The Effect of Ethanolic Extract of Scrophularia striata on Pain in Male Rats

Background: Scrophularia striata plant containing anti-inflammatory compounds and have nitric oxide production inhibiting properties. So can be an analgesic and act particularly on inflammatory kind of pain. Objective: The effect of ethanolic extract from aerial parts of Scrophularia striata was investigated on pain with formalin test in the male rats. Methods: In this study 40 Wistar male rats (250 to 300 g) were used and 8 animals were divided into five groups: 1.Control: (solvent), 2- Diclofenac (5 mg/kg), 3 - 6. Groups: Use extract with doses 25, 50, 100 and 200 mg intraperitoneally. At test time, the extract solved with 10 µl DMSO and diluted by adding PBS and injected into the peritoneum (0.5 ml volume). After 30 minute, 50 µl formalin 2.5% injected to the right foot floor subcutaneously and the animalchr('39')s pain behavior were recorded every 15 seconds for about 60 minutes. The final data of both acute and chronic pain phases were analyzed separately by using one-way ANOVA. Results: In the acute phase, administration of 100 and 200 mg/kg doses of Scrophularia striata decreased symptoms of pain than the control group (p <0.05, p <0.01). In the chronic phase, the extract caused a significant reduction in pain scores compared to controls, especially in doses of 100 and 200 mg/kg (p <0.01). Conclusion: Our results showed that peripheral injection of ethanolic extracts of Scrophularia striata can significantly produces analgesic effects and provides most pain alleviation on the chorionic phase of the formalin test.