Evaluation of wound healing and anti-inflammatory activity of the rhizomes of Rumex abyssinicus J. (Polygonaceae) in mice

BACKGROUND Rumex abyssinicus Jacq (Polygonaceae) is widely used in Ethiopia for treatment of wound and other diseases. Although reports are available in the literature on some of the claimed activities, nothing has so far been reported about the wound healing activity of R. abyssinicus. Thus, this work was initiated to investigate the wound healing and anti-inflammatory activities of 80% methanol extract of the rhizomes of R. abyssinicus in mice. METHODS Following extraction of the rhizomes of the plant with 80% methanol, the extract was formulated as ointment (5% & 10% w/w) with simple ointment base B.P. The ointment was then evaluated for wound healing activity using excision and incision wound models. Parameters, including wound contraction, epithelization time and hydroxyproline content were determined using the excision model, whereas tensile strength was measured from the incision model. In parallel, anti-inflammatory activity of the rhizome was evaluated with carrageenan induced hind paw edema model by dissolving the 80% methanol extract in 1% carboxyl methyl cellulose and administering orally in various doses (250, 500 and 750 mg/kg). RESULTS Wound treated with 5% and 10% (w/w) hydroalcoholic extract ointment exhibited significant wound healing activity in both models, as evidenced by increased wound contraction, shorter epithelization time, higher tissue breaking strength and increased hydroxyproline content. The hydroalcoholic extract also produced dose-related significant reduction (p < 0.05-0.001) of inflammation. CONCLUSIONS The results of this study demonstrated that the hydroalcoholic extract of the rhizomes of R. abyssinicus facilitated wound healing at least in part via its anti-inflammatory activity, supporting its traditional claim as a wound healing agent.