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3-O-[(E)-4-(4-cyanophenyl)-2-oxobut-3-en-1-yl] kaempferol is a novel lead compound to discover anti-diabetic and anti-obesity drugs. The present study reported the scaffold hopping of the lead compound to obtain a new isoxazole derivative, C45, which has improved glucose consumption at the nanomolar level (EC 50  = 0.8 nM) in insulin resistant (IR) HepG2 cells. Western blotting showed that C45 markedly enhanced the phosphorylation of AMPK (AMP-activated protein kinase) and reduced the levels of the gluconeogenesis key enzymes PEPCK (phosphoenolpyruvate carboxykinase) and G6Pase (glucose 6-phosphatase) in HepG2 cells. The potential molecular mechanism of C45 may be activation of the AMPK/PEPCK/G6Pase pathways. We concluded that C45 might be a valuable candidate to discover anti-diabetic drugs., Competing Interests: Declaration of Competing Interest There are no conflicts to declare., (Copyright © 2020 Elsevier B.V. All rights reserved.)

In high fat diet-induced obese mice, the flavonoid derivative of tiliroside, Fla-CN, has antihyperglycemic effects, can improve insulin sensitivity, ameliorate metabolic lipid disorders, and benefits certain disorders characterized by insulin resistance. Fla-CN is a novel lead compound to discovery anti-diabetic and anti-obesity drugs. The present study reported the optimization of Fla-CN to obtain a new derivative, 10b, which has improved glucose consumption at the nanomolar level (EC 50  = 0.3 nM) in insulin resistant (IR) HepG2 cells. 10b also increased the glycogen content and glucose uptake, and concurrently inhibited gluconeogenesis in HepG2 cells. Western blotting showed that 10b markedly enhanced the phosphorylation of AMPK (AMP-activated protein kinase) and AS160 (protein kinase B substrate of 160 kDa) and reduced the levels of the gluconeogenesis key enzymes PEPCK (phosphoenolpyruvate carboxykinase) and G6P (glucose 6-phosphatase) in HepG2 cells. The potential molecular mechanism of 10b may be activation of the AMPK/AS160 and AMPK/PEPCK/G6P pathways. We concluded that 10b might be a valuable candidate to discover anti-diabetic drugs., Competing Interests: Declaration of Competing Interest None., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Introduction: The Chinese herb Potentilla chinensis can reduce blood glucose level of diabetic mice. Tiliroside is the main effective component, but the detailed mechanism is not clear. Skeletal muscles play an important role in whole body glucose homeostasis. Insulin and exercise/contraction stimulate glucose uptake by muscle cells via redistribution of glucose transporter GLUT4 to the cell surface., Materials and Methods: We explored the effects of tiliroside derivatives on cell surface GLUT4 level (GLUT4 translocation) and the underlying mechanism in L6-GLUT4 myc muscle cells., Results: We showed that tiliroside derivatives D1-22 stimulated GLUT4 myc translocation in L6-GLUT4 myc skeletal muscle cells. Derivatives D1, D8 and D18 regulated GLUT4 myc translocation in a time- and dose-dependent manner. Their effects on GLUT4 were additive with that of acute insulin stimulation. Moreover, they increased phosphorylated adenosine monophosphate-activated protein kinase (AMPK), but not protein kinase B (PKB, also called Akt). Their effects on GLUT4 were inhibited by Compound C. In addition, derivative D8 significantly stimulated AMPK and Akt substrate of 160 kDa (AS160) phosphorylation and GLUT4 myc translocation in L6-GLUT4 myc cells, but not in L6-AS160 4A-GLUT4 myc cells., Conclusion: Tiliroside derivatives D1, D8 and D18 stimulated GLUT4 myc translocation by a mechanism different to that of insulin in skeletal muscle cells. The effect of derivative D8 on GLUT4 myc translocation is mediated by AMPK/AS160 signaling pathway., Competing Interests: Disclosure The authors report no conflicts of interest in this work.

In our previous study, a derivative of tiliroside, 3-O-[(E)-4-(4-ethoxyphenyl)-2-oxobut-3-en-1-yl]kaempferol (Fla-OEt) significantly enhanced glucose consumption in insulin resistant HepG2 cells. This article deals with the antihyperglycemic and antihyperlipidemic effects of Fla-OEt in diet-induced obesity (DIO) mice. Daily administration of Fla-OEt significantly decreased oral glucose tolerance test, intraperitoneal insulin tolerance test and serum lipids. Hyperinsulinemic-euglycemic clamp and the ratio of high-density-lipoprotein/low-density-lipoprotein with Fla-OEt treatment were increased comparing with high-fat diet (HFD) group, so lipid metabolism was improved. Histopathology examination showed that the Fla-OEt restored the damage of adipose tissues and liver in DIO mice. Moreover, compared with HFD group, Fla-OEt treatment significantly increased the phosphorylation of AMPK and ACC in adiposity tissues, liver, and muscles. The mechanism of its action might be the activation of AMPK pathway. It appears that Fla-OEt is worth further study for development as a lead compound for a potential antidiabetic agent.

In a study to evaluate the structural elements essential for the antidiabetic activity of flavonoids, we synthesized two series of flavonoids, 5,7-dihydroxyflavanones and 5,7-dihydroxyflavones. In a screening for potential antidiabetic activity, most of the flavonoids showed a remarkable in vitro activity, and compounds 1f, 2d, and 3c were significantly more effective than the positive control, metformin. The biological activity was mainly affected by structural modification at the ring B moiety of the flavonoid skeleton. The results suggest that 5,7-dihydroxyflavonoids can be considered as promising candidates in the development of new antidiabetic lead compounds., (Copyright © 2012 Verlag Helvetica Chimica Acta AG, Zürich.)

A series of new tiliroside derivatives were synthesized and characterized by analytical (1)H NMR, (13)C NMR and mass spectrometry. All of the compounds were evaluated for anti-diabetic properties in vitro using HepG2 cells. Compounds 3c, 3d, and 3i-l caused significant enhancements in glucose consumption by insulin-resistant HepG2 cells compared with control cells and cells that were exposed to metformin (an anti-diabetic drug). Moreover, compound 3l significantly activated adenosine 5'-monophosphate-activated protein kinase activity and reduced acetyl-CoA carboxylase activity. Thus, the tiliroside derivative 3l offers potential to be developed as a new approach for treating type II diabetes., (Copyright © 2011 Elsevier Masson SAS. All rights reserved.)

Aim of the Study: The present study was carried out to isolate and identify trans-tiliroside as principal compound with anti-hyperglycemic, anti-hyperlipidemic and antioxidant effects from Potentilla chinesis., Materials and Methods: A bioactive compound, trans-tiliroside was isolated from the ethanol extract of Potentilla chinesis and its administration dose was optimized and patented. The normal, alloxan-induced diabetic mice and streptozotocin-induced diabetic rats were used to evaluate the anti-hyperglycemic, anti-hyperlipidemic and antioxidant effects of trans-tiliroside from Potentilla chinesis. Biochemical parameters were assayed in blood samples of different groups of alloxan-induced diabetic mice and streptozotocin-induced diabetic rats., Results: The level of fasting serum glucose levels, triglycerides (TG) and total cholesterol (TC) in alloxan-induced diabetic mice were significantly decrease after daily oral administration of trans-tiliroside in normal and diabetic mice at doses of 0.4, 0.8 and 1.6 mg/kg/day, for 15 days. Blood glucose level was significant decrease in STZ induced diabetic rats by trans-tiliroside (1.2 and 0.3mg/kg body weight for 10 weeks). The content of TC, low density lipoprotein (LDL-C) and TG levels were decreased and high density lipoprotein (HDL-C) content was increased, so lipid metabolism was improved. Moreover, trans-tiliroside revealed antioxidant activity as shown by increased activities of superoxide dismutase (SOD), decreased level of malondialdehyde (MDA) in diabetic rats. Histological morphology examination showed that the trans-tiliroside restored the damage of pancreas tissues in rats with diabetes mellitus., Conclusion: Trans-tiliroside, a constituent from Potentilla chinesis, revealed significant anti-hyperglycemic, anti-hyperlipidemic and antioxidant activities., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Tiliroside isolated from Chinese herb Potentilla chinensis showed therapeutic activities in diabetes. We synthesized 7 tiliroside-derivatives and examined their effects on surface GLUT4myc levels in muscle cells. Derivatives 2a and 3 increased surface GLUT4myc levels, and derivative 3 has the greatest potential. AMPK may be involved in tiliroside-derivatives-regulated GLUT4myc traffic., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Abstract: A chemical investigation of Tongoloa silaifolia led to the isolation of 12 compounds including seven coumarins, isoimperatorin (2), 7,8-dihydroxycoumarin (4), bergapten (6), phellopterin (7), isopimpinellin (8), 7-O-β-d-glucoside-8-hydroxycoumarin (11), 8-O-β-d-glucoside-7-hydroxycoumarin, (12), three flavonoids, luteolin (3), apigenin (5), luteolin-7-O-β-glucopyranoside (9), and two sterols, sitosterol (1), daucosterol (10). All of the compounds were found for the first time in Tongoloa species, while compounds 4 and 11 were new for the family Umbelliferae. The results support that coumarins are among the most characteristic and distinguishable chemical markers of the genus Tongoloa as well as of the Umbelliferae. [Copyright &y& Elsevier]

Fla-CN (3-O-[(E)-4-(4-cyanophenyl)-2-oxobut-3-en-1-yl] kaempferol) is a semi-synthesized flavonoid derivative of tiliroside which exhibited anti-diabetic effect in vivo . Our previous study revealed the role of Fla-CN in anti-obesity and anti-diabetes in vivo , but the underlying mechanism remained to be addressed. The present study aimed to investigate the mechanism of anti-adipogenesis in vitro . Fla-CN markedly inhibited intracellular lipid accumulation in a dose-dependent manner, and the inhibitory effect was mainly limited to the early stage of adipocyte differentiation in vitro . Further investigations revealed that Fla-CN up-regulated the expression level of miR-27a/b and suppressed its target genes expression including peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT/enhancer binding protein α (C/EBPα). Furthermore, the phosphorylation of AMP-activated protein kinase (AMPK) was also enhanced by Fla-CN in pre-adipocyte differentiation. These effects were abolished when cells were treated with miR-27a/b inhibitor and AMPK inhibitor Compound C. Additionally, Fla-CN reduced the expressions of adipocyte-specific genes such as sterol regulatory element-binding transcription factor 1c (SREBP-1c), fatty acid synthase (FAS) and adipocyte fatty acid binding protein (aP2). In conclusion, these results suggested a mechanism of Fla-CN for adipocyte differentiation inhibition of 3T3-L1 cells through miR-27a/b induction and AMPK activation. [ABSTRACT FROM AUTHOR]