To determine the effects of the herbal fixed-dose combination PRO 160/120 ( extracts from saw palmetto fruits and stinging nettle roots ) on nocturnal voiding frequency , as measured by question 7 of the IPSS questionnaire , in patients with moderate-to-severe LUTS/BPH after 24 weeks of treatment compared to placebo , to the - blocker tamsulosin , or to the 5-reductase inhibitor finasteride .