In vitro pro-apoptotic and anti-migratory effects of Marantodes pumilum (Blume) Kuntze and Ficus deltoidea L. extracts on prostate cancer cell lines

This thesis evaluates the in vitro pro-apoptotic and anti-migratory effects of Marantodes pumilum Blume Kuntze and Ficus deltoidea L. plants on prostate cancer cells, characterising both their mechanism of actions on some of the main Hallmarks of Cancer, and their chemistry with a view to contribute to future chemopreventive strategies. Plant materials of M. pumilum (MP) F. deltoidea var. angustifolia (FD1) and F. deltoidea var. deltoidea (FD2) were obtained from dedicated farms in Southern Malaysia. The crude methanolic extract was partitioned into n-hexane (MPh, FD1h, FD2h) chloroform (MPc, FD1c, FD2c) and aqueous extracts (MPa, FD1a, FD2a). Active fractions (GI50 < 30 μg/mL) based on prostate cancer cell line, PC3, Sulforhodamine B staining were further fractionated. Active compound/s were identified using spectroscopic methods. In vitro mechanistic studies on PC3 cells were conducted to investigate the mode of death of PC3 cells and effects of the active extracts on PC3 cells migration and invasion. MPc, FD1c and FD2c extracts induced cell death via apoptosis as evidenced by nuclear DNA fragmentation, accompanied by a significant increase in MMP depolarization (P < 0.05), activation of caspases 3 and 7 (MPc P < 0.01; FD1c and FD2c P < 0.05) in both PC3 and LNCaP cell lines. All active plant extracts up-regulated Bax and Smac/DIABLO and down-regulated Bcl-2 (P < 0.05). Only MPc inhibited the expression of ALOX-5 mRNA gene expression (P < 0.001). None resulted cytotoxic against normal human fibroblast cells (HDFa) at the tested concentrations. All active plant extracts inhibited both migration and invasion of PC3 cells (MPc; P < 0.01, FD1c and FD2c; P < 0.05), achieved by down-regulation of both VEGF and CXCL-12 gene expressions (P < 0.001). A monounsaturated 5-alkyl resorcinol was isolated as the active compound present in the MPc extract. LC-MS dereplication identified isovitexin in FD1c; and oleanolic acid, moretenol, betulin, lupenone and lupeol in FD2c. In conclusion, evidence gathered in this study suggests a role for interaction of MPc, FD1c and FD2c in three of the Hallmarks of Cancer in PC3 cells: (1) apoptosis by activating of the intrinsic pathway, (2) inhibition of both migration and invasion by modulating the CXCL12-CXCR4 axis, and (3) inhibiting angiogenesis by modulating VEGF-A expression. The compounds identified and dereplicated in this study will be further characterized and used for the standardization of the active extracts in the future.