Epigallocatechin-3-gallate attenuates apoptosis and autophagy in concanavalin A-induced hepatitis by inhibiting BNIP3

Therapeutic potential of oleanolic acid in liver diseases

Liver-associated diseases affect millions of individuals worldwide. In developed countries, the incidence of viral hepatitis is reducing due to advancements in disease prevention, diagnosis, and treatment. However, with improvements in living standards, the prevalence of metabolic liver diseases, such as non-alcoholic fatty liver disease and alcohol-related liver disease, is expected to increase; notably, this rise in the prevalence of metabolic liver disease can lead to the development of more severe liver diseases, including liver failure, cirrhosis, and liver cancer. The growing demand for natural alternative therapies for chronic diseases has highlighted the importance of studying the pharmacology of bioactive compounds in plants. One such compound is oleanolic acid (OA), a pentacyclic triterpenoid known for its antioxidant, anti-inflammatory, anti-ulcer, antibacterial, antiviral, antihypertensive, anti-obesity, anticancer, anti-diabetic, cardioprotective, hepatoprotective, and anti-neurodegenerative properties. Recent studies have demonstrated that OA treatment can reduce the risk of pathological liver damage, ultimately alleviating liver dysregulation and restoring overall liver function. This review aims to explore the latest research on the biological effects of OA and its derivatives. Notably, it explores the mechanisms of action of these compounds in both in vitro and in vivo research models and, ultimately, highlights OA as a promising candidate for alternative therapies in the treatment and management of chronic liver disease.

Enhancing Liver Delivery of Gold Nanoclusters via Human Serum Albumin Encapsulation for Autoimmune Hepatitis Alleviation

Peptide-protected gold nanoclusters (AuNCs), possessing exceptional biocompatibility and remarkable physicochemical properties, have demonstrated intrinsic pharmaceutical activity in immunomodulation, making them a highly attractive frontier in the field of nanomedicine exploration. Autoimmune hepatitis (AIH) is a serious autoimmune liver disease caused by the disruption of immune balance, for which effective treatment options are still lacking. In this study, we initially identified glutathione (GSH)-protected AuNCs as a promising nanodrug candidate for AIH alleviating in a Concanavalin A (Con A)-induced mice model. However, to enhance treatment efficiency, liver-targeted delivery needs to be improved. Therefore, human serum albumin (HSA)-encapsulated AuNCs were constructed to achieve enhanced liver targeting and more potent mitigation of Con A-induced elevations in plasma aspartate transaminase (AST), alanine transaminase (ALT), and liver injury in mice. In vivo and in vitro mechanism studies indicated that AuNCs could suppress the secretion of IFN-γ by Con A-stimulated T cells and subsequently inhibit the activation of the JAK2/STAT1 pathway and eventual hepatocyte apoptosis induced by IFN-γ. These actions ultimately protect the liver from immune cell infiltration and damage caused by Con A. These findings suggest that bio-protected AuNCs hold promise as nanodrugs for AIH therapy, with their liver targeting capabilities and therapeutic efficiency being further improved via rational surface ligand engineering.

Gut Microbiota Participates in Polystyrene Microplastics-Induced Hepatic Injuries by Modulating the Gut-Liver Axis

Dietary pollution by polystyrene microplastics (MPs) can cause hepatic injuries and microbial dysbiosis. Epigallocatechin-3-gallate (EGCG), the major polyphenol in green tea, exerts beneficial effects on the liver by modulating the gut microbiota. However, the role of microbiota in MPs-induced hepatic injuries and the protective effect of EGCG have not been clarified. Here, 5 μm MPs were orally administered to mice to induce hepatic injuries. Subsequently, antibiotic cocktail (ABX) and fecal microbial transplant (FMT) experiments were performed to investigate the underlying microbial mechanisms. Additionally, EGCG was orally administered to mice to explore its protection against MPs-induced hepatic injuries. Our results showed that MPs activated systemic and hepatic inflammation, promoted fibrosis, and altered the liver metabolome; meanwhile, MPs damaged the gut homeostasis by disturbing the gut microbiome, promoting colonic inflammation, and impairing the intestinal barrier. Notably, MPs reduced the abundance of the probiotics Akkermansia, Mucispirillum, and Faecalibaculum while increasing the pathogenic Tuzzerella. Interestingly, the elimination of gut microbiota mitigated MPs-induced colonic inflammation and intestinal barrier impairment. Moreover, ABX ameliorated MPs-induced systemic and hepatic inflammation but not fibrosis. Correspondingly, microbiota from MPs-administered mice induced colonic, systemic, and hepatic inflammation, while their profibrosis effect on the liver was not observed. Finally, EGCG elevated the abundance of probiotics and effectively repressed MPs-induced colonic inflammation. MPs-induced systemic and hepatic inflammation, fibrosis, and remodeling of the liver metabolome were also attenuated by EGCG. These findings illustrated that gut microbiota contributed to MPs-induced colonic and hepatic injuries, while EGCG could serve as a potential prevention strategy for these adverse consequences.

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

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

Salidroside in the Treatment of NAFLD/NASH

Non-alcoholic fatty liver disease (NAFLD) is the commonest reason for chronic liver diseases in the world and is commonly related to the hepatic manifestation of the metabolic syndrome. Non-alcoholic steatohepatitis (NASH) is a deteriorating form of NAFLD, which can eventually develop into fibrosis, cirrhosis, and liver cancer. The reason for NAFLD/NASH development is complicated, such as liver lipid metabolism, oxidative stress, inflammatory response, apoptosis and autophagy, liver fibrosis and gut microbiota. Apart from bariatric surgery and lifestyle changes, officially approved drug therapy for NAFLD/NASH treatment is lacking. Salidroside (SDS) is a phenolic compound extensively distributed in the tubers of Rhodiola plants, which possesses many significant biological activities. This review summarized the related targets regulated by SDS in treating NAFLD/NASH. It is indicated that SDS could improve the status of NAFLD/NASH by ameliorating abnormal lipid metabolism, inhibiting oxidative stress, regulating apoptosis and autophagy, reducing inflammatory response, alleviating fibrosis and regulating gut microbiota. In conclusion, although the multiple bioactivities of SDS have been confirmed, the clinical data are inadequate and need to become the focus of attention in the later study.

Dietary Polyphenols Alleviate Autoimmune Liver Disease by Mediating the Intestinal Microenvironment: Challenges and Hopes

Autoimmune liver disease is a chronic liver disease caused by an overactive immune response in the liver that imposes a significant health and economic cost on society. Due to the side effects of existing medicinal medications, there is a trend toward seeking natural bioactive compounds as dietary supplements. Currently, dietary polyphenols have been proven to have the ability to mediate gut-liver immunity and control autoimmune liver disease through modulating the intestinal microenvironment. Based on the preceding, this Review covers the many forms of autoimmune liver illnesses, their pathophysiology, and the modulatory effects of polyphenols on immune disorders. Finally, we focus on how polyphenols interact with the intestinal milieu to improve autoimmune liver disease. In conclusion, we suggest that dietary polyphenols have the potential as gut-targeted modulators for the prevention and treatment of autoimmune liver disease and highlight new perspectives and critical issues for future pharmacological applications.

Epigallocatechin‑3‑gallate hinders metabolic coupling to suppress colorectal cancer malignancy through targeting aerobic glycolysis in cancer‑associated fibroblasts

In recent times, researchers working on tumor metabolism have paid increasing attention to the tumor microenvironment. Emerging evidence has confirmed that epigenetic modifications of cancer-associated fibroblasts (CAFs) alters the characteristics of glucose metabolism to achieve a symbiotic relationship with the cancer cells. Epigallocatechin-3-gallate (EGCG) exerts anti-tumor effects via a variety of mechanisms, although the underlying mechanism that accounts for the effects of EGCG on glucose metabolic alterations of CAFs have yet to be elucidated. In the present study, through co-culture with colorectal cancer (CRC) cells, human intestinal fibroblasts were transformed into CAFs, and exhibited enhanced aerobic glycolysis. Induced CAFs were able to enhance the proliferation, migration and invasion of CRC cells in vitro. EGCG treatment led to direct inhibition of the proliferation and migration of CRC cells; furthermore, EGCG treatment of CAFs suppressed their tumor-promoting capabilities by inhibiting their glycolytic activity. Blocking the lactic acid efflux of CAFs with a monocarboxylate transporter 4 (MCT4) inhibitor or through silencing MCT4 could also suppress their tumor-promoting capabilities, indicating that lactate fulfills an important role in the metabolic coupling that occurs between CAFs and cancer cells. Taken together, the results of the present study showed that EGCG targeting of the metabolism of tumor stromal cells provided a safe and effective strategy of anti-cancer therapy.

Synthesis and biological evaluation of novel schisanhenol derivatives as potential hepatoprotective agents

Twenty-one new schisanhenol derivatives were synthesized, and their hepatoprotective effects against liver injury induced by concanavalin A (Con A) were evaluated in vitro using an MTT assay. The data indicated that most derivatives exhibited equivalent or better protective activity than the positive control (dimethyl dicarboxylate biphenyl, DDB) under the same conditions. Among them, compound 1b showed the most potent hepatoprotective activity against Con A-induced immunological injury. Mechanistic studies in vitro revealed that 1b inhibited cell apoptosis and inflammatory responses caused by Con A treatment via IL-6/JAK2/STAT3 signaling pathway. Consistently, it also exhibited significant hepatoprotective activity in mice with Con A-induced immunological liver injury. These results clearly indicated that 1b might be a highly potent hepatoprotective agent targeting IL-6/STAT3 signaling pathway.

Lactate-related metabolic reprogramming and immune regulation in colorectal cancer

Changes in cellular metabolism involving fuel sources are well-known mechanisms of cancer cell differentiation in the context of carcinogenesis. Metabolic reprogramming is regulated by oncogenic signaling and transcriptional networks and has been identified as an essential component of malignant transformation. Hypoxic and acidified tumor microenvironment contributes mainly to the production of glycolytic products known as lactate. Mounting evidence suggests that lactate in the tumor microenvironment of colorectal cancer(CRC) contributes to cancer therapeutic resistance and metastasis. The contents related to the regulatory effects of lactate on metabolism, immune response, and intercellular communication in the tumor microenvironment of CRC are also constantly updated. Here we summarize the latest studies about the pleiotropic effects of lactate in CRC and the clinical value of targeting lactate metabolism as treatment. Different effects of lactate on various immune cell types, microenvironment characteristics, and pathophysiological processes have also emerged. Potential specific therapeutic targeting of CRC lactate metabolism is also discussed. With increased knowledge, effective druggable targets might be identified, with the aim of improving treatment outcomes by reducing chemoresistance.

Pathogenesis of Concanavalin A induced autoimmune hepatitis in mice

Autoimmune hepatitis (AIH) is an autoimmune disease characterized by liver parenchymal destruction and chronic fibrosis. Its exact etiology and pathogenesis are not yet fully understood.(Please connect with the following, do not leave a line) Concanavalin A (Con A)-induced mice hepatitis model is a liver injury mediated by T cell and macrophage activation, and its pathogenesis and pathological changes are similar to human AIH. The establishment of this model has greatly promoted the research progress of AIH pathogenesis. However, the exact mechanism of Con A induced liver injury in mice, and its possible defects or deficiencies, has not yet been described in a clear and detailed manner. Therefore, the model has some limitations when applied to the study of the pathogenesis and treatment mechanism of AIH. This article reveals the pathogenesis of Con A induced liver injury in mice from the aspects of immune disorder and coagulation mechanism, expounds the significance of non-coding RNA in this model, summarizes the signal transduction pathways involved in this model, and summarizes the advantages and disadvantages of the model, which provides a theoretical basis and research target for the application of Con A induced liver injury model in AIH in the future.

Nimbolide attenuated the inflammation in the liver of autoimmune hepatitis's mice through regulation of HDAC3

A chronic liver disease named autoimmune hepatitis (AIH) will carry elevated levels of inflammatory cytokines, but there is currently no effective treatment to cure it. Histone deacetylase 3 (HDAC3) takes an important position in regulating the expression of inflammatory genes. Nimbolide (NIB) is a limonoid extracted from the neem tree (Azadirachta indica) that has been found to be effective against many diseases, including cancer, scleroderma, and acute respiratory distress syndrome. Here, we investigated the protective effect of nimbolide on AIH liver. Mice and AML12 cells were employed to establish AIH model with liver antigen S100 and cell injury model of LPS, and then treated with different concentrations of nimbolide. After the successful establishment of the animal model and cell model, inflammatory cytokines of IL-1β, IL-6 and TNF-α as well as cellular signaling related to inflammation such as STAT3, IκB-α and NF-κB were examined. We observed for the first time about nimbolide can effectively inhibit inflammation in AIH mice's liver and AML12 cells by inhibiting HDAC3 expression. HDAC3 knocked down by siRNA in cells can also effectively alleviate the inflammation in AML12 cells, further confirming that HDAC3 plays an important role in the inflammation of liver cells. These results suggest nimbolide could be a potential new treatment for autoimmune hepatitis, and HDAC3 may become a new target for autoimmune hepatitis.

Nrf2 signalling pathway and autophagy impact on the preventive effect of green tea extract against alcohol-induced liver injury

OBJECTIVES

To explore the potential molecular mechanism underlying the effect of green tea extract (TE), rich in tea polyphenols (TPs), on improving alcohol-induced liver injury.

METHODS

Mice were intragastrically treated with 50% (v/v) alcohol administration (15 ml/kg BW) with or without three doses of TE (50, 120 and 300 mg TPs/kg BW) daily for 4 weeks, and biological changes were tested.

KEY FINDINGS

The TE improved the functional and histological situations in the liver of the mice accepted alcohol administration, including enzymes for alcohol metabolism, oxidative stress and lipid accumulation. Interestingly, the TE increased the nuclear translocation of nuclear factor erythroid-2-related factor 2 (Nrf2), with the decreasing expression of kelch-like ECH-associated protein 1 (Keap1), indicating the association between the effect of TE with Nrf2-mediated antioxidant signalling. Moreover, the TE restored the activity of autophagy, showing as lifted Beclin-1 expression, LC3B-II/LC3B-I ratio, and decreased p62 expression. Importantly, all these effects were dose-dependent.

CONCLUSIONS

These findings provide a new notion for the first time that the TE preventing against alcohol-induced liver injury is closely related to accelerated metabolism of alcohol and relieved oxidative stress, which is associated with Nrf2 signalling activation and autophagy restoration, thus the reduction of lipid accumulation in liver.

The Role of Epigallocatechin-3-Gallate in Autophagy and Endoplasmic Reticulum Stress (ERS)-Induced Apoptosis of Human Diseases

Tea containing abundant catechins is a popular non-alcoholic beverage worldwide. Epigallocatechin-3-gallate (EGCG) is the predominately active substance in catechins, exhibiting a wide range of functional properties including cancer suppression, neuroprotective, metabolic regulation, cardiovascular protection, stress adjustment, and antioxidant in various diseases. Autophagy, a basic cell function, participates in various physiological processes which include clearing away abnormally folded proteins and damaged organelles, and regulating growth. EGCG not only regulates autophagy via increasing Beclin-1 expression and reactive oxygen species generation, but also causing LC3 transition and decreasing p62 expression. EGCG-induced autophagy is involved in the occurrence and development of many human diseases, including cancer, neurological diseases, diabetes, cardiovascular diseases, and injury. Apoptosis is a common cell function in biology and is induced by endoplasmic reticulum stress (ERS) as a cellular stress response which is caused by various internal and external factors. ERS-induced apoptosis of EGCG influences cell survival and death in various diseases via regulating IRE1, ATF6, and PERK signaling pathways, and activating GRP78 and caspase proteins. The present manuscript reviews that the effect of EGCG in autophagy and ERS-induced apoptosis of human diseases.

Magnesium isoglycyrrhizinate ameliorates concanavalin A-induced liver injury via the p38 and JNK MAPK pathway

CONTEXT

Acute liver failure is a serious disease caused by a variety of factors, and immunological injury is an important pathological process. Comprehensive liver treatment efficacy is poor, and the mortality rate is high. Magnesium isoglycyrrhizinate (MgIG) is a new glycyrrhizin drug extracted from the traditional Chinese medicine licorice. The mechanism by which MgIG regulates ConcanavalinA (ConA)-induced immunological liver injury in mice is not completely clear.

MATERIALS AND METHODS

Immunological liver injury was induced in mice by ConA injection, and the inflammatory macrophages model was induced by lipopolysaccharide (LPS). MgIG was administered 30 min prior to ConA and LPS treatment. The mice in the different groups were sacrificed 12 h after treatment, and macrophages were measured at 30 min, 1 h, and 2 h after induction. Macrophages, liver, and blood samples were then collected for analysis.

RESULTS

After drug administration, the MgIG group showed a marked decrease in serum transaminase levels, reduced apoptosis and hepatic inflammatory responses compared to the ConA group. Furthermore, there was a significant reduction in inflammatory cytokine levels in the serum and liver tissue. In vitro, the expression of inflammatory cytokines was distinctly reduced after MgIG administration. In addition, MgIG pretreatment reduced the expression of inflammatory cytokines and regulated the phosphorylation of p38 and JNK proteins in the MAPK pathway.

CONCLUSION

These findings demonstrated that MgIG protects against ConA-induced immunological liver injury by markedly alleviating liver inflammation, and this provides guidance for the clinical amelioration of liver inflammation induced by immunological factors.

Kupffer cell depletion attenuates IL-6/STAT3 mediates hepatocyte apoptosis in immunological liver injury of trichloroethylene sensitized mice

Trichloroethylene (TCE) induced TCE hypersensitivity syndrome which makes immune injuries in multi-system. The multiple organ damage included skin, liver, kidney and so on. The main manifestations of liver injuries were apoptosis and edema of hepatocytes. In our previous research, we found the activation of Kupffer cells (KCs) which increased IL-6 can aggravate liver cell apoptosis in TCE sensitized mice. However, the mechanism of IL-6 in liver damages induced by TCE was not clear. This study explored the function of IL-6/STAT3 signal pathway on the TCE induced apoptosis of liver cell. We established a TCE sensitized BALB/c mouse model with a KCs inhibitor GdCl₃, we found that the expressions of ALT and AST in TCE sensitization positive mice were higher than other mice, and the expressions of apoptosis-related proteins were up-regulated in TCE sensitization positive mice, GdCl₃ could alleviate this process. Meanwhile, GdCl₃ could significantly decrease the expressions of IL-6/STAT3 proteins. All in all, the activation of KCs can increase the expression of IL-6, IL-6R and phosphorylate STAT3, induces hepatocyte apoptosis, and participates in immunity damage of liver which induced by TCE.

Montelukast ameliorates Concanavalin A-induced autoimmune hepatitis in mice via inhibiting TNF-α/JNK signaling pathway

BACKGROUND

Concanavalin A (ConA) is a well-established model to induce autoimmune hepatitis (AIH) in mice which mimics pathological alterations that occur in human. The pathogenesis of ConA-induced AIH involves many signaling pathways. Montelukast is a leukotriene receptor antagonist that is mainly used in the management of asthma. The antioxidant, anti-inflammatory and anti-apoptotic effects of montelukast have been reported in previous studies. Lately, montelukast has been documented to confer protection against various inflammatory diseases. Up to date, no study has explored the effect of montelukast on AIH induced by ConA.

AIM AND METHOD

This study aims to detect the protective effects of montelukast (10 mg/kg) on ConA (20 mg/kg)- induced AIH in mice and to demonstrate its hepatoprotective mechanisms. Hepatic function, histological changes, oxidative stress, inflammation, autophagy, and apoptotic markers were investigated.

RESULTS

Hepatic function and histological data revealed that treatment with montelukast significantly attenuated ConA-induced hepatic damage. Montelukast significantly reduced JNK level and NFκB p65 expression, and inhibited proinflammatory cytokines (TNF-α and IL-6) as well as oxidative stress (MDA, NO, and GSH). Moreover, inflammatory cells (CD4+ infiltration and the levels of apoptotic markers (Bax and caspase-3) besides autophagy biomarkers (Beclin1 and LC3) were reduced.

CONCLUSION

Our results suggest that montelukast could be a potential therapeutic drug against the ConA-induced AIH through its anti-oxidant, anti-inflammatory, anti- autophagy as well as anti-apoptotic properties.

Total glucosides of paeony decreases apoptosis of hepatocytes and inhibits maturation of dendritic cells in autoimmune hepatitis

Total glucosides of paeony (TGP), an active mixture extracted from paeony root, has anti-inflammatory and immunoregulatory effects and is widely used for the treatment of autoimmune diseases such as rheumatoid arthritis. However, the role of TGP in autoimmune hepatitis (AIH) is still unknown. In this study, we aimed to investigate the effect of TGP in autoimmune liver disease (AILD) patients and in concanavalin A (Con A)-induced experimental autoimmune hepatitis (EAH). Changes in biochemical parameters of AILD patients showed that treatment with TGP exerts significant protective effects on liver function, as reflected by decreased levels of serum alanine transaminase, aspartate transaminase, γ-glutamyl transpeptidase and total bilirubin. In EAH mice, we found that pretreatment with TGP reduced the levels of serum liver enzyme levels, histopathological damage and hepatocyte apoptosis. Importantly, flow cytometry analysis showed that pretreatment with TGP reduced the infiltration of mature dendritic cells in the liver. In vitro, TGP pretreatment ameliorated the Con A-induced mitochondrial membrane potential decline, reactive oxygen species increase, and apoptosis increase in hepatocytes. In addition, the levels of Bax, Cleaved Caspase-3 and cytoplasmic Cytochrome C decreased during this process, whereas those of Bcl-2 and mitochondrial Cytochrome C increased. Therefore, TGP might decrease hepatocyte apoptosis through the mitochondrial apoptotic pathway. Moreover, the maturation of bone marrow dendritic cells was also inhibited by TGP treatment. In conclusion, TGP treatment ameliorates AIH by regulating hepatocyte apoptosis and DC maturation. TGP is a potential compound for AIH treatment.

Methylprednisolone Decreases Mitochondria-Mediated Apoptosis and Autophagy Dysfunction in Hepatocytes of Experimental Autoimmune Hepatitis Model via the Akt/mTOR Signaling

Autoimmune hepatitis (AIH) is characterized by massive immune cell-mediated hepatocyte destruction. Glucocorticoids, particularly methylprednisolone (MP), are the most effective treatment for AIH; however, the mechanism underlying the effects of glucocorticoid treatment has not been fully elucidated. The present study explored the effects of MP on damaged hepatocytes in mice with concanavalin A (ConA)-induced experimental autoimmune hepatitis (EAH). C57BL/6 mice were divided into three groups: a normal control group (injected with normal saline), a ConA (20 mg/kg) group, and a ConA + MP (3.12 mg/kg) group. The serum levels of liver enzymes, cytokines, activated T cells, and apoptosis- and autophagy-associated marker proteins were determined 12 h after ConA injection. Human hepatocyte cell line LO2 was used to verify the effects of ConA and MP in vitro. MP treatment significantly decreased inflammatory reactions in the serum and liver tissues and activated the Akt/mTOR signaling pathway to inhibit apoptosis and autophagy in hepatocytes in vivo. Transmission electron microscopy (TEM) revealed fewer autophagosomes in the MP-treated group than in the ConA-treated group. MP treatment obviously suppressed apoptosis and mitochondrial membrane potential (ΔΨm) loss in hepatocytes in vitro. Furthermore, ConA treatment increased the levels of LC3-II, p62/SQSTM1, and Beclin-1, while bafilomycin A1 did not augment the levels of LC3-II. MP treatment decreased the levels of LC3-II, p62/SQSTM1, and Beclin-1 and upregulated the levels of phosphorylated (p)-Akt and p-mTOR. In conclusion, MP ameliorated mitochondria-mediated apoptosis and autophagy dysfunction in ConA-induced hepatocyte injury in vivo and in vitro via the Akt/mTOR signaling pathway.

Opportunities and challenges of co-targeting epidermal growth factor receptor and autophagy signaling in non-small cell lung cancer

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are a standard therapy for patients with non-small cell lung cancer (NSCLC) with sensitive mutations. However, acquired resistance emerges following a median of 6-12 months. Several studies demonstrated that EGFR-TKI-induced tumor microenvironment stresses and autophagy are important causes of resistance. The current review summarizes the molecular mechanisms involved in EGFR-mediated regulation of autophagy. The role of autophagy in EGFR-TKI treatment, which may serve a role in protection or cell death, was discussed. Furthermore, co-inhibiting EGFR and autophagy signaling as a rational therapeutic strategy in the treatment of patients with NSCLC was explored.

Modulation of Autophagy for Controlling Immunity

Autophagy is an essential process that maintains physiological homeostasis by promoting the transfer of cytoplasmic constituents to autophagolysosomes for degradation. In immune cells, the autophagy pathway plays an additional role in facilitating proper immunological functions. Specifically, the autophagy pathway can participate in controlling key steps in innate and adaptive immunity. Accordingly, alterations in autophagy have been linked to inflammatory diseases and defective immune responses against pathogens. In this review, we discuss the various roles of autophagy signaling in coordinating immune responses and how these activities are connected to pathological conditions. We highlight the therapeutic potential of autophagy modulators that can impact immune responses and the mechanisms of action responsible.

Autophagy in Human Health and Disease: Novel Therapeutic Opportunities

SIGNIFICANCE

In eukaryotes, autophagy represents a highly evolutionary conserved process, through which macromolecules and cytoplasmic material are degraded into lysosomes and recycled for biosynthetic or energetic purposes. Dysfunction of the autophagic process has been associated with the onset and development of many human chronic pathologies, such as cardiovascular, metabolic, and neurodegenerative diseases as well as cancer. Recent Advances: Currently, comprehensive research is being carried out to discover new therapeutic agents that are able to modulate the autophagic process in vivo. Recent evidence has shown that a large number of natural bioactive compounds are involved in the regulation of autophagy by modulating several transcriptional factors and signaling pathways.

CRITICAL ISSUES

Critical issues that deserve particular attention are the inadequate understanding of the complex role of autophagy in disease pathogenesis, the limited availability of therapeutic drugs, and the lack of clinical trials. In this context, the effects that natural bioactive compounds exert on autophagic modulation should be clearly highlighted, since they depend on the type and stage of the pathological conditions of diseases.

FUTURE DIRECTIONS

Research efforts should now focus on understanding the survival-supporting and death-promoting roles of autophagy, how natural compounds interact exactly with the autophagic targets so as to induce or inhibit autophagy and on the evaluation of their pharmacological effects in a more in-depth and mechanistic way. In addition, clinical studies on autophagy-inducing natural products are strongly encouraged, also to highlight some fundamental aspects, such as the dose, the duration, and the possible synergistic action of these compounds with conventional therapy.

Human liver stem cells attenuate concanavalin A-induced acute liver injury by modulating myeloid-derived suppressor cells and CD4+ T cells in mice

BACKGROUND

Acute liver failure (ALF) is a serious threat to the life of people all over the world. Finding an effective way to manage ALF is important. Human liver stem cells (HLSCs) are early undifferentiated cells that have been implicated in the regeneration and functional reconstruction of the liver. In this study, we aimed to evaluate the protective effects of the HLSC line HYX1 against concanavalin A (ConA)-induced acute liver injury.

METHODS

HYX1 cells were characterized by microscopy, functional assays, gene expression, and western blot analyses. We showed that HYX1 cells can differentiate into hepatocytes. We intraperitoneally injected HYX1 cells in mice and administered ConA via caudal vein injection 3, 6, 12, 24, and 48 h later. The effects of HYX1 cell transplantation were evaluated through blood tests, histology, and flow cytometry.

RESULTS

HYX1 cells reduced the levels of alanine transaminase (ALT), aspartate aminotransferase (AST), and total bilirubin (TBIL) in serum and dramatically decreased the severity of liver injuries. Mechanistically, HYX1 cells promoted myeloid-derived suppressor cell (MDSC) migration into the spleen and liver, while reducing CD4⁺ T cell levels in both tissues. In addition, HYX1 cells suppressed the secretion of proinflammatory cytokines, such as tumour necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), but led to increased interleukin-10 (IL-10) production.

CONCLUSIONS

These results confirm the efficacy of HLSCs in the prevention of the ConA-induced acute liver injury through modulation of MDSCs and CD4⁺ T cell migration and cytokine secretion.

The Protective Effects of Levo-Tetrahydropalmatine on ConA-Induced Liver Injury Are via TRAF6/JNK Signaling

Aims

Levo-tetrahydropalmatine (L-THP) is an active ingredient of Corydalis yanhusuo W. T. Wang, which has many bioactive properties. Herein, we investigated the protective effects of L-THP on concanavalin A- (ConA-) induced hepatitis in mice and explored its possible mechanisms of these effects.

Main Methods

Balb/c mice were intravenously injected with 25 mg/kg ConA to generate a model of acute autoimmune hepatitis, and L-THP (20 or 40 mg/kg) was administered orally once daily for 5 d before the ConA injection. The liver enzyme levels, proinflammatory cytokine levels, and other marker protein levels were determined 2, 8, and 24 h after ConA injection.

Results

L-THP could decrease serum liver enzymes and pathological damage by reducing the release of inflammatory factors like IL-6 and TNF-α. The results of Western Blot and PCR indicated that L-THP could ameliorate liver cell apoptosis and autophagy. L-THP could suppress T lymphocyte proliferation and the production of TNF-α and IL-6 induced by ConA in a dose-dependent manner in vitro. Additionally, the protective functions of L-THP depended on downregulating TRAF6/JNK signaling. Conclusion. The present study indicated that L-THP attenuated acute liver injury in ConA-induced autoimmune hepatitis by inhibiting apoptosis and autophagy via the TRAF6/JNK pathway.

Dysregulation of Sqstm1, mitophagy, and apoptotic genes in chronic exposure to arsenic and high-fat diet (HFD)

Arsenic (As) is a toxic and hazardous metalloid. Unfortunately, its presence in drinking water together with wrong nutritional patterns is associated with an increase in the occurrence of metabolic disorders in young people. Degradation of mitochondria is presented by a specific form of autophagy called mitophagy which is an important landmark leading to apoptosis during lipotoxicity. Lipotoxicity and cellular toxicity due to arsenic intake can lead to changes in mitophagy and apoptosis. The protein derived from SQSTM1 gene, also called p62, plays an important role in energy homeostasis in the liver, and it can contribute to the regulation of autophagic responses given its effect on signaling of mTOR, MAPK, and NF-KB. Consequently, changes in Sqstm1, mitophagy (BNIP3), and apoptotic (caspase 3) genes in the livers of NMRI mice were examined with the use of real-time RT-PCR Array followed by exposure to an environmentally relevant and negligible cytotoxic concentration of arsenite (50 ppm) in drinking water while being fed with a high-fat diet (HFD) or low-fat diet (LFD) for 20 weeks (LFD-As and HFD-As groups). While LFD-As and HFD groups showed a decrease in BNIP3 expression, a significant increase was observed in the HFD-As group. P62 gene showed downregulation in LFD-As and HFD groups, and upregeneration was observed in the HFD-As group. Caspase 3 showed increased expression as the key factor associated with apoptotic liver cell death in the three groups, with the highest value in HFD-As group. Overall, the changes observed in the expression of Sqstm1, BNIP3, and caspase 3 in this study can be related to the level of liver damage caused by exposure to arsenic and HFD and probably, BNIP3 pro-apoptotic protein is associated with an increased cell death due to HFD and As.

Quantitative Proteomic Analysis Reveals That Arctigenin Alleviates Concanavalin A-Induced Hepatitis Through Suppressing Immune System and Regulating Autophagy

Concanavalin A-induced autoimmune hepatitis is a well-established experimental model for immune-mediated liver injury. It has been widely used in the therapeutic studies of immune hepatitis. The in-depth analysis of dysregulated proteins from comparative proteomic results indicated that the activation of immune system resulted in the deregulation of autophagy. Follow-up studies validated that some immune related proteins, including Stat1, Pkr, Atg7, and Adrm1, were indeed upregulated. The accumulations of LC3B-II and p62 were confirmed by immunohistochemistry and Western blot analyses. Arctigenin pretreatment significantly alleviated the liver injury, as evidenced by biochemical and histopathological investigations, whose protective effects were comparable with Prednisone acetate and Cyclosporin A. Arctigenin pretreatment decreased the levels of IL-6 and IFN-γ, but increased the ones of IL-10. Next, the quantitative proteomic analysis demonstrated that ARC pretreatment suppressed the activation of immune system through the inhibition of IFN-γ signaling, when it downregulated the protein expressions of Stat1, P-Stat1, Pkr, P-Pkr, Bnip3, Beclin1, Atg7, LC3B, Adrm1, and p62. Meanwhile, Arctigenin pretreatment also reduced the gene expressions of Stat1, Pkr, and Atg7. These results suggested that Arctigenin alleviated autophagy as well as apoptosis through inhibiting IFN-γ/IL-6/Stat1 pathway and IL-6/Bnip3 pathway. In summary, the comparative proteomic analysis revealed that the activation of immune system led to Concanavalin A-induced hepatitis. Both autophagy and apoptosis had important clinical implications for the treatment of immune hepatitis. Arctigenin might exert great therapeutic potential in immune-mediated liver injury.

Fucosterol Protects against Concanavalin A-Induced Acute Liver Injury: Focus on P38 MAPK/NF-κB Pathway Activity

Objective

Fucosterol is derived from the brown alga Eisenia bicyclis and has various biological activities, including antioxidant, anticancer, and antidiabetic properties. The aim of this study was to investigate the protective effects of fucosterol pretreatment on Concanavalin A- (ConA-) induced acute liver injury in mice, and to understand its molecular mechanisms.

Materials and Methods

Acute liver injury was induced in BALB/c mice by ConA (25 mg/kg), and fucosterol (dissolved in 2% DMSO) was orally administered daily at doses of 25, 50, and 100 mg/kg. The levels of hepatic necrosis, apoptosis, and autophagy associated with inflammatory cytokines were measured at 2, 8, and 24 h.

Results

Fucosterol attenuated serum liver enzyme levels and hepatic necrosis and apoptosis induced by TNF-α, IL-6, and IL-1β. Fucosterol also inhibited apoptosis and autophagy by upregulating Bcl-2, which decreased levels of functional Bax and Beclin-1. Furthermore, reduced P38 MAPK and NF-κB signaling were accompanied by PPARγ activation.

Conclusion

This study showed that fucosterol could alleviate acute liver injury induced by ConA by inhibiting P38 MAPK/PPARγ/NF-κB signaling. These findings highlight that fucosterol is a promising potential therapeutic agent for acute liver injury.

Isorhamnetin: A hepatoprotective flavonoid inhibits apoptosis and autophagy via P38/PPAR-α pathway in mice

Isorhamnetin, a flavonoid compound extracted from plants' fruit or leaves, like sea buckthorn (Hippophae rhamnoides L.), has many biological functions, including anti-tumor, anti-oxidant and anti-inflammatory effect. The present study is in order to explore the hepatoprotective effect of isorhamnetin on concanavalin A (ConA)-induced acute fulminant hepatitis and the underlying mechanism. Mice were injected with ConA (25 mg/kg) to induce acute fulminant hepatitis, three doses of isorhamnetin (10/30/90 mg/kg) was intraperitoneally administrated about 1 h previously. The serum and liver tissues were harvested at 2, 8, and 24 h after ConA injection. The levels of serum liver enzymes and proinflammatory cytokines were significantly reduced in isorhamnetin administration groups. Besides, isorhamnetin improved pathological damage. Furthermore, isorhamnetin affected P38/PPAR-α pathway, and subsequently regulated the expression of apoptosis and autophagy related proteins. The present study investigated that isorhamnetin inhibits apoptosis and autophagy via P38/PPAR-α pathway in mice.

Salidroside mediates apoptosis and autophagy inhibition in concanavalin A-induced liver injury

Salidroside (Sal) is a glycoside extract from Rhodiola rosea L. with anti-inflammatory, antioxidant, anticancer and cardioprotective properties. The present study explored the protective effects and the possible mechanisms of Sal on concanavalin A (ConA)-induced liver injury in mice. Balb/C mice were divided into five groups: Normal control (injected with normal saline), ConA (25 mg/kg), Sal (10 mg/kg) +ConA, Sal (20 mg/kg) + ConA (Sal injected 2 h prior to ConA injection) and Sal (20 mg/kg) only. The serum levels of liver enzymes, pro-inflammatory cytokines, and apoptosis- and autophagy-associated marker proteins were determined at 2, 8 and 24 h after ConA injection. LY294002 was further used to verify whether the phosphoinositide 3-kinase (PI3K)/Akt pathway was activated. Primary hepatocytes were isolated to verify the effect of Sal in vitro. The results indicated that Sal was a safe agent to reduce pathological damage and serum liver enzymes in ConA-induced liver injury. Sal suppressed inflammatory reactions in serum and liver tissues, and activated the PI3K/Akt signaling pathway to inhibit apoptosis and autophagy in vivo and in vitro, which could be reversed by LY294002. In conclusion, Sal attenuated ConA-induced liver injury by modulating PI3K/Akt pathway-mediated apoptosis and autophagy in mice.

The Hepatoprotection by Oleanolic Acid Preconditioning: Focusing on PPARα Activation

Objective

Previous studies have characterized the hepatoprotective and anti-inflammatory properties of oleanolic acid (OA). This study aimed to investigate the molecular mechanisms of OA hepatoprotection in concanavalin A- (ConA-) induced acute liver injury.

Materials and Methods

ConA (20 mg/kg) was intravenously injected to induce acute liver injury in Balb/C mice. OA pretreatment (20, 40, and 80 mg/kg) was administered subcutaneously once daily for 3 consecutive days prior to treatment with ConA; 2, 8, and 24 h after ConA injection, the levels of serum liver enzymes and the histopathology of major factors and inflammatory cytokines were determined.

Results

OA reduced the release of serum liver enzymes and inflammatory factors and prevented ConA mediated damage to the liver. OA elevated the expression levels of peroxisome proliferator-activated receptor alpha (PPARα) and decreased the phosphorylation of c-Jun NH2-terminal kinase (JNK).

Conclusion

OA exhibits anti-inflammatory properties during ConA-induced acute liver injury by attenuating apoptosis and autophagy through activation of PPARα and downregulation of JNK signaling.

Epistructured catechins, EGCG and EC facilitate apoptosis induction through targeting de novo lipogenesis pathway in HepG2 cells

Background

Abnormally high expression of the mammalian de novo lipogenesis (DNL) pathway in various cancer cells promotes cell over-proliferation and resistance to apoptosis. Inhibition of key enzymes in the DNL pathway, namely, ATP citrate lyase, acetyl-CoA carboxylase, and fatty acid synthase (FASN) can increase apoptosis without cytotoxicity to non-cancerous cells, leading to the search for and presentation of novel selective and powerful targets for cancer therapy. Previous studies reported that epistructured catechins, epigallocatechin gallate (EGCG) and epicatechin (EC) exhibit different mechanisms regarding a strong inducer of apoptosis in various cancer cell lines. Thus, the current study investigated the growth inhibitory effect of EGCG and EC, on the enzyme expression and activity of the DNL pathway, which leads to the prominent activity of carnitine palmitoyl transferase-1 (CPT-1) mediating apoptosis in HepG2 cells.

Methods

The cytotoxicity on HepG2 cells of EGCG and EC was determined by MTT assay. Cell death caused by apoptosis, the dissipation of mitochondrial membrane potential (MMP), and cell cycle arrest were then detected by flow cytometry. We further investigated the decrease of fatty acid levels associated with DNL retardation, followed by evaluation of DNL protein expression. Then, the negative inhibitory effect of depleted fatty acid synthesis on malonyl-CoA synthesis followed by regulating of CPT-1 activity was investigated. Thereafter, we inspected the enhanced reactive oxygen species (ROS) generation, which is recognized as one of the causes of apoptosis in HepG2 cells.

Results

We found that EGCG and EC decreased cancer cell viability by increasing apoptosis as well as causing cell cycle arrest in HepG2 cells. Apoptosis was associated with MMP dissipation. Herein, EGCG and EC inhibited the expression of FASN enzymes contributing to decreasing fatty acid levels. Notably, this decrease consequently showed a suppressing effect on the CPT-1 activity. We suggest that epistructured catechin-induced apoptosis targets CPT-1 activity suppression mediated through diminishing the DNL pathway in HepG2 cells. In addition, increased ROS production was found after treatment with EGCG and EC, indicating oxidative stress mechanism-induced apoptosis. The strong apoptotic effect of EGCG and EC was specifically absent in primary human hepatocytes.

Conclusion

Our supportive evidence confirms potential alternative cancer treatments by EGCG and EC that selectively target the DNL pathway.

Astaxanthin ameliorates cerulein-induced acute pancreatitis in mice

BACKGROUND

A various of pharmacological effects of astaxanthin has been confirmed. However, the mechanism underlying protective effect of astaxanthin on acute pancreatitis (AP) induced by cerulein still unclear. The present study is to investigate the mechanism underlying the effect of astaxanthin on autophagy and apoptosis via the JAK/STAT3 pathway.

METHODS

Intraperitoneal injection of cerulein at hourly intervals followed by lipopolysaccharide injection were used in Balb/C mice. Vehicle or astaxanthin, which intraperitoneal injected in two doses (20 mg/kg and 40 mg/kg), were injected in mice 1 h before the first cerulein injection. At 3 h after the last injection, when the pathological changes were most severe, pancreatic tissue was analyzed by pathologically scored and hematoxylin and eosin (H&E) staining. The severity of AP was assessed by histological grading, proinflammatory cytokine levels, biochemistry, myeloperoxidase (MPO) activity, and analysis of JAK/STAT3 activity.

RESULTS

Astaxanthin administration markedly reduced serum digestive enzyme activities, pancreatic histological scores, proinflammatory cytokine levels (tumor necrosis factor-α (TNF-α), Interleukin-1β (IL-1β), and Interleukin-6 (IL-6)), MPO and JAK/STAT3 activity.

CONCLUSION

Collectively, these results indicate that astaxanthin inhibits pancreatic injury in AP by targeting JAK/STAT3-mediated apoptosis and autophagy.

Hepatoprotective effect of quercetin via TRAF6/JNK pathway in acute hepatitis

Quercetin, as a member of the flavonoids family, has many beneficial properties. The aim of our study was to evaluate the protective effect of quercetin in ConA-induced hepatitis in mice, and to clarify its mechanism of action. Hepatitis was induced by using ConA (25 mg/kg), and quercetin was administered intragastrically at the dose of 100 mg/kg or 200 mg/kg for 5 days before ConA injection. The serum levels of liver enzymes, inflammatory cytokines and other marker proteins were determined at 2 h, 8 h and 24 h after ConA injection. Following ConA injection, serum levels of liver enzymes and inflammatory cytokines were significantly increased. Quercetin ameliorated liver damage and histopathological changes, and suppressed the release of inflammatory cytokines. The expression of Bax, Bcl-2, Beclin-1, LC3, P62 and caspase 9 were markedly affected by quercetin pretreatment. The expression of TRAF6 and p-JNK were decreased in the quercetin groups. Quercetin attenuated apoptosis and autophagy in ConA-induced autoimmune hepatitis by inhibiting TRAF6/JNK pathway.

1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (PLAG) reduces hepatic injury in concanavalin A-treated mice

1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (PLAG), a chemically synthesized monoacetyldiaglyceride, is one of the constituents in Sika deer antlers and has been known traditionally as having immunomodulatory effects. However, the mechanism by which PLAG controls neutrophil migration, which evokes liver injury in the hepatitis animal model, remains largely unknown. This study was designed to evaluate the immunomodulatory effects of PLAG on cytokine secretion and neutrophil migration in vivo and in vitro. Concanavalin A (Con A) induced leukocyte infiltration in the liver and increased plasma cytokine levels. Pretreatment with PLAG reduced the levels of interleukin (IL)-4, IL-6, IL-10, and CXCL2, but maintained interferon (IFN)-γ levels and modulated neutrophil recruitment toward the liver. Furthermore, the mRNA and protein levels of IL-4 and CXCL2 in liver tissue were also decreased in the Con A-treated mice. Liver histology analyses showed that PLAG reduced Con A-induced hepatic necrosis, which was accompanied by leukocyte infiltration. The in vitro studies revealed that PLAG reduced IL-4 secretion in Con A stimulated T cell and blocked signal transducer and activator of transcription 6 (STAT6) Con A induced hepatocyte. PLAG attenuated IL-4 induced activation of atypical protein kinase C (PKC)/STAT6 in hepatocytes and inhibited neutrophil migration toward the liver tissue through suppression of IL-8/vascular cell adhesion molecule (VCAM) expression. These results suggest that PLAG could mitigate excess neutrophil migration into liver tissue and potentially have a therapeutic effect on immune-mediated liver injury.

The liver protection of propylene glycol alginate sodium sulfate preconditioning against ischemia reperfusion injury: focusing MAPK pathway activity

Hepatic ischemia reperfusion (IR) injury contributes to the morbidity and mortality associated with liver surgery. This study investigated the protective function and mechanism of propylene glycol alginate sodium sulfate (PSS), a sulfated polysaccharide, in a mouse hepatic IR injury model. PSS (25 or 50 mg/kg) or saline were injected intraperitoneally to male Balb/c mice 1 h before 45 min of 70% warm hepatic ischemia and 2, 8, and 24 h of reperfusion. Serum and liver tissue samples were collected for evaluation of hepatocellular damage, liver histology, and assay of inflammatory cytokines, apoptosis- and autophagy-related proteins, and proteins in the mitogen-activated protein kinase (MAPKs). Histological injury and release of transaminases, and inflammatory cytokine production were significantly reduced by PSS pretreatment. The expression of apoptosis- and autophagy-related proteins, and the activation of MAPK signal, including jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and P38 were all affected by PSS treatment compared with IR model controls. PSS protected the liver from IR injury by suppressing the MAPK signaling and down-regulating inflammation, apoptosis, and autophagy.

A new molecular mechanism underlying the EGCG-mediated autophagic modulation of AFP in HepG2 cells

Epigallocatechingallate (EGCG) is a major bioactive component of green tea and is associated with health benefits against multiple diseases including cancer. As an indicator of hepatocellular carcinoma (HCC), high levels of α-fetal protein (AFP) are related to malignant differentiation and poor prognosis of cancer cells. In this study, EGCG can effectively reduce AFP secretion and simultaneously induce AFP aggregation in human HCC HepG₂ cells. EGCG-stimulated autophagy induces the degradation of AFP aggregates in HepG₂ cells. Furthermore, we thoroughly studied the underlying molecular mechanisms behind EGCG-stimulated autophagy by using large-scale all-atom molecular dynamics simulations, which revealed a novel molecular mechanism. EGCG directly interacts with LC3-I protein, readily exposing the pivotal Gly-120 site of the latter to other important binding partners such as 1,2-distearoyl-sn-glycero-3-phosphoethanolamine and promoting the synthesis of LC3-II, a characteristic autophagosomal marker. Our results suggest that EGCG is critical in regulating AFP secretion and in modulating autophagic activities of HepG₂ cells, providing a molecular basis for potentially preventing and treating HCC.

Green tea protects against memory deficits related to maternal deprivation

Maternal deprivation (MD) in early life affects the development of the brain, causing cognitive losses in adulthood. Oxidative imbalance may be one of the factors that trigger these deficits. Therapies with antioxidant components, like green tea from Camellia sinensis (GT) has been used to treat or prevent memory deficits in a variety of conditions related to oxidative stress. Here we demonstrate that memory deficits caused by MD can be prevented by GT antioxidant activity in hippocampus. Pregnant female rats were used. Her puppies were submitted to MD and intake of GT. Recognition and aversive memory were evaluated, as well as hippocampal oxidative status. Data showed that MD prejudice short and long-term recognition and aversive memory and that GT protected memory. Hippocampal reactive oxygen species levels were increased in MD rats; this increase was avoided by GT supplementation. GSH was decreased on hippocampus MD rats. GT did not avoid GSH decrease, but promote the increase of total antioxidant capacity in MD rats' hippocampus. In conclusion, GT protects against memory deficits related to MD, and one of the implicated mechanism seems to be the antioxidant effects of GT.

The natural product fucoidan ameliorates hepatic ischemia-reperfusion injury in mice

Fucoidan is a sulfated polysaccharide based predominantly on l-fucose, and has several biologic functions. Reactive oxygen species-mediated apoptosis and autophagy and release of related inflammatory factors have important roles in hepatic ischemia-reperfusion injury (IR). Here, the effect of fucoidan on hepatic IR was investigated. Mice were randomized into sham, IR, and fucoidan (20, 40mg/kg for 14days) groups. Samples were collected to assess biochemical indicators, hepatocyte damage and levels of proteins related to signaling pathways at different time points. Fucoidan had no effect on normal liver tissue, but inhibited the increases in alanine aminotransferase, aspartate transaminase, inflammatory factors, and the hepatocyte damage caused by IR. Also, apoptosis and autophagy via the activated JAK2/STAT1 pathway were attenuated by fucoidan to protect against hepatic injury. In conclusion, fucoidan ameliorates hepatic IR injury in mice via JAK2/STAT1-mediated apoptosis and autophagy. Inhibition of this pathway may be associated with reduced release of related inflammatory cytokines, especially interferon-γ.

Liver toxicity mechanisms of herbs commonly used in Latin America

Mexico owns approximately 4500 medicinal plants species, a great diversity that position it at the second place after China. According to the Mexican health department, 90% of common population consumes them to treat various diseases. Additionally, herbal remedies in Latin America (LA) are considered a common practice, but the frequency of use and the liver damage related to its consumption is still unknown. Despite the high prevalence and indiscriminate herbal consumption, the exact mechanism of hepatotoxicity and adverse effects is not fully clarified and is still questioned. Some herb products associated with herb induced liver injury (HILI) are characterized by presenting a different chemical composition that may vary from batch to batch, also the biological activity of many medicinal plants and other natural products are directly related to their most active component and its concentration. There are two main biological components that are associated with liver damage, alkaloids, and flavonoids, which are frequent constituents of commonly used herbs. The interaction with the different cytochrome P-450 isoforms, inflammatory, and oxidative activities seem to be the main damage pathway involved in the liver. It is important to know the herbal adverse effects and mechanisms involved; therefore, this article is focused on the beneficial and deleterious effects as well as the possible toxicity mechanisms and interactions of the herbs that are frequently used in LA, since the herb-host interaction may not always be the expected or desired depending on the clinical context in which it is administered.

15-Deoxy-Δ12,14-prostaglandin J2 alleviates hepatic ischemia-reperfusion injury in mice via inducing antioxidant response and inhibiting apoptosis and autophagy

Hepatic ischemia-reperfusion (I/R) injury is a common clinical impairment that occurs in many circumstances and leads to poor prognosis. Both apoptosis and autophagy have been shown to contribute to cell death in hepatic I/R injury. 15-Deoxy-Δ^12,14-prostaglandin J₂ (15d-PGJ2) is one of the best-studied anti-inflammatory prostaglandins, which has been verified to exert anti-inflammatory and cell-protective functions in various types of cells and animal models. In this study we explored the effects of 15d-PGJ2 on both apoptosis and autophagy in mouse hepatic I/R injury and its possible mechanisms. A model of segmental (70%) hepatic warm ischemia was established in Balb/c mice, and the pathological changes in serum and liver tissues were detected at 6, 12, and 24 h post-surgery, while 15d-PGJ2 (2.5, 7.5, 15 μg, iv) was administered 30 min prior the surgery. Pretreatment with 15d-PGJ2 (7.5, 15 μg) significantly ameliorated I/R-induced hepatic injury evidenced by dose-dependent reduction of serum ALT and AST levels as well as alleviated tissue damages. 15d-PGJ2 pretreatment significantly decreased the serum TNF-α and IL-1β levels and the hepatic expression of F4/80, a major biomarker of macrophages. 15d-PGJ2 pretreatment upregulated the Bcl-2/Bax ratio, thus reducing the number of apoptotic cells in the livers. 15d-PGJ2 pretreatment considerably suppressed the expression of Beclin-1 and LC3, thus decreasing the number of autophagosomes in the livers. Furthermore, 15d-PGJ2 pretreatment activated Nrf2 and inhibited a ROS/HIF1α/BNIP3 pathway in the livers. Pretreatment with the PPARγ receptor blocker GW9662 (2 μg, ip) partly reversed the protective effects of 15d-PGJ2 on hepatic I/R injury. In conclusion, our results confirm the protective effect of 15d-PGJ2 on hepatic I/R injury, an effect that may rely on a reduction in the activation of Kupffer cells and on activation of the Nrf2 pathway, which lead to inhibition of ROS generation, apoptosis, and autophagy.

The protective effects of shikonin on hepatic ischemia/reperfusion injury are mediated by the activation of the PI3K/Akt pathway

Hepatic ischemia/reperfusion (I/R) injury, which can result in severe liver injury and dysfunction, occurs in a variety of conditions such as liver transplantation, shock, and trauma. Cell death in hepatic I/R injury has been linked to apoptosis and autophagy. Shikonin plays a significant protective role in ischemia/reperfusion injury. The purpose of the present study was to investigate the protective effect of shikonin on hepatic I/R injury and explore the underlying mechanism. Mice were subjected to segmental (70%) hepatic warm ischemia to induce hepatic I/R injury. Two doses of shikonin (7.5 and 12.5 mg/kg) were administered 2 h before surgery. Balb/c mice were randomly divided into four groups: normal control, I/R, and shikonin preconditioning at two doses (7.5 and 12.5 mg/kg). The serum and liver tissues were collected at three time points (3, 6, and 24 h). Shikonin significantly reduced serum AST and ALT levels and improved pathological features. Shikonin affected the expression of Bcl-2, Bax, caspase 3, caspase 9, Beclin-1, and LC3, and upregulated PI3K and p-Akt compared with the levels in the I/R group. Shikonin attenuated hepatic I/R injury by inhibiting apoptosis and autophagy through a mechanism involving the activation of PI3K/Akt signaling.

In vitro and in vivo study of epigallocatechin-3-gallate-induced apoptosis in aerobic glycolytic hepatocellular carcinoma cells involving inhibition of phosphofructokinase activity

Glycolysis, as an altered cancer cell-intrinsic metabolism, is an essential hallmark of cancer. Phosphofructokinase (PFK) is a metabolic sensor in the glycolytic pathway, and restricting the substrate availability for this enzyme has been researched extensively as a target for chemotherapy. In the present study, we investigated that the effects of epigallocatechin-3-gallate (EGCG), an active component of green tea, on inhibiting cell growth and inducing apoptosis by promoting a metabolic shift away from glycolysis in aerobic glycolytic hepatocellular carcinoma (HCC) cells. EGCG modulated the oligomeric structure of PFK, potentially leading to metabolic stress associated apoptosis and suggesting that EGCG acts by directly suppressing PFK activity. A PFK activity inhibitor enhanced the effect, while the allosteric activator reversed EGCG-induced HCC cell death. PFK siRNA knockdown-induced apoptosis was not reversed by the activator. EGCG enhanced the effect of sorafenib on cell growth inhibition in both aerobic glycolytic HCC cells and in a xenograft mouse model. The present study suggests a potential role for EGCG as an adjuvant in cancer therapy, which merits further investigation at the clinical level.

15d-PGJ2 alleviates ConA-induced acute liver injury in mice by up-regulating HO-1 and reducing hepatic cell autophagy

OBJECTIVE

In this study, we confirmed a protective effect of 15d-PGJ2 in concanavalin A (ConA)-induced fulminant hepatitis in mice and investigated the potential mechanism.

MATERIALS AND METHODS

Balb/C mice were injected with ConA (25mg/kg) to induce acute fulminant hepatitis, and 15d-PGJ2 (2.5-10μg) was administered 30min after the ConA injection. The histological grade, pro-inflammatory cytokine and ROS levels, apoptosis and autophagy activity, the expression of HO-1, Nrf2, JNK and Bcl-2 activity were determined 2, 4, and 8h after the ConA injection.

RESULTS

Following ConA challenge, the expression of cytokines tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) was up-regulated. Treatment with 15d-PGJ2 reduced the pathological effects of ConA-induced fulminant hepatitis and significantly reduced the levels of TNF-α, IL-1β and ROS after injection. 15d-PGJ2 inhibited apoptosis and autophagic cell death, facilitated Nrf2 nuclear translocation, increased HO-1 expression and suppressed the JNK activation.

CONCLUSION

15d-PGJ2 alleviates ConA-induced acute liver injury in mice by up-regulating the anti-oxidative stress factor HO-1 and reducing the production of cytokines and ROS, thereby inhibiting hepatic cell autophagy probably induced by ROS.