title: Antiprotozoal Effects of the Tomato Tetrasaccharide Glycoalkaloid Tomatine and the Aglycone Tomatidine on Mucosal Trichomonads.
abstract: The present study investigated the inhibitory effects of the commercial tetrasaccharide tomato glycoalkaloid tomatine and the aglycone tomatidine on three mucosal pathogenic protozoa that are reported to infect humans, cattle, and cats, respectively: Trichomonas vaginalis strain G3, Tritrichomonas foetus strain D1, and Tritrichomonas foetus strain C1. A preliminary screen showed that tomatine at 100 μM concentration completely inhibited the growth of all three trichomonads. In contrast, the inhibition of all three pathogens by tomatidine was much lower, suggesting the involvement of the lycotetraose carbohydrate side chain in the mechanism of inhibition. Midpoints of concentration-response sigmoid plots of tomatine on the three strains correspond to IC50values, the concentration that inhibits 50% of growth of the pathogenic protozoa. The concentration data were used to calculate the IC50values for G3, D1, and C1 of 7.9, 1.9, and 2.2 μM, respectively. The results show an approximately 4-fold variation from the lowest to the highest value (lowest activity). Although the inhibition by tomatine was not as effective as that of the medicinal drug metronidazole, the relatively low IC50values for both T. vaginalis and T. foetus indicated tomatine as a possible natural alternative therapeutic for trichomoniasis in humans and food-producing (cattle and pigs) and domestic (cats) animals. Because tomatine has the potential to serve as a new antiprotozoan functional (medical) food, the distribution of this glycoalkaloid in tomatoes and suggestions for further research are discussed.
authors.affiliation: Department of Biological Sciences, University of the Pacific , Stockton, California 95211, United States.
authors.forename: Jenny
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Biological Sciences, University of the Pacific , Stockton, California 95211, United States.
authors.forename: Sierra
authors.initials: S
authors.lastname: Kanetake
authors.affiliation: Department of Biological Sciences, University of the Pacific , Stockton, California 95211, United States.
authors.forename: Yun-Hsuan
authors.initials: YH
authors.lastname: Wu
authors.affiliation: Foodborne Toxin Detection and Prevention, Agricultural Research Service, United States Department of Agriculture , Albany, California 94556, United States.
authors.forename: Christina
authors.initials: C
authors.lastname: Tam
authors.affiliation: Foodborne Toxin Detection and Prevention, Agricultural Research Service, United States Department of Agriculture , Albany, California 94556, United States.
authors.forename: Luisa W
authors.initials: LW
authors.lastname: Cheng
authors.affiliation: Department of Biological Sciences, University of the Pacific , Stockton, California 95211, United States.
authors.forename: Kirkwood M
authors.initials: KM
authors.lastname: Land
authors.affiliation: Healthy Processed Foods Research, Agricultural Research Service, United States Department of Agriculture , Albany, California 94556, United States.
authors.forename: Mendel
authors.initials: M
authors.lastname: Friedman
mesh_terms: D000818:Animals; D000981:Antiprotozoal Agents / Q000737:chemistry / Q000494:pharmacology*; D018551:Solanum lycopersicum / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D014053:Tomatine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology*; D016834:Trichomonadida / Q000737:chemistry / Q000187:drug effects*
chemical_list: D000981:Antiprotozoal Agents; D010936:Plant Extracts; C003677:tomatidine; D014053:Tomatine
keywords: Trichomonas vaginalis; Tritrichomonas foetus; growth inhibition; infections; tomatidine; tomatine; tomatoes; trichomoniasis prevention