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

Objective: The aim of the present study was to investigate the therapeutic effect of ginsenoside Rb1(GS-Rb1) on urethral mechanical trauma in a rat model of stress urinary incontinence (SUI) and the underlying mechanisms. Design: 24 female rats were divided into four groups: (1) control; (2) SUI; (3) SUI+ L-Rb1; (4) SUI+ H-Rb1 group. SUI models were induced via vaginal dilation (VD). Control rats received sham surgery. Methods: The treatment rats received oral doses of ginsenoside Rb1 (4.5 mg/kg and 18 mg/kg, for the L and H groups, respectively) once per day for one week. Rats in the SUI group received the same volume of saline. On day 7, the leak point pressure (LPP) and maximum bladder capacity were evaluated and the rats were sacrificed. Urethral and vaginal wall tissue was examined using histology, immunohistochemistry, western blotting, and qPCR. Results: : GS-Rb1 treatment was found to reduce urethral mechanical trauma, allowing periurethral tissue recovery. GS-Rb1 also reduced the numbers of fragmented and disorganized elastic and muscle fibers through activation of Nrf2/AREand TGF-β1/Smad3, leading to increased collagen synthesis and ameliorating damage to the urethral fibromuscular system. Conclusion: GS-Rb1 effectively reduced mechanical trauma to the urethral fibromuscular system in an SUI rat model. This was mediated by activation of Nrf2 antioxidant activity and TGF-β1/Smad3 signaling.