title: Enhancement of Combined Umami and Salty Taste by Glutathione in the Human Tongue and Brain.
abstract: Glutathione, a natural substance, acts on calcium receptors on the tongue and is known to enhance basic taste sensations. However, the effects of glutathione on brain activity associated with taste sensation on the tongue have not been determined under standardized taste delivery conditions. In this study, we investigated the sensory effect of glutathione on taste with no effect of the smell when glutathione added to a combined umami and salty taste stimulus. Twenty-six volunteers (12 women and 14 men; age 19-27 years) performed a sensory evaluation of taste of a solution of monosodium L-glutamate and sodium chloride, with and without glutathione. The addition of glutathione changed taste qualities and significantly increased taste intensity ratings under standardized taste delivery conditions (P < 0.001). Functional magnetic resonance imaging showed that glutathione itself elicited significant activation in the left ventral insula. These results are the first to demonstrate the enhancing effect of glutathione as reflected by brain data while tasting an umami and salty mixture.
authors.affiliation: Oral Diagnosis & Polyclinics, Faculty of Dentistry, The University of Hong Kong, 34 Hospital Road, Hong Kong, Department of Oral and Maxillofacial Radiology, Tokyo Dental College, 2-9-18, Misakicho, Chiyoda-ku, Tokyo 101-0061, Japan, tkgoto@tdc.ac.jp.
authors.forename: Tazuko K
authors.initials: TK
authors.lastname: Goto
authors.affiliation: Oral Diagnosis & Polyclinics, Faculty of Dentistry, The University of Hong Kong, 34 Hospital Road, Hong Kong.
authors.forename: Andy Wai Kan
authors.initials: AW
authors.lastname: Yeung
authors.affiliation: Graduate School of Environmental Studies, Department of Social and Human Environment, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.
authors.forename: Hiroki C
authors.initials: HC
authors.lastname: Tanabe
authors.affiliation: Mitsubishi Shoji Foodtech Co., Ltd., 1-1-3, Yurakucho, Chiyoda-ku, Tokyo 100-0006, Japan, Section of Oral Neuroscience, Graduate School of Dental Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Ito
authors.affiliation: Oral Biosciences, Faculty of Dentistry, The University of Hong Kong, 34 Hospital Road, Hong Kong.
authors.forename: Han-Sung
authors.initials: HS
authors.lastname: Jung
authors.affiliation: Section of Oral Neuroscience, Graduate School of Dental Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan, Division of Sensory Physiology, Research and Development Center for Taste and Odor Sensing, Kyushu University, Collaboration station II, 307/308, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan and Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA19104-3308, USA.
authors.forename: Yuzo
authors.initials: Y
authors.lastname: Ninomiya
mesh_terms: D000328:Adult; D001921:Brain / Q000187:drug effects; D005260:Female; D005978:Glutathione / Q000494:pharmacology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D013649:Taste / Q000502:physiology; D055697:Taste Perception / Q000187:drug effects*; D014059:Tongue / Q000187:drug effects*
chemical_list: D005978:Glutathione
keywords: glutathione; human taste; insular cortex; monosodium L-glutamate; neuroimaging; umami and salty