Screening Antitumor Compounds Psoralen and Isopsoralen from Psoralea corylifolia Seeds
Psoralea corylifolia (bu gu zhi) is a widely used medical plant in China. A study was designed to screen and identify bioactive compounds with anticancer activity from the seeds of Psoralea corylifolia L. One volatile fraction (fraction I) and three other fractions (fraction II, III, IV) from methanol extraction of P. corylifolia L. were obtained. Bioactivities of these fractions were evaluated by the cytotoxicity on KB, KBv200, K562, K562/ADM cancer cells with MTT assay. Major components in the active fraction were identified by HPLC/MSn. Fraction IV significantly inhibits the growth of cancer cells in a dose-dependent manner. The IC50 values were 21.6, 24.4, 10.0 and 26.9, respectively. Psoralen and isopsoralen, isolated from fraction IV, were subject to bioactive assay and presented a dose-dependent anticancer activity in four cancer cell lines (KB, KBv200, K562 and K562/ADM). The IC50 values of psoralen were 88.1, 86.6, 24.4 and 62.6, which of isopsoralen were 61.9, 49.4, 49.6 and 72.0, respectively. Apoptosis of tumor cell significantly increased after treated with psoralen and isopsoralen. Induction of apoptotic activity was confirmed by flow cytometry after staining with Annexin V/PI. These results suggested psoralen and isopsoralen contribute to anticancer effect of P. corylifolia.
The study showed that psoralen and isopsoralen induced cancer cell apoptosis. Cell apoptosis is mediated by many factors. P53 is a transcription factor at the pivot of a number of pathways that mediate apoptosis in response to a variety of cellular stresses . The differences of apoptotic response to psoralen and isopsoralen may provide some information such as whether or not the induction of apoptosis of P. corylifolia L. extract is dependent on p53.
Wang Y, Hong Ct, Zhou Cg, et al. Screening Antitumor Compounds Psoralen and Isopsoralen from Psoralea corylifolia L. Seeds. Evidence-Based Complementary and Alternative Medicine. Volume 2011 (2011), Article ID 363052, doi:10.1093/ecam/nen087
M. Arkin, “Protein-protein interactions and cancer: small molecules going in for the kill,” Current Opinion in Chemical Biology, vol. 9, no. 3, pp. 317–324, 2005.