Effects of dutasteride on lower urinary tract symptoms: a prospective analysis based on changes in testosterone/dihydrotestosterone levels and total prostatic volume reduction

Restorative effects of red onion (Allium cepa L.) juice on erectile function after-treatment with 5α-reductase inhibitor in rats

Benign prostatic hyperplasia (BPH) is one of the most prevalent conditions among aged men. The use of 5α-reductase inhibitors (5-ARIs) to treat BPH was linked to erectile dysfunction (ED). Many medicinal plants and secondary metabolites are used in the management of ED. Onion (Allium cepa L.) is an economically affordable vegetable with vital phytochemicals and biological functions. The study aimed to identify the beneficial effects of onion juice on dutasteride (a 5-ARI)-induced ED. Rats were divided into two groups (n = 5 per group): control and dutasteride-treated rats (0.5 mg/kg/day). Dutasteride was administered in drinking water for 12 weeks. Experiments were performed at the end of the 12th week. In vivo erectile responses were measured before and after intracavernosal injection of onion. Relaxant responses to onion juice were examined in the corpus cavernosum (CC). Acetylcholine (ACh)-, electrical field stimulation (EFS)-, sodium nitroprusside (SNP)-induced relaxation responses in CC tissues were evaluated in the absence and presence of onion juice. Total intracavernosal pressure (ICP) and ICP/ mean arterial pressure were significantly reduced in dutasteride-treated rats (1881.14 ± 249.72 mmHg, P < 0.001;0.26 ± 0.03, P < 0.01) as compared to control rats (4542.60 ± 429.19 mmHg, 0.51 ± 0.05), which was normalized after the intracavernous administration of onion (3288.60 ± 185.45 mmHg, 0.58 ± 0.04). Onion markedly induced relaxant responses in control (72.5 ± 4.7) and dutasteride-treated (66.5 ± 2.7) groups after precontraction with phenylephrine. Relaxation responses to onion were partially inhibited after precontraction with KCl (32.5 ± 3.1, P < 0.001). The relaxant responses to ACh (14.9 ± 4.2, P < 0.01) were diminished in dutasteride-treated CC) compared to control CC (59.8 ± 3.4), which was enhanced after the incubation with onion (36.6 ± 4.8). There were no differences in relaxation response to SNP among all groups. However, relaxation response to SNP was reduced in dutasteride-treated CC at 1 μM (P < 0.05) and 10 μM dosages (P < 0.001), which was partially increased after the incubation with onion at 10 μM dosage (P < 0.01). The presence of onion did not change the reduction in EFS-caused relaxation in the dutasteride-treated group. The current data suggest that red onion juice has a restorative effect on erectile function and endothelium-dependent relaxation response following the treatment of dutasteride.

Evaluating how much dutasteride actually reduces serum dihydrotestosterone level: A Reconsideration based on unexpected results from a study of treatment of benign prostatic hyperplasia with dutasteride

Objective:

This study aimed to evaluate the effect of dutasteride treatment of benign prostatic hyperplasia on serum steroidal sex hormones and prostate volume (PV).

Methods:

Thirty patients with benign prostate hyperplasia treated with dutasteride for one year were assessed for changes in PV and serum sex hormones (testosterone (T), dihydotestosterone (DHT), estradiol (E2) and dehydroepiandrosterone sulphate (DHEAS)). PV was measured by ultrasonography. A paired or unpaired t-test and Pearson’s correlation coefficient test were used for statistical analysis.

Results:

DHT and DHEAS decreased by 38.5% and 20.3%, respectively. On the contrary, T and E2 increased by 34.3% and 9.4%, respectively. PV and prostate-specific antigen decreased by 17.7% and 63.4%, respectively. The rate of decrease of DHT had a negative correlation with PV, and the rate of decrease of DHEAS had positive correlation with PV.

Conclusion:

DHT did not decrease as expected (previous studies showed a decrease of approximately 90%). However, DHEAS decreased more than a natural decrease. It is possible that the conversion from DHEAS to DHT, via the conversion to T, in the prostate was accelerated by the decrease of DHT, especially in larger prostates. However, this discrepancy cannot be full explained by the conversion from DHEAS to DHT, as mentioned above.

Level of evidence:

Level 2c

Effects of the dutasteride and sildenafil association in the penis of a benign prostatic hyperplasia animal model

OBJECTIVE

The aim of this study was to investigate whether concomitant treatment of dutasteride and sildenafil could prevent structural changes in the penis of a BPH rodent model.

METHODS

Thirty-two adult male rats were divided into the following groups: Ctrl, untreated control rats; BPH, untreated spontaneously hypertensive rats (SHRs); BPH + D, SHRs treated with dutasteride; and BPH + DS, SHRs treated with dutasteride and sildenafil. All treatments were performed during 40 days, following which the penises were collected for histomorphometrical analysis. The results were compared via one-way ANOVA with Bonferroni's post-test, considering p values <.05 as significant.

RESULTS

The smooth muscle density decreased by 28.6% and 21.4% in BPH + D and BPH + DS, respectively, when compared to the BPH group. The sinusoid space density reduced by 32.2% in BPH, when compared to the Ctrl group; this density was also reduced by 22.6% in BPH + D, when compared to the BPH group. The density of the elastic fibers increased 51.6% and 65.6% in BPH + D and BPH + DS, when compared to the BPH group.

CONCLUSION

Treatment with dutasteride promoted morphological changes in the corpus cavernous of this BPH model. Concomitant treatment with sildenafil did not prevent the morphological changes caused by dutasteride; on the contrary, it also promoted a further increase in elastic fibers.