Behavioral and anticonvulsant effects of the standardized extract of Ficus platyphylla stem bark

Ficus platyphylla alleviates seizure severity and neurobehavioral comorbidities in pentylenetetrazole-kindled rats via modulation of oxidative stress

PTZ kindling induces oxidative stress, neuronal cell degeneration, and neurobehavioral alterations in rodents that mimic neuropsychiatric comorbidities of epilepsy, which could be initiated or aggravated by some antiepileptic drugs. Here, we investigated the effects of the methanol extract of Ficus platyphylla (FP) on severity scores for seizures, neuronal cell degeneration, and neurobehavioral alterations in rats kindled with pentylenetetrazole (PTZ) and probed the involvement of oxidative stress in these ameliorative effects of FP. FP (50 and 100 mg/kg, p.o.) ameliorated seizure severity, neuronal cell degeneration, depressive behaviors, cognitive dysfunctions, and oxidative stress in rats kindled with PTZ (42.5 mg/kg, i.p.). The findings from this study give additional insights into the potential values of FP in the treatment of persistent epilepsy and major neuropsychiatric comorbidities via modulation of oxidative stress.

LC-MS and GC-MS Profiling of Different Fractions of Ficus platyphylla Stem Bark Ethanolic Extract

The exploration of medicinal plants in traditional medicine for the treatment of diseases has been practiced for long, globally, because of its cultural acceptability, availability, and affordability. This study investigated the qualitative and quantitative estimation of phytochemicals present in Ficus platyphylla stem bark as well as determined the reducing power and antioxidant property of each fraction against DPPH and NO radicals. The study further elucidated the presence of possible compounds in different fractions (methanol, ethyl acetate, petroleum ether, and chloroform) of Ficus platyphylla stem bark (FPSB) extract using GC-MS, LC-MS, and FTIR techniques. Qualitative phytochemical analysis reveals the presence of phytochemicals: saponin, flavonoids, tannins, phenols, steroids, alkaloids, and glycoside in the ethanolic extract. The LC-MS study of methanol and ethyl acetate fractions reveals the presence of thirteen and three compounds, respectively. GC-MS analysis shows the presence of trans-13-octadecenoic acid as the main compound 38.07% and cis-vaccenic acid as the least compound (0.10%) in the petroleum ether fraction. The main compound in the chloroform fraction is 12-oleanen-3-yl acetate, (3. alpha.) with a peak area percentage of 49.25% and oleic acid been the least compound with 0.07% peak area. The FTIR analysis reveals that the fractions contain compounds with hydroxyl, aromatic, methyl, methylene, methyne, long aliphatic chain, ethers, ether-oxy, peroxides, etc. The analyzed fractions reveal compounds with potential pharmacological activity in the management of pathological conditions.

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

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

Traditional medicinal plants used for treating emerging and re-emerging viral diseases in northern Nigeria

Introduction

For decades, viral diseases have been treated using medicinal plants and herbal practices in the northern part of Nigeria. Though scarcely investigated, these medicinal plants could serve as potential sources for novel antiviral drugs against emerging and remerging viral diseases. Therefore, this study is aimed at investigating the medicinal practices and plants used to treat emerging and re-emerging viral diseases including hepatitis, poliomyelitis, monkeypox, smallpox, yellow fever, Lassa fever, meningitis, and COVID-19 in some northern states; Katsina, Kebbi, Kwara and Sokoto states.

Method

Administered questionnaires and oral interviews were used to collect information on medicinal plants, method of preparation of herbal formulations, diagnosis, and treatment of viral diseases. Medicinal plants were collected, botanically identified, and assigned voucher numbers. The plant names were verified using www.theplantlist.org, www.worldfloraonline.org and the international plant names index.

Result

A total of 280 participating herbal medicine practitioners (HMPs) mentioned 131 plants belonging to 65 families. Plant parts such as roots, bark, leaf, seed, and fruit were prepared as a decoction, concoction, infusion, or ointment for oral and topical treatment of viral diseases. Moringa oleifera (75.3%), Elaeis guineensis Jacq. (80%), and Acacia nilotica (70%) were the most frequently mentioned plants in Kebbi, Kwara and Sokoto states, respectively.

Conclusion

The study revealed scarcely investigated and uninvestigated medicinal plants used to treat hepatitis, poliomyelitis, monkeypox, smallpox, yellow fever, Lassa fever, meningitis, and COVID-19. Future studies should be conducted to determine the antiviral potency and isolate novel bioactive agents from these plants against viral diseases.

New Insights Into the Anticonvulsant Effects of Essential Oil From Melissa officinalis L. (Lemon Balm)

Melissa officinalis L. is used in traditional European and Iranian folk medicines to treat a plethora of neurological diseases including epilepsy. We utilized the in vitro and in vivo models of epilepsy to probe the anticonvulsant potentials of essential oil from M. officinalis (MO) to gain insight into the scientific basis for its applications in traditional medicine for the management of convulsive disorders. MO was evaluated for effects on maximal electroshock (MES) and pentylenetetrazole (PTZ) -induced seizures in mice, on 4–aminopyridine (4-AP)-brain slice model of epilepsy and sustained repetitive firing of current clamped neurons; and its ameliorative effects were examined on seizure severity, anxiety, depression, cognitive dysfunction, oxidative stress and neuronal cell loss in PTZ-kindled rats. MO reversibly blocked spontaneous ictal-like discharges in the 4-AP-brain slice model of epilepsy and secondary spikes from sustained repetitive firing, suggesting anticonvulsant effects and voltage-gated sodium channel blockade. MO protected mice from PTZ– and MES–induced seizures and mortality, and ameliorated seizure severity, fear-avoidance, depressive-like behavior, cognitive deficits, oxidative stress and neuronal cell loss in PTZ–kindled rats. The findings warrant further study for the potential use of MO and/or its constituent(s) as adjunctive therapy for epileptic patients.

Methanol extract of Ficus platyphylla decreases cerebral ischemia induced injury in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Extracts of the stem bark of Ficus paltyphylla (FP) are used in the Nigerian traditional medicine to manage psychoses, depression, epilepsy, pain, and inflammation. Our previous studies revealed that the methanol extract of FP ameliorate body core temperature.

AIM OF THE STUDY

A number of pharmacological agents that utilize mechanisms that enhanced neuronal survival and/or neural regeneration have been developed for the treatment of stroke. Hypothermia protects the brain from damage caused by ischemia by attenuating destructive processes such as neuroinflammation, excitotoxicity, blood-brain barrier disruption, apoptosis, and free radical formation following cerebral ischemia. In the present study, we examined the neuroprotective potential of FP on permanent occlusion of the middle cerebral artery (MCAO)-induced ischemia in mice.

MATERIAL AND METHODS

C57Bl mice were subjected to MCAO. FP was administered 1 h prior to and immediately after surgery. The brains were collected 24 h later and infarct volumes were measured using immune-histochemical staining, DAPI, NeuN, synaptophysin, and NR2B were quantified.

RESULTS

Administration of FP prior to MCAO significantly reduced infarct volume, with no effect on infarct volume immediately after MCAO. Higher numbers of cells and neurons were observed in the peri-infarct area in both groups of mice. FP-induced hypothermia protected tissue in the peri-infarct region from synaptophysin reduction. NMDA receptor 2 (NR2B) immunoreactivity is enhanced by MCAO, with no difference observed in both sham-operated and FP-induced hypothermia groups of mice.

CONCLUSIONS

The data suggest that FP might be useful in the reduction of ischemia-induced infarct volume when administered prior to the initiation of ischemia with no effect observed after ischemia induction.

An aqueous extract of Canarium schweinfurthii attenuates seizures and potentiates sleep in mice: Evidence for involvement of GABA Pathway

About 30% of epileptic patients continue to have seizures. The present study investigates the anticonvulsant and sedative effects of an aqueous extract of C. schweinfurthii in mice. Anticonvulsant effects of C. schweinfurthii aqueous extract (0.01-300 mg/kg, p.o.) were tested against 4-aminopyridine (4-AP, 15 mg/kg, i.p.) -, pilocarpine (PILO, 380 mg/kg, i.p.) - and pentylenetetrazole (PTZ, 75 mg/kg, i.p.) -induced seizures, while sedative effects were tested on diazepam (35 mg/kg, i.p.)-induced sleep. Afterward, the most effective dose of the extract (11.9 mg/kg) was antagonized with N-methyl-β-carboline-3-carboxamide or flumazenil. In another set of experiments, mice were sacrificed for the estimation of GABA content and GABA-T activity in the cerebral cortex. The dose of the extract that protected 50% of mice (ED₅₀) against 4-AP, PILO, and PTZ was respectively 4.43 mg/kg (versus 12.01 for phenobarbital), 9.59 mg/kg (vs 8.67 for diazepam), and 2.12 mg/kg (vs 0.20 for clonazepam). Further, the ED₅₀ of the extract that increased the duration of sleep was 0.24 mg/kg (vs 0.84 for phenobarbital). N-methyl-β-carboline-3-carboxamide or flumazenil antagonized (p < 0.001) the anticonvulsant effect of C. schweinfurthii in PTZ-induced seizures and diazepam-induced sleep when compared to the negative control group. The extract at all doses increased (p < 0.001) the GABA content and decreased (p < 0.001) GABA-T activity. These findings suggest that C. schweinfurthii possesses anticonvulsant and sedative effects. These effects seem to be mediated via the modulation of the GABA neurotransmission. These data explain the use of this plant to treat epilepsy in Cameroon traditional medicine.

Gamma-decanolactone attenuates acute and chronic seizures in mice: a possible role of adenosine A1 receptors

This study aimed to investigate the possible gamma-decanolactone mechanisms of action in the GABAergic and adenosine systems using the aminophylline-induced acute crisis model and the pentylenetetrazole-induced kindling model. In the acute model, male mice received administration of bicuculline (GABAA receptor antagonist), 8-cyclopentyl-1,3-dipropylxanthine (A1 receptor antagonist) or ZM241385 (A2A receptor antagonist), 15 min before the treatment with gamma-decanolactone (300 mg/kg). After a single dose of aminophylline was administered, the animals were observed for 60 min. In the chronic model of seizure, 30 min after the treatment with gamma-decanolactone, mice received pentylenetetrazole once every third day. On the last day of kindling, the animals received the same GABA and adenosine antagonists used in the acute model, 15 min before gamma-decanolactone administration. The protein expression of GABAA α1 receptor and adenosine A1 receptor was detected using western blotting technique in hippocampal samples. The results showed that gamma-decanolactone increased the latency to first seizure and decreased seizure occurrence in the acute and chronic models. The adenosine A2A receptor antagonist and GABAA receptor antagonist were not able to change gamma-decanolactone behavioral seizure induced by aminophylline or pentylenetetrazole. The administration of adenosine A1 receptor antagonist reversed the protective effect of gamma-decanolactone in both models. In addition, gamma-decanolactone promoted an increase in the expression GABAA α1 receptor, in the hippocampus. The results suggest that the neuroprotective effect of gamma-decanolactone observed during the investigation could have a straight connection to its action on A1 adenosine receptors.

Inhibition of M/Kv7 Currents Contributes to Chloroquine-Induced Itch in Mice

M/K_v7 potassium channels play a key role in regulation of neuronal excitability. Modulation of neuronal excitability of primary sensory neurons determines the itch sensation induced by a variety of itch-causing substances including chloroquine (CQ). In the present study, we demonstrate that suppression of M/K_v7 channel activity contributes to generation of itch in mice. CQ enhances excitability of the primary sensory neurons through inhibiting M/K_v7 potassium currents in a Ca²⁺ influx-dependent manner. Specific M/K_v7 channel opener retigabine (RTG) or tannic acid (TA) not only reverses the CQ-induced enhancement of neuronal excitability but also suppresses the CQ-induced itch behavior. Systemic application of RTG or TA also significantly inhibits the itch behavior induced by a variety of pruritogens. Taken together, our findings provide novel insight into the molecular basis of CQ-induced itch sensation in mammals that can be applied to the development of strategies to mitigate itch behavior.

Herbal medicine for epilepsy seizures in Asia, Africa and Latin America: A systematic review

RELEVANCE

More than 70 million people suffer epilepsy worldwide. Low availability of anti-epileptic drugs, side-effects and drug-resistant epilepsy affect the quality of life of persons with epilepsy in countries with a poorly developed health system. Herbal medicine is frequently used for this neurological condition.

OBJECTIVES

The main objective was to provide a detailed analysis of Herbal Medicine used for neurological conditions related with epilepsy in Asia, Africa and Latin America. More broadly, this study aims to highlight species with assessed efficacy (cross-cultural use, pharmacological effects on models of epileptic seizures) and safety (toxicological data in laboratory) information, in order to point out species of interest for further studies. A critical assessment of models used in pharmacological evaluations was done.

MATERIALS AND METHODS

The systematic search for Herbal Medicine treatments for epilepsy was performed considering all the articles published until February 2017 through three scientific databases. It was made with MeSH terms and free text defining the epilepsy seizures and plant species. We included studies carried out in Asia, Africa and Latin America. All articles reporting the use of Herbal Medicine to treat epilepsy seizures and/or their pharmacological evaluation were retained for further analysis.

RESULTS

The search yielded 1886 articles, from 30 countries. Hundred and six articles published between 1982 and 2017 were included, corresponding to a total of 497 use reports for 351 plant species belonging to 106 families. Three hundred and seventy seven use reports corresponding to 264 species in ethnopharmacological surveys and 120 evaluation reports corresponding to 107 species were noted. Twenty-nine reports, for 29 species, combined both ethnopharmacological and pharmacological evaluation. Fifty eight studies originated from Africa, 35 studies from Asia and 18 from Latin America. Highest use report was noted for rhizomes of Acorus calamus L. (12 use report in 1 country) and leaves of Bacopa monnieri (L.) Wettst. (8 use report in 2 countries). Therefore these species display the highest use convergence. Regarding pharmacological evaluation most studied species were: Leonotis leonurus (L.) R.Br. (4 evaluation reports in 1 country), Uncaria rhynchophylla (Miq.) Miq. ex Havil. (3 evaluation reports in 2 countries) and Calotropis gigantea (L.) Dryand. (3 evaluation reports in 1 country). In vivo models of chronic epilepsy were more relevant than in vitro models or chemical models inducing acute seizures for pharmacological assessment.

CONCLUSION

Species with the highest use report were not those with pharmacological evaluation. It will be pertinent to assess the pharmacological effects and safety of medicinal plants used mostly by traditional healers on predictive models of seizures.

The effects of herbal medicine on epilepsy

Traditional herbal medicine plays a significant role in the treatment of epilepsy. Though herbal medicine is widely used in antiepileptic treatment, there is a lack of robust evidence for efficacy and toxicity of most herbs. Besides, the herbal medicine should be subject to evidence-based scrutiny. In this context, we present a review to introduce the effects of herbal medicine on epilepsy. However, hundreds of herbal medicines have been investigated in the available studies. Some commonly used herbal medicines for epilepsy have been listed in our study. The overwhelming majority of these data are based on animal experiments. The lack of clinical data places constraints on the clinical recommendation of herbal medicine. Our study may conduct further studies and provide some insight on the development of anti-epileptic drugs.

Preclinical to Clinical Translation of Studies of Transcranial Direct-Current Stimulation in the Treatment of Epilepsy: A Systematic Review

Epilepsy is a chronic brain syndrome characterized by recurrent seizures resulting from excessive neuronal discharges. Despite the development of various new antiepileptic drugs, many patients are refractory to treatment and report side effects. Non-invasive methods of brain stimulation, such as transcranial direct current stimulation (tDCS), have been tested as alternative approaches to directly modulate the excitability of epileptogenic neural circuits. Although some pilot and initial clinical studies have shown positive results, there is still uncertainty regarding the next steps of investigation in this field. Therefore, we reviewed preclinical and clinical studies using the following framework: (1) preclinical studies that have been successfully translated to clinical studies, (2) preclinical studies that have failed to be translated to clinical studies, and (3) clinical findings that were not previously tested in preclinical studies. We searched PubMed, Web of Science, Embase, and SciELO (2002–2017) using the keywords “tDCS,” “epilepsy,” “clinical trials,” and “animal models.” Our initial search resulted in 64 articles. After applying inclusion and exclusion criteria, we screened 17 full-text articles to extract findings about the efficacy of tDCS, with respect to the therapeutic framework used and the resulting reduction in seizures and epileptiform patterns. We found that few preclinical findings have been translated into clinical research (number of sessions and effects on seizure frequency) and that most findings have not been tested clinically (effects of tDCS on status epilepticus and absence epilepsy, neuroprotective effects in the hippocampus, and combined use with specific medications). Finally, considering that clinical studies on tDCS have been conducted for several epileptic syndromes, most were not previously tested in preclinical studies (Rasmussen's encephalitis, drug resistant epilepsy, and hippocampal sclerosis-induced epilepsy). Overall, most studies report positive findings. However, it is important to underscore that a successful preclinical study may not indicate success in a clinical study, considering the differences highlighted herein. Although most studies report significant findings, there are still important insights from preclinical work that must be tested clinically. Understanding these factors may improve the evidence for the potential use of this technique as a clinical tool in the treatment of epilepsy.

Antiepileptic activity of total triterpenes isolated from Poria cocos is mediated by suppression of aspartic and glutamic acids in the brain

CONTEXT

Triterpenes from Poria cocos Wolf (Polyporaceae) have been used to treat various diseases in traditional Chinese medicine. However, the antiepileptic effects and mechanism are not fully understood.

OBJECTIVE

The objective of this study is to investigate the antiepileptic properties of total triterpenes (TTP) from the whole P. cocos.

MATERIALS AND METHODS

The ethanol extract TTP was identified by HPLC fingerprint analysis. Male ICR mice were gavaged (i.g.) with TTP (5, 20, 80 or 160 mg/kg) or reference drugs twice a day for 7 d. Antiepileptic activities of TTP were evaluated by maximal electroshock (MES)- and pentylenetetrazole (PTZ)-induced seizures in mice for 30 and 60 min, respectively. Locomotor activity and Rota-rod tests were performed for 60 min and 5 min, respectively. The levels of glutamic acid (Glu), aspartic acid (Asp), γ-aminobutyric acid (GABA) and glycine (Gly) in convulsive mice were estimated. The chronic epileptic model of Wistar rats was built to measure expressions of glutamate decarboxylase 65 (GAD65) and GABA_A in rat brain after TTP treatment.

RESULTS

The LC₅₀ of TTP (i.g.) was above 6 g/kg. TTP (5-160 mg/kg) protected mice against MES- and PTZ-induced convulsions at 65.0% and 62.5%, respectively, but have no effect on rota-rod treadmill; TTP (20-160 mg/kg) significantly reduced the locomotor activities, shortened the onset of pentobarbital sodium-induced sleep; TTP decreased Glu and Asp levels in convulsive mice, but increased the GAD65 and GABA_A expressions in chronic epileptic rats at doses usage.

DISCUSSION AND CONCLUSION

TTP extracted from P. cocos possessed potential antiepileptic properties and is a candidate for further antiepileptic drug development.

Behavioral and genotoxic evaluation of rosmarinic and caffeic acid in acute seizure models induced by pentylenetetrazole and pilocarpine in mice

The goal of this study was to investigate the effects of rosmarinic acid (RA) and caffeic acid (CA) in the acute pentylenetetrazole (PTZ) and pilocarpine (PIL) seizure models. We also evaluated the effect of RA and CA on the diazepam (DZP)-induced sleeping time test and its possible neuroprotective effect against the genotoxic damage induced by PTZ and PIL. Mice were treated intraperitoneally (i.p.) with saline, RA (2 or 4 mg/kg), or CA (4 or 8 mg/kg) alone or associated to low-dose DZP. After, mice received a single dose of PTZ (88 mg/kg) or PIL (250 mg/kg) and were monitored for the percentage of seizures and the latency to first seizure (LFS) >3 s. Vigabatrin and DZP were used as positive controls. In the DZP-induced sleeping time test, mice were treated with RA and CA and 30 min after receiving DZP (25 mg/kg, i.p.). The alkaline comet assay was performed after acute seizure tests to evaluate the antigenotoxic profiles of RA and CA. The doses of RA and CA tested alone did not reduce the occurrence of seizures induced by PTZ or PIL. The association of 4 mg/kg RA + low-dose DZP was shown to increase LFS in the PTZ model, compared to the group that received only the DZP. In the DZP-induced sleeping time test, the latency to sleep was reduced by 4 mg/kg RA and 8 mg/kg CA. The PTZ-induced genotoxic damage was not prevented by RA or CA, but the PIL-induced genotoxic damage was decreased by pretreatment with 4 mg/kg RA (in cortex) and 4 mg/kg CA (in hippocampus). In conclusion, RA and CA presented neuroprotective effect against PIL-induced genotoxic damage and reduced the latency to DZP-induced sleep. Of the rosmarinic acid, 4 mg/kg enhanced the DZP effect in the increase of latency to clonic PTZ-induced seizures.

Gan-Dan-Liang-Yi-Tang alleviates p-chlorophenylalanine-induced insomnia through modification of the serotonergic and immune system

Gan-Dan-Liang-Yi-Tang (GDLYT) is a Traditional Chinese Medicine that has been historically used for the treatment of insomnia. However, investigations into its pharmacological ingredients and the mechanism underlying its sedative and hypnotic effects remain limited. The present study reported the detailed mechanisms underlying the sedative and hypnotic effects of GDLYT. Kunming mice were administered GDLYT at various sub-hypnotic doses, which underwent sodium pentobarbital treatment test, pentetrazole induced convulsant studies and p-chlorophenylalanine (PCPA) induced insomnia model. Potentiated hypnotic and sedative effects in mice was studied, and also the changes in related neurotransmitter and immune factors were evaluated. The results suggested that GDLYT possessed weak sedative effects on pentetrazole-induced convulsive activity in normal mice at a dose of 1.3 mg/kg, with an increase in sleep onset in subhypnotic dose of sodium pentobarbital-treated mice. GDLYT was also able to alleviate insomnia induced by PCPA in the rodent models, and increased 5-hydroxytryptamine levels in the prefrontal cortex, hippocampus, hypothalamus and corpus striatum of PCPA-treated rats. Furthermore, the hypnotic effects of GDLYT were modified, which allowed for PCPA-induced immune system changes, including increased interleukin (IL)-1β, tumor necrosis factor-α and IL-2 expression levels. The results of the present study indicated that GDLYT induced sedative and hypnotic bioactivity by regulating serotonergic activity in the central nervous system and immune system.

Analgesic potential of standardized methanol stem bark extract of Ficus platyphylla in mice: Mechanisms of action

ETHNOPHARMACOLOGICAL RELEVANCE

Extracts of the stem bark of Ficus platyphylla (FP) have been used in traditional the Nigerian medicine to treat psychoses, depression, epilepsy, pain and inflammation. Previous studies have revealed the analgesic and anti-inflammatory effects of FP in different assays including acetic acid-induced writhing, formalin-induced nociception, and albumin-induced oedema.

PURPOSE/METHODS

In this study, we assessed the effects of the standardised extract of FP on hot plate nociceptive threshold and vocalisation threshold in response to electrical stimulation of the tail root in order to confirm its acclaimed analgesic properties. We also investigated the molecular mechanisms underlying these effects, with the focus on opiate receptor binding and the key enzymes of eicosanoid biosynthesis, namely cyclooxygenase (COX) and 5-lipoxygenase (5-LO).

RESULTS

FP (i) increased the hot plate nociceptive threshold and vocalisation threshold. The increase in hot plate nociceptive threshold was detectable over a period of 30min whereas the increase in vocalisation threshold persisted over a period of 90min. (ii) FP showed an affinity for µ opiate receptors but not for δ or κ opiate receptors, and (iii) FP inhibited the activities of COX-2 and 5-LO but not of COX-1.

CONCLUSIONS

We provided evidence supporting the use of FP in Nigerian folk medicine for the treatment of different types of pain, and identified opioid and non-opioid targets. It is interesting to note that the dual inhibition of COX-2 and 5-LO appears favourable in terms of both efficacy and side effect profile.

Psychoneuropharmacological activities and chemical composition of essential oil of fresh fruits of Piper guineense (Piperaceae) in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Piper guineense Schum & Thonn (Piperaceae) is a medicinal plant used in the Southern States of Nigeria to treat fever, mental disorders and febrile convulsions.

AIMS OF THE STUDY

This study aims at determining the chemical composition and the central nervous system (CNS) activities of the essential oil obtained from the plant׳s fresh fruits in order to rationalize its folkloric use.

MATERIALS AND METHODS

Essential oil of P. guineense (EOPG) obtained by hydrodistillation was analysed by GC/MS. EOPG (50-200mg/kg, i.p.) was evaluated for behavioural, hypothermic, sedative, muscle relaxant, anti-psychotic and anticonvulsant activities using standard procedures.

RESULTS AND DISCUSSION

Analysis of the oil reveals 44 compounds of which 30 compounds constituting 84.7% were identified. The oil was characterized by sesquiterpenoids (64.4%) while only four monoterpeneoids (21.3%) were found present in the oil. Major compounds identified were β-sesquiphellandrene (20.9%), linalool (6.1%), limonene (5.8%), Z-β-bisabolene (5.4%) and α-pinene (5.3%). The EOPG (50-200mg/kg, i.p.) caused significant (p<0.01) inhibition on rearing {F(4,20)=43}, locomotor {F(4,20)=22} activity and decreased head dips in hole board {F(4,20)=7} indicating CNS depressant effect; decreased rectal temperature {F(4,20)=7-16}, signifying hypothermic activity; decreased ketamine-induced sleep latency {F(4,20)=7.8} and prolonged total sleeping time {F(4,20)=8.8}, indicating sedative effect; reduced muscular tone on the hind-limb grip test {F(4,20)=22}, inclined board {F(4,20)=4-49} and rota rod {F(4,20)=13-106}, implying muscle relaxant activity; induced catalepsy {F(4,20)=47-136}, inhibited apomorphine-induced climbing behaviour {F(4,20)=9} and inhibited apomorphine-induced locomotor {F(4,20)=16}, suggesting anti-psychotic effect; and protected mice against pentylenetetrazole-induced convulsions, indicating anticonvulsant potential.

CONCLUSION

The most abundant component of the fresh fruits essential oil of P. guineense was β-sesquiphellandrene (20.9%); and the oil possesses CNS depressant, hypothermic, sedative, muscle relaxant, antipsychotic and anticonvulsant activities, thus providing scientific basis for its ethnomedicinal applications.

Methanol extract of Ficus platyphylla ameliorates seizure severity, cognitive deficit and neuronal cell loss in pentylenetetrazole-kindled mice

Decoctions of Ficus plathyphylla are used in Nigeria's folk medicine to manage epilepsy for many years and their efficacies are widely acclaimed among the rural communities of Northern Nigeria. In this study, we examined the ameliorative effects of the standardized methanol extract of Ficus platyphylla (FP) stem bark on seizure severity, cognitive deficit and neuronal cell loss in pentylenetetrazole-kindled mice. The (35)S-GTPγS, glutamate and γ-aminobutyric acid receptors binding properties of the extract were also evaluated. Male CD-1 mice were kindled with an initial subeffective dose of pentylenetetrazole (PTZ, 37.5mg/kg, i.p.) for a total of 13 convulsant injections and the treatment groups concurrently received FP (100 and 200mg/kg). Control animals received the same number of saline injections. Twenty-four h after kindling completion the animals' learning performance was tested in a two-way shuttle-box. The animals were challenged with another subeffective dose of PTZ (32.5mg/kg, i.p.) on day 7 after kindling completion. Animals were sacrificed a day after the challenged experiment and the brains were processed for histological investigation. FP ameliorates seizure severity, cognitive deficits and neuronal cell loss in PTZ kindled mice. Components of the extract showed affinity for GABAergic and glutamatergic receptors. Glutamate release was diminished and the (35)S-GTPγS binding assay revealed no intrinsic activity at glutamatergic receptors. Our results revealed that FP contains psychoactive secondary metabolites with anticonvulsant properties, thus supporting the isolation and development of the biologically active components of this medicinal plant as antiepileptic agents.

Evaluation of antinociceptive and anti-inflammatory activities of standardised rootbark extract of Xeromphis nilotica

ETHNOPHARMACOLOGICAL RELEVANCE

Xeromphis nilotica (Stapf) Keay (Rubiaceae), popularly known as 'barbaji' (in Nigeria), is a lowland shrub that grows wild in tropical areas of Africa and Asia. The plant׳s extract is used for the treatment of various diseases in folk medicine including pain related ailments. Important bioactive constituents have been isolated from the plant among them are coumarin, alkaloids, flavonoids, saponins, and terpenes. This study is aimed to evaluate the analgesic and anti-inflammatory efficacy of standardised aqueous extract of the plant using in vivo models of pain and inflammation in mice and rats.

MATERIALS AND METHODS

Aqueous extract of Xeromphis nilotica root bark was prepared and standardised using HPLC technique. Three dose levels (25, 100 and 400mg/kg) of the extract were used, administered orally to laboratory mice and rats. Acetylsalicylic acid (100mg/kg, p.o.) was used as the positive control. Nociception was induced in laboratory rodents: chemically using acetic acid and formalin, and mechanically using analgesy meter; while inflammation was induced using fresh raw egg albumin.

RESULTS

The extract showed 11 constituents peak profiles in the HPLC analysis. The extract alleviates mice response to acetic acid-induced writhing, analgesy-meter and formalin tests. It significantly decreased the oedema induced by egg albumin induced inflammation, but failed to show significant effect beyond 80min of the test.

CONCLUSION

The extract has antinociceptive effect and short acting anti-inflammatory activities. The results justify its usage in the treatment of pain and inflammatory conditions, and also provided evidence of its potential as source of new pain relief drug prototype.