Sedative and anticonvulsant activities of the aqueous root extract of Sanseviera liberica Gerome & Labroy (Agavaceae)

The central nervous system (CNS) depressant and anticonvulsant activities of the aqueous root extract of Sanseviera liberica (ASL) were investigated on various animal models including pentobarbitone sleeping time and hole-board exploratory behaviour for sedation tests, and strychnine, picrotoxin, bicuculline and pentylenetetrazole-induced convulsions in mice. ASL (100-400mg/kg, p.o.), like chlorpromazine HCl (1mg/kg, i.m.), produced a dose-dependent prolongation of pentobarbitone sleeping time and suppression of exploratory behaviour. ASL (100 and 200mg/kg) produced dose-dependent and significant (P<0.05) increases in onset to clonic and tonic convulsions, and at 400mg/kg, showed complete protection against seizures induced by strychnine, picrotoxin and bicuculline, but not with pentylenetetrazole. ASL up to 10 g/kg, p.o. did not produce death, but i.p. treatment produced mortalities with LD(50) of 668.3+/-47.6 mg/kg. Preliminary phytochemical investigations of ASL revealed the presence of carbohydrates, alkaloids, saponins, reducing sugars and oils. The results indicate that ASL has sedative and anticonvulsant activities, therefore, justifying its use in traditional African medicine.     

Anticonvulsant effect of Persea americana Mill (Lauraceae) (Avocado) leaf aqueous extract in mice

Various morphological parts of Persea americana Mill (Lauraceae) (avocado) are widely used in African traditional medicines for the treatment, management and/or control of a variety of human ailments, including childhood convulsions and epilepsy. This study examined the anticonvulsant effect of the plant's leaf aqueous extract (PAE, 50-800 mg/kg i.p.) against pentylenetetrazole (PTZ)-, picrotoxin (PCT)- and bicuculline (BCL)-induced seizures in mice. Phenobarbitone and diazepam were used as reference anticonvulsant drugs for comparison. Like the reference anticonvulsant agents used, Persea americana leaf aqueous extract (PAE, 100-800 mg/kg i.p.) significantly (p < 0.05-0.001) delayed the onset of, and antagonized, pentylenetetrazole (PTZ)-induced seizures. The plant's leaf extract (PAE, 100-800 mg/kg i.p.) also profoundly antagonized picrotoxin (PCT)-induced seizures, but only weakly antagonized bicuculline (BCL)-induced seizures. Although the data obtained in the present study do not provide conclusive evidence, it would appear that 'avocado' leaf aqueous extract (PAE) produces its anticonvulsant effect by enhancing GABAergic neurotransmission and/or action in the brain. The findings of this study indicate that Persea americana leaf aqueous extract possesses an anticonvulsant property, and thus lends pharmacological credence to the suggested ethnomedical uses of the plant in the management of childhood convulsions and epilepsy.     

Anticonvulsant effect of Rhus chirindensis (Baker F.) (Anacardiaceae) stem-bark aqueous extract in mice

Extracts of Rhus chirindensis stem-bark are used extensively in South African traditional medicines for the treatment, management and/or control of an array of human ailments, including childhood convulsions and epilepsy. In this study, we investigated the anticonvulsant activity of the plant's stem-bark aqueous extract (RCE, 50-800 mg/kg i.p.) against pentylenetetrazole (PTZ)-, picrotoxin (PCT)- and bicuculline (BCL)-induced seizures in mice. Phenobarbitone and diazepam were used as reference anticonvulsant drugs for comparison. Single intraperitoneal injections of PTZ (90 mg/kg), PCT(10 mg/kg) or BCL (30 mg/kg) produced tonic-clonic seizures. Like the standard antiseizure drugs used, Rhus chirindensis stem-bark aqueous extract (RCE, 100-800 mg/kg i.p.) significantly delayed (p<0.05-0.001) the onset of, and antagonized pentylenetetrazole-induced seizures. The plant's stem-bark aqueous extract (RCE, 100-800 mg/kg i.p.) also profoundly antagonized picrotoxin-induced seizures, but only weakly antagonized bicuculline-induced seizures. Although the data obtained in the present study do not provide conclusive evidence, it would appear that RCE produces its antiseizure effect by enhancing GABAergic neurotransmission and/or action in the brain. The results of this laboratory animal study indicate that RCE possesses anticonvulsant activity in the mammalian experimental model used, and thus suggest that the plant may be used as a natural supplementary remedy in the management, control and/or treatment of childhood convulsions and epilepsy. In conclusion, the findings of this study lend pharmacological credence to the suggested folkloric, ethnomedical uses of Rhus chirindensis in the management of childhood convulsions and epilepsy in some rural communities of South Africa.     

Anticonvulsant activity of Hypoxis hemerocallidea Fisch. & C. A. Mey. (Hypoxidaceae) corm ('African potato') aqueous extract in mice

Extracts of Hypoxis hemerocallidea Fisch. & C. A. Mey. (Hypoxidaceae) corm (popularly known as 'African potato') are extensively used in South African traditional medicines for the treatment, management and/or control of an array of human ailments, including childhood convulsions and epilepsy. This study examined the anticonvulsant activity of the plant's corm aqueous extract (APE, 50-800 mg/kg i.p.) against pentylenetetrazole (PTZ)-, picrotoxin (PCT)- and bicuculline (BCL)-induced seizures in mice. Phenobarbitone and diazepam were used as reference anticonvulsant drugs for comparison. Like the reference antiseizure drugs used, Hypoxis hemerocallidea corm aqueous extract (APE, 100-800 mg/kg i.p.) significantly delayed (p < 0.05-0.001) the onset of, and antagonized, pentylenetetrazole (PTZ)-induced seizures. The plant's corm aqueous extract (APE, 100-800 mg/kg i.p.) also profoundly antagonized picrotoxin (PCT)-induced seizures, but only weakly antagonized bicuculline (BCL)-induced seizures. Although the data obtained in the present study do not provide conclusive evidence, it would appear that 'African potato' aqueous extract (APE) produces its antiseizure effect by enhancing GABAergic neurotransmission and/or action in the brain. The results of this laboratory animal study indicate that APE possesses anticonvulsant activity in the mammalian experimental model used and, therefore, tend to suggest that the herb may be used as a natural supplementary remedy in the management, control and/or treatment of childhood convulsions and epilepsy. In conclusion, the findings of this study indicate that Hypoxis hemerocallidea corm aqueous extract possesses anticonvulsant activity, and thus lend pharmacological credence to the suggested folkloric, anecdotal ethnomedical uses of the herb in the management of childhood convulsions and epilepsy in some rural communities of South Africa.     

Analgesic and anticonvulsant properties of Tetrapleura tetraptera (Taub) (Fabaceae) fruit aqueous extract in mice

Previous studies in our laboratories and elsewhere have shown that the fruit of Tetrapleura tetraptera (Taub) (family: Fabaceae) is widely used in African traditional medicine for the management and/or control of an array of human ailments, including schistosomiasis, asthma, epilepsy, hypertension and so on. The present study was designed to investigate the analgesic and anticonvulsant effects of Tetrapleura tetraptera (Taub) fruit aqueous extract (TTE) in mice. Morphine (MPN, 10 mg/kg i.p.), diclofenac (DIC, 100 mg/kg i.p.), phenobarbitone (20 mg/kg i.p.) and diazepam (0.5 mg/kg i.p.) were used, respectively, as reference analgesic and anticonvulsant agents for comparison. T. tetraptera fruit aqueous extract (TTE, 50-800 mg/kg i.p.) produced dose-dependent, significant (p < 0.05-0.001) analgesic effects against thermally and chemically induced pain in mice. Like the standard anticonvulsant agents (phenobarbitone and diazepam) used, T. tetraptera fruit aqueous extract (TTE, 50-800 mg/kg i.p.) significantly (p < 0.05-0.001) delayed the onset of, and antagonized, pentylenetetrazole (PTZ)-induced seizures. Aqueous extract of the fruit (TTE, 50-800 mg/kg i.p.) also profoundly antagonized picrotoxin (PCT)-induced seizures, but only partially and weakly antagonized bicuculline (BCL)-induced seizures. However, the results of this experimental animal study indicate that Tetrapleura tetraptera (Taub) fruit aqueous extract (TTE) possesses analgesic and anticonvulsant properties. These findings lend pharmacological support to the suggested folkloric uses of the plant's fruit in the management and/or control of painful, arthritic inflammatory conditions, as well as for the management and/or control of epilepsy and childhood convulsions in some tropical African countries.     

Anticonvulsant activities of the FS-1 subfraction isolated from roots of Delphinium denudatum

Delphinium denudatum Wall. (Ranunculaceae) is a medicinal herb used for the treatment of epilepsy in the subcontinent. The present study reports the anticonvulsant activities in the maximal electroshock test (MEST) and subcutaneous pentylenetetrazole (PTZ), bicuculline (BIC), picrotoxin (PIC)-induced seizures of the FS-1 subfraction (FS-1) that was obtained by purification of an aqueous fraction isolated from the roots of D. denudatum. In CF 1 mice, FS-1 (600 mg/kg i.p.) exhibited very potent anticonvulsant activity that was comparable to the effects of the well-known antiepileptic drug phenytoin (20 mg/kg) in MEST and protected 100% animals from hind limb tonic extension phase of this model. FS-1 also suppressed PTZ-induced threshold seizure and the loss of the righting reflex with tonic fore and hind limb extension by 100%, similar to the antiepileptic drug valproic acid (350 mg/kg). BIC-induced seizures were suppressed in 80% of the animals. FS-1 exhibited weak anticonvulsant effect on PIC-induced seizures, however, it significantly reduced mortality and delayed the onset of seizures. FS-1 had no effect on strychnine (STN)-induced extensor seizures. The results demonstrate the broad and potent anticonvulsant activity of the compounds in FS-1 of D. denudatum.     

CNS inhibitory effects of barakol,a constituent of Cassia siamia Lamk

The present study determined the pharmacological profile of barakol, a major constituent of Cassia siamea Lamk., in rodent behavioral and neurochemical tests. Barakol reduced spontaneous locomotor activity, increased the number of sleeping animals and prolonged the thiopental-induced sleeping time, indicating a sedative effect. As for interactions between barakol and convulsants (pentylenetetrazole (PTZ), picrotoxin, bicuculline and strychnine), only a high dose (100 mg/kg, i.p.) of barakol slightly prolonged the latency of clonic convulsion induced by picrotoxin. This suggests that the sedative effect may not be induced via the GABA or glycine systems. There was no evidence of an anxiolytic effect of barakol in the plus-maze test. However, barakol (25-100 mg/kg, i.p.) could suppress methamphetamine (1 mg/kg, i.p.)-induced hyper-locomotor activity in a dose-dependent manner, indicating an effect on the dopaminergic system. In a microdialysis study, the dose of barakol (100 mg/kg) that inhibited spontaneous locomotor activity in mice did not affect the basal levels of extracellular dopamine (DA) or its metabolites in the striatum. However, pretreatment with barakol (100 mg/kg, i.p.) decreased the maximal dopamine release and dopamine turnover induced by methamphetamine (1 mg/kg, i.p.). This finding indicates that the inhibitory effect of barakol on dopamine release may account for the blocking effect of barakol on the striatum-related behavior induced by methamphetamine.     

The effects of Icacina trichantha tuber extract on the nervous system

The tuber of Icacina trichantha was extracted with 50% methanol and concentrated to dryness in vacuo to give a yield of 5.6% w/w. The extract induced sleep in rats treated with high doses (400–1000 mg/kg i.p.). The LD₅₀ of the extract was 671 mg/kg i.p. It potentiated pentobarbitone sleeping time in rats dose-dependently and also induced significant local anaesthetic effects in guinea-pigs. The extract was able to give 80% protection to rats poisoned with pentylenetetrazole but failed to protect rats from strychinine poisoning. It induced significant dose-dependent analgesia in rats and showed significant muscle relaxant activity in mice.     

Anticonvulsant activity of the methanolic extract of Justicia extensa T. Anders

Ethnopharmacological relevance

To investigate the anticonvulsant activity of the leaf extract of Justicia extensa T. Anders used traditionally in the treatment of convulsion.

Materials and methods

The anticonvulsant activity of the methanolic extract of Justicia extensa (50, 100 and 200 mg/kg, p.o.) was assessed in strychnine-induced (STR) and picrotoxin-induced (PCT) convulsion models in mice. Diazepam (1 mg/kg) and phenobarbitone (2 mg/kg) were used as reference drugs respectively.

Results

The extract showed no toxicity and significantly prolonged (p < 0.01-0.05) the onset and reduced the duration of the seizures induced by picrotoxin (5 mg/kg, i.p.) in a dose dependent manner. Phenobarbitone completely inhibited the seizures in this model. Similarly, in the seizures induced by strychnine (1 mg/kg, i.p.), the extract also prolonged the onset and reduced the duration of the seizures though not in a dose dependent manner. Diazepam failed to inhibit the strychnine-induced seizures. The plant extract however showed a significantly higher anticonvulsant activity at 100 and 200 mg/kg in comparison with diazepam.

Conclusions

The results obtained from this work suggest that Justicia extensa has anticonvulsant activity and this supports the use of the plant traditionally in the treatment of convulsion.     

Anticonvulsant activities of nutmeg oil of Myristica fragrans

The purpose of this study was to investigate the anticonvulsant activity of the volatile oil of nutmeg, the dried seed kernel of Myristica fragrans Houtt, using well‐established animal seizure models and to evaluate its potential for acute toxicity and acute neurotoxicity. The volatile oil of nutmeg (nutmeg oil) was tested for its effects in maximal electroshock, subcutaneous pentylenetetrazole, strychnine and bicuculline seizure tests. All the experiments were performed at the time of peak effect of nutmeg oil. Nutmeg oil showed a rapid onset of action and short duration of anticonvulsant effect. It was found to possess significant anticonvulsant activity against electroshock‐induced hind limb tonic extension. It exhibited dose dependent anticonvulsant activity against pentylenetetrazole‐induced tonic seizures. It delayed the onset of hind limb tonic extensor jerks induced by strychnine. It was anticonvulsant at lower doses, whereas weak proconvulsant at a higher dose against pentylenetetrazole and bicuculline induced clonic seizures. Nutmeg oil was found to possess wide therapeutic margin, as it did not induce motor impairment when tested up to 600 µL/kg in the inverted screen acute neurotoxicity test. Furthermore, the LD₅₀ (2150 µL/kg) value was much higher than its anticonvulsant doses (50–300 µL/kg). The results indicate that nutmeg oil may be effective against grand mal and partial seizures, as it prevents seizure spread in a set of established animal models. Slight potentiation of clonic seizure activity limits its use for the treatment of myoclonic and absence seizures. Copyright © 2008 John Wiley & Sons, Ltd.     

Anticonvulsant effect of Ficus religiosa: Role of serotonergic pathways

Ethnopharmacological relevance

Ficus religiosa (Moraceae) is reported to have numerous therapeutic utility in folk medicine. Among different biological activities on central nervous system, it has been reported to be used in ethnomedical treatment of epilepsy, which led us to further explore its anticonvulsant activity in various animal models of epilepsy.

Aim of the study

To investigate anticonvulsant activity of methanolic extract of figs of Ficus religiosa in animal models and to determine its possible anticonvulsant mechanism.

Materials and methods

Anticonvulsant activity of figs extract (25, 50 and 100 mg/kg, i.p.) was studied in seizures induced by maximum electroshock (MES), picrotoxin and pentylenetetrazol (PTZ). Cyproheptadine, a nonselective (5HT_1/2) serotonin antagonist (4 mg/kg, i.p.) was used to study the reversal of protective effect of extract in the above mentioned models. Acute toxicity, neurotoxicity and potentiation of pentobarbitone induced sleep by extract was also studied.

Results

Extract showed no toxicity, potentiated pentobarbitone induced sleep and inhibited seizures induced by MES and picrotoxin in a dose dependent manner. Anticonvulsant effect of extract was comparable to clinically used antiepileptic drugs (phenytoin and diazepam). However, PTZ induced seizures were not inhibited. Animals pretreated with cyproheptadine showed inhibition of the anticonvulsant effect of extract.

Conclusions

These findings suggested that the methanolic extract of figs of Ficus religiosa had anticonvulsant activity against MES and picrotoxin induced convulsions, with no neurotoxic effect, in a dose dependent manner. Inhibition of the anticonvulsant effect of extract by cyproheptadine substantiates the involvement of serotonergic pathways for the anticonvulsant activity of extract.     

Antimicrobial and anticonvulsant activities of Viscum capense

Dichloromethane, methanol and water extracts of Viscum sapense L.f., of the Loranthaceae family, were tested for antimicrobial activities against Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans. Methanol extract was also tested for activity against seizures in albino mice induced by pentylenetetrazole (PTZ), bicuculline and N-methyl-dl-aspartic acid (NMDLA). Methanol extract of V. capense inhibited the growth of S. aureus. Methanol extract also protected the mice against PTZ- and bicuculline-induced tonic seizures but did not significantly alter NMDLA-induced tonic seizures. The data indicate that the extract of V. capense has antibacterial activity against S. aureus and also anticonvulsant activity.     

Antinociceptive and anti-inflammatory effects of Thespesia populnea bark extract

The ethanolic extract of Thespesia populnea bark (TPE) was investigated for anti-inflammatory and analgesic activity at the doses (p.o.) of 100, 200 and 400mg/kg body weight. For evaluation of inflammation carrageenan-, histamine- and serotonin-induced paw edema served as acute models and formaldehyde-induced arthritis served as a chronic model in rats. The acetic acid-induced writhing response and formalin-induced paw licking time in the early and late phases of mice were used to assess analgesic activity. The higher doses of TPE (200 and 400mg/kg, p.o.) were inhibiting carrageenan, histamine and serotonin-induced paw edema as well as formaldehyde-induced arthritis successfully. In addition, TPE (200 and 400mg/kg, p.o.) significantly attenuated the writhing responses induced by an intraperitoneal injection of acetic acid and late phase of pain response induced by an subplantar injection of formalin in mice. Furthermore, our phytochemical studies indicated that the ethanolic extract of bark contains alkaloids, carbohydrates, protein, tannins, phenols, flavonoids, gums and mucilage, saponins and terpenes. From acute oral toxicity studies (OECD-423 guidelines), no mortality was observed even at highest dose of TPE (2000mg/kg, p.o.).     

Anticonvulsant activity of DNS II fraction in the acute seizure models

Aim of the study

Delphinium nordhagenii belongs to family Ranunculaceae, it is widely found in tropical areas of Pakistan. Other species of Delphinium are reported as anticonvulsant and are traditionally used in the treatment of epilepsy. Delphinium nordhagenii is used by local healer in Pakistan but never used for scientific investigation as anticonvulsant. Thus, Delphinium nordhagenii was subjected to bioassay-guided fractionation and the most active fraction, i.e. DNS II acetone was chosen for further testing in the acute seizure models of epilepsy to study the antiepileptic potential in male mice.

Materials and methods

Different doses (60, 65 and 70 mg/kg, i.p.) of DNS II acetone fraction of Delphinium nordhagenii was administered 30 min prior the chemoconvulsant's injection in the male mice. Convulsive doses of chemoconvulsants (pentylenetetrazole 90 mg/kg, s.c. and picrotoxin 3.15 mg/kg, s.c.) were used. The mice were observed 45–90 min for the presence of seizures. Moreover, four different doses of DNS II (60, 65, 70 and 100 mg/kg, i.p.) were tested in the MES test.

Results

The DNS II acetone fraction of Delphinium nordhagenii has exhibited the anticonvulsant actions by preventing the seizures against PTZ- and picrotoxin-induced seizure as well as 100% seizure protection in MES test. The results are comparable with standard AEDs (diazepam 7.5 mg/kg, i.p. and phenytoin 20 mg/kg, i.p.).

Conclusions

These findings suggest that the Delphinium nordhagenii possesses the anticonvulsant activity. Further analysis is needed to confirm the structure and target the extended activity profile.     

Anticonvulsant properties of the methanolic extract of Cyperus articulatus (Cyperaceae)

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.     

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

Ethnopharmacological relevance

Decoctions of Ficus platyphylla Del.-Holl (Family: Moraceae) are used in Nigeria?s folk medicine for the management of epilepsy and their efficacies are widely acclaimed among the rural communities of northern Nigeria. The aim of the study is to examine the behavioral and anticonvulsant properties of the standardized methanol extract of Ficus platyphylla (FP) stem bark, in order to scientifically describe its potential values in the management of convulsive disorders.

Materials and methods

High performance liquid chromatography (HPLC) and preliminary phytochemical analysis of the methanol extract were utilized and the intraperitoneal median lethal dose (LD₅₀) determined in mice. The effects of FP were investigated on some murine models of behavior and its anticonvulsant effects studied on pentylenetetrazole (PTZ)-, strychnine (STN)-, picrotoxin (PCT)-, isoniazid (INH)-, aminophylline (AMI)- and maximal electroshock (MES)-induced seizures in mice.

Results

The intraperitoneal oral LD₅₀ of FP was estimated to be 5000 mg/kg. FP significantly reduced the locomotor activities including the total distance covered, speed, active time and rearing counts. It shortened the onset and prolonged the duration of diazepam-induced sleep, but had no effect on motor coordination on the rota-rod treadmill or beam-walking assay in mice at the doses tested. The extract protected the mice against PTZ- and STN-induced seizures and significantly delayed the latencies of myoclonic jerks and tonic seizures induced by all the standard convulsant agents (PTZ, PCT, INH, STN and AMI) used in this study, but failed to protect the mice against MES seizures at the doses tested. The HPLC fingerprint of the extract shows a spectrum profile characteristic of Ficus platyphylla, while the preliminary phytochemical screening revealed the presence of saponins, flavonoids and tannins.

Conclusion

Our study provides scientific evidence that FP may contain psychoactive principles with potential anticonvulsant properties, thus supporting further development of the psychoactive components of this plant as anticonvulsant agents.     

Efficacy of shitei-to, a traditional Chinese medicine formulation, against convulsions in mice.

The anticonvulsant effects of Shitei-To and its components on maximal electroshock seizures and chemical convulsions were examined. Shitei-To significantly prolonged the latency to bicuculline (2.0 mg/kg, s.c.)-induced clonic convulsions. Repeated treatment with Shitei-To also significantly prolonged the latency to strychnine (1.5 mg/kg, i.p.)- and pentylenetetrazol (90 mg/kg, i.p.)-induced clonic convulsions. On the other hand, Shitei-To had no effect on maximal electroshock seizures. Of the components of Shitei-To, Shitei had almost the same effect as Shitei-To against the clonic convulsions induced by the three chemical agents tested. These findings suggest that Shitei-To has anticonvulsant effects.     

Antidiarrhoeal activity of seed extract of Albizzia lebbeck Benth

The antidiarrhoeal activity of the seed extract of Albizzia lebbeck (Benth.) was investigated employing conventional rodent models of diarrhoea, i.e. castor oil-induced diarrhoea, upper gastrointestinal transit (u.g.t.) and fluid secretion. It was found that the aqueous methanol extract of Albizzia lebbeck seeds (2.5-5 mg/kg i.p.) possessed antidiarrhoeal activity which strengthens the earlier use of the seeds in the treatment of diarrhoea and dysentery. The antidiarrhoeal dose of the extract was at least 10-30 times less than the LD(50) dose. The extract (2.5-5 mg/kg i.p.) potentiated the antidiarrhoeal activity of loperamide (1 mg/kg i.p.). Nalaxone (0.5 mg/kg i.p.) significantly inhibited the antidiarrhoeal activity of the extract as well as loperamide, thus indicating a role of the opioid system in the antidiarrhoeal activity of the extract.     

Anticonvulsant activity of the essential oil and methanolic extract of Bunium persicum (Boiss). B. Fedtsch

Ethnopharmacological relevance

Bunium persicum is an endemic plant to Iran which its seeds have a long history of medicinal uses.

Aim of the study

This work aimed to study the anticonvulsant effect of the essential oil and methanolic extract of the plant.

Materials and methods

The essential oil and methanolic extract of the plant were studied against pentylenetetrazole (PTZ) and maximal electroshock (MES) induced convulsions in mice in different doses. The neurotoxicity of the essential oil and methanolic extract was investigated using rotarod method.

Results

The essential oil and methanolic extract prolonged the onset of clonic and tonic seizures in PTZ. The tonic seizures were prevented by essential oil in both methods at dose of 1 mL/kg and higher doses. The methanolic extract inhibited PTZ-convulsions at dose 3 g/kg and was ineffective against MES induced convulsion.

Conclusions

The essential oil of the plant might be useful to control absence and grand mal seizures at dose 1 mL/kg. This activity might be due to its content of monoterpenes.     

Depressant effects of Clinopodium mexicanum Benth. Govaerts (Lamiaceae) on the central nervous system

Ethnopharmacological relevance

The decoction of leaves of Clinopodium mexicanum Benth. Goaverts (Lamiaceae), commonly known as “Toronjil de Monte”, is used in the Mexican traditional medicine to induce sleep, as well as sedative and analgesic remedy.

Aim of the study

To evaluate the putative depressant effects of an aqueous extract of the medicinal plant Clinopodium mexicanum on the central nervous system (CNS).

Materials and methods

The effects of the extract (AECM) on mice were tested in several animal paradigms, including sodium pentobarbital-induced sleep, open field tests, and hole-board tests. The effects of AECM on pentylenetetrazole- and picrotoxin-induced convulsions in mice and on the antithermonociceptive response in the hot-plate paradigm were also tested. Additionally, the active extract (AECM) was analyzed with HPLC–ESI-MS techniques.

Results

Mice acutely treated with AECM at 100, 200, 500 and 1000 mg/kg doses prolonged the sleeping time induced by sodium pentobarbital (42 mg/kg). This extract, at 100 and 200 mg/kg doses, showed a sedative effect in the hole-board paradigm and decreased spontaneous activity in mice. AECM at 10, 100 and 200 mg/kg prolonged the onset of seizures induced by pentylenetetrazole (90 mg/kg) and antagonized tonic convulsions induced by picrotoxin (10 mg/kg). Additionally, AECM inhibited the response to a thermonociceptive stimulus. The intraperitoneal AECM treatment produced mortality with an LD₅₀ = 2154 mg/kg. Chemical analysis showed that the flavanone glycosides neoponcirin, poncirin, and isonaringenin are the main compounds of the active extract.

Conclusions

This study demonstrates that an acutely administered single dose of an aqueous extract of Clinopodium mexicanum can exert depressant effects on the CNS. These findings are in agreement with the traditional use of Clinopodium mexicanum to induce sleep as well as sedative and analgesic remedy. The chemical analysis of AECM revealed the presence of the flavanone glycosides neoponcirin, poncirin, and isonaringin.