The methanol, n-butanol, chloroform and water extracts obtained from the root of Eurycoma longifolia Jack were assayed using methylene blue assay to evaluate its cytotoxic effect against KB, DU-145, RD, MCF-7, CaOV-3, MDBK cell lines. The results showed that all the root extracts except the water extract of E. longifolia produced significant cytotoxic effect on these cell lines. However, no significant cytotoxic effect was detected on MDBK (kidney) normal cell line. 9-methoxycanthin-6-one, an alkaloid, was detected in each extract with different intensities by reversed-phase high performance liquid chromatography.
Sildenafil and its analogues (tadalafil and vardenafil) are phosphodiesterase type 5 inhibitors used in the treatment of male erectile dysfunction. Some dietary supplements, herbal preparations and food products which claim to enhance male sexual function have been found to be adulterated with these drugs. In this study, a gas chromatograph-mass spectrometer (GC-MS) assay was developed for identification of the drugs. In addition to good and short chromatographic separation that can be achieved within 6 min by using a short 10 m capillary column, no prior sample clean-up before GC-MS analysis was required, thus making this assay a cost saving and rapid method. Furthermore, the assay is specific as the identification of sildenafil, tadalafil and vardenafil were done by detection of molecular ions; m/z 474, 389 and 488, [corrected] respectively, and several other characteristic ions resulted from the mass fragmentation of individual molecules. Using our currently developed assay, sildenafil and its analogues were successfully identified in food and herbal matrices.