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Lippia multiflora Moldenke (Verbenaceae) is an aromatic plant used as a popular medicine with antidepressant, antispasmodic, antifungal, anti-inflammatory, and antioxidant properties. In this study, we explored the effects of L. multiflora in mice chronic model of temporal lobe epilepsy induced by pilocarpine and kindled with pentylenetetrazol. Mice were divided into 7 groups of 10 animals, and received a single dose of pilocarpine (360 mg/kg, i.p.), 20 min after the administration of N-methyl-scopolamine (1 mg/kg, i.p). Thirty days after the induction of status epilepticus , animals were daily treated for 60 days with distilled water (10 mL/kg, per os ) for the negative control group, extract (23.07, 57.69, 115.39 and 230.78 mg/kg, per os ) for the test groups, and sodium valproate (300 mg/kg, i.p) for the positive control group. On every 10th day, animals were injected with a sub-convulsive dose of pentylenetetrazol (15 mg/kg, i.p) 1 h after the administration of the various treatments to assess the susceptibility of animals to seizures. At the end of behavioural tests, animals were sacrificed and the level of inflammatory cytokines was assessed in the hippocampus. The plant extract reduced (p < 0.001) the occurrence of seizures and the number of spontaneous recurrent seizures induced by pilocarpine in mice. It ameliorated the levels of inflammatory cytokines (TNF-α, INF- γ, IL-1β, IL-6, and IL-10) in the hippocampus. The in vitro studies show that L. multiflora have a high amount of total phenolic content, flavonoids and tannins and also have some good antioxidant properties. These results suggest that L. multiflora aqueous extracts has the potential to be a promising complementary and alternative medicine for the treatment of epilepsy, due to its antiepileptic, anti-inflammatory and antioxidant effects., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Ethnopharmacological Relevance: Epilepsy is a neurological disorder of the brain characterized by periodic and unpredictable occurrence of a transient behavior alteration due to the rhythmic, synchronous and disordered firing of brain neuron. Worldwide, approximately 50 million people currently live with epilepsy and close to 80% of people with epilepsy live in poor countries. However, it was noticed in many countries worldwide that people with epilepsy and their families suffer from stigma and discrimination and that situation exposes them to high psychological conditions such as depression and anxiety as well as more physical problems including bruising and fractures from injuries related to seizures. However, several plants-based products used for epilepsy and anxiety treatments in different system of folk medicine have exhibited a significant anti-epileptic and antianxiety activities using animal models with fewer side effects., Aim of the Study: The study aimed at evaluating the antiepileptic, status post-epilepticus and anxiolytic effects of Cymbopogon giganteus decoction in rat model induced by pilocarpine., Materials and Methods: A total of 90 rats were partitioned into 7 groups and treated as follow: animals of groups I (normal control) and II (considered the negative control) received distilled water (10 mL/kg); while groups III, IV, V, and VI were treated with the C. giganteus extract at 34, 85, 170 and 340 mg/kg p.o, respectively; and the group VII (considered positive control) received sodium valproate at 300 mg/kg, i.p. After 40 min post-treatment, a single dose of n-methyl-scopolamine (1 mg/kg, i.p) was administered to animals of groups (II, III, IV, V, VI, VII) followed by pilocarpine (360 mg/kg, i.p). Animal of group I (normal group) received distilled water. Rats were further observed for 6 h to evaluate the severity and the duration of the acute seizures of epilepsy according to Racine scale. Anxious behavior status post-epilepticus was also assessed in the same rats used above in the Elevated Plus Maze and number of entries into the open or closed arms and the time spent on either open or closed arms of the platform were recorded. Animals were also evaluated on Open Field Test and the number of rearing, crossing, grooming, defecation and center time were registered., Results: C. giganteus decoction significantly (P < 0.05) reduced the animal mortality, the number and duration of convulsions and effectively increased the latency of convulsions. The plant extract significantly (P < 0.05) improved GSH level and SOD activity, reduced MDA and CAT activity, increased GABA level and decreased GABA-t activity in hippocampus. The anxiety induced by pilocarpine was also significantly (P < 0.05) inhibited by the extract of the plant., Conclusions: Thus, C. giganteus has demonstrated its antiepileptic and anxiolytic activities in rat model and may be used as preventive measure for patients suffering from epilepsy seizures and anxiety., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Alzheimer's disease is first characterised by memory loss related to the central cholinergic system alteration. Available drugs provide symptomatic treatment with known side effects. The present study is aimed to evaluate the properties of Carissa edulis aqueous extract on a Scopolamine mouse model as an attempt to search for new compounds against Alzheimer's disease-related memory impairment. Memory impairment was induced by administration of 1 mg/kg (i.p.) of Scopolamine for 7 days, and mice were treated with Carissa edulis aqueous extract. Behavioural studies were performed using T-maze and novel object recognition task for assessing learning and memory and open field test for locomotion. Brain acetylcholinesterase enzyme (AChE) activity was measured to evaluate the central cholinergic system. The level of MDA, glutathione, and catalase activity were measured to evaluate the oxidative stress level. Administration of Scopolamine shows a decrease in learning and memory enhancement during behavioural studies. A significant decrease in the time spent in the preferred arm of T-maze, in the time spent in the exploration of the novel object, and in the discrimination index of the familiar object was also observed. The significant impairment of the central cholinergic system was characterised in mice by an increase of AChE activity to 2.55 ± 0.10 mol/min/g with an increase in oxidative stress. Treatment with the different doses of Carissa edulis (62.8, 157, 314, and 628 mg/kg orally administrated) significantly increased the memory of mice in T-maze and novel object recognition tests and also ameliorated locomotion of mice in the open field. Carissa edulis aqueous extract treatment also decreases the AChE activity and brain oxidative stress. It is concluded that administration of Carissa edulis aqueous extract enhances memory of mice by reducing AChE activity and demonstrating antioxidant properties. This could be developed into a novel therapy against memory impairment related to Alzheimer's disease., Competing Interests: The authors declare that there is no conflict of interest., (Copyright © 2020 Fanta Sabine Adeline Yadang et al.)

Background: Epilepsy is a chronic neurological disorder affecting more than 50 million people worldwide, of whom 80% live in low- and middle-income countries. Due to the limited availability of antiseizure drugs (ASDs) in these countries, medicinal plants are the first-line treatment for most epilepsy patients. In Cameroon, a decoction of Cyperus articulatus L. rhizomes is traditionally used to treat epilepsy., Purpose: The aim of this study was to identify and isolate the active compounds responsible for the antiseizure activity of C. articulatus in order to confirm both its traditional medicinal usage and previous in vivo studies on extracts of this plant in mouse epilepsy models., Methods: The dried rhizomes of C. articulatus were extracted with solvents of increasing polaritie (hexane, dichloromethane, methanol and water). A traditional decoction and an essential oil were also prepared. These extracts were evaluated for antiseizure activity using a larval zebrafish seizure model with seizures induced by the GABA A antagonist pentylenetetrazole (PTZ). The hexane extract demonstrated the highest antiseizure activity and was therefore selected for bioassay-guided fractionation. The isolated bioactive compounds were characterized by classical spectroscopic methods. Since they were found to be volatile, they were quantified by GC-FID. In addition, the absorption of the active compounds through the gastrointestinal tract and the blood-brain barrier was evaluated using a hexadecane and a blood-brain barrier parallel artificial membrane permeability assays (HDM-PAMPA and PAMPA-BBB)., Results: The hexane extract of C. articulatus exhibited the highest antiseizure activity with a reduction of 93% of PTZ-induced seizures, and was therefore subjected to bioassay-guided fractionation in order to isolate the active principles. Four sesquiterpenoids were identified as cyperotundone (1), mustakone (2), 1,2-dehydro-α-cyperone (3) and sesquichamaenol (4) and exhibited significant antiseizure activity. These volatile compounds were quantified by GC in the hexane extract, the essential oil and the simulated traditional decoction. In addition, the constituents of the hexane extract including compounds 1 and 2 were found to cross the gastrointestinal barrier and the major compound 2 crossed the blood-brain barrier as well., Conclusion: These results highlight the antiseizure activity of various sesquiterpene compounds from a hexane extract of C. articulatus dried rhizomes and support its use as a traditional treatment for epilepsy., Competing Interests: Declaration of Competing Interest The authors declared no conflicts of interest., (Copyright © 2020 Elsevier GmbH. All rights reserved.)

Many models, such as chronic mild stress, chronic stress or chronic corticosterone injections are used to induce depression associated with cognitive deficits. However, the induction period in these different models is still long and face constraints when it is short such as in the chronic mild stress done in a minimum period of 21 days. This study aimed to characterize a model of depression with early onset cognitive deficit. 14 days combined chronic injection of corticosterone followed by 2 h restraint stress using a restrainer was used to induce depression with early cognitive deficit onset. The forced swim test, sucrose test and plasma corticosterone concentration were used to assess depression-like characteristics. The Morris water maze, novel object recognition task, as well as hippocampal acetylcholinesterase activity were used to assess cognitive deficit. The combined corticosterone injection + chronic restraint stress group presented with marked depression-like behaviour and a higher plasma corticosterone concentration compared to corticosterone injection alone and restraint stress alone. It also showed an alteration in the learning process, memory deficit as well as increased acetylcholinesterase activity compared to corticosterone injection and restraint stress alone groups. These findings suggest that the combined corticosterone administration and chronic restraint stress can be used not only as an animal model for severe depression, but also for depression with early onset cognitive deficit.

Alzheimer's disease the most common form of dementia in the elderly is a neurodegenerative disease that affects 44 millions of people worldwide. The first treatments against Alzheimer's disease are acetylcholinesterase inhibitors; however, these medications are associated with many side effects. Dichrocephala integrifolia is a traditional herb widely used by indigenous population of Cameroon to treat and prevent Alzheimer's disease and for memory improvement. In this study, we evaluated the effect of the decoction prepared from leaves of D. integrifolia , on scopolamine-induced memory impairment in mice. Seven groups of six animals were used. The first two groups received distilled water for the distilled water and scopolamine groups. The four test groups received one of the four doses of the decoction of the plant (35, 87.5, 175 or 350 mg/kg p.o.) and the positive control group received tacrine (10 mg/kg), a cholinesterase inhibitor used in the treatment of Alzheimer's disease, during 10 consecutive days. Scopolamine (1 mg/kg), a cholinergic receptor blocker, administered 30 min after treatments, was used to induce memory impairment to all groups except the distilled water group on day 10 of drug treatment. The behavioral paradigms used to evaluate the effects of the treatment were the elevated plus maze for learning and memory, Y maze for spatial short-term memory, the novel object recognition for recognition memory and Morris water maze for the evaluation of spatial long-term memory. After behavioral tests, animals were sacrificed and brains of a subset were used for the assessment of some biomarkers of oxidative stress (malondialdehyde and reduced glutathione levels) and for the evaluation of the acetylcholinesterase activity. From the remaining subset brains, histopathological analysis was performed. The results of this study showed that, D. integrifolia at the doses of 87.5 and 350 mg/kg significantly ( p < 0.01) improved spatial short-term and long-term memory, by increasing the percentage of spontaneous alternation in the Y maze and reducing the escape latency in the Morris water maze. Furthermore, the results of histopathological evaluation showed that D. integrifolia attenuated the neuronal death in the hippocampus induced by scopolamine. The main finding of this work is that D. integrifolia improves learning capacities and counteracts the memory impairment induced by scopolamine. Thus, D. integrifolia can be a promising plant resource for the management of Alzheimer's disease and memory loss.

Learning and memory are the most important executive functions performed by the human brain, the loss of which is a prominent feature in dementia. Gladiolus dalenii is traditionally used to treat a number of illnesses such as epilepsy and schizophrenia in Cameroon. This study aims to investigate the anti-amnesia effect of Gladiolus dalenii in scopolamine-induced amnesia in rats and its possible antioxidant properties in this model. Morris water maze, novel object location and recognition tasks were used to assess spatial and working memory. Male rats were treated for 12 days with saline, G. dalenii or Tacrine. Experimental animals were co-treated with scopolamine once daily from day 9 to 12. Acetylcholinesterase activity was measured in the prefrontal cortex and hippocampus. Malondialdehyde and glutathione levels were measured in the hippocampus. G. dalenii reversed memory impairment induced by scopolamine in the Morris water maze, novel object location and recognition tasks. It decreased acetylcholinesterase activity in the hippocampus and prefrontal cortex. It also decreased the level of malondialdehyde and increased the level of glutathione in the hippocampus. The results of this study show that G. dalenii ameliorates the cognitive impairment induced by scopolamine, through inhibition of oxidative stress and enhancement of cholinergic neurotransmission. It can therefore be useful for treatment of conditions associated with memory dysfunction as seen in dementia., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

Aim . To assess memory improvement and neuroprotective and antioxidant effects of Mitragyna inermis ( M. inermis ) leaf decoction on the central nervous system. Methodology . Leaf decoction of M. inermis was tested on learning and memory in normal and scopolamine-induced cognitive impairment in mice using memory behavioral tests such as the Morris water maze, object recognition task, and elevated plus maze. Oxidative stress enzymes-catalase, superoxide dismutase, and the thiobarbituric acid reactive substance, a product of lipid peroxidation-were quantified. In each test, mice 18 to 25 g were divided into groups of 5. Results . The extract reversed the effects of scopolamine in mice. The extract significantly increased discrimination index in the object recognition task test and inflexion ratio in the elevated plus maze test. The times spent in target quadrant in MWM increased while the transfer latency decreased in mice treated by M. inermis at the dose of 196.5 mg/kg. The activity levels of superoxide dismutase and catalase were significantly increased, whereas the thiobarbituric acid reactive substance was significantly decreased after 8 consecutive days of treatment with M. inermis at the dose of 393 mg/kg. Conclusion . These results suggest that M. inermis leaf extract possess potential antiamnesic effects.

Ethnopharmacological Relevance: The roots of Nauclea latifolia Smith (Rubiaceae) popularly known as "koumkouma" is used in traditional Cameroonian medicine as neuropathic pain remedy and for the treatment of headache, inflammatory pain and convulsion. This study was conducted to evaluate the antinociceptive effects of the alkaloid fraction isolated from Nauclea latifolia in neuropathic pain induced by chronic constriction injury (CCI) of the sciatic nerve in rat., Materials and Methods: Bioactive-guided fractionation of the root extracts of Nauclea latifolia using the Von Frey in a rat model of neuropathic pain (Benett model), afforded a potent anti-hyperalgesic fraction IV. Further fractionation of this fraction was performed by high-performance liquid chromatography (HPLC), yielded eight sub-fractions (F1-F8) which were tested for antinociceptive effects. The alkaloid fraction (F3) collected by HPLC, exhibited potent antinociceptive effects, and the anti-allodynic and anti-hyperalgesic effects of this fraction (8, 16, 40 and 80 mg/kg) were determined using the von Frey and acetone tests respectively in a rat model of neuropathic pain. Rota-rod performance and catalepsy tests were used for the assessment of motor coordination., Results: The alkaloid fraction (80 mg/kg) administered intraperitoneally induced a completely decreased hyperalgesia 90 min post-dosing. In the acetone test, the Nauclea latifolia fraction at 80mg/kg showed its maximal anti-allodynic effects 120 min post-injection. The areas under the curve (AUC) of the anti-allodynic or anti-hyperalgesic effects produced by the alkaloid fraction at 80 mg/kg were significantly (p<0.001) greater than the AUC of effects produced by vehicle in CCI rats. The alkaloid fraction did not exhibit any significant effects on the spontaneous locomotor activity of the mice in rota-rod performance and no sign of catalepsy was observed., Conclusion: The analysis of the effects, expressed as the time course of AUC, supports the traditional use of Nauclea latifolia in neuropathic pain therapy. The pharmacological and chemical studies are continuing in order to characterize the mechanism(s) responsible for this anti-hyperalgesic and anti-allodynic action and also to identify the active substances present in the roots extracts of Nauclea latifolia., (© 2013 Elsevier Ireland Ltd. All rights reserved.)

Background: Gladiolus dalenii Van Geel (Iridaceae) has been used for the treatment of depression and psychotic disorders in African traditional medicine. The aim of this study was to assess the effect of the aqueous extract from the corm of Gladiolus dalenii and its possible mechanisms of action., Materials and Methods: We assessed the antidepressant properties of G. dalenii corm aqueous extract in mice, using the open field, forced swimming, and tail suspension tests. Spontaneous locomotor activity of mice given various doses of G. dalenii extract (per os) was determined in the open field, whereas immobility was evaluated in the other two tests., Results: Extract maximal effect was observed at 15 mg/kg, as mice displayed a marked reduction in immobility time in both the forced swimming test (80%) and the tail suspension test (66%). In further studies aimed at investigating the mechanism of action of G. dalenii extract, the latter significantly antagonized the effect of N-methyl-D-aspartate (NMDA, 75 mg/kg) at both the doses 15 mg/kg (p<0.001) and 150 mg/kg (p=0.004). A significant reduction in immobility time was also observed following treatment with combinations of a sub-effective dose of extract (7.5 mg/kg) with either the NMDA receptor antagonist D-(-)-2-amino-7-phosphonoheptanoic acid (D-AP7, 50 mg/kg, P< 0.001), the serotonin reuptake inhibitor fluoxetine (5 and 10 mg/kg, P< 0.001 and P< 0.001 respectively), and the multi-target antidepressant imipramine (5 and 10 mg/kg, P< 0.001 and P< 0.001 respectively). Moreover, neither G. dalenii extract alone nor its combinations with NMDA ligands imipramine and fluoxetine enhanced mouse spontaneous locomotor activity., Conclusion: Altogether, these results suggest that G. dalenii has antidepressant properties, probably mediated through interactions with NMDA, serotonin and/ or noradrenergic systems, and may justify its use in traditional medicine.

Background: In Cameroonian traditional medicine various extracts of Gladiolus dalenii Van Geel (Iridaceae) have been used as a cure for various ailments that include headaches, digestive problems, muscle and joint aches, and some central nervous system disorders such as epilepsy, schizophrenia and mood disorders. Owning to this background, the aim of the study was to investigate whether an aqueous macerate of the bulb of Gladiolus dalenii has any antidepressant activity focusing specifically on depression-like behaviours associated with epilepsy., Method: We used the combined administration of atropine and pilocarpine to rats as our animal model of epilepsy. The forced swim test and spontaneous locomotor activity in the open field test were the two tools used to assess the presence of depression-like behaviour in epileptic and control animals. The following depression-related parameters were determined: plasma ACTH, plasma corticosterone, adrenal gland weight and hippocampal levels of brain-derived neurotrophic factor (BDNF). The effects of Gladiolus dalenii were compared to that of fluoxetine., Results: Our results showed that we had a valid animal model of epilepsy-induced depression as all 3 measures of construct, predictive and face validity were satisfied. The data indicated that Gladiolus dalenii significantly reduced the immobility times in the forced swim test and the locomotor activity as assessed in the open field. A similar pattern was observed when the HPA axis parameters were analysed. Gladiolus dalenii significantly reduced the levels of ACTH, corticosterone, but not the adrenal gland weight. Gladiolus dalenii significantly increased the level of BDNF in the hippocampus. In all parameters measured the effects of Gladiolus dalenii were significantly greater than those of fluoxetine., Conclusion: The results show that Gladiolus dalenii has antidepressant-like properties similar to those of fluoxetine in epilepsy-associated depressive states. The antidepressant activity of Gladiolus dalenii is likely to be mediated by restoring the activity of the HPA axis and increasing the levels of BDNF in the hippocampus.

Ethnopharmacological Relevance: The leaves of Crassocephalum bauchiense have long been used in traditional Cameroonian medicine for the treatment of epilepsy, pain, inflammatory disorders, arthritis and intestinal pain., Aim of the Study: In this study, we attempted to identify the possible antinociceptive action of the aqueous extract and the alkaloid fraction prepared from the leaves of Crassocephalum baucheiense., Materials and Methods: Using acetic acid induced abdominal constrictions, formalin-, capsaisin- and glutamate-induced nociception, and hot plate assay procedures, the antinociceptive effects of the aqueous extract and the alkaloid fraction was assessed after oral administration in mice. Morphine sulfate was used as reference analgesic agent. Mice were submitted to the rota-rod task and open-field test in order to assess any non-specific muscle-relaxant or sedative effects of the extracts of Crassocephalum bauchiense. Male and female Swiss mice were used to assess acute toxicity of these extracts., Results: The aqueous extract and the alkaloid fraction of Crassocephalum bauchiense produced a significant antinociceptive effects in the acetic acid, formalin, glutamate, capsaicin and hot plate tests. These antinociceptive effects of Crassocephalum bauchiense were significantly attenuated by pretreatment with naloxone. The extracts of Crassocephalum bauchiense did not alter the locomotion of animals in the open-field or rotarod tests, which suggest a lack of a central depressant effect. The animals did not exhibit any acute toxicity to the aqueous extract and the alkaloid fraction, so it was not possible to calculate the LD(50)., Conclusion: The results confirm the popular use of Crassocephalum bauchiense as an antinociceptive, and contribute to the pharmacological knowledge of this species because it was shown that the aqueous extract and the alkaloid fraction of Crassocephalum bauchiense produced dose related antinociception in models of chemical and thermal nociception through mechanisms that involve an interaction with opioidergic pathway., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Context:  Nauclea latifolia Smith (Rubiaceae) is a small tree found in tropical areas in Africa. It is used in traditional medicine to treat malaria, epilepsy, anxiety, pain, fever, etc., Objective:  The aim of this study was to investigate the effects of Nauclea latifolia roots decoction on the peripheral and central nervous systems and its possible mechanisms of action., Materials and Methods:  The analgesic investigation was carried out against acetic acid-induced writhing, formalin-induced pain, hot-plate and tail immersion tests. The antipyretic activity was studied in Brewer's yeast-induced pyrexia in mice. Rota-rod test and bicuculline-induced hyperactivity were used for the assessment of locomotor activity., Results:  Nauclea latifolia induced hypothermia and had antipyretic effects in mice. The plant decoction produced significant antinociceptive activity in all analgesia animal models used. The antinociceptive effect exhibited by the decoction in the formalin test was reversed by the systemic administration of naloxone, N(ω)-L-nitro-arginine methyl ester or glibenclamide. In contrast, theophylline did not reverse this effect. Nauclea latifolia (antinociceptive doses) did not exhibit a significant effect on motor coordination of the mice in Rota-rod performance. Nauclea latifolia protected mice against bicuculline-induced behavioral excitation., Discussion and Conclusion:  Overall, these results demonstrate that the central and peripheral effects of Nauclea latifolia root decoction might partially or wholly be due to the stimulation of peripheric opioid receptors through the action of the nitric oxide/cyclic monophosphate guanosin/triphosphate adenosine (NO/cGMP/ATP)-sensitive- K(+) channel pathway and/or facilitation of the GABAergic transmission.

Acanthus montanus, Alchornea laxiflora, Hyptis spicigera, Microglossa pyrifolia, Piliostigma reticulatum, and Voacanga africana were evaluated with respect to anticonvulsant and sedative activity in mice using animal models (maximal electroshock (MES), N-methyl-D-aspartate (NMDA), pentylenetetrazol (PTZ), isonicotinic hydrazide acid (INH), picrotoxin (PIC), and strychnine (STR)-induced convulsions or turning behavior and diazepam-induced sleep). Acanthus montanus protected 66.6% of mice against MES-, PIC-, and STR-induced convulsions and 83.3% of mice from PTZ-induced convulsions. Alchornea laxiflora protected 75% and 87.5% of mice in the STR and NMDA tests, respectively, at a dose of 120 mg/kg. Hyptis spicigera protected 100 and 87.5% of mice against STR- and PTZ-induced convulsions, respectively, at a dose of 160 mg/kg. Microglossa pyrifolia protected 50% to 100% of mice against convulsions. Piliostigma reticulatum protected 62.5% to 100% of mice against convulsions and turning behavior. Voacanga africana protected 62.5% to 87.5% of mice against convulsions and turning behavior. All of the plants except A. laxiflora also exerted sedative activity by strongly increasing the total duration of sleep induced by diazepam.

Extracts from rhizomes of Cyperus articulatus L. (Cyperaceae) used in Africa and Amazonia to treat many diseases has been shown to possess sedative and anticonvulsant properties. The aim of this study is to determine the mechanism of action of Cyperus articulatus extracts. In Xenopus oocytes expressing receptors, using electrophysiological measurement, extracts of rhizomes of Cyperus articulatus (300 microg/ml) inhibited 50% of the EC(50) and EC(80) of glutamate (1.3 and 2.9 microM, respectively) induced inward current through hNMDAR1A/2A receptors. Extracts induced very small current through rGluR3 receptors. The largest current induced by the extract (30 mg/ml) represents 128% of the EC(100) of glutamate induced inward current, through rGluR3 receptors. The excess 28% current could be induced by aspartate and/or glutamate in the extracts. The effect on Xenopus oocytes expressing heteromeric GABA(B)R1b/R2 receptors and rectifying potassium channels (Kir3) is clear. A decoction and water extract of Cyperus articulatus induced a large inward current that represented 71 and 57% (respectively) of the EC(100) of gaba (30 microM) induced inward current. The water extract induced also a large current through rectifying potassium channels (Kir3). Part of the current induced through GABA(B) receptors could be related to rectifying potassium channels and GABA(B) site receptors. Cyperus articulatus extracts possessed components that could decrease excitation (NMDA receptor antagonists) and increase inhibition (GABA(B) receptor agonists) in the central nervous system.

The methanolic extract of rhizomes of Cyperus articulatus, a plant used in traditional medicine in Africa and Latin America for many diseases, possesses anticonvulsant activity in mice. This extract protected mice against maximal electroshock (MES)- and pentylenetetrazol (PTZ)-induced seizures. It also delayed the onset of seizures induced by isonicotinic acid hydrazide and strongly antagonized N-methyl-D-aspartate-induced turning behavior. The ED(50) for protection against seizures was 306 (154-541) mg/kg intraperitoneally (i.p.) for the PTZ test and 1005 (797-1200) mg/kg i.p. for the MES test. The ED(50) of methanolic extract against N-methyl-D-aspartate-induced turning behavior was 875 (623-1123) mg/kg i.p. C. articulatus L. methanolic extract protected 54% of mice from seizures induced by strychnine at the dose of 1000 mg/kg i.p. but had no or a moderate effect only against picrotoxin- or bicuculline-induced seizures. With these effects, the rhizome of C. articulatus L. possesses anticonvulsant properties in animals that might explain its use as a traditional medicine for epilepsy in Africa.

The decoction of the rhizome of Cyperus articulatus is empirically used in several African countries in the treatment of a wide variety of human diseases. Studies were conducted in mice in order to determine scientifically the pharmacological properties of this medicinal herb. At the same time, the qualitative chemical characterisation of the total extract showed that C. articulatus contains flavonoids, saponins, tannins, terpenes and sugars. The total extract of the rhizome of C. articulatus does not appear to possess either anaesthetic or paralysing effects. In contrast, spontaneous motor activity is significantly reduced by the extract. However, when compared to diazepam, C. articulatus does not seem to have muscle relaxant effects. When associated with sodium thiopental or diazepam, the total extract facilitates sleep induction, and increases the total sleep time without any concomitant analgesic effect. These observations suggest that the rhizome of C. articulatus has pharmacological properties similar to those of sedatives. The sedative actions probably explain at least part of the therapeutic efficiency claimed for this plant in traditional medicine.

The marshland plant Cyperus articulatus (Cyperaceae) is commonly used in traditional medicine in Africa and Latin America to treat a wide variety of human diseases ranging from headache to epilepsy. We tested the hypothesis that the purported anti-epileptic effect of this plant might be due to a functional inhibition of excitatory amino acid receptors. One or several component(s) contained in the extracts inhibited the binding of [3H]CGP39653 to the NMDA recognition site and of [3H]glycine to the strychnine-insensitive glycine site of the NMDA receptor complex from rat neocortex. Water extracts from rhizomes of Cyperus articulatus dose-dependently reduced spontaneous epileptiform discharges and NMDA-induced depolarizations in the rat cortical wedge preparation at concentrations at which AMPA-induced depolarizations were not affected. We conclude that the purported beneficial effects of Cyperus articulatus might at least partially be due to inhibition of NMDA-mediated neurotransmission.