title: Ternatin, a cyclic peptide isolated from mushroom, and its derivative suppress hyperglycemia and hepatic fatty acid synthesis in spontaneously diabetic KK-A(y) mice.
abstract: (-)-Ternatin is a highly methylated cyclic heptapeptide isolated from mushroom Coriolus versicolor. Ternatin has an inhibitory effect on fat accumulation in 3T3-L1 adipocytes. [D-Leu(7)]ternatin, a ternatin derivative, also inhibited fat accumulation in 3T3-L1 cells, although the effectiveness of [D-Leu(7)]ternatin was lower than that of ternatin. In this study, we investigated the effects of ternatin and [D-Leu(7)]ternatin on obesity and type 2 diabetes in KK-A(y) mice, an animal model for spontaneously developed type 2 diabetes. We continuously administered ternatin (8.5 or 17 nmol/day) or [D-Leu(7)]ternatin (68 nmol/day) to mice via a subcutaneous osmotic pump. Unexpectedly, neither ternatin nor [D-Leu(7)]ternatin affected body weight or adipose tissue weight in KK-A(y) mice. In contrast, it was demonstrated that both ternatin and [D-Leu(7)]ternatin suppress the development of hyperglycemia. In liver, the SREBP-1c mRNA level tended to be lower or significantly decreased in mice treated with ternatin or [D-Leu(7)]ternatin, respectively. Moreover, we found that ternatin directly lowered the SREBP-1c mRNA level in Hepa1-6 hepatocyte cells. This study showed that ternatin and [D-Leu(7)]ternatin each had a preventive effect on hyperglycemia and a suppressive effect on fatty acid synthesis in KK-A(y) mice.
authors.affiliation: Department of Applied Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan.
authors.forename: Misato
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Haruna
authors.initials: H
authors.lastname: Kawashima
authors.forename: Kumiko
authors.initials: K
authors.lastname: Takemori
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ito
authors.forename: Atsushi
authors.initials: A
authors.lastname: Murai
authors.forename: Shun
authors.initials: S
authors.lastname: Masuda
authors.forename: Kaoru
authors.initials: K
authors.lastname: Yamada
authors.forename: Daisuke
authors.initials: D
authors.lastname: Uemura
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Horio
mesh_terms: D000818:Animals; D002460:Cell Line; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy* / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy* / Q000378:metabolism; D005227:Fatty Acids / Q000037:antagonists & inhibitors*; D006943:Hyperglycemia / Q000188:drug therapy*; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D010456:Peptides, Cyclic / Q000008:administration & dosage*
chemical_list: D005227:Fatty Acids; D010456:Peptides, Cyclic; C085773:ternatin heptapeptide