Multi‐omics analysis revealed the therapeutic mechanisms of Gegen (Puerariae Lobatae Radix) water extract against ischemia‐induced bladder overactivity through the inhibition of epoxide hydrolase 2

The potential effects of Puerariae Lobatae Radix (Gegen in Chinese) water extract (GWE) on overactive bladder (OAB) were previously demonstrated through ex vivo examination of detrusor contraction. However, the mechanisms were not fully understood. The current aim was to investigate the therapeutic mechanisms of GWE against OAB in spontaneously hypertensive rats (SHR) with bladder ischemia. The therapeutic effect of GWE against OAB was evaluated by urodynamics. Hematoxylin & eosin (H&E) staining, Masson staining, and Doppler ultrasonic blood stream detector were utilized to observe bladder structures and local blood flow, respectively. To elucidate the mechanisms, an integrated omics approach was employed. The key proteins and metabolites were validated using Western Blotting and ELISA. A 3-week treatment of GWE demonstrated a significant improvement in urodynamic parameters. The results from Doppler detector, H&E staining, and Masson staining indicated that GWE improved vasodilation of bladder microvessels. Transcriptomic analysis revealed changes in genes such as Ptgfr and Ntsr1, which were involved in regulating intracellular Ca2+ concentration. Proteomic analysis suggested that the downregulation of epoxide hydrolase 2 (EPHX2), maintaining the balance of epoxyeicosatrienoic acids (EETs), was responsible for GWE-induced vasodilation. Metabolomic analysis further supported alterations in arachidonic acid (AA) metabolism. It is concluded that GWE treated OAB in SHR rats by improving bladder blood flow through the inhibition of EPHX2 and upregulation of EETs. This inhibition resulted in the improvement of bladder structure and the suppression of AA metabolism-mediated PTGES/PTGFR/PLCβ1/phospho-MLC signaling pathway.