(PTFS11-01-23) Phenolic Extract(s) From Wild Blueberries Upregulate EGFR and FGF7 Proteins for Epidermal Skin Regeneration During Wound Re-Epithelialization.

Objectives: Complete re-epithelialization (WRE) is important for wound healing. However, epidermal re-epithelization is a major challenge in chronic wounds such as diabetic and ischemic ulcer. Previously, our laboratory reported significant wound closure with phenolic (PE) fractions from Wild Blueberry (WB). However, the pathway(s) for this effect are unknown. Thus, this study examines the effect of PE from WB at different concentrations on WRE as a pathway for wound closure in a rat model.

Methods: Phenolic acids were extracted from WB through the Folin-Ciocalteu method. The extract was then incorporated into a gel and a cream base. Fifty-six Sprague-Dawley rats were placed into seven groups as follows: Group 1, Control (no treatment), Group 2, cream carrier
without the PE, Group 3, gel carrier, without PE, Group 4, gel with 500 ug/ml of the PE, Group 5, cream with 500 ug/ml of PE, Group 6, gel with 1000 ug/ml of PE, and Group 7, cream with 1000 ug/ml of PE. Dorsal wounds were created on all rats and treated for six days. Following treatment, wound areas were excised and fixed for molecular and histological analyses. The wounds were stained with H&E, imaged with a motic brightfield microscope, and scored for re-epithelization using Qu-path software. Re-epithelization proteins EGFR and FGF7 were assessed by western blotting.

Results: The histology results analysis showed complete wound re-epithelialization with the gel 500 ug/ml of the PE and significant increases in EGFR ( < 0.0001 p-values) and FGF7 ( < 0.01 p-values) protein expression.

Conclusions: This research may benefit patients with chronic wounds by developing treatments from wild blueberries that would promote adequate epidermal regeneration by upregulating the fibroblasts and keratinocytes markers (FGF7 and EGFR) for wound re-epithelialization.

Funding Sources: The Wild Blueberry Association of North America
The University of Maine Medicine Seed Grant Program
The Maine Innovation Research Technology Accelerator
USDA National Institute of Food and Agriculture
The Maine Technology Institute
National Science Foundations –Innovation Corps
The Graduate School of Biomedical Sciences and Engineering
The Bioscience Society of Maine