Effect of Total Saponin on Penile Erection: A Combined in Vitro and in Vivo Study

Jung, Hee Chang; Suh, Jun Kyu

Abstract

Korean ginseng (KG) has been used as a general tonic in oriental society The present study was undertaken to elucidate the pharmacologic action and therapeutic effect of KG in penile erection. We observed the effect of total saponin (TS), a major extract of KG, on relaxation of rabbit cavernous smooth muscle as well as rat penile erection, which were compared those of various vasoactive drugs including sodium nitroprusside (SNP), S-nitro-N-acetylpenicillamine (SNAP), L-ethoxycarbonyl-3-morpholinosydnonimine (SIN-1), PGE1, zaprinast. TS (1~4mg/cc) significantly relaxed endothelium-intact, rabbit cavernous strips precont.acted with phenylephrine (10(-6)M) in dose dependent manner (% relaxation: 5.8+/-2.1-36.7+/-5.8%). No significant difference was found in relaxation of deendothelialized cavernous tissue. In comparison of it's relaxing effect with other vasoactive drugs, TS (4mg/cc) was more potent than SIN-1 (10(-3)M), and less potent than SNP (10(-3)M) and SNAP (10(-3)M). Intracavernous injections of TS (0.05mg~3.2mg/0.1cc) induced penile erection (increase of intracavernous pressure: 1.34-21.32mmHg, duration of tumescence: 0.29-5.16 min) in dose dependent manner. In addition, TS did not cause any significant change of systemic blood pressure. In comparison of maximal effect of TS (3.2mg/0.1cc) with other drugs (10(-3)M-10(-4)M), the order of sequence were SNP>SNAP>PGE1>TS>SIN-1>zaprinast. These results indicate that total saponin induces penile erection by relaxing corpus cavernosum, probably in endothelial independent manner. Clinical application of KG require further researches to identify the effective subfraction of total saponin.