Evaluation of Wound Healing Activity of 80% Hydromethanolic Crude Extract and Solvent Fractions of the Leaves of Urtica simensis in Mice

BACKGROUND: Leaves of Urtica simensis (U. simensis) have been used traditionally for wound healing in different communities in Ethiopia. In spite of this, there were no scientific data documented regarding the wound healing activity of this plant. There is a need to investigate herbal remedies for the treatment of wounds in order to overcome the limitations of conventional drugs. AIM OF THE STUDY: Aim of the study was to evaluate the wound healing activity of extract and solvent fractions of the leaves of U. simensis in mice. METHODS: Leaves of U. simensis were washed, dried under shade and ground into coarse powder and then extracted by 80% methanol with three consecutive macerations. Part of the extract was fractionated with n-hexane, chloroform and water. In excision and burn wounds, healing progress was measured by wound contraction, epithelialization period and histopathology investigation whereas incision wound healing was assessed by skin breaking strength. RESULTS: In excision wound model, the 5% and 10% crude extract ointments showed significant (p < 0.001) wound contractions during day 8 to day 16 evaluations. Similarly, in burn wound model, both 5% and 10% crude extract ointments produced significant (p < 0.001) wound contractions starting from day 12 and 10, respectively. In both models, the periods of epithelialization were also significantly reduced and favorable histopathologic changes were produced by the crude extract ointments. The solvent fractions of the crude extract as well produced significant wound contractions as evaluated in excision wound model. The fractions also significantly reduced the period of epithelialization in this model. The aqueous fraction found to be more active than either chloroform or n-hexane fraction in wound healing. CONCLUSION: Results of this study indicated that methanol extract and aqueous fractions of the leaves of U. simensis possess dose-dependent wound healing activity, thus supporting traditional claims.