Tomato Glycoalkaloids:  Role in the Plant and in the Diet

Abstract

Tomatoes, a major food source for humans, accumulate a variety of secondary metabolites including phenolic compounds, phytoalexins, protease inhibitors, and glycoalkaloids. These metabolites protect against adverse effects of hosts of predators including fungi, bacteria, viruses, and insects. Because glycoalkaloids are reported to be involved in host-plant resistance, on the one hand, and to have a variety of pharmacological and nutritional properties in animals and humans, on the other, a need exists to develop a better understanding of the role of these compounds both in the plant and in the diet. To contribute to this effort, this integrated review presents data on the history, composition, and nutrition of tomatoes, with special focus on the assessment of the chemistry, analysis, composition, nutrition, microbiology, and pharmacology of the tomato glycoalkaloids comprising alpha-tomatine and dehydrotomatine; their content in different parts of the tomato plant, in processed tomato products, and in wild and transgenic tomatoes; their biosynthesis, inheritance, metabolism, and catabolism; plant-microbe relationships with fungi, bacteria, viruses, insects, and worms; interactions with ergosterol and cholesterol; disruption of cell membranes; tomatine-induced tomatinases, pantothenate synthetase, steroid hydroxylases, and cytokines; and inhibition of acetylcholinesterase. Also covered are tomato-human pathogen relationships and tomatine-induced lowering of plasma cholesterol and triglycerides and enhancement of the immune system. Further research needs in each of these areas are suggested. The overlapping aspects are discussed in terms of general concepts for a better understanding of the impact of tomato glycoalkaloids in the plant in general and in food in particular. Such an understanding can lead to the creation of improved tomatoes and to improved practices on the farm and in the consumption of tomatoes.

The anticancer activity of alpha-tomatine against mammary adenocarcinoma in mice

“…Whereas oral ΤΟΜ shows apparently lower toxicity than the potato glycoalkaloids α−chaconine and α−solanine 1,40 , presumably due to the poor absorption of ΤΟΜ complexes with cholesterol in the gut, the lethal i.p. doses of ΤΟΜ and potato glycoalkaloids are similar.…”

“…1). In plants, ΤΟΜ may provide defence against pathogenic fungi, bacteria, viruses and herbivores 1 . This effect corresponds with the content of the agent and changes throughout the lifespan of the tomato plant; e.g.…”

“…during tomato fruit maturation, the levels of ΤΟΜ decrease considerably, which, among other factors, brings about a reduction in the bitter flavour 2 . In mammals, a wide variety of health-promoting properties of ΤΟΜ have been reported, including the lowering of plasma concentrations of LDL and triacylglycerols 3 and cardiotonic 1 and antiviral activity 4 . ΤΟΜ may also contribute to the stimulation of antigen-specific humoral and cellular immune response, including the augmentation of anticancer defence 5 .…”

Evaluation of Solasonine Content and Expression Patterns of SGT1 Gene in Different Tissues of Two Iranian Eggplant (Solanum melongena L.) Genotypes

“…For instance, in potato (S. tuberosum L.), the major constituents of the GA family include trisaccharides α-solanine, α-chaconine, α-tomatine and dehydrotomatine, which are commonly found in tomato, while in eggplants, α-solasonine and α-solamargine are the most abundant spirosolane--type GAs (4,23,31). As mentioned before, SGAs can be found in all plant tissues, but they accumulate mainly in metabolically active tissues, including immature berries, flowers and young leaves or shoots.…”

O Tomate Como Alimento - Cadeia Produtiva E Resíduos De Agrotóxicos

“…Também podem reparar lesões causadas pelos radicais livres, removendo danos da molécula de DNA e reconstituindo membranas celulares danificadas. O tomate contém antioxidantes, tais como ácido ascórbico, â-caroteno, ácido clorogênico, rutina, plastoquinonas, tocoferol e xantofila, bem como elementos traços de cobre, ferro e cromo que podem atuar sinergicamente com o licopeno na prevenção de danos às células (FRIEDMAN, 2002).…”