Soy Leaf Extract Containing Kaempferol Glycosides and Pheophorbides Improves Glucose Homeostasis by Enhancing Pancreatic beta-Cell Function and Suppressing Hepatic Lipid Accumulation in db/db Mice

作者：Li Hua; Ji Hyeon Seon; Kang Ji Hyun; Shin Dong Ha; Park Ho Yong; Choi Myung Sook; Lee Chul Ho; Lee In Kyung; Yun Bong Sik; Jeong Tae Sook^*

来源：Journal of Agricultural and Food Chemistry, 2015, 63(32): 7198-7210.

DOI：10.1021/acs.jafc.5b01639

• soy (Glycine max) leaf
• kaempferol
• pheophorbide a
• glucose homeostasis
• IRS
• SREBP-1

This study investigated the molecular mechanisms underlying the antidiabetic effect of an ethanol extract of soy leaves (ESL) in db/db mice. Control groups (db/+ and db/db) were fed a normal diet (ND), whereas the db/db-ESL group was fed ND with 1% ESL for 8 weeks. Dietary ESL improved glucose tolerance and lowered plasma glucose, glycated hemoglobin, HOMA-IR, and triglyceride levels. The pancreatic insulin content of the db/db-ESL group was significantly greater than that of the db/db group. ESL supplementation altered pancreatic IRS1, IRS2, Pdx1, Ngn3, Pax4, Ins1, Ins2, and FoxO1 expression. Furthermore, ESL suppressed lipid accumulation and increased glucokinase activity in the liver. ESL primarily contained kaempferol glycosides and pheophorbides. Kaempferol, an aglycone of kaempferol glycosides, improved beta-cell proliferation through IRS2-related FoxO1 signaling, whereas pheophorbide a, a product of chlorophyll breakdown, improved insulin secretion and beta-cell proliferation through IRS1-related signaling with protein kinase A in MIN6 cells. ESL effectively regulates glucose homeostasis by enhancing IRS-mediated beta-cell insulin signaling and suppressing SREBP-1-mediated hepatic lipid accumulation in db/db mice.

• 出版日期2015-8-19