Tea component, epigallocatechin gallate, potentiates anticataleptic and locomotor-sensitizing effects of caffeine in mice.

Tea is the most popular beverage worldwide. Caffeine, the psychoactive principle of tea, pharmacologically interacts with several drugs and bioactive molecules. Epigallocatechin gallate (EGCG) is a major component of tea and its known interactions with caffeine make it worthwhile to further study them by investigating the influence of EGCG on the anticataleptic and locomotor-sensitizing effects of caffeine. In the present investigation, we observed that (a) administration of caffeine or EGCG alone inhibited haloperidol-induced catalepsy, a widely used animal model to study parkinsonism, and (b) a combination of caffeine and EGCG produced greater inhibition of haloperidol-induced catalepsy. Furthermore, after repeated administration of caffeine and EGCG, either alone or in combination, we observed that (c) caffeine and EGCG contrasted the sensitization of catalepsy observed after repeated haloperidol administration by significantly reducing the duration of catalepsy. Furthermore, as haloperidol-induced catalepsy was also associated with increased lipid peroxidation, we observed that (d) EGCG administration reduced striatal lipid peroxide levels in a dose-dependent manner and that (e) the combination of caffeine with EGCG was most effective in reducing haloperidol-increased striatal lipid peroxide. Finally, we observed that (f) chronic caffeine and EGCG significantly elicited locomotor sensitization and that (g) their combination resulted in significantly greater effects. In conclusion, EGCG potentiated the effects of caffeine on haloperidol-induced catalepsy and of caffeine-elicited locomotor sensitization. Overall, these observations indicate critical interactions between caffeine and EGCG in an animal model of parkinsonism and locomotor activity and suggest that tea consumption might reduce antipsychotic-induced side effects.

Ethanolic extract of Rubia peregrina L. (Rubiaceae) inhibits haloperidol-induced catalepsy and reserpine-induced orofacial dyskinesia.

In the traditional Sardinian system of medicine, Rubia peregrina L. (Rubiaceae) is reported as an aphrodisiac herb. Since the aphrodisiacs may also have antioxidant and dopaminergic activities, the aim of this study was to study the effect of ethanolic extract of aerial parts of R. peregrina for the scavenging of free DPPH radicals and the inhibition of haloperidol-induced catalepsy in mice and reserpine-induced orofacial dyskinesia in rats. The extract exhibited significant antioxidant activity in a free radical DPPH assay with IC(50) = 55.6 µg mL(-1), which was very close to IC(50) of ascorbic acid. The extract of R. peregrina (100 and 200 mg kg(-1) intraperitoneally, i.p.) significantly inhibited haloperidol (1 mg kg(-1) i.p.) - induced catalepsy in mice (p < 0.01). In rats, the extract (200 mg kg(-1) i.p.) significantly (p < 0.01) inhibited the orofacial dyskinesia induced by intraperitoneal administration of reserpine (1 mg kg(-1) on days 1, 3 and 5). This study demonstrates that R. peregrina has antioxidant activity and improves the dopaminergic function. Results therefore justify the development of further experiments to investigate the psychopharmacological profile of R. peregrina.

Anti-inflammatory activity of Pistacia lentiscus essential oil: involvement of IL-6 and TNF-alpha.

The topical anti-inflammatory activity of essential oil of Pistacia lentiscus L. was studied using carrageenan induced rat paw edema and cotton pellet induced granuloma. The effect on serum tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) in rats inserted with cotton pellet was also investigated. On topical application, the oil exhibited a significant decrease in paw edema. The oil also inhibited cotton pellet-induced granuloma, and reduced serum TNF-alpha and IL-6. It can be concluded that the essential oil of Pistacia lentiscus reduces leukocyte migration to the damaged tissue and exhibits anti-inflammatory activity.

Anxiolytic and antiemetic activity of Zingiber officinale.

The benzene fraction (BF) of a petroleum ether extract of dried rhizomes of ginger, which contained anticonvulsant principle(s), was screened for anxiolytic and antiemetic activity. Motor coordination was not affected by BF per se, but diazepam-induced motor incoordination was potentiated. Animals treated with BF showed decreased occupancy in the closed arm of the elevated plus maze suggesting the presence of anxiolytic principles in the BF. BF also blocked lithium sulphate-induced conditioned place aversion indicating antiemetic activity. These findings suggest that the fraction (BF) possesses anticonvulsant, anxiolytic and antiemetic activity.

Anxiolytic and anticonvulsive activity of Sesbania grandiflora leaves in experimental animals.

Various parts of Sesbania grandiflora have been used in the Indian system of medicine, in particular, the leaves of S. grandiflora are used in Ayurveda for the treatment of epileptic fits. In the present study we have evaluated the anticonvulsive activity of S. grandiflora leaves using a variety of animal models of convulsions. Bioassay guided separation was also carried out to identify the fraction possessing anticonvulsant activity. The benzene:ethyl acetate fraction (BE) of the acetone soluble part of a petroleum ether extract significantly delayed the onset of convulsions in pentylenetetrazol (PTZ) and strychnine (STR)- induced seizures in mice and reduced the duration of tonic hindleg extension in the maximum electroconvulsive shock (MES) induced seizures in mice. The BE contained a triterpene as a major component. In addition, the BE also inhibited electrically induced kindled seizures in mice and lithium-pilocarpine-induced status epilepticus in rats. It prolonged the duration of sleep induced by pentobarbital and antagonized the effect of D-amphetamine. Mice treated with BE preferred to remain in the open arm of the elevated plus maze indicating anxiolytic activity. The BE raised the brain contents of gamma-aminobutyric acid and serotonin. Thus the triterpene containing fraction of S. grandiflora exhibits a wide spectrum of anticonvulsant profile and anxiolytic activity.

Nootropic activity of Albizzia lebbeck in mice.

The effect of saponin containing n-butanolic fraction (BF) extracted from dried leaves of Albizzia lebbeck on learning and memory was studied in albino mice using passive shock avoidance paradigm and the elevated plus maze. Significant improvement was observed in the retention ability of the normal and amnesic mice as compared to their respective controls. We have also studied the effects of BF on the behavior influenced by serotonin (5-HT), noradrenaline and dopamine. The brain levels of serotonin, gamma-aminobutyric acid (GABA) and dopamine were also estimated to correlate the behavior with neurotransmitter levels. The brain concentrations of GABA and dopamine were decreased, whereas the 5-HT level was increased. The data indicate the involvement of monoamine neurotransmitters in the nootropic action of BF of A. lebbeck.

Anticonvulsive activity of Butea monosperma flowers in laboratory animals.

The bioassay-guided fractionation of dried flowers of Butea monosperma (BM) was carried out to isolate the active principle responsible for its anticonvulsant activity. The petroleum ether extract was fractionated by column chromatography using solvents of varying polarity such as n-hexane, n-hexane:ethyl acetate, ethyl acetate, and methanol. The anticonvulsive principle of B. monosperma was found to be a triterpene (TBM) present in the n-hexane:ethyl acetate (1:1) fraction of the petroleum ether extract. TBM exhibited anticonvulsant activity against seizures induced by maximum electroshock (MES) and its PD(50) was found to be 34.2+/-18.1 mg/kg. TBM also inhibited seizures induced by pentylenetetrazol (PTZ), electrical kindling, and the combination of lithium sulfate and pilocarpine nitrate (Li-Pilo). However, TBM was not effective against seizures induced by strychnine and picrotoxin. TBM exhibited depressant effect on the central nervous system. After repeated use for 7 days, the PD(50) (MES) of TBM increased to 51.5+/-12.1 mg/kg. Similarly, after repeated use of TBM, the duration of sleep induced by pentobarbital was not reduced significantly. Further studies are required to investigate its usefulness in the treatment of epilepsy.