Exploring the relaxation effects of Coptis chinensis and berberine on the lower esophageal sphincter: potential strategies for LES motility disorders

Background: Esophageal achalasia, a primary disorder impacting the lower esophageal sphincter (LES), presents symptoms such as dysphagia, regurgitation, chest pain, and weight loss. Traditional treatments, including calcium channel blockers and nitrates, offer limited relief, prompting exploration into alternative therapies. This study examines the efficacy of Traditional Chinese Medicine (TCM), focusing on Coptis chinensis (C. chinensis) and its principal component, berberine, for modulating LES relaxation, offering a new perspective on treatment possibilities.

Methods: This research evaluated the impact of C. chinensis extract and berberine on the relaxation of LES contraction pre-induced by carbachol, observing the effects across different concentrations. We employed a series of inhibitors, including tetrodotoxin, ω-conotoxin GVIA, rolipram, vardenafil, KT5823, KT5720, NG-nitro-L-arginine, tetraethylammonium (TEA), apamine, iberiotoxin, and glibenclamide, to investigate the underlying mechanisms of berberine-induced LES relaxation.

Results: Both C. chinensis extract and berberine induced significant, concentration-dependent relaxation of the LES. The relaxation effect of berberine was significantly reduced by TEA, indicating the involvement of potassium channels in this process.

Conclusions: This study demonstrates that C. chinensis and berberine significantly promote LES relaxation, primarily through potassium channel activation. These findings provide a foundation for further investigation of these compounds' potential therapeutic applications in esophageal motility disorders, such as achalasia.