Analgesic Effect and Immunomodulation Response on Pro-Inflammatory Cytokines Production by Scrophularia megalantha Extract

Purpose: The remains unknown, To determine the analgesic and anti-inflammatory activities of Scrophularia megalantha in male rats in order to understand the scientific basis for its trado-medicinal uses, especially in inflammation. Methods: The extract of Scrophularia megalantha was obtained with ethanol. In order to determine qualitatively the chemical components of the extract, thin layer chromatography (TLC) was used. The analgesic activity of the extract at various doses (25, 50, 100 and 200 mg/kg, i.p) was assessed using formalin test while pro-inflammatory cytokines were measured by enzyme-linked immunosorbent assay (ELISA), respectively. Diclofenac (5 mg/kg) was used as positive control. Results: Phenolic compounds, flavonoids and phenyl propanoid were present in the extract. At doses of 100 and 200 mg/kg, the extract showed significant analgesic effects (p 0.05, p 0.01) in the first phases of formalin test, compared with the control. At 25, 100 and 200 mg/kg doses, the extract reduced significantly (p 0.05, p 0.001, p 0.001) pain score in the chronic phases of the formalin test. In addition, at 50 - 200 μg/mL of the extractm both TNF-α and IL-6 proinflammatory cytokines were inhibited significantly (p 0.001) on LPS-stimulated macrophages. Conclusion: The extract of S. megalantha exerts analgesic and anti-inflammatory activities by inhibition of pro-inflammatory cytokines production. This lends support for the use of the plant as an analgesic in traditional medicine.