Ameliorative effect of cranberry on erectile function in diabetic rats

Background and Aims: Cranberry products are beneficial in erectile dysfunction (ED). Therefore, we assessed the impact of Cranberry fruit extract (Cranberry-E) on in vivo erectile response and in vitro relaxant responses in the corpus cavernosum (CC).Methods: Rats (n=10) were divided into control and diabetic groups. In vivo erectile function was measured following intracavernosal injection of Cranberry-E. The relaxation responses to Cranberry-E were obtained after pre-contraction with phenylephrine (Phe, 10 mu M) and KCl (60 mM). Cranberry-E caused relaxant responses in the incubation with nitric oxide synthase (NOS) blocker (L-NAME, 100 mu M) and soluble guanylate cyclase (sGC) blocker (ODQ, 30 mu M), and relaxation responses of cavernosal tissue were calculated before and after the incubation with Cranberry-E.Results: Erectile responses were significantly reduced in diabetic animals as compared to controls (p<0.001), which was normalized after the intracavernous administration of Cranberry-E. There was no difference in the relaxation responses to Cranberry-E between the control and diabetic groups. Cranberry-E induced the relaxation of cavernosal tissue, which remained unaltered in the presence of L-NAME and ODQ. Relaxation responses to Cranberry decreased after KCl-induced precontraction (p<0.001). The relaxation of cavernosal tissue increased after Cranberry-E incubation.Conclusion: Cranberry-E improved diabetes-induced ED and induced relaxation of cavernosal tissue via a nitric oxide-independent mechanism. Thus, cranberry consumption is likely to be effective as a potential strategy to prevent diabetes-induced ED.