Theabrownin Induces Cell Apoptosis and Cell Cycle Arrest of Oligodendroglioma and Astrocytoma in Different Pathways

Distinguishable short-term effects of tea and water drinking on human saliva redox

Food consumption can alter the biochemistry and redox status of human saliva, and the serving temperature of food may also play a role. The study aimed to explore the immediate (3 min) and delayed (30 min) effects of hot tea (57 ± 0.5 °C) ingestion and cold tea (8 ± 0.5 °C) ingestion on the salivary flow rate and salivary redox-relevant attributes. The saliva was collected from 20 healthy adults before, 3-min after and 30-min after the tea ingestion. The hot or cold deionised water at the same temperatures were used as control. The salivary flow rate and redox markers in hot tea (HBT), cold tea (CBT), hot water (HW) and cold water (CW) group were analysed and compared. The results demonstrated that neither the black tea nor the water altered the salivary flow rate; the black tea immediately increased the salivary thiol (SH) and malondialdehyde (MDA) content while reduced salivary uric acid (UA) significantly. The tea ingestion showed a tendency to elevate the ferric reducing antioxidant power (FRAP) in saliva, although not significantly. The water ingestion decreased the MDA content immediately and increased the UA level significantly. Cold water was found to induce a greater delayed increase in total salivary total protein (TPC) than the hot water. In conclusion, the black tea ingestion affects the redox attributes of human saliva acutely and significantly, while the temperature of drink makes the secondary contribution.

Qingzhuan dark tea Theabrownin alleviates hippocampal injury in HFD-induced obese mice through the MARK4/NLRP3 pathway

Background

Feeding on a high-fat diet (HFD) results in obesity and chronic inflammation, which may have long-term effects on neuroinflammation and hippocampal injury. Theabrownin, a biologically active compound derived from the microbial fermentation of Qingzhuan dark tea, exhibits anti-inflammatory properties and lipid-lowering effects. Nevertheless, its potential in neuroprotection has yet to be investigated. Consequently, this study aims to investigate the neuroprotective effects of Theabrownin extracted from Qingzhuan dark tea, as well as its potential therapeutic mechanisms.

Methods

Male C57 mice were subjected to an 8-week HFD to induce obesity, followed by oral administration of Theabrownin from Qingzhuan dark tea. Lipid levels were detected by Elisa kit, hippocampal morphological damage was evaluated by HE and Nissl staining, and the expression levels of GFAP, IBA1, NLRP3, MARK4, and BAX in the hippocampus were detected by immunofluorescence (IF), and protein expression levels of NLRP3, MARK4, PSD95, SYN1, SYP, and Bcl-2 were detected by Western Blot (WB).

Results

Theabrownin treatment from Qingzhuan dark tea prevents alterations in body weight and lipid levels in HFD-fed mice. Furthermore, Theabrownin decreased hippocampal morphological damage and reduced the activation of astrocytes and microglia in HFD-fed mice. Moreover, Theabrownin decreased the expression of MARK4 and NLRP3 in HFD-fed mice. Besides, Theabrownin elevated the expression of PSD95, SYN1, and SYP in HFD-fed obese mice. Finally, Theabrownin prevented neuronal apoptosis, reduced the expression of BAX, and increased the expression of Bcl-2 in HFD-fed obese mice.

Conclusions

In summary, our current study presents the first demonstration of the effective protective effect of Theabrownin from Qingzhuan dark tea against HFD-induced hippocampal damage in obese mice. This protection may result from the regulation of the MARK4/NLRP3 signaling pathway, subsequently inhibiting neuroinflammation, synaptic plasticity, and neuronal apoptosis.

Theabrownin: a dietary nutraceutical with diverse anticancer mechanisms

Cancer, a highly deadly disease, necessitates safe, cost-effective, and readily accessible treatments to mitigate its impact. Theabrownin (THBR), a polyphenolic pigment found in Pu-erh tea, has garnered attention for its potential benefits in memory, liver health, and inflammation control. By observing different biological activities of THBR, recently researchers have unveiled THBR's promising anticancer properties across various human cancer types. By examining existing studies, it is evident that THBR demonstrates substantial potential in inhibiting cell proliferation and reducing tumour size with minimal harm to normal cells. These effects are achieved through the modulation of key molecular markers such as Bcl-2, Bax, various Caspases, Poly (ADP-ribose) polymerase cleavage (Cl-PARP), and zinc finger E box binding homeobox 1 (ZEB 1). This review aims to provide in-depth insights into THBR's role in cancer research. This review also elucidates the underlying anticancer mechanisms of THBR, offering promise as a novel anticancer drug to alleviate the global cancer burden.

Physicochemical stability and antibacterial mechanism of theabrownins prepared from tea polyphenols catalyzed by polyphenol oxidase and peroxidase

Tea polyphenols were used as substrates and oxidized successively by polyphenol oxidase and peroxidase to prepare theabrownins (TBs-dE). The conversion rate of catechins to TBs-dE was 90.91%. The ultraviolet and infrared spectroscopic properties and zeta potential of TBs-dE were characterized. TBs-dE is more stable at pH 5.0-7.0, about 25 °C or in dark environment. Ultraviolet light and sunlight can deepen its color due to the further oxidative polymerization. Mg2+, Cu2+, and Al3+ had a significant effect on the stability of TBs-dE. The inhibitory rates of TBs-dE (1 mg/mL) against Staphylococcus aureus and Escherichia coli DH5α were 51.45% and 45.05%, respectively. After TBs-dE treatment, the cell morphology of both bacteria changed, some cell walls were blurred, and the cytoplasmic content leaked. The research results can provide theoretical support for the industrialization of theabrownins.

Diosbulbin C, a novel active ingredient in Dioscorea bulbifera L. extract, inhibits lung cancer cell proliferation by inducing G0/G1 phase cell cycle arrest

BACKGROUND

Despite the critical progress of non-small cell lung cancer (NSCLC) therapeutic approaches, the clinical outcomes remain considerably poor. The requirement of developing novel therapeutic interventions is still urgent. In this study, we showed for the first time that diosbulbin C, a natural diterpene lactone component extracted from traditional Chinese medicine Dioscorea bulbifera L., possesses high anticancer activity in NSCLC.

METHODS

A549 and NCI-H1299 cells were used. The inhibitory effects of the diosbulbin C on NSCLC cell proliferation were evaluated using cytotoxicity, clone formation, EdU assay, and flow cytometry. Network pharmacology methods were used to explore the targets through which the diosbulbin C inhibited NSCLC cell proliferation. Molecular docking, qRT-PCR, and western blotting were used to validate the molecular targets and regulated molecules of diosbulbin C in NSCLC.

RESULTS

Diosbulbin C treatment in NSCLC cells results in a remarkable reduction in cell proliferation and induces significant G0/G1 phase cell cycle arrest. AKT1, DHFR, and TYMS were identified as the potential targets of diosbulbin C. Diosbulbin C may inhibit NSCLC cell proliferation by downregulating the expression/activation of AKT, DHFR, and TYMS. In addition, diosbulbin C was predicted to exhibit high drug-likeness properties with good water solubility and intestinal absorption, highlighting its potential value in the discovery and development of anti-lung cancer drugs.

CONCLUSIONS

Diosbulbin C induces cell cycle arrest and inhibits the proliferation of NSCLC cells, possibly by downregulating the expression/activation of AKT, DHFR, and TYMS.

Theabrownin Isolated from Pu-Erh Tea Enhances the Innate Immune and Anti-Inflammatory Effects of RAW264.7 Macrophages via the TLR2/4-Mediated Signaling Pathway

Theabrownin (TB) is a tea pigment extracted from Pu-erh Tea. The effects of TB on innate immunity and inflammation are not well understood. Herein, the effects of TB on innate immunity are investigated using RAW264.7 macrophages. We found that TB promoted the proliferation of RAW264.7 macrophages, altered their morphology, enhanced their pinocytic and phagocytic ability, and significantly increased their secretion of nitric oxide (NO) and cytokines, all of which enhanced the immune response. Additionally, TB inhibited the release of inflammatory signals in RAW264.7 macrophages primed with lipopolysaccharide (LPS), implying that TB modulates the excessive inflammation induced by bacterial infection. A Western blot showed that TB could activate the toll-like receptor (TLR)2/4-mediated myeloid differentiation factor 88 (MyD88)-dependent mitogen activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) signaling pathway and the TLR2-mediated phosphoinositide 3-kinase (PI3K)-AKT signaling pathway, enhancing the immune functions of RAW264.7 macrophages. TB also inhibited the phosphorylation of core proteins in the MAPK/NF-κB/PI3K-AKT signaling pathway induced by LPS. In addition, we analyzed the transcriptomes of RAW264.7 macrophages, and a Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis revealed that TB modulated thetoll-like receptor signal pathway. A gene ontology (GO) enrichment analysis indicated that TB treatment strongly modulated the immune response and inflammation. As a result, TB-enhanced innate immunity and modulated inflammation via the TLR2/4 signaling pathway.

Theabrownin Alleviates Colorectal Tumorigenesis in Murine AOM/DSS Model via PI3K/Akt/mTOR Pathway Suppression and Gut Microbiota Modulation

Colorectal cancer (CRC) is one of the most common and fatal cancers worldwide, yet therapeutic options for CRC often exhibit strong side effects which cause patients’ well-being to deteriorate. Theabrownin (TB), an antioxidant from Pu-erh tea, has previously been reported to have antitumor effects on non-small-cell lung cancer, osteosarcoma, hepatocellular carcinoma, gliomas, and melanoma. However, the potential antitumor effect of TB on CRC has not previously been investigated in vivo. The present study therefore aimed to investigate the antitumor effect of TB on CRC and the underlying mechanisms. Azoxymethane (AOM)/dextran sodium sulphate (DSS) was used to establish CRC tumorigenesis in a wild type mice model. TB was found to significantly reduce the total tumor count and improve crypt length and fibrosis of the colon when compared to the AOM/DSS group. Immunohistochemistry staining shows that the expression of the proliferation marker, Ki67 was reduced, while cleaved caspase 3 was increased in the TB group. Furthermore, TB significantly reduced phosphorylation of phosphatidylinositol 3-kinase (PI3K), protein kinase B (Akt), and the downstream mechanistic target of rapamycin (mTOR)and cyclin D1 protein expression, which might contribute to cell proliferation suppression and apoptosis enhancement. The 16s rRNA sequencing revealed that TB significantly modulated the gut microbiota composition in AOM/DSS mice. TB increased the abundance of short chain fatty acid as well as SCFA-producing Prevotellaceae and Alloprevotella, and it decreased CRC-related Bacteroidceae and Bacteroides. Taken together, our results suggest that TB could inhibit tumor formation and potentially be a promising candidate for CRC treatment.

Theabrownins Produced via Chemical Oxidation of Tea Polyphenols Inhibit Human Lung Cancer Cells in vivo and in vitro by Suppressing the PI3K/AKT/mTOR Pathway Activation and Promoting Autophagy

During the fermentation of dark tea, theabrownins (TBs), carbohydrates, and other substances get irreversibly complex. Recent research on the biological activity of TBs is not based on free TBs. In the present study, some brown polyphenol oxidized polymers, the generalized TBs (TBs-C), were prepared via alkali oxidation from tea polyphenols (TP). We also investigated the inhibitory mechanism of TBs-C on non-small-cell-lung cancer (NSCLC). TBs-C demonstrated a stronger inhibition than TP on the NSCLC cell lines A549, H2030, HCC827, H1975, and PC9. Next, A549 and H2030 cell lines were selected as subjects to explore this mechanism. TBs-C was found to inhibit proliferation, promote apoptosis, and induce G1 cell-cycle arrest in the cells. In addition, TBs-C increased autophagic flux, which in turn promoted the death of lung cancer cells. Moreover, TBs-C suppressed the PI3K/AKT/mTOR pathway activation, promoted autophagy, and increased the expression of p21 downstream of AKT, which resulted in G1 cell-cycle arrest. In xenotransplanted NSCLC nude mice derived from A549 cells, TBs-C could significantly suppress tumor growth by inhibiting the PI3K/AKT/mTOR pathway without causing hepatotoxicity, brain toxicity, or nephrotoxicity. We believe that our present findings would facilitate advancement in the research and industrialization of TBs.

Molecular Mechanism of Chrysin in Hepatocellular Carcinoma Treatment Based on Network Pharmacology and in Vitro Experiments

This study elucidated the potential molecular mechanism of chrysin in hepatocellular carcinoma (HCC) treatment using network pharmacology and in vitro experiments. Chrysin and candidate targets of HCC were obtained from the TCMSP and DrugBank databases, followed by mapping and screening of chrysin and HCC targets to identify the core targets of chrysin in HCC treatment. The interaction of chrysin and its targets, including CDK1, CDK5, as well as MMP9, were evaluated by molecular docking. The STRING database and Cytoscape (version 3.8.2) software were used to construct protein interactions and component-target networks of the core targets. Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathway enrichment analysis of the core target genes were performed using the DAVID database. Network pharmacology results showed that chrysin treatment of HCC was mainly related to cell proliferation and cell cycle. Accordingly, the cell counting kit-8 method and flow cytometry were used to detect the cell viability and cell cycle of hepatocarcinoma cells HCCLM3 and BEL-7402 in vitro. A total of 142 compound targets of chrysin, 12,179 HCC-related targets, and 116 intersecting targets were screened. The first 20 GO biological annotations of 17 core targets and the first 20 KEGG pathways mainly involved cell proliferation and cell cycle. In vitro experiments showed that chrysin inhibits the proliferation of human hepatocarcinoma cells (HCCLM3 and BEL-7402) in a dose-dependent manner. Moreover, chrysin induced cell cycle arrest in HCCLM3 and BEL-7402 cells in the G2 phase, and the expression was downregulated of cyclin-dependent kinases (CDKs), CDK2 and CDK4. Chrysin can offset HCC mainly by regulating the cell cycle and inhibiting cell proliferation. The network pharmacology results were verified, providing the basis for further study on the mechanism of chrysin intervention in HCC.

Differential Regulation of the EGFR/PI3K/AKT/PTEN Pathway between Low- and High-Grade Gliomas

Gliomas represent 70% of all central system nervous tumors and are classified according to the degree of malignancy as low- or high-grade. The permanent activation of the EGFR/PI3K/AKT pathway by various genetic or post-translational alterations of EGFR, PI3KCA, and PTEN has been associated with increased proliferation and resistance to apoptosis. The present study aimed to analyze the molecular/genetic changes in the EGFR/PI3K/AKT/PTEN pathway between low-grade and high-grade gliomas in a sample of Colombian patients. A total of 30 samples were tested for PI3K and PTEN mutations, EGFR, PI3K, and AKT gene amplification, AKT, PI3K, BAX, Bcl2 expression levels, and phosphorylation of AKT and PTEN, EGFR and/or PI3K gene amplification was found in 50% of low-grade and 45% of high-grade ones. AKT amplification was found in 25% of the low-grade and 13.6% of the high-grade. The expression of PI3K, AKT, Bcl2, and BAX was increased particularly to a high degree. AKT phosphorylation was found in 66% of low-grade and 31.8% of high-grade. Increased phosphorylation of PTEN was found in 77% low-grade and 66% high-grade. Our results indicate that alterations in the EGFR/PI3K/AKT/PTEN pathway could be important in the initiation and malignant progression of this type of tumor.