Protective Effect and Mechanism of Plant-Based Monoterpenoids in Non-alcoholic Fatty Liver Diseases

Benzoate glycosides from Gentiana scabra Bge. and their lipid-lowering activity

Seven undescribed benzoate glycosides (1-7) and five known ones (8-12) were isolated from the rhizomes of Gentiana scabra Bge. Their structures were characterized by comprehensive NMR and MS spectroscopic data analysis. The lipid-lowering effects of these compounds were evaluated by measuring the triglyceride (TG) contents and intracellular lipid droplets (LDs) in oleic acid (OA)-treated HepG2 cells. The results showed that compounds 1, 5, 7, and 11 significantly reduced the TG content at 20 μM, and the Bodipy staining displayed that OA enhanced the levels of LDs in the cell, while these compounds reversed the lipid accumulation caused by OA. These findings provide a basis for further development and utilization of G. scabra as a natural source of potential lipid-lowering agents.

Protective effects of syringic acid in nonalcoholic fatty liver in rats through regulation of Nrf2/HO-1 signaling pathway

Nonalcoholic fatty liver disease (NAFLD) is an alarming ailment that leads to severe liver damage and increases the risk of serious health conditions. The prevalence of NAFLD due to oxidative stress could be mitigated by plant-derived antioxidants. This study aims to investigate the effects of syringic acid (SA) on NAFLD in a high-fat diet (HFD) rat model. Twenty-four rats were randomly divided into four groups (n = 6): normal control, HFD, SA-administered HFD, and positive control SA on a normal diet. Rats in the normal control and positive control groups received a normal diet, and the remaining groups received an HFD for 8 weeks. SA (20 mg/kg b.w.) was orally (gavage) administered for 8 weeks. Lipid profiles were controlled by SA against HFD-fed rats (p < 0.05). SA reduced the serum aspartate aminotransferase and alanine aminotransferase levels by 70%-190%. SA also suppressed pro-inflammatory cytokines and attenuated histopathological and immunohistochemical changes against HFD-fed rats. SA reversed oxidative stress by suppressing the malondialdehyde formation by 82% and replenished the nonenzymatic and enzymatic antioxidant activities (p < 0.05). Gene expressions of nuclear factor-erythroid 2-related factor/heme oxygenase 1 (Nrf2/HO-1) were elevated in SA-treated rats. Ameliorative effects of SA on NAFLD induced by an HFD in rats were prominent through the reversal of oxidative stress and inflammation, regulated by an intrinsic mechanism of defense against oxidative stress, the Nrf2/HO-1 pathway.

TFEB activator tanshinone IIA and derivatives derived from Salvia miltiorrhiza Bge. Attenuate hepatic steatosis and insulin resistance

ETHNOPHARMACOLOGICAL RELEVANCE

Salvia miltiorrhiza Bge. (SMB) is an herbal medicine extensively used for improving metabolic disorders, including Nonalcoholic fatty liver disease (NAFLD). However, the potential material basis and working mechanism still remained to be elucidated.

AIM OF THE STUDY

To find potential ingredients for therapy of NAFLD by high content screening and further verify the efficacy on restoring hepatic steatosis and insulin resistance, and clarify the potential working mechanism.

MATERIALS AND METHODS

The mouse transcription factor EB (Tfeb) in preadipocytes was knocked out by CRISPR-Cas9 gene editing. High content screening of TFEB nuclear translocation was performed to identify TFEB activators. The effect of candidate compounds on reducing lipid accumulation was evaluated using Caenorhabditis elegans (C. elegans). Then the role of Salvia miltiorrhiza extract (SMB) containing Tanshinone IIA and the derivatives were further investigated on high-fat diet (HFD) fed mice. RNA-seq was performed to explore potential molecular mechanism of SMB. Finally, the gut microbiota diversity was evaluated using 16S rRNA sequencing to investigate the protective role of SMB on regulating gut microbiota homeostasis.

RESULTS

Knockout of Tfeb led to excessive lipid accumulation in adipocytes while expression of TFEB homolog HLH-30 in C. elegans (MAH240) attenuated lipid deposition. Screening of TFEB activators identified multiple candidates from Salvia miltiorrhiza, all of them markedly induced lysosome biogenesis in HepG2 cells. One of the candidate compounds Tanshinone IIA significantly decreased lipid droplet deposition in HFD fed C. elegans. Administration of SMB on C57BL/6J mice via gastric irrigation at the dose of 15 g/kg/d markedly alleviated hepatic steatosis, restored serum lipid profile, and glucose tolerance. RNA-seq showed that gene expression profile was altered and the genes related to lipid metabolism were restored. The disordered microbiome was remodeled by SMB, Firmicutes and Actinobacteriotawere notably reduced, Bacteroidota and Verrucomicrobiota were significantly increased.

CONCLUSION

Taken together, the observations presented here help address the question concerning what were the main active ingredients in SMB for alleviating NAFLD, and established that targeting TFEB was key molecular basis for the efficacy of SMB.

Transcriptomic and proteomic investigations identify PI3K-akt pathway targets for hyperthyroidism management in rats via polar iridoids from radix Scrophularia

High-polarity iridoids from Radix Scrophulariae (R. Scrophulariae) offer a range of benefits, including anti-inflammatory, antioxidant, antitumour, antibacterial, antiviral, and antiallergic effects. Although previous studies have indicated the potential of R. Scrophulariae for hyperthyroidism prevention and treatment, the specific active compounds involved and their mechanisms of action are not fully understood. This study explored the effects of high-polarity iridoid glycosides from R. Scrophulariae on hyperthyroidism induced in rats by levothyroxine sodium. The experimental design included a control group, a hyperthyroidism model group, and a group treated with iridoid glycosides. Serum triiodothyronine (T3) and thyroxine (T4) levels were quantified using an enzyme-linked immunosorbent assay (ELISA). Transcriptomic and proteomic analyses were applied to liver samples to identify differentially expressed genes and proteins. These analyses were complemented by trend analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. The effectiveness of key factors was further examined through molecular biology techniques. ELISA results indicated a notable increase in T3 and T4 in the hyperthyroid rats, which was significantly mitigated by treatment with iridoid glycosides. Transcriptomic analysis revealed 6 upregulated and 6 downregulated genes in the model group, showing marked improvement following treatment. Proteomic analysis revealed changes in 30 upregulated and 50 downregulated proteins, with improvements observed upon treatment. The PI3K-Akt signalling pathway was investigated through KEGG enrichment analysis. Molecular biology methods verified the upregulation of Spp1, Thbs1, PI3K, and Akt in the model group, which was reversed in the treatment group. This study revealed that highly polar iridoids from R. Scrophulariae can modulate the Spp1 gene and Thbs1 protein via the PI3K-Akt signalling pathway, suggesting a therapeutic benefit for hyperthyroidism and providing a basis for drug development targeting this condition.

Echinops Asteraceae extract guards against malathion-induced liver damage via minimizing oxidative stress, inflammation, and apoptosis

Malathion (MAL) is one of the highly toxic organophosphorus (OP) compounds that induces hepatotoxicity. Echinops. ritro leaves extract (ERLE) is traditionally used in the treatment of bacterial/fungal infections. This study's goal was to investigate the potential of extracts from ERLE against hepatotoxicity induced by MAL in male albino rats. Four equal groups of forty mature male albino rats were created: The rats in the first group used as a control. The second group of rats received ERLE orally. The third group received MAL. ERLE and MAL were administered to the fourth group of rats. Six-week treatment groups were conducted. Using lipid peroxidation indicators [malondialdehyde (MDA), alanine aminotransferase (ALT), aspartate aminotransferase (AST)], oxidative stress markers [catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx)], apoptotic markers [Bcl-2 & caspase-3] and tumor necrosis factor alpha (TNF-α). Rats treated with MAL underwent a significant increase on MDA, ALT, AST, caspase-3 and TNF-α marker with a significant decrease in antioxidant markers [CAT, SOD, GPx] and Bcl-2. Histologically, MAL-treated group's liver sections displayed damaged hepatocytes with collapsed portions, pyknotic nuclei, vacuolated cytoplasm, and congested central veins. Ultra structurally, rat livers treated with MAL showed dilated cisternae of endoplasmic reticulum, swollen mitochondria with disrupted cristae, nuclei with disrupted chromatin content, multiple lysosomes, multiple vacuolations and a disrupted blood sinusoid. With rats treated with ERLE, these alterations were essentially non-existent. It is possible to conclude that ERLE protects against MAL hepatotoxicity, and that this protection is related, at least in part, to its antioxidant activities.

Pharmacology of bioactive compounds from plant extracts for improving non-alcoholic fatty liver disease through endoplasmic reticulum stress modulation: A comprehensive review

Background

Non-alcoholic fatty liver disease (NAFLD) is a prevalent chronic liver condition with significant clinical implications. Emerging research indicates endoplasmic reticulum (ER) stress as a critical pathogenic factor governing inflammatory responses, lipid metabolism and insulin signal transduction in patients with NAFLD. ER stress-associated activation of multiple signal transduction pathways, including the unfolded protein response, disrupts lipid homeostasis and substantially contributes to NAFLD development and progression. Targeting ER stress for liver function enhancement presents an innovative therapeutic strategy. Notably, the natural bioactive compounds of plant extracts have shown potential for treating NAFLD by reducing the level of ER stress marker proteins and mitigating inflammation, stress responses, and de novo lipogenesis. However, owing to limited comprehensive reviews, the effectiveness and pharmacology of these bioactive compounds remain uncertain.

Objectives

To address the abovementioned challenges, the current review categorizes the bioactive compounds of plant extracts by chemical structures and properties into flavonoids, phenols, terpenoids, glycosides, lipids and quinones and examines their ameliorative potential for NAFLD under ER stress.

Methods

This review systematically analyses the literature on the interactions of bioactive compounds from plant extracts with molecular targets under ER stress, providing a holistic view of NAFLD therapy.

Results

Bioactive compounds from plant extracts may improve NAFLD by alleviating ER stress; reducing lipid synthesis, inflammation, oxidative stress and apoptosis and enhancing fatty acid metabolism. This provides a multifaceted approach for treating NAFLD.

Conclusion

This review underscores the role of ER stress in NAFLD and the potential of plant bioactive compounds in treating this condition. The molecular mechanisms by which plant bioactive compounds interact with their ER stress targets provide a basis for further exploration in NAFLD management.

Promising hepatoprotective agents from the natural sources: a study of scientific evidence

Background

Natural bioactive components derived from plant secondary metabolites have been pronounced as valuable alternatives for anticipating and subsiding hepatotoxic effects and its chronic complications based on experimental verification. The focus of this review is to elucidate the commonly used modern medicine for the treatment of liver disease and how major phytoconstituents have been tested for hepatoprotective activity, mechanism of action of some promising agents from natural sources, and clinical trial data for treating in patients with different liver diseases by the aid of natural phytoconstituents.

Main text

The review shows fifteen major isolated phytoconstituents, their biological sources, chemical structures, utilized plant parts, type of extracts used, hepatoprotective assay method, and their possible mechanism of action on the hepatoprotection. Nine promising hepatoprotective leads from natural sources with their chemistry and hepatoprotective mechanism are mentioned briefly. The review further includes the recent clinical trial studies of some hepatoprotective leads and their clinical outcome with different liver disease patients. Scientific studies revealed that antioxidant properties are the central mechanism for the phytoconstituents to subside different disease pathways by upsurging antioxidant defense system of cells, scavenging free radicals, down surging lipid peroxidation, improving anti-inflammatory potential, and further protecting the hepatic cell injury. In this review, we summarize recent development of natural product-based hepatoprotective leads and their curative potential for various sort of liver diseases. Furthermore, the usefulness of hit and lead molecules from natural sources for significant clinical benefit to discover new drug molecule and downsizing the problems of medication and chemical-induced hepatotoxic effects is extrapolated.

Conclusion

Further research are encouraged to elucidate the pharmacological principle of these natural-based chemical agents which will stimulate future pharmaceutical development of therapeutically beneficial hepatoprotective regimens.

Targeted modulation of gut microbiota by traditional Chinese medicine and natural products for liver disease therapy

The gut microbiota not only constitutes intestinal microenvironment homeostasis and human health but also exerts indispensable roles in the occurrence and progression of multiple liver diseases, including alcohol-related liver disease, nonalcoholic fatty liver disease, autoimmune liver disease and liver cancer. Given the therapeutic status of these diseases, their prevention and early therapy are crucial, and the detailed mechanism of gut microbiota in liver disease urgently needs to be explored. Meanwhile, multiple studies have shown that various traditional Chinese medicines, such as Si Miao Formula, Jiangzhi Granules, Liushen Capsules, Chaihu-Shugan Power, Cassiae Semen and Gynostemma, as well as some natural products, including Costunolide, Coprinus comatus polysaccharide, Antarctic krill oil, Oridonin and Berberine, can repair liver injury, improve fatty liver, regulate liver immunity, and even inhibit liver cancer through multiple targets, links, and pathways. Intriguingly, the aforementioned effects demonstrated by these traditional Chinese medicines and natural products have been shown to be closely related to the gut microbiota, directly driving the strategy of traditional Chinese medicines and natural products to regulate the gut microbiota as one of the breakthroughs in the treatment of liver diseases. Based on this, this review comprehensively summarizes and discusses the characteristics, functions and potential mechanisms of these medicines targeting gut microbiota during liver disease treatment. Research on the potential effects on gut microbiota and the regulatory mechanisms of traditional Chinese medicine and natural products provides novel insights and significant references for developing liver disease treatment strategies. In parallel, such explorations will enhance the comprehension of traditional Chinese medicine and natural products modulating gut microbiota during disease treatment, thus facilitating their clinical investigation and application.

New roles of N6-methyladenosine methylation system regulating the occurrence of non-alcoholic fatty liver disease with N6-methyladenosine-modified MYC

Non-alcoholic fatty liver disease (NAFLD) has become a major chronic disease in contemporary society, affected by N6-methyladenosine (m6A) RNA methylation, one of the most common RNA modifications. Compared with healthy control, m6A RNA methyltransferase 3 (METTL3) and METTL14 increased, while Wilms tumor 1-associated protein (WTAP) and RNA-binding motif protein 15 (RBM15) decreased significantly in NAFLD, and the m6A demethylases fat mass and obesity-associated protein (FTO) elevated. Meanwhile, the m6A binding proteins, YT521-B homology (YTH) domain-containing 1 (YTHDC1), YTHDC2, insulin-like growth factor 2 mRNA binding protein 1 (IGF2BP1), heterogeneous nuclear ribonucleoprotein C (HNRNPC), and HNRNPA2B1 were decreased, while eukaryotic translation initiation factor 3 subunit H (EIF3H) was increased significantly. All these changes of m6A regulators had significant differences between healthy control and NAFLD, but no differences between the NAFL and NASH group. The expression level of RBM15, HNRNPC, and HNRNPA2B1 were related to body fat index. RBM15, YTHDC2, HNRNPC, HNRNPA2B1, and EIF3H were related to steatosis. Also, KIAA1429 and YTH domain family 1 (YTHDF1) were related to lobular inflammation. Taken together, m6A regulators were involved in the occurrence of NAFLD. More importantly, abnormal MYC was determined as a key link to m6A regulation of NAFLD. The higher MYC mRNA level was accompanied by higher HDL cholesterol and unsaturated fatty acid proportions, as well as lower fat mass, glucose, and transaminase. Taken together, dysregulation of m6A methylation caused steatosis and fibrosis, affecting the occurrence of NAFLD, and MYC might be its potential target.

Redox-Unlockable Nanoparticle-Based MST1 Delivery System to Attenuate Hepatic Steatosis via the AMPK/SREBP-1c Signaling Axis

To date, few effective treatments have been licensed for nonalcoholic fatty liver disease (NAFLD), which a kind of chronic liver disease. Mammalian sterile 20-like kinase 1 (MST1) is reported to be involved in the development of NAFLD. Thus, we evaluated the suitability of a redox-unlockable polymeric nanoparticle Hep@PGEA vector to deliver MST1 or siMST1 (HCP/MST1 or HCP/siMST1) for NAFLD therapy. The Hep@PGEA vector can efficiently deliver the condensed functional nucleic acids MST1 or siMST1 into NAFLD-affected mouse liver to upregulate or downregulate MST1 expression. The HCP/MST1 complexes significantly improved liver insulin resistance sensitivity and reduced liver damage and lipid accumulation by the AMPK/SREBP-1c pathway without significant adverse events. Instead, HCP/siMST1 delivery exacerbates the NAFLD. The analysis of NAFLD patient samples further clarified the role of MST1 in the development of hepatic steatosis in patients with NAFLD. The MST1-based gene intervention is of considerable potential for clinical NAFLD therapy, and the Hep@PGEA vector provides a promising option for NAFLD gene therapy.

Exploring Anti-Nonalcoholic Fatty Liver Disease Mechanism of Gardeniae Fructus by Network Pharmacology, Molecular Docking, and Experiment Validation

Gardeniae fructus (GF), the fruit from Gardenia jasminoides Ellis, is a traditional Chinese medicine used for the treatment of nonalcoholic fatty liver disease (NAFLD) in the clinic. To explore the hepatoprotective mechanism of GF for the treatment of NAFLD, we proposed a novel strategy that integrated in vivo efficacy evaluation, network pharmacology analysis, molecular docking, and experimental validation. A NAFLD animal model induced by high fat diet (HFD) feed was established, then orally administrated with or without GF. The results showed that GF significantly decreased the levels of serum total cholesterol (TC), lipoprotein cholesterol, triglyceride (TG), alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, free fatty acids, glucose, and insulin and the levels of liver TG, TC, and malondialdehyde compared with the nontreated HFD group. Network pharmacology studies showed that quercetin, oleanolic acid, kaempferol, and geniposide were the main biocompounds in GF that targeted the PPARα and PPARγ genes through regulating the PPAR and AMPK signal pathways to protect against NAFLD. The interactions between bioactive compounds and their corresponding target proteins were analyzed by molecular docking and subsequently confirmed using the qRT-PCR assay. Collectively, GF was a therapeutic drug for the treatment of NAFLD.

Peach Kernel Extracts Inhibit Lipopolysaccharide-Induced Activation of HSC-T6 Hepatic Stellate Cells

There is an important role for hepatic stellate cells (HSCs) in liver fibrosis. As it stands, many traditional Chinese medicine formulations can effectively improve liver fibrosis, whether it is clinically used or in animal studies; however, the efficacy and mechanism of the main formulations remain unclear, including the peach kernel, which contains numerous phytochemicals with a wide range of biological activities. The purpose of this study was to investigate peach kernel's anti-liver fibrosis effects. In this study, peach kernel extracts inhibited lipopolysaccharide (LPS) activation in HSC-T6 cells and the expression of α-smooth muscle actin and connective tissue growth factor induced by LPS in HSC-T6 cells. Furthermore, peach kernel extracts inhibited signal transducers involving protein kinase B and mitogen-activated protein kinase, which regulate downstream genes associated with inflammation. As a result, peach kernel extracts inhibited inflammatory responses and subsequently inhibited LPS-induced transformation of activated HSC-T6 cells.