Cancer Chemoprevention
Phytochemicals
1. Detoxification
Nrf2
Antioxidant enzymes
Phase 2 enzymes
Promotes transcription of antioxidant genes and Enhances biotransformation of carcinogens
2. Down-regulation of COX-2 & PGE2 pathway
Inflammatory mediators e.g. COX-2
Prevent epithelial cell proliferation angiogenesis, decrease mutagens and anti-apoptotic proteins etc.
3. Apoptosis induction
Anti-apoptotic proteins e.g. Bcl2
Pro-apoptotic proteins e.g. Bax
Caspases activation to promote apoptosis by death receptor or
mitochondrial pathway.
4. Cell cycle arrest
G1 & G2/M arrest
CDK inhibitors
Cyclins
Regulation of cell cycle process and Prevent cell division.
5.Inhibition of Angiogenesis
Pro-angiogenic factors e.g. VEGF, Angiogenin
Anti-angiogenic factors e.g. Angiostatin, endostatin
Prevent formation of new blood vessels
6. Upregulation of GJIC
Connexons
Increase in number of channels to allow transmission of growth
inhibition factors.
7. Modulation of signal transduction pathways
Notorious transcription factors e.g. Nf-kB, MAPK, C-Myc
Lead to tumour supression, apoptosis induction, angiogenesis inhibition,
decrease in inflammatory bodies etc.