MEDICINAL PLANTS AND CYCLIC NUCLEOTIDE PHOSPHODIESTERASE INHIBITORY ACTIVITY

Abstract

Erectile dysfunction is a distressing condition afflicting men of all ages but current treatment options face limitations. Hence, this work aims to investigate the PDE5 inhibitory potential of Swietenia macrophylla and Vitex trifolia, evaluate the in vitro cytotoxicity of S. macrophylla and develop a novel PDE5 inhibition screening method. S. macrophylla possessed more potent PDE5 inhibition than V. trifolia. Subsequent bioassay-guided fractionation of the most active S. macrophylla ethyl acetate maceration extract revealed that subfraction EM5-3 is a promising source for PDE5 inhibitors. In vitro cytotoxicity screening of its extracts, column fractions and selected phytoconstituents demonstrated that only non-polar extracts and fatty acids significantly reduced L02 and Vero cell viabilities at high concentrations. A novel fluorescence polarization-based PDE5 inhibitory screening assay was successfully developed and applied to selected S. macrophylla extracts, fractions, compounds, sildenafil and its analogues. Overall, the findings of this work provide scientific evidence to support the reported use of S. macrophylla in sexual performance enhancement and it represents a step towards the development of novel and effective PDE5 inhibitors