Evaluation of 5% Robusta Coffee Extract Gel in Enhancing Angiogenesis, Collagen Deposition, and Wound Texture During Skin Graft Healing in Long Evans Rats

Abstract

Skin grafting remains a fundamental reconstructive technique for covering tissue defects, particularly in extensive wounds. Postoperative management typically involves the application of topical agents or modern wound dressings; however, these interventions often present limitations, such as high costs and limited availability—especially in resource-constrained settings. As a result, there is growing interest in exploring natural-based therapeutic alternatives. Among these, Coffea canephora (Robusta coffee) has emerged as a promising candidate due to its rich phytochemical profile, including chlorogenic acid (CGA), flavonoids, and saponins—compounds known for their antioxidant, antiinflammatory, and pro-angiogenic properties.This study aimed to evaluate the efficacy of a 5% Robusta coffee extract gel (RCEG) in promoting wound healing in a split-thickness skin graft model using Rattus norvegicus (Long Evans strain). Thirty male rats were randomly assigned to three experimental groups: a negative control group receiving gel base only, a positive control group treated with 1% kojic acid gel, and a treatment group administered 5% RCEG. A standardized 2 × 2 cm split-thickness skin graft was harvested from the dorsal region and transplanted onto the donor site. Histopathological samples were collected on postoperative days 7, 14, and 21 to assess angiogenesis and collagen density.Histological analysis revealed that the treatment group exhibited a statistically significant increase in neovascularization, along with enhanced collagen deposition and density, compared to both control groups at all time points (p < 0.05). Furthermore, macroscopic assessment of wound texture—based on visual evaluation of wound color and surface morphology using ImageJ—showed notable improvement in the RCEG group, indicating better wound integration and maturation.In conclusion, topical application of 5% Robusta coffee extract gel significantly accelerates the wound healing process in skin grafts by enhancing angiogenesis, increasing collagen synthesis, and improving wound surface characteristics. These findings suggest that RCEG is a promising, cost-effective natural adjunct for postoperative wound care