adenine nucleotides, which exert a variety of effects. Nucleoside 5' tri- and diphosphates may be hydrolyzed by members of the ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDase) family. The synchronic action of a NTPDase and a 5'-nucleotidase promotes the catabolism of ATP to adenosine, which is able to control the extracellular nucleotides/nucleosides ratio. The chronic ingestion of aqueous extract of Ilex paraguariensis by rats during 15 days significantly decreased ATP (55%), ADP (50%) and AMP (40%) hydrolysis in blood serum. These results suggest changes in the balance of purine levels induced by Ilex paraguariensis ingestion. Considering the potential effects of Ilex paraguariensis in the circulatory system, these results may be relevant since NTPDases are a novel drug target for the treatment of cardiovascular diseases.

Endothelium-dependent vasorelaxing activity of aqueous extracts of lyophilized seeds of Casimiroa edulis (AECe) on rat mesenteric arterial bed

The vasorelaxing activity of the aqueous extracts of Casimiroa edulis seeds F(AECe) on mesenteric arterial bed (MAB) of rats was studied. MAB precontracted with methoxamine was mounted on a tissue bath and exposed to plant extracts (bolus 50, 500, 2500 and 5000 microg). The bolus injections of AECe significantly inhibited, in a concentration-dependent manner, the maximal contractile response induced by methoxamine (30 microm) in MAB. After endothelium removal, the vascular ability of Casimiroa edulis aqueous extract was significantly changed. Treatment with an inhibitor of NO synthase (L-NOA, 10 microM) also modified the AECe effect. The guanilate cyclase inhibitor methylene blue (MB, 100 microM) inhibited the AECe-induced vasodilatation. These results suggest the involvement of NO of endothelial source (or related factors) in this vasodilator effect.

Fish Balistes capriscus skin extract-induced relaxation in mesenteric arterial bed of rat

The vasorelaxing activity of the aqueous extract of fish Balistes capriscus skin (AEBc) on mesenteric arterial bed (MAB) of rats was studied. The bolus injections of AEBc (bolus of 5.1, 10.2, 20.5, and 41.1mg) significantly inhibited, in a concentration-dependent manner, the maximal contractile response induced by methoxamine (30 microM) in MAB. The vasodilatation action of AEBc is not mediated through beta-adrenoceptors or cyclo-oxigenase, since it was not affected by propranolol (20 microM) or diclofenac sodium (3 microM). The vasodilator response induced by subsequent addition of AEBc Balistes capriscus in bolus was significantly reduced in water infusion for endothelium removal. Treatment with an inhibitor of NO synthase (L-NAME, 10 microM) decreased AEBc effect. The guanylate cyclase inhibitor methylene blue (MB, 100 microM) had no significant effect on AEBc-induced vasodilatation. These results suggest that the vasorelaxing effect of AEBc is mediated by endothelium-dependent (NO/EDRF) and endothelium-independent neurally induced vasorelaxation from nonadrenergic and noncholinergic nerves (NO).