Elevation of intracavernous pressure and NO-cGMP activity by a new herbal formula in penile tissues of spontaneous hypertensive male rats

Aim of the study: We created a new herbal formulation that mainly consists of the seeds of Lycium chinense. Cornus officinalis, Rubus coreanus, Cuscuta chinensis and Schizandra chinensis. These materials have been long used by Korean people as they are known to be good for health and sexual function; hence we Could say that their safety have been proven in a certain sense. We investigated the effects of this herbal formulation on the penile erection and corpus cavernosum of spontaneous hypertensive male Rats (SHRs). Materials and methods: We used male SHRs aged 16 weeks as a model of hypertension. The treatment groups received once a day oral doses of KH-204 at either 100 or 300 mg/kg per day for 4 weeks. Distilled water was administered to the control group. To investigate the penile erection, the intracavernosal pressure (ICP) and mean arterial pressure (MAP) were recorded in all groups. We analyzed the distribution of NOS by immunohistochemical staining and the expressions of nNOS and eNOS in the isolated corpus cavernosum were measured by Western blotting. Results: In the control group, the ICP/MAP ratio was 14.9 +/- 1.4% after pelvic nerve stimulation. The ICP/MAP ratio was markedly increased in the treatment group with KH-204 100 or 300 mg/kg, compared with the control group. Immunohistochemical staining for NOS showed that eNOS and nNOS were stained as a brown color. Compared with the control group, the NOS activities of KH-204 100 or 300 mg/kg were significantly increased. Also, the penile expression levels of nNOS and eNOS in the KH-204 100 and 300 mg/kg treatment groups were more increased, and this was significant, than those of the control group, as was determined by Western blotting. Conclusions: This study showed that the KH-204 herbal formulation enhances intracavernous pressure and NO-cGMP activity in penile tissues of SHR male rats. (C) 2008 Elsevier Ireland Ltd. All rights reserved.