Screening for PDE inhibitory activity from Thai traditional plants used as rejuvenating and aphrodisiac agents

Abstract

Phosphodiesterase (PDEs) [1, 2], are a group of enzymes that have powerful effect on cellular signal because they regulate the second messengers, cAMP or cGMP. PDEs inhibitors have been used for treatment in many indications such as cardiovascular disease, chronic obstructive pulmonary disease and erectile dysfunction. In our studies, more than twenty of Thai traditional plants used as rejuvenating and aphrodisiac agents were collected. The plant ethanolic extracts were tested for PDE inhibitory activity using malachite green assay [3] in 96-welled microplates. The amount of phosphate which was liberated from the enzymatic reaction was from a complex with malachite green reagent and showed the absorbtion at 640 nm. The results showed that ethanolic extracts of Ficus pubigera Wall. (Ma-kra-thuep-rong) and Piper spp. (Sakhan-dang) at concentration 1mg/mL inhibited more than 80% and 70% of PDE activity, respectively.