Mechanism of action of buckwheat quercetin in regulating lipid metabolism and intestinal flora via Toll-like receptor 4 or nuclear factor κB pathway in rats on a high-fat diet.

OBJECTIVES: Buckwheat quercetin (QUE) was used as a dietary supplement to investigate the mechanism of QUE on the regulation of lipid metabolism and intestinal flora in hyperlipidemic rats. METHODS: Here, using a high-fat diet-induced hyperlipidemia model, the intervention was carried out by gavage of QUE at doses of 50, 100, and 200 mg/kg. Serum lipid levels, liver biochemical parameters, and histopathologic changes in the liver and intestinal microorganisms were measured in rats by enzyme-linked immunosorbent assay, hematoxylin-eosin, and high-throughput sequencing, respectively. RESULTS: Our results found that QUE, at a dose of 200 mg/kg, significantly reduced body weight, liver index, and lipid levels in rats (P < 0.05); improved hepatic oxidative stress; and repaired liver injury. In addition, the upregulation of beneficial bacteria, such as christensenellaceae and Bifidobacterium, in the organism increased the content of short-chain fatty acids, thus interfering with intestinal pH and improving the intestinal environment, while downregulating the relative abundance of Proteobacteria and Eubacterium_coprostanoligenes_group, and regulating the overproduction of butyrate. The real-time fluorescence quantitative polymerase chain reaction results found that QUE inhibited the expression of Toll-like receptor 4 (TLR4) and nuclear factor κB (NF-κB) mRNA content and blocked the activation of the TLR4/NF-κB signaling pathway, thus affecting the downregulation of lipid levels and restoring intestinal homeostasis. CONCLUSIONS: A QUE dose of 200 mg/kg may improve lipid levels and the composition of intestinal flora through the TLR4/NF-κB pathway, suggesting that proteobacteria and christensenellaceae abundance changes may be biomarkers of potential diseases.

[Risk Assessment Method of Non-point Source Pollution Output for Watershed Using High Resolution Data].

In recent years, non-point source pollution has become the main cause of water quality deterioration in some reservoirs in China. Taking the Panjiakou Reservoir as an example, the classical output risk model was improved by introducing a precipitation factor and terrain factor. Combined with high-resolution satellite precipitation products (GPM) and GF-6 satellite images, a high-resolution data-driven risk assessment method for non-point source pollution output was established to study the temporal and spatial distribution characteristics of non-point source pollution output risk in the Panjiakou Reservoir basin. The results showed that the non-point source pollution output risk was high in the study area in 2018. The areas with higher and highest risk of nitrogen pollution output accounted for approximately 70.6% of the total watershed area, whereas the higher risk of phosphorus pollution output accounted for approximately 21.9%. The temporal and spatial distribution characteristics of non-point source pollution output risk in the Panjiakou Reservoir basin were analyzed. It was found that the non-point source pollution output risk in the Panjiakou Reservoir basin increased first and then decreased from April to September. This was consistent with the spatial and temporal distribution of precipitation in the basin. Combined with the analysis of land use distribution characteristics, the upstream area of the basin was mainly cultivated land, whereas cities were concentrated in the downstream portion of the basin. Affected by agricultural production and human activities, the risk of non-point source pollution output was higher in these regions. In view of the temporal and spatial distribution characteristics of non-point source pollution output risk, it is necessary to formulate a reasonable agricultural fertilization method, plan the landscape layout of source-sinks, and construct vegetation buffer zones.