Evaluation of wound healing and anti-inflammatory activity of the leaves of Calpurnia aurea (Ait.) Benth (fabaceae) in mice

Ethnopharmacological relevance: The leaves of Calpurnia aurea (Ait.) Benth are used for wound healing activities through topical application in different communities in Ethiopia. The leaves had many confirmed in vitro activities that can promote wound healing effects. In spite of many claims and in vitro studies with supportive results in wound healing, no scientific study has been conducted on the wound healing and anti-inflammatory activity of leaves of Calpurnia aurea (Ait.) Benth on animals. Aim of the study: was to evaluate the wound healing and anti-inflammatory activity of leaves of Calpurnia aurea (Ait.) Benth scientifically in mice. Methods and materials: Air dried leaves of Calpurnia aurea (Ait.) Benth were grounded and macerated three times successively by 80% methanol. Then part of the dried extract was fractionated with chloroform, ethyl acetate and aqueous. Phytochemical screening tests were performed according standard test procedures. The crude extract and solvent fractions were formulated to ointments. The acute dermal toxicity of the crude extract was determined in rats. Wound healing activity of the crude extract was evaluated using excision and incision wound models and the wound healing activities of solvent fractions were evaluated by using excision wound model. The anti-inflammatory activity of the 80% methanol extract of leaves of Calpurnia aurea (Ait.) Benth was evaluated using carrageenan induced hind paw edema model in mice. Results: The 2000 mg/kg test dose of the 10% w/w crude extract ointment was safe in rats. The 5% w/w and 10% w/w crude extract ointments revealed significant (p < 0.001) wound contraction from day 4-day 8 post wounding. The 10% w/w crude extract ointment revealed a significant (p < 0.01) shortening of epithelialization period in excision wound model. Both 5% w/w and 10% w/w crude extract ointments showed significant (p < 0.001) increment of tensile strength compared to the negative control. The 10% w/w aqueous fraction ointment revealed high (p < 0.001) percentage of wound contraction and reduced (p < 0.001) period of epithelialization. The 100 mg/kg, 200 mg/kg and 400 mg/kg oral administration of the crude extract had significant inhibition of the paw edema in mice of carrageenan induced inflammation. Conclusion: The results of this study demonstrated that 80% methanol extract of the leaves of Calpurnia aurea (Ait.) Benth exhibited wound healing and anti-inflammatory effects. The aqueous and ethyl acetate fractions possessed wound healing activities.