ABSTRACT
PURPOSE: Ginseng has been used throughout the Far East, including Korea and China, as a tonic and restorative agent to maintain physical vitality. The main pharmacoactive molecules of ginseng are ginsenosides. The present study was designed to investigate whether ginsenosides relax rabbit vaginal smooth muscle and whether this effect is modulated by nitric oxide(NO) and the cGMP pathway. MATERIALS AND METHODS: Strips of rabbit vagina were mounted in organ chambers to measure isometric tension. The strips were contracted with phenylephrine(5 X 10(-5) M), and the responses to acetylcholine, nitric oxide inhibitor, and ginsenosides were examined. The cGMP content of the strips was measured by radioimmunoassay after various doses of ginsenosides. RESULTS: Ginsenosides(100~500microgram/mL) relaxed vaginal smooth muscle in a dose-dependent manner(5~25%). Acetylcholine-induced relaxation was significantly increased in the presence of ginsenosides(100, 200microgram/mL)(p0.05). Ginsenosides(400microgram/mL for 7 min) increased the accumulation of cGMP. CONCLUSIONS: These data suggest that ginsenosides have a relaxing effect on rabbit vaginal smooth muscle. This effect is at least in part mediated by the NO-cGMP pathway.