Evaluation of central nervous system stimulating and analgesic activities of Murraya koenigii leaves

Background/Introduction: Murraya koenigii Linn. (Family: Rutaceae), commonly known as curry patta, is a deciduous shrub found abundantly throughout India and in other tropical parts of the Asian subcontinent. It is traditionally used for several medicinal and folklore purposes as astringent, aromatic, demulcent, depurative, anthelmintic, febrifuge, stomachic, appetizing, carminative, anodyne, constipation, anti-inflammatory, antiseptic, tonic, etc. The leaves are rich in carbazole alkaloids, a class of compounds that are suggested to have stimulating effects on the central nervous system (CNS). Purpose/Aim: The study was performed to evaluate the CNS stimulating and analgesic activities of M. koenigii leaves. Methods: The leaves were extracted with ethanol and phytochemically screened. The CNS stimulating activity was tested by a rat forced swim test and barbiturate-induced sleeping time model, and the analgesic activity was evaluated by the hot-plate and tail-flick test models. Results: The yield of leaf extract was 9.75%. The CNS stimulating activities were exhibited by selected doses in both the models; in the rat forced swim test model, the duration of sleep at 600 mg/kg was significantly (p < 0.01) reduced, that is, 79.56 +/- 1.37 seconds as compared with the control. However, in the barbiturate-induced sleeping time model, the dose of 200 mg/kg was more effective, as onset and duration of sleep were 1650.16 +/- 6.74 seconds and 308.33 +/- 5.29 seconds, respectively, which are lower than that observed with standard caffeine (112.41 +/- 2.67 seconds and 1158.47 +/- 3.23 seconds, respectively). The average response time at the dose of 600 mg/kg in the hot-plate and tailflick models was found to be 11.2 +/- 0.04 seconds and 6.77 +/- 0.05 seconds (at 120 minutes and 180 minutes), respectively, which is more prominent than lower dose (300 mg/kg) and comparable with the standard group. Conclusion: It is evident that ethanol extract of M. koenigii leaves exhibits CNS stimulating and analgesic activities in in vivo models. Copyright (C) 2014, Taiwan Society of Emergency Medicine. Published by Elsevier Taiwan LLC. All rights reserved.