Rubus chingii var. suavissimus alleviates high-fat diet-induced lipid metabolism disorder via modulation of the PPARs/SREBP pathway in Syrian golden hamsters

Rhamnogalacturonan-I enriched pectin from steamed ginseng ameliorates lipid metabolism in type 2 diabetic rats via gut microbiota and AMPK pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Panax ginseng C. A. Meyer (Ginseng) has traditionally been used to treat diabetes. Polysaccharide is the main active component of ginseng, and has been proved to have hypoglycaemic and hypolipidaemic effects, but its mechanism remains unclear.

AIM OF THE STUDY

This study aimed to evaluate the effect and the potential mechanism of rhamnogalacturonan-I enriched pectin (GPS-1) from steamed ginseng on lipid metabolism in type 2 diabetes mellitus (T2DM) rats.

MATERIALS AND METHODS

GPS-1 was prepared by water extraction, ion-exchange and gel chromatography. High-glucose/high-fat diet combined with streptozotocin was used to establish T2DM rat models, and lipid levels in serum and liver were tested. 16S rRNA sequencing and gas chromatography-mass spectrometry were used to detect the changes of gut microbiota and metabolites. The protein and mRNA levels of lipid synthesis-related genes were detected by Western blot and quantitative real-time polymerase chain reaction.

RESULTS

The polyphagia, polydipsia, weight loss, hyperglycaemia, hyperlipidaemia and hepatic lipid accumulation in T2DM rats were alleviated after GPS-1 intervention. GPS-1 modulated the gut microbiota composition of T2DM rats, increased the levels of short-chain fatty acids, and promoted the secretion of glucagon-like peptide-1 and peptide tyrosine tyrosine. Further, GPS-1 activated AMP-activated protein kinases, phosphorylated acetyl-CoA carboxylase, reduced the expression of sterol regulatory element-binding protein-1c and fatty acid synthases in T2DM rats.

CONCLUSIONS

The regulation effects of GPS-1 on lipid metabolism in T2DM rats are related to the regulation of gut microbiota and activation of AMP-activated protein kinase pathway.

Targeting of gallbladder megalin receptors with DHA-conjugated limonene albumin nanoparticles

Gallbladder stones are a major pathogenic factor leading to cholecystitis, and it is increasingly important to explore innovative drug delivery methods for gallstones. In the present study, docosahexaenoic acid-coupled limonene bovine serum albumin nanoparticles (LIM-DHA-BSA-NPs) were constructed. The LIM-DHA-BSA-NPs are spherical structures, and the distribution was relatively uniform, and, more importantly, it has low cytotoxicity and good safety. The LIM-DHA-BSA-NPs solution shows higher uptake rates by RAW264.7 cells when compared with free limonene (LIM). The fluorescence intensity of FITC-modified BSA NPs was significantly higher than that of free FITC, which further indicated that the uptake of DHA-conjugated BSA NPs by RAW264.7 cells was stronger than that of the free drugs. Moreover, the in vivo distribution experiment showed that the enrichment of DiD-loaded BSA NPs in the gallbladder was significantly enhanced when compared with that of free DiD. The semi-quantitative fluorescence intensity results showed that the uptake of DiD-DHA-BSA-NPs was 4.5 times higher when compared with the free DiD. It is preliminarily shown that the DHA-conjugated BSA NPs that were constructed, have an ability to target the gallbladder. Furthermore, the Pearson colocalization coefficient R_coloc from in vivo colocalization results indicates that the DHA-BSA-NPs had a good colocalization effect on the gallbladder epithelial cells (GBECs). In addition, the LIM-DHA-BSA-NPs solution not only significantly reduced the concentration of nitric oxide (NO) secreted by inflammatory model cells and the number of peripheral blood leukocytes in guinea pigs with cholecystitis, but also significantly decreased the activities of the aspartate transaminase (AST), alkaline phosphatase (ALP), alanine aminotransferase (ALT), glutamyl endopeptidase (GGT), total bile acid (TBA), and total bilirubin (TBIL) enzymes. Collectively, the LIM-DHA-BSA-NPs could be used as an effective anti-inflammatory agent at the cellular and animal levels. This experiment, for the first time, showed that DHA-conjugated BSA NPs could be absorbed into GBECs by megalin receptor-mediated endocytosis and then they exert an anti-cholecystitis effect because of the LIM. The active uptake of DHA-conjugated BSA NPs by the megalin receptors of the GBECs is expected to become an effective therapeutic strategy for cholecystolithiasis.

Integrating Constituents Absorbed into Blood, Network Pharmacology, and Quantitative Analysis to Reveal the Active Components in Rubus chingii var. suavissimus that Regulate Lipid Metabolism Disorder

Rubus chingii var. suavissimus (S. K. Lee) L. T. Lu (RS)—a sweet plant also known as Tiancha distributed in the south of China where it is used as a beverage—recently gained extensive attention as adjuvant therapy of diabetes and hypertension. Although pharmacological studies indicate that RS has beneficial effects in regulating lipid metabolism disorder characteristics, the active chemicals responsible for this effect remains unclear. The present study aims to predict the effective substances of RS on regulating lipid metabolism disorder through the analysis of the chemical profile of RS, the absorbed prototype components in rat plasma, and network pharmacology. Also, a UPLC method able to quantify the screened potential effective chemicals of RS products was established. First, a total of 69 components—including diterpene, triterpenoids, flavonoids, polyphenols, and lignans—were systematically characterized in RS. Of those, 50 compounds were detected in the plasma of rats administered with RS extract. Through network pharmacology, 9 potential effective components, 71 target genes, and 20 pathways were predicted to be involved in RS-mediated regulation of lipid metabolism disorder. The quantitative analysis suggested that the contents of potential effective components varied among samples from different marketplaces. In conclusion, the presented results provide a chemical basis for further research of Rubus chingii var. suavissimus.