Behavioral and antiepileptic effects of acute administration of the extract of the plant Cestrum nocturnum Lin (lady of the night).

Cestrum nocturnum is a garden shrub from the family Solanaceae and is used as a remedy for different health disorders. The aim of the present work was to investigate the potential neuropharmacological action profile of decoctions obtained from dry leaves of the plant. Decoctions were tested in different neuropharmacological models-Irwin test, exploratory behavior, tests for analgesia, isoniazid- and picrotoxin-induced convulsions, and maximal electroshock seizures-in mice, as well as in amphetamine-induced stereotypies and penicillin epileptic foci in rats. Decoctions of 1 and 5% (D1 and D5) induced restlessness, and the 30% decoction (D30) induced passivity. D5 and D30 reduced significantly exploratory behavior and amphetamine-induced stereotypies within a 3-hour observation period. The latter effect was apparent during the second 60 minutes. Decoctions reduced the amount of writhes induced by acetic acid in a dose-dependent manner, but were not effective in the hot plate model. The decoctions were not effective against pharmacologically induced convulsions. However, repeated administration of five doses of D5, at 1-hour intervals, reduced the amplitude of penicillin-induced epileptic spikes in both primary and secondary foci, in curarized rats. Taken together, the results suggest that C. nocturnum possesses active substances with analgesic activity provided through a peripheral action mechanism, in parallel with some psychoactive activity that does not fit well the neuropharmacological action profile of known reference neurotropic drugs.

Behavioral and antiepileptic effect of acute administration of the extract of the aquatic plant Echinodorus berteroi (Sprengel) Fassett (upright burhead).

Echinodorus berteroi is an aquatic plant found in Central America and the Caribbean to which antiepileptic action has been attributed by folk medicine. The aim of the present study was to investigate the potential behavioral and antiepileptic effect of decoctions (1, 5, and 30%, intraperitoneally) of the dried roots. One and five percent decoctions produced hypoactivity in mice. Hyperactivity induced by amphetamine (3mg/kg, subcutaneously) was significantly reduced by the 30% decoction, in rats. The extracts did not modify the latency to the first clonic convulsion or the survival time of isoniazid (210 mg/kg, ip)-treated mice. The 30% decoction significantly increased the latency to the first picrotoxin-induced clonic convulsion (7 mg/kg, intraperitoneally), as well as survival time. Repeated administration of the 5% decoction (30-minute intervals) significantly reduced the amplitude (muV) of the epileptic spikes induced by topical application of penicillin to sensorimotor cortex, in curare-treated rats. In summary, the root decoctions of E. berteroi paradoxically exhibited neuroleptic and antiepileptic actions. Nevertheless, these results partly justify the use of the plant for the treatment of epilepsy by practitioners of folk medicine.

Acute effect of an extract of Ambrosia paniculata (Willd.) O. E. Schultz (mugwort) in several models of experimental epilepsy.

The acute effect of Ambrosia paniculata was studied in several animal models of epilepsy. Intraperitoneal injections (0.01 mL/g body wt) of a decoction of the dry leaves significantly enhanced the latency to the first convulsion and survival time in mice injected with picrotoxin (7 mg/kg) or isoniazid (210 mg/kg). Epileptic spikes were induced by topical application of penicillin through a glass electrode filled with a penicillin-agar-saline mixture and recorded in sensorimotor and occipital cortices, in rats immobilized with d-tubocurarine. The plant decoction reduced significantly the spike amplitude in both sites. The mentioned effects were elicited at doses that also reduced general motor activity (Irwin test) and exploratory behavior. The decoctions were not effective against electroshock-induced convulsions in mice. The convulsions induced by isoniazid, picrotoxin, and penicillin differed from those induced by electroshock implicating selective disruption of GABAergic neurotransmission. The results suggest that A. paniculata, like several conventional antiepileptic drugs, might act by enhancing GABAergic neurotransmission, a hypothesis that requires further demonstration. These results explain and justify the traditional use of the plant in epilepsy.