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Updated: May 31, 2026

Treatment Model for Young Patients with Psychogenic Erectile Dysfunction and Resultant Infertility
Published on: May 30, 2025
Erectogenic Effects of Clerodendron capitatum: Involvement of Phosphodiesterase Type-5 Inhibition
Siddig Ibrahim Abdelwahab1, Abdelwahab Hassan Mohamed, Osama Yousif Mohamed
1Faculty of Medicine, University of Malaya, Petaling Jaya, Kuala Lumpur 50603, Malaysia.
Abstract:
Clerodendron capitatum (Willd) (family: verbenaceae) is locally named as Gung and used traditionally to treat erectile dysfunction. Therefore, the current study was designed to investigate the erectogenic properties of C. capitatum. The relaxation effect of this plant was tested on phenylephrine precontracted rabbit corpus cavernosum smooth muscle (CCSM). The effects of C. capitatum were also examined on isolated Guinea pig atria alone, in the presence of calcium chloride (Ca(2+) channel blocker), atropine (cholinergic blocker), and glibenclamide (ATP-sensitive K(+) channel blocker). These effects were confirmed on isolated rabbit aortic strips. The extract, when tested colorimetrically for its inhibitory activities on phosphordiesterase-5 (PDE-5) in vitro towards p-nitrophenyl phenyl phosphate (PNPPP), was observed to induce significant dose-dependent inhibition of PDE-5, with an ID(50) of 0.161 mg/ml (P < .05). In conclusion, our results suggest that C. capitatum possesses a relaxant effect on CCSM, which is attributable to the inhibition of PDE-5, but not mediated by the release calcium, activation of adrenergic or cholinergic receptors, or the activation of potassium channels.
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