Theabrownin from Dark Tea Ameliorates Insulin Resistance via Attenuating Oxidative Stress and Modulating IRS-1/PI3K/Akt Pathway in HepG2 Cells

Cynomorium songaricum: UHPLC/ESI-LTQ-Orbitrap-MS analysis and mechanistic study on insulin sensitivity of a flavonoid-enriched fraction

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder characterized by elevated blood glucose levels, posing a significant global health concern due to its increasing prevalence. Insulin resistance (IR) plays a major role in the development of T2DM and is often linked to factors such as obesity, physical inactivity, and a sedentary lifestyle. Recently, there has been growing interest in exploring the potential of natural products for improving insulin sensitivity and glucose metabolism. Among these, Cynomorium songaricum Rupr., an edible parasitic plant, has shown promising antidiabetic effects. However, research on its beneficial effects on IR is still nascent. Therefore, this study aims to investigate the application of a Cynomorium songaricum flavonoid-enriched fraction (CSF) in the treatment of IR in T2DM, along with elucidating the chemical and biochemical mechanisms involved.

METHOD

First, UHPLC/ESI-LTQ-Orbitrap-MS was utilized to perform a chemical profiling of CSF. Subsequently, glycogen synthesis, gluconeogenesis and glucose consumption assays were conducted on HepG2 cells with a high glucose high insulin-induced IR model to illustrate the favorable impacts of CSF on IR. Then, an innovative network pharmacology analysis was executed to predict the potential chemical components and hub genes contributing to CSF's protective effect against IR. To further elucidate molecular interactions, molecular docking studies were performed, focusing on the binding interactions between active constituents of CSF and crucial targets. Additionally, an RNA-sequencing assay was employed to uncover the underlying biochemical signaling pathway responsible for CSF's beneficial effects. To validate these findings, western blot and qPCR assays were employed to verify the pathways related to IR and the potential signaling cascades leading to the amelioration of IR.

RESULTS

The UHPLC/ESI-LTQ-Orbitrap-MS analysis successfully identified a total of thirty-six flavonoids derived from CSF. Moreover, CSF was shown to significantly improve glycogen synthesis and glucose consumption as well as inhibit gluconeogenesis in HepG2 cells of IR. An innovative network pharmacology analysis unveiled key hub genes-AKT1 and PI3K-integral to metabolic syndrome-related signaling pathways, which contributed to the favorable impact of CSF against IR. Noteworthy active ingredients including quercetin, ellagic acid and naringenin were identified as potential contributors to these effects. The results of western blot and qPCR assays provided compelling evidence that CSF improved insulin sensitivity by modulating the PI3K-Akt signaling pathway. Subsequent RNA-sequencing analysis, in tandem with western blot assays, delved deeper into the potential mechanisms underlying CSF's advantageous effects against IR, potentially associated with the enhancement of endoplasmic reticulum (ER) proteostasis.

CONCLUSION

CSF exhibited a remarkable ability to enhance insulin sensitivity in the IR model of HepG2 cells. This was evident through enhancements in glycogen synthesis and glucose consumption, along with its inhibitory impact on gluconeogenesis. Furthermore, CSF demonstrated an improvement in the insulin-mediated PI3K-Akt signaling pathway. The potential active constituents were identified as quercetin, ellagic acid and naringenin. The underlying biochemical mechanisms responsible for CSF's beneficial effects against IR were closely linked to its capacity to mitigate ER stress, thereby offering a comprehensive understanding of its protective action.

Modulation of Gut Microbial Biomarkers and Metabolites in Cancer Management by Tea Compounds

Cancers are causing millions of deaths and leaving a huge clinical and economic burden. High costs of cancer drugs are limiting their access to the growing number of cancer cases. The development of more affordable alternative therapy could reach more patients. As gut microbiota plays a significant role in the development and treatment of cancer, microbiome-targeted therapy has gained more attention in recent years. Dietary and natural compounds can modulate gut microbiota composition while providing broader and more accessible access to medicine. Tea compounds have been shown to have anti-cancer properties as well as modulate the gut microbiota and their related metabolites. However, there is no comprehensive review that focuses on the gut modulatory effects of tea compounds and their impact on reshaping the metabolic profiles, particularly in cancer models. In this review, the effects of different tea compounds on gut microbiota in cancer settings are discussed. Furthermore, the relationship between these modulated bacteria and their related metabolites, along with the mechanisms of how these changes led to cancer intervention are summarized.

'Nine Steaming Nine Sun-drying' processing enhanced properties of Polygonatum kingianum against inflammation, oxidative stress and hyperglycemia

BACKGROUND

Polygonatum kingianum Coll. & Hemsl (PK), a prominent medicine and food homology plant, has been consumed as a decoction from boiling water for thousands of years. 'Nine Steaming Nine Sun-drying' processing has been considered an effective method for enriching tonic properties, but studies investigating such impacts on PK and underlying mechanisms are extremely rare.

RESULTS

We first demonstrated substantial improvements in the anti-oxidative, anti-inflammatory and anti-hyperglycemia effects of the Nine Steaming Nine Sun-drying processed PK water extracts compared with crude PK in cell models (i.e., HepG2 and Raw 264.7 cells). We then integrated foodomics and network pharmacology analysis to uncover the key compounds responsible for the improved benefits. A total of 551 metabolites of PK extracts were identified, including polyphenols, flavonoids, alkaloids, and organic acids. During processing, 204 metabolites were enhanced, and 32 metabolites were recognized as key constituents of processed PK responsible for the improved health-promoting activities, which may affect PI3K-Akt-, MAPK-, and HIF-1 pathways. We further confirmed the high affinity between identified key constituents of processed PK and their predicted acting targets using molecular docking.

CONCLUSION

Our results provide novel insights into bioactive compounds of processed PK, elaborating the rationality of processing from the perspective of tonic effects. Consuming processed PK could be an efficacious strategy to combat the high prevalence of metabolic diseases that currently affect millions of people worldwide. © 2023 Society of Chemical Industry.