The Open Conference Proceedings Journal

2013, 4 : 88-88
Published online 2013 March 1. DOI: 10.2174/2210289201304010088
Publisher ID: TOPROCJ-4-4-88

wall. Ex Baker: A Source of PDE5 Inhibitors

Prapapan Temkitthawon , Thomas R. Hinds , Joseph A. Beavo , Jarupa Viyoch , Khanit Suwanborirux , Pattara Sawasdee and Kornkanok Ingkaninan
Department of Pharmaceutical Chemistry and Pharmacognosy and Center of Excellence for Innovation in Chemistry, Faculty of Pharmaceutical Sciences, Naresuan University, Phitsanulok 65000, Thailand;.

ABSTRACT

Kaempferia parviflora Wall. ex Baker has been popularly used as male sexual performance enhancer in Thailand. However, its mechanisms were still unknown. One of the possible mechanism for this remedy is phosphodiesterase 5 (PDE5) inhibition. Among 41 plant extracts, the rhizomes of K. parviflora ethanolic extract could inhibit PDE5 at 50 μg/ml. Therefore, eight 7- methoxyflavones which are the major the chemical constituents isolated from rhizomes of K. parviflora were further investigated on inhibitory activity against PDE5. Moreover, the selectivity of these compounds on PDE5 over PDE6 was evaluated. The results showed that 7-methoxyflavones from this plant showed inhibition effect toward both enzymes. The most potent PDE5 inhibitor was 5,7-dimethoxyflavone (IC50=10.64±2.09 μM, selectivity on PDE5 over PDE6 = 3.71). Structure activity relationship showed that the methoxyl group at C-5 position of 7-methoxyflavones was necessary for PDE5 inhibition. K. parviflora rhizome extract and its 7-methoxyflavone constituents had moderate inhibitory activity against PDE5. This finding provides an explanation for enhancing sexual performance in the traditional use of K. parviflora. Moreover, 5,7- dimethoxyflavones could be a useful lead compound for clinically efficacious PDE5 inhibitors.

Keywords:

, phosphodiesterase5, traditional sexual performance enhancer.