Oolong tea of different years protects high-fat diet-fed mice against obesity by regulating lipid metabolism and modulating the gut microbiota

Immature Citrus unshiu fruit extracts inhibit adipogenesis in 3T3-L1 adipocytes via AMPK and MAPK signaling pathways

In Korea, immature citrus fruits have been extensively explored for their potential utility as functional bio-health materials owing to their various bioactive properties. However, the specific mechanisms by which they exert inhibitory effects on adipogenesis remain unclear. Therefore, this study aimed to examine the anti-obesity effects of 70% ethanol extracts of immature Citrus unshiu fruits and their solvent fractions (n-hexane, ethyl acetate, n-butanol, and water) on 3T3-L1 cells, as well as to explore the underlying molecular mechanisms. Additionally, this study was conducted to identify the bioactive components responsible for the anti-obesity effects. Among the fractions, the hexane fraction exhibited the most potent inhibitory effect on lipid accumulation in 3T3-L1 cells without inducing cytotoxicity. Notably, this effect was concentration-dependent. This fraction also inhibited adipogenesis during the differentiation of 3T3-L1 preadipocytes by downregulating the expression of CCAAT/enhancer-binding proteins (C/EBP), peroxisome proliferator-activated receptor-γ (PPARγ), sterol regulatory element-binding protein (SREBP), fatty acid synthase (FAS), and fatty acid binding protein 4 (FABP4). Moreover, the hexane fraction modulated the activity of AMP-activated protein kinase (AMPK) and mitogen-activated protein kinase (MAPK), both of which play critical roles in lipid metabolism. Specifically, it induced AMPK activation while downregulating MAPK signaling. Phytochemical analysis identified phytol, hexatriacontane, tangeretin, and nobiletin as the main bioactive components responsible for the observed anti-obesity effects of ICE. Overall, our results revealed that ICE exhibited notable anti-obesity activity by targeting the AMPK and MAPK signaling pathways, highlighting its potential as a natural therapeutic agent for obesity management.

Gut microbiota and mycobiota change with feeding duration in mice on a high-fat and high-fructose diet

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD), formerly known as nonalcoholic fatty liver disease (NAFLD), is becoming the most common chronic liver disease. The gut microbiome is regarded to play a crucial role in MAFLD, but the specific changes of gut microbiome, especially fungi, in different stages of MAFLD are not well understood. This study aimed to observe the longitudinal changes of colon bacteria and fungi of mice at different feeding duration of a high-fat and high-fructose diet (HFHFD), and explore the association between the changes and the progression of MAFLD.

METHODS

Twenty-eight male C57BL6J mice were randomly assigned to the normal diet (ND) group and HFHFD group. At the 8th and 16th weeks, mice were sacrificed to compare the diversity, composition, and co-abundance network of bacteria and fungi in colon contents among groups.

RESULTS

HFHFD-8W mice exhibited increases in Candida and Dorea, and decreases in Oscillospira and Prevotella in comparison to ND-8W mice, HFHFD-16W mice had increases in Bacteroides, Candida, Desulfovibrio, Dorea, Lactobacillus, and Rhodotorula, and decreases in Akkermansia, Aspergillus, Sterigmatomyces, and Vishniacozyma in comparison to ND-16W mice. And compared to HFHFD-8W mice, HFHFD-16W mice had increases in Desulfovibrio, Lactobacillus, Penicillium, and Rhodotorula, and decreases in Talaromyces and Wallemia. Spearman and GEE correlation analysis revealed that Bacteroides, Candida, Desulfovibrio, and Lactobacillus positively correlated with NAFLD activity score (NAS).

CONCLUSION

Gut microbiota and mycobiota undergo diverse changes at different stages of MAFLD.

CLINICAL TRIAL NUMBER

Not applicable.

Effects of Mao tea from Nankun Mountain on nonalcoholic fatty liver disease in mice

Non-alcoholic fatty liver disease (NAFLD) poses a significant health threat due to its potential progression to liver fibrosis, cirrhosis, and even liver cancer. Without proper management, NAFLD can lead to severe complications and significantly impact overall health and longevity. This study explores the potential anti-steatosis effects of Nankun Mountain Mao tea (MT) on hepatic lipid accumulation using both in vitro and in vivo models. In vitro experiments reveal that MT reduces lipid accumulation in hepatocytes and counteracts hepatic steatosis induced by palmitic acid and oleic acid. In vivo investigations on high-fat diet (HFD)-fed and high-fat, fructose, and cholesterol (HFFC)-fed mice demonstrate that MT administration alleviates hepatic steatosis by reducing lipid accumulation, enhancing liver function, and mitigating inflammation. Transcriptomic analyses unveil the molecular mechanisms underlying the impact of MT on lipid metabolism and inflammation. It turns out that MT inhibits de novo lipid synthesis and NF-κB pathway against NAFLD. Furthermore, target prediction analysis identifies potential bioactive components group (BCG) within MT that may contribute to its anti-steatosis properties. Validation studies on primary hepatocytes confirm the effectiveness of these bioactive components in diminishing lipid accumulation and inflammation, suggesting their role in the therapeutic efficacy of MT against NAFLD.

Metabolomics analysis of flavor differences in Shuixian (Camellia sinensis) tea from different production regions and their microbial associations

Shuixian is renowned for its "rock flavor". However, the variations in Shuixian flavor are unclear, as the discussion mainly considers regional factors and overlooks the role of microorganisms. Sensory evaluation of Shuixian from three different regions (Zhengyan, Banyan, and Waishan) revealed that each had unique flavor characteristics: a woody aroma with slight acidity, a strong floral and fruity aroma with good freshness, and a distinct sweet aroma and sourness. Metabolomic analyses have revealed that 2-methylpyrazine was a crucial component of the woody aroma, whereas other metabolites contributed to sweet aroma, freshness, and acidity. Moreover, examinations of the relationship between flavor metabolites and microorganisms revealed that fungi had a more pronounced influence on the metabolite content of Shuixian. The study evaluated the role of fermentation microorganisms in shaping the flavor based on Shuixian flavor analyses, contributing to further research into the "rock flavor", as well as potential microbial interventions.

Differences of Typical Wuyi Rock Tea in Taste and Nonvolatiles Profile Revealed by Multisensory Analysis and LC-MS-Based Metabolomics

Wuyi Rock tea, specifically Shuixian and Rougui, exhibits distinct sensory characteristics. In this study, we investigated the sensory and metabolite differences between Shuixian and Rougui. Quantitative description analysis revealed that Rougui exhibited higher intensity in bitter, thick, harsh, and numb tastes, while Shuixian had stronger salty and umami tastes. Nontargeted metabolomics identified 151 compounds with 66 compounds identified as key differential metabolites responsible for metabolic discrimination. Most of the catechins and flavonoids were enriched in Rougui tea, while epigallocatechin-3,3'-di-O-gallate, epigallocatechin-3,5-di-O-gallate, gallocatechin-3,5-di-O-gallate, isovitexin, and theaflavanoside I were enriched in Shuixian tea. Catechins, kaempferol, quercetin, and myricetin derivatives were positively correlated with bitter taste and numb sensation. Sour taste was positively correlated to organic acids. Amino acids potentially contributed to salty and umami tastes. These results provide further insights into the taste characteristics and the relationship between taste attributes and specific metabolites in Wuyi Rock tea.

Design, synthesis and evaluation of 2-pyrimidinylindole derivatives as anti-obesity agents by regulating lipid metabolism

Obesity, a global pandemic posing a growing threat to human health, necessitates the development of effective and safe anti-obesity agents. Our previous studies highlighted the lipid-lowering effects of indolylquinazoline Bouchardatine and its derivatives. In this study, we employed scaffold hopping and simplification strategies to design and synthesize two new series derivatives by modifying the D ring. Extensive discussions have been conducted regarding the structure-activity relationship between lipid-lowering activity and the new compounds. These discussions have resulted in the discovery of 2-pyrimidinylindole derivatives as a promising scaffold for anti-obesity treatment. The new 2-pyrimidinylindole derivatives exhibited comparable lipid-lowering activity to the previously reported indolylquinazoline derivatives, including SYSU-3d and R17, with reduced toxicity. The most potent compound, 5a, demonstrated a larger therapeutic index, improved aqueous solubility and oral bioavailability compared to the previous lead compounds. In vivo evaluation indicated that 5a effectively reduced lipid accumulation in adipose tissue, improved glucose tolerance, and mitigated insulin resistance and liver function damage caused by a high-fat and high-cholesterol diet. Mechanism studies indicated that 5a may regulate lipid metabolism through the modulation of the PPARγ signaling pathway. Overall, our study has identified a highly active compound 5a, and provided the basis for further development of 2-pyrimidinylindole as a promising scaffold for obesity treatment.

Celastrol functions as an emerging manager of lipid metabolism: Mechanism and therapeutic potential

Lipid metabolism disorders are pivotal in the development of various lipid-related diseases, such as obesity, atherosclerosis, non-alcoholic fatty liver disease, type 2 diabetes, and cancer. Celastrol, a bioactive compound extracted from the Chinese herb Tripterygium wilfordii Hook F, has recently demonstrated potent lipid-regulating abilities and promising therapeutic effects for lipid-related diseases. There is substantial evidence indicating that celastrol can ameliorate lipid metabolism disorders by regulating lipid profiles and related metabolic processes, including lipid synthesis, catabolism, absorption, transport, and peroxidation. Even wild-type mice show augmented lipid metabolism after treatment with celastrol. This review aims to provide an overview of recent advancements in the lipid-regulating properties of celastrol, as well as to elucidate its underlying molecular mechanisms. Besides, potential strategies for targeted drug delivery and combination therapy are proposed to enhance the lipid-regulating effects of celastrol and avoid the limitations of its clinical application.