RÉSUMÉ
The investigation of novel phytochemicals for the prevention and treatment of infections caused by multidrug-resistant pathogens is gaining attention. The current study evaluated the in-vitro antimicrobial activity of kaempferol against methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. Its in-vivo efficacy in inhibiting these pathogens was determined using an excision wound model in nicotinamide-streptozocin- -induced diabetic rats. Kaempferol displayed an inhibitory effect against the tested bacteria both in vitro and in vivo. It also healed excision wounds at a 1% (w/w) concentration. An increase in antioxidant enzymes in wounded tissue was observed on kaempferol treatment. A reduction in the MRSA and P. aeruginosa counts in wounded tissue together with a reduced epithelization period was observed when compared to the infected control. A thicker epithelium, new capillaries, and a decrease in inflammatory cells were detected by hematoxylin and eosin staining. Furthermore, an increase in collagen fibers and their deposition was observed by Masson's trichrome staining. Kaempferol at 40 µM did not display any toxicity for human keratinocytes grown in media containing high glucose and it did not affect the expression of the pro-healing cytokines genes vascular endothelial growth factor (VEGF) and transforming growth factor-b-1 (TGFß1). Kaempferol displayed antibacterial and antioxidant actions but did not increase the expression of proliferative genes.