Induction of heat shock protein 27 by bicyclol attenuates d-galactosamine/lipopolysaccharide-induced liver injury

Expanding the horizons of bicyclol in multiple diseases: Mechanisms, therapeutic implications and challenges

Bicyclol, a drug stemmed from the traditional Chinese medicine Schisandra chinensis, has been widely utilized in clinical practice due to its efficacy and safety to manage hepatopathy. Its diverse biological properties-including antiviral, anti-inflammatory, antifibrotic, immunomodulatory, antioxidative, antisteatotic, and antitumor effects-underscore its significant medicinal effects in versatile hepatic disorders, incorporating viral hepatitis, non-alcoholic fatty liver disease, hepatocellular carcinoma, acute hepatic failure, hepatic fibrosis as well as drug-induced liver injury. Furthermore, ongoing researches into the molecular mechanisms, biological activities and mode of actions concerning bicyclol have uncovered its potential therapeutic implications in other multiple diseases/conditions. Studies have indicated promising efficacy pertaining to bicyclol to treat idiopathic pulmonary fibrosis, acute lung injury, cerebral ischemia/reperfusion injury, renal dysfunction, renal cell carcinoma, and cardiovascular diseases. Accordingly, this narrative review article summarizes the current understanding of diverse biological activities and underpinning mechanisms of bicyclol across a range of diseases, as well as its pharmacokinetics, toxicity profile and shed light on future perspectives.

Luteolin enhanced antioxidant capability and induced pyroptosis through NF-κB/NLRP3/Caspase-1 in splenic lymphocytes exposure to ammonia

During feeding process in intensive chicken farms, the prolonged exposure of chickens to elevated level of ammonia leads to substantial economic losses within poultry farming industry. Luteolin (Lut), known as its anti-inflammatory and antioxidant properties, possesses the ability to eliminate free radicals and enhance the activities of antioxidant enzymes, thus rendering it highly esteemed in production. The objective of this study was to examine the effects of Lut on antioxidant and anti-inflammatory responses of chicken splenic lymphocytes exposed to ammonia. In order to achieve this, we have replicated a protective model involving Lut against ammonia exposure in chicken splenic lymphocytes. The findings of the study indicated that Lut mitigated the elevation of lactate dehydrogenase (LDH), malondialdehyde (MDA), and reactive oxygen species (ROS) induced by ammonia poisoning. Additionally, Lut demonstrated an increase in the expression of antioxidant enzymes, namely superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). Furthermore, Lut exhibited a protective effect on cell morphology and ultrastructure following exposure to ammonia. Moreover, Lut exhibited a reduction in the expression of heat shock proteins (HSPs) and inflammatory cytokines, which were found to be highly expressed in splenic lymphocytes after ammonia exposure. Additionally, Lut demonstrated the ability to inhibit the overexpression of pyroptosis-related genes and proteins (NLRP3 and Caspase-1) in splenic lymphocytes following ammonia exposure. Lut exerted an antioxidant effect on lymphocytes, counteracting elevated levels of oxidative stress following exposure to ammonia. Additionally, Lut had the potential to modulate the expression of HSPs, suppressed the inflammatory response subsequent to ammonia exposure, and influenced the expression of NLRP3 and Caspase-1, thereby mitigating pyroptosis induced by ammonia exposure. The exploration of this subject matter can elucidate the protective properties of Lut against NH4Cl-induced damage in chicken splenic lymphocytes, while also offer insights and experimental groundwork for the utilization of natural therapeutics in animal husbandry to prevent and treat ammonia-related conditions.

Orchestrated regulation of immune inflammation with cell therapy in pediatric acute liver injury

Acute liver injury (ALI) in children, which commonly leads to acute liver failure (ALF) with the need for liver transplantation, is a devastating life-threatening condition. As the orchestrated regulation of immune hemostasis in the liver is essential for resolving excess inflammation and promoting liver repair in a timely manner, in this study we focused on the immune inflammation and regulation with the functional involvement of both innate and adaptive immune cells in acute liver injury progression. In the context of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic, it was also important to incorporate insights from the immunological perspective for the hepatic involvement with SARS-CoV-2 infection, as well as the acute severe hepatitis of unknown origin in children since it was first reported in March 2022. Furthermore, molecular crosstalk between immune cells concerning the roles of damage-associated molecular patterns (DAMPs) in triggering immune responses through different signaling pathways plays an essential role in the process of liver injury. In addition, we also focused on DAMPs such as high mobility group box 1 (HMGB1) and cold-inducible RNA-binding protein (CIRP), as well as on macrophage mitochondrial DNA-cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway in liver injury. Our review also highlighted novel therapeutic approaches targeting molecular and cellular crosstalk and cell-based therapy, providing a future outlook for the treatment of acute liver injury.

The Immune Pathogenesis of Acute-On-Chronic Liver Failure and the Danger Hypothesis

Acute-on-chronic liver failure (ACLF) is a group of clinical syndromes related to severe acute liver function impairment and multiple-organ failure caused by various acute triggering factors on the basis of chronic liver disease. Due to its severe condition, rapid progression, and high mortality, it has received increasing attention. Recent studies have shown that the pathogenesis of ACLF mainly includes direct injury and immune injury. In immune injury, cytotoxic T lymphocytes (CTLs), dendritic cells (DCs), and CD4⁺ T cells accumulate in the liver tissue, secrete a variety of proinflammatory cytokines and chemokines, and recruit more immune cells to the liver, resulting in immune damage to the liver tissue, massive hepatocyte necrosis, and liver failure, but the key molecules and signaling pathways remain unclear. The “danger hypothesis” holds that in addition to the need for antigens, damage-associated molecular patterns (DAMPs) also play a very important role in the occurrence of the immune response, and this hypothesis is related to the pathogenesis of ACLF. Here, the research status and development trend of ACLF, as well as the mechanism of action and research progress on various DAMPs in ACLF, are summarized to identify biomarkers that can predict the occurrence and development of diseases or the prognosis of patients at an early stage.

Therapeutic potential of bicyclol in liver diseases: Lessons from a synthetic drug based on herbal derivative in traditional Chinese medicine

Bicyclol, an innovative chemical drug with proprietary intellectual property rights in China, is based on derivative of traditional Chinese medicine (TCM) Schisandra chinensis (Wuweizi) of North. Mounting data has proved that bicyclol has therapeutic potential in various pathological conditions in liver. In this narrative review, we provide the first summary of pharmacological activities, pharmacokinetic characteristics and toxicity of bicyclol, and discuss future research perspectives. Our results imply that bicyclol has a wide spectrum of pharmacological properties, including anti-viral, anti-inflammatory, immuno-regulatory, anti-oxidative, antisteatotic, anti-fibrotic, antitumor, cell death regulatory effects and modulation of heat shock proteins. Pharmacokinetic studies have indicated that bicyclol is the main substrate of CYP3A/2E1. Additionally, no obvious drug interactions have been found when bicyclol is administered simultaneously with other prescriptions. Furthermore, the results of chronic toxicity have strongly addressed that bicyclol has no noticeable toxic effects on all biochemical indices and pathological examinations of the main organs. In view of good pharmacological actions and safety, bicyclol is anticipated to be a potential candidate for various liver diseases, including acute liver injury, fulminant hepatitis, non-alcoholic fatty liver disease, fibrosis and hepatocellular carcinoma. Further studies are therefore required to delineate its molecular mechanisms and targets to confer this well-designed drug a far greater potency. We hope that bicyclol-based therapeutics for liver diseases might be broadly used in clinical practice worldwide.

HSPA12A attenuates lipopolysaccharide-induced liver injury through inhibiting caspase-11-mediated hepatocyte pyroptosis via PGC-1α-dependent acyloxyacyl hydrolase expression

Liver dysfunction is strongly associated with poor survival of sepsis patients. Cytosolic lipopolysaccharide (LPS) sensing by Caspase-4/5/11 for pyroptosis activation is a major driver of the development of sepsis. Studies in macrophages and endothelial cells have demonstrated that LPS is inactivated by acyloxyacyl hydrolase (AOAH) and leading to desensitizing Caspase-4/5/11 to LPS. However, little is known about the cytosolic LPS-induced pyroptosis in hepatocytes during sepsis. Heat shock protein 12A (HSPA12A) is a novel member of the HSP70 family. Here, we report that LPS increased HSPA12A nuclear translocation in hepatocytes, while knockout of HSPA12A (Hspa12a^−/−) in mice promoted LPS-induced acute liver injury. We also noticed that the LPS-induced Caspase-11 activation and its cleavage of gasdermin D (GSDMD) to produce the membrane pore-forming GSDMD^Nterm (markers of pyroptosis) were greater in livers of Hspa12a^−/− mice compared with its wild type controls. Loss- and gain-of-function studies showed that HSPA12A deficiency promoted, whereas HSPA12A overexpression inhibited, cytosolic LPS accumulation, Caspase-11 activation and GSDMD^Nterm generation in primary hepatocytes following LPS incubation. Notably, LPS-induced AOAH expression was suppressed by HSPA12A deficiency, whereas AOAH overexpression reversed the HSPA12A deficiency-induced promotion of LPS-evoked and Caspase-11-mediated pyroptosis of hepatocytes. In-depth molecular analysis showed that HSPA12A interacted directly with peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) and increased its nuclear translocation, thereby inducing AOAH expression for cytosolic LPS inactivation, which ultimately leading to inhibition of the Caspase-11 mediated pyroptosis of hepatocytes. Taken together, these findings revealed HSPA12A as a novel player against LPS-induced liver injury by inhibiting cytosolic LPS-induced hepatocyte pyroptosis via PGC-1α-mediated AOAH expression. Therefore, targeting hepatocyte HSPA12A represents a viable strategy for the management of liver injury in sepsis patients.

Bicyclol Attenuates Acute Liver Injury by Activating Autophagy, Anti-Oxidative and Anti-Inflammatory Capabilities in Mice

Bicyclol, a novel synthetic antihepatitis drug, has been shown to protect against liver injury via various pharmacological activities. The purpose of the current study was to further investigate the protective effect of bicyclol against carbon tetrachloride (CCl4)-induced acute liver injury (ALI) and its underlying molecular mechanism, particularly autophagic machinery, anti-oxidative, and anti-inflammatory potentials. Our results found that treatment with bicyclol significantly reduced CCl4-induced hepatotoxicity by alleviating histopathological liver changes, decreasing the alanine transaminase levels, promoting autophagic flux, attenuating the expression of inflammatory cytokines, and modulating oxidative markers. Furthermore, bicyclol efficiently induced the conversion of LC3 and enhanced the liver expressions of ATG7 and Beclin-1. Meanwhile, bicyclol induced the activation of nuclear factor erythroid 2-related factor 2 (Nrf2) and p62. These protective effects may be mediated by activation of AMP-activated protein kinase and inhibition of mTOR or MAPK signaling pathways. Taken together, our study firstly suggests that bicyclol has protective potential against CCl4-induced hepatotoxicity, which might be closely associated with induction of autophagy, concomitant anti-oxidative stress, and anti-inflammatory response.

Fucoidan Alleviates Acetaminophen-Induced Hepatotoxicity via Oxidative Stress Inhibition and Nrf2 Translocation

Acetaminophen (APAP) is a widely used analgesic and antipyretic drug that leads to severe hepatotoxicity at excessive doses. Fucoidan, a sulfated polysaccharide derived from brown seaweeds, possesses a wide range of pharmacological properties. However, the impacts of fucoidan on APAP-induced liver injury have not been sufficiently addressed. In the present study, male Institute of Cancer Research (ICR) mice aged 6 weeks were subjected to a single APAP (500 mg/kg) intraperitoneal injection after 7 days of fucoidan (100 or 200 mg/kg/day) or bicyclol intragastric administration. The mice continued to be administered fucoidan or bicyclol once per day, and were sacrificed at an indicated time. The indexes evaluated included liver pathological changes, levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the serum, levels of reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH) and catalase (CAT) in the liver, and related proteins levels (CYP2E1, pJNK and Bax). Furthermore, human hepatocyte HL-7702 cell line was used to elucidate the potential molecular mechanism of fucoidan. The mitochondrial membrane potential (MMP) and nuclear factor-erythroid 2-related factor (Nrf2) translocation in HL-7702 cells were determined. The results showed that fucoidan pretreatment reduced the levels of ALT, AST, ROS, and MDA, while it enhanced the levels of GSH, SOD, and CAT activities. Additionally, oxidative stress-induced phosphorylated c-Jun N-terminal protein kinase (JNK) and decreased MMP were attenuated by fucoidan. Although the nuclear Nrf2 was induced after APAP incubation, fucoidan further enhanced Nrf2 in cell nuclei and total expression of Nrf2. These results indicated that fucoidan ameliorated APAP hepatotoxicity, and the mechanism might be related to Nrf2-mediated oxidative stress.

Interleukin-23 mediates the pathogenesis of LPS/GalN-induced liver injury in mice

BACKGROUND

Interleukin-23 (IL-23) is required for T helper 17 (Th17) cell responses and IL-17 production in hepatitis B virus infection. A previous study showed that the IL-23/IL-17 axis aggravates immune injury in patients with chronic hepatitis B virus infection. However, the role of IL-23 in acute liver injury remains unclear.

OBJECTIVE

The purpose of this study was to determine the role of the inflammatory cytokine IL-23 in lipopolysaccharide/d-galactosamine (LPS/GalN)-induced acute liver injury in mice.

METHODS

Serum IL-23 from patients with chronic hepatitis B virus (CHB), acute-on-chronic liver failure (ACLF) and healthy individuals who served as healthy controls (HCs) was measured by ELISA. An IL-23p19 neutralizing antibody or an IL-23p40 neutralizing antibody was administered intravenously at the time of challenge with LPS (10μg/kg) and GalN (400mg/kg) in C57BL/6 mice. Hepatic pathology and the expression of Th17-related cytokines, including IL-17 and TNF-α; neutrophil chemoattractants, including Cxcl1, Cxcl2, Cxcl9, and Cxcl10; and the stabilization factor Csf3 were assessed in liver tissue.

RESULTS

Serum IL-23 was significantly upregulated in ACLF patients compared with CHB patients and HCs (P<0.05 for both). Serum IL-23 was significantly upregulated in the non-survival group compared with the survival group of ACLF patients, which was consistent with LPS/GalN-induced acute hepatic injury in mice (P<0.05 for both). Moreover, after treatment, serum IL-23 was downregulated in the survival group of ACLF patients (P<0.001). Compared with LPS/GalN mice, mice treated with either an IL-23p19 neutralizing antibody or an IL-23p40 neutralizing antibody showed less severe liver tissue histopathology and significant reductions in the expression of Th17-related inflammatory cytokine, including IL-17 and TNF-α; neutrophil chemoattractants, including Cxcl1, Cxcl2, Cxcl9, and Cxcl10; and stabilization factors Csf3 within the liver tissue compared with LPS/GalN mice (P<0.05 for all).

CONCLUSION

High serum IL-23 was associated with mortality in ACLF patients and LPS/GalN-induced acute liver injury in mice. IL-23 neutralizing antibodies attenuated liver injury by reducing the expression of Th17-related inflammatory cytokines, neutrophil chemoattractants and stabilization factors within the liver tissue, which indicated that IL-23 likely functions upstream of Th17-related cytokine and chemokine expression to recruit inflammatory cells into the liver.