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. (From The Merck Index, 11th ed) Tomatine is a mildly toxic glycoalkaloid or glycospirosolane (steroidal alkaloids whose structure contains a spirosolane skeleton) found in the stems and leaves of tomato plants as well as in the fruit of unripened (green) tomatoes (up to 500 mg/kg). Red, ripe tomatoes have somewhat reduced amounts of tomatine. A toxic dose of tomatine for an adult human would appear to require the consumption of at least 500 g of tomato leaves in one sitting (“Toxic Plants of North America” (Iowa State University Press, 2001)). Tomatine is known to have fungicidal and antimicrobial properties and is likely produced by tomato plants as a defense against bacteria, fungi, viruses, and insects (PMID: 19514731). Some microbes produce an enzyme called tomatinase which can degrade tomatine, rendering it ineffective as an antimicrobial (PMID: 18835993).Tomatine has historically been used as a reagent in analytical chemistry for precipitating cholesterol from solution (PMID: 4362143). When lab animals ingest tomatine, essentially all of it passes through the animal unabsorbed. Tomatine apparently binds to cholesterol in the digestive tract, and the largely insoluble combination is excreted — ridding the body of both the alkaloid and cholesterol. Experiments with hamsters have shown that both tomatine-rich green tomatoes and purified tomatine can substantially lower the levels of undesirable LDL cholesterol while maintaining normal levels of HDL (PMID: 10942315). Experiments with high-tomatine green tomato extracts were recently shown to strongly inhibit the growth of a number of human cancer cell lines including breast (MCF-7), colon (HT-29), gastric (AGS), and hepatoma (liver) (HepG2), as well as normal human liver cells (PMID: 19514731). Other studies have found that purified tomatine is an outstanding immunoadjuvant capable of stimulating potent antigen-specific humoral and cellular immune responses that contribute to protection against malaria, Francisella tularensis and regression of experimental tumors (PMID: 15193398).