Molecular updates on berberine in liver diseases: Bench to bedside

Novel evidence in vivo: Berberine ameliorated glucocorticoid-induced post-natal growth retardation by regulating the GH/IGF-1 axis through KMT1A downregulation

BACKGROUND

Glucocorticoids (GCs) are widely used anti-inflammatory agents that inhibit growth in children. However, their mechanisms and effect on the growth hormone (GH)/insulin-like growth factor (IGF)-1 axis remain unclear.

PURPOSE

This study, we aimed to establish a mouse model of GC-induced growth retardation during the critical growth period and explore the underlying mechanisms. Additionally, we aimed to identify novel biomarkers and potential therapeutic agents for GC-induced growth impairment.

METHODS

Four-week-old mice were treated with GCs for two weeks and subsequently assessed for body length, weight, and body composition. Immunohistochemical analysis of the growth plate in the proximal tibia and biochemical assays of blood were performed to evaluate changes in growth plate length and GH/IGF-1 axis. KMT1A expression and its effects on Ghr expression were examined, and the impact of berberine on GC-induced growth retardation was assessed.

RESULTS

GCs significantly reduced growth by impairing growth plate expansion, disrupting the GH/IGF-1 axis, and downregulation of the GH receptor (Ghr) and Igf-1 levels in the liver. These changes were attributed to the upregulation of the H3K9 trimethyltransferase KMT1A, which decreased Ghr transcription in the liver. In vitro screening of natural compounds revealed that berberine chloride hydrate decreased the KMT1A levels and increased GHR levels. Berberine chloride hydrate also effectively ameliorated GC-induced growth retardation by restoring Ghr expression via KMT1A inhibition, thereby enhancing the circulating IGF-1 levels.

CONCLUSION

Overall, our findings highlight the potential of targeting KMT1A using berberine chloride hydrate as an epigenetic modifier to treat GC-induced growth impairment.

Berberine Attenuates Cerulein-Induced Acute Pancreatitis by Modulating Nrf2/NOX2 Signaling Pathway via AMPK Activation

AMP-activated protein kinase (AMPK) is the master regulator of cellular energy which gets activated during energy stress and restores tissue homeostasis. AMPK is widely expressed in the pancreas and is involved in protein synthesis. In cerulein-induced acute pancreatitis (AP), diminished AMPK activity in the pancreatic tissue may be associated with pancreatic inflammation and oxidative stress. Our results demonstrated that berberine (BR) treatment produced significant decrease in plasma amylase and lipase levels and improved histopathological features in AP mice model. Myeloperoxidase (MPO) activity indicated that BR suppressed the infiltration of neutrophils in pancreas. BR treatment markedly decreased the levels of proinflammatory cytokines including interleukins (IL)-6, IL-1β, and tumor necrosis factor-α (TNF-α) via inhibition of nicotinamide adenine dinucleotide phosphate oxidase 2 (NOX2) expression. In addition, BR activates the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling and inhibits cerulein-induced oxidative-nitrosative stress. Mechanistically, we found inhibition of AMPK activity in cerulein-induced AP, while BR-treated animals showed marked increase in the AMPK expression. Together, our study indicated that BR-mediated AMPK activation in pancreatic tissues demonstrated attenuation of cerulein-induced oxidative stress and inflammation. Based on our observations, further exploration of this promising natural product against AP and associated complications may lead to promising therapeutic options.

A 30-Day Randomized Crossover Human Study on the Safety and Tolerability of a New Micellar Berberine Formulation with Improved Bioavailability

Background/Objectives: Berberine is a naturally occurring compound found in several plants and has been traditionally used for its various health benefits. However, its poor bioavailability limits its therapeutic potential. Berberine LipoMicel® is a novel micellar formulation of berberine, microencapsulated within an emulsified matrix, designed to enhance bioavailability and bioactivity. This study aims to evaluate its safety, ensuring that improved bioavailability does not introduce new safety concerns. Methods: To assess its safety, a randomized, double-blind, placebo-controlled crossover study with a minimum 4-week washout period was conducted in 19 healthy participants over 30 days. The participants received 1000 mg of the treatment daily (i.e., 2 capsules/d), and their capillary blood was analyzed every week to monitor for changes in established safety markers related to liver and kidney function, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (TB), creatinine, fasting glucose (GLU), HbA1c, and various electrolytes. Additionally, potential side effects were recorded through the collection of weekly health questionnaires to determine treatment tolerability. Results: Compared to placebo, no statistically significant changes in any of the safety markers related to liver or kidney health were detected. Within-group analysis revealed a significant reduction of total cholesterol (TC) in females after 30 days of Berberine LipoMicel® treatment. Although not significant, both male and female participants showed a noticeable improvement in the mean AST, potentially signaling a hepatoprotective effect. As for tolerability, no adverse events were reported by any of the participants. Conclusions: Based on these findings, despite higher bioavailability of berberine in a newly formulated delivery system (LipoMicel®), the treatment was found to be safe and well tolerated by human participants, with no significant deviations in blood chemistry that would indicate safety concerns over a period of 30 days.

Potentiation of Sorafenib's Action by Berberine via Suppression of the mTOR Signaling Pathway in Human Hepatoma Cells

Sorafenib (SOR) is the first-line treatment for advanced hepatocellular carcinoma (HCC), while its therapeutic efficacy is unsatisfactory. Clinical studies suggest that combination therapy holds significant therapeutic potential to enhance SOR's efficacy. Berberine (BBR), a multiple-targeted agent, shows great promise in combination therapy. This study aims to investigate whether BBR can enhance SOR's effect in vitro and in vivo, and to elucidate the underlying mechanisms. We selected BEL-7402 cells and Huh7 cells for our investigation and explored the effect of BBR on the sensitivity of SOR using the cell counting kit-8 assay, cell cycle analysis, reactive oxygen species (ROS) detection assay, Annexin V/PI staining, western blotting, and the construction of tumor xenograft models. Our findings demonstrate that BBR not only enhances the proliferation-inhibitory effects, apoptosis, and ROS generation induced by SOR, but also sensitizes tumor xenograft models to SOR. Notably, this synergistic effect is found to depend on AMPK activation and the inhibition of the mTOR signaling pathway, a mechanism coincident with that of metformin (MET). Furthermore, our results reveal that BBR exhibits a stronger synergistic effect with SOR compared to MET. These results may contribute to developing innovative combination strategies for the treatment of advanced HCC.

The impact of traditional Chinese medicine and dietary compounds on modulating gut microbiota in hepatic fibrosis: A review

Traditional Chinese medicine (TCM) and dietary compounds have a profound influence on the regulation of gut microbiota (GM) in hepatic fibrosis (HF). Certain substances found in both food and herbs that are edible and medicinal, such as dietary fiber, polyphenols, and polysaccharides, can generate beneficial metabolites like short-chain fatty acids (SCFAs), bile acids (BAs), and tryptophan (Trp). These compounds contribute to regulate the GM, reduce levels of endotoxins in the liver, and alleviate fibrosis and inflammation in the liver. Furthermore, they enhance the composition and functionality of GM, promoting the growth of beneficial bacteria while inhibiting the proliferation of harmful bacteria. These mechanisms mitigate the inflammatory response in the intestines and maintain the integrity of the intestinal barrier. The purpose of this review is to analyze how the GM regulates the pathogenesis of HF, evaluate the regulatory effect of TCM and dietary compounds on the intestinal microflora, with a particular emphasis on modulating flora structure, enhancing gut barrier function, and addressing associated pathogenic factors, thereby provide new insights for the treatment of HF.

Advances in the pharmacological mechanisms of berberine in the treatment of fibrosis

The rising incidence of fibrosis poses a major threat to global public health, and the continuous exploration of natural products for the effective treatment of fibrotic diseases is crucial. Berberine (BBR), an isoquinoline alkaloid, is widely used clinically for its anti-inflammatory, anti-tumor and anti-fibrotic pharmacological effects. Until now, researchers have worked to explore the mechanisms of BBR for the treatment of fibrosis, and multiple studies have found that BBR attenuates fibrosis through different pathways such as TGF-β/Smad, AMPK, Nrf2, PPAR-γ, NF-κB, and Notch/snail axis. This review describes the anti-fibrotic mechanism of BBR and its derivatives, and the safety evaluation and toxicity studies of BBR. This provides important therapeutic clues and strategies for exploring new drugs for the treatment of fibrosis. Nevertheless, more studies, especially clinical studies, are still needed. We believe that with the continuous implementation of high-quality studies, significant progress will be made in the treatment of fibrosis.

Targeting dysregulated intracellular immunometabolism within synovial microenvironment in rheumatoid arthritis with natural products

Immunometabolism has been an emerging hotspot in the fields of tumors, obesity, and atherosclerosis in recent decades, yet few studies have investigated its connection with rheumatoid arthritis (RA). In principle, intracellular metabolic pathways upstream regulated by nutrients and growth factors control the effector functions of immune cells. Dynamic communication and hypermetabolic lesions of immune cells within the inflammatory synovial microenvironment contributes to the development and progression of RA. Hence, targeting metabolic pathways within immune subpopulations and pathological cells may represent novel therapeutic strategies for RA. Natural products constitute a great potential treasury for the research and development of novel drugs targeting RA. Here, we aimed to delineate an atlas of glycolysis, lipid metabolism, amino acid biosynthesis, and nucleotide metabolism in the synovial microenvironment of RA that affect the pathological processes of synovial cells. Meanwhile, therapeutic potentials and pharmacological mechanisms of natural products that are demonstrated to inhibit related key enzymes in the metabolic pathways or reverse the metabolic microenvironment and communication signals were discussed and highlighted.

Berberine ameliorates the progression of primary sclerosing cholangitis by activating farnesoid X receptor

Primary sclerosing cholangitis (PSC) is a rare cholestatic disease characterized by biliary infiltration, hepatic fibrosis and bile duct destruction. To date, treatment options for PSC are very limited. Therefore, the current study is aimed to investigate the therapeutic potential of berberine (BBR) against PSC. The disease was induced by feeding the mice with 3,5-diethoxycarbonyl-1,4-dihydro-2,4,6-collidine (DDC) for four weeks. The serum biochemistry and liver histology were analyzed. Furthermore, the expression of farnesoid X receptor (FXR) was also evaluated by real-time PCR. The results indicated that berberine prevents the progression of PSC by modulating the expression of FXR which ultimately regulates other genes (including Cyp7A1 and BSEP) thus maintaining bile acids homeostasis. Furthermore, the docking analysis showed that berberine interacts with the binding pocket of FXR to activate the protein thus acting as an FXR agonist. In conclusion, data indicate that berberine protects the liver from PSC-related injury. This effect might be due to the modulation of FXR activity.

Systematic screening of hepatoprotective components from traditional Chinese medicine: Zuojin Pill as an example

ETHNOPHARMACOLOGICAL RELEVANCE

Zuojin Pill (ZJP), composed of Coptis chinensis Franch. and Euodia ruticarpa (A. Juss.) Benth. in a mass ratio of 6:1, is a famous traditional Chinese medicine (TCM) formula recorded in "Danxi's Experiential Therapy", an ancient medical book from the Ming Dynasty of China. It is used to treat liver fire invading the stomach, which is caused by liver stagnation transforming into fire and disharmony between the liver and stomach.

AIM OF THE STUDY

To develop a systematic strategy to screen hepatoprotective components from TCM using ZJP as a model sample.

MATERIALS AND METHODS

A CCl4-induced mouse model of acute liver injury was used for the verification of the hepatoprotective effects of ZJP. UPLC-Q-Exactive Plus Orbitrap MS/MS was used for the identification of the components in mouse serum after intragastric administration of ZJP. The hepatoprotective activities of the components found in mouse serum were tested in primary cultured mouse hepatocytes induced by CCl4.

RESULTS

Nine components with significant hepatoprotective activity including berberine, epiberberine, coptisine, palmatine, jatrorrhizine, rutaecarpin, dehydroevodiamine, evocarpine and chlorogenic acid were successfully screened out.

CONCLUSIONS

Our developed strategy has the advantages of high efficiency and low cost, and would provide a powerful tool for screening potential hepatoprotective components from TCM.

The role of PI3k/AKT signaling pathway in attenuating liver fibrosis: a comprehensive review

Excessive accumulation of extracellular matrix (ECM) components within the liver leads to a pathological condition known as liver fibrosis. Alcohol abuse, non-alcoholic fatty liver disease (NAFLD), autoimmune issues, and viral hepatitis cause chronic liver injury. Exploring potential therapeutic targets and understanding the molecular mechanisms involved in liver fibrosis are essential for the development of effective interventions. The goal of this comprehensive review is to explain how the PI3K/AKT signaling pathway contributes to the reduction of liver fibrosis. The potential of this pathway as a therapeutic target is investigated through a summary of results from in vivo and in vitro studies. Studies focusing on PI3K/AKT activation have shown a significant decrease in fibrosis markers and a significant improvement in liver function. The review emphasizes how this pathway may prevent ECM synthesis and hepatic stellate cell (HSC) activation, ultimately reducing the fibrotic response. The specific mechanisms and downstream effectors of the PI3K/AKT pathway in liver fibrosis constitute a rapidly developing field of study. In conclusion, the PI3K/AKT signaling pathway plays a significant role in attenuating liver fibrosis. Its complex role in regulating HSC activation and ECM production, demonstrated both in vitro and in vivo, underscores its potential as a effective therapeutic approach for managing liver fibrosis and slowing disease progression. A comprehensive review of this field provides valuable insights into its future developments and implications for clinical applications.

Berberine prevents NAFLD and HCC by modulating metabolic disorders

Non-alcoholic fatty liver disease (NAFLD) is a global metabolic disease with high prevalence in both adults and children. Importantly, NAFLD is becoming the main cause of hepatocellular carcinoma (HCC). Berberine (BBR), a naturally occurring plant component, has been demonstrated to have advantageous effects on a number of metabolic pathways as well as the ability to kill liver tumor cells by causing cell death and other routes. This permits us to speculate and make assumptions about the value of BBR in the prevention and defense against NAFLD and HCC by a global modulation of metabolic disorders. Herein, we briefly describe the etiology of NAFLD and NAFLD-related HCC, with a particular emphasis on analyzing the potential mechanisms of BBR in the treatment of NAFLD from aspects including increasing insulin sensitivity, controlling the intestinal milieu, and controlling lipid metabolism. We also elucidate the mechanism of BBR in the treatment of HCC. More significantly, we provided a list of clinical studies for BBR in NAFLD. Taking into account our conclusions and perspectives, we can make further progress in the treatment of BBR in NAFLD and NAFLD-related HCC.

Efficacy and underlying mechanisms of berberine against lipid metabolic diseases: a review

Lipid-lowering therapy is an important tool for the treatment of lipid metabolic diseases, which are increasing in prevalence. However, the failure of conventional lipid-lowering drugs to achieve the desired efficacy in some patients, and the side-effects of these drug regimens, highlight the urgent need for novel lipid-lowering drugs. The liver and intestine are important in the production and removal of endogenous and exogenous lipids, respectively, and have an important impact on circulating lipid levels. Elevated circulating lipids predisposes an individual to lipid deposition in the vascular wall, affecting vascular function. Berberine (BBR) modulates liver lipid production and clearance by regulating cellular targets such as cluster of differentiation 36 (CD36), acetyl-CoA carboxylase (ACC), microsomal triglyceride transfer protein (MTTP), scavenger receptor class B type 1 (SR-BI), low-density lipoprotein receptor (LDLR), and ATP-binding cassette transporter A1 (ABCA1). It influences intestinal lipid synthesis and metabolism by modulating gut microbiota composition and metabolism. Finally, BBR maintains vascular function by targeting proteins such as endothelial nitric oxide synthase (eNOS) and lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1). This paper elucidates and summarizes the pharmacological mechanisms of berberine in lipid metabolic diseases from a multi-organ (liver, intestine, and vascular system) and multi-target perspective.

lncRNA Helf promotes hepatic inflammation and fibrosis by interacting with PTBP1 to facilitate PIK3R5 mRNA stabilization

BACKGROUND

Hepatic fibrosis is a common consequence of chronic liver diseases without approved antifibrotic therapies. Long noncoding RNAs (lncRNAs) play an important role in various pathophysiological processes. However, the functions of certain lncRNAs involved in mediating the antifibrotic role remain largely unclear.

METHODS

The RNA level of lnc-High Expressed in Liver Fibrosis (Helf) was detected in both mouse and human fibrotic livers. Furthermore, lnc-Helf-silenced mice were treated with carbon tetrachloride (CCl4) or bile duct ligation (BDL) to investigate the function of lnc-Helf in liver fibrosis.

RESULTS

We found that lnc-Helf has significantly higher expression in human and mouse fibrotic livers as well as M1 polarized hepatic macrophages (HMs) and activated hepatic stellate cells (HSCs). In vivo studies showed that silencing lnc-Helf by AAV8 vector alleviates CCl4- and BDL-induced hepatic inflammation and fibrosis. Furthermore, in vitro experiments revealed that lnc-Helf promotes HSCs activation and proliferation, as well as HMs M1 polarization and proliferation in the absence or presence of cytokine stimulation. Mechanistically, our data illustrated that lnc-Helf interacts with RNA binding protein PTBP1 to promote its interaction with PIK3R5 mRNA, resulting in increased stability and activating the AKT pathway, thus promoting HSCs and HMs activation and proliferation, which augments hepatic inflammation and fibrosis.

CONCLUSION

Our results unveil a lnc-Helf/PTBP1/PIK3R5/AKT feedforward, amplifying signaling that exacerbates the process of hepatic inflammation and fibrosis, thus providing a possible therapeutic strategy for hepatic fibrosis.

Ophiopogonin D ameliorates non‑alcoholic fatty liver disease in high‑fat diet‑induced obese mice by improving lipid metabolism, oxidative stress and inflammatory response

Lipid metabolic disorders, oxidative stress and inflammation in the liver are key steps in the progression of non-alcoholic fatty liver disease (NAFLD). Ophiopogonin D (OP-D), the main active ingredient of Ophiopogon japonicus, exhibits several pharmacological activities such as antioxidant and anti-inflammatory activities. Therefore, the current study aimed to explore the role of OP-D in NAFLD in a high-fat diet (HFD)-induced obesity mouse model. To investigate the effect of OP-D on NAFLD in vivo, a NAFLD mouse model was established following feeding mice with HFD, then the mice were randomly treated with HFD or HFD + OP-D for 4 weeks. Subsequently, primary mouse hepatocytes were isolated, and enzyme-linked immunosorbent assay, reverse transcription-quantitative PCR western blotting and immunofluorescence analysis were used for assessment to explore the direct effect of OP-D in vitro. The results of the present study indicated that OP-D could ameliorate NAFLD in HFD-induced obese mice by regulating lipid metabolism and antioxidant and anti-inflammatory responses. Additionally, OP-D treatment decreased lipogenesis and inflammation levels in vitro, suggesting that the NF-κB signaling pathway may be involved in the beneficial effects of OP-D on NAFLD.

Tissue distribution and integrated pharmacokinetic properties of major effective constituents of oral Gegen-Qinlian decoction in mice

Gegen-Qinlian decoction (GQD) is a classic traditional Chinese medicine (TCM) formula. GQD is effective against colon or liver-related diseases including ulcerative colitis, non-alcoholic fatty liver, and type 2 diabetes. In this study, a liquid chromatography-tandem mass spectrometry method was developed, validated, and then applied to reveal the tissue distribution and integrated pharmacokinetic properties of major effective constituents of oral GQD in mice. The established method was quick, sensitive, and accurate enough to analyze GQD constituents in plasma and tissue homogenate samples quantitatively. According to their concentrations in the portal vein, systemic circulation, liver and colon samples of the mice after oral administration of GQD, the concentration-time curves of the constituents were respectively plotted. The results showed that daidzein, baicalin, and baicalein had relatively high exposure levels in the livers, while puerarin, berberine, epiberberine, coptisine, palmatine, jatrorrhizine, magnoflorine, glycyrrhizic acid, and glycyrrhetinic acid were enriched in the colons. Given that these constituents have significant biological activity, they could be regarded as the major effective constituents of GQD in treating colon or liver-related diseases, respectively. In addition, the integrated pharmacokinetic properties of GQD were studied. The GQD “integrated constituent” reached peak concentration at 4.0 h in the portal vein, the systemic circulation, the livers, and the colons, with half-lives of 1.5–4.1 h and mean retention time of 4.5–6.3 h, respectively. Furthermore, the concentration of the GQD “integrated constituent” in the colons was approximately 10 times higher than that in the livers, both of which were much higher than that in the systemic circulation, indicating its accumulation in these tissues, especially in the colons. In conclusion, the tissue distribution and integrated pharmacokinetic properties of oral GQD were revealed in the study. The results of the tissue distribution study would contribute to identifying the major target tissues and effective constituents of GQD, while the results of the integrated pharmacokinetic study would help to explain the pharmacokinetic properties of oral GQD as a whole.

The short-term effects of berberine in the liver: Narrow margins between benefits and toxicity

Berberine is a plant alkaloid to which antihyperglycemic properties have been attributed. It is also known as an inhibitor of mitochondrial functions. In this work short-term translation of the latter effects on hepatic metabolism were investigated using the isolated perfused rat liver. Once-through perfusion with a buffered saline solution was done. At low portal concentrations berberine modified several metabolic pathways. It inhibited hepatic gluconeogenesis, increased glycolysis, inhibited ammonia detoxification, increased the cytosolic NADH/NAD⁺ ratio and diminished the ATP levels. Respiration of intact mitochondria was impaired as well as the mitochondrial pyruvate carboxylation activity. These results can be regarded as evidence that the direct inhibitory effects of berberine on gluconeogenesis, mediated by both energy metabolism and pyruvate carboxylation inhibition, represent most likely a significant contribution to its clinical efficacy as an antihyperglycemic agent. However, safety concerns also arise because all effects occur at similar concentrations and there is a narrow margin between the expected benefits and toxicity. Even mild inhibition of gluconeogenesis is accompanied by diminutions in oxygen uptake and ammonia detoxification and increases in the NADH/NAD⁺ ratio. All combined, desired and undesired effects could well in the end represent a deleterious combination of events leading to disruption of cellular homeostasis.

An insight into the potential of berberine in animal nutrition: Current knowledge and future perspectives

In animal nutrition, the interest for novel feed additives has expanded with elevating industry standards and consumer awareness besides the demand for healthy animal-derived food products. Consumer and animal health are leading concerns dictating the importance of novel animal feed additives. Berberine (BBR) is a natural pentacyclic isoquinoline alkaloid that has exhibited diverse pharmacological properties, including metabolism-regulating, hepatoprotective, and inflammatory alleviative in addition to its antioxidant activity. Despite detailed information on cellular mechanisms associated with BBR therapeutics, and strong clinical evidence, only a few studies have focused on BBR applied to animal nutrition. However, great pieces of evidence have shown that dietary BBR supplementation could result in improved growth performance, enhanced oxido-inflammatory markers, and mitigated metabolic dysfunctions in both monogastric and ruminant animals. The data discussed in the present review may set the basis for further research on BBR in animal diets for developing novel strategies aiming to improve animal health as well as products with beneficial properties for humans.

Expatiating the Pharmacological and Nanotechnological Aspects of the Alkaloidal Drug Berberine: Current and Future Trends

Traditionally, herbal compounds have been the focus of scientific interest for the last several centuries, and continuous research into their medicinal potential is underway. Berberine (BBR) is an isoquinoline alkaloid extracted from plants that possess a broad array of medicinal properties, including anti-diarrheal, anti-fibrotic, antidiabetic, anti-inflammatory, anti-obesity, antihyperlipidemic, antihypertensive, antiarrhythmic, antidepressant, and anxiolytic effects, and is frequently utilized as a traditional Chinese medicine. BBR promotes metabolisms of glucose and lipids by activating adenosine monophosphate-activated protein kinase, stimulating glycolysis and inhibiting functions of mitochondria; all of these ameliorate type 2 diabetes mellitus. BBR has also been shown to have benefits in congestive heart failure, hypercholesterolemia, atherosclerosis, non-alcoholic fatty liver disease, Alzheimer’s disease, and polycystic ovary syndrome. BBR has been investigated as an interesting pharmacophore with the potential to contribute significantly to the research and development of novel therapeutic medicines for a variety of disorders. Despite its enormous therapeutic promise, the clinical application of this alkaloid was severely limited because of its unpleasant pharmacokinetic characteristics. Poor bioavailability, limited absorption, and poor water solubility are some of the obstacles that restricted its use. Nanotechnology has been suggested as a possible solution to these problems. The present review aims at recent updates on important therapeutic activities of BBR and different types of nanocarriers used for the delivery of BBR in different diseases.

OTUB1 alleviates NASH through inhibition of the TRAF6-ASK1 signaling pathways

BACKGROUND AND AIMS

NAFLD is considered as the hepatic manifestation of the metabolic syndrome, which includes insulin resistance, obesity and hyperlipidemia. NASH is a progressive stage of NAFLD with severe hepatic steatosis, hepatocyte death, inflammation, and fibrosis. Currently, no pharmacological interventions specifically tailored for NASH are approved. Ovarian tumor domain, ubiquitin aldehyde binding 1 (OTUB1), the founding member of deubiquitinases, regulates many metabolism-associated signaling pathways. However, the role of OTUB1 in NASH is unclarified.

METHODS AND RESULTS

We demonstrated that mice with Otub1 deficiency exhibited aggravated high-fat diet-induced and high-fat high-cholesterol (HFHC) diet-induced hyperinsulinemia and liver steatosis. Notably, hepatocyte-specific overexpression of Otub1 markedly alleviated HFHC diet-induced hepatic steatosis, inflammatory responses, and liver fibrosis. Mechanistically, we identified apoptosis signal-regulating kinase 1 (ASK1) as a key candidate target of OTUB1 through RNA-sequencing analysis and immunoblot analysis. Through immunoprecipitation-mass spectrometry analysis, we further found that OTUB1 directly bound to tumor necrosis factor receptor-associated factor 6 (TRAF6) and suppressed its lysine 63-linked polyubiquitination, thus inhibiting the activation of ASK1 and its downstream pathway.

CONCLUSIONS

OTUB1 is a key suppressor of NASH that inhibits polyubiquitinations of TRAF6 and attenuated TRAF6-mediated ASK1 activation. Targeting the OTUB1-TRAF6-ASK1 axis may be a promising therapeutic strategy for NASH.

Therapeutic Effects of Berberine on Liver Fibrosis are associated With Lipid Metabolism and Intestinal Flora

Liver cirrhosis is a form of liver fibrosis resulting from chronic hepatitis caused by various liver diseases, such as viral hepatitis, alcoholic liver damage, nonalcoholic steatohepatitis, autoimmune liver disease, and by parasitic diseases such as schistosomiasis. Liver fibrosis is the common pathological base and precursors of cirrhosis. Inflammation and disorders of lipid metabolism are key drivers in liver fibrosis. Studies have determined that parts of the arachidonic acid pathway, such as its metabolic enzymes and biologically active products, are hallmarks of inflammation, and that aberrant peroxisome proliferator-activated receptor gamma (PPARγ)-mediated regulation causes disorders of lipid metabolism. However, despite the ongoing research focus on delineating the mechanisms of liver fibrosis that underpin various chronic liver diseases, effective clinical treatments have yet to be developed. Berberine (BBR) is an isoquinoline alkaloid with multiple biological activities, such as anti-inflammatory, anti-bacterial, anti-cancer, and anti-hyperlipidemic activities. Many studies have also found that BBR acts via multiple pathways to alleviate liver fibrosis. Furthermore, the absorption of BBR is increased by nitroreductase-containing intestinal flora, and is strengthened via crosstalk with bile acid metabolism. This improves the oral bioavailability of BBR, thereby enhancing its clinical utility. The production of butyrate by intestinal anaerobic bacteria is dramatically increased by BBR, thereby amplifying butyrate-mediated alleviation of liver fibrosis. In this review, we discuss the effects of BBR on liver fibrosis and lipid metabolism, particularly the metabolism of arachidonic acid, and highlight the potential mechanisms by which BBR relieves liver fibrosis through lipid metabolism related and intestinal flora related pathways. We hope that this review will provide insights on the BBR-based treatment of liver cirrhosis and related research in this area, and we encourage further studies that increase the ability of BBR to enhance liver health.

Novel mechanistic insight on the neuroprotective effect of berberine: The role of PPARδ for antioxidant action

Cerebral ischemic stroke ranks the second leading cause of death and the third leading cause of disability in lifetime all around the world, urgently necessitating effective therapeutic interventions. Reactive oxygen species (ROS) have been implicated in stroke pathogenesis and peroxisome proliferator-activated receptors (PPARs) are prominent targets for ROS management. Although recent research has shown antioxidant effect of berberine (BBR), little is known regarding its effect upon ROS-PPARs signaling in stroke. The aim of this study is to explore whether BBR could target on ROS-PPARs pathway to ameliorate middle cerebral artery occlusion (MCAO)-induced stroke. Herein, we report that BBR is able to scavenge ROS in oxidation-damaged C17.2 neural stem cells and stroked mice. PPARδ, rather than PPARα or PPARγ, is involved in the anti-ROS effect of BBR, as evidenced by the siRNA transfection and specific antagonist treatment data. Further, we have found BBR could upregulate NF-E2 related factor-1/2 (NRF1/2) and NAD(P)H:quinone oxidoreductase 1 (NQO1) following a PPARδ-dependent manner. Mechanistic study has revealed that BBR acts as a potent ligand (Kd = 290 ± 92 nM) to activate PPARδ and initiates the transcriptional regulation functions, thus promoting the expression of PPARδ, NRF1, NRF2 and NQO1. Collectively, our results indicate that BBR confers neuroprotective effects by activating PPARδ to scavenge ROS, providing a novel mechanistic insight for the antioxidant action of BBR.

The Traditional Uses, Phytochemistry, Pharmacokinetics, Pharmacology, Toxicity, and Applications of Corydalis saxicola Bunting: A Review

Background:Corydalis saxicola Bunting (CSB) is a perennial herb belonging to genus Corydalis (Papaveraceae), called “Yan-huang-lian” in the Chinese folk. Traditionally, it is used to treat acute conjunctivitis, corneal pannus, acute abdominal pain, hemorrhoidal bleeding, haematochezia, swelling, hepatitis, cirrhosis and liver cancer based on traditional Chinese medicine (TCM) concepts.

Purpose: This review aims to summarize and analyze the pharmacokinetics, pharmacological and toxicological properties of CSB and its extracts; to highlight the relevance of modern pharmacology to traditional pharmacology; also to assess its therapeutic potential.

Methods: CSB related literatures were searched and screened from databases including PubMed, Web of Science and CNKI. The selected literatures provided reliable source identification evidences.

Results: In traditional medicine concepts, CSB has the effects of clearing away heat and detoxification, eliminating dampness, relieving pain, and stopping bleeding. Its modern pharmacology includes hepatoprotective, anticancer, anti-inflammatory, analgesic, antibacterial, anti-oxidative effects. Further, some pharmacological effects support its traditional uses. The CSB total alkaloids (CSBTA) are the main constituents isolated from this plant, and they exert the major of the pharmacological effects. Toxicological studies have shown that the toxicity of CSBTA is mild and reversible in rodents and beagle dogs.

Conclusion: Although the present study summarizes the botany, phytochemistry, pharmacokinetics, pharmacology, toxicity, and applications of this plant, it is still necessary to systemically evaluate the chemistry, safety and parameters related to drug metabolism of the extracts or compounds from this plant before or in clinical trials in the future. Meanwhile, cancers and inflammatory-related diseases may be new research directions of this ethnomedicine.