• Journal of Dairy Science and Biotechnology
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• v.39 no.2
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• pp.78-85
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• 2021

Previously, we showed that oral administration of probiotics, Lactobacillus acidophilus NS1 (LNS1), improved insulin sensitivity in high-fat-diet-fed mice (HFD mice). Furthermore, LNS1-conditioned media (LNS1-CM) reduced HNF4α transcription activity and the expression of phosphoenol pyruvate carboxykinase (PEPCK), a key enzyme in gluconeogenesis in HepG2 cells. In this study, we demonstrated that LNS1 administration increased the expression of glycosyltransferase 2 (GYS2) and glucose transporter 2 (GLUT2), while reduced the expression of glucose-6-phosphatase (G6PC) expression in liver of HFD mice. Furthermore, LNS1 suppressed hepatic expression of glucokinase regulatory unit (GCKR) in HFD mice without changing the mRNA levels of glucokinase (GCK), suggesting that LNS1 may inhibit nuclear GCK activity. Consistently, addition of LNS1-CM to HepG2 cells increased the mRNA levels of GYS2 and GLUT2 with reduced mRNA levels of G6PC and GCKR. Moreover, hepatic glycogen contents were increased in HFD mice upon administration of LNS1. Together, these results suggest that LNS1 facilitates glycogen accumulation in liver by regulating the expression of genes involved in glycogen metabolism, contributing to improved insulin sensitivity in the HFD mice.

• Journal of Nutrition and Health
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• v.43 no.4
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• pp.333-341
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• 2010

The aim of this study was to investigate the hypolgycemic activity of water extract of fermented yacon (Smallanthus sonchifolius) leaves tea (Yacon LWE) in high-fat diet (HFD)/streptozotocin (STZ)-induced diabetic mice. Male ICR mice were fed with a HFD (37% calories from fat) for 4 weeks prior to intraperitoneal injection with STZ (100 mg/kg body weight). Diabetic mice were supplemented with two doses of Yacon LWE (0.16% and 0.8%, wt/wt) for 6 weeks. The supplementation of high-dose Yacon LWE significantly lowered blood glucose levels and plasma ALT and AST activities compared with the control group. High-dose Yacon LWE also improved the insulin tolerance without any changes in plasma and pancreatic insulin concentrations in HFD/STZ-induced diabetic mice. Yacon LWE supplementation increased the insulin staining of pancreatic $\beta$-cells in a dose-dependent manner. Both 0.16% and 0.8% of Yacon LWE significantly elevated plasma leptin concentration, hepatic glucokinase activity and glucokinase/glucose-6-phosphatase ratio compared with the control group. However, glycosylated hemoglobin concentration was not different among the groups. These results suggest that high-dose Yacon LWE lowers the blood glucose level partly by enhancing insulin sensitivity and hepatic glucose metabolism in type 2 diabetic mice.