Curcumin reduces methionine adenosyltransferase 2B expression by interrupting phosphorylation of p38 MAPK in hepatic stellate cells

Defining the mechanisms behind the hepatoprotective properties of curcumin

As a critical cause of human dysfunctionality, hepatic failure leads to approximately two million deaths per year and is on the rise. Considering multiple inflammatory, oxidative, and apoptotic mechanisms behind hepatotoxicity, it urges the need for finding novel multi-targeting agents. Curcumin is a phenolic compound with anti-inflammatory, antioxidant, and anti-apoptotic roles. Curcumin possesses auspicious health benefits and protects against several diseases with exceptional safety and tolerability. This review focused on the hepatoprotective mechanisms of curcumin. The need to develop novel delivery systems of curcumin (e.g., nanoparticles, self-micro emulsifying, lipid-based colloids, solid lipid nanoparticles, cyclodextrin inclusion, phospholipid complexes, and nanoemulsions) is also considered.

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.

Integration of transcriptomics and metabonomics revealed the protective effects of hemp seed oil against methionine-choline-deficient diet-induced non-alcoholic steatohepatitis in mice

Non-alcoholic steatohepatitis (NASH) is a chronic liver disease with few therapeutic options available currently. Hemp seed oil extracted from the seeds of hemp (Cannabis sativa L.) has significant nutritional and biological properties due to the unique composition of polyunsaturated fatty acids and various antioxidant compounds. However, little is known about the beneficial effects and molecular mechanisms of hemp seed oil on NASH. Here, the hepatoprotective effects of hemp seed oil on methionine-choline-deficient (MCD) diet-induced NASH in C57BL/6 mice were explored via integration of transcriptomics and metabolomics. Hemp seed oil could improve hepatic steatosis, inflammation and fibrosis in mice with MCD diet-induced NASH. In a nuclear magnetic resonance (NMR)-based metabonomic study, the hepatic and urinary metabolic profiles of mice supplemented with hemp seed oil showed a tendency to recover to healthy controls compared to those of NASH mice. Eight potential biomarkers associated with NASH in both liver tissue and urine were restored to near normal levels by administration of hemp seed oil. The proposed pathways were mainly involved in pyrimidine metabolism, one-carbon metabolism, amino acid metabolism, glycolysis and the tricarboxylic acid (TCA) cycle. Hepatic transcriptomics based on Illumina RNA-Seq sequencing showed that hemp seed oil exerted anti-NASH activities by regulating multiple signaling pathways, e.g., downregulation of the TNF signaling pathway, the IL-17 signaling pathway, the MAPK signaling pathway and the NF-κB signaling pathway, which played a pivotal role in the pathogenesis of NASH. In particular, integration of metabonomic and transcriptomic results suggested that hemp seed oil could attenuate NASH-related liver fibrosis by inhibition of glutaminolysis. These results provided new insights into the hepatoprotective effects of hemp seed oil against MCD diet-induced NASH and hemp seed oil might have potential as an effective therapy for NASH.

A review of edible plant-derived natural compounds for the therapy of liver fibrosis

Liver fibrosis has a high incidence worldwide and is the common pathological basis of many chronic liver diseases. Liver fibrosis is caused by the excessive deposition of extracellular matrix and concomitant collagen accumulation in livers and can lead to the development of liver cirrhosis and even liver cancer. A large number of studies have provided evidence that liver fibrosis can be blocked or even reversed by appropriate medical interventions. However, the antifibrosis drugs with ideal clinical efficacy are still insufficient. The edible plant-derived natural compounds have been reported to exert effective antifibrotic effects with few side-effects, representing a kind of promising source for the treatment of liver fibrosis. In this article, we reviewed the current progress of the natural compounds derived from dietary plants in the treatment of liver fibrosis, including phenolic compounds (capsaicin, chlorogenic acid, curcumin, ellagic acid, epigallocatechin-3-gallate, resveratrol, sinapic acid, syringic acid, vanillic acid and vitamin E), flavonoid compounds (genistein, hesperidin, hesperetin, naringenin, naringin and quercetin), sulfur-containing compounds (S-allylcysteine, ergothioneine, lipoic acid and sulforaphane) and other compounds (betaine, caffeine, cucurbitacin B, lycopene, α-mangostin, γ-mangostin, ursolic acid, vitamin C and yangonin). The pharmacological effects and related mechanisms of these compounds in in-vivo and in-vitro models of liver fibrosis are focused.

Oroxylin A regulates cGAS DNA hypermethylation induced by methionine metabolism to promote HSC senescence

Relevant studies have recognized the important role of hepatic stellate cell (HSC) senescence in anti-liver fibrosis. Cellular senescence is believed to be regulated by the cGAS-STING signaling pathway. However, underlying exact mechanisms of cGAS-STING pathway in hepatic stellate cell senescence are still unclear. Here, we found that Oroxylin A could promote senescence in HSC by activating the cGAS-STING pathway. Moreover, activation of the cGAS-STING pathway was dependent on DNMT3A downregulation, which suppressed cGAS gene DNA methylation. Interestingly, the attenuation of DNMT activity relied on the reduction of methyl donor SAM level. Noteworthy, the downregulation of SAM levels implied the imbalance of methionine cycle metabolism, and MAT2A was considered to be an important regulatory enzyme in metabolic processes. In vivo experiments also indicated that Oroxylin A induced senescence of HSCs in mice with liver fibrosis, and DNMT3A overexpression partly offset this effect. In conclusion, we discovered that Oroxylin A prevented the methylation of the cGAS gene by preventing the production of methionine metabolites, which promoted the senescence of HSCs. This finding offers a fresh hypothesis for further research into the anti-liver fibrosis mechanism of natural medicines.

Overview of Methionine Adenosyltransferase 2A (MAT2A) as an Anticancer Target: Structure, Function, and Inhibitors

Methionine adenosyltransferase 2A (MAT2A) is a rate-limiting enzyme in the methionine cycle that primarily catalyzes the synthesis of S-adenosylmethionine (SAM) from methionine and adenosine triphosphate (ATP). MAT2A has been recognized as a therapeutic target for the treatment of cancers. Recently, a few MAT2A inhibitors have been reported, and three entered clinical trials to treat solid tumorsor lymphoma with MTAP loss. This review aims to summarize the current understanding of the roles of MAT2A in cancer and the discovery of MAT2A inhibitors. Furthermore, a perspective on the use of MAT2A inhibitors for the treatment of cancer is also discussed. We hope to provide guidance for future drug design and optimization via analysis of the binding modes of known MAT2A inhibitors.

Emerging roles of Sirtuins in alleviating alcoholic liver Disease: A comprehensive review

Sirtuins (SIRTs), a NAD⁺ family of dependent deacetylases, are involved in the regulation of various human diseases. Recently, accumulating evidence has uncovered number of substrates and crucial roles of SIRTs in the pathogenesis of alcoholic liver disease (ALD). However, systematic reports are still lacking, so this review provides a comprehensive profile of the crucial physiological functions of SIRTs and its role in attenuating ALD, including alcoholic liver steatosis, steatohepatitis, and fibrosis. SIRTs play beneficial roles in energy/lipid metabolism, oxidative stress, inflammatory response, mitochondrial homeostasis, autophagy and necroptosis of ALD via regulating multiple signaling transduction pathways such as AMPK, LKB1, SREBP1, Lipin1, PGC-1α, PPARα/γ, FoxO1/3a, Nrf2/p62, mTOR, TFEB, RIPK1/3, HMGB1, NFATc4, NF-κB, TLR4, NLRP3, P2X7R, MAPK, TGF1β/Smads and Wnt/β-catenin. In addition, the mechanism and clinical application of natural/ synthetic SIRTs agonists in ALD are summarized, which provide a new idea for the treatment of ALD and basic foundation for further studies into target drugs.

Anti-Lung Cancer Activities of 1,2,3-Triazole Curcumin Derivatives via Regulation of the MAPK/NF-κB/STAT3 Signaling Pathways

In this study, a series of curcumin derivatives containing 1,2,3-triazole were designed and synthesized, and their inhibitory activities against the proliferation of lung cancer cells were studied. Compound 5 k (3,4-dichlorobenzyltriazole methyl curcumin) had the best activity against A549 cells, with a half-maximal inhibitory concentration (IC₅₀ ) of 2.27 μM, which was approximately 10 times higher than that of the lead curcumin and higher than that of gefitinib (IC₅₀ =8.64 μM). Western blotting revealed that 5 k increased the phosphorylation levels of p38, c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK). Compound 5 k also promoted the expression of the inhibitor of nuclear factor-κB (IκBα) and decreased that of nuclear factor-κB (NF-κB), signal transducer and activator of transcription 3 (STAT3), and β-catenin. Therefore, 5 k suppresses A549 cell proliferation by activating the mitogen-activated protein kinases and suppressing NF-κB/STAT3 signaling pathways. So, 5 k can potentially be used for treating non-small cell lung cancer.