Dampened inflammatory response in oral ulcer after topical therapy of adipose mesenchymal stem cell secretome

Objectives: Research has demonstrated that modulating inflammation can significantly accelerate the healing of oral ulcers. Our study focused on the adipose mesenchymal stem cell secretome (AdMSCS), which is rich in immunoregulatory molecules capable of dampening the immune response and interfering with inflammatory pathways. We assessed both inflammatory pathway expression and macrophage phenotypes at the sites of oral ulcers. Methods: We induced oral ulcers in the inferior fornix mucosa of 20 healthy male Wistar rats (Rattus norvegicus). These subjects were treated topically with adipose MSC metabolite (AdMSCM) oral gel three times daily, for durations of 3 and 7 days. We performed immunohistochemical analyses to evaluate the expression of Toll-like receptor 4 (TLR4) and nuclear factor kappa B (NF-κB) p65 at the ulcer sites. Additionally, we assessed macrophage polarization by examining the ratio of M2/M1 macrophages, identified through CD68⁺Φ (M1) and CD163⁺Φ (M2) cells. Data were analyzed using one-way analysis of variance, followed by post-hoc Tukey's Honestly Significantly Difference test. Results: Application of AdMSCM oral gel significantly reduced the expression of TLR4 and NF-κB p65. This treatment also enhanced macrophage polarization towards the anti-inflammatory M2 phenotype at the ulcer sites (p < 0.05). Conclusion: The topical application of AdMSCM oral gel effectively modulates the inflammatory response, enhancing healing processes in the oral ulcer rat model. This suggests its potential utility as a therapeutic agent in managing oral ulcers.