title: Rikkunshito, a Japanese kampo medicine, ameliorates decreased feeding behavior via ghrelin and serotonin 2B receptor signaling in a novelty stress murine model.
abstract: We investigated the effects of rikkunshito (RKT), a ghrelin signal enhancer, on the decrease in food intake after exposure to novelty stress in mice. RKT administration (500 mg/kg, per os) improved the decrease in 6 h cumulative food intake. In control mice, the plasma acylated ghrelin levels significantly increased by 24 h fasting. In contrast, the acylated ghrelin levels did not increase by fasting in mice exposed to the novelty stress. RKT administration to the novelty stress mice showed a significant increase in the acylated ghrelin levels compared with that in the distilled-water-treated control mice. Food intake after administering serotonin 2B (5-HT(2B)) receptor antagonists was evaluated to clarify the role of 5-HT(2B) receptor activation in the decrease in feeding behavior after novelty stress. SB215505 and SB204741, 5-HT(2B) receptor antagonists, significantly improved the decrease in food intake after exposure to novelty stress. A component of RKT, isoliquiritigenin, prevented the decrease in 6 h cumulative food intake. Isoliquiritigenin showed 5-HT(2B) receptor antagonistic activity in vitro. In conclusion, the results suggested that RKT improves the decrease in food intake after novelty stress probably via 5-HT(2B) receptor antagonism of isoliquiritigenin contained in RKT.
authors.affiliation: Tsumura Research Laboratories, Tsumura & Co., Ibaraki 300-1192, Japan.
authors.forename: Chihiro
authors.initials: C
authors.lastname: Yamada
authors.forename: Yayoi
authors.initials: Y
authors.lastname: Saegusa
authors.forename: Koji
authors.initials: K
authors.lastname: Nakagawa
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Ohnishi
authors.forename: Shuichi
authors.initials: S
authors.lastname: Muto
authors.forename: Miwa
authors.initials: M
authors.lastname: Nahata
authors.forename: Chiharu
authors.initials: C
authors.lastname: Sadakane
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Hattori
authors.forename: Naoya
authors.initials: N
authors.lastname: Sakamoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takeda
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D047188:Chalcones / Q000494:pharmacology; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D004435:Eating / Q000187:drug effects*; D004791:Enzyme Inhibitors / Q000493:pharmacokinetics; D005247:Feeding Behavior / Q000187:drug effects*; D054439:Ghrelin / Q000097:blood*; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D008297:Male; D020835:Medicine, Kampo; D051379:Mice; D011804:Quinolines / Q000494:pharmacology; D044403:Receptor, Serotonin, 5-HT2B / Q000378:metabolism*; D058830:Serotonin 5-HT2 Receptor Antagonists / Q000494:pharmacology*; D013315:Stress, Psychological / Q000097:blood / Q000188:drug therapy; D014508:Urea / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D047188:Chalcones; D004365:Drugs, Chinese Herbal; D004791:Enzyme Inhibitors; D054439:Ghrelin; D007211:Indoles; C092756:N-(1-methyl-5-indolyl)-N'-(3-methyl-5-isothiazolyl)urea; D011804:Quinolines; D044403:Receptor, Serotonin, 5-HT2B; C118948:SB 215505; D058830:Serotonin 5-HT2 Receptor Antagonists; C084136:liu-jun-zi-tang; D014508:Urea; C040920:isoliquiritigenin