The effects of Feijoa sellowiana fruit extract on wound healing in rats: a stereological and molecular study

The aim of this study was to evaluate the anti-inflammatory and wound-healing potential of Feijoa sellowiana fruit extract using stereological and molecular methods in experimental rat models.

Male Wistar rats were divided into four equal groups: non-treated, vehicle, Feijoa sellowiana fruit extract ointment (5% weight/weight) and the reference drug (madecassol). All animals were treated topically once per day. At the end of the study, wound samples were harvested for histological, stereological, immunohistochemical and molecular assessments to determine the in vivo healing potential and anti-inflammatory activity. A high-performance liquid chromatography (HPLC) analysis was performed for the characterisation of the phenolic acids in the extract.

The study included 64 rats in total. Our results showed that the wound closure, volume of new epidermis and dermis, density of fibroblasts and blood vessels, and the deposition of collagen were significantly higher in both extract and madecassol groups compared to the non-treated and vehicle groups, with superior healing in the extract group. The transcript for the transforming growth factor (TGF)-β gene was significantly upregulated in both extract and madecassol groups compared to non-treated and vehicle groups and was highest for the extract group. The density of inflammatory cells and expression levels of the cyclooxygenase (COX)-2 protein and tumour necrosis factor (TNF)-α gene in the extract and madecassol groups, especially in the extract group, were significantly reduced compared to non-treated and vehicle groups.

Our results confirm that the Feijoa sellowiana fruit extract is a valuable source of antioxidant and anti-inflammatory activities and can allow for damaged tissue in wounds to recover markedly.