EVALUATION OF WOUND HEALING ACTIVITY OF 80 % METANOL CRUDE EXTRACT AND SOLVENT FRACTIONSOFTHE LEAVES OF VERNONIA AURICULIFERA HEIRN (ASTERACEAE) IN MICE

Abstract

Background: Medicinal plants play an important role in treating various diseases. Vernonia auriculifera Heirn is one of the medicinal plants used traditionally for the management of wounds. However, there were no scientific reports documented so far on the wound healing activities to substantiate the claim. Thus, the present study provides a scientific evaluation for the wound healing potential of the crude extract and solvent fractions of the leaves of the plant in mice. Methods: Air-dried leaves of Vernonia auliculifera were extracted by maceration using 80 % methanol and part of the crude extract fractionated with chloroform, ethyl acetate and aqueous solvents. Mice and rats were employed for wound healing study and dermal toxicity test respectively. Mice were randomly grouped into four groups in excision and burn wound models whereas five groups in incision wound (each 6 mice) assigned for crude extract. For fractions, eight groups in excision and nine groups in incision model were assigned. Nitrofurazone was used as positive control in Excision model of crude and fractions while silver sulphadiazine for burn model but simple ointment served as negative control in each model. Wound healing effects were evaluated by percent of wound contraction, period of epithelialization, tensile strength and histological analysis as parameters in excision, incision and burn wound models. Finally, the data were expressed as mean ± SEM and the results were analyzed using one-way ANOVA followed by Post Hoc Tukey-test. Results: In excision wound model, the 10 % (W/W) crude extract ointment has showed significant wound contraction (P < 0.001) from day 4 to day 18 as compared to the negative control. Similarly, 5 % w/w ointment has shown a significant wound contraction at 4 th, 6th, 8th and 10th (P < 0.05) and on day 12th (P < 0.01). Both the 5 % W/W (P < 0.001) and 10 % W/W (P < 0.05) crude extract ointments have showed statistically significant difference in epithelialization period as compared to the negative control. Groups treated with the ethyl acetate and aqueous fractions ointments in incision wound model, showed statistically significant (P < 0.001) increase in tensile strength. In incision model, the 10 % W/W and 5 % W/W ointments of the crude extract showed significant (P < 0.001) increase in breaking strength compared to simple ointment and the untreated control groups. In burn wound model, significant reduction in epithelialization period was observed in 5 % W/W (P < 0.05) and 10% W/W (P < 0.001) and the ix percentage of wound contraction was significantly increased in most of post wounding days by 10 % W/W (P < 0.001) and 5 % W/W (P < 0.05) crude extract ointments and compared to the negative control. Conclusion: The crude, aqueous and ethyl acetate fraction of Vernonia auriculifera leaves possess wound healing activities. This finding justifies the use of the leaves of this plant for wound as claimed in the traditional medicine literatures.