Uncaria rhynchophylla and its Major Constituents on Central Nervous System: A Review on Their Pharmacological Actions.

BACKGROUND: Uncaria rhynchophylla (Miq.) Jacks (Rubinaceae), a common herbal medicine known as Gou-teng in Chinese, is commonly used in Chinese medicine practice for the treatment of convulsions, hypertension, epilepsy, eclampsia and other cerebral diseases. The major active components of U. rhynchophylla are alkaloids, terpenoids and flavonoids. The protective effects of U. rhynchophylla and its major components on central nervous system (CNS) have become a focus of research in recent decades. OBJECTIVE: The study aimed to systematically summarize the pharmacological activities of U. rhynchophylla and its major components on the CNS. METHODS: This review summarized the experimental findings from our laboratories, together with other literature data obtained through a comprehensive search of databases including the Pubmed and the Web of Science. RESULTS: U. rhynchophylla and its major components such as rhynchophylline and isorhynchophylline have been shown to have neuroprotective effects on Alzheimer's disease, Parkinson's disease, depression, cerebral ischaemia through a number of mechanisms including anti-oxidant, anti-inflammatory actions and regulation on neurotransmitters. CONCLUSION: U. rhynchophylla and its major components have multiple beneficial pharmacological effects on CNS. Further studies on U. rhynchophylla and its major components are warranted to fully illustrate the underlying molecular mechanisms, pharmacokinetics, and toxicological profiles of these naturally occurring compounds and their potential for clinical application.

New Depsides and Neuroactive Phenolic Glucosides from the Flower Buds of Rugosa Rose ( Rosa rugosa).

The flower buds of Rosa rugosa Thunb. have been commonly used as a source of rose oil and as an ingredient in tea in eastern Asia, including China, Japan, and Korea. Repeated chromatography of a hot water extract from the flower buds of R. rugosa led to the isolation and characterization of three new depside glucosides, rosarugosides A-C (1-3), along with three phenolic compounds, one ionone glucoside, four flavonoids, and two tannins having known chemical structures. Linarionoside A and 2-phenylethyl-(6- O-galloyl)-ß-d-glucopyranoside were isolated from R. rugosa for the first time in this study. The structures of the new compounds 1-3 were elucidated by interpreting one- and two-dimensional nuclear magnetic resonance spectroscopic and mass spectrometric data. Among the isolates, a new depside glucoside (1) and two major phenolic glucosides (4 and 5) improved MK-801-induced sensorimotor gating deficits, which were measured via an acoustic startle response test in mice.

Comparison of neuropharmacological activities of methanolic extracts of Cuminum nigrum (Linn.) and Centratherum anthelminticum (Linn.) in mice.

The study is conducted to observe and investigate the effects of oral dosing of methanolic extracts of Cuminum nigrum (L) and Centratherum anthelminticum (L) on neuropharmacological activities of mice. Methanolic extracts of Cuminum nigrum (L) and Centratherum anthelminticum (L) were soluble in Dimethyl sulphoxide (DMSO) i.e. an organic solvent, so it is used in this study. Screening for anxiolytic and antidepressant effects were performed using open field test, head dip test, stationary rod test, cage crossing test, light and dark box and swimming- induced depression test. Thirty animals were divided into three groups of 10 animals each and numbered as 1 (control, on DMSO), 2(on methanolic extract of Cuminum nigrum (L), 3 (on methanolic extract of Centratherum anthelminticum (L). The extracts and DMSO were administered orally for 60 days. Any possible change in animal behavior was evaluated on day 15, 30 and 60 of dosing. The groups 2 and 3 showed significant increase (p<0.001, p<0.01) in open field activity and light and dark box test respectively, while significantly decreased activity was observed in head dip and cage crossing activity (p<0.01) after 60 days of dosing. Based on above findings, it is suggested that the extracts of Centratherum anthelminticum (L) and Cuminum nigrum (L) have antidepressant and anxiolytic potential with sedative effects.

Evaluation of neuroactive effects of ethanol extract of Schisandra chinensis, Schisandrin, and Schisandrin B and determination of underlying mechanisms by zebrafish behavioral profiling.

Schisandra chinensis, a traditional Chinese medicine (TCM), has been used to treat sleep disorders. Zebrafish sleep/wake behavioral profiling provides a high-throughput platform to screen chemicals, but has never been used to study extracts and components from TCM. In the present study, the ethanol extract of Schisandra chinensis and its two main lignin components, schisandrin and schisandrin B, were studied in zebrafish. We found that the ethanol extract had bidirectional improvement in rest and activity in zebrafish. Schisandrin and schisandrin B were both sedative and active components. We predicted that schisandrin was related to serotonin pathway and the enthanol extract of Schisandra chinensis was related to seoronin and domapine pathways using a database of zebrafish behaviors. These predictions were confirmed in experiments using Caenorhabditis elegans. In conclusion, zebrafish behavior profiling could be used as a high-throughput platform to screen neuroactive effects and predict molecular pathways of extracts and components from TCM.

ISOLATION OF NOVEL PARA-PENTYL PHENYL BENZOATE FROM MONDIA WHITEI. (HOOK.F.) SKEELS (PERIPLOCACEAE), ITS STRUCTURE, SYNTHESIS AND NEUROPHARMACOLOGICAL EVALUATION.

BACKGROUND: Mondia whitei L. (Hook. F.) Skeels (Periplocaceae) is a medicinal plant used locally in managing pain, fever, loss of appetite and as aphrodiasc in the South-Western states of Nigeria. However, the fruit is consumed habitually in the South-Eastern states of Nigeria, leading to speculation that it may possess some central nervous system effect but which has not been scientifically investigated, hence this study. METHODOLOGY: Fresh fruits of Mondia whitei were collected and identified by a taxonomist. They were chopped into small pieces and extracted with absolute ethanol. The crude extract was subjected to various chromatographic techniques to isolate a novel compound whose structure was elucidated from the analysis of the crystal data and by extensive use of spectroscopy. The structure was confirmed by synthesis. The compound was subjected to anxiolytic and sedative activity assay. Computational analysis of the receptor binding event of isolated compound at the gamma amino butyric acid A receptor was also evaluated. RESULTS: The structure of the compound was elucidated as para pentyl phenyl benzoate. The neuropharmacological evaluation of the compound indicated significant (p<0.05) depression of the central nervous system. The binding characteristics of the compound to gamma amino butyric acid A receptors appears to be more favorable than those obtained for gamma amino butyric acid, chlorpromazine, benzamidine, and is comparable with the affinity obtained for pentobarbitone and diazepam. CONCLUSION: These present data provide evidence for the role of para pentyl phenyl benzoate in the habitual consumption of the fruit as well as its central nervous system activities.

Annona muricata (Annonaceae): A Review of Its Traditional Uses, Isolated Acetogenins and Biological Activities.

Annona muricata is a member of the Annonaceae family and is a fruit tree with a long history of traditional use. A. muricata, also known as soursop, graviola and guanabana, is an evergreen plant that is mostly distributed in tropical and subtropical regions of the world. The fruits of A. muricata are extensively used to prepare syrups, candies, beverages, ice creams and shakes. A wide array of ethnomedicinal activities is contributed to different parts of A. muricata, and indigenous communities in Africa and South America extensively use this plant in their folk medicine. Numerous investigations have substantiated these activities, including anticancer, anticonvulsant, anti-arthritic, antiparasitic, antimalarial, hepatoprotective and antidiabetic activities. Phytochemical studies reveal that annonaceous acetogenins are the major constituents of A. muricata. More than 100 annonaceous acetogenins have been isolated from leaves, barks, seeds, roots and fruits of A. muricata. In view of the immense studies on A. muricata, this review strives to unite available information regarding its phytochemistry, traditional uses and biological activities.

Neuropharmacological screening of essential oil from oleo gum resin of Gardenia lucida Roxb.

ETHNOPHARMACOLOGICAL RELEVANCE: The oleo gum resin of Gardenia lucida is commonly employed in traditional medicine to treat multiple ailments, including epilepsy and mania. The essential oil isolated from it was screened for CNS activities to check if it is responsible for the claims made regarding the traditional use of the oleo gum resin. MATERIALS AND METHODS: The hypnotic and anticonvulsant activity was assessed by pentobarbitone induced hypnosis and convulsant models-Maximum electroshock (MES) and Pentylene tetrazole (PTZ) respectively. Effect on motor activity was evaluated using an actophotometer, rotarod and grip strength methods. RESULTS: The oil significantly potentiated the barbitone induced hypnosis and offered significant protection against the intensity and frequency of convulsions and mortality rate in both the convulsant models. A significant decrease in locomotion, motor impairment and loss of gripping reflex was also observed. CONCLUSION: The essential oil of the oleo gum resin of Gardenia lucida is a CNS depressant and anticonvulsant with central muscle relaxant properties. This justifies the claims made regarding the use of the oleo gum resin of Gardenia lucida in CNS disorders.

Preclinical evaluation of Trichilia catigua extracts on the central nervous system of mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Trichilia catigua preparations have been popularly used in Brazil as a tonic for the treatment of fatigue, stress, impotence, and deficiency of memory. The aim of the present study was to investigate the possible antidepressant, anxiolytic, motor and cognitive effects of the crude extract (CE) or ethyl-acetate fraction (EAF) of Trichilia catigua. Analyses of the total phenolics and total tannins content, as well as the in vitro antioxidant activity of CE and EAF were also performed. MATERIALS AND METHODS: CE (200-800 mg/kg) and EAF (100-400mg/kg) were orally administered to mice and 1h later the behavioral tests were performed. The free radical scavenging activity was measured by using 2,2-diphenyl-1-picryl-hydrazyl (DPPH) method. RESULTS: Single administration of CE (200-400 mg/kg) or EAF (100-400 mg/kg) did not change the behavior of the animals submitted to the elevated plus maze or their locomotor activity in the open field test. An antidepressant-like effect was detected with EAF (400 mg/kg) after acute administration. Both CE (800 mg/kg) and EAF (200 and 400 mg/kg), improve memory in mice as measured by an increased latency in the step-down inhibitory avoidance test. The EAF presented higher total phenolics and total tannins as compared to CE as well as it exhibited the best antioxidant activity. CONCLUSIONS: The present results showed an in vitro antioxidant activity for EAF and suggested that it may be useful for cognitive improvement. It is possible that both functional and chemical activities are related.

Effects of asiatic acid on passive and active avoidance task in male Spraque-Dawley rats.

AIM OF THE STUDY: Centella asiatica has a reputation to restore declining cognitive function in traditional medicine. To date, only a few compounds that show enhancing learning and memory properties are available. Therefore, the present study investigates the effects of for acute administration of asiatic acid (A-A) isolated from Centella asiatica administration on memory and learning in male Spraque-Dawley rats. MATERIALS AND METHODS: 4-5 weeks Spraque-Dawley rats were administered with concentration 1, 3, 5, 10, 30 mg/kg of A-A, baclofen, scopolamine and saline intra peritoneally and were evaluated for passive avoidance (PA), active avoidance (AA) and changes in blood pressure (BP). RESULTS: Treatment 30 mg/kg of A-A resulted in significantly dose-dependently improved memory, with increased retention latency to enter difference compartment in PA test compared to baclofen, saline and scopolamine. Furthermore, 30 mg/kg of A-A was significantly higher on learning abilities on 1st day but there was no significantly difference on avoidance memory ability after 7 days of retention. Low reading in blood pressure dose-dependent significantly difference was observed in the 30 mg/kg of A-A group compared to saline group. CONCLUSIONS: Administration A-A facilitated PA and AA on memory and learning and but had no effect on active avoidance on memory. Hence, may serve useful memory and learning with less effect in blood pressure in promoting memory and learning increases.

Chemical constituents and biological applications of the genus Symplocos.

The genus Symplocos has been reviewed for its chemical constituents and biological activities including traditional importance of some common species. The plants of this genus contain terpenoids, flavonoids, lignans, phenols, steroids, alkaloids, and iridoids. Terpenoids are the major constituents within the genus Symplocos and most of them exhibit antiproliferative effects. Some phenolic glycoside derivatives showed inhibitory activity against snake-venom phosphodiesterase I and human nucleotide pyrophosphatase phosphodiesterase I. The members of genus Symplocos are well known for their traditional uses in the treatment of various diseases like leprosy, gynecological disorders, ulcers, leucorrhea, menorrhagia, malaria, and tumefaction. The aim of the present paper is to review the comprehensive knowledge of the plants of this genus including the traditional uses, chemistry, and pharmacology.

Central nervous system activity of the proanthocyanidin-rich fraction obtained from Croton celtidifolius in rats.

OBJECTIVES: The aim of the present study was to evaluate the possible neurobehavioural effects in rats of the proanthocyanidin-rich fraction (PRF) isolated from the bark of Croton celtidifolius (Euphorbiaceae). METHODS: Adult Wistar rats were treated with the PRF (0.3-30 mg/kg) and evaluated in different behavioural paradigms classically used for the screening of drugs with psychoactive effects. KEY FINDINGS: Acute intraperitoneal (i.p.) administration of PRF decreased spontaneous locomotor activity (open field arena and activity cage), enhanced the duration of ethyl ether-induced hypnosis, increased the latency to the first convulsion induced by pentylenetetrazole (60 mg/kg, i.p.) and attenuated apomorphine-induced (0.5 mg/kg, i.p.) stereotyped behaviour. In lower doses, PRF (0.3 or 3 mg/kg, i.p.) increased the frequency of open arm entries in the elevated plus-maze test. CONCLUSIONS: The present findings suggest that the systemic administration of PRF induces a wide spectrum of behavioural alterations in rats, consistent with the putative existence of hypnosedative, anticonvulsant and anxiolytic compounds.

Neurobehavioral effect of essential oil of Cymbopogon citratus in mice.

Tea obtained from leaves of Cymbopogon citratus (DC) Stapf is used for its anxiolytic, hypnotic and anticonvulsant properties in Brazilian folk medicine. Essential oil (EO) from fresh leaves was obtained by hydrodistillation and orally administered to Swiss male mice 30 min before experimental procedures. EO at 0.5 or 1.0 g/kg was evaluated for sedative/hypnotic activity through pentobarbital sleeping time, anxiolytic activity by elevated plus maze and light/dark box procedures and anticonvulsant activity through seizures induced by pentylenetetrazole and maximal electroshock. EO was effective in increasing the sleeping time, the percentage of entries and time spent in the open arms of the elevated plus maze as well as the time spent in the light compartment of light/dark box. In addition, EO delayed clonic seizures induced by pentylenetetrazole and blocked tonic extensions induced by maximal electroshock, indicating the elevation of the seizure threshold and/or blockage of seizures spread. These effects were observed in the absence of motor impairment evaluated on the rotarod and open field test. Our results are in accord with the ethnopharmacological use of Cymbopogon citratus, and after complementary toxicological studies it can support investigations assessing their use as anxiolytic, sedative or anticonvulsive agent.

Review on plants with CNS-effects used in traditional South African medicine against mental diseases.

The majority of the population in South Africa use traditional health care to treat various mental conditions. In this review, we present ethnobotanical information on plants used by the traditional healers in South Africa to treat mental illnesses, specifically epilepsy, depression, age-related dementia and debilitative mental disorders. Details of the recent scientific studies conducted on some of these plants are reviewed. Extracts of Searsia chirindensis, Cotelydon orbiculata and Leonotis leonurus have shown in vivo anticonvulsant activity. Extracts from Searsia dentata and Searsia pyroides showed spontaneous epileptiform discharge in mouse cortical slices, and acted as NMDA-receptor antagonists. Apigenin, amentoflavone and agathisflavone with affinity to the benzodiazepine site on the GABA(A)-receptor were isolated from Searsia pyroides. Naringenin with affinity to the GABA(A)-benzodiazepine receptor was isolated from Mentha aquatica. Agapanthus campanulatus, Boophone disticha, Mondia whitei and Xysmalobium undulatum exhibited antidepressant-like activity in three in vivo models for depression. Amaryllidaceae alkaloids with activity to the serotonin transporter were isolated from Boophone disticha. The alkaloid mesembrine, which act as a serotonin reuptake inhibitor, was isolated from Sceletium tortuosum. Investigations of plants used to treat age-related dementia and debilitative mental disorders lead to the isolation of a number of Amaryllidaceae alkaloids with acetylcholinesterase inhibitory activity from Boophone disticha and Crinum species. Extracts of Mentha aquatica, Gasteria croucheri, Ruta graveolens and Scotia brachypetala inhibited MAO-B. Naringenin was isolated from Mentha aquatica as a MAO inhibitor. Only a small number of the more than 300 southern African plant species reported to treat or affect the CNS have been scientifically evaluated. Very few of the active compounds have been isolated and identified.

Ursolic acid plays a role in Nepeta sibthorpii Bentham CNS depressing effects.

The sedative, anticonvulsant and analgesic activity of ursolic acid, a terpenoid bioassay-isolated from Nepeta sibthorpii Bentham, was evaluated in mice. The oral administration of ursolic acid (2.3 mg/kg) produced a significant depressant effect on CNS by reducing spontaneous motor activity and the number and lethality of pentylenetetrazol (PTZ)-induced seizures. Two models of nociception, the writhing test and the hot plate test, were also used to examine the analgesic effect of ursolic acid. At a dose of 2.3 mg/kg, ursolic acid caused an inhibition of acetic acid-induced abdominal constriction, but was inactive in the hot plate test. Treatment at a higher dose (20 mg/kg) significantly increased the reaction time in the hot plate test. This effect, reversed by naloxone, evidently involves opioid receptors, but the analgesic activity of ursolic acid may be related also to the antiinflammatory and antioxidant properties of this compound.

Historical and current perspectives of neuroactive compounds derived from Latin America.

Plants and invertebrates in Latin America have contributed to a great extent in the use, discovery and development of novel neuroactive tools. Significantly, these neuroactive drugs have proven to be particularly important for our current understanding of the physiology and pharmacology of the nervous system. In addition, these discoveries have helped to build the modern and successful pharmacological business that we know today. For example, curare helped to introduce the use of muscle relaxing agents into modern surgical techniques. The discovery of cocaine from the leaves of Peruvian coca plants was instrumental in the discovery of local anesthetics. The search and discovery for useful neuroactive compounds derived from Latin America has also been ongoing in other areas and new applications for quinine, capsaicin and epibatidine were recently described. Besides these organic compounds, several peptides produced by spiders and other invertebrates to hunt their prey also induce effects in channels and membrane receptors at very low concentrations, indicating their high potency and selectivity. It is likely that new pharmaceutics will be developed from these molecules. The interest to renew the search for new compounds is timely, since largely unexplored lands, such as the Amazon and Patagonia, hold an important number of plants and animals that contain exciting new active compounds. With the introduction of new techniques to isolate, identify and characterize the molecular targets and actions of chemical entities, together with the need for more potent and selective compounds to treat neurological conditions, it is necessary to broaden the current exploratory effort in order to find more beneficial uses.

Neuropharmacological evaluation of Ginkgo biloba phytosomes in rodents.

On oral administration, Ginkgo biloba phytosomes significantly reduced pentobarbitone-induced sleeping time, produced an alteration in the general behaviour pattern, increased spontaneous motility and inhibited the chlorpromazine-induced blockade of conditioned and unconditioned responses in rodents. They exhibited both antiamnestic and antidepressant activities in the scopolamine-induced amnesia test and behavioural despair test, respectively. However, the phytosomes failed to show anticonvulsant activity. The observations suggest that the G. biloba phytosomes possess moderate antiamnestic/nootropic activity.

Clitoria ternatea and the CNS.

The present investigation was aimed at determining the spectrum of activity of the methanolic extract of Clitoria ternatea (CT) on the CNS. The CT was studied for its effect on cognitive behavior, anxiety, depression, stress and convulsions induced by pentylenetetrazol (PTZ) and maximum electroshock (MES). To explain these effects, the effect of CT was also studied on behavior mediated by dopamine (DA), noradrenaline, serotonin and acetylcholine. The extract decreased time required to occupy the central platform (transfer latency, TL) in the elevated plus maze (EPM) and increased discrimination index in the object recognition test, indicating nootropic activity. The extract was more active in the object recognition test than in the EPM. The extract increased occupancy in the open arm of EPM by 160% and in the lit box of the light/dark exploration test by 157%, indicating its anxiolytic activity. It decreased the duration of immobility in tail suspension test (suggesting its antidepressant activity), reduced stress-induced ulcers and reduced the convulsing action of PTZ and MES. The extract exhibited tendency to reduce the intensity of behavior mediated via serotonin and acetylcholine. The effect on DA- and noradrenaline-mediated behavior was not significant. In conclusion, the extract was found to possess nootropic, anxiolytic, antidepressant, anticonvulsant and antistress activity. Further studies are necessary to isolate the active principle responsible for the activities and to understand its mode of action.

CNS activities of liquid and spray-dried extracts from Lippia alba-Verbenaceae (Brazilian false melissa).

The CNS activity of Lippia alba liquid and spray-dried extracts, containing the non-volatile fraction from the leaves, was investigated. L. alba liquid extracts were prepared by percolation with EtOH 40, 60 or 80%. The liquid extracts, named ES(40%,) ES(60%) and ES(80%,) were concentrated, the ethanol eliminated and then tested in Swiss mice to evaluate its sedative and anticonvulsant effects. The animals received the extracts, orally, in doses corresponding to 200 mg of dry residue by kilogram of body weight. All mice were evaluated in the barbiturate-induced sleep test. Similarly, other groups of mice were submitted to convulsions induced by pentylenetetrazol (PTZ). The concentrated extract obtained from ES(80%) showed the most significant sedative and myorelaxant effects as well as the highest total flavonoid content (66 mg/100 g, expressed in apigenin). Two spray-dried powders, SDP(1) and SDP(2), were prepared from ES(80%) using as excipients, respectively, colloidal silicon dioxide (CSD) and CSD associated to beta-cyclodextrin. Only SDP(1) showed sedative profile similar to that presented by ES(80). In conclusion, we demonstrated that the non-volatile fraction of L. alba, extracted in ethanol 80% (v/v), presents sedative and myorelaxant effects and that, among the tested extracts, this presents the highest flavonoid content. We demonstrated also the technological feasibility of spray-dried extracts and the influence of the excipient on its sedative properties.

Effects of Panax quinquefolius L. on brainstem neuronal activities: comparison between Wisconsin-cultivated and Illinois-cultivated roots.

Brainstem neurons receiving subdiaphragmatic vagal inputs were recorded in an in vitro neonatal rat brainstem-gastric preparation. Aqueous extracts of American ginseng root (Panax quinquefolius L.) from Wisconsin and Illinois were applied to the gastric compartment or the brainstem compartment of the bath chamber to evaluate the peripheral gut or central brain effects of the extracts on brainstem unitary activity. After P. quinquefolius extract application to the gastric or brainstem compartment, a concentration-related inhibition in neuronal discharge frequency in brainstem unitary activity was observed, suggesting that P. quinquefolius plays an important role in regulating the digestive process and modulating the brain function in the rat. In this study, pharmacological effects of Wisconsin-cultivated P. quinquefolius and Illinois-cultivated P. quinquefolius were compared. Our results showed that Illinois-cultivated P. quinquefolius possesses a significantly stronger peripheral gastric as well as central brain modulating effect on brainstem neuronal activity. Data from our high performance liquid chromatography ginsenoside analysis suggest that this increase in inhibitory effects by Illinois-cultivated P. quinquefolius may be due to its different ginsenoside profile.