Evaluation of wound healing activities of pomegranate (Punica granatum - Lythraceae) peel and pulp

Background: Wound healing is an active and complex process. Wounds cause serious problems in many cases, while there is no fast and reliable cure method. Numerous medicines, mostly as ointments, have been used to treat wounds. However, they can have some defects, limitations, and side effects. Therefore, exploration for new natural compounds for curing wounds is important. Traditional Iranian Medicine (TIM) is becoming popular, which can return patients to health with minimal side effects. Pomegranate is well reported for its medicinal properties. In TIM, Punica granatum fruits have been used to treat inflammatory disorders and wounds. Methods: In this study, 60 Wistar rats (male, 180 +/- 10 g) were used. The rats were randomly divided into five groups (each containing 12), including Eucerin as control; phenytoin as standard drug; the top layer of pomegranate peel (peel), pomegranate pulp (pulp), and peel + pulp as investigation groups. The back skin of deeply-unconscious animals was wounded (2 cm long). For 14 days from wound establishment, the wounds were treated topically with the medicines above. Wound length and improvement percentage were investigated by analyzing images of wounds. Three rats of each group were killed on days 3,7,10 and 14, and then the wounded skin were cut at a certain area for pathological studies. Epithelization; neovascularization; fibroblast, PMN and macrophage count were investigated. Results: All groups had significant (P<0.01) wound healing in comparison with the control group on all days, but phenytoin and pulp were the most effective. Phenytoin and peel significantly improved some histopathological parameters (P<0.05). Conclusion: Various parts of the pomegranate skin have different effects on wound healing. The extract of the top layer of the peel significantly improved the wound healing process, whereas that of the pulp showed no promising effects. Accordingly, the top layer of the peel is suggested for further studies on wound healing.