Acute effects of guarana (Paullinia cupana Mart.) on mouse behaviour in forced swimming and open field tests

Natural Products for the Treatment of Post-stroke Depression

Post-stroke depression (PSD) is the most frequent and important neuropsychiatric consequence of stroke. It is strongly associated with exacerbated deterioration of functional recovery, physical and cognitive recoveries, and quality of life. However, its mechanism is remarkably complicated, including the neurotransmitters hypothesis (which consists of a monoaminergic hypothesis and glutamate-mediated excitotoxicity hypothesis), inflammation hypothesis, dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis, and neurotrophic hypothesis and neuroplasticity. So far, the underlying pathogenesis of PSD has not been clearly defined yet. At present, selective serotonin reuptake inhibitors (SSRIs) have been used as the first-line drugs to treat patients with PSD. Additionally, more than SSRIs, a majority of the current antidepressants complied with multiple side effects, which limits their clinical application. Currently, a wide variety of studies revealed the therapeutic potential of natural products in the management of several diseases, especially PSD, with minor side effects. Accordingly, in our present review, we aim to summarize the therapeutic targets of these compounds and their potential role in-clinic therapy for patients with PSD.

Effects of the consumption of guarana on human health: A narrative review

Guarana (Paullinia cupana) is a plant from the Amazon region with cultural importance. Despite its early ancestral use by indigenous tribes, the first reports regarding the benefits of guarana consumption for human health were published in the 19th century. Since then, the use of guarana seed in powder and extract forms has been studied for its diverse effects on human health, such as stimulating, anti-inflammatory, antioxidant, anticancer, hypocholesterolemic, and anti-obesity effects. These effects are attributed to the high content of bioactive compounds found in guarana seeds, especially methylxanthines and flavonoids. In fact, the Brazilian Food Supplement Law has officially acknowledged guarana as a source of bioactive compounds. The number and diversity of studies focused on guarana and human health are increasing; thus, organizing and describing the available evidence on guarana and its applications is necessary to provide a framework for future studies. In this narrative review, we have organized the available information regarding guarana and its potential effects on human health. Guarana produces unique fruits with great potential for human health applications. However, the available evidence lacks human studies and mechanistic investigations. Future studies should be designed considering its applicability to human health, including intake levels and toxicity studies.

Medicinal Plants in the Treatment of Depression: Evidence from Preclinical Studies

Medicinal plants and their extracts are natural remedies with enormous potential for treating various diseases, including depression and anxiety. In the case of depression, hundreds of plants have traditionally been used in folk medicine for generations. Different plant extracts and natural products have been analyzed as potential antidepressant agents with validated models to test for antidepressant-like effects in animals, although other complementary studies have also been employed. Most of these studies focus on the possible mediators implicated in these potential effects, with dopamine, serotonin, and noradrenaline being the principal neurotransmitters implicated, both through interference with receptors and with their metabolism by monoamino oxidases, as well as through neuro-endocrine and neuroprotective effects. There are approximately 650 reports of antidepressant-like medicinal plants in PubMed; 155 of them have been compiled in this review, with a relevant group yielding positive results. Saffron and turmeric are the most relevant species studied in both preclinical and clinical studies; St. John's wort or kava have also been tested extensively. To the best of our knowledge, no review to date has provided a comprehensive understanding of the biomolecular mechanisms of action of these herbs or of whether their potential effects could have real benefits. The purpose of this narrative review is to provide an update regarding medicinal plants from the year 2000 to the present to examine the therapeutic potential of these antidepressant-like plants in order to contribute to the development of new therapeutic methods to alleviate the tremendous burden that depression causes worldwide.

Purinergic transmission in depressive disorders

Purinergic signaling involves the actions of purine nucleotides and nucleosides (such as adenosine) at P1 (adenosine), P2X, and P2Y receptors. Here, we present recent data contributing to a comprehensive overview of the association between purinergic signaling and depression. We start with background information on adenosine production and metabolism, followed by a detailed characterization of P1 and P2 receptors, with an emphasis on their expression and function in the brain as well as on their ligands. We provide data suggestive of altered metabolism of adenosine in depressed patients, which might be regarded as a disease biomarker. We then turn to considerable amount of preclinical/behavioral data obtained with the aid of the forced swim test, tail suspension test, learned helplessness model, or unpredictable chronic mild stress model and genetic activation/inactivation of P1 or P2 receptors as well as nonselective or selective ligands of P1 or P2 receptors. We also aimed to discuss the reason underlying discrepancies observed in such studies.

Aqueous extract of Paullinia cupana attenuates renal and hematological effects associated with ketoprofen

This study aimed to evaluate the effect of aqueous extract of Paullinia cupana (AEG) against ketoprofen side effects, through biochemical, hematological, and histological parameters. AEG showed antioxidant activity in the DPPH^• scavenging (IC₅₀  = 17.00 ± 1.00 µg/ml) and HPLC analysis revealed that this extract is constituted by antioxidants (caffeine, catechins, theobromine, and polyphenols). In vivo experiments in female Wistar rats demonstrated that alterations in urea, creatinine, and uric acid levels promoted (p < .05) by ketoprofen were reversed when AEG was co-administered. Ketoprofen significantly decreased the catalase levels of animal tissues (p < .05), which were restored when AEG was co-administered with the mentioned drug. Histological analysis showed that AEG protected tissues from damages caused by ketoprofen. Moreover, AEG reestablished the number of white blood cells, which had decreased when ketoprofen was administered. In conclusion, this study suggested that the association between ketoprofen and AEG may be an alternative to reduce health damages caused by this drug. PRACTICAL APPLICATIONS: Paullinia cupana, popularly known as guaraná, is commonly consumed as a beverage in Brazil and exhibits pharmacological and beneficial effects to humans. Ketoprofen is an efficacious drug employed in the treatment of inflammatory processes. However, this drug can cause several side effects in humans. Thus, the usage of natural products and plant extracts that can reduce such undesirable effects consists in a valuable strategy to be applied in therapeutic interventions.

Potential effect of herbal antidepressants on cognitive deficit: Pharmacological activity and possible molecular mechanism

ETHNOPHARMACOLOGICAL RELEVANCE

Cognitive symptom is a "core" symptom of major depressive disorder (MDD) patients with clear deficit in memory, social and occupational function, and may persist during the remitting phase. Therefore, the remission of cognitive symptom has been considered as one of the main objectives in the treatment of MDD. Herbal antidepressants have been used to treat MDD, and there has been great advances in the understanding of the ability of these herbs to improve cognitive deficit linked to brain injury and various diseases including depression, Alzheimer disease, diabetes and age-related disorders. This systematic review summarizes the evidence from preclinical studies and clinical trials of herbal antidepressants with positive effects on cognitive deficit. The potential mechanisms by which herbal antidepressants prevent cognitive deficit are also reviewed. This review will facilitate further research and applications.

MATERIALS AND METHODS

We conducted an open-ended, English restricted search of MEDLINE (PubMed), Web of Science and Scopus for all available articles published or online before 31 December 2019, using terms pertaining to medical herb/phytomedicine/phytochemical/Chinese medicine and depression/major depressive disorder/antidepressant and/or cognitive impairment/cognitive deficit/cognitive dysfunction.

RESULTS

7 prescriptions, more than 30 individual herbs and 50 phytochemicals from China, Japan, Korea and India with positive effects on the depressive state and cognitive deficit are reviewed herein. The evidence from preclinical studies and clinical trials proves that these herbal antidepressants exhibit positive effects on one or more aspects of cognitive defect including spatial, episodic, aversive, and short- and long-term memory. The action mode of the improvement of cognitive deficit by these herbal antidepressants is mediated mainly through two pathways. One pathway is to promote hippocampal neurogenesis through activating brain derived neurotrophic factor-tropomyosin-related kinase B signaling. The other pathway is to prevent neuronal apoptosis through the inhibition of neuro-inflammation and neuro-oxidation.

CONCLUSION

These herbal antidepressants, having potential therapy for cognitive deficit, may prevent pathological processes of neurodegenerative diseases. Furthermore, these herbal medicines should provide a treasure trove, which will accelerate the development of new antidepressants that can effectively improve cognitive symptom in MDD. Studies on their molecular mechanisms may provide more potential targets and therapeutic approaches for new drug discovery.

Guarana improves behavior and inflammatory alterations triggered by methylmercury exposure: an in vivo fruit fly and in vitro neural cells study

Methylmercury (MeHg) is a well-known environmental pollutant associated with neurological and developmental deficits in animals and humans. However, epidemiological data showed that people living in the Amazon region although exposed to MeHg do not present these effects probably due to the protective effect of certain foods. We hypothesized here if guarana, a highly caffeinated fruit and consumed on a daily basis by Amazon people, could have some protective effect against MeHg toxicity using two complementary approaches. To assess locomotor impairment and sleep disruption, we used fruit fly (Drosophila melanogaster) model, and to evaluate neuroinflammation, we used human SH-SY5Y neural cells by measuring inflammatory cytokines levels. Results showed that guarana had a protective effect on the locomotor activity of male fruit flies reducing the excessive sleepiness caused by MeHg and increasing daily activity. Also, guarana increased the viability of flies and attenuated neural cells mortality. In addition, guarana reduced all pro-inflammatory cytokines levels increased by MeHg, along with caspase-1, caspase -3, caspase-8, and 8-dOHG levels, whereas increased the anti-inflammatory (IL-10) cytokine levels, which was decreased by MeHg. Our study provides new insights on the protective effects of guarana on the viability, locomotor activity, sleep, and activity patterns in vivo and the in vitro neuronal anti-inflammatory effect against MeHg toxicity.

Potassium 2-(1-hydroxypentyl)-benzoate improves depressive-like behaviors in rat model

Potassium 2-(1-hydroxypentyl)-benzoate (PHPB) is a novel drug candidate for acute ischemic stroke. PHPB has been also shown to be beneficial for some neurodegenerative diseases. In this study, we demonstrated that PHPB improved depressive-like behaviors induced by chronic unpredictable mild stress (CUMS) in rats. Male SD rats were subjected to the stress for five weeks. PHPB (30 and 100 mg/kg) or fluoxetine (FLX 10 mg/kg, as positive control) was administered orally from the third week in CUMS procedure. The behavioral tests were applied and then the biochemical studies were carried out. PHPB or FLX treatment rescued the behavioral deficiency in CUMS-exposed rats. Meanwhile, PHPB normalized the enhanced level of serum corticosterone, improved hippocampal and serum BDNF levels, as well as p-CREB level in hippocampus. In addition, PHPB could reverse the reduced level of extracellular 5-HT and its metabolite 5-HIAA in prefrontal cortex (PFC) of depressed rats. In summary, our results showed that PHPB improved depression-like behaviors in CUMS-exposed rats. The mechanisms might relate to the reverse of neurotrophic disturbance in the brain, reducing excessive HPA axis response and facilitating the release of 5-HT.

Phytochemistry and pharmacology of anti-depressant medicinal plants: A review

Stress renders an individual to experience mental pressure and exhaustion which brings about feelings of anxiety, depression, anger and/or other negative emotions. Depression affects a person's state of mind, behaviour, health and is often associated with suicide. The use of anti-depressant drugs as therapeutic agents is associated with symptoms such as, delayed onset of action, side-effects, drug-drug and dietary interactions, sexual dysfunction, cardiac toxicity, etc. Thus, there is need to target these issues and improve current treatment options. Medicinal plants have long been used in discovering novel treatment strategies and compounds with promising roles in treating various disease conditions. There has been an increase, worldwide, in the use of medicinal plants and herbs for developing nutraceuticals for treatment of depression and other psychiatric disorders. Medicinal plants in their natural forms are valuable as they are rich in various phytochemical compounds. These phytochemical compounds have pharmacological roles in treating various diseases conditions; apart from being widely available in nature and commercially beneficial. The phytochemical compounds in plants are constantly being explored through various experimental studies to determine the molecular basis of how medicinal plants work in relation to drugs and diseases and to develop neutraceuticals for improving conditions. This review summarizes 110 medicinal plants and their phytochemical constituents that have been shown to possess anti-depressant activity. This review also highlights the various mechanisms of anti-depressant action of some of these plants and their plant parts like roots, stem, leaves, flowers, fruit or whole plant; phytochemical compounds showing anti-depressant activity such flavanoids, steroids, saponins, sugars, lectins, alkaloids, etc.; and various anti-depressant screening models used such as tail suspension test, forced swim test, chronic unpredictable stress test, sucrose preference test, monoamine oxidase inhibition assay, learned helplessness test, open field test, hole board test, etc. However, mechanistic evaluation of many of these plants still needs to be investigated and explored.

Camellia euphlebia exerts its antidepressant-like effect via modulation of the hypothalamic-pituitary-adrenal axis and brain monoaminergic systems

Camellia euphlebia (family, Theaceae) is a Chinese folk medicine, known for its multiple pharmacological properties. The present study aimed to provide further insights into the therapeutic basis of C. euphlebia using several animal behavioral tests and physiological indexes. Tail suspension test, forced swimming test, open-field test, chronic unpredictable mild stress (CUMS), reversal of reserpine-induced hypothermia and palpebral ptosis, and 5-hydroxytryptophane-induced head-twitch response were used to evaluate the antidepressant effect of aqueous extract of Camellia euphlebia (AEC) on mice. The possible underlying mechanism was explored by investigating the changes associated with several parameters of animal behavior, as well as the changes in monoamine neurotransmitter and stress hormone levels in these animals during the tests. Mice administered AEC at 100 and 200 mg/kg/day doses for 7 days showed significantly reduced immobility duration in forced swimming test and tail suspension test, whilst exhibiting no apparent changes in locomotor activity. Additionally, administration of AEC also effectively antagonized reserpine-induced palpebral ptosis and hypothermia and enhanced 5-hydroxytryptophane-induced head-twitch response. AEC significantly elevated the levels of serotonin, noradrenaline and dopamine in the blood and brain compared to non-treated mice. After 28 days of administration, the maximum AEC dose (100 mg/kg/day) significantly reversed CUMS-induced inhibition of weight gain and sucrose intake, while decreasing the levels of plasma adrenocorticotropic hormone and serum corticosterone. The antidepressant effect of AEC appeared to involve the alteration of hypothalamic-pituitary-adrenal axis and monoaminergic systems.

Anti-depressant and anxiolytic potential of Acacia hydaspica R. Parker aerial parts extract: Modulation of brain antioxidant enzyme status

BACKGROUND

Oxidative stress may link to psychiatric disorders, and is being regarded as a plausible mechanism that can affect the regulation of these illnesses. The present study was undertaken to investigate the antidepressant and anxiolytic potential of A. hydaspica R. parkers. Brain oxidative stress enzyme levels were analyzed to correlate depression and stress with brain antioxidant status.

METHODS

Antidepressant and anxiolytic effect of methanol extract of A. hydaspica and its derived soluble fractions [n-hexane (AHH), ethyl-acetate (AHE), chloroform (AHC), n-butanol (AHB) and remaining aqueous fraction (AHA)] was investigated by using three behavioral models; the Forced swimming test, Tail suspension test and Elevated plus-maze test (EPM). Chronic unpredictable mild stress (CMS) was employed to induce stress in rats. AHM and AHE (200 mg/kg, p.o), fluoxetine (5 mg/kg, i.p) and diazepam (DZM) (1 mg/kg, p.o) were administered during the 7 day stress exposure period, and rats were assessed for antidepressant and anxiolytic behavioral despair paradigms. Antioxidant enzymes and oxidative stress markers were measured in brain tissue of depressed rats. Phytochemical analysis was done by GCMS experimentation.

RESULTS

AHM and AHE (acute dose) significantly (p < 0.0001) reduced the immobility time and ameliorated climbing behavior as compared to the control in FST and TST, and similar to fluoxetine. AHM and AHE showed significant (p < 0.0001) anxiolytic potential in EPM, and comparable to DZM (1 mg/kg b.w., i.p). Significant decrease in antioxidant enzyme levels and increase in MDA, H2O2 and NO level were observed in stressed rats. AHM and AHE (for 7 days/CMS) significantly improved behavior in FST, TST and EPMT. Treatment also improved antioxidant enzyme level and controlled the oxidative stress markers in brain tissues. GCMS analysis indicated the presence of 10 different chemical constituents in A. hydaspica.

CONCLUSION

The present study revealed that A. hydaspica exerts an antidepressant and anxiolytic effect by improving brain antioxidant status. The observed activities might be due to the presence of diverse phytochemicals.

Acute effectiveness of a "fat-loss" product on substrate utilization, perception of hunger, mood state and rate of perceived exertion at rest and during exercise

BACKGROUND

Achieving fat-loss outcomes by ingesting multi-ingredient mixtures may be further enhanced during exercise. This study tested the acute thermogenic effectiveness of a commercially available multi-ingredient product (Shred-Matrix®), containing Green Tea Extract, Yerba Maté, Guarana Seed Extract, Anhydrous caffeine, Saw palmetto, Fo-Ti, Eleuthero root, Cayenne Pepper, and Yohimbine HCI, on fatty acid oxidation (FAO), perception of hunger, mood state and rate of perceived exertion (RPE) at rest and during 30 min of submaximal exercise.

METHODS

Following institutional ethical approval, twelve healthy recreationally active participants, five females and seven males, were randomized to perform two separate experimental ergometry cycling trials, and to ingest 1.5 g (3 × capsules) of either a multi-ingredient supplement (SHRED) or placebo (PL). Participants rested for 3 h, before performing a 30-min cycling exercise corresponding to their individually-determined intensity based on their maximal fat oxidation (Fatmax). Fatty acid oxidation (FAO) was determined at rest, 3 h before exercise (Pre1), immediately before exercise (Pre2) and during exercise (Post), using expired gasses and indirect calorimetry. Rate of perceived exertion (RPE) was measured every 3 min during the 30-min exercise. Additionally both mood state and perception of hunger were assessed at Pre1, Pre2 and Post exercise. A repeated measures ANOVA design and Cohen's d effect sizes were used to analyze potential differences between times and treatment conditions.

RESULTS

FAO increased in SHRED from Pre1 to Pre2 [0.56 ± 0.26 to 0.96 ± 0.37, (p = 0.003, d =1.34)] but not in PL [0.67 ± 0.25 to 0.74 ± 0.19, (p = 0.334) d = 0.49], with no differences were found between conditions (p = 0.12, d = 0.49). However, Cohen's d = 0.77 revealed moderate effect size in favor of SHRED from Pre to Post exercise. RPE values were lower in SHRED compared to Pl (p< 0.001). Mood state and perception of hunger were not different between conditions, with no interaction effects. However, a trend was shown towards improved satiety in SHRED compared with PL, [F(1,11) = 3.58, p = 0.085].

CONCLUSIONS

The multi-ingredient product's potential enhancement of FAO during exercise, satiety, and RPE reduction suggests an acute effectiveness of SHRED in improving the exercise-related fat loss benefits.

Evaluation of the Anxiolytic and Antidepressant Activities of the Aqueous Extract from Camellia euphlebia Merr. ex Sealy in Mice

Camellia euphlebia Merr. ex Sealy is a traditional Chinese medicine that has been widely used for improvement of human emotions in the Guangxi Province of southern China. However, there are no studies about the anxiolytic and antidepressant activities of Camellia euphlebia. This study evaluated the anxiolytic and antidepressant activities of the aqueous extract from Camellia euphlebia (CEE) in mice. We found that administration of 400 mg/kg CEE or 20 mg/kg fluoxetine for 7 days significantly reduced the immobility time in both TST and FST. Oral administration of 100 mg/kg extract or 4 mg/kg diazepam for 7 days significantly increased the percentage of time spent and the number of entries into the open arms of the EPMT. In addition, the time spent by mice in the illuminated side of the LDBT was increased. Furthermore, pretreatment with 400 mg/kg CEE for 7 days significantly elevated the level of 5-HT and DA in the whole brain of mice. These results provide support for the potential anxiolytic and antidepressant activity of Camellia euphlebia and contribute towards validation of the traditional use of Camellia euphlebia in the treatment of emotional disorders.

Protective effect of the orientin on noise-induced cognitive impairments in mice

There is increasing evidence that chronic noise stress impairs cognition and induces oxidative stress in the brain. Recently, orientin, a phenolic compound abundant in some fruits, millet, and herbs, has been shown to have antioxidant properties. This study investigated the potential effects of orientin against chronic noise-induced cognitive decline and its underlying mechanisms. A moderate-intensity noise exposure model was used to investigate the effects of orientin on behavior and biochemical alterations in mice. After 3 weeks of the noise exposure, the mice were treated with orientin (20mg/kg and 40 mg/kg, oral gavage) for 3 weeks. The chronic noise exposure impaired the learning and memory in mice in the Morris water maze and step-through tests. The noise exposure also decreased exploration and interest in a novel environment in the open field test. The administration of orientin significantly reversed noise-induced alterations in these behavior tests. Moreover, the orientin treatment significantly improved the noise-induced alteration of serum corticosterone and catecholamine levels and oxidative stress in the hippocampus and prefrontal cortex. Furthermore, the orientin treatment ameliorated the noise-induced decrease in brain-derived neurotrophic factor and synapse-associated proteins (synaptophysin and postsynaptic density protein 95) in the hippocampus and prefrontal cortex. Thus, orientin exerts protective effects on noise-induced cognitive decline in mice, specifically by improving central oxidative stress, neurotransmission, and increases synapse-associated proteins. Therefore, supplementation with orientin-enriched food or fruit could be beneficial as a preventive strategy for chronic noise-induced cognitive decline.

Guarana provides additional stimulation over caffeine alone in the planarian model

The stimulant effect of energy drinks is primarily attributed to the caffeine they contain. Many energy drinks also contain other ingredients that might enhance the tonic effects of these caffeinated beverages. One of these additives is guarana. Guarana is a climbing plant native to the Amazon whose seeds contain approximately four times the amount of caffeine found in coffee beans. The mix of other natural chemicals contained in guarana seeds is thought to heighten the stimulant effects of guarana over caffeine alone. Yet, despite the growing use of guarana as an additive in energy drinks, and a burgeoning market for it as a nutritional supplement, the science examining guarana and how it affects other dietary ingredients is lacking. To appreciate the stimulant effects of guarana and other natural products, a straightforward model to investigate their physiological properties is needed. The planarian provides such a system. The locomotor activity and convulsive response of planarians with substance exposure has been shown to provide an excellent system to measure the effects of drug stimulation, addiction and withdrawal. To gauge the stimulant effects of guarana we studied how it altered the locomotor activity of the planarian species Dugesia tigrina. We report evidence that guarana seeds provide additional stimulation over caffeine alone, and document the changes to this stimulation in the context of both caffeine and glucose.

Screening of antidepressant activity and estimation of quercetin from Coccinia indica using TLC densitometry

CONTEXT

Coccinia indica Naud (Cucurbitaceae) has been traditionally used for the treatment of depression but these claims have not been validated.

OBJECTIVES

The objective of this study is to investigate antidepressant activity of various extracts and fractions of C. indica aerial parts, and to estimate content of quercetin in the plant using TLC densitometry.

MATERIALS AND METHODS

Coccinia indica aerial parts were successively extracted using solvents in increasing order of polarity, namely n-hexane, chloroform, methanol, and water. Various extracts were evaluated for antidepressant activity at doses of 200 or 400 mg/kg, p.o., upon acute administration in mice using the forced swim test (FST). The bioactive extract was partitioned successively using solvents in increasing order of polarity, namely n-hexane, ethyl acetate, and n-butanol. All fractions were also screened for antidepressant activity at doses of 25 or 50 mg/kg, p.o., upon acute administration in mice.

RESULTS

The methanol extract significantly reduced the duration of immobility in FST at dose of 400 mg/kg without affecting locomotor activity in open field test, thus, confirmed its antidepressant activity, which was statistically equivalent to the standard drug (imipramine, 15 mg/kg, i.p.). Ethyl acetate fraction (EAF) exhibited antidepressant activity at 50 mg/kg. Comparative TLC fingerprint studies confirmed the presence of quercetin in methanol extract and EAF. Quercetin was used as a chemical marker to standardize C. indica aerial parts using the validated TLC densitometric method, and the content of quercetin was found to be 0.00172% w/w.

CONCLUSIONS

The present studies scientifically validated traditional claims of C. indica for antidepressant activity.

Heart rate variability and cognitive function following a multi-vitamin and mineral supplementation with added guarana (Paullinia cupana)

The aim of this study was to assess cognitive performance and heart rate variability (HRV) following the ingestion of either a multi-vitamin-mineral preparation supplemented with 300 mg guarana (Ac); a caffeine supplement (C) or a placebo supplement (Pl). Fifty-six subjects took part in a randomized, double-blind crossover design, consisting of three experimental sessions ran on a different day. Cognitive performance was assessed using a go/no-go task and a simple reaction time (SRT) task. HRV was assessed in the time domain (RMSSD) and in the frequency domain (HF) and cognitive tasks were performed before ingestion, 15 min after ingestion and then every 15 min over the course of 3 h. Responses were faster (without change in accuracy) when the go/no-go task was performed between 30 and 90 min after ingestion of Ac (4.6% ± 0.8%, p < 0.05). No effect was observed on SRT task. A significant decrease in HRV was observed during the first hour under C and Pl, whereas HRV remained stable under Ac. The results suggest that the ingestion of a multi-vitamin-mineral with added guarana improves decision-making performance and is accompanied by a stable autonomic nervous system regulation during the first hour.

Emodin opposes chronic unpredictable mild stress induced depressive-like behavior in mice by upregulating the levels of hippocampal glucocorticoid receptor and brain-derived neurotrophic factor

Emodin, the major active component of Rhubarb, has shown neuroprotective activity. This study is attempted to investigate whether emodin possesses beneficial effects on chronic unpredictable mild stress (CUMS)-induced behavioral deficits (depression-like behaviors) and explore the possible mechanisms. ICR mice were subjected to chronic unpredictable mild stress for 42 consecutive days. Then, emodin and fluoxetine (positive control drug) were administered for 21 consecutive days at the last three weeks of CUMS procedure. The classical behavioral tests: open field test (OFT), sucrose preference test (SPT), tail suspension test (TST) and forced swimming test (FST) were applied to evaluate the antidepressant effects of emodin. Then plasma corticosterone concentration, hippocampal glucocorticoid receptor (GR) and brain-derived neurotrophic factor (BDNF) levels were tested to probe the mechanisms. Our results indicated that 6 weeks of CUMS exposure induced significant depression-like behavior, with high, plasma corticosterone concentration and low hippocampal GR and BDNF expression levels. Whereas, chronic emodin (20, 40 and 80 mg/kg) treatments reversed the behavioral deficiency induced by CUMS exposure. Treatment with emodin normalized the change of plasma corticosterone level, which demonstrated that emodin could partially restore CUMS-induced HPA axis impairments. Besides, hippocampal GR (mRNA and protein) and BDNF (mRNA) expressions were also up-regulated after emodin treatments. In conclusion, emodin remarkably improved depression-like behavior in CUMS mice and its antidepressant activity is mediated, at least in part, by the up-regulating GR and BDNF levels in hippocampus.

Protective effects of the novel adenosine derivative WS0701 in a mouse model of posttraumatic stress disorder

AIM

To investigate the effects of the novel N6-substituted adenosine derivative {(2R,3S,4R,5R)-3,4-dihydroxy-5-[6-[(4-hydroxy-3-methoxybenzyl)amino]-9H-purin-9-yl]tetrahydrofuran-2-yl} methyl decanoate (WS0701) on stress-induced excessive fear, anxiety, and cognitive deficits in a mouse model of posttraumatic stress disorder (PTSD).

METHODS

Male mice underwent a conditioned foot shock and single prolonged stress procedure to induce PTSD. Contextual/cued fear, elevated plus-maze, open field and novel object recognition tests were conduced to assess PTSD-like behaviors. From d 1, the mice were orally administered WS0701 (7.5, 15, or 30 mg·kg(-1)·d(-1)) or paroxetine (10 mg·kg(-1)·d(-1)) for two weeks. Apoptosis of hippocampal neurons was detected using flow cytometry and TUNEL staining, and expression of Bcl-2 and Bax in the hippocampus was measured with Western boltting and qPCR assays.

RESULTS

WS0701 administration significantly alleviated fear, anxious behaviors and memory deficits in the mouse model of PTSD. Furthermore, WS0701 administration significantly reduced the stress-induced apoptosis of hippocampal neurons, and increased the Bcl-2/Bax ratio in the hippocampus. The positive control drug paroxetine exerted similar effects on PTSD-like behaviors and hippocampal neuron apoptosis in the mouse model of PTSD, which were comparable to those caused by the high dose of WS0701.

CONCLUSION

WS0701 effectively mitigates stress-induced PTSD-like behaviors in mice, partly via inhibition of neuronal apoptosis in the hippocampus.

Guarana: revisiting a highly caffeinated plant from the Amazon

ETHNOPHARMACOLOGICAL RELEVANCE

Guarana (Paullinia cupana Kunth var. sorbilis (Mart.) Ducke) has been traditionally consumed by indigenous communities of the Amazon region. It is valued mainly for its stimulant property because of its high content of caffeine, which can be up to 6% in the seeds.

AIM OF THE REVIEW

The purpose of this review is to revisit this typically Brazilian plant, addressing economic considerations, the chemical makeup of the seeds and pharmacological properties so far investigated.

RESULTS

Guarana is primarily produced in the Brazilian states of Amazonas and Bahia, and approximately 70% of the production is used by the industry of soft and energy drinks. The other 30% becomes guarana powder for direct consumption in capsules or dilution in water, or it serves as a raw material for the pharmaceutical and cosmetics industries. In addition to its stimulant property, guarana has other therapeutic properties, which have aroused the interest of the scientific community.

CONCLUSION

This review shows that other guarana properties may be explored and how scarce are the studies regarding agronomic, plant pathology, physiology and breeding. So far, caffeine has been the main reason to study guarana and still will lead the researches because the demand for this alkaloid by food and pharmaceutical industry, and a strongly growing market related with beauty products. However, guarana has other components and there is great interest in studies designed to elucidate the effects of guarana's bioactive components and their potential pharmacological applications. Significant part of the guarana production in Brazil still comes from Indians tribes in the Amazon State, and any improvement in this plant, in any aspect, may propitiate a positive economic impact in their lives.

Pharmacological classification of herbal extracts by means of comparison to spectral EEG signatures induced by synthetic drugs in the freely moving rat

Herbal extracts targeting at the brain remain a continuous challenge to pharmacology. Usually, a number of different animal tests have to be performed in order to find a potential clinical use. Due to manifold possibly active ingredients biochemical approaches are difficult. A more holistic approach using a neurophysiological technique has been developed earlier in order to characterise synthetic drugs. Stereotactic implantation of four semi-microelectrodes into frontal cortex, hippocampus, striatum and reticular formation of rats allowed continuous wireless monitoring of field potentials (EEG) before and after drug intake. After frequency analysis (Fast Fourier Transformation) electric power was calculated for 6 ranges (delta, theta, alpha1, alpha2, beta1 and beta2). Data from 14 synthetic drugs - tested earlier and representative for different clinical indications - were taken for construction of discriminant functions showing the projection of the frequency patterns in a six-dimensional graph. Quantitative analysis of the EEG frequency pattern from the depth of the brain succeeded in discrimination of drug effects according to their known clinical indication (Dimpfel and Schober, 2003). Extracts from Valerian root, Ginkgo leaves, Paullinia seed, Hop strobile, Rhodiola rosea root and Sideritis scardica herb were tested now under identical conditions. Classification of these extracts based on the matrix from synthetic drugs revealed that Valerian root and hop induced a pattern reminiscent of physiological sleep. Ginkgo and Paullinia appeared in close neighbourhood of stimulatory drugs like caffeine or to an analgesic profile (tramadol). Rhodiola and Sideritis developed similar frequency patterns comparable to a psychostimulant drug (methylphenidate) as well to an antidepressive drug (paroxetine).

Protective effects of luteolin on cognitive impairments induced by psychological stress in mice

In the present study, the protective effects of luteolin were investigated against psychological stress-induced cognitive impairment. To emulate the psychological stress, mice received restraint stress for six hours daily, between 9:00 and 15:00 hours, for 21 consecutive days. The results of step-through test, open-field test and Morris Water Maze test demonstrated that psychological stress treatment could result in cognitive impairments in mice. This cognition dysfunction was improved by treatment with low- and medium-dose luteolin. In addition, psychological stress induced an increased serum corticosterone concentration with a decreased serum norepinephrine and dopamine concentration. These alterations were attenuated by treatment with luteolin. Also, psychological stress significantly decreased the glutathione (GSH) concentrations and superoxide dismutase (SOD) activities in prefrontal cortex and hippocampus, while the malondialdehyde (MDA) concentrations were enhanced. However, these oxidative alterations in prefrontal cortex and hippocampus induced by psychological stress were significantly reversed by treatment of luteolin. Further, the current study indicated a decline of catalase (CAT) activities in the hippocampus of the ST group, which was significantly prevented by low, medium and high dose of luteolin. On the other hand, there was no significance in CAT activities of the prefrontal cortex among the six groups. Collectively, the present results suggest that luteolin treatment serves as a key role in improving the psychological stress-induced cognitive impairments.

Amazonian Brazilian medicinal plants described by C.F.P. von Martius in the 19th century

ETHNOPHARMACOLOGICAL RELEVANCE

Information regarding the use of beneficial, native Brazilian plants was compiled by European naturalists during the 19th century. The German botanist C.F.P. von Martius was one of the most prominent naturalists and described the use of several Brazilian plants.

AIM OF THE STUDY

To present data on Amazonian medicinal plants documented by von Martius in his books.

MATERIALS AND METHODS

Data on Amazonian medicinal plants were obtained from three books published by von Martius. Traditional information about these plants was translated from Latin and the cited plant species reorganised according to current taxonomic criteria. Correlated pharmacological studies were obtained from different scientific databases.

RESULTS

A total of 92 native medicinal species from the Amazon were recorded in von Martius' books. These accounts described 117 different medical uses for these plants. Several parts of the plants were used, including many exudates. The principal use of the species recorded was the treatment of dermatological problems, followed by gastro-intestinal, urinary and respiratory disorders. Few species were recorded as purgatives and febrifuges, a result that differs from the observations of other naturalists. The efficacy of the recorded traditional uses has been confirmed for the few species that have been subjected to laboratory studies.

CONCLUSION

The data recorded by the German naturalist von Martius represent a rich, unexplored source of information about the traditional uses of Brazilian plants.

Antidepressant-like effects of tea polyphenols on mouse model of chronic unpredictable mild stress

Tea polyphenols (TPs), which are the natural compounds extracted from tea leaves, possess a number of beneficial properties, such as reducing the risks of cancer and heart diseases, alleviating cognitive impairments and showing antidepressant-like activity in the forced swim test (FST) and tail suspension test (TST). The present study was designed to investigate the protective effect of TPs on the chronic unpredictable mild stress (CUMS)-induced depression model in mice and to elucidate the related underlying mechanisms. With the daily exposure to stressor for 5 consecutive weeks, TPs were administered in mice at a daily dose of 25 mg/kg or 50 mg/kg by gavage for 3 consecutive weeks from the 3rd week. Our results showed that CUMS significantly decreased the levels of serum serotonin (5-HT) and norepinephrine (NE) in the hippocampus, the prefrontal cortex and serum, and the activities of superoxide dismutase (SOD) and catalase (CAT), with an increase in lipid peroxidation level as well as a reduction in glutathione (GSH) level and an elevation in the production of malondialdehyde (MDA) in the hippocampus and the prefrontal cortex. CUMS also reduced open-field activity, sucrose consumption, as well as increased immobility duration in FST and TST. TPs administration could effectively reverse the alterations in the concentrations of 5-HT and NE, elevate the activities of SOD and CAT as well as the level of GSH, reduce the MDA level and inhibit lipid peroxidation. Moreover, TPs could effectively reverse alterations in immobility duration, sucrose consumption and open-field activity. In conclusion, TPs administration has exhibited significant antidepressant-like effects in mice with CUMS-induced depression. The antidepressant activity of TPs might be related to the alteration of monoaminergic responses and antioxidant defenses.

Antidepressant-like effects of L-theanine in the forced swim and tail suspension tests in mice

L-theanine (γ-glutamylethylamide), an amino acid component of green tea, has been shown to reduce mental and physical stress, and to improve memory function. In this study, the antidepressant effect of L-theanine was investigated in mice using the forced swim test, tail suspension test, open-field test and reserpine test. L-theanine produced an antidepressant-like effect, since the administration of L-theanine at doses of 1, 4 and 20 mg/kg for 10 successive days significantly reduced the immobility time in both the forced swim test and tail suspension test, compared with the control group, without accompanying changes in ambulation in the open-field test. Moreover, L-theanine significantly antagonized reserpine-induced ptosis and hypothermia. Taken together, these results indicate that L-theanine possessed an antidepressant-like effect in mice, which may be mediated by the central monoaminergic neurotransmitter system.

Habitual intake of guaraná and metabolic morbidities: an epidemiological study of an elderly Amazonian population

The aim of the present study was to evaluate the associations of metabolic disorders and anthropometric and biochemical biomarkers of lipid, glucose and oxidative metabolism and the habitual ingestion of guaraná (Paullinia cupana, Mart. Var. sorbilis) by an elderly population residing in the Amazon Riverine region of the Maués municipality (Brazil). A case-controlled study was performed that included 637 elderly (≥60 years of age) patients classified as either those who habitually drank guaraná (GI, n = 421) or those who never drank guaraná (NG, n = 239) based upon their self-reported intake of guaraná. Indeed, the prevalence of various metabolic disorders was associated with guaraná ingestion. The prevalence of hypertension, obesity and metabolic syndrome in the GI group was lower than the prevalence found in the NG group. The NG group exhibited lower systolic and diastolic blood pressure values. The males in the GI group exhibited a lower waist circumference, on average, than the circumference found in the NG group, whereas the females in the GI group had lower cholesterol (total and LDL-c) levels than the control cohort. Additionally, a significant association was found between lower levels of advanced oxidative protein product (AOPP) and habitual guaraná consumption. The results constitute the first epidemiological study to suggest a potentially protective effect of habitual guaraná ingestion against metabolic disorders in elderly subjects.

Brazilian plants as possible adaptogens: an ethnopharmacological survey of books edited in Brazil

In a survey, from Brazilian books, we searched plants that are in popular use for purposes resembling those of an adaptogen. This study focused on 24 books by authors from diverse regions in the country, resulting in a total of 1317 citations of uses related to a possible adaptogen effect from approximately 766 plants. Only species native to Brazil, cited in at least four books, were selected, resulting a total of 33 species, belonging to 24 families. Of these, four species have been studied previously in relation to effects that are considered as part of an adaptogen effect (anti-stress, memory enhancement, increased physical and/or sexual performance): Heteropterys aphrodisiaca (Malpighiaceae), Paullinia cupana (Sapindaceae), Ptychopetalum olacoides (Olacaceae), and Turnera diffusa (Turneraceae). Three others--Pfaffia glomerata, Pfaffia paniculata (Amaranthaceae), and Trichilia catigua (Meliaceae)--have also been the object of pharmacological studies that support their use as a possible adaptogen, but they are listed in less than four books. The overall results obtained in the present review of Brazilian folk literature reveals that Brazil is rich in plants with potential adaptogen-like effect, but lacks pharmacological studies (mostly clinical ones) to confirm these therapeutic properties.