Baicalin Protects Against 17α-Ethinylestradiol-Induced Cholestasis via the Sirtuin 1/Hepatic Nuclear Receptor-1α/Farnesoid X Receptor Pathway

Baicalin attenuated metabolic dysfunction-associated fatty liver disease by suppressing oxidative stress and inflammation via the p62-Keap1-Nrf2 signalling pathway in db/db mice

Metabolic dysfunction-associated fatty liver disease (MAFLD) is the main cause of chronic liver disease. Baicalin (Bai), a bioactive molecule found in Scutellaria baicalensis Georgi, possesses antioxidant and antiinflammatory properties. These activities suggest Bai could be a promising therapeutic agent against NAFLD; however, its specific effects and underlying mechanism are still not clear. This study aims to explore the effect of Bai to attenuate MAFLD and associated molecular mechanisms. Bai (50, 100 or 200 mg/kg) was orally administered to db/db mice with MAFLD for 4 weeks or db/m mice as the normal control. Bai markedly attenuated lipid accumulation, cirrhosis and hepatocytes apoptosis in the liver tissues of MAFLD mice, suggesting strong ability to attenuate MAFLD. Bai significantly reduced proinflammatory biomarkers and enhanced antioxidant enzymes, which appeared to be modulated by the upregulated p62-Keap1-Nrf2 signalling cascade; furthermore, cotreatment of Bai and all-trans-retinoic acid (Nrf2 inhibitor) demonstrated markedly weakened liver protective effects by Bai and its induced antioxidant and antiinflammatory responses. The present study supported the use of Bai in attenuating MAFLD as a promising therapeutic agent, and its strong mechanism of action in association with the upregulating the p62-keap1-Nrf2 pathway.

Ethanol extract of Polygonatum cyrtonema Hua mitigates non-alcoholic steatohepatitis in mice

Background

Polygonum cyrtonema Hua is a kind of traditional Chinese botanic drug. Modern pharmacological research has confirmed that Polygonum cyrtonema Hua is able to alleviate nonalcoholic fatty liver disease, but the precise mechanism requires further investigation. This study investigated the protective effects and underlying mechanisms of Polygonatum cyrtonema ethanol extract (PCE) against Non-alcoholic steatohepatitis (NASH) in mice.

Methods

UHPLC-MS/MS was utilized to analyze the metabolites of PCE. The NASH mouse model was establishment in C57BL/6J mice via high-fat diet (HFD) feeding for 12 weeks, and from the 9th week, mice were gavaged with PCE (100, 300, and 900 mg/kg/day), simvastatin (4 mg/kg) or saline. One hand, liver injury was assessed by serum enzymes, biochemistry, and histopathology; On the other hand, RNA-seq, qPCR, and Western blot were employed to investigate the related molecular mechanisms.

Results

211 metabolites were identified through UHPLC-MS/MS analysis. PCE ameliorated HFD induced liver injury and improved hepatocellular degeneration and steatosis in a dose-dependent way. PCE restored the expression of AMPK, SIRT1, SREBP1 and PPAR-α both in mRNA and protein levels. RNAseq identified unique gene expression profiles in response to high-fat diet (HFD) compared to the PCE treatments. HFD-induced DEGs were attenuated or abolished following PCE treatments. Ingenuity pathway analysis of RNA-seq data revealed key canonical pathways and upstream molecules regulated by PCE.

Conclusion

Our findings confirm the ability of PCE in alleviating NASH and underscores AMPK/SIRT1 pathway as a potential theraputic target for NASH treatment.

MiR-128-3p mediates MRP2 internalization in estrogen-induced cholestasis through targeting PDZK1

Estrogens have been reported to cause dysfunction in biliary transport systems, thereby inducing cholestasis. Multidrug resistance-associated protein 2 (MRP2) is a transporter responsible for independent bile flow. Emerging evidence indicates that PDZ domain containing 1 (PDZK1) regulates localization of MRP2; however, PDZK1’s role and regulatory machinery in MRP2-mediated estrogen-induced cholestasis (EIC) remain unclear. Herein, in a mouse model of EIC, we observed downregulated PDZK1 expression in the liver and enhanced intracellular domain MRP2 internalization. Notably, expression of miR-128-3p, a potential biomarker of estrogen-related cholestasis discovered by our group, was significantly elevated. We demonstrated that miR-128-3p targeted the 3’-untranslated region of PDZK1 in EIC and consequently promoted MRP2 internalization. Accordingly, miR-128-3p suppression upregulated PDZK1, thereby suppressing MRP2 internalization and significantly attenuating cholestatic liver disease. Furthermore, we observed MRP2 internalization and PDZK1 downregulation, as well as excessive miR-128-3p, in clinical samples from patients with cholestatic liver injury. Overall, our findings illustrate that miR-128-3p inhibits PDZK1 expression, thereby inhibiting the membrane localization of MRP2 in EIC. Enhancing or restoring PDZK1 expression might therefore have therapeutic potential for cholestatic liver injury.

Protective effects of cilostazol via the HNF1α/FXR signalling pathway and anti-apoptotic mechanisms in a rat model of estrogen-induced intrahepatic cholestasis

Currently, there is a lack of targeted medications for estrogen-induced intrahepatic cholestasis (EIC) and the primary objective in managing this condition is to safeguard liver function. Consequently, this study was conducted to examine the pharmacological efficacy of cilostazol (CTZ) in the management of EIC and explore its underlying mechanisms through the use of an animal model. Thirty female Sprague-Dawley rats were divided into five groups of six animals each: Normal group, 17-ethinylestradiol (EE)-induced intrahepatic cholestasis group, EE + ursodeoxycholic acid (UDCA)-treated group, EE + CTZ (5 mg/kg)-treated group, and EE + CTZ (10 mg/kg)-treated group. It was found that the therapeutic efficacy of UDCA and low dosage of CTZ (5 mg/kg) was comparable. Nevertheless, when CTZ was administered at a dose of 10 mg/kg, it resulted in the normalization of all liver function parameters, oxidative stress, and pro-inflammatory markers, together with improvement in the histopathological derangements and hepatocytic apoptosis. These effects were mediated through the activation of the hepatocyte nuclear factor-1 alpha (HNF1α)/Farnesoid X receptor (FXR) pathway with subsequent down-regulation of the bile acids (BAs) synthesis enzyme; cholesterol 7α-hydroxylase (CYP7A1), and up-regulation of the BAs-metabolizing enzyme; cytochrome P450 (CYP)3A1 and the bile salt export pump; BSEP. Therefore, the administration of CTZ in a dose-dependent manner can protect against EIC through regulating the HNF1α/FXR pathway and anti-apoptotic mechanisms. This implies that CTZ exhibits considerable promise as a therapeutic agent for the treatment of cholestatic liver disorders.

Baicalin ameliorates heat stress-induced hepatic injury and intestinal microecology dysbiosis in late gestational mice

Heat stress (HS) disrupts intestinal microbiota, glycolipid metabolism, and hepatic mitochondrial function in late gestational mice. Baicalin (BAI), a Chinese herbal medicine known for its heat-clearing and anti-inflammatory properties, has shown promise in modulating intestinal microecology and mitigating inflammation in various organs. This study investigates whether baicalin attenuates HS-induced intestinal microbial dysbiosis and liver damage in pregnant mice during late gestation. Twenty-four pregnant mice were randomly assigned to four groups, including thermoneutral (TN) (24 ± 1 ℃), HS (35 ± 1 ℃), HS+BAI200 (oral gavaged with 200 mg/kg BW of BAI), and HS+BAI400 (oral gavaged with 400 mg/kg BW of BAI). 400 mg/kg BAI treatment markedly decreased the rectal temperature and increased fetal weight in HS pregnant mice. Furthermore, 400 mg/kg BAI administration effectively ameliorated HS-induced hepatic damage and lipid disorders, reducing HSP70, AST, and ALT levels while increasing TG concentration. Notably, it activated a network of genes involved in lipid synthesis, including fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), and oxidation, such as peroxisome proliferator-activated receptor alpha (PPARα), carnitine palmityl transferase 1 beta (CPT1β). Moreover, BAI intervention restored the intestinal morphology and barrier function, evidenced by increased intestinal villus height, the ratio of villus height to crypt depth, and colonic goblet cells numbers. 400 mg/kg of BAI treatment up-regulated the expression of tight junction proteins, such as claudin-1 and Zonula Occludens-1 (ZO-1), in the jejunum and ileum, counteracting HS-induced downregulation. High-throughput sequencing showed that BAI treatment altered cecal microbial composition, increasing the relative abundance of beneficial Bacteroidota and decreasing Deferribacterota, Turicibacter, and Akkermansia. Spearman's correlation analysis highlighted significant correlations between differential cecal microbiota and physiological indexes. In conclusion, BAI administration alleviated adverse impacts in heat-exposed mice during late gestation, improving maternal physiological parameters, and ameliorating hepatic damage with altered cecal microbial composition. The findings suggest that BAI may regulate the gut-liver axis by modulating intestinal morphology, microecology, and hepatic function.

Natural bioactive compounds-The promising candidates for the treatment of intestinal failure-associated liver disease

Parenteral nutrition (PN) is a life-saving procedure conducted to maintain a proper nutritional state in patients with severe intestinal failure who cannot be fed orally. A serious complication of PN therapy is liver failure, known as intestinal failure-associated liver disease (IFALD). The pathogenesis of IFALD is multifactorial and includes inhibition of the farnesoid X receptor (FXR) by PN components, bacteria translocation from impaired intestines, and intravenous line-associated bloodstream infection. Currently, the most frequently researched therapeutic option for IFALD is using lipid emulsions based on soy or fish oil and, therefore, free from phytosterols known as FXR antagonists. Nevertheless, the potential side effects of the lack of soybean oil delivery seem to outweigh the benefits, especially in the pediatric population. PN admixture provides all the necessary nutrients; however, it is deprived of exogenous natural bioactive compounds (NBCs) of plant origin, such as polyphenols, characterized by health-promoting properties. Among them, many substances have already been known to demonstrate the hepatoprotective effect in various liver diseases. Therefore, searching for new therapeutic options for IFALD among NBCs seems reasonable and potentially successful. This review summarizes the recent research on polyphenols and their use in treating various liver diseases, especially metabolic dysfunction-associated steatotic liver diseases (MASLD). Furthermore, based on scientific reports, we have described the molecular mechanism of action of selected NBCs that exert hepatoprotective properties. We also summarized the current knowledge on IFALD pathogenesis, described therapeutic options undergoing clinical trials, and presented the future perspective of the potential use of NBCs in PN therapy.

Recent advances in Scutellariae radix: A comprehensive review on ethnobotanical uses, processing, phytochemistry, pharmacological effects, quality control and influence factors of biosynthesis

Background

Scutellariae radix (SR) is the dried root of Scutellaria baicalensis Georgi. It has a long history of ethnic medicinal use, traditionally recognized for its efficacy in clearing heat， drying dampness, eliminating fire， removing toxins , stopping bleeding and tranquilizing fetus to prevent miscarriage. Clinically, it is used to treat cold, fever, migraine, hand-foot-and-mouth diseases, liver cancer and inflammatory diseases.

Purpose

The review aims to provide a comprehensive reference on the ethnobotanical uses, processing, phytochemistry, pharmacological effect, quality control and influence factors of biosynthesis for a deeper understanding of SR.

Results and conclusion

A total of 210 isolated components have been reported in the literature, including flavonoids and their glycosides, phenylpropanoids, phenylethanoid glycosides, phenolic acids, volatile components, polysaccharides and others. The extract of SR and its main flavonoids such as baicalin, baicalein, wogonin, wogonoside, and scutellarin showed antioxidant, anti-inflammatory, anti-tumor, antiviral, hepatoprotective, and neuroprotective effects. However, further studies are required to elucidate its mechanisms of action and clinical applications. The pharmacodynamic evaluation based on traditional efficacy should be conducted. Although various analytical methods have been established for the quality control of SR, there are gaps in the research regarding efficacy-related quality markers and the development of quality control standards for its processed products. The regulatory mechanisms of flavonoids biosynthesis remain to be explored while the influence of environmental and transcription factors on the biosynthesis have been studied. In conclusion, SR is a promising herbal medicine with significant potential for future development.

Leonurine Exerts Anti-Inflammatory Effects in Lipopolysaccharide (LPS)-Induced Endometritis by Modulating Mouse JAK-STAT/PI3K-Akt/PPAR Signaling Pathways

Endometritis is a common disease in postpartum cows, characterized by delayed uterine recovery due to endometrial inflammation. Although antibiotics and hormones are commonly used, they have certain limitations. One potential alternative is using motherwort extract, specifically leonurine, which exhibits anti-inflammatory properties. However, leonurine's exact molecular mechanism of action remains unclear. In this study, 40 mice were randomly divided into four groups: a control group, endometritis model group, LPS + leonurine group (30 mg/kg), and LPS + dexamethasone group (5 mg/kg). Transcriptomic analysis revealed that leonurine modulates multiple signaling pathways, including JAK-STAT/PI3K-Akt, and influences the expression of key genes, such as Prlr, Socs2, Col1a1, and Akt1. Furthermore, leonurine effectively reduces levels of inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, and IL-1β (p < 0.01), which play a crucial role in regulating acute endometritis. Additionally, leonurine helps maintain cholesterol homeostasis and attenuates inflammation through the peroxisome proliferator-activated receptor (PPAR) signaling pathway by modulating genes such as Cyp27a1, Hmgcs1, and Scd2. These findings suggest that leonurine has a protective effect against LPS-induced endometritis and that its anti-inflammatory properties involve multiple pathways and targets, which are potentially mediated by regulating signaling pathways such as JAK-STAT/PI3K-Akt and PPAR.

Antioxidant and anti‑inflammatory effects of esculin and esculetin (Review)

Fraxinus chinensis Roxb is a deciduous tree, which is distributed worldwide and has important medicinal value. In Asia, the bark of Fraxinus chinensis Roxb is a commonly used traditional Chinese medicine called Qinpi. Esculetin is a coumarin compound derived from the bark of Fraxinus chinensis Roxb and its glycoside form is called esculin. The aim of the present study was to systematically review relevant literature on the antioxidant and anti-inflammatory effects of esculetin and esculin. Esculetin and esculin can promote the expression of various endogenous antioxidant proteins, such as superoxide dismutase, glutathione peroxidase and glutathione reductase. This is associated with the activation of the nuclear factor erythroid-derived factor 2-related factor 2 signaling pathway. The anti-inflammatory effects of esculetin and esculin are associated with the inhibition of the nuclear factor κ-B and mitogen-activated protein kinase inflammatory signaling pathways. In various inflammatory models, esculetin and esculin can reduce the expression levels of various proinflammatory factors such as tumor necrosis factor-α, interleukin (IL)-1β and IL-6, thereby inhibiting the development of inflammation. In summary, esculetin and esculin may be promising candidates for the treatment of numerous diseases associated with inflammation and oxidative stress, such as ulcerative colitis, acute lung and kidney injury, lung cancer, acute kidney injury.

Plant-derived flavonoids are a potential source of drugs for the treatment of liver fibrosis

Liver fibrosis is a dynamic pathological process that can be triggered by any chronic liver injury. If left unaddressed, it will inevitably progress to the severe outcomes of liver cirrhosis or even hepatocellular carcinoma. In the past few years, the prevalence and fatality of hepatic fibrosis have been steadily rising on a global scale. As a result of its intricate pathogenesis, the quest for pharmacological interventions targeting liver fibrosis has remained a formidable challenge. Currently, no pharmaceuticals are exhibiting substantial clinical efficacy in the management of hepatic fibrosis. Hence, it is of utmost importance to expedite the development of novel therapeutics for the treatment of this condition. Various research studies have revealed the ability of different natural flavonoid compounds to alleviate or reverse hepatic fibrosis through a range of mechanisms, which are related to the regulation of liver inflammation, oxidative stress, synthesis and secretion of fibrosis-related factors, hepatic stellate cells activation, and proliferation, and extracellular matrix synthesis and degradation by these compounds. This review summarizes the progress of research on different sources of natural flavonoids with inhibitory effects on liver fibrosis over the last decades. The anti-fibrotic effects of natural flavonoids have been increasingly studied, making them a potential source of drugs for the treatment of liver fibrosis due to their good efficacy and biosafety.

The role of sirtuin1 in liver injury: molecular mechanisms and novel therapeutic target

Liver disease is a common and serious threat to human health. The progression of liver diseases is influenced by many physiologic processes, including oxidative stress, inflammation, bile acid metabolism, and autophagy. Various factors lead to the dysfunction of these processes and basing on the different pathogeny, pathology, clinical manifestation, and pathogenesis, liver diseases are grouped into different categories. Specifically, Sirtuin1 (SIRT1), a member of the sirtuin protein family, has been extensively studied in the context of liver injury in recent years and are confirmed the significant role in liver disease. SIRT1 has been found to play a critical role in regulating key processes in liver injury. Further, SIRT1 seems to cause divers outcomes in different types of liver diseases. Recent studies have showed some therapeutic strategies involving modulating SIRT1, which may bring a novel therapeutic target. To elucidate the mechanisms underlying the role of sirtuin1 in liver injury and its potentiality as a therapeutic target, this review outlines the key signaling pathways associated with sirtuin1 and liver injury, and discusses recent advances in therapeutic strategies targeting sirtuin1 in liver diseases.

Paeoniflorin loaded liposomes modified with glycyrrhetinic acid for liver-targeting: preparation, characterization, and pharmacokinetic study

OBJECTIVE

To enhance the retention times and therapeutic efficacy of paeoniflorin (PF), a liver-targeted drug delivery system has been developed using glycyrrhetinic acid (GA) as a ligand.

SIGNIFICANCE

The development and optimization of GA-modified PF liposomes (GPLs) have shown promising potential for targeted delivery to the liver, opening up new possibilities for liver disease treatment.

METHODS

This study aimed to identify the best prescriptions using single-factor experiments and response surface methodology. The formulation morphology was determined using transmission electron microscopy. Tissue distribution was observed through in vivo imaging, and pharmacokinetic studies were conducted.

RESULTS

The results indicated that GPLs, prepared using the thin film dispersion method and response surface optimization, exhibited well-dispersed and uniformly sized particles. The in vitro release rate of GPLs was slower compared to PF monomers, suggesting a sustained release effect. The liver-targeting ability of GA resulted in stronger fluorescence signals in the liver for targeted liposomes compared to non-targeted liposomes. Furthermore, pharmacokinetic studies demonstrated that GPLs significantly prolonged the residence time of PF in the bloodstream, thereby contributing to prolonged efficacy.

CONCLUSION

These findings suggest that GPLs are more effective than PF monomers in terms of controlling drug release and delivering drugs to specific targets, highlighting the potential of PF as a liver-protective drug.

Inhibition of integrin receptors reduces extracellular matrix levels, ameliorating benign prostate hyperplasia

Although a high prevalence of benign prostate hyperplasia (BPH) has been documented, the risk factors are poorly understood. Metabolic syndrome increases the risk of BPH. Succinylation, a type of posttranslational modification, mostly targets metabolic processes. The level of succinylation was investigated in 4 BPH patients and 4 healthy controls. Additionally, 176 patients with BPH were analyzed by using pan-antisuccinyllysine antibody blotting. TMT-labeling proteomic and sc-RNAseq Cellchat analyses were employed to identify key signaling factors involved in the development of BPH. In vivo and in vitro experiments were used to confirm the role of integrin receptors. The global succinylation level in BPH was higher than that in the healthy prostate. Positive correlations of prostate volume with IHC score sand urodynamics testing were found in large clinical cohorts. The extracellular matrix (ECM), metabolic processes and immune signaling were involved in succinylation in BPH, as indicated by using TMT-labeling proteomic analysis, and this finding was also confirmed by sc-RNAseq CellChat analysis. The proteins upregulated in SIRT5 knockout WPMY-1 cells were also enriched in the extracellular matrix and metabolic processes. More importantly, integrin receptor inhibition in a mouse model of BPH significantly ameliorated prostate hyperplasia. High levels of succinylation modifications were found in BPH, and succinylated proteins influenced the activation of the ECM. Inhibition of ECM signaling further ameliorated prostate hyperplasia in mice.

Consecutive baicalin treatment relieves its accumulation in rats with intrahepatic cholestasis by increasing MRP2 expression

Baicalin, an important flavonoid isolated from Scutellaria baicalensis Georgi, is a Chinese herb widely used in clinical practice. We previously reported the in vivo accumulation of baicalin in rats with intrahepatic cholestasis (IHC) after a single dose. However, the effects of the long-term administration of baicalin on its pharmacokinetics are unknown. Thus, we investigated the disposition of baicalin in normal rats and those with IHC after single and multiple consecutive administrations. In addition, we further investigated the effect of baicalin on multidrug resistance protein 2 (MRP2) in vivo to explore the underlying mechanism. In our study, the liquid chromatography-mass spectrometry (LC-MS) method established to determine baicalin concentrations in rat blood was simple, specific, and with linearity (R² = 0.9980) in the range of 1.01-506.00 μg/mL. The relative standard deviations (RSD) for intra-day and inter-day precision were not more than 10.55%, and the intra-day and inter-day accuracies were 94.94%-109.13%. The recovery rate and stability were in line with the requirements of the quantitative analysis of biological samples as stated in the Chinese Pharmacopoeia (2020 Edition). Compared with that in normal rats, the C_max and t_1/2 increased significantly in EE-induced rats with IHC, whereas the clearance (CL) decreased after a single administration of baicalin. However, the area under the curve decreased, CL increased, and the t_1/2 was shortened after the continuous administration of baicalin in the IHC rat model compared with the single administration of baicalin, and the pharmacokinetic characteristics were similar to those in normal rats. Moreover, MRP2 expression increased in rats with IHC with the continuous administration of baicalin. Continuous baicalin intervention could effectively reduce its accumulation in rats with IHC, and the mechanism may be attributed to its enhancement of MRP2 expression.

Paeoniflorin alleviates 17α-ethinylestradiol-induced cholestasis via the farnesoid X receptor-mediated bile acid homeostasis signaling pathway in rats

Cholestasis, characterized by disturbance of bile formation, is a common pathological condition that can induce several serious liver diseases. As a kind of trigger, estrogen-induced cholestasis belongs to drug-induced cholestasis. Paeoniflorin is the most abundant bioactive constituent in Paeonia lactiflora Pall., Paeonia suffruticosa Andr., or Paeonia veitchii Lynch, a widely used herbal medicine for treating hepatic disease over centuries in China. However, the pharmacologic effect and mechanism of paeoniflorin on estrogen-induced cholestasis remain unclear. In this experiment, the pharmacological effect of paeoniflorin on EE-induced cholestasis in rats was evaluated comprehensively for the first time. Ultra-high-performance liquid chromatography coupled with Q-Exactive orbitrap mass spectrometer was used to monitor the variation of bile acid levels and composition. It was demonstrated that paeoniflorin alleviated 17α-ethinylestradiol (EE)-induced cholestasis dose-dependently, characterized by a decrease of serum biochemical indexes, recovery of bile flow, amelioration of hepatic and ileal histopathology, and reduction of oxidative stress. In addition, paeoniflorin intervention restored EE-disrupted bile acid homeostasis in enterohepatic circulation. Further mechanism studies using western blot, quantitative Real-Time PCR, and immunohistochemical showed that paeoniflorin could upregulate hepatic efflux transporters expression but downregulate hepatic uptake transporter expression. Meanwhile, paeoniflorin reduced bile acids synthesis by repressing cholesterol 7α-hydroxylase in hepatocytes. Paeoniflorin affected the above transporters and enzyme via activation of a nuclear receptor, farnesoid X receptor (FXR), which was recognized as a vital regulator for maintaining bile acid homeostasis. In conclusion, paeoniflorin alleviated EE-induced cholestasis and maintained bile acid homeostasis via FXR-mediated regulation of bile acids transporters and synthesis enzyme. The findings indicated that paeoniflorin might exert a potential therapeutic medicine for estrogen-induced cholestasis.

Ginsenosides Restore Lipid and Redox Homeostasis in Mice with Intrahepatic Cholestasis through SIRT1/AMPK Pathways

Intrahepatic cholestasis (IC) occurs when the liver and systemic circulation accumulate bile components, which can then lead to lipid metabolism disorders and oxidative damage. Ginsenosides (GS) are pharmacologically active plant products derived from ginseng that possesses lipid-regulation and antioxidation activities. The purpose of this study was to evaluate the possible protective effects of ginsenosides (GS) on lipid homeostasis disorder and oxidative stress in mice with alpha-naphthylisothiocyanate (ANIT)-induced IC and to investigate the underlying mechanisms. A comprehensive strategy via incorporating pharmacodynamics and molecular biology technology was adopted to investigate the therapeutic mechanisms of GS in ANIT-induced mice liver injury. The effects of GS on cholestasis were studied in mice that had been exposed to ANIT-induced cholestasis. The human HepG2 cell line was then used in vitro to investigate the molecular mechanisms by which GS might improve IC. The gene silencing experiment and liver-specific sirtuin-1 (SIRT1) knockout (SIRT1^LKO) mice were used to further elucidate the mechanisms. The general physical indicators were assessed, and biological samples were collected for serum biochemical indexes, lipid metabolism, and oxidative stress-related indicators. Quantitative PCR and H&E staining were used for molecular and pathological analysis. The altered expression levels of key pathway proteins (Sirt1, p-AMPK, Nrf2) were validated by Western blotting. By modulating the AMPK protein expression, GS decreased hepatic lipogenesis, and increased fatty acid β-oxidation and lipoprotein lipolysis, thereby improving lipid homeostasis in IC mice. Furthermore, GS reduced ANIT-triggered oxidative damage by enhancing Nrf2 and its downstream target levels. Notably, the protective results of GS were eliminated by SIRT1 shRNA in vitro and SIRT1^LKO mice in vivo. GS can restore the balance of the lipid metabolism and redox in the livers of ANIT-induced IC models via the SIRT1/AMPK signaling pathway, thus exerting a protective effect against ANIT-induced cholestatic liver injury.

Role of baicalin as a potential therapeutic agent in hepatobiliary and gastrointestinal disorders: A review

Baicalin is a natural bioactive compound derived from Scutellaria baicalensis, which is extensively used in traditional Chinese medicine. A literature survey demonstrated the broad spectrum of health benefits of baicalin such as antioxidant, anticancer, anti-inflammatory, antimicrobial, cardio-protective, hepatoprotective, renal protective, and neuroprotective properties. Baicalin is hydrolyzed to its metabolite baicalein by the action of gut microbiota, which is further reconverted to baicalin via phase 2 metabolism in the liver. Many studies have suggested that baicalin exhibits therapeutic potential against several types of hepatic disorders including hepatic fibrosis, xenobiotic-induced liver injury, fatty liver disease, viral hepatitis, cholestasis, ulcerative colitis, hepatocellular and colorectal cancer. During in vitro and in vivo examinations, it has been observed that baicalin showed a protective role against liver and gut-associated abnormalities by modifying several signaling pathways such as nuclear factor-kappa B, transforming growth factor beta 1/SMAD3, sirtuin 1, p38/mitogen-activated protein kinase/Janus kinase, and calcium/calmodulin-dependent protein kinase kinaseβ/adenosine monophosphate-activated protein kinase/acetyl-coenzyme A carboxylase pathways. Furthermore, baicalin also regulates the expression of fibrotic genes such as smooth muscle actin, connective tissue growth factor, β-catenin, and inflammatory cytokines such as interferon gamma, interleukin-6 (IL-6), tumor necrosis factor-alpha, and IL-1β, and attenuates the production of apoptotic proteins such as caspase-3, caspase-9 and B-cell lymphoma 2. However, due to its low solubility and poor bioavailability, widespread therapeutic applications of baicalin still remain a challenge. This review summarized the hepatic and gastrointestinal protective attributes of baicalin with an emphasis on the molecular mechanisms that regulate the interaction of baicalin with the gut microbiota.

Screening of Biomarkers and Toxicity Mechanisms of Rifampicin-Induced Liver Injury Based on Targeted Bile Acid Metabolomics

Rifampicin (RIF) is a critical first-line drug for tuberculosis. However, long-term or high-dose treatment with RIF can induce severe liver injury; the underlying mechanism of this effect has not yet been clarified. This study was performed to screen reliable and sensitive biomarkers in serum bile acids (BAs) using targeted BA metabolomics and evaluate the toxicity mechanisms underlying RIF-induced liver injury through the farnesoid x receptor (Fxr)-multidrug resistance-associated proteins (Mrps) signaling pathway. Thirty-two Institute of Cancer Research mice were randomly divided into four groups, and normal saline, isoniazid 75 mg/kg + RIF 177 mg/kg (RIF-L), RIF-L, or RIF 442.5 mg/kg (RIF-H) was orally administered by gavage for 21 days. After treatment, changes in serum biochemical parameters, hepatic pathological conditions, BA levels, Fxr expression, and BA transporter levels were measured. RIF caused notable liver injury and increased serum cholic acid (CA) levels. Decline in the serum secondary BAs (deoxycholic acid, lithocholic acid, taurodeoxycholic acid, and tauroursodeoxycholic acid) levels led to liver injury in mice. Serum BAs were subjected to metabolomic assessment using partial least squares discriminant and receiver operating characteristic curve analyses. CA, DCA, LCA, TDCA, and TUDCA are potential biomarkers for early detection of RIF-induced liver injury. Furthermore, RIF-H reduced hepatic BA levels and elevated serum BA levels by suppressing the expression of Fxr and Mrp2 messenger ribonucleic acid (mRNA) while inducing that of Mrp3 and Mrp4 mRNAs. These findings provide evidence for screening additional biomarkers based on targeted BA metabolomics and provide further insights into the pathogenesis of RIF-induced liver injury.

Scutellaria baicalensis and its constituents baicalin and baicalein as antidotes or protective agents against chemical toxicities: a comprehensive review

Scutellaria baicalensis (SB), also known as the Chinese skullcap, has a long history of being used in Chinese medicine to treat a variety of conditions ranging from microbial infections to metabolic syndrome and malignancies. Numerous studies have reported that treatment with total SB extract or two main flavonoids found in its root and leaves, baicalin (BA) and baicalein (BE), can prevent or alleviate the detrimental toxic effects of exposure to various chemical compounds. It has been shown that BA and BE are generally behind the protective effects of SB against toxicants. This paper aimed to review the protective and therapeutic effects of SB and its main components BA and BE against chemical compounds that can cause intoxication after acute or chronic exposure and seriously affect different vital organs including the brain, heart, liver, and kidneys. In this review paper, we had a look into a total of 221 in vitro and in vivo studies from 1995 to 2021 from the scientific databases PubMed, Scopus, and Web of Science which reported protective or therapeutic effects of BA, BE, or SB against drugs and chemicals that one might be exposed to on a professional or accidental basis and compounds that are primarily used to simulate disease models. In conclusion, the protective effects of SB and its flavonoids can be mainly attributed to increase in antioxidants enzymes, inhibition of lipid peroxidation, reduction of inflammatory cytokines, and suppression of apoptosis pathway.

Pathogenesis of Liver Fibrosis and Its TCM Therapeutic Perspectives

Liver fibrosis is a pathological process of abnormal tissue proliferation in the liver caused by various pathogenic factors, which will further develop into cirrhosis or even hepatocellular carcinoma if liver injury is not intervened in time. As a diffuse progressive liver disease, its clinical manifestations are mostly excessive deposition of collagen-rich extracellular matrix resulting in scar formation due to liver injury. Hepatic fibrosis can be caused by hepatitis B and C, fatty liver, alcohol, and rare diseases such as hemochromatosis. As the metabolic center of the body, the liver regulates various vital activities. During the development of fibrosis, it is influenced by many other factors in addition to the central event of hepatic stellate cell activation. Currently, with the increasing understanding of TCM, the advantages of TCM with multiple components, pathways, and targets have been demonstrated. In this review, we will describe the factors influencing liver fibrosis, focusing on the effects of cells, intestinal flora, iron death, signaling pathways, autophagy and angiogenesis on liver fibrosis, and the therapeutic effects of herbal medicine on liver fibrosis.

Baicalin provides protection against fluoxetine-induced hepatotoxicity by modulation of oxidative stress and inflammation

BACKGROUND

Fluoxetine is one of the most widely prescribed anti-depressant drugs belonging to the category of selective serotonin reuptake inhibitors. Long-term fluoxetine treatment results in hepatotoxicity. Baicalin, a natural compound obtained from the Chinese herb Scutellaria baicalensis is known to have antioxidant, hepatoprotective and anti-inflammatory effects. However, the beneficial effects of baicalin against fluoxetine-induced hepatic damage have not previously been reported.

AIM

To evaluate the protective action of baicalin in fluoxetine-induced liver toxicity and inflammation.

METHODS

Male albino Wistar rats were divided into seven groups. Group 1 was the normal control. Oral fluoxetine was administered at 10 mg/kg body weight to groups 2, 3, 4 and 5. In addition, groups 3 and 4 were also co-administered oral baicalin (50 mg/kg and 100 mg/kg, respectively) while group 5 received silymarin (100 mg/kg), a standard hepatoprotective compound for comparison. Groups 6 and 7 were used as a positive control for baicalin (100 mg/kg) and silymarin (100 mg/kg), respectively. All treatments were carried out for 28 d. After sacrifice of the rats, biomarkers of oxidative stress [superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), glutathione-S-transferase (GST), advanced oxidation protein products (AOPP), malondialdehyde (MDA)], and liver injury [alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), total protein, albumin, bilirubin] were studied in serum and tissue using standard protocols and diagnostic kits. Inflammatory markers [tumor necrosis factor (TNF-α), interleukin (IL)-6, IL-10 and interferon (IFN)-γ] in serum were evaluated using ELISA-based kits. The effect of baicalin on liver was also analyzed by histopathological examination of tissue sections.

RESULTS

Fluoxetine-treated rats showed elevated levels of the serum liver function markers (total bilirubin, ALT, AST, and ALP) and inflammatory markers (TNF-α, IL-6, IL-10 and IFN-γ), with a decline in total protein and albumin levels. Biochemical markers of oxidative stress such as SOD, CAT, GST, GSH, MDA and AOPP in the liver tissue homogenate were also altered indicating a surge in reactive oxygen species leading to oxidative damage. Histological examination of liver tissue also showed degeneration of hepatocytes. Concurrent administration of baicalin (50 and 100 mg/kg) restored the biomarkers of oxidative stress, inflammation and hepatic damage in serum as well as in liver tissues to near normal levels.

CONCLUSION

These findings suggested that long-term treatment with fluoxetine leads to oxidative stress via the formation of free radicals that consequently cause inflammation and liver damage. Concurrent treatment with baicalin alleviated fluoxetine-induced hepatotoxicity and liver injury by regulating oxidative stress and inflammation.

Quercetin Reduces Oxidative Stress and Apoptosis by Inhibiting HMGB1 and Its Translocation, Thereby Alleviating Liver Injury in ACLF Rats

Background

Acute on chronic liver failure (ACLF) is a syndrome of acute liver failure that occurs on the basis of chronic liver disease, which is characterized by a rapid deterioration in a short period and high mortality. High mobility group box 1 (HMGB1) may be involved in the pathological process of ACLF; its specific role remains to be further elucidated. Our previous studies have shown that quercetin (Que) exerts anti-oxidant and anti-apoptotic effects by inhibiting HMGB1 in vitro. The present study aimed to investigate the effect of Que on liver injury in ACLF rats.

Methods

The contents of ALT, AST, TBiL, and PT time of rats in each group were observed. HE staining was used to detect liver pathology. The levels of oxidative stress indicators such as MDA, GSH, and 4-HNE in the rat liver were detected. TUNEL assay was used to detect apoptosis in rat hepatocytes. Immunofluorescence and western blot analysis were performed to explore the protective effect of Que on ACLF rats and the underlying mechanism.

Results

The results showed that Que could reduce the increase of serum biochemical indices, improve liver pathology, and reduce liver damage in ACLF rats. Further results confirmed that Que reduced the occurrence of oxidative stress and apoptosis of hepatocytes, and these reactions may aggravate the progress of ACLF. Meanwhile, the results of immunofluorescence and western blotting also confirmed that the expression of HMGB1 and extranuclear translocation in ACLF rat hepatocytes were significantly increased, which was alleviated by the treatment of Que. In addition, when cotreated with glycyrrhizin (Gly), an inhibitor of HMGB1, the inhibition of Que on HMGB1 and its translocation, apoptosis and oxidative stress, and the related proteins of HMGB1-mediated cellular pathway have been significantly enhanced.

Conclusion

Thus, Que alleviates liver injury in ACLF rats, and its mechanism may be related to oxidative stress and apoptosis caused by HMGB1 and its translocation.

The Pathological Mechanisms of Estrogen-Induced Cholestasis: Current Perspectives

Estrogens are steroid hormones with a wide range of biological activities. The excess of estrogens can lead to decreased bile flow, toxic bile acid (BA) accumulation, subsequently causing intrahepatic cholestasis. Estrogen-induced cholestasis (EIC) may have increased incidence during pregnancy, and within women taking oral contraception and postmenopausal hormone replacement therapy, and result in liver injury, preterm birth, meconium-stained amniotic fluid, and intrauterine fetal death in pregnant women. The main pathogenic mechanisms of EIC may include deregulation of BA synthetic or metabolic enzymes, and BA transporters. In addition, impaired cell membrane fluidity, inflammatory responses and change of hepatocyte tight junctions are also involved in the pathogenesis of EIC. In this article, we review the role of estrogens in intrahepatic cholestasis, and outlined the mechanisms of EIC, providing a greater understanding of this disease.

Paeoniflorin Protects against ANIT-Induced Cholestatic Liver Injury in Rats via the Activation of SIRT1-FXR Signaling Pathway

Paeoniflorin (PF), a water-soluble monoterpene glycoside, is initially isolated from the dried roots of Paeonia lactiflora Pall., which has effects on ameliorating cholestasis in our previous study. However, comprehensive approaches for understanding the protective effects and mechanisms underlying cholestatic liver injury from the regulating of bile acid metabolism have not been sufficiently elucidated. This study was aimed to explore the effectiveness as well as potential mechanism of PF on alpha-naphthylisothiocyanate (ANIT)-induced cholestatic liver injury. Rats with cholestasis induced by ANIT was used to evaluate the protective effects and mechanism of PF by regulating SIRT1/FXR and NF-κB/NLRP3 signaling pathway. Rats were intragastrically administrated with ANIT to establish cholestatic liver injury model. Serum levels of ALT, AST, TBA, TBIL, ALP, γ-GT and ALB in rats were detected. The histopathology of the liver of rats was analyzed in vivo. The relative mRNA expression and protein expression levels of IL-18, IL-1β, TNF-α, HO-1, Nrf2, TLR4, NLRP3, Caspase-1, ASC, NF-κB, FXR, and SIRT1 in liver of rats were investigated. The results showed that the serum indexes and the liver histopathology were significantly improved by PF. The overexpression of IL-18, IL-1β, TNF-α, NLRP3, ASC, and Caspase-1 in liver was markedly reduced by PF. Furthermore, PF dramatically increased the mRNA and protein expressions of SIRT1, FXR, HO-1, and Nrf2, but decreased NF-κB p65 and TLR4 levels in liver of rats. Taken together, the protective effects of PF on cholestatic liver injury were possibly related to the activation of the SIRT1/FXR and inhibition of NF-κB/NLRP3 inflammasome signaling pathway. These findings might provide a potential protection for cholestatic liver injury.

Kinsenoside Alleviates 17α-Ethinylestradiol-Induced Cholestatic Liver Injury in Rats by Inhibiting Inflammatory Responses and Regulating FXR-Mediated Bile Acid Homeostasis

Cholestasis is an important predisposing factor of liver diseases, such as hepatocyte necrosis, liver fibrosis and primary biliary cirrhosis. In this study, we aimed to investigate the effects of Kinsenoside (KD), a natural active ingredient of Anoectochilus roxburghii, on estrogen-induced cholestatic liver injury in Sprague-Dawley rats and the underlying mechanism. The rats were randomly divided into six groups: control group, model group, low-dose KD group (50 mg/kg body weight, KD-L), medium-dose KD group (100 mg/kg body weight, KD-M), high-dose KD group (200 mg/kg body weight, KD-H) and ursodeoxycholic acid group (40 mg/kg body weight, UDCA). 17α-Ethinylestradiol (EE) was used to establish an experimental animal model of estrogen-induced cholestasis (EIC). The results demonstrated that KD alleviated liver pathologic damage, serum biochemical status and inhibited hepatocellular microstructure disorder and bile duct hyperplasia in EE-induced cholestatic rats. Mechanically, KD alleviated EE-induced cholestatic liver injury by inhibiting inflammatory responses and regulating bile acid homeostasis. Concretely, KD reduced the expression of IL-1β and IL-6 by inhibiting NF-κB p65 to suppress EE-mediated inflammation in rat liver. KD enhanced the expression of FXR and inhibited EE-mediated reduction of FXR in vitro and in vivo. It was the potential mechanism that KD mitigates cholestasis by increasing efflux and inhibiting uptake of bile acids via FXR-mediated induction of bile salt export pump (BSEP) and reduction of Na⁺-dependent taurocholate cotransport peptide (NTCP) to maintain bile acid homeostasis. Moreover, KD repressed the bile acid synthesis through reducing the expression of synthetic enzyme (CYP7A1), thereby normalizing the expression of metabolic enzyme (SULT2A1) of bile acid. In conclusion, our results revealed that KD may be an effective drug candidate for the treatment of cholestasis.

Chinese herbal medicine: Fighting SARS-CoV-2 infection on all fronts

ETHNOPHARMACOLOGICAL RELEVANCE

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causes coronavirus disease 2019 (COVID-19), a highly pathogenic virus that has spread rapidly across the entire world. There is a critical need to develop safe and effective drugs, especially broad-spectrum antiviral and organ protection agents in order to treat and prevent this dangerous disease. It is possible that Chinese herbal medicine may play an essential role in the treatment of patients with SARS-CoV-2 infection.

AIM OF THE REVIEW

We aim to review the use of Chinese herbal medicine in the treatment of COVID-19 both in vitro and in clinical practice. Our goal was to provide a better understanding of the potential therapeutic effects of Chinese herbal medicine and to establish a "Chinese protocol" for the treatment of COVID-19.

MATERIALS AND METHODS

We systematically reviewed published research relating to traditional Chinese herbal medicines and the treatment of SARS-CoV-2 from inception to the 6^th January 2021 by screening a range of digital databases (Web of Science, bioRxiv, medRxiv, China National Knowledge Infrastructure, X-MOL, Wanfang Data, Google Scholar, PubMed, Elsevier, and other resources) and public platforms relating to the management of clinical trials. We included the active ingredients of Chinese herbal medicines, monomer preparations, crude extracts, and formulas for the treatment of COVID-19.

RESULTS

In mainland China, a range of Chinese herbal medicines have been recognized as very promising anti-SARS-CoV-2 agents, including active ingredients (quercetagetin, osajin, tetrandrine, proscillaridin A, and dihydromyricetin), monomer preparations (xiyanping injection, matrine-sodium chloride injection, diammonium glycyrrhizinate enteric-coated capsules, and sodium aescinate injection), crude extracts (Scutellariae Radix extract and garlic essential oil), and formulas (Qingfei Paidu decoction, Lianhuaqingwen capsules, and Pudilan Xiaoyan oral liquid). All these agents have potential activity against SARS-CoV-2 and have attracted significant attention due to their activities both in vitro and in clinical practice.

CONCLUSIONS

As a key component of the COVID-19 treatment regimen, Chinese herbal medicines have played an irreplaceable role in the treatment of SARS-CoV-2 infection. The "Chinese protocol" has already demonstrated clear clinical importance. The use of Chinese herbal medicines that are capable of inhibiting SARS-Cov-2 infection may help to address this immediate unmet clinical need and may be attractive to other countries that are also seeking new options for effective COVID-19 treatment. Our analyses suggest that countries outside of China should also consider protocols involving Chinese herbal medicines combat this fast-spreading viral infection.

Da-Huang-Xiao-Shi decoction protects against3, 5-diethoxycarbonyl-1,4-dihydroxychollidine-induced chronic cholestasis by upregulating bile acid metabolic enzymes and efflux transporters

ETHNOPHARMACOLOGICAL RELEVANCE

Chronic cholestasis is a usual clinical pathological process in hepatopathy and has few treatment options; it is classified under the category of jaundice in Chinese medicine. Da-Huang-Xiao-Shi decoction (DHXSD) is a classic Chinese prescription which is used to treat jaundice.

AIM OF THE STUDY

We aimed to examine the protective effect of DHXSD on liver and its potential mechanism of action against chronic cholestasis.

MATERIALS AND METHODS

Chronic cholestasis was induced using 3, 5-diethoxycarbonyl-1,4-dihydroxychollidine (DDC) in mice. Mice were then administered DHXSD intragastrically at doses of 3.68, 7.35, and 14.70 g/kg for four weeks followed by further analyses. Serum biochemical indices and liver pathology were explored. Eighteen individual bile acids (BAs) in mice serum and liver were quantified using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The expression of BA related metabolic enzymes, transporters, along with nuclear receptor farnesoid X receptor (FXR) was detected by real-time qPCR and Western blot.

RESULTS

DHXSD treatment reduced the serum biochemical indices, ameliorated pathological injury, and improved the disordered BA homeostasis. Mice treated with DHXSD showed significantly upregulated expression of the metabolic enzymes, cytochrome P450 2b10 (Cyp2b10), Cyp3a11, and UDP-glucuronosyltransferase 1a1 (Ugt1a1); and the bile acid transporters, multidrug resistance protein 2 (Mdr2), bile salt export pump (Bsep), and multidrug resistance-associated protein 3 (Mrp3). DHXSD treatment also significantly upregulated FXR expression in mice with DDC-induced chronic cholestasis.

CONCLUSIONS

DHXSD exerted protective effects on chronic cholestasis in DDC-treated mice by alleviating the disordered homeostasis of BAs through increased expression of BA related metabolic enzymes and efflux transporters.

Rodent models of cholestatic liver disease: A practical guide for translational research

Cholestatic liver disease denotes any situation associated with impaired bile flow concomitant with a noxious bile acid accumulation in the liver and/or systemic circulation. Cholestatic liver disease can be subdivided into different types according to its clinical phenotype, such as biliary atresia, drug-induced cholestasis, gallstone liver disease, intrahepatic cholestasis of pregnancy, primary biliary cholangitis and primary sclerosing cholangitis. Considerable effort has been devoted to elucidating underlying mechanisms of cholestatic liver injuries and explore novel therapeutic and diagnostic strategies using animal models. Animal models employed according to their appropriate applicability domain herein play a crucial role. This review provides an overview of currently available in vivo animal models, fit-for-purpose in modelling different types of cholestatic liver diseases. Moreover, a practical guide and workflow is provided which can be used for translational research purposes, including all advantages and disadvantages of currently available in vivo animal models.

Baicalin triggers apoptosis, inhibits migration, and enhances anti-tumor immunity in colorectal cancer via TLR4/NF-κB signaling pathway

Aberrant activation of the nuclear factor-kappa B (NF-κB) signaling pathway is closely implicated in colorectal cancer (CRC) growth, metastasis, and immune escape. In the present study, we reported natural derived compound of baicalin (BA), an efficient inhibitor of NF-κB, with good anti-tumor effect on CRC. CCK8 and colony formation assays showed that Baicalin significantly inhibit viability and proliferation in HCT-116 and CT26 cells. Additionally, Baicalin dramatically triggers mitochondria-mediated apoptosis in both HCT-116 and CT-26 cells, which is evidenced by loss of mitochondrial membrane potential and elevated cellular reactive oxygen species level. Treatment with Baicalin suppresses migration and invasion of CT26 cells by impairing TLR4/NF-κB signaling pathway. What's more, administration of Baicalin significantly retarded tumor growth rate in a subcutaneous xenograft tumor mouse model of CT26 cells. Treatment with Baicalin could ameliorate tumor immunosuppressive environment by downregulation of PD-L1 expression and proportion of myeloid-derived suppressor cells (MDSCs) and upregulation of percent of CD4⁺ and CD8⁺ T cells in CT26 tumors, thus improving anti-tumor immunity. In conclusion, our study demonstrated that baicalin triggers apoptosis, inhibits migration, and enhances anti-tumor immunity in colorectal cancer via TLR4/NF-κB signaling pathway, suggesting it might serve as a potential candidate drug for the treatment of CRC. PRACTICAL APPLICATIONS: In the present study, we reported natural derived compound of baicalin (BA), an efficient inhibitor of NF-κB, with good anti-tumor effect on CRC. We demonstrated that baicalin triggers mitochondria-mediated apoptosis, inhibits migration, and improves anti-tumor immunity in colorectal cancer via TLR4/NF-κB signaling pathway.

Pharmacological properties of baicalin on liver diseases: a narrative review

Baicalin is the main active component of Scutellaria baicalensis, widely used in traditional Chinese medicine thanks to its various pharmacological effects, such as anti-tumor, anti-inflammatory, and antibacterial properties, as well as cardiovascular, hepatic, and renal protective effect. Recently, the protective effects of baicalin on liver disease have received much more attention. Several studies showed that baicalin protects against several types of liver diseases including viral hepatitis, fatty liver disease, xenobiotic induced liver injury, cholestatic liver injury, and hepatocellular carcinoma, with a variety of pharmacological mechanisms. A comprehensive understanding of the mechanism of baicalin can provide a valuable reference for its clinical use, but up to now, no narrative review is available that summarizes the pharmacological effects of baicalin to clarify its potential use in the treatment of liver diseases. Therefore, this review summarizes the progress of baicalin research and the underlying mechanism in the treatment of various liver diseases, to promote further research and its clinical application.

Baicalin and the liver-gut system: Pharmacological bases explaining its therapeutic effects

With the development of high-throughput screening and bioinformatics technology, natural products with a range of pharmacological targets in multiple diseases have become important sources of new drug discovery. These compounds are derived from various plants, including the dried root of Scutellaria baicalensis Georgi, which is often used as a traditional Chinese herb named Huangqin, a popular medication used for thousands of years in China. Many studies have shown that baicalin, an extract from Scutellaria baicalensis Georgi, exerts various protective effects on liver and gut diseases. Baicalin plays a therapeutic role mainly by mediating downstream apoptosis and immune response pathways induced by upstream oxidative stress and inflammation. During oxidative stress regulation, PI3K/Akt/NRF2, Keap-1, NF-κB and HO-1 are key factors associated with the healing effects of baicalin on NAFLD/NASH, ulcerative colitis and cholestasis. In the inflammatory response, IL-6, IL-1β, TNF-α, MIP-2 and MIP-1α are involved in the alleviation of NAFLD/NASH, cholestasis and liver fibrosis by baicalin, as are TGF-β1/Smads, STAT3 and NF-κB. Regarding the apoptosis pathway, Bax, Bcl-2, Caspase-3 and Caspase-9 are key factors related to the suppression of hepatocellular carcinoma and attenuation of liver injury and colorectal cancer. In addition to immune regulation, PD-1/PDL-1 and TLR4-NF-κB are correlated with the alleviation of hepatocellular carcinoma, ulcerative colitis and colorectal cancer by baicalin. Moreover, baicalin regulates intestinal flora by promoting the production of SCFAs. Furthermore, BA is involved in the interactions of the liver-gut axis by regulating TGR5, FXR, bile acids and the microbiota. In general, a comprehensive analysis of this natural compound was conducted to determine the mechanism by which it regulates bile acid metabolism, the intestinal flora and related signaling pathways, providing new insights into the pharmacological effects of baicalin. The mechanism linking the liver and gut systems needs to be elucidated to draw attention to its great clinical importance.

Alcohol and Liver Clock Disruption Increase Small Droplet Macrosteatosis, Alter Lipid Metabolism and Clock Gene mRNA Rhythms, and Remodel the Triglyceride Lipidome in Mouse Liver

Heavy alcohol drinking dysregulates lipid metabolism, promoting hepatic steatosis – the first stage of alcohol-related liver disease (ALD). The molecular circadian clock plays a major role in synchronizing daily rhythms in behavior and metabolism and clock disruption can cause pathology, including liver disease. Previous studies indicate that alcohol consumption alters liver clock function, but the impact alcohol or clock disruption, or both have on the temporal control of hepatic lipid metabolism and injury remains unclear. Here, we undertook studies to determine whether genetic disruption of the liver clock exacerbates alterations in lipid metabolism and worsens steatosis in alcohol-fed mice. To address this question, male liver-specific Bmal1 knockout (LKO) and flox/flox (Fl/Fl) control mice were fed a control or alcohol-containing diet for 5 weeks. Alcohol significantly dampened diurnal rhythms of mRNA levels in clock genes Bmal1 and Dbp, phase advanced Nr1d1/REV-ERBα, and induced arrhythmicity in Clock, Noct, and Nfil3/E4BP4, with further disruption in livers of LKO mice. Alcohol-fed LKO mice exhibited higher plasma triglyceride (TG) and different time-of-day patterns of hepatic TG and macrosteatosis, with elevated levels of small droplet macrosteatosis compared to alcohol-fed Fl/Fl mice. Diurnal rhythms in mRNA levels of lipid metabolism transcription factors (Srebf1, Nr1h2, and Ppara) were significantly altered by alcohol and clock disruption. Alcohol and/or clock disruption significantly altered diurnal rhythms in mRNA levels of fatty acid (FA) synthesis and oxidation (Acaca/b, Mlycd, Cpt1a, Fasn, Elovl5/6, and Fads1/2), TG turnover (Gpat1, Agpat1/2, Lpin1/2, Dgat2, and Pnpla2/3), and lipid droplet (Plin2/5, Lipe, Mgll, and Abdh5) genes, along with protein abundances of p-ACC, MCD, and FASN. Lipidomics analyses showed that alcohol, clock disruption, or both significantly altered FA saturation and remodeled the FA composition of the hepatic TG pool, with higher percentages of several long and very long chain FA in livers of alcohol-fed LKO mice. In conclusion, these results show that the liver clock is important for maintaining temporal control of hepatic lipid metabolism and that disrupting the liver clock exacerbates alcohol-related hepatic steatosis.