Schisandrin B Attenuates Hepatic Stellate Cell Activation and Promotes Apoptosis to Protect against Liver Fibrosis

Network pharmacology and transcriptomic profiling elucidate the therapeutic effects of Ranunculus ternatus Thunb on liver fibrosis via MK3-NF-κB inhibition

Activation of hepatic stellate cells (HSCs) is critical in the progression of liver fibrosis and is a promising target for anti-hepatic fibrosis drug development. Moreover, effective pharmacological interventions targeting this pathomechanism are scarce. Our study confirms the therapeutic value of β-sitosterol, a major constituent of Ranunculus ternatus Thunb, in hepatic fibrosis and identifies its underlying mechanisms. After treatment with β-sitosterol, CCL4-induced hepatic fibrosis was reversed in mice, while inflammatory and hepatic fibrosis indices were improved. Meanwhile, we explored the molecular mechanism of β-sitosterol treatment for hepatic fibrosis and, based on RNA-seq results, found that the ameliorative effect of β-sitosterol on hepatic fibrosis was associated with the MK3 and NF-κB signalling pathways. MK3, an important kinase in the MAPK pathway, plays a role in transmitting upstream and downstream signals, whereas the NF-κB signalling pathway has been shown to be associated with HSC activation. We verified the interaction between MK3 and IκB in HSC cells using endogenous Co-IP, whereas β-sitosterol reduced the binding of MK3 to IκB and the activation of the NF-κB signalling pathway. Our findings reveal the mechanism of β-sitosterol in the treatment of liver fibrosis, suggesting that β-sitosterol may be a promising drug for the treatment of liver fibrosis and deserves further investigation.

Water extract of earthworms mitigates mouse liver fibrosis by potentiating hepatic LKB1/Nrf2 axis to inhibit HSC activation and hepatocyte death

ETHNOPHARMACOLOGICAL RELEVANCE

When left untreated, liver fibrosis (LF) causes various chronic liver diseases. Earthworms (Pheretima aspergillum) are widely used in traditional medicine because of their capacity to relieve hepatic diseases.

AIM OF THE STUDY

This study aimed to explore the anti-LF effects of water extract of earthworms (WEE) and the underlying molecular mechanisms.

MATERIALS AND METHODS

A CCl4-induced mouse model of LF was used to study the impact of WEE on LF in vivo. The anti-LF activity of WEE in mice was compared with that of silybin, which can be clinically applied in LF intervention and was used as a positive control. Activation of LX-2 hepatic stellate cells (HSCs) and apoptosis and ferroptosis of AML-12 hepatocytes induced by TGFβ1 were used as in vitro models.

RESULTS

WEE drastically improved LF in mice. WEE reduced markers of activated HSCs in mice and inhibited TGFβ1-induced activation of LX-2 HSCs in vitro. Additionally, WEE suppressed CCl4-induced apoptosis and ferroptosis in mouse hepatocytes. Mechanistically, WEE induced Nrf2 to enter the nuclei of the mouse liver cells, and the hepatic levels of Nrf2-downstream antioxidative factors increased. LKB1/AMPK/GSK3β is an upstream regulatory cascade of Nrf2. In the LF mouse model, WEE increased hepatic phosphorylated LKB1, AMPK, and GSK3β levels. Similar results were obtained for the LX-2 cells. In AML-12 hepatocytes and LX-2 HSCs, WEE elevated intracellular Nrf2 levels, promoted its nuclear translocation, and inhibited TGFβ1-induced ROS accumulation. Knocking down LKB1 abolished the impact of WEE on the AMPK/GSK3β/Nrf2 cascade and eliminated its protective effects against TGFβ1.

CONCLUSIONS

Our findings reveal that WEE improves mouse LF triggered by CCl4 and supports its application as a promising hepatoprotective agent against LF. The potentiation of the hepatic antioxidative AMPK/GSK3β/Nrf2 cascade by activating LKB1 and the subsequent suppression of HSC activation and hepatocyte apoptosis and ferroptosis are implicated in WEE-mediated alleviation of LF.

Small-molecule natural plants for reversing liver fibrosis based on modulation of hepatic stellate cells activation: An update

BACKGROUND

Liver fibrosis (LF) is a trauma repair process carried out by the liver in response to various acute and chronic liver injuries. Its primary pathological characteristics are excessive proliferation and improper dismissal of the extracellular matrix, and if left untreated, it will progress into cirrhosis, liver cancer, and other diseases. Hepatic stellate cells (HSCs) activation is intimately associated to the onset of LF, and it is anticipated that addressing HSCs proliferation can reverse LF. Plant-based small-molecule medications have anti-LF properties, and their mechanisms of action involve suppression of extracellular matrix abnormally accumulating as well as anti-inflammation and anti-oxidative stress. New targeting HSC agents will therefore be needed to provide a potential curative response.

PURPOSE

The most recent HSC routes and small molecule natural plants that target HSC described domestically and internationally in recent years were examined in this review.

METHODS

The data was looked up using resources including ScienceDirect, CNKI, Web of Science, and PubMed. Keyword searches for information on hepatic stellate cells included "liver fibrosis", "natural plant", "hepatic stellate cells", "adverse reaction", "toxicity", etc. RESULTS: We discovered that plant monomers can target and control various pathways to prevent the activation and proliferation of HSC and promote the apoptosis of HSC in order to achieve the anti-LF effect in this work by compiling the plant monomers that influence many common pathways of HSC in recent years. It demonstrates the wide-ranging potential of plant monomers targeting different routes to combat LF, with a view to supplying new concepts and new strategies for natural plant therapy of LF as well as research and development of novel pharmaceuticals. The investigation of kaempferol, physalin B, and other plant monomers additionally motivated researchers to focus on the structure-activity link between the main chemicals and LF.

CONCLUSION

The creation of novel pharmaceuticals can benefit greatly from the use of natural components. They are often harmless for people, non-target creatures, and the environment because they are found in nature, and they can be employed as the starting chemicals for the creation of novel medications. Natural plants are valuable resources for creating new medications with fresh action targets because they feature original and distinctive action mechanisms.

Ganoderma lucidum polysaccharide inhibits HSC activation and liver fibrosis via targeting inflammation, apoptosis, cell cycle, and ECM-receptor interaction mediated by TGF-β/Smad signaling

BACKGROUND

Ganoderma lucidum polysaccharide (GLP) has many biological properties, however, the anti-fibrosis effect of GLP is unknown at present.

PURPOSE

This study aimed to examine the anti-fibrogenic effect of GLP and its underlying molecular mechanisms in vivo and in vitro.

STUDY DESIGN

Both CCl₄-induced mouse and TGF-β1-induced HSC-T6 cellular models of fibrosis were established to examine the anti-fibrogenic effect of a water-soluble GLP (25 kDa) extracted from the sporoderm-removed spores of G. lucidum..

METHOD

Serum markers of liver injury, histology and fibrosis of liver tissues, and collagen formation were examined using an automatic biochemical analyzer, H&E staining, Sirius red staining, immunohistochemistry, immunofluorescence, ELISA, Western blotting, and qRT-PCR. RNA-sequencing, enrichment pathway analysis, Western blotting, qRT-PCR, and flow cytometry were employed to identify the potential molecular targets and signaling pathways that are responsible for the anti-fibrotic effect of GLP.

RESULTS

We showed that GLP (150 and 300 mg/kg) significantly inhibited hepatic fibrogenesis and inflammation in CCl₄-treated mice as mediated by the TLR4/NF-κB/MyD88 signaling pathway. We further demonstrated that GLP significantly inhibited hepatic stellate cell (HSCs) activation in mice and in TGF-β1-induced HSC-T6 cells as manifested by reduced collagen I and a-SMA expressions. RNA-sequencing uncovered inflammation, apoptosis, cell cycle, ECM-receptor interaction, TLR4/NF-κB, and TGF-β/Smad signalings as major pathways suppressed by GLP administration. Further studies demonstrated that GLP elicits anti-fibrotic actions that are associated with a novel dual effect on apoptosis in vivo (inhibit) or in vitro (promote), suppression of cell cycle in vivo, induction of S phase arrest in vitro, and attenuation of ECM-receptor interaction-associated molecule expressions including integrins ITGA6 and ITGA8. Furthermore, GLP significantly inhibited the TGF-β/Smad signaling in mice, and reduced TGF-β1 or its agonist SRI-011381-induced Smad2 and Smad3 phosphorylations, but increased Samd7 expression in HSC-T6 cells.

CONCLUSION

This study provides the first evidence that GLP could be a promising dietary strategy for treating liver fibrosis, which protects against liver fibrosis and HSC activation through targeting inflammation, apoptosis, cell cycle, and ECM-receptor interactions that are mediated by TGF-β/Smad signaling.

A Comparison of the Gene Expression Profiles of Non-Alcoholic Fatty Liver Disease between Animal Models of a High-Fat Diet and Methionine-Choline-Deficient Diet

Non-alcoholic fatty liver disease (NAFLD) embraces several forms of liver disorders involving fat disposition in hepatocytes ranging from simple steatosis to the severe stage, namely, non-alcoholic steatohepatitis (NASH). Recently, several experimental in vivo animal models for NAFLD/NASH have been established. However, no reproducible experimental animal model displays the full spectrum of pathophysiological, histological, molecular, and clinical features associated with human NAFLD/NASH progression. Although methionine-choline-deficient (MCD) diet and high-fat diet (HFD) models can mimic histological and metabolic abnormalities of human disease, respectively, the molecular signaling pathways are extremely important for understanding the pathogenesis of the disease. This review aimed to assess the differences in gene expression patterns and NAFLD/NASH progression pathways among the most common dietary animal models, i.e., HFD- and MCD diet-fed animals. Studies showed that the HFD and MCD diet could induce either up- or downregulation of the expression of genes and proteins that are involved in lipid metabolism, inflammation, oxidative stress, and fibrogenesis pathways. Interestingly, the MCD diet model could spontaneously develop liver fibrosis within two to four weeks and has significant effects on the expression of genes that encode proteins and enzymes involved in the liver fibrogenesis pathway. However, such effects in the HFD model were found to occur after 24 weeks with insulin resistance but appear to cause less severe fibrosis. In conclusion, assessing the abnormal gene expression patterns caused by different diet types provides valuable information regarding the molecular mechanisms of NAFLD/NASH and predicts the clinical progression of the disease. However, expression profiling studies concerning genetic variants involved in the development and progression of NAFLD/NASH should be conducted.

The Antioxidant Phytochemical Schisandrin A Promotes Neural Cell Proliferation and Differentiation after Ischemic Brain Injury

Schisandrin A (SCH) is a natural bioactive phytonutrient that belongs to the lignan derivatives found in Schisandra chinensis fruit. This study aims to investigate the impact of SCH on promoting neural progenitor cell (NPC) regeneration for avoiding stroke ischemic injury. The promoting effect of SCH on NPCs was evaluated by photothrombotic model, immunofluorescence, cell line culture of NPCs, and Western blot assay. The results showed that neuron-specific class III beta-tubulin (Tuj1) was positive with Map2 positive nerve fibers in the ischemic area after using SCH. In addition, Nestin and SOX2 positive NPCs were significantly (p < 0.05) increased in the penumbra and core. Further analysis identified that SCH can regulate the expression level of cell division control protein 42 (Cdc42). In conclusion, our findings suggest that SCH enhanced NPCs proliferation and differentiation possible by Cdc42 to regulated cytoskeletal rearrangement and polarization of cells, which provides new hope for the late recovery of stroke.