Efficacy of Chromolaena odorata leaf extracts for the healing of rat excision wounds

Abstract

Injury to the soft tissues is followed by wound healing, which consists of four stages: haemostasis, inflammation, proliferation and remodelling. Chromolaena odorata is a weed that is traditionally used for the treatment of various ailments in humans and animals. The present study was aimed at exploring the wound healing potential of aqueous and ethanolic extracts of C. odorata in a rat excision wound model. This investigation involved phytochemical screening and in vitro analyses of various parameters such as antioxidant activity, lipid peroxide inhibitory activity and the effects of extracts on contraction and epithelialisation of the rat excision wounds. The phytochemical screening of both ethanolic and aqueous extracts showed that they were rich in secondary metabolites such as alkaloids, flavonoids, tannins, saponins, terpenoids, anthraquinones, cardiac glycosides and carbohydrates. The aqueous extract showed high antioxidant and lipid peroxide inhibitory activity, while the ethanolic extract showed high total phenol content and hydrogen peroxide inhibitory activity at concentrations of 50, 100 and 250 μg/ml. Our results also indicate that the most effective concentration of the C. odorata extract for excision wound healing was 5.0% (w/w). C. odorata-treated groups exhibited a faster reduction in wound area compared to control and Betadine-treated groups. In addition, the topical application of C. odorata extract increased collagen synthesis and its stabilisation at the wound site, as evidenced by the increase in hydroxyproline and hexosamine levels and expression of collagen. The present investigation demonstrates that aqueous and ethanolic extracts of C. odorata of varying concentrations promote an accelerated wound healing process and might represent a novel healing agent. Our findings are of potential clinical relevance and might be highly beneficial for drug discovery and development in the area of both human and veterinary medicine.