To evaluate the effect of Pueraria mirifica on vaginal and urethral cytology, bladder pressure and capacity, residual urine, and leak point pressure in ovariectomized rats.
Seventy-two adult, ovariectomized, female Sprague-Dawley rats were placed into one of four groups: control, estradiol, or 100 or 1,000 mg/kg of Pueraria mirifica (PM-100 and PM-1000, respectively). The vaginal and urethral smears were checked after 30 days of ovariectomy at pretreatment and at day 28 of treatment.
A single cystometry, defined as the micturition interval, filling pressure, threshold pressure, micturition pressure, and voided volume, was performed. Peak bladder pressure was calculated for each leak point pressure measured at half bladder capacity by slowly and manually increasing abdominal pressure until a leak occurred, at which point external pressure was rapidly released. Leak point pressure was tested three times per rat.
After 28 days of treatment, the estradiol, PM-100, and PM-1000 groups had significantly higher numbers of vaginal and urethral superficial cells compared with the control group (P < 0.05). Regarding the urodynamic parameters, the threshold pressure, micturition pressure, and leak point pressure were higher in the estradiol, PM-100, and PM-1000 groups compared with the control group (P < 0.05). The control, PM-100, and PM-1000 groups had the same values for micturition interval, bladder capacity, voided volume, and residual volume (P > 0.05) but lower values compared with the estradiol group (P < 0.05).
Pueraria mirifica 100 and 1,000 mg/kg/day showed an estrogen-like effect on the vaginal and urethral epithelium of ovariectomized rats. They did not change bladder capacity and residual urine volume but increased leak point pressure according to urodynamic study.