Fig. 2

Illustration of possible intervention mechanisms of medicinal plants and natural products on OAB in the urinary bladder. a Promotion of the NO synthesis and release. b Reduction of the ATP synthesis and release. c Inhibition of the expression of the M receptors. d Up-regulation of the expression of the adrenergic receptors. e Down-regulation of the expression of P2X receptors. f Inhibition of transmembrane Ca²⁺ influx and stimulation of Ca²⁺ release from intracellular stores. g Activation of K⁺ channels. h Inhibition of TRP channels. i Improvement in the barrier function of urothelium. j Regulation of excess blood flow. k Increase in intracellular cAMP in the bladder smooth muscles. l Inhibition of the release of inflammatory mediators, such as Substance P, CGRP etc.