Anticancer Mechanisms

EGCG is the main catechin in green tea, and its anticancer relevance comes from unusually broad pathway activity.

Primary mechanisms

1. EGFR and growth-factor signalling inhibition

• Binds to EGFR and reduces autophosphorylation

• Suppresses downstream MAPK/ERK and PI3K/Akt signalling

• Reduces mTOR-pathway activity in several tumour models

2. Apoptosis induction

• Activates caspase-dependent cell death pathways

• Increases Bax/Bcl-2 ratio

• Promotes cytochrome c release and mitochondrial apoptotic signalling

3. Cell-cycle arrest

• Induces G1 arrest in many models

• Upregulates p21 and p27

• Downregulates cyclins and cyclin-dependent kinases tied to proliferation

4. Anti-angiogenic effects

• Inhibits VEGF

• Suppresses HIF-1α-linked angiogenic signalling

• Reduces MMP-2 and MMP-9 in invasive models

5. Metastasis suppression

• Inhibits EMT-related signalling

• Reduces invasion and migration markers

• Suppresses uPA and other metastasis-promoting pathways

6. Telomerase inhibition

• Inhibits hTERT-related activity in cancer cells

• Supports long-term growth-control mechanisms in some models

Secondary mechanisms

• NF-κB inhibition

• STAT3 suppression

• autophagy modulation

• DNA methyltransferase-related epigenetic effects

• cancer stem-cell targeting

• proteasome-related effects at higher concentrations

Practical interpretation

EGCG is best understood as a pleiotropic adjunct rather than a single-target intervention. This is one reason green tea catechin research has remained so active across multiple cancer types.

Key References

Epigallocatechin-3-Gallate Therapeutic Potential in Cancer: Mechanism of Action and Clinical Implications
https://pmc.ncbi.nlm.nih.gov/articles/PMC10343677/

Effects of Epigallocatechin Gallate Against Lung Cancer
https://pmc.ncbi.nlm.nih.gov/articles/PMC12899071/

Novel anti-cancer stem cell compounds
https://pmc.ncbi.nlm.nih.gov/articles/PMC11360402/

Targeting Notch signaling pathways with natural bioactive compounds in cancer
https://www.frontiersin.org/articles/10.3389/fphar.2024.1412669/full