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OBJECTIVE: To reveal the effects and related mechanisms of chlorogenic acid (CGA) on intestinal glucose homeostasis. METHODS: Forty male Sprague-Dawley rats were randomly and equally divided into four groups: normal chow (NC), high-fat diet (HFD), HFD with low-dose CGA (20 mg/kg, HFD-LC), and HFD with high-dose CGA (90 mg/kg, HFD-HC). The oral glucose tolerance test was performed, and fast serum insulin (FSI) was detected using an enzyme-linked immunosorbent assay. The mRNA expression levels of glucose transporters (Sglt-1 and Glut-2) and proglucagon (Plg) in different intestinal segments (the duodenum, jejunum, ileum, and colon) were analyzed using quantitative real-time polymerase chain reaction. SGLT-1 protein and the morphology of epithelial cells in the duodenum and jejunum was localized by using immunofluorescence. RESULTS: At both doses, CGA ameliorated the HFD-induced body weight gain, maintained FSI, and increased postprandial 30-min glucagon-like peptide 1 secretion. High-dose CGA inhibited the HFD-induced elevation in Sglt-1 expression. Both CGA doses normalized the HFD-induced downregulation of Glut-2 and elevated the expression of Plg in all four intestinal segments. CONCLUSION: An HFD can cause a glucose metabolism disorder in the rat intestine and affect body glucose homeostasis. CGA can modify intestinal glucose metabolism by regulating the expression of intestinal glucose transporters and Plg, thereby controlling the levels of blood glucose and insulin to maintain glucose homeostasis.
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Ácido Clorogénico/farmacología , Dieta Alta en Grasa/efectos adversos , Mucosa Intestinal/metabolismo , Intestinos/efectos de los fármacos , Aumento de Peso/efectos de los fármacos , Animales , Péptido 1 Similar al Glucagón/metabolismo , Glucosa/metabolismo , Prueba de Tolerancia a la Glucosa , Transportador de Glucosa de Tipo 2/metabolismo , Homeostasis , Insulina/sangre , Masculino , Proglucagón/metabolismo , Distribución Aleatoria , Ratas Sprague-Dawley , Transportador 1 de Sodio-Glucosa/metabolismoRESUMEN
BACKGROUND: Chlorogenic acids (CGAs) are widely distributed in plant material, including foods and beverages. 5-Caffeoylquinic acid (5-CQA) is the most studied CGA, but the mechanism of its hypolipidaemic effect remains unclear. This study aimed to determine the effect of 5-CQA on lipid metabolism in the liver of Sprague-Dawley rats fed a high-fat diet (HFD). RESULTS: 5-CQA suppressed HFD-induced increases in body weight and visceral fat-pad weight, serum lipid levels, and serum and hepatic free fatty acids in a dose-dependent manner. Real-time polymerase chain reaction revealed that 5-CQA altered the mRNA expression of the transcription factors peroxisome proliferator-activated receptor α (PPARα) and liver X receptor α (LXRα) and target genes involved in hepatic fatty acid uptake, ß-oxidation, fatty acid synthesis, and cholesterol synthesis. Moreover, hepatic tissue sections from HFD-fed rats showed many empty vacuoles, suggesting that liver cells were filled with more fat droplets. However, 5-CQA significantly ameliorated this effect. CONCLUSION: 5-CQA may improve lipid metabolism disorders by altering the expression of PPARα and LXRα, which are involved in multiple intracellular signalling pathways.
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Fármacos Antiobesidad/uso terapéutico , Ácido Clorogénico/análogos & derivados , Suplementos Dietéticos , Hígado/metabolismo , Obesidad/prevención & control , Receptores Nucleares Huérfanos/antagonistas & inhibidores , PPAR alfa/agonistas , Ácido Quínico/análogos & derivados , Adiposidad , Animales , Fármacos Antiobesidad/administración & dosificación , Antioxidantes/administración & dosificación , Antioxidantes/uso terapéutico , Ácido Clorogénico/administración & dosificación , Ácido Clorogénico/uso terapéutico , Dieta Alta en Grasa/efectos adversos , Ácidos Grasos no Esterificados/sangre , Ácidos Grasos no Esterificados/metabolismo , Regulación de la Expresión Génica , Hiperlipidemias/etiología , Hiperlipidemias/metabolismo , Hiperlipidemias/patología , Hiperlipidemias/prevención & control , Hipolipemiantes/administración & dosificación , Hipolipemiantes/uso terapéutico , Metabolismo de los Lípidos , Lípidos/sangre , Hígado/patología , Receptores X del Hígado , Masculino , Obesidad/etiología , Obesidad/metabolismo , Obesidad/patología , Receptores Nucleares Huérfanos/genética , Receptores Nucleares Huérfanos/metabolismo , PPAR alfa/genética , PPAR alfa/metabolismo , Ácido Quínico/administración & dosificación , Ácido Quínico/uso terapéutico , Distribución Aleatoria , Ratas Sprague-DawleyRESUMEN
The chemical structure of sinoacutine is formed by a phenanthrene nucleus and an ethylamine bridge. Because it has a similar parent structure to morphine, it is subdivided into morphinane. At present, all reports have pointed out that the basic skeleton of morphine alkaloids is salutaridine (the isomer of sinoacutine), which is generated by the phenol coupling reaction of (R)-reticuline. This study shows that the biosynthetic precursors of sinoacutine and salutaridine are different. In this paper, the sinoacutine synthetase (SinSyn) gene was cloned from Sinomenium acutum and expressed SinSyn protein. Sinoacutine was produced by SinSyn catalyzed (S)-reticuline, according to the results of enzyme-catalyzed experiments. The optical activity, nuclear magnetic resonance, and mass spectrum of sinoacutine and salutaridine were analyzed. The classification and pharmacological action of isoquinoline alkaloids were discussed. It was suggested that sinoacutine should be separated from morphinane and classified as sinomenine alkaloids.
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Alcaloides , Morfinanos , Estructura Molecular , Morfinanos/química , Morfinanos/metabolismo , Morfinanos/farmacología , Alcaloides/farmacología , Derivados de la MorfinaRESUMEN
Cold acclimation is a complex biological process leading to the development of freezing tolerance in plants. In this study, we demonstrated that cold-induced expression of protease inhibitor FmASP in a Citrus-relative species kumquat [Fortunella margarita (Lour.) Swingle] contributes to its freezing tolerance by minimizing protein degradation. Firstly, we found that only cold-acclimated kumquat plants, despite extensive leaf cellular damage during freezing, were able to resume their normal growth upon stress relief. To dissect the impact of cold acclimation on this anti-freezing performance, we conducted protein abundance assays and quantitative proteomic analysis of kumquat leaves subjected to cold acclimation (4°C), freezing treatment (-10°C) and post-freezing recovery (25°C). FmASP (Against Serine Protease) and several non-specific proteases were identified as differentially expressed proteins induced by cold acclimation and associated with stable protein abundance throughout the course of low-temperature treatment. FmASP was further characterized as a robust inhibitor of multiple proteases. In addition, heterogeneous expression of FmASP in Arabidopsis confirmed its positive role in freezing tolerance. Finally, we proposed a working model of FmASP and illustrated how this extracellular-localized protease inhibitor protects proteins from degradation, thereby maintaining essential cellular function for post-freezing recovery. These findings revealed the important role of protease inhibition in freezing response and provide insights on how this role may help develop new strategies to enhance plant freezing tolerance.
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Obesity, considered as a consequence of overnutrition, sustains a low-degree inflammatory state and results in insulin-resistance and type 2 diabetes. Here, we investigated the anti-inflammatory effects of 5-caffeoylquinic acid (5-CQA) in high-fat diet-induced obese rats. Serum interleukin (IL)-6, monocyte chemotactic protein 1 (MCP-1), tumor necrosis factor-alpha (TNF-α), total cholesterol (TC), triglyceride (TG), and free fatty acid (FFA) levels were determined. Expression of genes related to TG metabolism, macrophage biomarkers, and inflammation was assessed by real-time PCR. Protein expression of NF-κB, PPARγ2, and phosphorylated IκBα was evaluated by western blotting, and the histology of adipose tissue was examined. Supplementation of the rat diet with 5-CQA reduced obesity development, macrophage infiltration, and steatosis. Additionally, 5-CQA decreased the expression of NF-κB and downstream inflammatory cytokines, but increased the expression of PPARγ2, in a dose-dependent manner. Thus, 5-CQA improved obesity and obesity-related metabolic disturbances via PPARγ2 and the NF-κB signaling pathway.