Related Experiment Video
Updated: May 16, 2026
Biosynthesis of a Flavonol from a Flavanone by Establishing a One-pot Bienzymatic Cascade
Published on: August 14, 2019
Profiling flavonoid cytotoxicity in human breast cancer cell lines: determination of structure-function relationships
Sina Yadegarynia1, Anh Pham, Alex Ng
1Department of Biological Sciences, San Jose State University, San Jose, CA 95192, USA.
Abstract:
Flavonoids have been shown to be cytotoxic to cancer cells. However, the mechanism of cytotoxicity has not been clearly defined. It has previously been reported that HER2/ERBB2, the estrogen receptor, progesterone receptor, and p53 were required for flavonoid induced cytotoxicity in breast cancer cell lines. We have used a panel of breast cancer cell lines, known to contain as well as be deficient in these signaling pathways, to screen fourteen different flavonoids. Comparing the cytotoxicity for all flavonoids allows us to determine if a structure-functional relationship exists between cytotoxicity and flavonoid, and if a particular signaling pathway is required for cytotoxicity. We show that several flavonoids are cytotoxic to all cell lines including primary mammary epithelial cells tested. The cytotoxic flavonoids are also able to inhibit Mitochondrial Outer Membrane Permeability while at the same time stimulate ATP levels whereas the non-cytotoxic flavonoids are not able to do this. We also show that both cytotoxic and non-cytotoxic flavonoids can transverse the cell membrane to enter MDA-MB-231 cells at different levels. Finally, all flavonoids regardless of their cytotoxicity were able to induce some form of cell cycle arrest. We conclude that for flavonoids to be strongly cytotoxic, they must possess the 2,3-double bond in the C-ring and we believe the cytotoxicity occurs through mitochondrial poisoning in both cancer and normal cells.
Insights
Flavonoids show cytotoxicity against cancer cells by poisoning mitochondria, a process requiring a specific C-ring structure. This mechanism affects both cancer and normal cells, impacting mitochondrial outer membrane permeability and ATP levels.
Area of Science:
- Biochemistry
- Cell Biology
- Pharmacology
Background:
- Flavonoids exhibit cytotoxicity towards cancer cells, but the precise mechanisms remain unclear.
- Previous research suggested the involvement of HER2/ERBB2, estrogen receptor, progesterone receptor, and p53 in flavonoid-induced cytotoxicity in breast cancer.
Purpose of the Study:
- To investigate the structure-function relationship of flavonoids regarding their cytotoxicity.
- To determine if specific signaling pathways are essential for flavonoid-induced cytotoxicity.
- To elucidate the mechanism underlying flavonoid cytotoxicity in breast cancer cells.
Main Methods:
- Screening of fourteen different flavonoids using a panel of breast cancer cell lines with varying signaling pathway statuses.
- Assessment of flavonoid cytotoxicity, mitochondrial outer membrane permeability, ATP levels, cellular uptake, and cell cycle arrest.
- Comparison of cytotoxic and non-cytotoxic flavonoids to identify structural requirements and affected pathways.
Main Results:
- Several flavonoids demonstrated cytotoxicity across all tested cell lines, including normal mammary epithelial cells.
- Cytotoxic flavonoids inhibited mitochondrial outer membrane permeability and stimulated ATP levels, unlike non-cytotoxic ones.
- All tested flavonoids, regardless of cytotoxicity, induced cell cycle arrest; cytotoxic flavonoids required a 2,3-double bond in the C-ring.
Conclusions:
- Flavonoid cytotoxicity is strongly correlated with the presence of a 2,3-double bond in the C-ring.
- The primary mechanism of flavonoid cytotoxicity appears to be mitochondrial poisoning, affecting both cancerous and normal cells.
- Flavonoid uptake into cells varies, but cell cycle arrest is a common outcome across all tested compounds.
Related Concept Videos
01:11Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
02:59Cancer Prevention
Some...