Screening for wound healing effects in terrestrial fungi

Despite improvements in conventional wound management adequate care of chronic wounds is still a challenge, especially in the light of demographic issues. As treatments are expensive and in part ineffective, new concepts and strategies improving chronic wound care are desirable. Alternative investigation focuses on atmospheric pressure plasmas, different honey types, and natural product research. To screen for stimulatory effects on wound relevant human cells an in vitro wound model (scratch assay) using HaCaT human keratinocytes (Boukamp et al., DKFZ Heidelberg) was established. Briefly, HaCaT monolayers were scratched using a 4-rowed cell scraper. Scratch areas were calculated after 24 and 48 hours. To minimize unspecific stimulation of cell migration/proliferation, cells were cultivated in low glucose medium containing only 1% FCS. Calendula officinalis crude extract, allantoin, ascorbic acid and dexamethasone served as controls. Watery and ethanolic resp. methanolic crude extracts from fruiting bodies of Ganoderma lucidum, Ganoderma pfeifferi, Lentinula edodes, Calvatia gigantea and Piptoporus betulinus were tested in different concentrations. A statistically significant reduced time to „wound closure“ (p≤0.05; Tukey HSD) was found for watery and ethanolic L. edodes and methanolic C. gigantea extracts, allantoin and ascorbic acid. A reduced wound closure speed was found for the ethanolic extracts of both Ganoderma species and dexamethasone. In future, this assay shall be used to further screen crude extracts of terrestrial and marine origin for wound related effects. L. edodes extract will be fractionated bioassay guided to reveal the active compounds.