The effect of unripe Rubus coreanus extract on rabbit penile corpus cavernosum (PCC) was evaluated. Penises were obtained from healthy male New Zealand white rabbits (2.5-3.0 kg). The pre-contracted penis with phenylephrine (Phe, 10 μM) was treated with various concentrations of an extract of unripe R. coreanus (0.5, 1, 2, 3 and 4 mg/mL). The change in penile tension was recorded, cyclic nucleotides in the perfusate and the PCC were measured by radioimmunoassay, and the expression of neuronal nitric oxide synthase (nNOS) and endothelial nitric oxide synthase (eNOS) in the perfused PCC were measured by western blotting. The interaction between unripe R. coreanus and sildenafil was also evaluated. The PCC relaxation induced by the extracts of R. coreanus was in a concentration-dependent manner and enhanced sildenafil-induced PCC relaxation. The perfusion of penile cavernous tissue with the unripe R. coreanus extract increased cGMP and cAMP in the tissue and in the perfusate and the expression of eNOS and nNOS in the tissue. The unripe R. coreanus extract exerts a relaxing effectonpenile cavernous tissueinpartbyactivating the NO-cGMP system and itmay improve erectile dysfunction (ED), which does not completely respond to sildenafil citrate.
- NO-cGMP system
- Penile corpus cavernosum (PCC)
- Penile perfusion model
- Rubus coreanus