Authors:	Wu, Ching-Fen
Title:	Molecular mechanisms and pharmacogenomics of constituents of Salvia miltiorrhiza for anticancer therapy
Online publication date:	26-Apr-2016
Year of first publication:	2016
Language:	english
Abstract:	Cancer is a worldwide public health problem. Owing to severe side effects and development of resistance, new anticancer agents are urgently required. Natural products provide novel options, because they are considered as being less toxic and more active by multifactorial mechanisms. Salvia miltiorrhiza Bunge (Lamiaceae), Danshen in Chinese, is a well-known traditional herb widely used in China. In addition to its activity against cardiovascular diseases, recent reports also focused on the anticancer effects this plant. In this thesis, I hypothesized that S. miltiorrhiza can bypass drug resistance. I investigated molecular mechanisms underlying cytotoxic effects of the extract and three main chemical compounds of S. miltiorrhiza. The root extract of S. miltiorrhiza exerted profound cytotoxicity towards various sensitive and multidrug-resistant, P-glycoprotein over-expressing CEM/ADR5000 leukemia cells, EGFR transfected U87.MGΔEGFR glioblastoma cells and HCT-116 p53-knockout colon cancer cells. The plant extract activated the intrinsic apoptotic pathway, which was experimentally determined by increased cleavage of caspase 3, 7, 9 and poly ADP-ribose polymerase (PARP). Further in vitro studies revealed that cryptotanshinone and miltirone as main constituents of S. miltiorrhiza induced the intrinsic apoptotic pathway, G2/M cell cycle arrest, DNA damage, as well as the generation of reactive oxygen species (ROS). Furthermore, signaling of the transcription factor NFκB and cellular movement has been inhibited. These effects have been unraveled by transcriptome-wide microarray-based mRNA expression. Bioinformatic analyses of microarray results also showed that unfolded protein response (UPR) and eIF-mediated translation initiation, which determine cancer cell fate and which are recognized as anticancer targets, were regulated by cryptotanshinone. Rosmarinic acid induced apoptosis and necrosis by pathways, which were ROS-, DNA damage and caspase-independent. Molecular docking and Western blotting provided supportive evidence suggesting that cryptotanshinone, miltirone and rosmarinic acid bound to IKK-κ and inhibited the translocation of p65 from the cytosol to the nucleus. In addition, the three compounds inhibit cellular movement as shown by a fibronectin-based cellular adhesion assay, indicating that this compound exerts anti-invasive features. In an additional project, rosmarinic acid and salvianolic acid B were determined to be the main phenolic compounds from S. miltiorrhiza stem and leaf of callus culture. Here too, the cytotoxic activities could be determined. In summary, my findings suggest the possibility to isolation bioactive constituents with anti-cancer properties from in vitro callus cultures of stem and leaf of S. miltiorrhiza. These results may serve as starting point for drug development from this plant.
DDC:	500 Naturwissenschaften 500 Natural sciences and mathematics
Institution:	Johannes Gutenberg-Universität Mainz
Department:	FB 09 Chemie, Pharmazie u. Geowissensch.
Place:	Mainz
ROR:	https://ror.org/023b0x485
DOI:	http://doi.org/10.25358/openscience-2488
URN:	urn:nbn:de:hebis:77-diss-1000004089
Version:	Original work
Publication type:	Dissertation
License:	In Copyright
Information on rights of use:	https://rightsstatements.org/vocab/InC/1.0/
Extent:	136 S.
Appears in collections:	JGU-Publikationen