Eleutherococcus senticosus Fruit Extract Stimulates the Membrane Potential of the Trachea and Small Intestine in Rabbits

Background: Eleutherococcus senticosus (Rupr. et Maxim.) Maxim., widely used in Russian and Chinese traditional medicine for its anti-inflammatory activity, contains bioactive compounds capable of stabilizing epithelial function and reducing inflammation. Despite prior research on its effects in the colon, the impact and mechanism of action of E. senticosus fruit extract on epithelial tissues of the upper digestive and respiratory tract remains unexplored. Objectives: This study aimed to evaluate the influence of E. senticosus fruit extract on the transepithelial electrical potential and resistance in the tracheal and small intestinal epithelium of rabbits. In addition, the chemical composition of the extract was also profiled by the means of UHPLC-DAD-MS. Methods: Tissue segments from the trachea and small intestine of New Zealand white male rabbits were examined using the Ussing chamber technique. Three concentrations of E. senticosus fruit extract (0.001, 0.1, 10 mg/100 mL) were applied, and changes in transepithelial electrical potential (dPD) and resistance (R) were recorded. Chemical analysis of the extract was conducted using UHPLC-DAD-MS. Results: For the first time, we have discovered that the E. senticosus extract increased membrane resistance in tracheal tissue, suggesting enhanced barrier integrity. In contrast, a slight decrease in resistance was observed in small intestinal tissue. UHPLC-DAD-MS confirmed the presence of chlorogenic acid, dicaffeoylquinic acids, quercetin derivatives, and myo-inositol, compounds known for their antioxidant, anti-inflammatory, and membrane-stabilizing effects. Conclusions: The differential response of respiratory and intestinal epithelium to the E. senticosus extract highlights its tissue-specific action and supports its traditional use in the prevention and treatment of diseases characterized by epithelial barrier dysfunction, such as asthma, COPD, and Crohn’s disease.