Objective: To study the relaxants effects of six extractions from Chinese Herbs (neferine, tetrandrine, kakonein, scutellarin, ginsenoside Rgl and ginsenoside Rb1) on the corpus cavernosum tissue of rabbit in vitro.
Methods: Isolated stripes of rabbit corpus cavernosum tissue were precontracted with 10(-5) mol/L phenylephrine (PE). Relaxation in response to cumulative doses of six extracts at (10(-8) - 10(-3)) mol/L was determined.
Results: On rabbit cavernosal muscle stripes precontracted with PE, neferine, tetrandrine, kakonein and scutellarin showed dose dependent relaxation. IC50 values were 4.60 x 10(-6), 3.73 x 10(-5), 8.03 x 10(-4) and 3.33 x 10(-3) mol/L, respectively. However, in the meantime, it was found that the relaxant effects of ginsenoside Rgl and ginsenoside Rbl less significant to stripes precontracted with PE. When the final concentration was 10(-3) mol/L, the relaxations were only (16.32 +/- 5.45)% and (11.21 +/- 3.10)%.
Conclusion: Among the six extracts which showed relaxant effects to rabbit cavernosal muscle stripes precontracted with PE, neferine had greater functions than the other five extracts.