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

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. This study aims at considering anti-inflammatory effects of R. tinctorum and comparing its extracts in this property. 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. 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. 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.