Coumestrol/hydroxypropyl-β-cyclodextrin association incorporated in hydroxypropyl methylcellulose hydrogel exhibits wound healing effect: in vitro and in vivo study

Several beneficial effects on the skin have been reported for coumestrol (COU), such as protection against photoaging and improvement of skin elasticity and thickness in postmenopausal women. However no reports on the effect of COU on wound healing were found. Nevertheless, COU has low aqueous solubility, which is a crucial limitation for biological tests. The present study was designed as a two-step experiment to evaluate the wound healing effect of COU. First, we used fibroblasts and the experimental in vitro artificial wound model, scratch assay, to compare the effects of COU free, dissolved in dimethyl sulfoxide (DMSO) or Dulbecco's modified Eagle's medium (DMEM), or associated with hydroxypropyl-beta-cyclodextrin (HP beta CD). The 50 mu M (66.1%) and 10 mu M (56.3%) COU/HP beta CD association induced cell proliferation and migration in inflicted wounds. Subsequently, the in vivo wound healing experimental model (Wistar rats) revealed that COU/HP beta CD incorporated into hypromellose (HPMC) hydrogel had similar efficacy in wound healing in comparison to the positive control (Dersani (R)), with the advantage that 50% wound healing was achieved within a shorter period. In summary, the results successfully demonstrated, for the first time, the wound healing effect of COU/HP beta CD incorporated into HPMC hydrogel and describe the feasibility of the biological tests with the use of HP beta CD instead DMSO.