Shulin Wang

Background: Obesity has emerged as a significant public health challenge largely attributed to excessive dietary fat consumption. A growing body of evidence indicates that soluble dietary fiber (SDF) can prevent high-fat-diet (HFD)-induced obesity by modulating the gut microbiota. Our previous studies have shown that SDF derived from highland barley bran exhibits favorable lipid-lowering activity in vitro, but its lipid-lowering effect in vivo remains to be elucidated. Methods: This study aimed to investigate the lipid-lowering effects of SDF from highland barley bran in HFD-fed mice based on the gut microbiota. Mice were fed an HFD, and the intervention effects of SDF on hepatic lipid metabolism and its underlying molecular mechanisms were systematically evaluated using liver lipidomics, 16S rDNA sequencing, molecular biological techniques, and fecal microbiota transplantation (FMT). Results: Liver lipidomics analysis revealed that potential lipid biomarkers responsive to barley bran-derived SDF included phosphatidylethanolamines (PE, 18:2–20:3), phosphatidylserine (PS, 18:0–18:2), and PS (18:1–22:3). Furthermore, SDF modulated the composition and structure of the gut microbiota in HFD-fed mice. Notably, SDF increased the abundance of short-chain fatty acid (SCFA)-producing bacteria, particularly Dubosiella, as well as elevated SCFA levels. Conclusions: The increase in SCFAs activated the hepatic AMP-activated protein kinase α (AMPK) signaling pathway, thereby ameliorating HFD-induced disturbances in lipid metabolism, reducing hepatic lipid accumulation, and lowering serum lipid concentrations.

This study employed wild sea buckthorn (Hippophae rhamnoides L.) fruits harvested in Qinghai Province as experimental material. Following compositional analysis of their flavonoids, the antibacterial efficacy and mechanistic pathways of flavonoids in sea buckthorn against Helicobacter pylori (H. pylori) were systematically examined through in vitro and animal model experiments. The results showed that the main flavonoids in sea buckthorn were rutin, quercetin-3-O-glucoside, quercetin, catechin, isorhamnetin, kaempferol-3-O-glucoside, kaempferol and epicatechin. Among them, quercetin, isorhamnetin and kaempferol had strong inhibitory activity against H. pylori. In vitro, sea buckthorn flavonoids inhibited the growth of H. pylori through multiple mechanisms: inducing morphological transformation from rod-shaped to spherical bacteria, promoting cell shrinkage and rupture, disrupting the cell membrane to cause leakage of intracellular macromolecules, increasing membrane permeability, and suppressing urease activity. Sea buckthorn flavonoids exert therapeutic effects on H. pylori-infected mice through multiple mechanisms, including the alleviation of gastric mucosal inflammation via the Nuclear Factor KappaB (NF-κB) signaling pathway, the down-regulation of gastrin-17 (GAS17) to suppress gastric acid production, and the up-regulation of epidermal growth factor (EGF) expression to promote gastric mucosal repair and modulate the composition of gastric microbiota. This study systematically elucidated the anti-H. pylori activity and antibacterial mechanisms of flavonoids derived from sea buckthorn fruits, providing a theoretical basis for the screening of natural antibacterial agents from this plant source.

Characterization of the structure and pharmacological activity of Berberis dasystachya Maxim., a traditional Tibetan medicinal and edible fruit, has not yet been reported. In this study, central composite design (CCD) combined with response surface methodology (RSM) was applied to optimize the extraction conditions of B. dasystachya oil (BDSO) using the supercritical carbon dioxide (SC-CO₂) extraction method, and the results were compared with those obtained by the petroleum ether extraction (PEE) method. The chemical characteristics of BDSO were analyzed, and its antioxidant activity and in vitro cellular viability were studied by DPPH, ABTS, reducing power assay, and MTT assay. The results showed that the maximum yield of 12.54 ± 0.56 g/100 g was obtained at the optimal extraction conditions, which were: pressure, 25.00 MPa; temperature 59.03 °C; and CO₂ flow rate, 2.25 SL/min. The Gas chromatography (GC) analysis results showed that BDSO extracted by the SC-CO₂ method had higher contents of unsaturated fatty acids (85.62%) and polyunsaturated fatty acids (57.90%) than that extracted by the PEE method. The gas chromatography used in conjunction with ion mobility spectrometry (GC–IMS) results showed that the main volatile compounds in BDSO were aldehydes and esters. BDSO also exhibited antioxidant ability in a dose-dependent manner. Moreover, normal and cancer cells incubated with BDSO had survival rates of more than 85%, which indicates that BDSO is not cytotoxic. Based on these results, the BDSO extracted by the SC-CO₂ method could potentially be used in other applications, e.g., those that involve using berries of B. dasystachya.

In order to explore relationship between the yellow fat and β-carotene metabolism in yaks, contents of β-carotene and retinol in tissues, serum and digestive tract contents were analysed at periods of rich and deficient nutrition. Expressions of β-carotene 15, 15’-monooxygenase 1 (BCO1)...

Differences in the content of nine phenols and the antioxidant capacity of Ribes stenocarpum Maxim (RSM) fruits at different stages of maturity were investigated, and the extraction process of polyphenols from RSM was also optimized using Box-Behnken design method. Results showed that the content of the nine phenols varied considerably at different ripening stages; catechin, chlorogenic acid, coumaric acid, and ferulic acid were abundant in immature fruits but decreased with fruit ripening, whereas the levels of rosemary acid and querctin acid were low in immature fruits and increased with time, reaching the highest value after the fruit was completely mature. The phenols extracted from RSM fruits possessed good antioxidant activities for effective and rapid scavenging of DPPH and ABTS free radicals, as well as intracellular ROS. Analysis of the phenols content at different maturity stages indicated that the unripe fruits had significantly higher polyphenols content than mature fruits. Consequently, unripe fruits possessed higher antioxidant activities. According to the overall results of the extraction process optimization, the selected optimal conditions for extracting polyphenols from RSM were as follows: extraction time, 95 min; solvent concentration, 60%; ratio of sample to solvent, 1:25.