Evaluation of analgesic activity of sodium valproate and ethanolic extract of Vitex negundo in experimental analgesic models in wistar rats

ABSTRACT

Background: NSAIDs and opioids are commonly prescribed medications to relieve pain of multiple aetiologies with no effect on the level of consciousness of the patient. They interfere with the mode of transmission of the pain message. A widely prescribed antiepileptic drug, sodium valproate has been used in various non-epileptic conditions like migraine prophylaxis and in the treatment of bipolar disorder because of the multiple mechanisms by which it acts. Vitex negundo has been investigated for antipyretic, analgesic, anti-inflammatory, anticonvulsant, hepatoprotective and bronchial relaxant. Very few studies have been done to evaluate its analgesic activity and no study was done on analgesic activity with the combination of modern drug. The more important point to be noted is that Vitex negundo is a natural product and therefore unlikely to cause adverse effects when compared to the traditional drugs used to treat pain. The aim of the present study was to evaluate of analgesic activity of sodium valproate and docosahexaenoic in experimental analgesic models in wistar rats.Methods: For analgesic activity, a total of 36 adult Wistar albino rats were taken and divided into six groups of six rats each. Group I was control (distil water 1ml/kg), Group II received intraperitoneal injection of diclofenac sodium (10mg/kg), Group III, IV were injected intraperitoneal sodium valproate 200, 400mg/kg with distil water respectively and Group V, VI were given sodium valproate 200, 400mg/kg (intraperitoneal) plus EEVN 400mg/kg (orally) respectively. Analgesic activity was assessed using hot plate, tail flick and acetic acid writhing models.Results: Present study revealed that sodium valproate at higher doses (400mg/kg) used either alone along with EEVN (400mg/kg) showed statistically significant analgesic activity in comparison to control in various experimental models for assessing pain.Conclusions: Combination of sodium valproate along with EEVN has shown promising analgesic activity.