Tomatine-containing green tomato extracts inhibit growth of human breast, colon, liver, and stomach cancer cells.
Level 5 - mechanism / opinion, no new human data
In vitro laboratory bench study on cultured cell lines without human or animal subjects.
PubMed 19514731 · doi:10.1021/jf900364j
What was done
Researchers evaluated the cytotoxic effects of six green tomato extracts (high tomatine) and three red tomato extracts (low tomatine) on human cancer cell lines—breast (MCF-7), colon (HT-29), gastric (AGS), and liver hepatoma (HepG2)—as well as normal human liver cells (Chang) using an MTT cell viability assay. They also tested purified glycoalkaloids (alpha-tomatine, dehydrotomatine) and their aglycones (tomatidine, tomatidenol) isolated and characterized via HPLC, GC, and GC-MS.
What was found
The abstract provides no exact numerical values (such as IC50 concentrations or percentage inhibition rates). It reports that high-tomatine green tomato extracts and pure alpha-tomatine strongly inhibited all four cancer cell lines as well as the normal Chang liver cells. Low-tomatine red tomato extracts, dehydrotomatine, tomatidenol, and tomatidine showed little to no inhibitory activity against the tested cell lines.
Why it matters
This study demonstrates that the glycoalkaloid alpha-tomatine in green tomatoes possesses in vitro cytotoxic activity against multiple human cancer cell types, suggesting biological properties distinct from the carotenoids found in ripe red tomatoes.
Limits
The study is entirely in vitro and does not assess in vivo safety, bioavailability, metabolism, or efficacy in animals or humans. Furthermore, alpha-tomatine and green tomato extracts also inhibited normal human liver cells, indicating non-selective cytotoxicity that requires further toxicity assessment.
Cited by
- supports Tomatidine is highly concentrated in green tomatoes, and its concentration declines dramatically as the tomato turns red.