Effect of Rubia tinctorum L. Extractson Carrageenan-Induced Paw Edema in Rats

Background: Inflammation is a dynamic process that is elicited in response to various harmful stimulantsthat may threaten the well-being of the host. Herbs have been traditionally used as anti-inflammatory agents since very early times. Rubia tinctorum L. is one of these herbs that havebeen used for treating inflammatory diseases in Iranian traditional medicine. Objective: This study aims at considering anti-inflammatory effects of R. tinctorum and comparing its extracts in this property. Methods: The root of Rubia tinctorum (Rubiaceae) was collected from Yazd province, in the center of Iran. The root extracts of plant were studied for their anti-inflammatory activity by using carrageenan-induced hind paw edema in Wistarmale rats. Indomethacin and normal saline were used as positive and negative controls, respectively. Different concentrations of aqueous, ethanolic, and 50% aq. ethanolic extracts (600, 800, 1000 mg/kg) were given orally before carrageenan injection. The paw thickness was measured at 1, 3 and 5 hours after injection. Results: Both, aqueous and 50% eq. ethanolic extracts reduced paw edema at 600 and 800 mg/kg concentrations. Moreover, ethanolic extract showed significant effect only in1sthour after carrageenan injection. Conclusion: The results indicated that the aqueous extract were exhibited higher anti-inflammatory effect compared with other extracts. Accordingly, the potent anti-inflammatory effect of the root extracts is attributed to the polar compounds which are extracted in the water.