Instant Dark Tea Alleviates Hyperlipidaemia in High-Fat Diet-Fed Rat: From Molecular Evidence to Redox Balance and Beyond

Abstract

Instant dark tea (IDT) is a new product gaining increasing attention because it is convenient and can endow significant health benefit to consumers, which is partially attributed to its high concentration of functional ingredients. However, the molecular mechanism underlying its regulatory effect on hyperlipidaemia is rarely studied. In this study, we performed omics and molecular verification in high-fat diet (HFD)-fed rat, aiming to reveal the mechanism and provide molecular evidence. The results showed that the major bioactive components in IDT were 237.9 mg/g total polysaccharides, 336.6 mg/g total polyphenols, and 46.9 mg/g EGCG. Rats fed with IDT (0.27–0.54 g/kg for 12 weeks) significantly reduced the body weight and TC, TG, LDL-C, blood glucose, and MDA and induced the level of serum HDL-C and also the levels of liver SOD, CAT, GSH-Px, and Nrf2, compared to HFD group. For molecular mechanism study, HIDT feeding had significant impact on the gene expressions of biomarkers in lipogenesis (FABP, CD36, SCD1, Cyp4a1, and Kcnn2), lipid oxidation (PPARγ), and glucose glycolysis (Gck and ENO2) in liver tissue. Moreover, gut microbiome study found that rats fed with IDT dramatically modified the gut microbial species at the family level, such as suppressing the increase abundance of Proteobacteria and Firmicutes induced by HFD. HIDT significantly boosted the relative composition of beneficial bacterium Akkermansia and Rikenellaceae_RC9_gut_group and decreased the relative abundance of the harmful bacterium Ruminococcaceae_UCG-005 and Ruminiclostridium_9, compared to HFD (p < 0.01). Correlation analysis between microbiome and animal indicators found that seven genera including Akkermansia, Clostridiales, Lachnospiraceae, Lachnospiraceae_UCG-010, Ruminiclostridium_9, Ruminococaceae-UCG-005, and Ruminocuccus_1 were found as potential biomarkers that were strongly correlated with oxidative stress and metabolism genes. For instance, Ruminococcaceae_UCG-005 was significantly correlated with body weight, TG, HDL-C, Nfr2, FABP3, SCD1, Cyp4a1, and Kcnn2. Collectively, the above data obtained in this study had provided the primary molecular evidence for the molecular mechanism and brought in novel insights based on omics for the regulatory effect of IDT on hyperlipidaemia.

How do living conditions affect the gut microbiota of endangered Père David’s deer (Elaphurus davidianus)? Initial findings from the warm temperate zone

“…It has been shown that adult females invest larger amounts of energy reserves and consume food to produce offspring ( Moyes et al, 2006 ). In this study, the abundances of Rikenellaceae_RC9_gut_group and Phascolarctobacterium were significantly higher in females than in males, promoting host nutrient absorption and health as mentioned previously ( Chen et al, 2021 ; Qin et al, 2022 ). Furthermore, the results showed that the abundances of both the phylum Verrucomicrobiota and the genus norank_o_WCHB1-41 belonging to this phylum were significantly higher in females than in males.…”

“…Thus, this diet structure led to the enrichment of Bacteroidota ( Zhao et al, 2019 ), which are involved in the degradation of macromolecular compounds such as proteins and carbohydrates ( Jami, White & Mizrahi, 2014 ; Hu et al, 2017 ). For example, Rikenellaceae_RC9_gut_group the dominant genera in captive individuals, is beneficial bacteria in the gut which promote host health and degradation of structural carbohydrates including lignin and cellulose ( Zened et al, 2013 ; Qin et al, 2022 ).…”

Hyperglycemia in Pregnancy-Associated Oxidative Stress Augments Altered Placental Glucose Transporter 1 Trafficking via AMPKα/p38MAPK Signaling Cascade

“…In addition, the antioxidant genes (SOD, catalase, and GSH-Px) were decreased, while biomarkers of glucose glycolysis (Gck and Eno2) were overexpressed in high-fat-fed rats. This could be reversed by instant dark tea intervention [ 58 ]. Summarily, the new transcription factors played potential roles in the regulation of OS induced by hyperglycemia and provided evidence for further basic research.…”

The hypolipidemic mechanism of chrysanthemum flavonoids and its main components, luteolin and luteoloside, based on the gene expression profile

“…Studies have shown that the GCK RS1799884 mutation is associated with a higher incidence of gestational diabetes mellitus (GDM) in the Chinese population ( 21 ). Its expression is also associated with hyperlipidemia, and the molecular mechanism of the regulation of hyperlipidemia by instant dark tea (IDT) has been demonstrated in rats fed with a high-fat diet and is related to the significant influence on the expression of glycoly-related genes such as GCK ( 22 ). Isoprene diphosphate isomerase (IDI) is involved in the biosynthesis of isoprene-like cholesterol, and there are two subtypes in humans, namely, IDI1 and IDI2 ( 23 ).…”