Anticonvulsant, neuroprotective and behavioral effects of organic and conventional yerba mate (Ilex paraguariensis St. Hil.) on pentylenetetrazol-induced seizures in Wistar rats

Phytotherapeutic options for the treatment of epilepsy: pharmacology, targets, and mechanism of action

Epilepsy is one of the most common, severe, chronic, potentially life-shortening neurological disorders, characterized by a persisting predisposition to generate seizures. It affects more than 60 million individuals globally, which is one of the major burdens in seizure-related mortality, comorbidities, disabilities, and cost. Different treatment options have been used for the management of epilepsy. More than 30 drugs have been approved by the US FDA against epilepsy. However, one-quarter of epileptic individuals still show resistance to the current medications. About 90% of individuals in low and middle-income countries do not have access to the current medication. In these countries, plant extracts have been used to treat various diseases, including epilepsy. These medicinal plants have high therapeutic value and contain valuable phytochemicals with diverse biomedical applications. Epilepsy is a multifactorial disease, and therefore, multitarget approaches such as plant extracts or extracted phytochemicals are needed, which can target multiple pathways. Numerous plant extracts and phytochemicals have been shown to treat epilepsy in various animal models by targeting various receptors, enzymes, and metabolic pathways. These extracts and phytochemicals could be used for the treatment of epilepsy in humans in the future; however, further research is needed to study the exact mechanism of action, toxicity, and dosage to reduce their side effects. In this narrative review, we comprehensively summarized the extracts of various plant species and purified phytochemicals isolated from plants, their targets and mechanism of action, and dosage used in various animal models against epilepsy.

Evaluation of the Effects of Instant Cascara Beverage on the Brain-Gut Axis of Healthy Male and Female Rats

Instant cascara (IC) is a sustainable beverage obtained from dried coffee cherry pulp, rich in nutrients and bioactive compounds. The present research aimed to determine the effects of IC on general health and brain-gut axis parameters of healthy female and male rats. Wistar rats were exposed to IC (10 mg/mL) in their drinking water for 3 weeks. Body weight and solid and liquid intakes were monitored as indicators of food safety. Gastrointestinal transit was radiographically evaluated one day (acute) and 3 weeks (chronic) after the start of IC exposure. Locomotor activity, anxiety, and anhedonia of the animals after 3 weeks of treatment was also studied. Overall, compared to water-exposed animals, IC significantly increased food intake in males (p < 0.0001) and liquid intake in females (p < 0.05) without changes in body weight in either case. IC did not significantly modify gastrointestinal motility parameters after its acute or repeated intake and did not cause any significant behavioral alterations in males or females (p > 0.05). In conclusion, repeated intake of IC at the studied concentration did not negatively affect brain-gut axis functions of healthy male and female rats. Anxiety behavior, diarrhea, constipation, abnormal weight modifications, or other typical effects of toxicity were not observed in animals treated with the new powdered beverage, suggesting its food safety under the studied conditions.

Physiological effects of yerba maté (Ilex paraguariensis): a systematic review

CONTEXT

Clinical studies have found an association between yerba maté intake and beneficial physiological effects. Nevertheless, no systematic reviews have been conducted to shed light on the data supporting this association.

OBJECTIVE

The present systematic review aimed to investigate the physiological effects of yerba maté.

DATA SOURCES

Searches were performed in 6 databases (Embase, LILACS, Scopus, PubMed, SciELO, Web of Science) and 3 grey literature databases (OpenGrey, ProQuest, Google Scholar). Relevant publications were identified, and the reference lists of included studies were searched manually for randomized clinical trials, nonrandomized clinical trials, and observational studies investigating the physiological effects of yerba maté.

DATA EXTRACTION

Risk of bias was assessed using the Cochrane risk of bias tool for randomized trials and the Cochrane ROBINS-I (Risk Of Bias In Nonrandomized Studies of Interventions) tool. Joanna Briggs Institute critical appraisal tools were used for cross-sectional, case series, cohort, and case-control studies. The overall certainty of the evidence was estimated using the GRADE (Grading of Recommendations, Assessment, Development and Evaluations) working group summary of findings table.

DATA ANALYSIS

Of 1096 studies identified, 32 were included. Studies showed consistent effects of yerba maté intake on metabolism improvement and antioxidant and anti-inflammatory activities in different populations. Benefits for body weight and composition, exercise performance, mood, and appetite, in addition cardio- and neuroprotective effects, were also observed. Risk of bias was categorized as high in 22 studies, moderate in 9 studies, and low in 1 study. The certainty of evidence ranged from moderate to very low.

CONCLUSION

The available literature indicates that yerba maté can be used within a balanced and healthy diet for prevention and adjuvant treatment of chronic diseases.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD42020200196.

Therapeutic Potential of Quercetin and its Derivatives in Epilepsy: Evidence from Preclinical Studies

Quercetin is a polyphenolic bioactive compound highly enriched in dietary fruits, vegetables, nuts, and berries. Quercetin and its derivatives like rutin and hyperoside are known for their beneficial effects in various neurological conditions including epilepsy. The clinical studies of quercetin and its derivatives in relation to epilepsy are limited. This review provides the evidence of most recent knowledge of anticonvulsant properties of quercetin and its derivatives on preclinical studies. Additionally, the studies demonstrating antiseizure potential of various plants extracts enriched with quercetin and its derivatives has been included in this review. Herein, we have also discussed neuroprotective effect of these bioactive compound and presented underlying mechanisms responsible for anticonvulsant properties in brief. Finally, limitations of quercetin and its derivatives as antiseizure compounds as well as possible strategies to enhance efficacy have also been discussed.

Hibiscus, Rooibos, and Yerba Mate for Healthy Aging: A Review on the Attenuation of In Vitro and In Vivo Markers Related to Oxidative Stress, Glycoxidation, and Neurodegeneration

The world is currently undergoing a demographic change towards an increasing number of elderly citizens. Aging is characterized by a temporal decline in physiological capacity, and oxidative stress is a hallmark of aging and age-related disorders. Such an oxidative state is linked to a decrease in the effective mechanisms of cellular repair, the incidence of post-translational protein glycation, mitochondrial dysfunction, and neurodegeneration, just to name some of the markers contributing to the establishment of age-related reduction-oxidation, or redox, imbalance. Currently, there are no prescribed therapies to control oxidative stress; however, there are strategies to elevate antioxidant defenses and overcome related health challenges based on the adoption of nutritional therapies. It is well known that herbal teas such, as hibiscus, rooibos, and yerba mate, are important sources of antioxidants, able to prevent some oxidation-related stresses. These plants produce several bioactive metabolites, have a pleasant taste, and a long-lasting history as safe foods. This paper reviews the literature on hibiscus, rooibos, and yerba mate teas in the context of nutritional strategies for the attenuation of oxidative stress-related glycoxidation and neurodegeneration, and, here, Alzheimer’s Disease is approached as an example. The focus is given to mechanisms of glycation inhibition, as well as neuroprotective in vitro effects, and, in animal studies, to frame interest in these plants as nutraceutical agents related to current health concerns.

Toxicity evaluation of traditional and organic yerba mate (Ilex paraguariensis A. St.-Hil.) extracts

Yerba mate (Ilex paraguariensis A. St.-Hil.) is an important source of biologically active compounds with pharmacological potential. The aim of this study was to examine the toxicity of different extracts obtained from either traditional or organic cultivated yerba mate in vitro and in vivo. Aqueous, ethanolic and methanolic extracts were obtained from commercial samples of yerba mate and total phenolic content was determined employing Folin-Ciocalteau reagent. The aqueous extracts presented higher content of total phenols, compared to ethanolic and methanolic extracts, and also demonstrated lower cytotoxicity, which is the basis for testing were carried out only using aqueous extracts. The main phenolic acids found in traditional aqueous (TA) extract were chlorogenic, gallic and protocatechuic acids. Gallic and hydroxybenzoic acids were detected in aqueous cultivated organic (OA) extract. Pretreatment with OA extract (100 µg/ml, 1 hr) was cytoprotective against rotenone-induced toxicity (1 µM). For in vivo toxicity assay, zebrafish embryos were exposed to OA or TA extracts (10-160 µg/ml) at 4 hr post fertilization. TA extract decreased embryos survival in a concentration-dependent manner, reduced the hatching rate at 40 µg/ml, increased edema frequency at 80 µg/ml and altered body curvature at 120 µg/ml. Further, TA extract produced locomotor disorders at concentrations equal to or greater than 10 µg/ml. In contrast, OA extract exhibited no apparent toxic effect on organogenesis and behavior up to 100 µg/ml. In summary, the OA cultivated extract showed the lowest cytotoxicity in vitro, enhanced reduction in rotenone-induced toxicity, and produced less toxicity in zebrafish embryos compared to the TA extract.

Parameters of Oxidative Stress and Behavior in Animals Treated with Dexametasone and Submitted to Pentylenetetrazol Kindling

Background and Purpose

Oxidative stress (OS) is defined as an excessive production of reactive oxygen species that cannot be neutralized by the action of antioxidants, but also as an alteration of the cellular redox balance. The relationship between OS and epilepsy is not yet fully understood. The objective of this study was to evaluate the effect of dexamethasone on OS levels and memory in the kindling model induced by pentylenetetrazole.

Methods

The animals were divided in six groups: control group that received no treatment, vehicle group treated with vehicle, diazepam group, and groups treated with dexamethasone (1, 2 and 4 mg/kg). Treated animals received pentylenetetrazole in alternated days for 15 days. Inhibitory avoidance test was conducted in 2 hours and OS was evaluated after animal sacrifice.

Results

Regarding the treatment with dexamethasone, there was no significant difference when compared to the control groups in relation to the inhibitory avoidance test. On OS levels, there was a decrease in catalase activity levels in the hippocampus and an increase in thiobarbituric acid reactive substances and glutathione peroxidase levels in the hippocampus.

Conclusions

The anticonvulsant effect of dexametasone remains uncertain. Immunological mechanisms, with the release of cytokines and inflammatory mediators, seem to be the key to this process. The mechanisms that generate OS are probably related to the anticonvulsant effects found.

Chimarrão, terere and mate-tea in legitimate technology modes of preparation and consume: A comparative study of chemical composition, antioxidant, anti-inflammatory and anti-anxiety properties of the mostly consumed beverages of Ilex paraguariensis St. Hil

ETHNOPHARMACOLOGICAL RELEVANCE

Ilex paraguariensis St. Hil. (Aquifoliaceae) is a medicinal plant widely used by South American populations for centuries and is popularly attributed to stimulating and detoxifying properties. Nowadays, their consume traditionally occurs through three different beverages: chimarrão, terere and mate-tea.

AIM OF THE STUDY

Although its composition and properties are well studied, literature lacks work comparing the potential of their extracts obtained by a legitimate preparation mode of their popular beverages. Therefore, the purpose of this research is to investigate changes in chemical composition, antioxidant activity, anti-inflammatory efficacy and anxiolytic effect from lyophilized aqueous extracts obtained simulating the legitimate popular preparation mode of chimarrão, terere and mate-tea.

MATERIALS AND METHODS

In this work, were investigated differences related to preparation technology and dry material used through chemical composition analysis, with the lyophilized aqueous extracts obtained simulating the chimarrão, terere and mate-tea preparation. The chemical composition analysis comprises the total soluble phenolics content, chemical profiles by HPLC-ESI-MS/MS, and quantitative component detection by HPLC-UV/DAD. Moreover, evaluations of comparative antioxidant activity of the extracts (DPPH and ORAC_FL assays), anti-inflammatory efficacy and anxiolytic effect were performed in vivo.

RESULTS

Our results showed that chimarrão extracts presented a richer composition in terms of phenolic compounds and purine alkaloids, and better antioxidant activity when compared to the other extracts. In pleurisy test, all products showed anti-inflammatory properties in the dose of 60 mg/kg. In the anxiolytic evaluation, although all extracts presented some effect, chimarrão and terere were better than mate-tea in general. No sign of toxicity was observed.

CONCLUSIONS

Our findings support that the beverage made as chimarrão has the best composition and the most promising properties overall.

The modulator action of thiamine against pentylenetetrazole-induced seizures, apoptosis, nitric oxide, and oxidative stress in rats and SH-SY5Y neuronal cell line

Accumulating evidences indicate that thiamine plays a vital role in the nervous system. However, questions exist as to how it causes epilepsy, neuronal damage, and antiepileptic mechanisms. The study looked at how the thiamine supplement impacted pentylenetetrazole (PTZ)-induced seizures in rats and pentylenetetrazole-induced neurotoxicity in the SH-SY5Y cell line. We used twenty-four male rats and they were randomly divided into 4 groups as control, saline (1 mL/kg/day serum physiologic) + PTZ, thiamine (50 mg/kg/day) + PTZ, and thiamine (50 mg/kg/day) for 10 days. PTZ (45 mg/kg) was given to activate the seizure on day 10. Memory efficiency was measured by using passive avoidance. The brain levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), caspase-3, nitric oxide (NO), and cyclic guanosine monophosphate (cGMP) were analyzed by using ELISA kits. SH-SY5Y cells were treated with/without thiamine for 1 h, followed by PTZ (30 μm) at a medium level to trigger neurotoxicity. Cell viability, total antioxidant status, total oxidant status, and apoptosis were assayed in the SH-SY5Y cells. Thiamine delayed the initiation of epileptic seizures and increased memory damage. In addition, 8-OHdG, caspase-3, NO, and cGMP levels were significantly reduced in the brain and prevented pentylenetetrazole-induced neurotoxicity, apoptosis, enhanced antioxidant, and reduced oxidant in SH-SY5Y cells. Thiamine dramatically altered seizures, memory loss, oxidative stress, and apoptosis. Thiamine has a preventative effect on PTZ-induced seizures in rats and PTZ-induced neurotoxicity in SH-SY5Y neuroblastoma cells. It could prevent oxidative stress and signaling of NO/cGMP. Thiamine supplement could be used as an additional therapeutic agent in epilepsy.

A Case-Control Study of the Effects of Chimarrão (Ilex paraguariensis) and Coffee on Parkinson's Disease

Introduction: Coffee has been inversely associated with Parkinson's disease (PD) in many studies, and caffeine is the leading candidate to mediate this effect. Mate (Ilex paraguariensis, IP), a caffeinated beverage rich in antioxidants consumed in South America, was also inversely associated with PD in one study from Argentina. Other varieties of IP infusion, such as chimarrão, were never studied in PD. Chimarrão is a common caffeinated beverage consumed in Brazil made with the leaves and stems of IP.

Methods: A case–control study was conducted to evaluate the relationship between chimarrão ingestion and PD in southern Brazil. All subjects answered a questionnaire about the frequency of chimarrão and coffee intake. A multiple regression analysis adjusted for age and sex was performed to assess the association between PD and chimarrão consumption.

Results: We included 200 PD patients and 200 healthy controls. High consumption of chimarrão was inversely associated with PD (OR = 0.44, 95% CI = 0.24–0.81, P = 0.008). High consumption of coffee was also inversely associated with PD, as expected. Chimarrão remained associated when adjusted for coffee consumption, smoking history, and age (OR 0.46, 95% CI = 0.25–0.86, P = 0.014). These two exposures showed an additive effect.

Conclusion:Chimarrão consumption was inversely associated with PD, even after adjusting for coffee intake, suggesting a possible protective role. IP's effect can be mediated by caffeine and through its antioxidant components. Chimarrão has a lower concentration of caffeine compared with coffee and has numerous substances with antioxidative effects that may be important to PD protection. Further studies are needed to test this hypothesis.

The role of nitric oxide in anticonvulsant effects of lycopene supplementation on pentylenetetrazole-induced epileptic seizures in rats

Recent studies have shown that natural antioxidant compounds have positive effects on the nervous system. Lycopene, the red pigment in tomatoes, is one of the potent natural antioxidants, and is used as supplementation because of its well-known health benefits. However, its effect on epileptic seizures and underlying mechanisms are still unclear. In this study, it was aimed to investigate the effect of lycopene on pentylenetetrazole-induced epileptic seizures in rats and to elucidate the nitric oxide pathway in this effect. In this study, thirty male Wistar albino rats were used. Animals were divided into five groups (n = 6 for each group) as control, saline (1 mL/kg/day serum physiologic), positive control (2 mg/kg/day diazepam), and lycopene (5 and 10 mg/kg/day) for ten days. Pentylenetetrazole (45 mg/kg) was given to induce a seizure in the tenth day except for the control. Passive avoidance test was carried out to evaluate memory function. Inducible nitric oxide synthase (iNOS), neuronal nitric oxide synthase (nNOS), and nitric oxide (NO) levels were measured in the cortex and hippocampal brain regions using the ELISA kits. Lycopene supplementation prolonged epileptic seizure onset times and reduced seizure stages. Besides, lycopene supplementation improved memory impairment after seizures. Moreover, lycopene significantly reduced the level of iNOS, nNOS, and NO in the brain. Lycopene supplementation significantly alleviated seizures and memory impairment. Its anticonvulsive effect could be associated with the nitric oxide pathway. Lycopene supplementation could be useful as a supportive therapeutic agent in epileptic patients.

The Effects of Proton Pump Inhibitors (Pantoprazole) on Pentylenetetrazole-Induced Epileptic Seizures in Rats and Neurotoxicity in the SH-SY5Y Human Neuroblastoma Cell Line

Recent studies have shown that proton pump inhibitors have positive effects on the nervous system. However, its effect on epileptic seizure and neuronal damage are still unclear. In this study, it was aimed to investigate the effect of pantoprazole on pentylenetetrazole-induced epileptic seizures in rats and neurotoxicity in the SH-SY5Y cell line. Animals were divided into three groups: control, saline (1 mL/kg serum physiologic), and pantoprazole (10 mg/kg). Pentylenetetrazole (45 mg/kg) was given to induce a seizure and a passive avoidance test trial was carried out to evaluate memory function. 8-hydroxy-2'-deoxyguanosine (8-OHdG), caspase-3, and brain-derived neurotrophic factor (BDNF) levels were measured in the brain by commercial kits. SH-SY5Y cells were treated with saline or pantoprazole for one hour, and then pentylenetetrazole (30 µm) was added to the medium to induce neurotoxicity. After 24 h, cell viability, total antioxidant, total oxidant status, and apoptosis were measured in SH-SY5Y cells. It was found that pantoprazole treatment postponed epileptic seizure onset, protected memory, reduced 8-OHdG, caspase-3, and also increased BDNF in the brain. In addition, it blocked pentylenetetrazole toxicity, apoptosis, increased antioxidant, and decreased oxidant status in SH-SY5Y cells. Pantoprazole significantly improved seizure, oxidative stress, and apoptosis. Thus, pantoprazole could be used as a supportive therapeutic agent in epilepsy.

Effect of the Yerba mate (Ilex paraguariensis) brewing method on the content of selected elements and antioxidant potential of infusions

Yerba mate is a source of biologically active substances. The aim was to determine whether the place of origin of Yerba and the brewing method have any influence on the levels of Ca, Mg and Fe and antioxidant activity of infusions. Samples were steeped in cold water (25°C) and hot water (three consecutive infusions with 85°C water). Infusions had a high antioxidant activity and high Mg level. The levels of elements and the antioxidant activity were influenced by the brewing method. There were no significant differences in the examined parameters depending on the country of origin. The results on the levels of elements and the antioxidant activity indicate that the most efficient brewing method was infusion in hot water. The highest levels of elements were found in first infusions, with the highest antioxidant activity in the third infusions.

Garlic passion fruit (Passiflora tenuifila Killip): Assessment of eventual acute toxicity, anxiolytic, sedative, and anticonvulsant effects using in vivo assays

Several Passiflora species are known for their sedative and anxiolytic properties. However, the functional properties of Passiflora tenuifila Killip are still unexplored. The objective of this work was to evaluate the phenolic composition and acute toxicity, anxiolytic, sedative, and anticonvulsant effects using in vivo assays. The whole fruit (peel, pulp, and seed) was lyophilized and used for all assays. LC-MS showed 19 phenolic compounds, tentatively identified as flavonoids and phenolic acids. Acute treatment with single doses of up to 2000 mg kg^-1 in Wistar rats showed no signs of mortality or toxicity over 14 days. The assay of functional effects was performed with Swiss mice, four groups, received by gavage, doses of P. tenuifila (200 or 400 mg kg^-1 body weight), water, and diazepam (as negative and positive control), and behavior tests were performed after 60 min of the treatments. The animals treated with P. tenuifila fruit showed a significant decrease in locomotor activity, indicating a sedative and anxiolytic activity. No significant changes were observed in the rotarod apparatus, suggesting that the P. tenuifila fruit did not cause muscle relaxation. The 400 mg kg^-1 dose of P. tenuifila exerted a protective effect against pentylenetetrazole-induced seizures, decreasing the severity and not causing the death of the animals. In conclusion, P. tenuifila showed no acute toxicity and had a promising effect as an anxiolytic agent, hypnotic-sedative and anticonvulsant, which could be related to its composition of flavonoids and phenolic acids.

Ilex paraguariensis extract provides increased resistance against oxidative stress and protection against Amyloid beta-induced toxicity compared to caffeine in Caenorhabditis elegans

Ilex paraguariensis is a plant from South America, used to prepare a tea-like beverage rich in caffeine and polyphenols with antioxidant proprieties. Caffeine consumption is associated with a lower risk of age-associated neuropathologies, besides several extracts that have antioxidant proprieties are known to be neuroprotective, and oxidative stress strongly correlates with Aβ-toxicity. This study aims to investigate the neuroprotective effects of the Ilex paraguariensis hydroalcoholic extract (IPHE) and to evaluate if caffeine agent present in IPHE exerts neuroprotective effects in an amyloid beta-peptide (Aβ)-induced toxicity in Caenorhabditis elegans. The wild-type and CL2006 worms were treated with IPHE (2 and 4 mg/mL) or caffeine (200 and 400 μM) since larval stage 1 (L1) until they achieved the required age for each assay. IPHE and caffeine increased the lifespan and appeared to act directly by reactive oxygen species (ROS) scavenger in both wild-type and CL2006 worms, also conferred resistance against oxidative stress in wild-type animals. Furthermore, both treatments delayed Aβ-induced paralysis and decreased AChE activity in CL2006. The protective effect of IPHE against Aβ-induced paralysis was found to be dependent on heat shock factor hsf-1 and FOXO-family transcription factor daf-16, which are respectively involved in aging-related processes and chaperone synthesis, while that of caffeine was dependent only on daf-16. Mechanistically, IPHE and caffeine decreased the levels of Aβ mRNA in the CL2006 worms; however, only IPHE induced expression of the heat shock chaperonin hsp-16.2, involved in protein homeostasis. The results were overall better when treated with IPHE than with caffeine.

Improvement of phenolic compound bioaccessibility from yerba mate (Ilex paraguariensis) extracts after biosorption on Saccharomyces cerevisiae

Great efforts have been made to increase the bioaccessibility of bioactive compounds from plant sources. This can be achieved by the innovative and effective method of biosorption of these compounds in Saccharomyces cerevisiae obtained from the industrial fermentative process (waste yeast). In this context, this research evaluated if chemical modifications of depleted yeast can improve the capacity to biosorb the phenolic compounds and if through in vitro digestion tests, this approach can increase bioaccessibility of the secondary metabolites from yerba mate. The results showed that the chemical modification of the yeast promoted an increase in the biosorption efficiency of the bioactive compounds. Mass spectrometry peaks for the phenolic compounds reduced after biosorption as observed for the caffeic and dicaffeoylquinic acids and for kaempferol and rutin. In addition, a 10% reduction of caffeine was verified after biosorption, quantified by mass spectrometry chromatography. This showing that the compounds were retained in the cells, which was also observed by an increase of cell turgidity with scanning electron microscopy (SEM). Mid-infrared spectroscopy showed that the major bands related to the components of the compounds increased proportionally after biosorption. Furthermore, an increase of bioaccessibility of the yerba mate bioactive compounds adsorbed in S. cerevisiae was verified when compared with the crude extract.

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.

Neurotoxic Agent-Induced Injury in Neurodegenerative Disease Model: Focus on Involvement of Glutamate Receptors

Glutamate receptors play a crucial role in the central nervous system and are implicated in different brain disorders. They play a significant role in the pathogenesis of neurodegenerative diseases (NDDs) such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. Although many studies on NDDs have been conducted, their exact pathophysiological characteristics are still not fully understood. In in vivo and in vitro models of neurotoxic-induced NDDs, neurotoxic agents are used to induce several neuronal injuries for the purpose of correlating them with the pathological characteristics of NDDs. Moreover, therapeutic drugs might be discovered based on the studies employing these models. In NDD models, different neurotoxic agents, namely, kainic acid, domoic acid, glutamate, β-N-Methylamino-L-alanine, amyloid beta, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, 1-methyl-4-phenylpyridinium, rotenone, 3-Nitropropionic acid and methamphetamine can potently impair both ionotropic and metabotropic glutamate receptors, leading to the progression of toxicity. Many other neurotoxic agents mainly affect the functions of ionotropic glutamate receptors. We discuss particular neurotoxic agents that can act upon glutamate receptors so as to effectively mimic NDDs. The correlation of neurotoxic agent-induced disease characteristics with glutamate receptors would aid the discovery and development of therapeutic drugs for NDDs.

[Acute effect of yerba mate (Ilex paraguariensis) consumption on heart rhythm in patients referred for Holter study]

INTRODUCTION

The consumption of yerba mate (YM) (Ilex paraguariensis) is common in South America and is now used all over the world. It contains many bioactive substances that can be beneficial. There is also the opinion that it may have harmful effects on heart rhythm, but no studies have been found on this.

OBJECTIVE

The aim of this study was to evaluate the acute effect of YM on heart rhythm in patients referred for a Holter study.

METHOD

A before and after pseudo-experimental clinical study was conducted by performing a Holter on 50 habitual users of YM, and another one after 24 without YM consumption. The use of other products that could interfere was also controlled.

RESULTS

The mean age of the subjects was 55±15 years, and 52% were women. At least one vascular risk factor was found in 78%, with 44% structural heart disease, and 90% taking cardiovascular medication. The heart rate (HR) with and without YM was similar. Only the minimum hourly HR was lower when taking YM (61±10 vs. 63±9, P=.021). There was no significant difference in the incidence of sustained or non-sustained arrhythmias, or in ventricular extrasystoles. The total number of supra-ventricular premature beats was higher without YM (952±3,538 vs. 1,294±5,201, P=.014) and also the maximum hourly (86±302 vs. 107±360, P=.032). There was no difference in HR variability.

CONCLUSIONS

In cardiology patients, usual users of YM, habitual consumption was not associated with significant changes in HR or an increase in the incidence of arrhythmias. There was less ectopic supraventricular activity.

Anticonvulsant evaluation of novel non-imidazole histamine H3R antagonists in different convulsion models in rats

Novel non-imidazole histamine H3 receptor (H3R) antagonists (2-8) were developed and assessed for in-vitro antagonist binding affinities at the human histamine H1-H4R. These novel H3R antagonists (2-8) were examined in-vivo for anticonvulsant effects in three different convulsion models in male adult rats. Compound 6 significantly and dose-dependently exhibited decreased duration of tonic hind limb extension (THLE) in the maximal electroshock (MES)- and fully protected animals against pentylenetetrazole (PTZ)-induced convulsion, following acute systemic administration (5, 10, and 20 mg/kg, i.p.). Contrary, all compounds 2-8 showed moderate protection in the strychnine (STR)-induced convulsion model following acute pretreatment (10 mg/kg, i.p.). Moreover, the acute systemic administration of H3R antagonist 6 (10 mg/kg, i.p.) significantly prolonged latency time for MES convulsions. Furthermore, the anticonvulsant effect observed with compound 6 in MES-model was entirely abrogated when rats were co-injected with the brain penetrant H1R antagonist pyrilamine (PYR) but not the brain penetrant H2R antagonist zolantidine (ZOL). However, PYR and ZOL failed to abolish the full protection provided by the H3R antagonist 6 in PTZ- and STR-models. No mutagenic or antiproliferative effects or potential metabolic interactions were shown for compound 6 when assessing its antiproliferative activities and metabolic profiling applying in-vitro methods. These findings demonstrate the potential of non-imidazole H3R antagonists as novel antiepileptic drugs (AEDs) either for single use or in addition to currently available epilepsy medications.

Compounds from Ilex paraguariensis extracts have antioxidant effects in the brains of rats subjected to chronic immobilization stress

Immobilization induces oxidative damage to the brain. Ilex paraguariensis extracts (Mate) and their major natural compound, chlorogenic acid (CGA), exert protective effects against reactive oxygen species formation. Here, the effects of Mate and CGA on oxidative damage induced by chronic immobilization stress (CIS) in the cortex, hippocampus, and striatum were investigated. For CIS, animals were immobilized for 6 h every day for 21 consecutive days. Rats received Mate or CGA by intragastric gavage 30 min before every restraint session. Endpoints of oxidative stress (levels of lipid peroxidation, protein carbonylation, and reduced (GSH) and oxidized (GSSG) forms of glutathione) were evaluated following CIS. While CIS increased oxidized lipid and carbonyl levels in all brain regions, CGA (and Mate to a lesser extent) attenuated lipid and protein oxidation as compared with control groups. GSH/GSSG balance showed a tendency to increase in all regions in response to stress and antioxidants. Taken together, our results support a protective role of dietary antioxidants against the neuronal consequences of stress.

Phenylalanine derivatives with modulating effects on human α1-glycine receptors and anticonvulsant activity in strychnine-induced seizure model in male adult rats

The critical role of α1-glycine receptor (α1-GLYRs) in pathological conditions such as epilepsy is well known. In the present study, structure-activity relations for a series of phenylalanine derivatives carrying selected hydrogen bond acceptors were investigated on the functional properties of human α1-GLYR expressed in Xenopus oocytes. The results indicate that one particular substitution position appeared to be of special importance for control of ligand activity. Among tested ligands (1-8), the biphenyl derivative (2) provided the most promising antagonistic effect on α1-GLYRs, while its phenylbenzyl analogue (5) exhibited the highest potentiation effect. Moreover, ligand 5 with most promising potentiating effect showed in-vivo moderate protection when tested in strychnine (STR)-induced seizure model in male adult rats, whereas ligand 2 with highest antagonistic effect failed to provide appreciable anti(pro)convulsant effect. Furthermore, ligands 2 and 5 with the most promising effects on human α1-GLYRs were examined for their toxicity and potential neuroprotective effect against neurotoxin 6-hydroxydopamine (6-OHDA). The results show that ligands 2 and 5 possessed neither significant antiproliferative effects, nor necrotic and mitochondrial toxicity (up to concentration of 50μM). Moreover, ligand 2 showed weak neuroprotective effect at the 50μM against 100μM toxic dose of 6-OHDA. Our results indicate that modulatory effects of ligands 2 and 5 on human α1-GLYRs as well as on STR-induced convulsion can provide further insights for the design of therapeutic agents in treatment of epilepsy and other pathological conditions requiring enhanced activity of inhibitory glycine receptors.

Non-imidazole-based histamine H3 receptor antagonists with anticonvulsant activity in different seizure models in male adult rats

A series of twelve novel non-imidazole-based ligands (3–14) was developed and evaluated for its in vitro binding properties at the human histamine H3 receptor (hH3R). The novel ligands were investigated for their in vivo protective effects in different seizure models in male adult rats. Among the H3R ligands (3–14) tested, ligand 14 showed significant and dose-dependent reduction in the duration of tonic hind limb extension in maximal electroshock (MES)-induced seizure model subsequent to acute systemic administration (5, 10, and 20 mg/kg, intraperitoneally), whereas ligands 4, 6, and 7 without appreciable protection in MES model were most promising in pentylenetetrazole (PTZ) model. Moreover, the protective effect observed for ligand 14 in MES model was lower than that observed for the reference drug phenytoin and was entirely abrogated when rats were co-administered with the brain-penetrant H1R antagonist pyrilamine (PYR) but not the brain-penetrant H2R antagonist zolantidine (ZOL), demonstrating that histaminergic neurotransmission by activation of postsynaptically located H1Rs seems to be involved in the protective action. On the contrary, PYR and ZOL failed to abrogate the full protection provided by 4 in PTZ model and the moderate protective effect by 14 in strychnine (STR) model. Moreover, the experimental and in silico estimation of properties such as metabolism was performed for five selected test compounds. Also, lipophilicity using planar reversed-phase thin-layer chromatography method was included for better understanding of the molecular properties of the tested compounds. Additionally, the absorption, distribution, metabolism, and elimination and toxicity parameters were evaluated for the most promising compounds 2, 4, 6, 7, and 14 utilizing in vitro methods. These interesting results highlight the potential of H3R ligands as new antiepileptic drugs or as adjuvants to available epilepsy medications.

Anticonvulsant effects of isomeric nonimidazole histamine H3 receptor antagonists

Phenytoin (PHT), valproic acid, and modern antiepileptic drugs (AEDs), eg, remacemide, loreclezole, and safinamide, are only effective within a maximum of 70%–80% of epileptic patients, and in many cases the clinical use of AEDs is restricted by their side effects. Therefore, a continuous need remains to discover innovative chemical entities for the development of active and safer AEDs. Ligands targeting central histamine H₃ receptors (H₃Rs) for epilepsy might be a promising therapeutic approach. To determine the potential of H₃Rs ligands as new AEDs, we recently reported that no anticonvulsant effects were observed for the (S)-2-(4-(3-(piperidin-1-yl)propoxy)benzylamino)propanamide (1). In continuation of our research, we asked whether anticonvulsant differences in activities will be observed for its R-enantiomer, namely, (R)-2-(4-(3-(piperidin-1-yl)propoxy)benzylamino)propaneamide (2) and analogs thereof, in maximum electroshock (MES)-, pentylenetetrazole (PTZ)-, and strychnine (STR)-induced convulsion models in rats having PHT and valproic acid (VPA) as reference AEDs. Unlike the S-enantiomer (1), the results show that animals pretreated intraperitoneally (ip) with the R-enantiomer 2 (10 mg/kg) were moderately protected in MES and STR induced models, whereas proconvulsant effect was observed for the same ligand in PTZ-induced convulsion models. However, animals pretreated with intraperitoneal doses of 5, 10, or 15 mg/kg of structurally bulkier (R)-enantiomer (3), in which 3-piperidinopropan-1-ol in ligand 2 was replaced by (4-(3-(piperidin-1-yl)propoxy)phenyl)methanol, and its (S)-enantiomer (4) significantly and in a dose-dependent manner reduced convulsions or exhibited full protection in MES and PTZ convulsions model, respectively. Interestingly, the protective effects observed for the (R)-enantiomer (3) in MES model were significantly greater than those of the standard H₃R inverse agonist/antagonist pitolisant, comparable with those observed for PHT, and reversed when rats were pretreated with the selective H₃R agonist R-(α)-methyl-histamine. Comparisons of the observed antagonistic in vitro affinities among the ligands 1–6 revealed profound stereoselectivity at human H₃Rs with varying preferences for this receptor subtype. Moreover, the in vivo anticonvulsant effects observed in this study for ligands 1–6 showed stereoselectivity in different convulsion models in male adult rats.

Urtica dioica modulates hippocampal insulin signaling and recognition memory deficit in streptozotocin induced diabetic mice

Diabetes mellitus has been associated with functional abnormalities in the hippocampus and performance of cognitive function. Urtica dioica (UD) has been used in the treatment of diabetes. In our previous report we observed that UD extract attenuate diabetes mediated associative and spatial memory dysfunction. The present study aimed to evaluate the effect of UD extract on mouse model of diabetes-induced recognition memory deficit and explore the possible mechanism behind it. Streptozotocin (STZ) (50 mg/kg, i.p. consecutively for 5 days) was used to induce diabetes followed by UD extract (50 mg/kg, oral) or rosiglitazone (ROSI) (5 mg/kg, oral) administration for 8 weeks. STZ induced diabetic mice showed significant decrease in hippocampal insulin signaling and translocation of glucose transporter type 4 (GLUT4) to neuronal membrane resulting in cognitive dysfunction and hypolocomotion. UD treatment effectively improved hippocampal insulin signaling, glucose tolerance and recognition memory performance in diabetic mice, which was comparable to ROSI. Further, diabetes mediated oxidative stress and inflammation was reversed by chronic UD or ROSI administration. UD leaves extract acts via insulin signaling pathway and might prove to be effective for the diabetes mediated central nervous system complications.

Dietary total antioxidant capacity is associated with plasmatic antioxidant capacity, nutrient intake and lipid and DNA damage in healthy women

Dietary total antioxidant capacity (DTAC) seems to be associated with reducing risk of diseases. However, data about the influence of the DTAC on oxidative stress parameters are scarce. The aim of this study was to estimate the DTAC and its influence on plasma total antioxidant capacity (PTAC), and damage to lipids, proteins and DNA in healthy women. It was found a positive correlation between DTAC and PTAC in young and healthy subjects, where presumably the endogenous defenses are fully functional. DTAC and PTAC were positively correlated with the intake of known antioxidants, including vitamin C and polyphenols. The DTAC exhibited a negative correlation with lipid oxidative damage, while PTAC showed a negative correlation with DNA damage. This data contributes to better understanding of the recommended dietary antioxidant intake for promoting health.

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.

Anticonvulsant and procognitive properties of the non-imidazole histamine H3 receptor antagonist DL77 in male adult rats

It has become clear that histamine H3 receptors (H3Rs) are implicated in modulating epilepsy and memory in laboratory animals. The new non-imidazole H3R antagonist DL77 has excellent selectivity profile and shows high in-vivo potency as well as in-vitro antagonist affinity with ED50 values of 2.1 ± 0.2 mg/kg and 8.4 ± 1.3 [nM], respectively. In the present study, the anticonvulsant effects of DL77 on maximal electroshock (MES)-, pentylenetetrazole (PTZ)-, and strychnine (STR)-induced seizure models were investigated. Moreover, the procognitive properties of DL77 were tested on acquisition, consolidation and retrieval processes in a one-trial inhibitory avoidance task in male Wistar rats. The results indicate that DL77 (5, 10, and 15 mg/kg, i.p.) significantly and dose-dependently reduced MES-induced seizure duration, whereas no protection was observed in PTZ- or STR-induced seizures. Importantly, the protective action observed for DL77 in MES-induced seizure was comparable to that of the reference antiepileptic drug (AED) phenytoin (PHT), and was also reversed when rats were pretreated with the CNS penetrant pyrilamine (PYR) (10 mg/kg, i.p.), or with the selective H3R agonist R-(α)-methyl-histamine (RAMH) (10 mg/kg, i.p.). Furthermore, the procognitive studies indicate that acute pre-training systemic administration of DL77 (2.5 mg/kg, i.p.) facilitated acquisition, whereas pre-testing acute administration of DL77 (5 and 10 mg/kg, i.p.) improved retrieval. Interestingly, the procognitive effect of DL77 on retrieval was completely abrogated when rats were pretreated with the centrally-acting H2R antagonist zolantidine (ZOL) but not the centrally acting H1R antagonist PYR, indicating that histaminergic pathways through activation of H2Rs appear to be participating in neuronal circuits involved in retrieval processes. Taken together, our results show that DL77 demonstrates anticonvulsant properties in the MES-induced seizure model and improves cognitive performance through actions on different memory stages. Therefore, H3Rs may have implications for the treatment of degenerative disorders associated with impaired memory function and may represent a novel therapeutic pharmacological target to tackle cognitive problems associated with the chronic use of antiepileptic drugs. This article is part of the Special Issue entitled 'Histamine Receptors'.

Anxiolytic-like, stimulant and neuroprotective effects of Ilex paraguariensis extracts in mice

Yerba-mate (Ilex paraguariensis St. Hil.) is the most used beverage in Latin America with approximately 426 thousand of tons consumed per year. Considering the broad use of this plant, we aimed to investigate the anxiety-like and stimulant activity of both the hydroethanolic (HE) and aqueous (AE) extracts from leaves of I. paraguariensis. Swiss mice were treated with I. paraguariensis HE or AE chronically or acutely, respectively, followed by evaluation in the elevated plus-maze (EPM; anxiety-like paradigm), open field (OF; locomotor activity) or the step-down avoidance task (memory assessment). Following behavioral protocols the brains were collected for evaluation of acetylcholinesterase (AChE) activity ex vivo. Chronic treatment with HE induced an anxiolytic-like effect and increased motor activity besides augmented AChE activity. Additionally, acute treatment with AE prevented the scopolamine-induced memory deficit in the step-down avoidance task. Overall, our results indicate the importance of the I. paraguariensis-induced CNS effects, since it is a widely used nutraceutical. We have reported anxiolytic, stimulant and neuroprotective effects for this plant species. These effects are potentially modulated by the cholinergic system as well as by caffeine.

Seizure-induced oxidative stress in temporal lobe epilepsy

An insult to the brain (such as the first seizure) causes excitotoxicity, neuroinflammation, and production of reactive oxygen/nitrogen species (ROS/RNS). ROS and RNS produced during status epilepticus (SE) overwhelm the mitochondrial natural antioxidant defense mechanism. This leads to mitochondrial dysfunction and damage to the mitochondrial DNA. This in turn affects synthesis of various enzyme complexes that are involved in electron transport chain. Resultant effects that occur during epileptogenesis include lipid peroxidation, reactive gliosis, hippocampal neurodegeneration, reorganization of neural networks, and hypersynchronicity. These factors predispose the brain to spontaneous recurrent seizures (SRS), which ultimately establish into temporal lobe epilepsy (TLE). This review discusses some of these issues. Though antiepileptic drugs (AEDs) are beneficial to control/suppress seizures, their long term usage has been shown to increase ROS/RNS in animal models and human patients. In established TLE, ROS/RNS are shown to be harmful as they can increase the susceptibility to SRS. Further, in this paper, we review briefly the data from animal models and human TLE patients on the adverse effects of antiepileptic medications and the plausible ameliorating effects of antioxidants as an adjunct therapy.

Deuterium-depleted water has stimulating effects on long-term memory in rats

Deuterium-depleted water (DDW) is a water which has a 6-7-fold less concentration of the naturally occurring deuterium (20-25ppm vs. 150ppm). While administrated for a longer period, it may reduce the concentration of deuterium throughout the body, thus activating cellular mechanisms which are depending on protons (channels, pumps, enzyme proteins). The aim of the present work was to study, for the first time in our knowledge, the possible influence of deuterium-depleted water (DDW) chronic administration in normal Wistar rats, as compared to a control group which received distilled water, on spatial working memory and the locomotor activity (as studied through Y-maze) or both short-term and long-term spatial memory (assed in radial 8 arms-maze task). Our results presented here showed no significant modifications in terms of spatial working memory (assessed through spontaneous alternation percentage) and locomotor activity (expressed through the number of arm entries) in Y-maze, as a result of DDW ingestion. Also, no significant differences between the DDW and control group were found in terms of the number of working memory errors in the eight-arm radial maze, as a parameter of short-term memory. Still, we observed a significant decrease for the number of reference memory errors in the DDW rats. In this way, we could speculate that the administration of DDW may generate an improvement of the reference memory, as an index of long-term memory. Thus, we can reach the conclusion that the change between the deuterium/hydrogen balance may have important consequences for the mechanisms that govern long-term memory, as showed here especially in the behavioral parameters from the eight-arm radial maze task.

Antioxidant Effect of Lippia alba (Miller) N. E. Brown

Lippia alba is a shrub found in all regions of Brazil and other countries in South and Central America. L. alba exhibits variability among its different accessions, showing differences in morphology and in the composition of its essential oil. This study evaluated the phenolic profiles and the antioxidant activities of seven different accessions of L. alba. The seven accessions of L. alba studied exhibited an important phenolic content, and all accessions demonstrated antioxidant activity with different efficacies. The main flavonoids in all accessions were apigenin, luteolin, naringin and rutin. The Santa Vitória do Palmar accession exhibited higher naringin and total phenolic content. This extract was able to reduce hydrogen peroxide-induced oxidative damage in tissue homogenates of cerebellum, cerebral cortex, hippocampus and liver of Wistar rats.

Organic and Conventional Yerba Mate (Ilex paraguariensis A. St. Hil) Improves Metabolic Redox Status of Liver and Serum in Wistar Rats

Organic and conventional yerba mate (Ilex paraguariensis) is widely used in South America to prepare nonalcoholic drinks rich in polyphenols. These compounds are able to prevent the generation of reactive species, thus minimizing the incidence of several diseases. In this perspective, we hypothesized that yerba mate may have protective effects against pentylenetetrazol (PTZ)-induced oxidative damage in liver and serum of rats. Animals (n = 42) received distilled water (control) or yerba mate (organic or conventional) for fifteen days. Then, half of the rats of each group received 60 mg/kg PTZ intraperitoneally or saline solution. After 30 min the animals were euthanized and the liver and blood were collected. The results showed that organic and conventional yerba mate avoided PTZ-induced oxidative damage and nitric oxide production in the liver and serum of the rats. Moreover, both kinds of yerba mate prevented the decrease in enzymatic (superoxide dismutase and catalase) and non-enzymatic (sulfhydryl protein content) defenses in the liver and serum. In addition, histopathologic analysis of the liver showed that yerba mate reduced PTZ-induced cell damage. These findings indicate that yerba mate provides hepatoprotection and improves antioxidant status in the serum, which may contribute to the development of new therapeutic strategies using nutraceuticals drinks.