The effect of Korean red ginseng extract on the relaxation response in isolated rabbit vaginal tissue and its mechanism.
BACKGROUND
Ginseng is an herbal medicine with a variety of biological activities.


OBJECTIVE
The purpose of this study was to investigate the effect of Korean red ginseng (KRG) extract on the relaxation response in isolated rabbit vaginal tissue and its mechanism as a potential therapeutic agent for female sexual dysfunction.


METHODS
Strips of rabbit vagina were mounted in organ chambers to measure isometric tension. After the strips were precontracted with phenylephrine, the contractile responses to KRG extract (1-20 mg/mL), nitric oxide inhibitor (N[omega]-nitro-L-arginine methyl ester [L-NAME]), an inhibitor of soluble guanylate cyclase (methylene blue), an inhibitor of Ca(2+)-activated K(+) channels (tetraethylammonium [TEA]), and an adenosine triphosphate (ATP)-sensitive K(+) channel blocker (glybenclamide) were examined.


METHODS
The relaxation of the vaginal tissue strip was assessed after treating KRG extract or other chemicals.


RESULTS
KRG (1-20 mg/mL) extract relaxed the vaginal tissue strip in a dose-dependent manner up to 85%. The relaxation effect was significantly inhibited by L-NAME (30 microM) and methylene blue (30 microM) (P < 0.05). In addition, KRG inhibited the contraction induced by depolarization with 10, 20, and 40 mM KCl. The KRG-induced relaxation effect was significantly inhibited by TEA (300 microM) (P < 0.05), and not by glybenclamide (30 microM).


CONCLUSIONS
These data show that KRG extract has a relaxing effect on rabbit vaginal smooth muscle tissue. These effects might be mediated partly through the NO pathway and hyperpolarization via Ca(2+)-activated K(+) channels.
Kim
Sun-Ouck
SO
Department of Urology, Chonnam National University Medical School, Gwangju, Korea.
Kim
Min Kyung
MK
Lee
Hyun-Suk
HS
Park
Jong Kwan
JK
Park
Kwangsung
K
D000818:Animals; D004305:Dose-Response Relationship, Drug; D005260:Female; D006162:Guanylate Cyclase / Q000502:physiology; D009126:Muscle Relaxation / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D009569:Nitric Oxide / Q000502:physiology; D005894:Panax; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology*; D024681:Potassium Channels, Calcium-Activated / Q000187:drug effects / Q000502:physiology; D011817:Rabbits; D014621:Vagina / Q000187:drug effects*
D010936:Plant Extracts; D024681:Potassium Channels, Calcium-Activated; D009569:Nitric Oxide; D006162:Guanylate Cyclase