Tomatine (C50H83NO21) is an alkaloid that occurs in the extract of leaves of wild tomato
plants. It has been found to inhibit the growth of various fungi and bacteria.
It is used as a precipitating agent for steroids.
The a-tomatine is thought to protect wild potato and tomato against attacks
by phytopathogenic (harmful to plants) fungi. In tomato cultivars used for food,
tomatine decreases during ripening from 0.08% in mature green fruit to 0.00% in
ripe fruit. Tomatine, in contrast to some other alkaloids in Solanaceae family, is not toxic.2
Recently, green and red tomato extracts were investigated for their ability
to induce cell death in human cancer and normal cells. Compared to untreated
cells, the high-tomatine green tomato extracts strongly inhibited the following
human cancer cells: breast, colon, gastric, and liver, as well as normal human
liver cells. These findings extend related observations on the anticarcinogenic
potential of glyco alkaloids and suggest that consumers may benefit by eating not only high-lycopene red tomatoes but also green tomatoes containing glyco alkaloids.3