Humic Acid Enhances Wound Healing in the Rat Palate

Abstract

Introduction: Humic acid was previously shown to enhance cutaneous wound healing and show antibacterial properties; however, it has not been used for wound healing in the oral cavity. Thus, the goal of this study was the evaluation of the effect of the humic acid on the healing of excisional wounds in an experimental rat study.

Materials and methods: A circular wound on mid-palatal surfaces was made on a total of 77 Wistar rats by using a 3-mm biopsy punch under anesthesia. The animals were divided into 4 groups as baseline, saline control (0.09%), chlorhexidine gluconate (0.05%), and humic acid (80 mg/kg) and were treated with these materials for 7 days.

Results: The rats were observed for 3 weeks in order to track the wound closure rates. Both humic acid treatment and chlorhexidine gluconate treatment resulted in statistically significant enhanced rate of wound closure compared to the saline control on both the 1st and 2nd weeks of treatment. Humic acid treatment for the wounds in the palate resulted in enhanced recovery compared to not only saline control but also chlorhexidine gluconate treatment.

Conclusion: In this study, humic acid was shown to enhance healing of oral wounds for the first time in the literature. These findings indicate that humic acid can be used as an alternative to current treatment methods for oral wounds.

Figure 1

The representative light microscopic photographs of the wound areas on weeks 1, 2, and 3.

Figure 2

The representative histological image of the wound areas. (A) Representative histological image of the humic acid treated wounds at 1st week. The red star shows the wide necrotic and severely inflamed area, while the black star points to the mucosal epithelium. (B) Representative histological image of the humic acid treated wounds at 3rd week. The red star shows the mildly inflammatory area and granulation tissue, while the black stars show the constricted mucosal epithelial layer. (C) A representative section of humic acid treated tissues at the end of the study. Black star shows complete mucosal epithelial repair and healing.