Towards a modern approach to traditional use: in vitro and in vivo evaluation of Alchemilla vulgaris L. gel wound healing potential

Abstract

Ethnopharmacological relevanceAlchemilla vulgaris is an important remedy in European folk medicine, known for its astringent and anti-inflammatory properties; it is traditionally used to heal gynecological and gastrointestinal diseases. Despite its folkloric use in wound healing, there is a lack of scientific data to support this therapeutic application. Aim of the studyTo analyze the wound healing potential of different solvent A. vulgaris extracts per se and after incorporation into hydrogels as topical vehicles, using two complementary methods - in vitro wound healing assay with L929 fibroblasts and in vivo assessment of skin barrier repair potential. Besides scientific justification of the traditional usage, we aimed to ephasize the importance of a proper vehicle for herbal extracts. The wound healing activity has been connected to the chemical profile of the investigated extracts, their antioxidative properties, but also to pH of the investigated gels and their mechanical characteristics. Materials and methodsAntioxidant activity of investigated extracts was estimated using both 2,2-diphenyl-1-picrylhydrazyl and β-carotene/linoleic acid models. Chemical profile was achieved applying spectrophotometric and HPLC methods. In vitro scratch assay with L929 fibroblasts, and in vivo study of skin barrier repair potential of hydrogels with A. vulgaris extracts on human skin employing biophysical measurements, were performed in order to confirm the wound healing potential of A. vulgaris. Texture analysis of the gels was performed alongside the pH measurements. ResultsAll tested extracts and gels accelerated the wound healing process while the effect of ethanolic extract on migration of fibroblasts was the most pronounced. The highest extent of wound closure was also observed for the ethanolic extract. The most favorable effect on in vitro wound healing was observed for gel with propyleneglycolic extract. Results of in vivo study were in line with in vitro findings. Healing potential may be attributed to phenolic compounds found in A. vulgaris extracts, low pH of the gels, and the satisfying antioxidant activity of the extracts. Parameters obtained by textural analysis indicated satisfying mechanical properties of the gels, relevant to topical application. ConclusionOur study offers pharmacological evidence on the folkloric use of A. vulgaris in wound treatment, particularly after incorporation into hydrogel, and underlines an importance of a proper vehicle for incorporation of herbal extracts intended for topical treatment.