Quercetin counteracts monosodium glutamate to mitigate immunosuppression in the thymus and spleen via redox-guided cellular signaling

Guizhi Fuling Wan attenuates tetrachloromethane-induced hepatic fibrosis in rats via PTEN/AKT/mTOR signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Treatment options for hepatic fibrosis, a prevalent liver condition closely linked to cirrhosis, are currently limited. While Guizhi Fuling Wan (GFW), a pill derived from traditional Chinese herbs, has been reported to possess hepatoprotective properties, its therapeutic effect and mechanism in hepatic fibrosis remain elusive.

AIM OF THE STUDY

This study aimed to evaluate the anti-fibrotic impact of GFW and its underlying mechanisms in both in vivo and in vitro settings.

MATERIALS AND METHODS

Tetrachloromethane (CCl4) was used to induce hepatic fibrosis in male rats. In vitro, activation of hepatic stellate cells (HSCs) was triggered by platelet-derived growth factor-BB (PDGF-BB). In vivo, liver function, pathological alterations, and HSC activation were evaluated. Additionally, the impact of GFW on the activated phenotypes of Lieming Xu-2 (LX-2) cells was examined in vitro. Network pharmacology was employed to identify the potential targets of GFW in hepatic fibrosis. Lastly, the impact of GFW on the PTEN/AKT/mTOR pathway and PTEN ubiquitination in HSCs was investigated.

RESULTS

GFW alleviated CCl4-induced liver damage and scarring in rats in a dose-dependent manner and suppressed HSC activation in vivo. Moreover, GFW inhibited the proliferation, migration, differentiation, and extracellular matrix (ECM) production of activated HSCs in vitro. GFW also promoted autophagy and apoptosis of HSCs. Meanwhile, network pharmacology and in vitro studies suggested that GFW inhibits the AKT/mTOR pathway by preventing PTEN degradation by suppressing ubiquitination.

CONCLUSION

GFW attenuates Ccl4-induced hepatic fibrosis in male rats by regulating the PTEN/AKT/mTOR signaling pathway, positioning it as a potential candidate for the treatment of hepatic fibrosis.

Tao-Hong-Si-Wu-Tang improves thioacetamide-induced liver fibrosis by reversing ACSL4-mediated lipid accumulation and promoting mitophagy

ETHNOPHARMACOLOGICAL RELEVANCE

Liver fibrosis is a generic fibrous scarring event resulting from accumulation of extracellular matrix (ECM) proteins, easily progressing to end-stage liver diseases. Tao-Hong-Si-Wu-Tang (THSWT) is a traditional Chinese medicine formula applied in clinics to treat gynecological and chronic liver diseases. However, the role of THSWT on thioacetamide (TAA)-induced hepatic fibrosis and the specific mechanisms remains unclear.

AIM OF THE STUDY

To investigate the improving effects of THSWT on TAA-insulted hepatic fibrosis and the underlying mechanisms.

MATERIALS AND METHODS

UHPLC-MS/MS was performed to explore the chemical characterization of THSWT. Mice were orally administered with THSWT once daily for 6 weeks along with TAA challenge. Liver function was reflected through serum biomarkers and histopathological staining. RNA sequencing, non-targeted metabolomics and molecular biology experiments were applied to investigate the underlying mechanisms.

RESULTS

THSWT profoundly repaired lipid metabolism dysfunction and blocked collagen accumulation both in TAA-stimulated mice and in hepatocytes. Results of RNA sequencing and non-targeted metabolomics revealed that the anti-fibrotic effects of THSWT mostly relied on lipid metabolism repairment by increasing levels of acetyl-CoA, phosphatidylcholine, phosphatidylethanolamine, lysophosphatidylcholine and lysophosphatidylethanolamine, and decreasing relative abundances of acyl-CoA, total cholesterol, diacylglycerol, triacylglycerol and phosphatidylinositol. Mechanically, long-chain acyl-CoA synthetases 4 (ACSL4) was a key profibrotic target both in human and mice by disrupting lipid oxidation and metabolism in hepatic mitochondria. THSWT effectively blocked ACSL4 and promoted mitophagy to reverse above outcomes, which was verified by mitophagy depletion.

CONCLUSION

THSWT may be a promising therapeutic option for treating hepatic fibrosis and its complications by modulating lipid metabolism and promoting mitophagy in livers.

Quercetin-primed BMSC-derived extracellular vesicles ameliorate chronic liver damage through miR-136-5p and GNAS/STAT3 signaling pathways

BACKGROUND

Chronic liver damage (CLD) is a long-term and progressive liver condition characterized by inflammation, fibrosis, and impaired liver function, which ultimately lead to severe complications such as cirrhosis or liver cancer. Quercetin (Que), a flavonoid in various plants, possesses anti-inflammatory, antiviral, anti-ischemic, and anticancer properties. Recently, extracellular vesicles (EVs) derived from pretreated bone marrow mesenchymal stem cells (BMSCs) have shown immense potential in treating various diseases, including CLD. Thus, this study evaluated the regulatory effects of Que-preconditioned BMSC-derived EVs (Que-EVs) on LPS-stimulated RAW264.7 cells and their therapeutic effects on mice with CLD.

METHODS

Que-EVs and control-EVs were harvested from the cell culture supernatant of BMSCs. The EVs were characterized using western blot, transmission electron microscopy, and nanoparticle tracking analysis. Further, the DIR labeling of EVs was used to detect in vitro and in vivo uptake. Next, LPS pre-stimulated RAW264.7 cells were treated with Que-EVs and control-EVs for 24 h. The relative expression of inflammatory cytokines and macrophage polarization markers genes was assessed using RT-qPCR, and western blot was conducted to evaluate the GNAS, PI3K, ERK, and STAT3 gene and protein expressions in RAW264.7 cells. Furthermore, transfection techniques were employed to induce miR-136-5p inhibition and GNAS overexpression in RAW264.7 cells to validate the role of miR-136-5p in alleviating inflammation through the GNAS/PI3K/ERK/STAT3 pathway. Subsequently, the outcomes were validated via in vitro experiments.

RESULTS

Que enhanced miR-136-5p expression in BMSC-EVs. Furthermore, it was shown that EVs delivered miR-136-5p to macrophages, thereby attenuating M1-type macrophage polarisation through the GNAS/PI3K/ERK/STAT3 pathway, reducing liver inflammation, improving liver function and treating CLD.

Quercetin inhibits NF-kB and JAK/STAT signaling via modulating TLR in thymocytes and splenocytes during MSG-induced immunotoxicity: an in vitro approach

BACKGROUND

The most widely used food additive monosodium glutamate (MSG) has been linked to immunopathology. Conversely, quercetin (Q), a naturally occurring flavonoid has been demonstrated to have immunomodulatory functions. Therefore, the purpose of the study is to determine if quercetin can mitigate the deleterious effects of MSG on immune cells, and the possible involvement of TLR, if any.  METHODS AND RESULTS: This study was conducted on Q, to determine how it affects the inflammatory response triggered by MSG in primary cultured thymocytes and splenocytes from rats (n = 5). Q shielded cells by augmenting cell survival and decreasing lactate dehydrogenase leakage during MSG treatment. It decreased IL-1β, IL-6, IL-8, and TNF-α expression and release by hindering NF-kB activation and by inhibiting the JAK/STAT pathway. Moreover, Q prevented NLRP3 activation, lowered IL-1β production, and promoted an anti-inflammatory response by increasing IL-10 production. Q reduced MSG-induced cellular stress and inflammation by acting as an agonist for PPAR-γ and LXRα, preventing NF-kB activation, and lowering MMP-9 production via increasing TIMP-1. Additionally, Q neutralized free radicals, elevated intracellular antioxidants, and impeded RIPK3, which is involved in inflammation induced by oxidative stress, TNF-α, and TLR agonists in MSG-treated cells. Furthermore, it also modulated TYK2 and the JAK/STAT pathway, which exhibited an anti-inflammatory effect.

CONCLUSIONS

MSG exposure is associated with immune cell dysfunction, inflammation, and oxidative stress, and Q modulates TLR to inhibit NF-kB and JAK/STAT pathways, providing therapeutic potential. Further research is warranted to understand Q's downstream effects and explore its potential clinical applications in inflammation.