Analgesic, CNS depressant and antibacterial activities of ethanol extract of Spilanthes paniculata leaves

Spilanthes paniculata Wall. is an important medicinal plant which is used to treat toothache, throat and gum infections. The present study was aimed to investigate the analgesic, CNS depressant and antibacterial activities of the ethanol extract of Spilanthes paniculata leaves (SPE). Analgesic activity was determined by formalin and acetic acid induced writhing methods. The CNS depressant activity was determined by open field and hole cross test. Antimicrobial activity was evaluated by disk diffusion method. In acetic acid induced writhing method, the SPE showed significant writhing inhibition 66.92% (p<0.01) at a dose of 500 mg/kg body weight as compared to control. In formalin test, the SPE (500mg/kg) showed a significant licking inhibition 46.77% (p<0.01) In CNS depressant activity, test animals showed significant decrease (p<0.001) in number of movement with the treatment of SPE (500mg/kg) while diazepam (1mg/kg) was used as a standard drug. SPE at the dose of 800µg/disc showed moderate antibacterial activity against most of the gram positive and gram-negative bacteria. Thus, our study suggests that ethanol extract of Spilanthes paniculata may be a source of natural product having its analgesic and CNS depressant activities along with moderate antibacterial activity.