CNS depressant activity of Lecaniodiscus cupanioides

Traditional uses, biological activities, and phytochemicals of Lecaniodiscus cupanioides: a review

Medicinal plants are indispensable source of therapeutic agents, and have proved to be “warehouse” of lead drug candidates. Lecaniodiscus cupanioides Planch. ex Benth is a medicinal tree plant that is extensively distributed in both Asia and Africa. The species has many ethnomedicinal uses in the treatment of fever, cough, typhoid, wound, skin infection, measles, jaundice, diabetes, sexual dysfunction, cancer, bone fracture, and as galactogogues. In the recent decades, the extracts and phytochemicals of L. cupanioides have been investigated to possess antibacterial, anticancer, aphrodisiac, antifungal, cytotoxic, antidiabetic, antiprotozoal, antioxidant, antidiarrhoeal, analgesic and ameliorative properties. However, triterpenoids which have been linked to its anticancer and antifungal actions, are the only isolated active constituents identified from the species despite the results of the phytochemical screenings and reported biological activities. Moreover, the mechanisms of action of the extracts and active components are yet to be fully elucidated. This paper provides a general review on the ethnomedicinal, phytochemicals, and biological activities of L. cupanioides, and lays a solid foundation for future investigations on the plant.

Anti-inflammatory and analgesic potential of OA-DHZ; a novel semisynthetic derivative of dehydrozingerone

Despite various advances in the arena of the current system of medicine, there are numerous side effects associated with the therapeutics which essentially demand research on the development of safer therapeutics. One way is to explore the bioactive plant secondary metabolites and their semisynthetic derivatives. In context to this, we analyzed OA-DHZ, a dehydrozingerone derivative as the later has been reported to show anti-inflammatory and analgesic properties. OA-DHZ was found to be having promising anti-inflammatory and analgesic potential. OA-DHZ was found to inhibit the carrageenan-induced edema and leukocyte migration, acetic acid-induced increase in vascular permeability and lipopolysaccharide-induced pro-inflammatory cytokines like TNF-α, IL-6, and IL-1β. Meanwhile, it was also found to potentially inhibit thermally as well as chemically induced pain signifying its analgesic/nociceptive potential. Further, safety pharmacology studies using in vivo animal models for the central nervous system, gastrointestinal tract, the cardio-respiratory system suggest that optimum functioning of vital organ systems does not get altered after single oral administration. Also, the acute toxicity study revealed its nontoxic nature up to 2000 mg/kg. This study paves the way for future exploration and development of OA-DHZ based on its potent activity and nontoxic nature.

Evidence for the involvement of the GABA-ergic pathway in the anticonvulsant activity of the roots bark aqueous extract of Anthocleista djalonensis A. Chev. (Loganiaceae)

BACKGROUND

The root bark of Anthocleista djalonensis A. Chev. (Loganiaceae) is widely used in traditional medicine in Northern Cameroon to treat epilepsy and related conditions, such as migraine, insomnia, dementia, anxiety, and mood disorders.

METHODS

To investigate the anticonvulsant effects and the possible mechanisms of this plant, an aqueous extract of Anthocleista djalonensis (AEAD) was evaluated by using animal models of bicuculline-, picrotoxin-, pilocarpine-, and pentylenetetrazole-induced convulsions. Their effects on brain γ-aminobutyric acid (GABA) concentration and GABA-T activity were also determined.

RESULTS

This extract significantly protected mice against bicuculline-induced motor seizures. It provided 80% protection against picrotoxin-induced tonic-clonic seizures, and strongly antagonized convulsions induced by pilocarpine. AEAD also protected 100% of mice against pentylenetetrazole-induced seizures. Flumazenil, a central benzodiazepine receptor antagonist and FG7142, a partial inverse agonist in the benzodiazepine site of the GABAA receptor complex, were found to have an inhibitory effect on the anticonvulsant action of AEAD in pentylenetetrazole test. Finally, the brain GABA concentration was significantly increased and GABA-T activity was inhibited by AEAD.

CONCLUSIONS

The effects of Anthocleista djalonensis suggested the presence of anticonvulsant properties that might involve an action on benzodiazepine and/or GABA sites in the GABAA receptor complex or by modulating GABA concentration in the central nervous system (CNS).

In vivo Study on Depressant Effects and Muscle Coordination Activity of Galphimia glauca Stem Methanol Extract

BACKGROUND

Galphimia glauca is an evergreen shrub found across peninsular India, belonging to family Malpighiaceae.

OBJECTIVE

The objective of this study was to assess the in vivo depressant effects and muscle coordination activity of G. glauca stem methanol extract (GGSME).

MATERIALS AND METHODS

The stem methanol extract was administered in Swiss albino mice in 1 day to study the central nervous system (CNS) depressant and muscle coordination activity employing animal models such as sodium pentobarbital-induced sleep test, hole-board test, open field test, pentylenetetrazole (PTZ)-induced convulsions, picrotoxin-induced convulsions, grip strengthening test in mice, and Rota-rod test.

RESULTS

The LD₅₀ of GGSME was found to be >2000 mg/kg body weight (b.w.). Mice treated with stem methanol extract at 100, 200, and 400 mg/kg, b.w. doses extended the sleeping time induced by sodium pentobarbital (40 mg/kg. b.w., i.p.). The stem methanol extract at 400 mg/kg dose showed a significant (P ≤ 0.001) dose-dependent decrease in the number of rears and head dipping number in the hole-board test. The extract exhibited a significant (P ≤ 0.001) effect on the ambulatory behavior of mice in the open field test and also extended the onset of seizures induced by PTZ (90 mg/kg b.w., i.p.) and picrotoxin (10 mg/kg, b.w., i.p.). The extract also exhibited significant (P ≤ 0.001) effects on muscle coordination in rota-rod and grip strengthening test in mice.

CONCLUSION

The study results conclude that the GGSME has a potential CNS depressant and muscle relaxant effects compared to the standard drugs.

SUMMARY

Anxiety is implicated in the number of psychiatric disordersIn vivo depressant activity is studied employing animal models like Sodium pentobarbital-.induced sleep test, Hole-board test, Open field test, Pentylenetetrazole induced convulsions and Picrotoxin-induced convulsions tests.Muscle coordination activity is studied employing animal models like Grip strengthening test in mice and Rota-.rod test.The GABAergic system plays a significant role in CNS depressant and muscle relaxant effects.The study proves the traditional claims of the plant used in the treatment of phobia, panic, stress, anxiety and it is as well used in producing a calming effect on the nerves. Abbreviations Used: WHO: World Health Organization; CNS: Central nervous system; GGSME: Galphimia glauca stem methanol extract; IAEC: Institutional Animal Ethics Committee; OECD: The Organization for Economic Co-operation and Development; PTZ: Pentylenetetrazole; REM: Rapid eye movement; GABA: γ-aminobutyric acid; AMPA: α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor; b.w: Body weight; i.p: Intraperitoneal; p.o: per oral.

Aqueous root extract of Lecaniodiscus cupanioides restores nitric oxide/cyclic guanosine monophosphate pathway in sexually impaired male rats

ETHNOPHARMACOLOGICAL RELEVANCE

Aqueous root extract of Lecaniodiscus cupanioides is widely used in the management of sexual dysfunction in Nigeria. The effect of aqueous root extract of L. cupanioides root on the concentrations of penile cyclic Guanosine Monophosphate (cGMP) and plasma nitric oxide in paroxetine-induced sexually impaired male rats was evaluated.

METHODS

Thirty (30) albino rats were assigned into six groups (A, B, C, D, E and F) of five rats each such that animals in Group A (control) received distilled water while those in Groups B, C, D, E and F which were induced into sexual dysfunction (p.o 10mg/kg of paroxetine hydrochloride suspension in Tween-80) and in addition received distilled water, 7.14 mg/kg body weight of a reference herbal drug (PowmaxM), 25, 50 and 100mg/kg body weight of the extract respectively, orally, once daily for five days.

RESULTS

Administration of paroxetine significantly reduced the levels of penile cyclic Guanosine Monophosphate (cGMP) and plasma nitric oxide. These decreases were dose dependently reversed by the aqueous extract of L. cupanioides root. The reversal by the 25 and 50mg/kg body weight of the extract compared favorably with the PowmaxM, whereas the 100mg/kg body weight of the extract compared favorably with the non-sexually impaired distilled water treated control animals.

CONCLUSION

The results of this study show that aqueous extract of L. cupanioides root restored the levels of cGMP and nitric oxide in sexually impaired rats. This study further lends credence to the use of aqueous root extract of L. cupanioides in the management of sexual dysfunction in Nigeria.

Effects of ethanolic dried leaf extract of Lecaniodiscus cupanioides on antioxidant enzymes and biochemical parameters in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Lecaniodiscus cupanioides is widely used in West African folk medicine for the treatment of inflammatory conditions, fevers and bacterial infections.

AIM OF THE STUDY

To evaluate the potential toxic effects of the ethanolic dried leaf extract of Lecaniodiscus cupanioides (LC) on antioxidant enzymes in selected organs and biochemical parameters.

MATERIALS AND METHODS

Crude ethanolic extract of Lecaniodiscus cupanioides dried leaves was prepared. A 90-day sub-chronic toxicity study was conducted using albino rats. Reconstituted Lecaniodiscus cupanioides was administered at a dosage of 400, 800 and 1600 mg/kg (high dose) with a control group receiving 10 ml/kg orally. Histopathological studies of major organs and blood chemistry analysis were performed on blood obtained via cardiac puncture after euthanization. Selected organs (liver, kidney and brain) were harvested for antioxidant and histopathological assessments.

RESULTS

The extract produced significant (p<0.05) increases in the weights of liver, kidney and brain at 800 mg/kg and 1600 mg/kg compared to the control. Biochemical analysis showed significant increase in Alanine transferase (ALT) at 800 mg/kg and 1600 mg/kg. Assay for antioxidant enzymes showed a reversible decrease in the activity of Catalase (CAT), Superoxide dismutase (SOD) and Glutathione (GSH) with an increase in Malondialdehyde (MDA) at 800 mg/kg and 1600 mg/kg Lecaniodiscus cupanioides. Histopathological study showed reversible congestion in the brain, liver, and kidney at 800 mg/kg and 1600 mg/kg.

CONCLUSION

Findings in this study reveal that the ethanolic dried leaf extract of Lecaniodiscus cupanioides has the potential for inhibiting in vivo antioxidant enzymes activity and causing hepatotoxicity after prolonged exposure.

Phytochemical Analysis and Antimalarial Activity Aqueous Extract of Lecaniodiscus cupanioides Root

Root aqueous extract of Lecaniodiscus cupanioides was evaluated for antimalarial activity and analyzed for its phytochemical constituents. Twenty-four (24) albino mice were infected by intraperitoneal injection of standard inoculum of chloroquine sensitive Plasmodium berghei (NK 65). The animals were randomly divided into 6 groups of 3 mice each. Group 1 served as the control while groups II-IV were orally administered 50, 150, and 250 mg/kg body weights of extract. Groups 5 and 6 received 1.75 and 5 mg/kg of artesunate and chloroquine, respectively. The results of the phytochemical analysis showed the presence of alkaloids (2.37%), saponin (0.336), tannin (0.012 per cent), phenol (0.008 per cent), and anthraquinone (0.002 per cent). There was 100 per cent parasite inhibition in the chloroquine group and 70 per cent in the 50 mg/kg body weight on day 12, respectively. The mean survival time (MST), for the control group was 14 days, artesunate 16 days, and chloroquine 30 days, while the groups that received 50 and 250 mg/kg body weight recorded similar MST of 17 days and the 150 mg/kg body weight group recorded 19 days. The results obtained indicated that the aqueous extract of Lecaniodiscus cupanioides may provide an alternative antimalarial.

Effects of agomelatine on oxidative stress in the brain of mice after chemically induced seizures

Agomelatine is a novel antidepressant drug with melatonin receptor agonist and 5-HT(2C) receptor antagonist properties. We analyzed whether agomelatine has antioxidant properties. Antioxidant activity of agomelatine (25, 50, or 75 mg/kg, i.p.) or melatonin (50 mg/kg) was investigated by measuring lipid peroxidation levels, nitrite content, and catalase activities in the prefrontal cortex, striatum, and hippocampus of Swiss mice pentylenetetrazole (PTZ) (85 mg/kg, i.p.), pilocarpine (400 mg/kg, i.p.), picrotoxin (PTX) (7 mg/kg, i.p.), or strychnine (75 mg/kg, i.p.) induced seizure models. In the pilocarpine-induced seizure model, all dosages of agomelatine or melatonin showed a significant decrease in TBARS levels and nitrite content in all brain areas when compared to controls. In the strychnine-induced seizure model, all dosages of agomelatine and melatonin decreased TBARS levels in all brain areas, and agomelatine at low doses (25 or 50 mg/kg) and melatonin decreased nitrite contents, but only agomelatine at 25 or 50 mg/kg showed a significant increase in catalase activity in three brain areas when compared to controls. Neither melatonin nor agomelatine at any dose have shown no antioxidant effects on parameters of oxidative stress produced by PTX- or PTZ-induced seizure models when compared to controls. Our results suggest that agomelatine has antioxidant activity as shown in strychnine- or pilocarpine-induced seizure models.

Anticonvulsant effects of agomelatine in mice

Agomelatine is a potent MT1 and MT2 melatonin receptor agonist and a 5-HT2C serotonin receptor antagonist. We analyzed whether agomelatine has anticonvulsant properties. The anticonvulsant activity of agomelatine (25, 50 or 75 mg/kg, i.p.) was evaluated in mouse models of pentylenetetrazole (PTZ-85 mg/kg, i.p.), pilocarpine (400mg/kg, i.p.), picrotoxin (7 mg/kg, i.p.), strychnine (75 mg/kg, i.p.) or electroshock-induced convulsions. In the PTZ-induced seizure model, agomelatine (at 25 or 50mg/kg) showed a significant increase in latency to convulsion, and agomelatine (at 50 or 75 mg/kg) also increased significantly time until death. In the pilocarpine-induced seizure model, only agomelatine in high doses (75 mg/kg) showed a significant increase in latency to convulsions and in time until death. In the strychnine-, electroshock- and picrotoxin-induced seizure models, agomelatine caused no significant alterations in latency to convulsions and in time until death when compared to controls. Our results suggest that agomelatine has anticonvulsant activity shown in PTZ- or pilocarpine-induced seizure models.

Anticonvulsant action of Calotropis procera latex proteins

Calotropis procera (Ait.) R.Br. is a laticiferous plant belonging to the Apocynaceae family. C. procera latex proteins were evaluated with respect to anticonvulsant and sedative activity in mouse models of pentylenetetrazol (PTZ)-, pilocarpine-, and strychnine-induced convulsions or turning behavior and pentobarbital-induced sleep. In the strychnine- and pilocarpine-induced seizure models, C. procera latex proteins caused no significant alterations in latencies to convulsions and death, as compared with controls. In the PTZ-induced seizure model, administration of C. procera latex proteins in high doses (50 or 100mg/kg) and diazepam caused significant increases in latencies to convulsions and death. C. procera latex proteins (50 or 100mg/kg) and 2mg/kg diazepam caused a decrease in sleep latency and an increase in sleep time compared with the control group and groups treated with 5 or 10mg/kg. Our results suggest that C. procera latex proteins have a central nervous system-depressant activity as reflected in their potentiation of pentobarbital-induced sleeping time and their anticonvulsant action in the PTZ-induced seizure model.

Anticonvulsant activity of solasodine isolated from Solanum sisymbriifolium fruits in rodents

CONTEXT

Solanum sisymbriifolium Lam. (Solanaceae), commonly known as sticky nightshade, is traditionally used for central nervous system (CNS) disorders. Although solasodine has been isolated from this plant, little is known about its anticonvulsant and CNS depressant actions.

OBJECTIVE

We investigated anticonvulsant and CNS depressant effects of solasodine isolated from S. sisymbriifolium using several experimental models.

MATERIALS AND METHODS

Swiss albino mice (n=6) were employed for pentylenetetrazole (PTZ) and picrotoxin (PCT)-induced convulsions and thiopental-induced sleep time. Different groups of Wistar albino rats (n=6) were subjected to maximal electroshock (MES) test. Solasodine, a steroidal glycoalkaloid, was isolated from dried fruits of S. sisymbriifolium and identified by GC-MS.

RESULTS

The results showed that intraperitoneal (i.p.) injection of solasodine (25 mg/kg) significantly delayed (p < 0.01) latency of hind limb tonic extensor (HLTE) phase in the PCT-induced convulsions. In the MES model, solasodine significantly reduced (p < 0.001) duration of HLTE at 25, 50, and 100 mg/kg, i.p. in a dose-dependent manner. Interestingly, solasodine did not produce any significant reduction in PTZ-induced convulsions. Prior treatment of solasodine (25, 50, and 100 mg/kg, i.p.) significantly potentiated thiopental-provoked sleep in a dose-dependent manner (p < 0.001).

DISCUSSION AND CONCLUSION

Our study, for the first time, shows potent anticonvulsant and CNS depressant activities of solasodine. It is likely that solasodine, in part, is responsible for the anticonvulsant and sedative properties of S. sisymbriifolium. The future study should focus on the exact mechanism of action of solasodine.

Central action of Araucaria angustifolia seed lectin in mice

Possible central nervous system effects of the gymnosperm lectin from Araucaria angustifolia seeds were studied in seizure and open field tests. Male Swiss mice were administered saline (control), lectin (0.1, 1, and 10 mg/kg), flumazenil (1 mg/kg), or diazepam (1 mg/kg) intraperitoneally. Lectin at the highest dose increased time to death in the pentylenetetrazole- and strychnine-induced seizure models as compared with control, but not in the pilocarpine model. In the open field test, lectin reduced locomotor activity at all doses tested, as did diazepam, when compared with control. These locomotor effects were reversed by flumazenil pretreatment. In conclusion, A. angustifolia lectin had a protective effect in the pentylenetetrazole- and strychnine-induced seizure models, suggestive of activity in the GABAergic and glycinergic systems, respectively, and also caused a reduction in animal movements, which was reversed by flumazenil, pointing to a depressant action mediated by a GABAergic mechanism.

Anticonvulsant activity of hydroalcoholic extracts from Erythrina velutina and Erythrina mulungu

The anticonvulsant effects of hydroalcoholic extracts (HAEs) from the stem bark of Erythrina velutina and Erythrina mulungu on pentylenetetrazole (PTZ) and strychnine-induced seizure tests and the potentiation of pentobarbital-induced sleeping time in mice with the extracts were examined in this study. These medicinal plants belong to the Fabaceae family and are popularly used in Brazil for their effects on the central nervous system. The extracts of Erythrina velutina (intraperitoneally or orally) and Erythrina mulungu (intraperitoneally) were administered in mice at single doses (200 or 400mg/kg). While Erythrina velutina and Erythrina mulungu did not exhibit any protector effect in PTZ-induced seizures, at any dose, an increase in the latency of convulsion and in the death time was observed with both doses and routes of Erythrina velutina and at higher dose of Erythrina mulungu, in strychnine-induced seizure. No alteration was observed with Erythrina velutina and Erythrina mulungu on sleeping latency at both doses as compared to control (362.8+/-59.5). However, the sleeping time was increased in both plants as compared to control (943.8+/-129.6). In conclusion, we showed that the hydroalcoholic extracts of Erythrina velutina and Erythrina mulungu have anticonvulsant effects only in the strychnine-induced seizure model, suggesting their possible action in glycine system and a potentiation of pentobarbital sleeping time, suggesting depressant action in the central nervous system.