As a sugar additive, fructose is widely used in processed foods and beverages. Excessive fructose consumption can cause hepatic steatosis and dyslipidemia, leading to the development of metabolic syndrome. Recent research revealed that fructose-induced nonalcoholic fatty liver disease (NAFLD) is related to several pathological processes, including: (1) augmenting lipogenesis; (2) leading to mitochondrial dysfunction; (3) stimulating the activation of inflammatory pathways; and (4) causing insulin resistance. Cellular signaling research indicated that partial factors play significant roles in fructose-induced NAFLD, involving liver X receptor (LXR)α, sterol regulatory element binding protein (SREBP)-1/1c, acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), stearoyl-CoA desaturase (SCD), peroxisome proliferator–activated receptor α (PPARα), leptin nuclear factor-erythroid 2-related factor 2 (Nrf2), nuclear factor kappa B (NF-κB), tumor necrosis factor α (TNF-α), c-Jun amino terminal kinase (JNK), phosphatidylinositol 3-kinase (PI3K) and adenosine 5′-monophosphate (AMP)-activated protein kinase (AMPK). Until now, a series of natural products have been reported as regulators of NAFLD in vivo and in vitro. This paper reviews the natural products (e.g., curcumin, resveratrol, and (−)-epicatechin) and their mechanisms of ameliorating fructose-induced NAFLD over the past years. Although, as lead compounds, natural products usually have fewer activities compared with synthesized compounds, it will shed light on studies aiming to discover new drugs for NAFLD.
Hyperuricemia is an important risk factor of chronic kidney disease, metabolic syndrome and cardiovascular disease. We aimed to assess the time-feature relationship of hyperuricemia mouse model on uric acid excretion and renal function. A hyperuricemia mouse model was established by potassium oxonate (PO) and adenine for 21 days. Ultra Performance Liquid Chromatography was used to determine plasma uric acid level. Hematoxylin-eosin staining was applied to observe kidney pathological changes, and Western blot was used to detect renal urate transporters’ expression. In hyperuricemia mice, plasma uric acid level increased significantly from the 3rd day, and tended to be stable from the 7th day, and the clearance rate of uric acid decreased greatly from the 3rd day. Further study found that the renal organ of hyperuricemia mice showed slight damage from the 3rd day, and significantly deteriorated renal function from the 10th day. In addition, the expression levels of GLUT9 and URAT1 were upregulated from the 3rd day, while ABCG2 and OAT1 were downregulated from the 3rd day, and NPT1 were downregulated from the 7th day in hyperuricemia mice kidney. This paper presents a method suitable for experimental hyperuricemia mouse model, and shows the time-feature of each index in a hyperuricemia mice model.
Diabetic kidney disease (DKD) occurs in 25–40% of patients with diabetes. Individuals with DKD are at a significant risk of progression to end-stage kidney disease morbidity and mortality. At present, although renal function-decline can be retarded by intensive glucose lowering and strict blood pressure control, these current treatments have shown no beneficial impact on preventing progression to kidney failure. Recently, in addition to control of blood sugar and pressure, a dietary approach has been recommended for management of DKD. Amino acids (AAs) are both biomarkers and causal factors of DKD progression. AA homeostasis contributes to renal hemodynamic response and glomerular hyperfiltration alteration in diabetic patients. This review discusses the links between progressive kidney dysfunction and the metabolic homeostasis of histidine, tryptophan, methionine, glutamine, tyrosine, and branched-chain AAs. In addition, we emphasize the regulation effects of special metabolites on DKD progression, with a focus on causality and potential mechanisms. This paper may offer an optimized protein diet strategy with concomitant management of AA homeostasis to reduce the risks of DKD in a setting of hyperglycemia.
Rosmarinus officinalis Linn. is a kind of medicinal and edible homologous plant, which is popular in the Mediterranean region with a significant effect on mind tranquilization, anti-oxidation, and metabolic improvement. However, the hypolipidemic effects and mechanism of rosemary ethanol extract (RO) and their metabolites are less known. In this study, the hypolipidemic effects of RO and its active compounds were clarified. The results showed that RO, rosmarinic acid (RA) and carnosic acid (CA) significantly reduced the contents of liver triglyceride (TG), total cholesterol (TC), free fatty acids (FFA) and improved cell hypertrophy, vacuolation, and cell necrosis in the liver of orotic acid induced non-alcoholic fatty liver disease (NAFLD) model rats. The mechanism and related pathways of RO and its main metabolites against lipid disorder were related to the up-regulation of the phosphorylation of adenosine 5′-monophosphate(AMP)-activated protein kinase (AMPK) and the inhibition of the sterol regulatory element binding protein-1c (SREBP-1c) cracking into the nucleus, following the down-regulation of fatty acid synthesis. In conclusion, our study demonstrates that RA and CA are active substances of RO, and provides scientific evidence to support functional food product development for improving NAFLD.
Constipation is a common bowel disease in adults with the symptoms of dry stool or difficulty passing stool. Compared with medication therapy, patients show more compliance with the diet therapy, and thus the diet therapy normally exhibits better therapeutic effect. Allium mongolicum Regel s a perennial herb of Liliaceae native to Mongolia, Kazakhstan, and China, which is traditionally used for constipation. In this paper, we partly clarify the effectiveness of A. mongolicum on constipation from two aspects, including maintaining colon water content and increasing intestinal transit. In loperamide-induced constipation mice model, nine days oral administration of A. mongolicum 50% ethanolic extract increased luminal side water content and regulated intestinal movement rhythm to normalize stools. The activity at least partly related to down-regulation of colon aquaporins 3 (AQP3) expression, and up-regulation and activation of G protein alpha (Gα) and phosphoinositide 3-kinases (PI3K). Further, activities on intestine movements were tested using compounds isolated from A. mongolicum. Three kinds of major flavonoids significantly increased cellular calcium flux in HCT116 cells and promoted mice intestine smooth muscle contraction. The activity may be related to M choline receptor, μ opioid receptor, 5-HT3 receptor, and inositol 1,4,5-trisphosphate (IP3) receptor.
Diabetic kidney disease (DKD) is a common and devastating complication in diabetic patients, which is recognized as a large and growing problem leading to end-stage kidney disease. As dietary-mediated therapies are gradually becoming more acceptable to patients with DKD, we planned to find active compounds on preventing DKD progression from dietary material. The present paper reports the renoprotective properties and underlying mechanisms of ginsenoside compound K (CK), a major metabolite in serum after oral administration of ginseng. CK supplementation for 16 weeks could improve urine microalbumin, the ratio of urinary albumin/creatinine and renal morphological abnormal changes in db/db mice. In addition, CK supplementation reshaped the gut microbiota by decreasing the contents of Bacteroides and Paraprevotella and increasing the contents of Lactobacillu and Akkermansia at the genus level, as well as reduced histidine-derived microbial metabolite imidazole propionate (IMP) in the serum. We first found that IMP played a significant role in the progression of DKD through activating toll-like receptor 4 (TLR4). We also confirmed CK supplementation can down-regulate IMP-induced protein expression of the TLR4 signaling pathway in vivo and in vitro. This study suggests that dietary CK could offer a better health benefit in the early intervention of DKD. From a nutrition perspective, CK or dietary material containing CK can possibly be developed as new adjuvant therapy products for DKD.