Therapeutic effect of Ginsenoside Rb1 against mechanical trauma in rat model of postpartum stress urinary incontinence

Stress urinary incontinence (SUI) was mainly caused by childbirth which injured the urethra and surrounding tissues’ structural integrity. Promoting periurethral structure repair and preventing its further damage had the potential to treat SUI. Ginsenoside Rb1(GS-Rb1) was one of the important monomer extracts of traditional Chinese medicine ginseng and notoginseng, which had anti-inflammatory, anti-oxidation, and promotion of tissue repair effects. In this study, we demonstrated the effects and the mechanism of GS-Rb1 on SUI induced by mechanical trauma by establishing of SUI rat model by vaginal distension(VD) method. We found that GS-Rb1 alleviated the symptoms associated with SUI and significantly decreased the number of fragmented and disorganized elastic and muscle fibers in the urethra and anterior vaginal wall of SUI rats, and increased collagen content, reduced the disruption of the structural integrity in the periurethral myofiber. Furthermore, GS-Rb1 promoted the expressions of TGF-β1, Smad2, Smad3, Smad7, p-Smad3, p-Smad2, collagens I and III, also increased the protein levels of Nrf2, GPX1, and MnSOD. Thus, our study identified that GS-Rb1 effectively reduced mechanical trauma to the urethral fibromuscular system in an SUI rat model. This study identifies GS-Rb1 as a TGF-β1/Smad3 and NRF2/ARE signaling pathway agonist and provides a potentially practical pharmacological approach for treating postpartum mechanical trauma SUI.