Abstract

Background: Obstructive Bladder Dysfunction (OBD) secondary to Benign Prostatic Hyperplasia (BPH) is a major bladder dysfunction in men. The incidence increases with age. Oxidative stress is a major factor OBD and specific natural products with significant antioxidant activity have proven to be useful in its treatment. Specifically in an in-vivo model of Ischemia/Reperfusion (I/R) of the rabbit urinary bladder Gannoderma Lucidum (GL) have been shown to be effective in the treatment of oxidative stress. The specific aim of the current study is to determine if GL is effective in the treatment of oxidative stress using an in-vitro model of I/R of the rabbit urinary bladder.

Methods: Eight NZW rabbits were divided into 2 groups. One group was fed Ganoderma Lucidum (GL) (100 mg/Kg) daily for 3 weeks while the other were controls. At the end of the 3 week period, each rabbit was euthanized and the bladder separated into six strips and mounted in individual baths. Each strip was stimulated with Field Stimulation (FS), Carbachol, potassium chloride (KCl), and adenosine triphosphate (ATP). After the control stimulations, the oxygenated baths were subjected to nitrogen in the absence of glucose (ischemia) for 1 hour while being stimulated at 32Hz at 5 minute intervals. After 1 hour of ischemia, the buffer was changed back to normal oxygenated Tyrode's with glucose and allowed to recover for 2 hours. After this time period, the strips were stimulated as described earlier.

Results: 1) There was a rapid and near complete inhibition of the contractile responses during the ischemic period for both control and GL groups; 2) For the control group, following I/R there was a 86% decrease in the response to FS, 11% decrease in the response to ATP, 17% decrease in the response to carbachol, and 20% decrease in the response to KCl. For the GL group, there was a 71% decrease in the response to FS, and no decreases in the responses to ATP, carbachol, or KCl.

Conclusion: Pretreatment of rabbits for three weeks with GL prior to subjecting them to in-vitro ischemia/reperfusion significantly protected the bladder strips from all forms of contractile dysfunctions, although the response to FS was still significantly decreased.

Keywords: Ganoderma lucidum, oxidative stress, anti-ageing, rabbits, urinary bladder, obstructive bladder dysfunction.

Graphical Abstract