In Vivo and in Vitro Animal Investigation of the Effect of a Mixture of Herbal Extracts from Tribulus terrestris and Cornus officinalis on Penile Erection

Abstract

Introduction Herbal preparations have long been used as folk remedies for erectile dysfunction (ED). Aim This study examined the effects of Tribulus terrestris and Cornus officinalis extracts on relaxation of the smooth muscle of the corpus cavernosum (CC), their mechanisms of action, and the effects of oral administration of a mixture of the herbal extracts on penile erection. Methods The relaxation effects and the mechanisms of action of T. terrestris extract, C. officinalis extract, and the mixture of both extracts on the rabbit CC were investigated in an organ bath. To evaluate whether the relaxation response of the CC shown in an organ bath occurs in vivo, intracavernous pressure (ICP) was calculated in rats after oral administration for a month. Additionally, adenosine 3′,5′-cyclic monophosphate (cAMP) and guanosine 3′, 5′-cyclic monophosphate (cGMP) in the CC were measured using immunoassay. Main Outcome Measures Smooth muscle relaxation was expressed as the percent decrease in precontraction induced by phenylephrine. ICP was assessed in rats after the oral administration of a mixture of both extracts for 1 month and changes in cGMP and cAMP concentrations were measured based on the concentration of the mixture of both extracts. Results T. terrestris extract, C. officinalis extract, and the mixture of both extracts showed concentration-dependent relaxation effects of the CC. In both the endothelium-removed group and N(G)-nitro-L-arginine methyl ester pretreatment group, T. terrestris extract inhibited relaxation. ICP measured after oral administration of the extract mixture for a month was higher than that measured in the control group, and a significant increase in cAMP was observed in the mixture group. Conclusions T. terrestris extract and C. officinalis extract exhibited concentration-dependent relaxation in an organ bath. In the in vivo study of the extract mixture, ICP and cAMP was significantly potentiated. Accordingly, the mixture of T. terrestris extract and C. officinalis extract may improve erectile function.

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

“…Tribulus terrestris extract and Cornus officinalis extract demonstrated concentration-dependent relaxation in an organ bath. In an in vivo study of the extract mixture, intracavernous pressure was improved and the cAMP pathway was significantly potentiated [ 44 ].…”

Prospective Analysis on the Effect of Botanical Medicine (Tribulus terrestris) on Serum Testosterone Level and Semen Parameters in Males with Unexplained Infertility

“…In order to confirm the hypothesis for the specificity of nitric oxide-dependent mechanism, they showed that the relaxation of CC strips by Tribulus terrestris was unsuppressed by pretreatment with a variety of other procontractile agents, including indomethacin, glibenclamide, 4-aminopyridine, and ormethyleneblue. Furthermore, the relaxation effect of Tribulus terrestris on corpus cavernosum correlated nicely with increased intra-cavernosal pressure in rats (n 1/4 = 8) measured after treatment with Tribulus terrestris for one month (Kam et al, 2012). Eventually, a study performed in 2014 did not find any beneficial effect of this compound as a pro-sexual drug in erectile dysfunction (Santos et al, 2014).…”

“…Noteworthy is the fact that the same team's work evaluated the role of Tribulus terrestris in male infertility, yet it did not deliver significant results. In the same context, several studies demonstrated an enhancing role of Tribulus terrestris as an ingredient of an herbal mixture in erectile dysfunction (Gauthaman & Adaikan, 2005;Kam et al, 2012).…”

AlgaEcklonia bicyclis,Tribulus terrestris, and Glucosamine Oligosaccharide Improve Erectile Function, Sexual Quality of Life, and Ejaculation Function in Patients with Moderate Mild-Moderate Erectile Dysfunction: A Prospective, Randomized, Placebo-Controlled, Single-Blinded Study

“…T. terrestris extract, C. officinalis extract, and the mixture of both extracts showed concentration-dependent relaxation effects of the corpus cavernosum. Therefore, endothelium appears to be an important location of action of T. terrestris extract, functioning in relaxation mainly via NOS and exhibited relaxation effects mainly through cAMP and partly through cGMP [26]. …”