Curcumin protects mice against concanavalin A-induced hepatitis by inhibiting intrahepatic intercellular adhesion molecule-1 (ICAM-1) and CXCL10 expression

Nutrients Lowering Obesity-Linked Chemokines Blamable for Metastasis

Food intake is an essential contributor to both health and disease. Nutrients contribute to a beneficial metabolic equilibrium at the cellular level, preventing or delaying disease onset. Dietary intake contributes to obesity, and obesity supports further cancer and metastasis. Metastasis, a multifactorial and multistep process, is supported by the systemic inflammation of obesity. Spreading of the cancer cells requires the presence of a plethora of recruiter and regulator molecules. Molecules such as chemokines are provided at high levels by obesity-associated fat depots. Chemokine up-regulation in adipose tissue of obese individuals has been associated with different types of cancers such as breast, prostate, colon, liver, and stomach. Chemokines support all metastasis steps from invasion/migration to intravasation, circulation, extravasation, and ending with colonization. The obesity pool of chemokines supporting these processes includes CCL2, CCL3, CCL4, CCL5, CCL7, CCL8, CCL11, CCL18, CCL19, CCL20, CXCL1, CXCL5, CXCL 8, CXCL10, and CXCL12. Keeping obesity under control can be beneficial in reducing the levels of pro-inflammatory chemokines and the risk of poor cancer outcome. Nutrients can help, support, and boost cancer treatment effects or jeopardize the treatment. Constituents with anti-inflammatory and anti-obesity properties such as polyphenols, organosulfur components, fatty acids, curcumin, and vitamin E have a proven beneficial effect in lowering obesity and its contribution to metastasis.

Current investigations for liver fibrosis treatment: between repurposing the FDA-approved drugs and the other emerging approaches

Long-term liver injuries lead to hepatic fibrosis, often progressing into cirrhosis, liver failure, portal hypertension, and hepatocellular carcinoma. There is currently no effective therapy available for liver fibrosis. Thus, continuous investigations for anti-fibrotic therapy are ongoing. The main theme of anti-fibrotic investigation during recent years is the rationale-based selection of treatment molecules according to the current understanding of the pathology of the disease. The research efforts are mainly toward repurposing current FDA-approved drugs targeting etiological molecular factors involved in developing liver fibrosis. In parallel, investigations also focus on experimental small molecules with evidence to hinder or reverse the fibrosis. Natural compounds, immunological, and genetic approaches have shown significant encouraging effects. This review summarizes the efficacy and safety of current under-investigation antifibrosis medications targeting various molecular targets, as well as the properties of antifibrosis medications, mainly in phase II and III clinical trials.

Curcumin and chemokines: mechanism of action and therapeutic potential in inflammatory diseases

Chemokines belong to the family of cytokines with chemoattractant properties that regulate chemotaxis and leukocyte migration, as well as the induction of angiogenesis and maintenance of hemostasis. Curcumin, the major component of the Curcuma longa rhizome, has various pharmacological actions, including anti-inflammatory, immune-regulatory, anti-oxidative, and lipid-modifying properties. Chemokines and chemokine receptors are influenced/modulated by curcumin. Thus, the current review focuses on the molecular mechanisms associated with curcumin's effects on chemoattractant cytokines, as well as putting into context the many studies that have reported curcumin-mediated regulatory effects on inflammatory conditions in the organs/systems of the body (e.g., the central nervous system, liver, and cardiovascular system). Curcumin's effects on viral and bacterial infections, cancer, and adverse pregnancy outcomes are also reviewed.

The role of curcumin in the liver-gut system diseases: from mechanisms to clinical therapeutic perspective

Natural products have provided abundant sources of lead compounds for new drug discovery and development over the past centuries. Curcumin is a lipophilic polyphenol isolated from turmeric, a plant used in traditional Asian medicine for centuries. Despite the low oral bioavailability, curcumin exhibits profound medicinal value in various diseases, especially liver and gut diseases, bringing an interest in the paradox of its low bioavailability but high bioactivity. Several latest studies suggest that curcumin's health benefits may rely on its positive gastrointestinal effects rather than its poor bioavailability solely. Microbial antigens, metabolites, and bile acids regulate metabolism and immune responses in the intestine and liver, suggesting the possibility that the liver-gut axis bidirectional crosstalk controls gastrointestinal health and diseases. Accordingly, these pieces of evidence have evoked great interest in the curcumin-mediated crosstalk among liver-gut system diseases. The present study discussed the beneficial effects of curcumin against common liver and gut diseases and explored the underlying molecular targets, as well as collected evidence from human clinical studies. Moreover, this study summarized the roles of curcumin in complex metabolic interactions in liver and intestine diseases supporting the application of curcumin in the liver-gut system as a potential therapeutic option, which opens an avenue for clinical use in the future.

Understanding the Potential Role of Nanotechnology in Liver Fibrosis: A Paradigm in Therapeutics

The liver is a vital organ that plays a crucial role in the physiological operation of the human body. The liver controls the body's detoxification processes as well as the storage and breakdown of red blood cells, plasma protein and hormone production, and red blood cell destruction; therefore, it is vulnerable to their harmful effects, making it more prone to illness. The most frequent complications of chronic liver conditions include cirrhosis, fatty liver, liver fibrosis, hepatitis, and illnesses brought on by alcohol and drugs. Hepatic fibrosis involves the activation of hepatic stellate cells to cause persistent liver damage through the accumulation of cytosolic matrix proteins. The purpose of this review is to educate a concise discussion of the epidemiology of chronic liver disease, the pathogenesis and pathophysiology of liver fibrosis, the symptoms of liver fibrosis progression and regression, the clinical evaluation of liver fibrosis and the research into nanotechnology-based synthetic and herbal treatments for the liver fibrosis is summarized in this article. The herbal remedies summarized in this review article include epigallocathechin-3-gallate, silymarin, oxymatrine, curcumin, tetrandrine, glycyrrhetinic acid, salvianolic acid, plumbagin, Scutellaria baicalnsis Georgi, astragalosides, hawthorn extract, and andrographolides.

Deoxynivalenol exposure induces liver damage in mice: Inflammation and immune responses, oxidative stress, and protective effects of Lactobacillus rhamnosus GG

Deoxynivalenol (DON), one of the most common environmental pollutants, substantially affects human and animal health. Much attention has been paid to the ability of probiotics to modulate inflammation and immune responses. In this work, the toxic effects of DON on the liver and the protective effects of Lactobacillus rhamnosus GG (LGG) were investigated. We treated mice with oral gavage of DON (2.4 mg/kg bw/day), LGG (1 × 10⁹ CFU/mouse/day) or both for 28 days. The results showed that DON triggered liver inflammation, reflected by pathological changes and liver function damage but LGG oral administration significantly attenuated these changes. Notably, DON treatment activated the TLR4/NF-κB signaling pathway which contribute to produce inflammatory cytokines, but oral administration of LGG inhibited all the effects of DON. DON treatment can also induce oxidative stress and activate Keap1-Nrf2 signaling pathway, leading to the activation of Nrf2 and the downstream genes, while LGG treatment can improve the antioxidant capacity of liver and protected mice from DON injury. In conclusion, LGG was able to negate the detrimental effects of DON on the liver and may contribute as a potential dietary intervention strategy to reduce mycotoxicity.

Discovering the Protective Effects of Resveratrol on Aflatoxin B1-Induced Toxicity: A Whole Transcriptomic Study in a Bovine Hepatocyte Cell Line

Aflatoxin B1 (AFB1) is a natural feed and food contaminant classified as a group I carcinogen for humans. In the dairy industry, AFB1 and its derivative, AFM1, are of concern for the related economic losses and their possible presence in milk and dairy food products. Among its toxic effects, AFB1 can cause oxidative stress. Thus, dietary supplementation with natural antioxidants has been considered among the strategies to mitigate AFB1 presence and its toxicity. Here, the protective role of resveratrol (R) has been investigated in a foetal bovine hepatocyte cell line (BFH12) exposed to AFB1, by measuring cytotoxicity, transcriptional changes (RNA sequencing), and targeted post-transcriptional modifications (lipid peroxidation, NQO1 and CYP3A enzymatic activity). Resveratrol reversed the AFB1-dependent cytotoxicity. As for gene expression, when administered alone, R induced neglectable changes in BFH12 cells. Conversely, when comparing AFB1-exposed cells with those co-incubated with R+AFB1, greater transcriptional variations were observed (i.e., 840 DEGs). Functional analyses revealed that several significant genes were involved in lipid biosynthesis, response to external stimulus, drug metabolism, and inflammatory response. As for NQO1 and CYP3A activities and lipid peroxidation, R significantly reverted variations induced by AFB1, mostly corroborating and/or completing transcriptional data. Outcomes of the present study provide new knowledge about key molecular mechanisms involved in R antioxidant-mediated protection against AFB1 toxicity.

The in Vitro Antischistosomal Activity and Genotoxicity of the Active Ingredients of Allium sativum (allicin) and Curcuma longa (curcumin)

Background:

In this study, we assessed the in vitro antischistosomal activity of the active ingredients of Allium sativum (allicin) and Curcuma longa (curcumin) on Schistosoma mansoni.

Methods:

This study was conducted in Faculty of Science, Port said University, Egypt (2018). Adult worms were exposed to a range of concentrations of AL or CU, and worm survival was assessed 24 h post-exposure to calculate the lethal concentration of the compounds. Scanning electron microscopy was used to assess ultrastructural changes in the surface of AL- or CU- treated worms. The genotoxicities of AL and CU on S. mansoni were determined by DNA fragmentation analysis.

Results:

We determined the concentrations of AL and CU required to kill 50% of S. mansoni (LC₅₀ ). The LC₅₀ of AL was 8.66 μL/mL, whereas 100% mortality of S. mansoni was achieved by AL at concentrations of 50 μL/mL. The LC₅₀ of CU was 87.25 μL/mL, with the highest mortality of 91.3% seen after 24 h exposure to 100 μg/mL CU. Ultrastructural studies revealed that exposure to either AL or CU led to mild or severe surface damage to S. mansion, respectively. The degree of damage in the worms was sex-dependent. Interestingly, while CU exposure resulted in DNA fragmentation in S. mansoni worms, we observed no genotoxic effects of AL.

Conclusion:

Both AL and CU exhibit antischistosomal activity; the study provided evidence suggesting that these compounds act through distinct mechanisms. These promising results encourage further investigation into these compounds as potential antischistosomal agents, either alone or as complementary treatments to praziquantel.

Summary of Natural Products Ameliorate Concanavalin A-Induced Liver Injury: Structures, Sources, Pharmacological Effects, and Mechanisms of Action

Liver diseases represent a threat to human health and are a significant cause of mortality and morbidity worldwide. Autoimmune hepatitis (AIH) is a progressive and chronic hepatic inflammatory disease, which may lead to severe complications. Concanavalin A (Con A)-induced hepatic injury is regarded as an appropriate experimental model for investigating the pathology and mechanisms involved in liver injury mediated by immune cells as well as T cell-related liver disease. Despite the advances in modern medicine, the only available strategies to treat AIH, include the use of steroids either solely or with immunosuppressant drugs. Unfortunately, this currently available treatment is associated with significant side-effects. Therefore, there is an urgent need for safe and effective drugs to replace and/or supplement those in current use. Natural products have been utilized for treating liver disorders and have become a promising therapy for various liver disorders. In this review, the natural compounds and herbal formulations as well as extracts and/or fractions with protection against liver injury caused by Con A and the underlying possible mechanism(s) of action are reviewed. A total of 53 compounds from different structural classes are discussed and over 97 references are cited. The goal of this review is to attract the interest of pharmacologists, natural product researchers, and synthetic chemists for discovering novel drug candidates for treating immune-mediated liver injury.

In vivo assessment of the antischistosomal activity of curcumin loaded nanoparticles versus praziquantel in the treatment of Schistosoma mansoni

Schistosomiasis is a serious parasitic infection affecting millions worldwide. This study aimed to explore the anti-schistosomal activity of curcumin and curcumin loaded gold-nanoparticles (Cur-GNPs) with or without praziquantel (PZQ). We used six groups of the C57BL/6 mice in which five groups were infected with Schistosoma Mansoni (S. mansoni) cercariae and exhibited, separately, to different treatment regimens of curcumin, curcumin loaded nanoparticle, and PZQ, in addition to one untreated group which acts as a control. Mice were sacrificed at the 8th week where both worms and eggs were counted in the hepatic and porto-mesenteric vessels in the liver and intestine, respectively, in addition to a histopathological examination of the liver granuloma. Curcumin caused a significant reduction in the worms and egg count (45.45%) at the 3rd week. A significant schistosomicidal effect of PZQ was found in all groups. Cur-GNPs combined with PZQ 97.4% reduction of worm burden in the 3rd week and the highest reduction in the intestinal and hepatic egg content, as well, besides 70.1% reduction of the granuloma size. The results suggested the curcumin in combination with PZQ as a strong schistosomicidal regimen against S. mansoni as it alters the hematological, biochemical, and immunological changes induced.

Liver Fibrosis: Mechanistic Concepts and Therapeutic Perspectives

Liver fibrosis due to viral or metabolic chronic liver diseases is a major challenge of global health. Correlating with liver disease progression, fibrosis is a key factor for liver disease outcome and risk of hepatocellular carcinoma (HCC). Despite different mechanism of primary liver injury and disease-specific cell responses, the progression of fibrotic liver disease follows shared patterns across the main liver disease etiologies. Scientific discoveries within the last decade have transformed the understanding of the mechanisms of liver fibrosis. Removal or elimination of the causative agent such as control or cure of viral infection has shown that liver fibrosis is reversible. However, reversal often occurs too slowly or too infrequent to avoid life-threatening complications particularly in advanced fibrosis. Thus, there is a huge unmet medical need for anti-fibrotic therapies to prevent liver disease progression and HCC development. However, while many anti-fibrotic candidate agents have shown robust effects in experimental animal models, their anti-fibrotic effects in clinical trials have been limited or absent. Thus, no approved therapy exists for liver fibrosis. In this review we summarize cellular drivers and molecular mechanisms of fibrogenesis in chronic liver diseases and discuss their impact for the development of urgently needed anti-fibrotic therapies.

Mycophenolate mofetil attenuates concanavalin A-induced acute liver injury through modulation of TLR4/NF-κB and Nrf2/HO-1 pathways

BACKGROUND

Acute liver injury (ALI) is a serious health condition associated with rising morbidity and sudden progression. This study was designed to investigate the possible hepatocurative potential of two dose levels (30 and 60 mg/kg) of Mycophenolate mofetil (MMF), an immune-suppressant agent, against Concanavalin A (Con A)-induced ALI in mice.

METHOD

A single dose of Con A (20 mg/kg, IV) was used to induce ALI in mice. MMF (30 mg/kg and 60 mg/kg) was administered orally for 4 days post Con A injection.

RESULTS

MMF (30 mg/kg) failed to cause significant amelioration in Con A-induced ALI while MMF (60 mg/kg) significantly alleviated Con A-induced ALI. Administration of MMF (60 mg/kg) significantly decreased Con A-induced increase in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels. Additionally, MMF significantly restored the disrupted oxidant/antioxidants status induced by Con A. MMF caused marked increase in hepatic nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) levels. Moreover, MMF significantly reduced Con A-induced increase in the expression of hepatic toll-like receptor 4 (TLR4), nuclear factor kappa-B (NF-κB), tumor necrosis factor-α (TNF-α), interferon-γ (INF-γ) and interleukin-1β (Il-1β). Also, MMF administration significantly decreased Con A-induced increase in the immune-expression of pro-apoptotic Bcl-2-associated X protein (Bax) and markedly increased Con A-induced decrease in the anti-apoptotic B-cell lymphoma 2 protein (Bcl2).

CONCLUSION

The observed ameliorative effect of MMF against Con A-induce ALI may be contributed to its anti-inflammatory, anti-oxidant and anti-apoptotic potentials taking into consideration that TLR4/NF-κB and Nrf2/HO-1 are the main implicated pathways. Schematic diagram summarizing the possible mechanisms underlying the ameliorative potential of Mycophenolate Mofetil against Con A-induced acute liver injury. Bax Bcl-2-associated X protein, Bcl2 B-cell lymphoma 2, MMF Mycophenolate mofetil, Con A Concanavalin A, GSH reduced glutathione, HO-1 Heme oxygenase-1, IL-1β Interleukin-1β, IFN-γ Interferon-γ, MDA Malondialdehyde, NF-κB Nuclear Factor Kappa B, Nrf2 Nuclear factor erythroid 2-related factor 2, NO Nitric Oxide, SOD Superoxide Dismutase, TLR4 Toll-like receptor 4, TNF-α tumor necrosis factor-α.

Protective effect of Salvia miltiorrhiza polysaccharides on liver injury in chickens

This study investigated the effects of Salvia miltiorrhiza polysaccharides (SMPs) on the injury of chicken hepatocytes in vitro and in vivo. In in vitro studies primary cultured hepatocytes were isolated by 2-step collagenase perfusion. Carbon tetrachloride (CCL4) was added to the hepatocytes to establish a hepatocyte injury model. Hepatocytes were treated with different concentrations of SMPs to detect the protective effects of SMPs on CCL4-induced hepatocyte injury. The results of the control group showed that chicken hepatocytes grew well and their morphology was normal. After CCL4 treatment, the activity of alanine transaminase (ALT) and aspartate transaminase (AST) of hepatocytes increased compared with the normal control group. SMPs treatment downregulated the contents of ALT, AST, and malondialdehyde (MDA), and upregulated the contents of glutathione (GSH) and cytochrome P450 (CYP450). An acute chicken liver injury model was established in vivo with 2.0 mL/kg 50% CCL4. Oral administration of SMP at different doses exhibited preventive success. The results showed that compared with the control group, the contents of total protein (TP), albumin (Alb), and GSH in the liver injury model group were significantly decreased and the levels of liver index, ALT, AST, and MDA were significantly increased. In contrast, in the SMP group the contents of TP, Alb, and GSH were significantly increased, and the levels of liver index, ALT, AST, and MDA were significantly decreased compared with the model group. Therefore, we conclude that SMPs have good protective effect on chicken liver damage in vivo and in vitro.

The Protective Effect of Sheep Placental Extract on Concanavalin A-induced Liver Injury in Mice

Though the biological effects of human placental extract have been widely studied, it has limited availability and its use poses ethical problems. Thus, domestic animal placental extracts are suggested as alternatives. In this study, the protective effect of sheep placental extract (SPE) on concanavalin A (Con A)-induced liver injury was investigated. BALB/c mice were randomly divided into six groups, including one normal group and five experimental groups, which received different oral doses of SPE (0, 5, 10 and 50 mg/kg) or a mixture of amino acids for 3 days before Con A injection. Compared with Con A-induced model group, the SPE administration significantly decreased serum aminotransaminase activity, alleviated pathological changes, recovered liver antioxidant capacity and prevented the increase of nitric oxide. Secretion of pro-inflammatory cytokines in serum decreased and mRNA expression of hepatic intercellular adhesion molecule-1, interferon-inducible chemokine 10 and inducible nitric oxide synthase were downregulated, while B-cell lymphoma-2 expression increased. The administration of amino acids mixture had no significant effect in most measurements compared with the model group, which indicated proteins and peptides, rather than individual amino acid, were largely responsible for the bioactivity of SPE. The results indicate SPE has potential therapeutic effects against immune-mediated hepatitis.

The Pharmacological Targets and Clinical Evidence of Natural Products With Anti-hepatic Inflammatory Properties

Inflammation contributes heavily to the pathogenesis of liver fibrosis, cirrhosis, and even hepatocellular carcinoma. Inflammation is probably a promising target for treatment of liver diseases. The natural products are considered as the potential source of new drug discovery and their pharmacological effects on hepatic inflammation have been widely reported. In this review, the natural products with anti-hepatic inflammatory properties are summarized based on their pharmacological effects and mechanisms, which are related to the suppression on the inflammation mediators including cytokines and chemokines, pattern recognition receptors, the activated transcriptional factors, and the potential regulatory factors. The clinical evidence is also summarized.

Protective effects of a traditional Chinese herbal formula Jiang-Xian HuGan on Concanavalin A-induced mouse hepatitis via NF-κB and Nrf2 signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Jiang-Xian HuGan (JXHG) formulated by five natural products including Freshwater clam (Corbicula fluminea), Curcuma longa L., Ligustrum lucidum, Eclipta prostrata (L.) L. and Paeonia lactiflora Pall., has exhibited a great hepatoprotective effect.

AIM OF THIS STUDY

We investigated the effect of JXHG on concanavalin A (ConA)-induced acute live injury in mice, and to elucidate its underlying molecular mechanisms.

MATERIALS AND METHODS

Jiangkanling Capsule (900 mg/kg), low-dose JXHG (LJXHG, 700 mg/kg), high-dose JXHG (HJXHG, 1400 mg/kg) were administered to mice by oral gavage daily for 20 days prior to a single intravenous injection of ConA (20 mg/kg). Liver injury was evaluated by measuring the serum levels of enzymes and cytokines as well as liver histological analysis. We also measured the hepatic expression of cytokines at mRNA levels and the proteins related to NF-κB and Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) signaling pathways.

RESULT

Our results showed that JXHG pretreatment significantly alleviated ConA-induced live injury as evidenced by decreased serum levels of glutamic-pyruvic transaminase (ALT) and glutamic oxalacetic transaminase (AST), and reduced hepatocyte apoptosis and mortality. Furthermore, JXHG was able to significantly reduce the serum levels of proinflammatory cytokines, down-regulate the mRNA expression of interleukin-6 (IL-6) and interferon-γ (IFN-γ), and up-regulate IL-10 as well as superoxide-dimutase-1 (SOD1), glutathione reductase (GSR) and Glutathione peroxidase 2 (GPX2) mRNA in the liver tissues after Con A injection. In addition, JXHG pretreatment dramatically suppressed the phosphorylation of NF-κB p65 (p65), increased Nrf2 expression, and decreased the expression ratio of cleaved caspase-3/caspase-3 in liver tissues.

CONCLUSION

These results suggest that JXHG protects against ConA-induced acute live injury through inhibiting NF-κB mediated inflammatory pathway and promoting Nrf2 mediated anti-oxidative stress signaling pathway.

Herbal remedies for liver fibrosis: A review on the mode of action of fifty herbs

Liver fibrosis is a dynamic pathological condition which can be slowed down in its initial phases. Without proper clinical management of fibrosis, progressive liver damage may lead to cirrhosis and ultimately to liver failure or primary liver cancer, which are irreversible conditions. Therefore, in order to cure fibrotic damage to liver, its early stages should be the centre of attention. In this context, some supplements and ‘complementary and alternative medicine (CAM)’ deserve specific mention, because of their already recognized natural way of healing and long lasting curative effects. Moreover, CAM display negligible side effects and hence it is gaining worldwide importance in clinical practices. In particular, herbal medicines are now replacing synthetic pharmaceuticals and looked upon as the sources of novel bioactive substances. To develop satisfactory herbal combinations for treating liver fibrosis, phytoproducts need to be systematically evaluated for their potency as anti-fibrotic, anti-hepatotoxic and antioxidant agents. More importantly, the identified herb/agent should have the remarkable tendency to stimulate hepatocytes regeneration. The present review is a systematic account of at least fifty medicinal herbs and their products which in experimental models have demonstrated antifibrotic activity and thus, most likely candidates to offer therapeutic protection to liver. Nevertheless, much additional work is still needed to explore molecular pathways to discover potential applications of these medicines so as to open up new vistas in biomedical research.

Curcumin attenuates lipopolysaccharide/d-galactosamine-induced acute liver injury by activating Nrf2 nuclear translocation and inhibiting NF-kB activation

Curcumin, a polyphenol in curry spice isolated from the rhizome of turmeric, has been reported to possess versatile biological properties including anti-inflammatory, anti-oxidant, antifibrotic, and anticancer activities. In this study, the hepatoprotective effect of curcumin was investigated in lipopolysaccharide (LPS)/d-galactosamine (d-GalN)-induced acute liver injury (ALI) in rats. Experimental ALI was induced with an intraperitoneal (ip) injection of sterile 0.9% sodium chloride (NaCl) solution containing 8μg LPS and 800mg/kg d-GalN. Curcumin was administered once daily starting three days prior to LPS/d-GalN treatment. Results indicated that curcumin could attenuate hepatic pathological damage, decrease serum ALT and AST levels, and reduce malondialdehyde (MDA) content in experimental ALI rats. Moreover, higher dosages of curcumin pretreatment inhibited NF-κB activation and reduced serum TNF-α and liver TNF-α levels induced by LPS/d-GalN ip injection. Furthermore, we found that curcumin up-regulated the expression of nuclear Nrf2 and Nrf2-dependent antioxidant defense genes including heme oxygenase-1 (HO-1), glutamate-cysteine ligase (GCLC), NAD(P)H dehydrogenase, and quinone (NQO-1) in a dose-dependent manner. Our results showed that curcumin protected experimental animals against LPS/d-GalN-induced ALI through activation of Nrf2 nuclear translocation and inhibition of NF-κB activation.

Curcumin Protects Against Intestinal Origin Endotoxemia in Rat Liver Cirrhosis by Targeting PCSK9

Intestinal origin endotoxemia always occurs in severe liver injury. The aim of the current study was to test antiendotoxemia effect of curcumin on tetrachloride (CCl₄ )-induced liver cirrhosis rats, and to elucidate the underlying molecular mechanism. Rat cirrhosis models were constructed with CCl₄ subcutaneous injections with curcumin (200 mg/kg/d) administered via gavages for 12 wk until the rats were sacrificed. We found that the administration of curcumin improved the physiological condition pertaining to activity index and temperature, and ameliorated the liver injury in CCl₄ -induced cirrhosis rats. Enzyme-linked immunosorbent assay (ELISA) and real-time quantitative polymerase chain reaction (qRT-PCR) showed that curcumin could reduce c-reaction protein levels and inflammatory cytokine (TNF-α, IL-1β, IL-6, and CINC-1/IL-8) concentrations in peripheral serum and liver tissue. Furthermore, curcumin treatment decreased lipopolysaccharide (LPS) levels in peripheral vein, but not in portal vein. As low-density lipoprotein receptor (LDLR) is the important receptor on the surface of hepatocyte during LPS detoxification process, we used qRT-PCR, western blot, and immunohistochemistry (IHC), finding that curcumin significantly increased LDLR protein levels, but not gene levels in the liver tissues. We also tested proprotein convertase subtilisin/kexin type 9 (PCSK9), one negative regulator of LDLR, by qRT-PCR, western blot, and IHC. The results showed that PCSK9 significantly decreased both gene and protein levels in the rat liver tissues of curcumin treatment. Thus, we concluded that curcumin could function to protect against intestinal origin endotoxemia by inhibiting PCSK9 to promote LDLR expression, thereby enhancing LPS detoxification as one pathogen lipid through LDLR in the liver.

Combined treatment with MSC transplantation and neutrophil depletion ameliorates D-GalN/LPS-induced acute liver failure in rats

BACKGROUND

The imbalance of immunity is an important pathogenesis of acute liver failure (ALF). Neutrophils are the hallmark of acute inflammation, which have an essential role in immune regulation. Mesenchymal stem cell (MSC) transplantation is a promising therapy in ALF treatment. Recent studies indicated a considerable connection between MSCs and neutrophils in immune regulation.

AIM

To investigate changes in neutrophils in ALF rats after MSC transplantation, and to explore the therapeutic effect and mechanism of the combined treatment with MSC transplantation and neutrophil depletion in ALF.

METHODS

We employed monotherapy and the combination therapy with MSCs and anti-PMN serum in D-galactosamine (D-GalN)/lipopolysaccharides (LPS)-induced ALF rats. Rats were sacrificed at 6, 12 and 24h, respectively. Blood samples and liver tissues were collected. Hepatic injury, inflammatory cytokines (TNF-α, IL-1β and IL-10), chemokines (CXCL1 and CXCL2), the number and activity of neutrophils and animal survival were assessed at fixed times.

RESULTS

MSC transplantation can effectively improve the liver function of ALF rats and reduce the number and activity of neutrophils in both peripheral blood and liver. Compared with MSC transplantation alone, anti-PMN treatment and co-treatment had a better result in diminishing neutrophils. The co-treatment also exhibited a better therapeutical effect in ALF rats compared with monotherapy. In this process, the expressions of inflammatory cytokines in the liver were consistent with liver function.

CONCLUSIONS

The regulation of the neutrophil-related microenvironment is affected in D-GalN/LPS-induced ALF rats after MSC transplantation. The combined treatment with MSC transplantation and neutrophil depletion may have a better therapeutic effect in ALF rats.

Hepatoprotective role of vardenafil against experimentally induced hepatitis in mice

Vardenafil is a selective phosphodiesterase-5 inhibitor used for erectile dysfunction treatment. The hepatoprotective role of vardenafil against acute hepatitis is not reported yet. Hence, this study aims to explore the protective role of vardenafil against concanavalin A (Con A) induced acute liver injury. Mice were pretreated with vardenafil (0.17 mg/kg/day) for seven consecutive days, and then subjected to a single IV injection of Con A. The results demonstrated that the vardenafil pretreatment significantly reduced the elevated serum levels of transaminases and alkaline phosphatase. Histopathological examination showed marked necrosis and inflammation in Con A-treated mice which was significantly ameliorated in vardenafil pretreated animals. Vardenafil pretreatment significantly alleviated the expression of nuclear factor kappa-B and inducible nitric oxide synthase in the hepatic tissue. Additionally, serum levels of nitric oxide and tumor necrosis factor-alpha were decreased in vardenafil pretreated animals compared to the Con A group. Therefore, our results demonstrate that vardenafil has hepatoprotective effect and this could be linked to decrease inflammatory mediators.

Protective Effects of Dracocephalum heterophyllum in ConA-Induced Acute Hepatitis

Dracocephalum heterophyllum (DH) is a Chinese herbal medicine used in treating hepatitis. However, the protective effects and pharmacological mechanisms of DH in hepatitis are unknown. In this study, we found that pretreatment with DH extract significantly ameliorated liver injury and suppressed the production of inflammatory cytokines, including tumor necrosis factor (TNF-α) and interferon-γ (IFN-γ) in Concanavalin A- (ConA-) induced hepatitis (CIH). DH recruited more CD11b⁺ Gr1⁺ myeloid-derived suppressor cells (MDSCs) to the liver and suppressed infiltration of macrophages (Kupffer cells) in the liver. The present work explores DH as an effective hepatoprotective medicine to inhibit inflammation and liver injury caused by hepatitis.

Augmenter of liver regeneration (ALR) restrains concanavalin A-induced hepatitis in mice

Augmenter of liver regeneration (ALR), produced and released by hepatocytes, has cytoprotective and immunoregulatory effects on liver injury, and has been used in many experimental applications. However, little attention has been paid to the effects of ALR on concanavalin A (Con A)-induced hepatitis. The purpose of this paper is to explore the protective effect of ALR on Con A-induced hepatitis and elucidate potential mechanisms. We found that the ALR pretreatment evidently reduced the amount of ALT and AST in serum. In addition, pro-inflammatory cytokines, chemokines and iNOS were suppressed. ALR pretreatment also decreased CD4(+), CD8(+) T cell infiltration in liver. Besides, we observed that ALR pretreatment was capable of suppressing the activation of several signaling pathways in Con A-induced hepatitis. These findings suggest that ALR can obviously weaken Con A-induced hepatitis and ALR has some certain immune regulation function.

Effects of curcumin on growth performance, jejunal mucosal membrane integrity, morphology and immune status in weaned piglets challenged with enterotoxigenic Escherichia coli

The aim of this study was to evaluate the effect of dietary curcumin supplementation on growth performance and intestinal mucosal barrier function of weaned piglets. Fifty piglets, weaned at 21±2 days of age, were randomly allotted to five treatments for 21 days. The dietary treatments were the control (basal diet), and the basal diet supplemented with 50mg/kg quinocetone, or 200 mg/kg, 300 mg/kg or 400mg/kg curcumin. The piglets were housed in individual pens and orally challenged with enterotoxigenic Escherichia coli (ETEC) during the preliminary trial period. The jejunal morphology and histology analysis were detected under light microscope. The plasma D-lactate and diamine oxidase (DAO) were determined by using enzymatic spectrophotometric assay. Immunohistochemistry assays were used to examine secretory immunoglobulin (sIgA) protein expression. Real-time PCR was used to determine mRNA levels of cytokine and Toll-like receptor 4 (TLR4) in jejunal mucosa. The results showed that, compared with the control, dietary addition of 300 mg/kg or 400 mg/kg curcumin decreased (P<0.05) feed/gain ratio and crypt depth, improved (P<0.05) villus height and villus height:crypt depth ratio, reduced (P<0.05) plasma D-lactate and DAO activity, up-regulated the protein expression of sIgA (P<0.05), increased (P<0.05) the number of goblet cells (GCs) and reduced (P<0.05) the number of intraepithelial lymphocytes (IELs). The mRNA levels of interleukin 1β (IL-1β) and TLR4 and tumor necrosis factor α (TNF-α) were also decreased (P<0.05), but mRNA level of interleukin 10 (IL-10) was increased (P<0.05). There was no difference in the above parameters between the 300 mg/kg and 400 mg/kg curcumin groups. Pigs fed with 50 mg/kg quinocetone also decreased (P<0.05) feed/gain ratio, increased villus height:crypt depth ratio (P<0.05), and reduced (P<0.05) crypt depth and mRNA levels of TLR4. In conclusion, curcumin and the quinocetone have similar effects in improving piglet growth, but dietary addition of 300 mg/kg or 400 mg/kg curcumin was more effective than quinocetone in improving intestinal mucosal barrier integrity, morphology, and immune status of weaned pigs. This indicates that curcumin could be used as a potential feed additive replacing quinocetone in weaned piglets.

Liver fibrosis and mechanisms of the protective action of medicinal plants targeting inflammation and the immune response

Inflammation is a central feature of liver fibrosis as suggested by its role in the activation of hepatic stellate cells leading to extracellular matrix deposition. During liver injury, inflammatory cells are recruited in the injurious site through chemokines attraction. Thus, inflammation could be a target to reduce liver fibrosis. The pandemic trend of obesity, combined with the high incidence of alcohol intake and viral hepatitis infections, highlights the urgent need to find accessible antifibrotic therapies. Medicinal plants are achieving popularity as antifibrotic agents, supported by their safety, cost-effectiveness, and versatility. The aim of this review is to describe the role of inflammation and the immune response in the pathogenesis of liver fibrosis and detail the mechanisms of inhibition of both events by medicinal plants in order to reduce liver fibrosis.

Protective effects of astaxanthin on ConA-induced autoimmune hepatitis by the JNK/p-JNK pathway-mediated inhibition of autophagy and apoptosis

OBJECTIVE

Astaxanthin, a potent antioxidant, exhibits a wide range of biological activities, including antioxidant, atherosclerosis and antitumor activities. However, its effect on concanavalin A (ConA)-induced autoimmune hepatitis remains unclear. The aim of this study was to investigate the protective effects of astaxanthin on ConA-induced hepatitis in mice, and to elucidate the mechanisms of regulation.

MATERIALS AND METHODS

Autoimmune hepatitis was induced in in Balb/C mice using ConA (25 mg/kg), and astaxanthin was orally administered daily at two doses (20 mg/kg and 40 mg/kg) for 14 days before ConA injection. Levels of serum liver enzymes and the histopathology of inflammatory cytokines and other maker proteins were determined at three time points (2, 8 and 24 h). Primary hepatocytes were pretreated with astaxanthin (80 μM) in vitro 24 h before stimulation with TNF-α (10 ng/ml). The apoptosis rate and related protein expression were determined 24 h after the administration of TNF-α.

RESULTS

Astaxanthin attenuated serum liver enzymes and pathological damage by reducing the release of inflammatory factors. It performed anti-apoptotic effects via the descending phosphorylation of Bcl-2 through the down-regulation of the JNK/p-JNK pathway.

CONCLUSION

This research firstly expounded that astaxanthin reduced immune liver injury in ConA-induced autoimmune hepatitis. The mode of action appears to be downregulation of JNK/p-JNK-mediated apoptosis and autophagy.

Protective effects of N-acetylcysteine in concanavalin A-induced hepatitis in mice

This study was designed to study the protective effects and mechanisms of N-acetylcysteine (NAC) in concanavalin A-induced hepatitis in mice. In this study, pretreatment with NAC ameliorated the histopathological changes and suppressed inflammatory cytokines in ConA-induced hepatitis. The expression of IL-2, IL-6, TNF-α, and IFN-γ was significantly reduced in the NAC-treated groups. NAC activated PI3K/Akt pathway and inhibited the activation of NF-κB. Additionally, NAC reduced autophagosome formation, as assessed by detecting the expression of LC3 and Beclin 1. Our results demonstrate that NAC can alleviate ConA-induced hepatitis by regulating the PI3K/Akt pathway and reducing the late stages of autophagy. Our results described a new pharmaceutical to provide more effective therapies for immune hepatitis.

Curcumin promotes KLF5 proteasome degradation through downregulating YAP/TAZ in bladder cancer cells

KLF5 (Krüppel-like factor 5) plays critical roles in normal and cancer cell proliferation through modulating cell cycle progression. In this study, we demonstrated that curcumin targeted KLF5 by promoting its proteasome degradation, but not by inhibiting its transcription in bladder cancer cells. We also demonstrated that lentivirus-based knockdown of KLF5 inhibited cancer cell growth, while over-expression of a Flag-tagged KLF5 could partially reverse the effects of curcumin on cell growth and cyclin D1 expression. Furthermore, we found that curcumin could down-regulate the expression of Hippo pathway effectors, YAP and TAZ, which have been reported to protect KLF5 protein from degradation. Indeed, knockdown of YAP by small interfering RNA caused the attenuation of KLF5 protein, but not KLF5 mRNA, which was reversed by co-incubation with proteasome inhibitor. A xenograft assay in nude mice finally proved the potent inhibitory effects of curcumin on tumor growth and the pro-proliferative YAP/TAZ/KLF5/cyclin D1 axis. Thus, our data indicates that curcumin promotes KLF5 proteasome-dependent degradation through targeting YAP/TAZ in bladder cancer cells and also suggests the therapeutic potential of curcumin in the treatment of bladder cancer.

Salidroside attenuates concanavalin A-induced hepatitis via modulating cytokines secretion and lymphocyte migration in mice

Salidroside, isolated from the medicinal plant Rhodiola, was reported to serve as an “adaptogen.” This study was designed to explore the protective effect of salidroside on concanavalin A- (Con A-) induced hepatitis in mice and investigate potential mechanisms. C57BL/6 mice were randomly divided into control group, Con A group, and salidroside group. Salidroside (50 mg/kg) was injected intravenously followed by Con A administration. The levels of ALT, AST, inflammatory cytokines and CXCL-10 were examined. The pathological damage of livers was assessed, the amounts of phosphorylated IκBα and p65 were measured, and the numbers of CD4⁺ and CD8⁺ T lymphocytes in the blood, spleen and infiltrated in the liver were calculated. Our results showed that salidroside pretreatment reduced the levels of ALT, AST dramatically and suppressed the secretion of proinflammatory cytokines through downregulating the activity of NF-κB partly. Salidroside altered the distribution of CD4⁺ and CD8⁺ T lymphocyte in the liver and spleen through regulating CXCL-10 and decreased the severity of liver injuries. In conclusion, these results confirm the efficacy of salidroside in the prevention of immune mediated hepatitis in mice.

Curcumin protects against concanavalin A-induced hepatitis in mice through inhibiting the cytoplasmic translocation and expression of high mobility group box 1

The aims of this study were to examine the anti-inflammatory effect of curcumin on concanavalin A (ConA) induced hepatitis in mice, and to elucidate its underlying molecular mechanisms. Mice received curcumin by gavage before ConA intravenous administration. The results showed that curcumin pretreatment attenuated ConA-induced hepatitis. Enzyme linked immunosorbent assay (ELISA) results showed that serum levels of high mobility group box 1 (HMGB1) increased at 4 h and reached its peak value at 12 h after challenge with ConA; but this increase was significantly inhibited by curcumin. Furthermore, curcumin significantly decreased the HMGB1 translocation from nucleus to cytoplasm of hepatocytes in ConA-induced mice. The levels of HMGB1 mRNA and protein expression in the liver were also significantly lowered in curcumin-treated mice. In addition, curcumin inhibited intrahepatic expression of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6 protein. In conclusion, the results indicated that curcumin protected against ConA-induced hepatitis in mice; and the beneficial effects may be partly through inhibition of HMGB1 translocation in hepatocytes, release into the plasma and expression in livers.

Inhibition by curcumin of multiple sites of the transforming growth factor-beta1 signalling pathway ameliorates the progression of liver fibrosis induced by carbon tetrachloride in rats

Background

At present there is no effective and accepted therapy for hepatic fibrosis. Transforming growth factor (TGF)-β1 signaling pathway contributes greatly to hepatic fibrosis. Reducing TGF-β synthesis or inhibiting components of its complex signaling pathway represent important therapeutic targets. The aim of the study was to investigate the effect of curcumin on liver fibrosis and whether curcumin attenuates the TGF-β1 signaling pathway.

Methods

Sprague–Dawley rat was induced liver fibrosis by carbon tetrachloride (CCl₄) for six weeks together with or without curcumin, and hepatic histopathology and collagen content were employed to quantify liver necro-inflammation and fibrosis. Moreover, the mRNA and protein expression levels of TGF-β1, Smad2, phosphorylated Smad2, Smad3, Smad7 and connective tissue growth factor (CTGF) were determined by quantitative real time-PCR, Western blot, or immunohistochemistry.

Results

Rats treated with curcumin improved liver necro-inflammation, and reduced liver fibrosis in association with decreased α-smooth muscle actin expression, and decreased collagen deposition. Furthermore, curcumin significantly attenuated expressions of TGFβ1, Smad2, phosphorylated Smad2, Smad3, and CTGF and induced expression of the Smad7.

Conclusions

Curcumin significantly attenuated the severity of CCl₄-induced liver inflammation and fibrosis through inhibition of TGF-β1/Smad signalling pathway and CTGF expression. These data suggest that curcumin might be an effective antifibrotic drug in the prevention of liver disease progression.

Curcumin inhibits Rift Valley fever virus replication in human cells

Rift Valley fever virus (RVFV) is an arbovirus that is classified as a select agent, an emerging infectious virus, and an agricultural pathogen. Understanding RVFV-host interactions is imperative to the design of novel therapeutics. Here, we report that an infection by the MP-12 strain of RVFV induces phosphorylation of the p65 component of the NFκB cascade. We demonstrate that phosphorylation of p65 (serine 536) involves phosphorylation of IκBα and occurs through the classical NFκB cascade. A unique, low molecular weight complex of the IKK-β subunit can be observed in MP-12-infected cells, which we have labeled IKK-β2. The IKK-β2 complex retains kinase activity and phosphorylates an IκBα substrate. Inhibition of the IKK complex using inhibitors impairs viral replication, thus alluding to the requirement of an active IKK complex to the viral life cycle. Curcumin strongly down-regulates levels of extracellular infectious virus. Our data demonstrated that curcumin binds to and inhibits kinase activity of the IKK-β2 complex in infected cells. Curcumin partially exerts its inhibitory influence on RVFV replication by interfering with IKK-β2-mediated phosphorylation of the viral protein NSs and by altering the cell cycle of treated cells. Curcumin also demonstrated efficacy against ZH501, the fully virulent version of RVFV. Curcumin treatment down-regulated viral replication in the liver of infected animals. Our data point to the possibility that RVFV infection may result in the generation of novel versions of host components (such as IKK-β2) that, by virtue of altered protein interaction and function, qualify as unique therapeutic targets.

Protective effects of curcumin against hepatic fibrosis induced by carbon tetrachloride: modulation of high-mobility group box 1, Toll-like receptor 4 and 2 expression

The aim of the study was to investigate the effect of curcumin on the liver fibrosis induced by carbon tetrachloride (CCl(4)) in rats, and to elucidate its underlying molecular mechanisms. Rats were administered with CCl(4) together with or without curcumin for 6 weeks. Hepatic damage was evaluated by analysis of liver function tests in serum. Hepatic histopathology and collagen content were employed to quantify liver fibrosis; and activated hepatic stellate cells were assessed. Moreover, the mRNA and protein expression levels of interleukin (IL)-6, tumor necrosis factor (TNF)-α, monocyte chemotactic protein (MCP)-1, high-mobility group box 1 (HMGB1), Toll like receptor (TLR) 2 and TLR4 were determined by quantitative real time PCR, Western blot or immunohistochemistry. Treatment with curcumin significantly attenuated CCl(4)-induce liver injury, hepatic inflammation and reduced the levels of proinflammatory mediators (TNF-α, IL-6 and MCP-1). Moreover, curcumin significantly inhibited extracellular matrix deposition, reduced the number of activated stellate cells, and decreased the levels of HMGB1, TLR4 and TLR2 expression in the rat model of fibrogenesis. These results suggest that curcumin could be an effective agent for preventing liver fibrosis and its mechanism may in part be a consequence of the reduction TLR2, TLR4 and HMGB1 expression.

Curcumin attenuates Concanavalin A-induced liver injury in mice by inhibition of Toll-like receptor (TLR) 2, TLR4 and TLR9 expression

Curcumin has antiviral, antioxidant, and anti-inflammatory properties. However, the hepatoprotective effects and molecular mechanisms of curcumin on acute liver injury have not been carefully examined. The aims of this study were to examine the anti-inflammatory effect of curcumin on Concanavalin A (Con A) induced hepatitis, and to elucidate its underlying molecular mechanisms in mice. Mice received curcumin (200 mg/kg body weight) by gavage before Con A intravenous administration. We found that curcumin pretreatment was able to significantly reduce the elevated plasma aminotransferase levels and liver necrosis in Con A-induced hepatitis. Also, curcumin pretreatment reduced intrahepatic expression of genes encoding pro-inflammatory molecules such as tumor necrosis factor α (TNF-α) and interferon γ (IFN-γ) as compared with the vehicle controls, but augmented anti-inflammatory cytokine interleukin 10 (IL-10) by enzyme linked immunosorbent assay (ELISA). Furthermore, the expression levels of Toll-like receptor (TLR) 2, TLR4 and TLR9 mRNA or protein in liver tissues were significantly lowered by curcumin treatment. Curcumin pretreatment did not affect hepatic Kupffer cell numbers after Con A injection. These results suggest that curcumin pretreatment protects against T cell-mediated hepatitis in mice. The beneficial effect of curcumin may be partly mediated by inhibiting the expression levels of TLR2, TLR4 and TLR9 in the liver.