Page 18 - I. Chemical biology and drug discovery

[I. Chemical biology and drug discovery-10]

Sophora flavescens extracts elicit therapeutic effects on

overactive bladder syndrome by activating the large-

conductance calcium-activated potassium channel

Heeji Jo¹, Jisun Han¹, Narasaem Lee¹, Hyun Jun Lee², Sung Joo Jang³, Seunghwan Ryu³, Sang Hyun Moh³,

Jae Hoon Cheong², Chul-Seung Park¹

¹School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 61005, South Korea, ²Department

of Pharmacy, Sahmyook University, Seoul 01795, South Korea, ³Anti-Aging Research Institute, BIO-FD&C Co., Ltd,
Incheon 21990, South Korea

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. Several flavonoids purified from Kushen were previously
shown to potentiate strongly the BKCa channel. In the present study, the efficacy of Kushen ethanol extracts was

investigated on BKCa channel activity, and voiding function of animal model. A cell-based assay using a hyperactive
BKCa channel and electrophysiology method with oocyte of Xenopus laevis expressing rat BKCa channel was

performed to investigate the potentiating effects of Kushen extracts on BKCa channel function. Efficacy of the
extracts was tested on voiding behavior using the spontaneously hypertensive rats, an overactive bladder animal

model. The Kushen extracts can potently activate the BKCa channel by shifting the conductance-voltage relationship
to more negative voltages. Also, the extracts increased the macroscopic maximum conductance through delayed

the channel closing time. The extracts also can decrease the urination frequency of overactive bladder rat model as
much as, or more than, kurarinone, a potent BKCa channel activator. Therefore, Kushen ethanol extracts can be
developed as nutrient supplements to improve urination activity.