title: Erectogenic Effects of Clerodendron capitatum: Involvement of Phosphodiesterase Type-5 Inhibition.
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.
authors: Faculty of Medicine, University of Malaya, Petaling Jaya, Kuala Lumpur 50603, Malaysia.
authors: Siddig Ibrahim
authors: SI
authors: Abdelwahab
authors: Abdelwahab Hassan
authors: AH
authors: Mohamed
authors: Osama Yousif
authors: OY
authors: Mohamed
authors: Mahjoub
authors: M
authors: Oall
authors: Manal Mohamed Elhassan
authors: MM
authors: Taha
authors: Syam
authors: S
authors: Mohan
authors: Mohamed Ibrahim
authors: MI
authors: Noordin
authors: Mohd Rais
authors: MR
authors: Mustafa
authors: Khalid M
authors: KM
authors: Alkharfy