Pterocarpan-enriched soy leaf extract ameliorates insulin sensitivity and pancreatic β-cell proliferation in type 2 diabetic mice.
In Korea, soy (Glycine max (L.) Merr.) leaves are eaten as a seasonal vegetable or pickled in soy sauce. Ethyl acetate extracts of soy leaves (EASL) are enriched in pterocarpans and have potent α-glucosidase inhibitory activity. This study investigated the molecular mechanisms underlying the anti-diabetic effect of EASL in C57BL/6J mice with high-fat diet (HFD)-induced type 2 diabetes. Mice were randomly divided into normal diet (ND), HFD (60 kcal% fat diet), EASL (HFD with 0.56% (wt/wt) EASL), and Pinitol (HFD with 0.15% (wt/wt) pinitol) groups. Weight gain and abdominal fat accumulation were significantly suppressed by EASL. Levels of plasma glucose, HbA1c, and insulin in the EASL group were significantly lower than those of the HFD group, and the pancreatic islet of the EASL group had greater size than those of the HFD group. EASL group up-regulated neurogenin 3 (Ngn3), paired box 4 (Pax4), and v-maf musculoaponeurotic fibrosarcoma oncogene homolog A (MafA), which are markers of pancreatic cell development, as well as insulin receptor substrate 1 (IRS1), IRS2, and glucose transporter 4 (GLUT4), which are related to insulin sensitivity. Furthermore, EASL suppressed genes involved in hepatic gluconeogenesis and steatosis. These results suggest that EASL improves plasma glucose and insulin levels in mice with HDF-induced type 2 diabetes by regulating β-cell proliferation and insulin sensitivity.
Industrial Bio-materials Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, Korea. kuhalice@kribb.re.kr.
Un-Hee
UH
Kim
Industrial Bio-materials Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, Korea. hyun11-10@hanmail.net.
Jeong-Hyun
JH
Yoon
Industrial Bio-materials Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, Korea. Leehua@kribb.re.kr.
Hua
H
Li
Industrial Bio-materials Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, Korea. bsloauclk@naver.com.
Ji-Hyun
JH
Kang
Industrial Bio-materials Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, Korea. gustjs@kribb.re.kr.
Hyeon-Seon
HS
Ji
Division of Applied Life Science, Gyeongsang National University, Jinju 660-701, Korea. khpark@gnu.ac.kr.
Ki Hun
KH
Park
Insect Biotech Co. Ltd., Daejeon 305-811, Korea. dhshin@insectbiotech.co.kr.
Dong-Ha
DH
Shin
Industrial Bio-materials Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, Korea. dhshin@insectbiotech.co.kr.
Ho-Yong
HY
Park
Industrial Bio-materials Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, Korea. tsjeong@kribb.re.kr.
Tae-Sook
TS
Jeong
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects*; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000188:drug therapy* / Q000473:pathology; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy* / Q000473:pathology; D007004:Hypoglycemic Agents / Q000737:chemistry / Q000494:pharmacology*; D007333:Insulin Resistance; D050417:Insulin-Secreting Cells / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D018515:Plant Leaves / Q000737:chemistry*; D036343:Pterocarpans / Q000737:chemistry / Q000494:pharmacology*; D013025:Glycine max / Q000737:chemistry*
D001786:Blood Glucose; D007004:Hypoglycemic Agents; D036343:Pterocarpans