OBJECTIVES: To investigate the effect of St John's wort (SJW) and its active constituents hypericin and hyperforin on detrusor smooth muscle contractility and their possible neuroprotective role against ischaemic-like conditions, which could arise during overactive bladder disease.
METHODS: In whole bladders, intrinsic nerves underwent electrical field stimulation (EFS). The effect of drugs on the contractile response and its recovery in reperfusion phase (R) was monitored at different concentrations during 1 or 2 h of anoxia-glucopenia (A-G) and the first 30 min of R. The effects of the drugs were also investigated on rat detrusor muscle strips contracted with carbachol, KCl and electrically.
KEY FINDINGS: SJW has spasmolytic activity, which increases with increasing concentration and it worsens the damage induced by A-G/R on rat urinary bladder. Hypericin and hyperforin had no effect during ischemic-like conditions but they both exert a dual modulation of rat detrusor strips contraction. At high micromolar concentrations they showed a relaxing effect, but at submicromolar range hypericin increased the plasma membrane depolarisation and hyperforin showed a stimulatory effect on the cholinergic system.
CONCLUSIONS: The results of our study showed that SJW and its constituents could modulate urinary bladder contractility and even worsen A-G/R injury.
Written by:
Valeri A, Capasso R, Valoti M, Pessina F. Are you the author?
Clinica San Carlo, Milano, Italy.
Reference: J Pharm Pharmacol. 2012 Dec;64(12):1770-6.
doi: 10.1111/j.2042-7158.2012.01556.x
PubMed Abstract
PMID: 23146040
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