Some pharmacological effects of an ethanolic extract of Palisota ambigua on the central nervous system in mice

The present study investigates some neuropharmacological effects of an ethanol extract of the leaves of Palisota ambigua (Commelineae), a medicinal plant in Central Africa. Intraperitoneal administration of the extract induced hyperthermia and reduced the writhing response induced by acetic acid. In addition, the extract augmented the duration of sleeping time induced by sodium pentobarbital and delayed the onset of clonic seizures induced by pentylenetetrazole. By contrast, the extract did not affect convulsions induced by maximal electroschock and picrotoxin.     

Laminaria ochroleuca: A preliminary study of its effect on the central nervous system

The effects were studied of a methanolic extract of the brown alga Laminaria ochroleuca on the central nervous system (CNS) of mice. Spontaneous motor activity, exploratory behaviour, motor coordination, d-amphetamine-induced hypermotility, body temperature, pentobarbital-induced hypnosis, pentylenetetrazole-induced convulsions and analgesic activity were assessed. At doses between 25 and 100mg/kg, the extract showed significant activity in all tests except that of pentylenetetrazole-induced convulsions. It is concluded that the methanolic extract of Laminaria ochroleuca is a CNS depressant with slight analgesic activity.     

Terpenoids Isolated from Psidium guajava Hexane Extract with Depressant Activity on Central Nervous System

A bioguided fractionation of the hexane extract obtained from Psidium guajava leaves led to the isolation of sesquiterpenes with depressant activities on the central nervous system. The results demonstrated that the already reported relaxant properties of Psidium guajava hexane extract are largely due to the presence of terpenes, especially caryophyllene-oxide and β-selinene, which were by far the largest single components and potentiated pentobarbital sleeping time and the latency of convulsions induced by leptazol in mice. Calcium concentration-response curves showed a rightward displacement when the active fraction was added to isolated guinea-pig ileum depolarized with K⁺ (60 mm ) and cumulative concentrations of CaCl₂, suggesting that caryophyllene-oxide, a known Ca²⁺ antagonist agent could be responsible for the blockade of extracellular Ca²⁺ observed with the active fraction.     

Isolation of jacaranone,a sedative constituent extracted from the flowers of the Mexican tree Ternstroemia pringlei

Ethnopharmacological relevance

Ternstroemia pringlei represents one of the most widely employed and commercially exploited medicinal plant in Mexico, used popularly as a tranquilizer and for the treatment of insomnia.

Aim of the study

To investigate the sedative constituents of the plant through a bio-guided fractionation of extracts derived from calyx and fruits.

Materials and methods

Crude extracts with different polarities (CHCl₃, AcOEt, MeOH, aqueous) were prepared and subjected to chromatographic fractionation, leading to the isolation of the sedative compound (1) from the MeOH crude extract. The identity of 1 was unequivocally established by means of 1D and 2D NMR spectroscopic analysis. The sleeping time induced by sodium pentobarbital and the elevated plus-maze models were performed on mice to determine the sedative and anxiolytic activities, respectively. Bioactivity was also investigated though in vitro GABA release experiments using mice brain slices.

Results

The sedative compound was established as jacaranone (1), and its effect was clearly demonstrated through a dose-dependent response analysis (ED₅₀ = 25 mg/kg mouse weight). When tested in the elevated plus-maze model, none of the extracts from Ternstroemia pringlei displayed anxiolytic activity. GABA release experiments showed that the MeOH and aqueous crude extracts released this neurotransmitter at a ratio of 217 and 179 pmol/g protein, respectively, evidencing the presence of other bioactive constituents in the extracts apart of 1, whose activity was absent in this model.

Conclusions

Although 1 has been isolated and identified in a number of plant species, this is the first time that its sedative effect has been demonstrated. No previous record exists of other sedative compounds having been isolated from Ternstroemia pringlei.     

Pharmacological investigations of sticky viscome extract (Cleome viscosa L.) in rats,mice and guinea-pigs

The aqueous extract of seeds of Cleome viscosa L. has been studied for its pharmacological activities. It was found to be nontoxic when dosed orally and intraperitoneally to rats and mice. The extract showed significant analgesic activity in mice and local anaesthetic activity in guinea-pigs. It potentiated the barbiturate sleeping time in rats and had a mild laxative effect, increasing the passage of soft faeces. It failed to protect against convulsions induced by picrotoxin in rats. The results are discussed in terms of the alleged uses of the plant in folklore medicine.     

Terminalia arjuna extract modulates the contraction of rat aorta induced by KCl and norepinephrine

The bark of Terminalia arjuna is in clinical use for the management of cardiovascular disorders in India. The objective of this study was to investigate the contractile response induced by the extract on rat aorta, a vascular smooth muscle. Terminalia arjuna relaxed the contraction, induced by both KCl (60 mM ) and norepinephrine (NE, 3 μM ). Inhibition was more prominent (80%) in the NE induced contraction than the KCl induced contraction (30%). Under similar conditions diltiazem, a calcium channel blocker (Dz, 1.0 μM ), inhibited 68% of the KCl induced and 30% of NE induced contraction. Thus it appears that the action of Terminalia arjuna extract differs from that of diltiazem in that it is more specific for alpha-adrenergic receptor agonists. It indirectly inhibited the contraction induced by norepinephrine by acting on K (Ca) channel by hyperpolarizing the smooth muscle membrane.     

Scavenging Effect of Aged Garlic Extract and its Constituents on Active Oxygen Species

The effect of aged garlic extract (AGE) and its major organosulphur constituents, S -allylcysteine (SAC), S -allylmercaptocysteine (SAMC) and alliin on active oxygen species were examined in an in vitro system. AGE and three compounds have demonstrated a scavenging effect on hydrogen peroxide, and also inhibited the chain oxidation induced by a hydrophilic radical initiator.     

Inhibitory effects of various ayurvedic and Panamanian medicinal plants on the infection of herpes simplex virus-1 in vitro and in vivo

Extracts of 40 Ayurvedic medicines and 39 Panamanian medicinal plants were screened for their inhibitory activity on the plaque formation of herpes simplex virus type 1 (HSV-1) in cultured cells. The extracts of 11 plant species showed potent inhibitory activity at a concentration of 100 μg/mL, while those of ten species showed moderate activities. Repeated oral administration of each extract of Rhus acuminata (galls), Saraca indica (bark), Strychnos potatrum (seeds) appreciably suppressed the development of typical skin lesions induced by infection of HSV-1 in BALB/c mice. The extract of S. potatrum prolonged both development of skin lesion and mean survival time. This indicates that S. potatrum is a possible candidate for therapeutic application for HSV-1 infection.     

Neuropharmacologial effects of Cystoseira usneoides extract

The effects were studied of an extract of the brown algae Cystoseira usneoides on the central nervous system (CNS) of mice. At doses between 6.25 and 25 mg/kg the extract had significant effects on spontaneous locomotor activity, exploratory behaviour, D-amphetamine-induced hypermotility, body temperature, pentobarbitalinduced hypnosis, motor coordination and pentylenetetrazole-induced convulsions. Dopamine, 3,4-dihydroxy-phenylacetic acid, 3-methoxytyramine and homovanilic acid levels were determined in rat striatum and they were slightly modified. The extract also displayed analgesic activity. We conclude that the extract of Cystoseira usneoides is a CNS depressant with slight analgesic effects.     

Toxicity of Senna obtusifolia fresh and fermented leaves (kawal), Senna alata leaves and some products from Senna alata on rats

The present study investigated the effects induced on albino rats by Senna obtusifolia fresh leaves and fermented (kawal) leaves, S. alata leaves, as well as the ethanol extract and pure compounds, namely, emodin, kaempferol, aloe-emodin, and rhein from the latter species. The present results indicate that the leaves of both S. obtusifolia and S. alata can cause marked toxic effects on rats, and that the processing of the leaves of the former species by fermentation to produce kawal did not alter the toxic activity of the ingredients in the leaves. Also the ethanol extract and compounds isolated from S. alata can cause subtle hepatorenal toxicity. Moreover, the present study suggests that anthraquinones have a mechanism of synergistic action when used collectively as present in the leaves. © 1998 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.     

Effect of Plant Polyphenols on Ischemia‐Reperfusion Injury of the Isolated rat Heart and Vessels

In the present study, we investigated the potential protective effect of selected natural substances in a rat model of heart and mesenteric ischemia‐reperfusion (I/R). Experiments were performed on isolated Langendorff‐perfused rat hearts, subjected to 30‐min global ischemia, followed by 30‐min reperfusion. Arbutin, curcumin, rosmarinic acid and extract of Mentha x villosa were applied in the concentration of 1 × 10^?5 mol/l 10 min before the onset of ischemia and during reperfusion, through the perfusion medium. Mesenteric ischemia was induced by clamping the superior mesenteric artery (SMA) for 60 min, subsequent reperfusion lasted 30 min. Production of reactive oxygen species (ROS) by SMA ex vivo was determined by luminol‐enhanced chemiluminiscence (CL). The effect of the substances was tested after their incubation with tissue. Curcumin and extract of Mentha x villosa were found to be the most effective in reducing reperfusion‐induced dysrhythmias ‐ ventricular tachycardia and fibrillation. This effect was accompanied by bradycardic effect. The mesenteric I/R induced an increase in CL in vascular tissue which was dampened by substances tested. All substances tested were found to have antioxidant properties, as demonstrated by a reduction in ROS production in mesenteric vessels. This effect was confirmed in curcumin and extract of Mentha x villosa which reduced reperfusion dyshythmias. Copyright © 2012 John Wiley & Sons, Ltd.     

Evaluation of the anti-stress and anticonvulsant activities of leaf extract of Alchornea cordifolia in mice

Aim of the study

The extract of the leaves of Alchornea cordifolia (AC) is extensively used in ethnomedicine for ulcers, rheumatic pains, febrile convulsions and for enhancing physical performance. In this study, the anti-stress and anticonvulsant activities of the aqueous leaf extract of Alchornea cordifolia were investigated in mice.

Materials and methods

The anti-stress activity was assessed based on the ability of the extract to alter the duration of immobility, in the forced swim endurance test, whilst a picrotoxin-treated animal, was employed as the model for convulsive seizures.

Results

The extract (100–400 mg/kg) given orally was found to significantly (p < 0.05) reduce the duration of immobility, which suggest an anti-stress/anti-fatigue property. However, AC when tested at doses between 100 and 400 mg/kg did not prevent convulsions induced by picrotoxin in mice. The acute toxicity study carried out in mice revealed that the extract was well tolerated by the animals, as no death was observed at oral doses of 500–4000 mg/kg.

Conclusions

The results of this preliminary study provide evidence, which may support the use of Alchornea cordifolia against stress or fatigue in ethnomedicine.     

Anticonvulsant effects of Searsia dentata (Anacardiaceae) leaf extract in rats

Searsia species are used in South Africa to treat epilepsy. Previous studies have demonstrated an in vitro N‐methyl‐D‐aspartic acid (NMDA) receptor antagonistic effect of the ethanolic leaf extract. The aim of this study was to evaluate the potential anticonvulsant properties of the ethanolic extract of S. dentata in various animal models of epilepsy. The extract was submitted to a screening in anticonvulsant assays including NMDA‐, kainic acid (KA)‐, pentylenetetrazol (PTZ)‐ and bicuculline (BIC)‐induced seizures in rats. The extract protected 47% of the PN 18 Wistar pups (postnatal day 18, date of birth PN 0) (p < 0.05, n > 10) against NMDA‐induced seizures and significantly delayed the onset of PTZ‐induced seizures (p < 0.05, n > 8) at a dose of 250 mg/kg. A dose optimum was detected at 500 mg/kg for protection against KA‐(63% protection, p < 0.05, n > 8) and BIC‐induced seizures (50% protection, p < 0.05, n > 8) in young adult and PN 18 rats, respectively. The ethanolic extract of S. dentata showed anticonvulsive properties in several models of epilepsy. These results are compatible with previous findings of NMDA receptor antagonism. Due to the complex composition of the extract, the effect might be caused by more than one compound. Copyright © 2009 John Wiley & Sons, Ltd.     

Antiinflammatory activity and effects on isolated smooth muscle of extracts from different Teucrium species

The present study analyses the antiinflammatory effects and the action on in vitro motility of methanol and dichloromethanol extracts and stems of four Teucrium species (T. flavum, T. cartaginenses, T. buxifolium and T. pumillum). The antiinflammatory activity was tested in the carrageenan-induced paw oedema in rats. T. flavum methanol (200 mg/kg, i.p.) and dichloromethanol (138 mg/kg, i.p.) extracts showed a significant anti-inflammatory effect through the 24 h experimental period and reduced the E_max induced by histamine and serotonin in vitro on guinea-pig ileum and rat uterus respectively. These extracts did not modify the contractile effects induced by acetylcholine on rat duodenum and noradrenaline on rat vas deferens. The methanol extracts of T. pumillum (50 mg/kg, i.p.) and T. buxifolium (26 mg/kg, i.p.) exhibited significant antiinflammatory effects only in the acute phase of the oedema (2 h) without affecting the chronic phase (24 h). In guinea-pig ileum, rat uterus and rat vas deferens, the methanol extract of T. pumillum reduced the maximal effect induced by histamine, serotonin and noradrenaline, respectively, whereas the methanol extract of T. buxifolium lacked any effect on the contractile activity induced by various agonists in vitro. When tested for antiinflammatory activity the methanol (200 mg/kg, i.p.) and dichloromethanol (200 mg/kg, i.p.) extracts of T. cartaginenses did not modify the oedematous response induced by carrageenan administration.     

Chemoprotective effects of Ulva lactuca (green seaweed) aqueous‐ethanolic extract against subchronic exposure to benzo(a)pyrene by CYP1A1 inhibition in mice

The protective effect of the supplementation with an aqueous‐ethanolic extract obtained from Ulva lactuca (Delile) green seaweed on benzo[a] pyrene‐induced damage in mice was evaluated. Animals were treated with oral doses of U. lactuca extract (100 and 400 mg/kg) for 9 weeks. They were exposed to 50 mg/kg of oral doses of benzo(a)pyrene starting from the second week and up to the fifth week. Groups treated with benzo(a)pyrene only (second to fifth weeks), sunflower oil (vehicle, 9 weeks), or U. lactuca extract (100 and 400 mg/kg, 9 weeks) were also included in the study. The treatment with 400 mg/kg of the extract ameliorated the oxidative damage, decreased IL‐1β and TNF‐α levels, and favorably regulated the antioxidant defenses compared with benzo(a)pyrene‐exposed group. The benzo(a)pyrene‐induced DNA damage was also reduced, as it was evidenced by the lower micronucleus formation in U. lactuca extract‐supplemented animals. The extract protected the hepatic tissue, and it reduced the liver activity/expression of CYP1A1. These results altogether suggested a chemoprotective effect of U. lactuca extract against benzo(a)pyrene‐induced‐toxicity in mice, probably associated with an inhibitory effect of carcinogen bioactivation.     

The hypoglycaemic activity of Swertia japonica extract in streptozotocin induced hyperglycaemic rats

The hypoglycaemic activity of an aqueous ethanolic extract of Swertia japonica and its ethyl acetate, n-butanol, water soluble fractions, together with ether soluble and insoluble fractions of ethyl acetate soluble fraction was observed in streptozotocin (STZ) induced hyperglycaemic rats. It was found that an aqueous ethanolic extract was more effective than a mixture of tolbutamide and buformine, and an ethanolic extract of another species of this plant, S. chirayita in lowering the blood glucose level under similar experimental conditions. Furthermore, an ethyl acetate soluble fraction of S. japonica and its ether insoluble fraction showed a potent hypoglycaemic activity.     

Behavioural effects of crude and semi-purified extracts of Syzygium cuminii linn. skeels

In this study, different extracts, fractions and subfractions from the seeds of Syzygium cuminii Linn. Skeels, have been evaluated for behavioural effects in mice, particularly in relation to their sedative and anticonvulsant actions. Oral treatment with the hydroalcoholic extract showed an anticonvulsant activity in pentylenetetrazol- and maximal electroshock-induced convulsions, besides a hypothermic effect. The infusion, the aqueous and ethyl acetate fractions of the hydroalcoholic extract, as well as the subfractions of the latter subfraction, promoted a decrease in spontaneous activity of mice after i.p. but not after p.o. treatment. The ethyl acetate fraction and its subfractions enhanced latency and duration of the first convulsion induced by pentylenetetrazol. One of the subfractions of the ethyl acetate fraction, a mixture of about five polyphenolic compounds, whose main constituent is gallic acid, also presented a depressant profile without an anticonvulsant activity. Our results suggest that S. cuminii has some active principles with central depressant properties, and some of them also present an anticonvulsant action, although the polyphenolic compounds do not seem be the main constitutents responsible for this effect. Copyright © 1998 John Wiley & Sons, Ltd.