Antipsychotic activity of standardized Bacopa extract against ketamine-induced experimental psychosis in mice: Evidence for the involvement of dopaminergic, serotonergic, and cholinergic systems.

CONTEXT: Schizophrenia is a chronic disabling psychiatric disorder affecting 1% of the population worldwide. Due to the adverse effects of available antipsychotic medications, recent investigations have focused on the search for well-tolerated, safe molecules from natural resources to control the severity and progression of schizophrenia. OBJECTIVE: To screen the standardized extract of Bacopa monniera Linn. (Scrophulariaceae) (BM) for its antipsychotic potential in the ketamine-induced psychosis model with mice. MATERIALS AND METHODS: Graded dose of BM (40, 80, and 120 mg/kg, p.o.) were given to the mice 1 h prior to ketamine administration and tested for positive symptoms and cognitive deficits. A chronic ketamine treatment regimen was used to study the effect of BM on negative symptoms such as immobility enhancement. Each mouse was used once for the behavioral studies. RESULTS: BM reduced ketamine-induced hyperactivity with an EC50 value of 76.60 mg/kg. The 80 mg/kg dose was used for all other behavior analysis. Pretreatment with BM at 80 mg/kg showed two-fold increases in transfer latency time (TLT) in passive avoidance task. Chronic BM pretreatment (80 mg/kg p.o. daily × 10 d) ameliorated the ketamine-induced enhanced immobility effect by 21% in the forced swim test. BM treatment reversed ketamine-induced increase in monoamine oxidase activity in both cortex and striatum and normalized the acetylcholinesterase activity and the glutamate levels in the hippocampus. DISCUSSION AND CONCLUSION: Overall our findings suggest that BM possesses antipsychotic properties which might be due to its modulatory action on dopamine, serotonin, and glutamate neurotransmission.

A comparative study of magnesium sulfate vs dexmedetomidine as an adjunct to epidural bupivacaine.

BACKGROUND AND AIMS: This prospective, randomized, double-blind study was undertaken to establish the effect of addition of magnesium or dexmedetomidine, as an adjuvant, to epidural bupivacaine in lower limb surgeries. MATERIALS AND METHODS: One hundred and twenty ASA (American Society of Anesthesiologists) class I and II patients undergoing lower limb surgeries were enrolled to receive either magnesium sulfate (Group M) or dexmedetomidine (Group D) along with epidural bupivacaine for surgical anesthesia. All the study subjects received an epidural anesthesia with 14 ml of 0.5% bupivacaine along with either MgSO4 50 mg (Group M) or dexmedetomidine 0.5 µg/kg (Group D) or saline (Group C). The onset of motor and sensory block, duration of block, hemodynamic parameters, and any adverse events were monitored. RESULTS: Analgesia in the postoperative period was better in Group D, duration of sensory and motor blockade was significantly prolonged in Group D and incidence of sedation was more in Group D. CONCLUSION: Hence, addition of dexemedetomidine to epidural bupivacaine can be advantageous with respect to increased duration of motor and sensory blockade and arousable sedation.

Anxiolytic effects of Plumeria rubra var. acutifolia (Poiret) L. flower extracts in the elevated plus-maze model of anxiety in mice.

Interest in alternative medicine and plant-derived medications that affect the "mind" is growing rapidly since last two decades. The aim of the present study was to investigate the effects of ethanolic extract of flower of Plumeria rubra (PR) along with its fractions in the elevated plus-maze (EPM) model of anxiety. The P. rubra extract or its fractions was administered orally to male Swiss mice, at graded doses, 1h prior to behavioural assessment. The PR extract at the dose of 100mg/kg p.o., significantly increased the time spent in the open arms of the EPM. Further, the anxiolytic properties of hexane, chloroform and butanolic soluble and insoluble fractions at one-fifth of the original dose were also observed in the EPM task. Out of which butanol insoluble fraction showed significant anxiolytic activity comparable to standard anxiolytic drug, diazepam. Further, pretreatment with crude ethanolic extract and butane insoluble fraction showed no significant effects in the horizontal activity, total distance travelled and stereotypy count in the animal activity monitor and had no motor in-coordination side effects in the rotarod test in mice. These observations suggest that the flower extract of P. rubra and its insoluble butanolic fraction might possess significant anxiolytic potential to be pursued further for drug development process.

Evaluation of the antipsychotic potential of Panax quinquefolium in ketamine induced experimental psychosis model in mice.

The search for novel pharmacotherapy from medicinal plants for psychiatric illnesses has progressed significantly from the past few decades and their therapeutic potential has been assessed in a variety of animal models. The aim of our study was to screen one such plant, Panax quinquefolium (PQ), with significant neuroactive properties for its antipsychotic potential. A graded dose study with PQ at 12.5-200 mg/kg, p. o. showed differential effects against the ketamine induced hyperactivity in the Digiscan animal activity monitor. Nevertheless at 100 mg/kg, p.o., PQ blocked ketamine induced memory impairment in the passive avoidance paradigm. In the chronic studies, PQ reduced the ketamine induced enhanced immobility in the forced swim test and did not show extra-pyramidal side effects in bar test and wood block test of catalepsy. These behavioural effects were compared with standard drugs haloperidol and clozapine. Further PQ reduced DA and 5-HT content after chronic treatment, but not after acute administration. In addition, PQ extract reduced acetylcholinesterase activity and nitrate levels, however increased glutamate levels in hippocampus. Overall our findings suggest that PQ possess antipsychotic like properties, which may leads to future studies with its specific constituents which may particularly be beneficial in predominant negative and cognitive symptoms of schizophrenia.