The Flower Tea Coreopsis tinctoria Increases Insulin Sensitivity and Regulates Hepatic Metabolism in Rats Fed a High-Fat Diet

Abstract

An infusion of Coreopsis tinctoria (CT) flowering tops is traditionally used in Portugal to control hyperglycemia; however, the effects of CT protection against high-fat diet (HFD)-induced hepatic insulin resistance have not been systematically studied and the precise mechanism of action is not clear. The metabolomic profiles of insulin-resistant rats fed a HFD and a CT-supplemented diet (HFD supplemented with CT drinking) for 8 weeks were investigated. Serum samples for clinical biochemistry and liver samples for histopathology and liquid chromatography-mass spectrometry-based metabolomic research were collected. Western blot and quantitative real-time PCR analyses were further used to measure the expression of several relevant enzymes together with perturbed metabolic pathways. Using analysis software, the CT treatment was found to significantly ameliorate the disturbance in 10 metabolic pathways. Combined metabolomic, Western blot, and quantitative real-time PCR analyses revealed that CT treatment significantly improved the glucose homeostasis by, on the one hand, through inhibiting the expression of gluconeogenic pathway key proteins glucose-6-phosphatase and phosphoenolpyruvate carboxykinase and, on the other hand, via regulating the mRNA or protein levels of the Krebs cycle critical enzymes (citrate synthase, succinate dehydrogenase complex, subunit A, flavoprotein, and dihydrolipoamide S-succinyltransferase). These results provide metabolic evidence of the complex pathogenic mechanism involved in hepatic insulin resistance and that the supplementation with CT improves insulin resistance at a global scale. Liquid chromatography-mass spectrometry-based metabolomics approaches are helpful to further understand diabetes-related mechanisms.

The Role of High Fat Diets and Liver Peptidase Activity in the Development of Obesity and Insulin Resistance in Wistar Rats

“…High fat diets have demonstrated the ability to be a good model of obesity and metabolic syndrome in laboratory animals models [6][7][8]56,58,59]. However, the efficiency in the use of energy also influences the development of obesity in rodents.…”

“…The efficacy of the current strategies of treatment for diseases that are caused by obesity is still not entirely satisfactory, and new approaches must be considered. Several studies have indicated relationships between the saturation of dietary fat and the concentrations of total plasma cholesterol and higher blood pressure [5], hepatic steatosis [6], adipose chronic inflammation [6], ectopic lipid deposition in the liver and brown fat [6], overweight [6,7], hyperinsulinemia [7], and hepatic insulin resistance [8]. However, high fat diets that are rich in monounsaturated fatty acids exert a protective role [9][10][11][12][13][14][15].High monounsaturated fatty acids diets also have demonstrated an effect on the secretion of the insulinotropic peptide GLP-1 (glucagon-like peptide 1) [16,17].…”

Okanin, effective constituent of the flower tea Coreopsis tinctoria, attenuates LPS-induced microglial activation through inhibition of the TLR4/NF-κB signaling pathways

“…The different types of tea, including green tea, red tea and black tea, originate from plants of the Camellia genus. Recently non- Camellia teas, as popular health supplements, have attracted more attention from both scientists and consumers12. C. tinctoria Nutt., known as “snow chrysanthemum” or “snow tea” is traditionally used as a non- Camellia tea by the Uyghur folk.…”

Metabolomic profiling reveals effects of marein on energy metabolism in HepG2 cells

“…Previous study showed that the flower tea C. tinctoria increases insulin sensitivity and regulates hepatic metabolism in rats fed a high-fat diet [22] . In this study, it had been showed that AC strongly improves glucose and lipid homeostasis disrupted by HFD in rats.…”

“…(Asteraceae), a traditionally used preparation for diabetes treatment in Portugal [20, 21] , is a plant native to North America that has spread worldwide. Our previous study showed that C. tinctoria increases insulin sensitivity and regulates hepatic metabolism in rats fed a high-fat diet [22] .Since these activities are closely related to metabolic regulation and IR, we tried to identify the protective effect of ethyl acetate extract of C. tinctoria Nutt (AC) on IR, and its possible mechanism of action. Chalcones (okanin and butein derivatives) are the main constituents of ethyl acetate extract of C. tinctoria and among them, identified Marein (okanin-4’-O-β-D-glucopyranoside) as the main metabolite [23] .…”