Sophora flavescens Extracts Have Therapeutic Effects on Overactive BladderSyndrome by Potentiation of Large-Conductance Calcium-ActivatedPotassium Channel

ABSTRACT

Sophora flavescens Ait. (Fabaceae) is a medicinal plant widely founded in Northeast Asia, and its dried root (Kushen) has been used as a traditional Chinese herbal medicine. The therapeutic effects of Kushen in micturition disorder was not investigated comprehensively yet. In the present study, we examined and compared the efficacy of three batches of Kushen extract using different ethanol content through an in vitro cell-based assay. Among them, we chose the batch with the highest efficacy and augmented the volume of extract for industrial purpose. The bulk extract was examined in its efficacy in the in vitro cell-based assay, and the therapeutic effects through an in vivo behavioral assay of OAB rats. The main components of the extracts were analyzed by liquid chromatography. Cytotoxicity of the extracts was investigated by MTT assay. The overall efficacy of the extract was as much as, or more than, kurarinone, a potent BKCa channel activator. Thus, the extract was a potent relaxant of urinary smooth muscle by upregulating the activity of BKCa channel. The Kushen extract could be explored as an alternative medicine against overactive bladder patients indicating severe dysfunction of BKCa channel