D-004 ameliorates phenylephrine-induced urodynamic changes and increased prostate and bladder oxidative stress in rats

Inhibitory Effect of α1 Receptor Antagonists on Paclitaxel-Induced Peripheral Neuropathy in a Rodent Model and Clinical Database

The anticancer drug, paclitaxel, is widely used for ovarian, breast, non-small cell lung, and gastric cancers; however, it induces peripheral neuropathy as a side effect. There is insufficient evidence-based prophylaxis, and new prophylaxis and treatment methods are required. We examined the effect of α1-receptor antagonists on paclitaxel-induced peripheral neuropathy using Sprague-Dawley rats and a large adverse event database. The repeated administration of doxazosin or tamsulosin significantly reduced the response threshold to paclitaxel administration in animal models. In the sciatic nerve tissue, axonal degeneration and myelopathy were significantly suppressed. Furthermore, an analysis of the Food and Drug Administration Adverse Event Reporting System (FAERS) database suggested that the group using α1 inhibitors showed a lower reporting rate for paclitaxel-related peripheral neuropathy than the group that did not use these inhibitors (odds ratio (95% confidence interval): tamsulosin 0.21 (0.08−0.56), p < 0.01, doxazosin 0.41 (0.10−1.65), p = 0.195; any α1 receptor antagonist 0.54 (0.38−0.76), p < 0.01). Thus, doxazosin and tamsulosin may inhibit the development of paclitaxel-induced peripheral neuropathy by suppressing neurodegeneration, particularly axonal degeneration and myelopathy.

Additive effect of oral LDD175 to tamsulosin and finasteride in a benign prostate hyperplasia rat model

Objective

We investigated the benefits of the BK_Ca agonist 4-chloro-7-trifluoromethyl-10H-benzo[4,5]furo[3,2-b]indole-1-carboxylic acid (LDD175) combined with tamsulosin and finasteride, in a benign prostatic hyperplasia (BPH) rat model.

Materials and methods

Castration was performed by bilateral orchiectomy under ketamine anesthesia. A rat model of BPH was established by daily intramuscular administration of testosterone propionate plus 17β-estradiol for 8 weeks. Model rats were administered combinations of 20 mg/kg LDD175, 0.01 mg/kg tamsulosin and 1 mg/kg finasteride once daily by oral gavage for 4 weeks from week 6 to 9 post-surgery. Intraurethral pressure induced by electrostimulation of the hypogastric nerve was measured at the end of administration. Body and genitourinary organ weights were recorded, serums were assayed for hormone concentrations, and tissues were subjected to histopathology, and analyses of α1-adrenoceptor mRNA and protein expression levels after treatment.

Results

Combined LDD175, tamsulosin, and finasteride significantly decreased prostatic index, serum hormone levels, epithelial thickness, and prostate expression of α1-adrenoceptors in BPH model rats. The 3-drug combination was more effective than any other combination or LDD175 alone.

Conclusion

These results suggest that LDD175 addition to tamsulosin and finasteride may be beneficial for the treatment of BPH patients who do not respond to tamsulosin plus finasteride.