Functional evaluation of tadenan on micturition and experimental prostate growth induced with exogenous dihydrotestosterone

Objectives. To evaluate the effect of Tadenan (TAD; Pygeum africanum extrac t) pretreatment on the micturition characteristics of conscious and anesthe tized rats consequent to dihydrotestosterone (DHT) administration and to ex amine the influence of such treatment on the growth of the prostate. Methods. Studies using 40 adult Sprague-Dawley male rats were performed dur ing a 7-week period. These animals were treated with DHT 1.25 mg/kg subcuta neously dissolved in peanut oil and/or TAD 100 mg/kg orally dissolved in se same oil, except for the controls, which received vehicle only. Rats were d ivided into four groups: group 1 (control), vehicle only; group 2, DHT admi nistered during weeks 3 and 4; group 3, TAD pretreatment, administered duri ng weeks 1 and 2, followed by the combined administration of DHT and TAD du ring weeks 5 and 4 and TAD only during weeks 5 to 7; and group 4, continuou s TAD treatment for 7 weeks. Micturition of conscious rats was evaluated in metabolic chambers, and in anesthetized rats, cystometrograms were done at the end of 7 weeks. Results. DHT or DHT plus TAD did not produce significant changes in the vol ume but did reduce the frequency of micturition. TAD given alone significan tly increased the volume of micturition and the rate of urine production. C ystometrographic studies in anesthetized rats revealed that DHT produced mi cturition characteristics similar to obstruction. The DHT plus TAD and TAD pretreatment data showed no significant difference from controls, suggestin g that in the presence of TAD, the effects of DHT were negated. The total p rostate weight of DHT and DHT plus TAD pretreated rats increased, and in th e TAD group, these values decreased to lower than controls; growth of the v entral lobes was suppressed in the presence of TAD. Conclusions. These results demonstrate that TAD pretreatment significantly reduces the "obstructive" effects of DHT on micturition, counteracts the ho rmone-induced enlargement of the prostate, and reduces prostate weight in t he ventral but not the dorsal robe. (C) 2000, Elsevier Science Inc.