Kangfuxin solution alleviates esophageal stenosis after endoscopic submucosal dissection: A natural ingredient strategy.

Abstract

Background: Esophageal stricture ranks among the most significant complications following endoscopic submucosal dissection (ESD). Excessive fibrotic repair is a typical pathological feature leading to stenosis after ESD.

Aim: To examine the effectiveness and underlying mechanism of Kangfuxin solution (KFX) in mitigating excessive fibrotic repair of the esophagus post-ESD.

Methods: Pigs received KFX at 0.74 mL/kg/d for 21 days after esophageal full circumferential ESD. Endoscopic examinations occurred on days 7 and 21 post-ESD. In vitro, recombinant transforming growth factor (TGF)-β1 (5 ng/mL) induced a fibrotic microenvironment in primary esophageal fibroblasts (pEsF). After 24 hours of KFX treatment (at 1.5%, 1%, and 0.5%), expression of α-smooth muscle actin-2 (ACTA2), fibronectin (FN), and type collagen I was assessed. Profibrotic signaling was analyzed, including TGF-β1, Smad2/3, and phosphor-smad2/3 (p-Smad2/3).

Results: Compared to the Control group, the groups treated with KFX and prednisolone exhibited reduced esophageal stenosis, lower weight loss rates, and improved food tolerance 21 d after ESD. After treatment, Masson staining revealed thinner and less dense collagen fibers in the submucosal layer. Additionally, the expression of fibrotic effector molecules was notably inhibited. Mechanistically, KFX downregulated the transduction levels of fibrotic functional molecules such as TGF-β1, Smad2/3, and p-Smad2/3. In vitro, pEsF exposed to TGF-β1-induced fibrotic microenvironment displayed increased fibrotic activity, which was reversed by KFX treatment, leading to reduced activation of ACTA2, FN, and collagen I. The 1.5% KFX treatment group showed decreased expression of p-Smad 2/3 in TGF-β1-activated pEsF.

Conclusion: KFX showed promise as a therapeutic option for post-full circumferential esophageal ESD strictures, potentially by suppressing fibroblast fibrotic activity through modulation of the TGF-β1/Smads signaling pathway.