Researchers at the College of Veterinary Medicine, Chungbuk National University, Heungdeok-gu, Cheongju, Chungbuk, Korea, examined the effects of trans-resveratrol on male reproductive functions: ex-vivo penile erection and in-vivo sperm counts and quality. Resveratrol is one of the most commonly employed dietary polyphenols.

For the ex-vivo study, the relaxation effects of resveratrol on isolated New Zealand white rabbit corpus cavernosum, precontracted by phenylephrine (5x10(-5) M) were measured.

The in-vivo study measured reproductive organ weights, blood testosterone levels, testicular histopathology, sperm counts, as well as the epididymal sperm motility and deformity of male ICR mice given an oral dose of resveratrol (50 mg/ kg) for 28 days.

Resveratrol elicited a concentration-dependent relaxing effect on corpus cavernosum, leading to a median effective concentration (EC50) of 0.29 mg/mL. Repeated treatment with resveratrol (50 mg/kg) did not cause an increase in body weight, reproductive organ weight or testicular microscopic findings; however, resveratrol did elicit an increase in blood testosterone concentration, testicular sperm counts and epididymal sperm motility by 51.6%, 15.8% and 23.3%, respectively, without influence on sperm deformity.

In conclusion, researchers propose that resveratrol has a positive effect on male reproductive function by triggering a penile erection, as well as enhancing blood testosterone levels, testicular sperm counts, and epididymal sperm motility.

The aim of a new study was to evaluate the relaxant effect of resveratrol (RVT) in rat corpus cavernosum, and to further investigate the contribution of possible underlying mechanisms.

The results demonstrated that RVT has a potent relaxant effect on rat corpus cavernosum via endothelium-dependent and -independent mechanisms.
Endothelium-dependent relaxation of corpus cavernosum to resveratrol is thought to be mediated primarily through NO/cGMP signaling pathway, and possibly an additional mechanism, endothelium-dependent hyperpolarization factor (EDHF). The residual endothelium-independent corpus cavernosum relaxation induced by RVT is uncertain but seems to depend on the interactions of RVT with Ca(2+) entry mechanism from the extracellular space and also other undefined direct effects in this tissue.

For more information
http://www.ncbi.nlm.nih.gov/pubmed/18277612

http://www.ncbi.nlm.nih.gov/pubmed/23466662

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