Quercetin 3-O-glucuronide-rich lotus leaf extract promotes a Brown-fat-phenotype in C3H10T1/2 mesenchymal stem cells

The lipase inhibitory effect of mulberry leaf phenolic glycosides: The structure-activity relationship and mechanism of action

The present study found for the first time that phenolic glycosides were an important material basis for mulberry leaves to inhibit lipase. The corresponding IC50 for hyperoside, rutin, astragalin and quercetin were 68, 252, 385 and 815 μg/mL respectively. The inhibitory effect was ranked as monoglycosides > phenolic hydroxyl groups > disaccharides on the benzone ring. Hyperoside bound to lipase in competitive inhibition type with one binding site, while the others bound to lipase in a mixed inhibition type by two similar sites. All four compounds altered the microenvironment and secondary conformation of lipase through static quenching. The docking score, stability, and binding energy were consistent with the compound inhibitory activity. The main binding between compounds and lipase amino acid residues were spontaneously though hydrophobic interactions and hydrogen bonding. The strong hydrogen bonds formed with SER-152 inside the lipase pocket, might be important for the strong inhibitory activity of hyperoside.

Dietary polyphenols regulate appetite mechanism via gut-brain axis and gut homeostasis

Nowadays, due to the rise of fast-food consumption, the metabolic diseases are increasing as a result of high-sugar and high-fat diets. Therefore, there is an urgent need for natural, healthy and side-effect-free diets in daily life. Whole grain supplementation can enhance satiety and regulate energy metabolism, effects that have been attributed to polyphenol content. Dietary polyphenols interact with gut microbiota to produce intermediate metabolites that can regulate appetite while also enhancing prebiotic effects. This review considers how interactions between gut metabolites and dietary polyphenols might regulate appetite by acting on the gut-brain axis. In addition, further advances in the study of dietary polyphenols and gut microbial metabolites on energy metabolism and gut homeostasis are summarized. This review contributes to a better understanding of how dietary polyphenols regulate appetite via the gut-brain axis, thereby providing nutritional references for citizens' dietary preferences.

The interplay of p38 MAPK signaling and mitochondrial metabolism, a dynamic target in cancer and pathological contexts

Mitochondria play a crucial role in cellular metabolism and bioenergetics, orchestrating various cellular processes, including energy production, metabolism, adaptation to stress, and redox balance. Besides, mitochondria regulate cellular metabolic homeostasis through coordination with multiple signaling pathways. Importantly, the p38 mitogen-activated protein kinase (MAPK) signaling pathway is a key player in the intricate communication with mitochondria, influencing various functions. This review explores the multifaced interaction between the mitochondria and p38 MAPK signaling and the consequent impact on metabolic alterations. Overall, the p38 MAPK pathway governs the activities of key mitochondrial proteins, which are involved in mitochondrial biogenesis, oxidative phosphorylation, thermogenesis, and iron homeostasis. Additionally, p38 MAPK contributes to the regulation of mitochondrial responses to oxidative stress and apoptosis induced by cancer therapies or natural substances by coordinating with other pathways responsible for energy homeostasis. Therefore, dysregulation of these interconnected pathways can lead to various pathologies characterized by aberrant metabolism. Consequently, gaining a deeper understanding of the interaction between mitochondria and the p38 MAPK pathway and their implications presents exciting forecasts for novel therapeutic interventions in cancer and other disorders characterized by metabolic dysregulation.

Mitophagy suppression by miquelianin-rich lotus leaf extract induces 'beiging' of white fat via AMPK/DRP1-PINK1/PARKIN signaling axis

BACKGROUND

Lotus (Nelumbo nucifera) leaf has been described to have anti-obesity activity, but the role of white fat 'browning' or 'beiging' in its beneficial metabolic actions remains unclear. Here, 3T3-L1 cells and high-fat-diet (HFD)-fed mice were used to evaluate the effects of miquelianin-rich lotus leaf extract (LLE) on white-to-beige fat conversion and its regulatory mechanisms.

RESULTS

Treatment with LLE increased mitochondrial abundance, mitochondrial membrane potential and NAD+ /NADH ratio in 3T3-L1 cells, suggesting its potential in promoting mitochondrial activity. qPCR and/or western blotting analysis confirmed that LLE induced the expression of beige fat-enriched gene signatures (e.g. Sirt1, Cidea, Dio2, Prdm16, Ucp1, Cd40, Cd137, Cited1) and mitochondrial biogenesis-related markers (e.g. Nrf1, Cox2, Cox7a, Tfam) in 3T3-L1 cells and inguinal white adipose tissue of HFD-fed mice. Furthermore, we found that LLE treatment inhibited mitochondrial fission protein DRP1 and blocked mitophagy markers such as PINK1, PARKIN, BECLIN1 and LC-3B. Chemical inhibition experiments revealed that AMPK/DRP1 signaling was required for LLE-induced beige fat formation via suppressing PINK1/PARKIN/mitophagy.

CONCLUSION

Our data reveal a novel mechanism underlying the anti-obesity effect of LLE, namely the induction of white fat beiging via AMPK/DRP1/mitophagy signaling. © 2023 Society of Chemical Industry.

Network pharmacology and experimental validation on yangjing zhongyu decoction against diminished ovarian reserve

ETHNOPHARMACOLOGICAL RELEVANCE

Diminished ovarian reserve (DOR) was considered a refractory reproductive endocrine condition that negatively affected female reproductivity. Yangjing Zhongyu Decoction (YJZYD) had effects on treating infertility. However, there were few studies on the mechanisms of YJZYD preserving ovarian reserve.

AIM OF THE STUDY

To explore the possible mechanisms of YJZYD against DOR by UPLC-ESI-MS/MS, network pharmacology, and experimental validation.

METHODS

The chemicals of YJZYD were measured by UPLC-ESI-MS/MS. The correlating targets of YJZYD and DOR were identified by the ETCM database, GeneCards database, and PubMed database. The common targets were employed with the DAVID database and visualized with the PPI network. GO and KEGG enrichment analyses were carried out to explore biological progression and pathways. In vivo experiments, energy production was assessed by ATP, and apoptosis rate was analyzed by TUNEL. The serum FSH, AMH, and E2 levels were evaluated by ELISA. Western blotting and immunohistochemistry were used to measure the expression of SIRT1, PGC1α, NRF1, COX IV, FSHR, CYP19A1, PI3K, p-Akt, Akt, Bcl-2, and Bax.

RESULTS

132 components in YJZYD were identified by UPLC-ESI-MS/MS. 149 overlapped targets were extracted from YJZYD and DOR, and the top 20 common targets included AKT1 and CYP19A1. ATP binding was involved in GO analysis. In the KEGG enrichment analysis, the metabolic pathway was the top, and the PI3K-Akt signaling pathway was included. In vivo experiments, YJZYD improved ovarian index and histomorphology. After YJZYD treatment, serum FSH, E2, and AMH were well-modulated, and the content of ATP was up-regulated. Besides, the expression of Bax was suppressed in ovarian tissue, while the expressions of SIRT1, PGC1α, NRF1, COX IV, FSHR, CYP19A1, PI3K, Bcl-2, and p-Akt/Akt were enhanced.

CONCLUSION

YJZYD could attenuate reproductive endocrine disturbance and ovarian lesions in vivo by mediating steroidogenesis, energy metabolism, and cell apoptosis. This study uncovered the mechanisms of YJZYD against DOR, providing a theoretical basis for further study.

Miquelianin in Folium Nelumbinis extract promotes white-to-beige fat conversion via blocking AMPK/DRP1/mitophagy and modulating gut microbiota in HFD-fed mice

The main purpose of the present study was to investigate the effect of miquelianin (quercetin 3-O-glucuronide, Q3G), one of the main flavonoids in the Folium Nelumbinis extract (FNE), on beige adipocyte formation and its underlying mechanisms. In 3T3-L1 adipocytes Q3G (12.8%)-rich FNE treatment upregulated beige-related markers such as SIRT1, COX2, PGC-1α, TFAM, and UCP1. Furthermore, Q3G enhanced mitochondrial biosynthesis and inhibited mitophagy by downregulating the expression of PINK1, PARKIN, BECLIN1 and LC-3B in 3T3-L1 cells. Moreover, in high-fat-diet (HFD)-fed mice, Q3G markedly inhibited body weight gain, reduced blood glucose/lipid levels, reduced white adipose tissues (WAT) and mitigated hepatic steatosis. Meanwhile, the induced beiging accompanied by suppressed mitophagy was also demonstrated in inguinal WAT (iWAT). Chemical intervention of AMPK activity with Compound C (Com C) and Acadesine (AICAR) revealed that AMPK/DRP1 signaling was involved in Q3G-mediated mitophagy and the beiging process. Importantly, 16S rRNA sequencing analysis showed that Q3G beneficially reshaped gut microbiota structure, specifically inhibiting unclassified_Lachnospiraceae, Faecalibaculum, Roseburia and Colidextribacter while increasing Bacteroides, Akkermansia and Mucispirillum, which may potentially facilitate WAT beiging. Collectively, our findings provide a novel biological function for Folium Nelumbinis and Q3G in the fight against obesity through activating the energy-dissipating capacity of beige fat.