Effects of Ginkgo biloba extracts with mirodenafil on the relaxation of corpus cavernosal smooth muscle and the potassium channel activity of corporal smooth muscle cells

Abstract

In this study, we investigated the effects of a combination of Ginkgo biloba extracts (GBE) and phosphodiesterase type 5 (PDE-5) inhibitors on the muscular tone of the corpus cavernosum and potassium channel activity of corporal smooth muscle cells. Strips of corpus cavernosum from male New Zealand white rabbits were mounted in organ baths for isometric tension studies. After contraction with 1310 25 mol l 21 norepinephrine, GBE (0.01-1 mg ml 21 ) and mirodenafil (0.01-100 nmol l 21 ) were added together into the organ bath. In electrophysiological studies, whole-cell currents were recorded by the conventional patch-clamp technique in cultured smooth muscle cells of the human corpus cavernosum. The corpus cavernosum was relaxed in response to GBE in a dose-dependent manner (from 0.64%68.35% at 0.01 mg ml 21 to 52.28%611.42% at 1 mg ml 21 ). After pre-treatment with 0.03 mg ml 21 of GBE, the relaxant effects of mirodenafil were increased at all concentrations. After tetraethylammonium (TEA) (1 mmol l 21 ) administration, the increased effects were inhibited (P,0.01). Extracellular administration of GBE increased the whole-cell K 1 outward currents in a dose-dependent fashion. The increase of the outward current was inhibited by 1 mmol l 21 TEA. These results suggest that GBE could increase the relaxant potency of mirodenafil even at a minimally effective dose. The K 1 flow through potassium channels might be one of the mechanisms involved in this synergistic relaxation.

Effects of Korean ginseng berry extract (GB0710) on penile erection: evidence from in vitro and in vivo studies

“…[13][14][15] A recent systematic review of randomized clinical trials revealed that Panax ginseng improves glucose metabolism and moderates the immune response. 16 KRG is also used as a tonic to maintain physical vitality and for restorative purposes throughout East Asian countries, including Korea and China.…”

Castration impairs erectile organ structure and function by inhibiting autophagy and promoting apoptosis of corpus cavernosum smooth muscle cells in rats

“…Fifteen rats in each group were used for the corpus cavernosum strip bath test, as described previously [20][21][22][23][24]. Two corporal strips of approximately equal size (1 × 1 × 5 mm) were obtained from each penis.…”

Current Status and Clinical Studies of Oriental Herbs in Sexual Medicine in Korea

“…G. biloba induced the relaxation of the corpus cavernosum in a dose-dependent manner and also effectively increased the relaxant potency of mirodenafil in rabbit corpus cavernosum tissue, even at the minimal effective dose [ 22 ].…”