Astragaloside IV Protects Detrusor from Partial Bladder Outlet Obstruction-Induced Oxidative Stress by Activating Mitophagy through AMPK-ULK1 Pathway

Aims. Bladder outlet obstruction (BOO) and the consequent low contractility of detrusor are the leading causes of voiding dysfunction. In this study, we aimed to evaluate the pharmacological activity of astragaloside IV (AS-IV), an antioxidant biomolecule that possess beneficial effect in many organs, on detrusor contractility and bladder wall remodeling process. Methods. Partial BOO (pBOO) was created by urethral occlusion in female rats, followed by oral gavage of different dose of AS-IV or vehicle. Cystometric evaluation and contractility test were performed. Bladder wall sections were used in morphology staining, and bladder tissue lysate was used for ELISA assay. Primary smooth muscle cells (SMCs) derived from detrusor were used for mechanism studies. Results. Seven weeks after pBOO, the bladder compensatory enlarged, and the contractility in response to electrical or chemical stimuli was reduced, while AS-IV treatment reversed this effect dose-dependently. AS-IV also showed beneficial effect on reversing the bladder wall remodeling process, as well as reducing ROS level. In mechanism study, AS-IV activated mitophagy and alleviated oxidative stress via an AMPK-dependent pathway. Conclusion. Out data suggested that AS-IV enhanced the contractility of detrusor and protected the bladder from obstruction induced damage, via enhancing the mitophagy and restoring mitochondria function trough an AMPK-dependent way.