Anticonvulsant properties of Euterpe oleracea in mice

Effects of Selected Antioxidants on Electroretinography in Rodent Diabetic Retinopathy

Electroretinography (ERG) is a non-invasive technique for evaluating the retinal function in various ocular diseases. Its results are useful for diagnosing ocular disorders and assessing disease progression or treatment effectiveness. Since numerous studies are based on animal models, validating the ERG results from animals is pivotal. The first part of this paper presents basic information on the types of ERG tests used on rodents, and the second part describes the recorded functional changes in rodents' retinas when various antioxidant treatments for diabetic retinopathy were used. Our study showed that among the tests for diabetic retinopathy diagnosis in rodents, full-field ERG is accurate and the most commonly used, and pattern ERG and the photopic negative response of the flash ERG tests are rarely chosen. Furthermore, antioxidants generally protect retinas from functional losses. Their beneficial influence is expressed in the preserved amplitudes of the a- and b-waves and the oscillatory potentials. However, prolonging the drug exposure showed that the antioxidants could delay the onset of adverse changes but did not stop them. Future studies should concentrate on how long-term antioxidant supplementation affects the retinal function.

In vitro assessment of the genotoxic and cytotoxic effects of clarified açai (Euterpe oleracea MART) extract in a gastric cancer cell line (AGP01 cells)

Açaí (Euterpe oleracea MART) is a fruit of great importance for the Amazon region in nutritional, cultural and socioeconomic terms. In recent years, açaí has been the subject of several studies due to its beneficial properties for health, including effects against tumor cells. Therefore, the present work aimed to evaluate in vitro the genotoxic and cytotoxic effects of the clarified extract of açaí juice in a human metastatic gastric cancer cell line (AGP01 cells). For comparison purposes, a non-transformed cell line of African green monkey renal epithelial cells (VERO cells) was used. The viability assay by resazurin reduction, the comet assay, the determination of cell death by differential fluorescent dyes and the wound healing migration assay were performed. A reduction in viability was observed only in the AGP01 line within 72 h. There was no genotoxic damage or cell death (through apoptosis or necrosis) in any of the cell lines. However, açaí extract induced motility reduction in both cell lines. The reduction in cell viability and the induction of the anti-migratory effect in the AGP01 cell line opens perspectives for exploring the potential of açaí as an adjuvant in the treatment of gastric cancer.

Unmasking hidden risks: The surprising link between PDE5 inhibitors and seizure susceptibility

BACKGROUND

Phosphodiesterase 5 inhibitors (PDE5i) are the first line treatment for erectile dysfunction; however, several articles and case reports have shown central nervous system effects, that can cause seizures in susceptible patients. This study aims to describe the changes caused by the use of Sildenafil and Tadalafil through the analysis of abnormalities expressed in the electrocorticogram (ECoG) of rats and evaluate the seizure threshold response and treatment of seizures with anticonvulsants.

MATERIALS AND METHODS

The study used 108 rats (Wistar). Before surgery for electrode placement in dura mater, the animals were randomly separated into 3 experiments for electrocorticogram analysis. Experiment 1: ECoG response to using PD5i (Sildenafil 20mg/kg and Tadalafil 2.6mg/kg p.o.). Experiment 2: ECoG response to the use of PD5i in association with Pentylenetetrazole (PTZ-30 mg/kg i.p.), a convulsive model. Experiment 3: ECoG response to anticonvulsant treatment (Phenytoin, Phenobarbital and Diazepam) of seizures induced by association IPDE5 + PTZ. All recordings were made thirty minutes after administration of the medication and analyzed for ten minutes, only once. We considered statistical significance level of *p<0.05, **p<0.01 and ***p < 0.001.

RESULTS

After administration of Sildenafil and Tadalafil, there were increases in the power of recordings in the frequency bands in oscillations in alpha (p = 0.0920) and beta (p = 0.602) when compared to the control group (p<0.001). After the use of Sildenafil and Tadalafil associated with PTZ, greater potency was observed in the recordings during seizures (p<0.001), however, the Sildenafil group showed greater potency when compared to Tadalafil (p<0.05). Phenobarbital and Diazepam showed a better response in controlling discharges triggered by the association between proconvulsant drugs.

CONCLUSIONS

PDE5i altered the ECoG recordings in the rats' motor cortexes, demonstrating cerebral asynchrony and potentiating the action of PTZ. These findings demonstrate that PDE5i can lower the seizure threshold.

What We Know about Euterpe Genus and Neuroprotection: A Scoping Review

The Euterpe genus (mainly Euterpe oleracea Martius, Euterpe precatoria Martius, and Euterpe edulis Martius) has recently gained commercial and scientific notoriety due to the high nutritional value of its fruits, which are rich in polyphenols (phenolic acids and anthocyanins) and have potent antioxidant activity. These characteristics have contributed to the increased number of neuropharmacological evaluations of the three species over the last 10 years, especially açaí of the species Euterpe oleracea Martius. The fruits of the three species exert neuroprotective effects through the modulation of inflammatory and oxidative pathways and other mechanisms, including the inhibition of the mTOR pathway and protection of the blood-brain barrier, all of them intimately involved in several neuropathologies. Thus, a better understanding of the neuropharmacological properties of these three species may open new paths for the development of therapeutic tools aimed at preventing and treating a variety of neurological conditions.

Oral Treatment with the Extract of Euterpe oleracea Mart. Improves Motor Dysfunction and Reduces Brain Injury in Rats Subjected to Ischemic Stroke

Ischemic stroke is one of the principal causes of morbidity and mortality around the world. The pathophysiological mechanisms that lead to the formation of the stroke lesions range from the bioenergetic failure of the cells and the intense production of reactive oxygen species to neuroinflammation. The fruit of the açaí palm, Euterpe oleracea Mart. (EO), is consumed by traditional populations in the Brazilian Amazon region, and it is known to have antioxidant and anti-inflammatory properties. We evaluated whether the clarified extract of EO was capable of reducing the area of lesion and promoting neuronal survival following ischemic stroke in rats. Animals submitted to ischemic stroke and treated with EO extract presented a significant improvement in their neurological deficit from the ninth day onward. We also observed a reduction in the extent of the cerebral injury and the preservation of the neurons of the cortical layers. Taken together, our findings indicate that treatment with EO extract in the acute phase following a stroke can trigger signaling pathways that culminate in neuronal survival and promote the partial recovery of neurological scores. However, further detailed studies of the intracellular signaling pathways are needed to better understand the mechanisms involved.

Açaí (Euterpe oleracea Mart.) in Health and Disease: A Critical Review

The açaí palm (Euterpe oleracea Mart.), a species belonging to the Arecaceae family, has been cultivated for thousands of years in tropical Central and South America as a multipurpose dietary plant. The recent introduction of açaí fruit and its nutritional and healing qualities to regions outside its origin has rapidly expanded global demand for açaí berry. The health-promoting and disease-preventing properties of this plant are attributed to numerous bioactive phenolic compounds present in the leaf, pulp, fruit, skin, and seeds. The purpose of this review is to present an up-to-date, comprehensive, and critical evaluation of the health benefits of açaí and its phytochemicals with a special focus on cellular and molecular mechanisms of action. In vitro and in vivo studies showed that açaí possesses antioxidant and anti-inflammatory properties and exerts cardioprotective, gastroprotective, hepatoprotective, neuroprotective, renoprotective, antilipidemic, antidiabetic, and antineoplastic activities. Moreover, clinical trials have suggested that açaí can protect against metabolic stress induced by oxidation, inflammation, vascular abnormalities, and physical exertion. Due to its medicinal properties and the absence of undesirable effects, açaí shows a promising future in health promotion and disease prevention, in addition to a vast economic potential in the food and cosmetic industries.

Electroencephalographic Response in Juvenile Tambaqui, Colossoma macropomum, Exposed to Short-Term Anaesthetic Baths with Geraniol and Citronellol

The aim of this study was to evaluate the level of neuronal depression in juvenile tambaqui, Colossoma macropomum, exposed to geraniol (GRL) and citronellol (CTL) in immersion baths. A total of 36 juveniles weighing 35.2 ± 9.4 g were used, organised into six experimental groups: I-control (clean water); II-ethanol (water containing the highest volume of ethanol used in the anaesthetic pre-dilution); III-GRL induction (70 µL·L-1); IV-CTL induction (90 µL·L-1); V-GRL recovery; VI-CTL recovery. Electroencephalographic (EEG) recordings were performed for 300 s in each group. EEG tracings of the control and ethanol groups showed regular and similar activity. Upon exposure to the anaesthetics, irregularities were observed in the tracings showing neuronal excitability and increased amplitudes, mainly in the case of CTL. Overall, GRL-exposed fish showed depression of the central nervous system with low and regular tracings throughout induction, presenting a gradual recovery and stable tracings, which were consistent with an adequate general anaesthetic effect. On the other hand, fish exposed to CTL showed altered EEG activity during induction, that could be considered incompatible with an appropriate anaesthetic effect and smooth recovery, presenting high and irregular EEG tracing amplitudes.

Fruits for Seizures? A Systematic Review on the Potential Anti-Convulsant Effects of Fruits and their Phytochemicals

Epilepsy is a devastating neurological disorder. Current anti-convulsant drugs are only effective in about 70% of patients, while the rest remain drug-resistant. Thus, alternative methods have been explored to control seizures in these drug-resistant patients. One such method may be through the utilization of fruit phytochemicals. These phytochemicals have been reported to have beneficial properties such as anti-convulsant, anti-oxidant, and anti-inflammatory activities. However, some fruits may also elicit harmful effects. This review aims to summarize and elucidate the anti- or pro-convulsant effects of fruits used in relation to seizures in hopes of providing a good therapeutic reference to epileptic patients and their carers. Three databases, SCOPUS, ScienceDirect, and PubMed, were utilized for the literature search. Based on the PRISMA guidelines, a total of 40 articles were selected for critical appraisal in this review. Overall, the extracts and phytochemicals of fruits managed to effectively reduce seizure activities in various preclinical seizure models, acting mainly through the activation of the inhibitory neurotransmission and blocking the excitatory neurotransmission. Only star fruit has been identified as a pro-convulsant fruit due to its caramboxin and oxalate compounds. Future studies should focus more on utilizing these fruits as possible treatment strategies for epilepsy.

Extract of Euterpe oleracea Martius Stone Presents Anticonvulsive Activity via the GABAA Receptor

Epilepsy is one of the most common neurological diseases globally, resulting from a disorder in brain activity. This condition can be triggered by birth trauma, traumatic brain injury (TBI), infections of the brain and stroke. More than 70 million people suffer seizures caused by neurological abnormalities. Approximately 80% of all epileptic patients reside in low-income conditions or in developing countries, and over 75% of patients do not receive proper treatment. Our previous study found an anticonvulsant property of an extract of Euterpe oleracea stone (EEOS) that caused myorelaxation, sedation, and cardiac and respiratory depression after intraperitoneal administration. The present study investigated through electroencephalographic (EEG) profiling the anticonvulsant protective properties of EEOS in induced convulsing rats. Male Wistar rats were treated with EEOS (300 mg/kg), diazepam (DZP) (5 mg/kg), pentylenetetrazol (PTZ) (60 mg/kg) and flumazenil (FMZ) (0.1 mg/kg) by intraperitoneal (i.p.). Electrodes implanted on the dura mater provided EEG data in which EEOS suppressed seizure deflagration caused by PTZ. In addition, EEOS presented no significant difference in comparison to DZP, which has the same mechanism of action. After FMZ injection, a GABAA receptor antagonist blocked the anticonvulsive effect in both the DZP and EEOS groups, suggesting that EEOS exerts it action on the GABAA receptor at the benzodiazepine (BDZ) subunit.

Neuroprotective activities of acai berries (Euterpe sp.): A review

Dietary interventions rich in fruits and vegetables in aging people can reverse or mitigate age-related cognitive declines, delay the onset of neurodegenerative diseases (NDDs), and provide long-term health dividends. The novel food, popularly known as "Acai", is a berry belonging to the Euterpe genus of tropical palms trees and natively found in South America. Euterpe oleracea has been given much attention among scientists due to its high antioxidant capacity compared to other fruits and berries. Additionally, acai pulp composition analysis found that it contains various biologically active phytochemicals. In this review, we focused on current evidence relating to acai berry neuroprotection mechanisms and its efficacy in preventing or reversing neurodegeneration and age-related cognitive decline. A number of studies have illustrated the potential neuroprotective properties of acai berries. They have shown that their chemical extracts have antioxidant and anti-inflammatory properties and maintain proteins, calcium homeostasis, and mitochondrial function. Moreover, acai berry extract offers other neuromodulatory mechanisms, including anticonvulsant, antidepressant, and anti-aging properties. This neuromodulation gives valuable insights into the acai pulp and its considerable pharmacological potential on critical brain areas involved in memory and cognition. The isolated chemical matrix of acai berries could be a new substitute in research for NDD medicine development. However, due to the limited number of investigations, there is a need for further efforts to establish studies that enable progressing to clinical trials to consequently prove and ratify the therapeutic potential of this berry for several incurable NDDs.

Euterpe oleracea fruit (Açai)-enriched diet suppresses the development of experimental cerebral malaria induced by Plasmodium berghei (ANKA) infection

Background

Cerebral malaria is one of the most severe complications attributed to protozoal infection by Plasmodium falciparum, gaining prominence in children mortality rates in endemic areas. This condition has a complex pathogenesis associated with behavioral, cognitive and motor sequels in humans and current antimalarial therapies have shown little effect in those aspects. Natural products with antioxidant and anti-inflammatory properties have become a valuable alternative therapeutic option in the treatment of distinct conditions. In this context, this study investigated the neuroprotective effect of Euterpe oleracea (açai) enriched diet during the development of experimental cerebral malaria induced by the inoculation of Swiss albino mice with Plasmodium berghei ANKA strain.

Methods

After Plasmodium infection, animals were maintained on a feeding with Euterpe oleracea enriched ration and parameters such as survival curve, parasitemia and body weight were routinely monitored. The present study has also evaluated the effect of açai-enriched diet on the blood-brain barrier leakage, histological alterations and neurocognitive impairments in mice developing cerebral malaria.

Results

Our results demonstrate that between 7th–19th day post infection the survival rate of the group treated with açai enriched ration was higher when compared with Plasmodium-infected mice in which 100% of mice died until the 11th days post-infection, demonstrating that açai diet has a protective effect on the survival of infected treated animals. The same was observed in the brain vascular extravasation, where Evans blue dye assays showed significantly less dye extravasation in the brains of Plasmodium-infected mice treated with açai enriched ration, demonstrating more preserved blood-brain barrier integrity. Açai-enriched diet also attenuate the histopathological alterations elicited by Plasmodium berghei infection. We also showed a decrease of the neurological impairments arising from the exposure of cerebral parenchyma in the group treated with açai diet, ameliorating motor and neuropsychiatric changes, analyzed through the SHIRPA protocol.

Conclusion

With these results, we conclude that the treatment with açai enriched ration decreased the mortality of infected animals, as well as protected the blood-brain barrier and the neurocognitive deficits in Plasmodium-infected animals.

Dietary Euterpe oleracea Mart. attenuates seizures and damage to lipids in the brain of Colossoma macropomum

The Amazonian açai fruit (Euterpe oleracea) has shown promising anticonvulsant properties, comparable to those of diazepam (BDZ) in in vivo models submitted to pentylenetetrazole (PTZ). PTZ is a classic convulsant agent used in studies for the purpose of screening anticonvulsants and investigating the mechanisms of epilepsy. Herein, we aimed to determine, for the first time, the effect of dietary administration of lyophilized E. oleracea (LEO) on PTZ-induced seizures, using juvenile Colossoma macropomum fish (9.1 ± 1.5 g) as a model. A control diet (0.00% LEO) and two levels of LEO inclusion were established: 5.00% and 10.0% LEO (w/w). Fish were divided into five groups (n = 5): control (0.9% physiological solution; i.p.), PTZ (PTZ 150 mg kg^-1; i.p.), PTZ LEO 5.00%, PTZ LEO 10.0%, and BDZ-PTZ (BDZ: diazepam 10 mg kg^-1; i.p.). In addition to the electroencephalography (EEG), the lipid peroxidation (TBARS) was quantified in the brain, along with the characterization of behavioral responses. Fish receiving PTZ showed intense action potential bursts (APB), which overlapped with a hyperactive behavior. In PTZ LEO 5.00% and 10.0% groups, convulsive behavior was significantly reduced compared to the PTZ group. Fish fed 5.00% or 10.0% LEO and exposed to PTZ showed less excitability and lower mean amplitude in tracings. The inclusion of 10.0% LEO in the diet prevented the increase in mean amplitude of the EEG waves by 80%, without significant differences to the quantified mean amplitude of the BDZ-PTZ group. TBARS concentration was reduced by 60% in the brain of fish fed 10.0% LEO-enriched diets relative to the PTZ-administered group. The results of this study demonstrated the anticonvulsant and protective roles of LEO to the brain, and the dietary inclusion of LEO seems to be promising for the formulation of functional diets. Results of this study may boost the interest on the anti-seizurogenic properties of Euterpe oleracea, including the development of new approaches for the prevention of seizures in humans and animals with low epileptic threshold.

Eating in the Amazon: Nutritional Status of the Riverine Populations and Possible Nudge Interventions

The Amazon is the largest tropical forest in the world and a source of healthy food, such as fruits and fish. Surprisingly, the Amazonian riverine population present an increased prevalence (as high as 58%) of non-communicable diseases, such as hypertension and insulin resistance, even higher than that described for the urban population of the Amazon. Therefore, this work aimed to analyze the nutritional status and associated risk of the riverine population. Body mass index, waist circumference (WC), waist-to-hip ratio, and neck circumference (NC) were evaluated, and risk analysis was assayed. Furthermore, data about occupation and the prevalence of consumers of the different groups of food were analyzed. All anthropometric parameters revealed high proportions of individuals at risk, WC and NC being the factors that had more high-risk women and men, respectively. Our data confirmed the characteristic profile of the riverine communities with a high number of fish consumers, but also observed different patterns probably associated to a phenomenon of nutrition transition. Based on our data, some nudge interventions that take into account the principles of behavior analysis are discussed and proposed for these populations, aiming to improve the nutritional status and avoid the long-term consequences of the results showed by this work.

Myorelaxation, respiratory depression and electrocardiographic changes caused by the administration of extract of açai (Euterpe oleracea Mart.) stone in rats

The biological and pharmacological properties of natural polyphenols of the extract of Euterpe oleracea stone (EEOS) are associated with the central nervous system (CNS). To investigate the sedative and myorelaxant activity of EEOS in vivo, this study aimed to present the myorelaxant and sedative effects of EEOS in Wistar rats using spontaneous locomotor activity and motor electrophysiology. A total of 108 animals were used in the following experiments: a) behavioral tests (n = 27); b) electromyographic recordings of skeletal muscle (n = 27); c) respiratory muscle activity recordings (n = 27); d) cardiac muscle activity recordings (n = 27). The behavioral characteristics were measured according to the latency time of onset, the transient loss of posture reflex and maximum muscle relaxation. Electrodes were implanted in the gastrocnemius muscle and in the tenth intercostal space for electromyographic (EMG) signal capture to record muscle contraction, and in the D2 lead for electrocardiogram acquisition. After using the 300 mg/kg dose of EEOS intraperitoneally, a myorelaxant activity exhibited a lower frequency of contractility with an amplitude pattern of low and short duration at gastrocnemius muscle and intercostal muscle, which clearly describes a myorelaxant activity and changes in cardiac activity. The present report is so far the first study to demonstrate the myorelaxant activity of this extract, indicating an alternative route for açai stone valorization and its application in pharmaceutical fields.

New nanocarried phenobarbital formulation: Maintains better control of pentylenetetrazole-Induced seizures

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For the first time, phenobarbital was intercalated in the layered double hydroxide.

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This study evaluated the slow release efficacy of intercalated phenobarbital.

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The time of the anticonvulsant effect was verified by electroencephalographic records.

This study aims to evaluate the efficacy of slow release phenobarbital in the control of convulsions triggered by pentylenetetrazole (PTZ), verifying the time of permanence in the anticonvulsant effect through behavior and electroencephalographic records. A total of 162 male Wistar rats weighing between 100 and 120 g were divided into two groups, one for behavior analysis (n = 90) and biochemistry, and another for the acquisition of electrocorticographic record (n = 72). Hepatic enzymes were measured by obtaining a blood sample from the animals studied by means of a biochemical analysis. The procedures for electrode implant and electrocorticographic recordings were performed. The intercalation of phenobarbital in layered double hydroxide (LDH) nanocarrier allowed us to evaluate a new slow release pharmaceutical formulation based on methodologies that have proven longer residence time and lower side effects. This study demonstrates that phenobarbital can be a new perspective pharmaceutical formulation.

The Use of Euterpe oleracea Mart. As a New Perspective for Disease Treatment and Prevention

Euterpe oleracea Mart. (EO), popularly known as açaí, belongs to the Arecaceae family and grows abundantly in Brazil. The fruit of this palm tree is widely used because of its anti-inflammatory and antioxidant properties. In this review, a search for literature and patent technological prospecting has been performed on the use of EO to treat and prevent diseases as well as to prepare pharmaceutical formulations. EO leaves, fruits, and oil stand out for their large number of pharmacological activities such as anti-inflammatory, antioxidant, antimicrobial, antinociceptive, anticancer, anti-atherogenic, and healing activities, protection against metabolic syndromes such as diabetes, hypertension, and hyperlipidemia, and protection of organs such as lung, kidney, liver, heart, and nervous system. While the phytochemical composition is intrinsically linked to identified biological activities, discoveries of the past decade concerning the use of this species have shown pharmacological alternatives mainly in the treatment and prevention of breast cancer and metabolic syndromes. Although studies and inventions on the use of EO though are believed to have been important in light of the pharmacological activities found, few clinical and toxicity tests have been performed. Nevertheless, with the increase of interest in EO, this species is believed to be only at the beginning of the breakthroughs in the development of promising products for the pharmaceutical industry.

Proteomic approach underlying the hippocampal neurodegeneration caused by low doses of methylmercury after long-term exposure in adult rats

Methylmercury (MeHg) is an important toxicant that causes cognitive dysfunctions in humans. This study aimed to investigate the proteomic and biochemical alterations of the hippocampus associated with behavioural consequences of low doses of MeHg in a long-term exposure model, and to realistically mimic in vivo the result of human exposure to this toxicant. Adult Wistar male rats were exposed to a dose of MeHg at 0.04 mg kg-1 day-1 by gavage for 60 days. Total mercury (Hg) content was significantly increased in the hippocampal parenchyma. The increase in the Hg levels was capable of reducing neuron and astrocyte cell density in the CA1, CA3, hilus and dentate gyrus regions, increasing both malondialdehyde and nitrite levels and decreasing antioxidant capacity against peroxyl radicals. The proteomic analysis detected 1041 proteins with altered expression due to MeHg exposure, including 364 proteins with no expression, 295 proteins with de novo expression and 382 proteins with up- or down-regulated expression. This proteomic approach revealed alterations in pathways related to chemical synapses, metabolism, amino acid transport, cell energy, neurodegenerative processes and myelin maintenance. Therefore, even at low doses of MeHg exposure, it is possible to cause hippocampal damage in adult rats at many organisational levels, triggering oxidative stress and proteome misbalance, featuring a neurodegenerative process and culminating in long- and short-term memory and learning deficits.

Fatty Acid Amides Synthesized from Andiroba Oil (Carapa guianensis Aublet.) Exhibit Anticonvulsant Action with Modulation on GABA-A Receptor in Mice: A Putative Therapeutic Option

Epilepsy is a chronic neurological disease characterized by excessive neuronal activity leading to seizure; about 30% of affected patients suffer from the refractory and pharmacoresistant form of the disease. The anticonvulsant drugs currently used for seizure control are associated with adverse reactions, making it important to search for more effective drugs with fewer adverse reactions. There is increasing evidence that endocannabinoids can pharmacologically modulate action against seizure and antiepileptic disorders. Therefore, the objective of this study is to investigate the anticonvulsant effects of fatty acid amides (FAAs) in a pentylenetetrazole (PTZ)-induced seizure model in mice. FAAs (FAA1 and FAA2) are obtained from Carapa guianensis oil by biocatalysis and are characterized by Fourier Transform Infrared Analysis (FT-IR) and Gas Chromatography-Mass Spectrometry (GC-MS). Only FAA1 is effective in controlling the increased latency time of the first myoclonic jerk and in significantly decreasing the total duration of tonic-clonic seizures relative to the pentylenetetrazol model. Also, electrocortical alterations produced by pentylenetetrazol are reduced when treated by FAA1 that subsequently decreased wave amplitude and energy in Beta rhythm. The anticonvulsant effects of FAA1 are reversed by flumazenil, a benzodiazepine antagonist on Gamma-Aminobutyric Acid-A (GABA-A) receptors, indicating a mode of action via the benzodiazepine site of these receptors. To conclude, the FAA obtained from C. guianensis oil is promising against PTZ-induced seizures.

Towards Therapeutic Alternatives for Mercury Neurotoxicity in the Amazon: Unraveling the Pre-Clinical Effects of the Superfruit Açaí (Euterpe oleracea, Mart.) as Juice for Human Consumption

Methylmercury (MeHg) exposure is a serious problem of public health, especially in the Amazon. Exposure in riverine populations is responsible for neurobehavioral abnormalities. It was hypothesized that consumption of Amazonian fruits could protect by reducing mercury accumulation. This work analyzed the effects of commercial samples of Euterpe oleracea (EO) for human consumption (10 μL/g) against MeHg i.p. exposure (2.5 mg/Kg), using neurobehavioral (open field, rotarod and pole tests), biochemical (lipid peroxidation and nitrite levels), aging-related (telomerase reverse transcriptase (TERT) mRNA expression) and toxicokinetic (MeHg content) parameters in mice. Both the pole and rotarod tests were the most sensitive tests accompanied by increased lipid peroxidation and nitrite levels in brains. MeHg reduced TERT mRNA about 50% demonstrating a strong pro-aging effect. The EO intake, similar to that of human populations, prevented all alterations, without changing the mercury content, but avoiding neurotoxicity and premature aging of the Central Nervous System (CNS). Contrary to the hypothesis found in the literature on the possible chelating properties of Amazonian fruits consumption, the effect of EO would be essentially pharmacodynamics, and possible mechanisms are discussed. Our data already support the regular consumption of EO as an excellent option for exposed Amazonian populations to have additional protection against MeHg intoxication.

Antidepressant and Antiaging Effects of Açaí (Euterpe oleracea Mart.) in Mice

Depression is a mental disorder that affects 300 million people of all ages worldwide, but fewer than half of those with the condition receive adequate treatment. In addition, the high pharmacological refractoriness (affecting 30%-50% of patients) and toxicity of some classical antidepressants support the pursuit of new therapies. People with this condition show depressed mood, loss of pleasure, high levels of oxidative stress, and accelerated biological aging (decreased telomere length and expression of the telomerase reverse transcriptase (TERT), the enzyme responsible for telomere maintenance). Because of the close relationship between depression and oxidative stress, nutraceuticals with antioxidant properties are excellent candidates for therapy. This study represents the first investigation of the possible antidepressant and antiaging effects of commercial samples of clarified açaí (Euterpe oleracea) juice (EO). This fruit is rich in antioxidants and widely consumed. In this study, mice were treated with saline or EO (10 μL/g, oral) for 4 days and then with saline or lipopolysaccharide (0.5 mg/kg, i.p.) to induce depressive-like behavior. Only four doses of EO were enough to abolish the despair-like and anhedonia behaviors and alterations observed in electromyographic measurements. The antidepression effect of EO was similar to that of imipramine and associated with antioxidant and antiaging effects (preventing lipid peroxidation and increasing TERT mRNA expression, respectively) in three major brain regions involved in depression (hippocampus, striatum, and prefrontal cortex). Additionally, EO significantly protected hippocampal cells, preventing neuronal loss associated with the depressive-like state and nitrite level increases (an indirect marker of nitric oxide production). Moreover, EO alone significantly increased TERT mRNA expression, revealing for the first time a potent antiaging action in the brain that suggests neuroprotection against long-term age-related consequences.

Methylmercury intoxication and cortical ischemia: Pre-clinical study of their comorbidity

Stroke is one of the main causes of human disability worldwide. Ischemic stroke is mostly characterized by metabolic collapse and fast tissue damage, followed by secondary damage in adjacent regions not previously affected. Heavy metals intoxication can be associated with stroke incidence, because of their damaging action in the vascular system. Mercury, in particular, possesses a high tropism by metabolically active regions, such as the brain. In the present study we sought to evaluate whether methylmercury (MeHg) intoxication can aggravate the tissue damage caused by an ischemic stroke induced by microinjections of endothelin-1 (ET-1) into the motor cortex of adult rats. Following MeHg intoxication by gavage (0.04 mg/kg/day) during 60 days, the animals were injected with ET-1 (1 μl, 40 pmol/μl) or vehicle (1 μl). After 7 days, all animals were submitted to behavioral tests and then their brains were processed to biochemical and immunohistochemical analyses. We observed that long-term MeHg intoxication promoted a significant Hg deposits in the motor cortex, with concomitant increase of microglial response, followed by reduction of the neuronal population following ischemia and MeHg intoxication, as well as disturbance in the antioxidant defense mechanisms by misbalance of oxidative biochemistry with increase of both lipid peroxidation and nitrite levels, associated to behavioral deficits. MeHg exposure and cortical ischemia demonstrated that both injuries are able of causing significant neurobehavioural impairments in motor coordination and learning accompanied of an exacerbated microglial activation, oxidative stress and neuronal loss in the motor cortex, indicating that MeHg as a source of metabolic disturbance can act as an important increasing factor of ischemic events in the brain.

Low doses of methylmercury exposure during adulthood in rats display oxidative stress, neurodegeneration in the motor cortex and lead to impairment of motor skills

Despite the vast distribution among tissues, the central nervous system (CNS) represents the main target of methylmercury (MeHg) toxicity. However, few studies have evaluated the effects of MeHg exposure on the CNS at equivalent doses to human environmental exposure. In our study, we evaluated the motor cortex, an important area of motor control, in adult rats chronically exposed to MeHg in a concentration equivalent to those found in fish-eating populations exposed to mercury (Hg). The parameters evaluated were total Hg accumulation, oxidative stress, tissue damage, and behavioral assessment in functional actions that involved this cortical region. Our results show in exposed animals a significantly greater level of Hg in the motor cortex; increase of nitrite levels and lipid peroxidation, associated with decreased antioxidant capacity against peroxyl radicals; reduction of neuronal and astrocyte density; and poor coordination and motor learning impairment. Our data showed that chronic exposure at low doses to MeHg is capable of promoting damages to the motor cortex of adult animals, with changes in oxidative biochemistry misbalance, neurodegeneration, and motor function impairment.

The value of the Brazilian açai fruit as a therapeutic nutritional strategy for chronic kidney disease patients

Açai (Euterpe oleracea Mart.) fruit from the Amazon region in Brazil contains bioactive compounds such as α-tocopherol, anthocyanins (cyanidin 3-glycoside and cyanidin 3-rutinoside), and other flavonoids with antioxidant and anti-inflammatory properties. Moreover, the prebiotic activity of anthocyanins in modulating the composition of gut microbiota has emerged as an additional mechanism by which anthocyanins exert health-promoting effects. Açai consumption may be a nutritional therapeutic strategy for chronic kidney disease (CKD) patients since these patients present with oxidative stress, inflammation, and dysbiosis. However, the ability of açai to modulate these conditions has not been studied in CKD, and this review presents recent information about açai and its possible therapeutic effects in CKD.

Clarified Açaí (Euterpe oleracea) Juice as an Anticonvulsant Agent: In Vitro Mechanistic Study of GABAergic Targets

Seizures affect about 50 million people around the world. Approximately 30% of seizures are refractory to the current pharmacological arsenal, so, the pursuit of new therapeutic alternatives is essential. Clarified Euterpe oleracea (EO) juice showed anticonvulsant properties similar to diazepam in an in vivo model with pentylenetetrazol, a GABA_A receptor blocker. This study investigated the effects of EO on the main GABAergic targets for anticonvulsant drugs, analyzing the effect on the GABA receptor's benzodiazepine and picrotoxinin binding sites and the GABA uptake. Primary cultures of cortical neurons and astrocytes were treated with EO (0–25%) for up to 90 min. [³H]Flunitrazepam and [³H]TBOB binding, [³H]GABA uptake, cell viability, and morphology were assayed. Nonlethal concentrations of EO increased agonist binding and decreased antagonist binding in cortical neurons. Low concentrations significantly inhibited GABA uptake, especially in astrocytes, suggesting an accumulation of endogenous GABA in the synaptic cleft. The results demonstrate, for the first time, that EO can improve GABAergic neurotransmission via interactions with GABA_A receptor and modulation of GABA uptake. Understanding these molecular mechanisms will help in the treatment of seizures and epilepsy, especially in developing countries where geographic isolation and low purchasing power are the main barriers to access to adequate treatment.

Modulation of oxidative stress, inflammation, autophagy and expression of Nrf2 in hippocampus and frontal cortex of rats fed with açaí-enriched diets

OBJECTIVE

Açaí (Euterpe spp.), an exotic palm fruit, has recently emerged as a promising source of natural antioxidants with wide pharmacological and nutritional value. In this study, two different species of açaí pulp extracts, naturally grown in two distinct regions of the Amazon, namely, Euterpe oleracea Mart. (habitat: Brazilian floodplains of the Amazon) and Euterpe precatoria Mart. (habitat: Bolivian Amazon), were studied for their effects on brain health and cognition.

METHODS

Neurochemical analyses were performed in critical brain regions associated with memory and cognition of 19-month-old açaí-fed rats, in whom the cognitive benefits of açaí had been established.

RESULTS

Results indicated significant reductions (P< 0.05) in prooxidant NADPH-oxidoreductase-2 (NOX2) and proinflammatory transcription factor NF-κB in açaí-fed rats. Measurement of Nrf2 expression, a transcription factor for antioxidant enzymes, and a possible link between oxidative stress, neuroinflammation and autophagy mechanisms, indicated significant overexpression (P<0.005) in the hippocampus and frontal cortex of the açaí-fed rats. Furthermore, significant activation of endogenous antioxidant enzymes GST and SOD were also observed in the açaí-fed animals when compared to control. Analysis of autophagy markers such as p62, phospho-mTOR, beclin1 and MAP1B-LC3 revealed differential expression in frontal cortex and hippocampus, mostly indicating an upregulation in the açaí-fed rats.

DISCUSSION

In general, results were more profound for EP than EO in hippocampus as well as frontal cortex. Therefore, an açaí-enriched diet could possibly modulate Nrf2, which is known to modulate the intracellular redox status, thereby regulating the ubiquitin-proteosomal pathway, ultimately affecting cognitive function in the aging brain.