Anti-Inflammatory and Histological Analysis of Skin Wound Healing through Topical Application of Mexican Propolis

Skin wound healing is a complex biochemical process of tissue repair and remodeling in response to injury. Currently, the drugs used to improve the healing process are inaccessible to the population, are costly, and have side effects, making the search for new treatment alternatives necessary. Propolis is a natural product produced by bees that is widely recognized and used in folk medicine for its multiple biomedical activities. However, therapeutic information regarding Mexican propolis is limited. This study aimed to evaluate the wound-healing effect of the Chihuahua ethanolic extract of propolis (ChEEP). Macroscopic and histological analyses were performed using a mouse wound-healing model. The topic acute toxicity assay showed that propolis at 10% w/v had no toxic effects. ChEEP has antibacterial activity against the Gram-positive bacteria Staphylococcus aureus and Staphylococcus epidermidis. Moreover, it exhibited good anti-inflammatory activity evaluated through mouse ear edema induced by 12-O-tetradeca-noylphorbol-13-acetate (TPA). A full-thickness incision lesion was created in mice and treated topically with 10% ChEEP. At Day 14 post-treatment, it was observed that propolis increased wound contraction and reduced healing time and wound length; furthermore, propolis increased the tensile strength of the wound, as determined with the tensiometric method, and promoted the formation of type I collagen at the site of injury, as evaluated with Herovici stain. These findings suggest that the topical administration of ChEEP can improve skin wound healing, probably due to the synergistic effect of its components, mainly polyphenols, in different steps of the wound-healing process. It should be noted this is the first time that the wound-healing activity of a Mexican propolis has been evaluated.