Inhibition of concanavalin A-induced mice hepatitis by coumarin derivatives

Imperatorin Restores Chemosensitivity of Multidrug-Resistant Cancer Cells by Antagonizing ABCG2-Mediated Drug Transport

The high expression of the ATP-binding cassette (ABC) drug transporter ABCG2 in cancer cells contributes to the emergence of multidrug resistance (MDR) in individuals afflicted with either solid tumors or blood cancers. MDR poses a major impediment in the realm of clinical cancer chemotherapy. Recently, substantial endeavors have been dedicated to identifying bioactive compounds isolated from nature capable of counteracting ABCG2-mediated MDR in cancer cells. Imperatorin, a natural coumarin derivative renowned for its diverse pharmacological properties, has not previously been explored for its impact on cancer drug resistance. This study investigates the chemosensitizing potential of imperatorin in ABCG2-overexpressing cancer cells. Experimental results reveal that at sub-toxic concentrations, imperatorin significantly antagonizes the activity of ABCG2 and reverses ABCG2-mediated MDR in a concentration-dependent manner. Furthermore, biochemical data and in silico analysis of imperatorin docking to the inward-open conformation of human ABCG2 indicate that imperatorin directly interacts with multiple residues situated within the transmembrane substrate-binding pocket of ABCG2. Taken together, these results furnish substantiation that imperatorin holds promise for further evaluation as a potent inhibitor of ABCG2, warranting exploration in combination drug therapy to enhance the effectiveness of therapeutic agents for patients afflicted with tumors that exhibit high levels of ABCG2.

Coumarins and Gastrointestinal Cancer: A New Therapeutic Option?

Cancers of the gastrointestinal (GI) tract are often life-threatening malignancies, which can be a severe burden to the health care system. Globally, the mortality rate from gastrointestinal tumors has been increasing due to the lack of adequate diagnostic, prognostic, and therapeutic measures to combat these tumors. Coumarin is a natural product with remarkable antitumor activity, and it is widely found in various natural plant sources. Researchers have explored coumarin and its related derivatives to investigate their antitumor activity, and the potential molecular mechanisms involved. These mechanisms include hormone antagonists, alkylating agents, inhibitors of angiogenesis, inhibitors of topoisomerase, inducers of apoptosis, agents with antimitotic activity, telomerase inhibitors, inhibitors of human carbonic anhydrase, as well as other potential mechanisms. Consequently, drug design and discovery scientists and medicinal chemists have collaborated to identify new coumarin-related agents in order to produce more effective antitumor drugs against GI cancers. Herein, we summarize the therapeutic effects of coumarin and its derivatives against GI cancer.

Osthole Attenuates Macrophage Activation in Experimental Asthma by Inhibitingthe NF-ĸB/MIF Signaling Pathway

Inhibition of activated macrophages is an alternative therapeutic strategy for asthma. We investigated whether a coumarin compound, osthole, isolated from Cnidium monnieri (L.) Cuss, alleviated macrophage activation in vivo and in vitro. Osthole could reduce expression of a marker of activated macrophages, cluster of differentiation (CD)206, in an ovalbumin-challenge model of asthma in mice. Osthole could also inhibit infiltration of inflammatory cells, collagen deposition and production of proinflammatory cytokines [interleukin (IL)-1β, tumor necrosis factor-ɑ, macrophage migration inhibitory factor (MIF)] in asthmatic mice. In vitro, expression of phosphorylated-IĸBɑ, MIF and M2 cytokines (Ym-1, Fizz-1, arginase-1) in IL-4-induced macrophages decreased upon exposure to the NF-ĸB inhibitor MG-132. In our short hairpin (sh)RNA-MIF-knockdown model, reduced expression of M2 cytokines was detected in the IL-4 + shRNA-MIF group. Osthole could attenuate the proliferation and migration of an IL-4-induced rat alveolar macrophages line (NR8383). Osthole could reduce IL-4-induced translocation of nuclear factor-kappa B (NF-ĸB) in NR8383 cells. Collectively, our results suggest that osthole ameliorates macrophage activation in asthma by suppressing the NF-ĸB/MIF signaling pathway, and might be a potential agent for treating asthma.

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.

BRG1 Mediates Nephronectin Activation in Hepatocytes to Promote T Lymphocyte Infiltration in ConA-Induced Hepatitis

Fulminant hepatitis (FH) is a major cause of acute liver failure. Concanavalin A (ConA) belongs to the lectin family and is frequently used as an inducer of FH in animal models. ConA induced FH is characterized by massive accumulation of T lymphocytes in the liver. A host of chemoattractive substances are known to promote T cell homing to the liver during acute hepatitis. Here we investigated the involvement of Brahma-related gene 1 (BRG1), a chromatin remodeling protein, in FH. BRG1-flox mice were crossed to Alb-Cre mice to generate hepatocyte conditional BRG1 knockout (LKO) mice. The mice were peritoneally injected with a single dose of ConA to induce FH. BRG1 deficiency mitigated ConA-induced FH in mice. Consistently, there were fewer T lymphocyte infiltrates in the LKO livers compared to the wild type (WT) livers paralleling downregulation of T cell specific cytokines. Further analysis revealed that BRG1 deficiency repressed the expression of several chemokines critical for T cell homing including nephronectin (Npnt). BRG1 knockdown blocked the induction of Npnt in hepatocytes and attenuated T lymphocyte migration in vitro, which was reversed by the addition of recombinant nephronectin. Mechanistically, BRG1 interacted with β-catenin to directly bind to the Npnt promoter and activate Npnt transcription. Importantly, a positive correlation between infiltration of CD3⁺ T lymphocyes and nephronectin expression was detected in human acute hepatitis biopsy specimens. In conclusion, our data identify a novel role for BRG1 as a promoter of T lymphocyte trafficking by activating Npnt transcription in hepatocytes. Targeting the BRG1-Npnt axis may yield novel therapeutic solutions for FH.

Lung injury induced by pyrrolizidine alkaloids depends on metabolism by hepatic cytochrome P450s and blood transport of reactive metabolites

Pyrrolizidine alkaloids (PAs) are common phytotoxins with both hepatotoxicity and pneumotoxicity. Hepatic cytochrome P450 enzymes are known to bioactivate PAs into reactive metabolites, which can interact with proteins to form pyrrole-protein adducts and cause intrahepatic cytotoxicity. However, the metabolic and initiation biochemical mechanisms underlying PA-induced pneumotoxicity remain unclear. To investigate the in vivo metabolism basis for PA-induced lung injury, this study used mice with conditional deletion of the cytochrome P450 reductase (Cpr) gene and resultant tissue-selective ablation of microsomal P450 enzyme activities. After oral exposure to monocrotaline (MCT), a pneumotoxic PA widely used to establish animal lung injury models, liver-specific Cpr-null (LCN) mice, but not extrahepatic Cpr-low (xh-CL) mice, had significantly lower level of pyrrole-protein adducts in the serum, liver and lungs compared with wild-type (WT) mice. While MCT-exposed LCN mice had significantly higher blood concentration of intact MCT, compared to MCT-exposed WT or xh-CL mice. Consistent with the MCT in vivo bioactivation data, MCT-induced lung injury, represented by vasculature damage, in WT and xh-CL mice but not LCN mice. Furthermore, reactive metabolites of MCT were confirmed to exist in the blood efflux from the hepatic veins of MCT-exposed rats. Our results provide the first mode-of-action evidence that hepatic P450s are essential for the bioactivation of MCT, and blood circulating reactive metabolites of MCT to the lung causes pneumotoxicity. Collectively, this study presents the scientific basis for the application of MCT in animal lung injury models, and more importantly, warrants public awareness and further investigations of lung diseases associated with exposure to not only MCT but also different PAs.

Osthole, a Natural Plant Derivative Inhibits MRGPRX2 Induced Mast Cell Responses

Mast cells are tissue-resident innate immune cells known for their prominent role in mediating allergic reactions. MAS-related G-protein coupled receptor-X2 (MRGPRX2) is a promiscuous G-protein coupled receptor (GPCR) expressed on mast cells that is activated by several ligands that share cationic and amphipathic properties. Interestingly, MRGPRX2 ligands include certain FDA-approved drugs, antimicrobial peptides, and neuropeptides. Consequently, this receptor has been implicated in causing mast cell-dependent pseudo-allergic reactions to these drugs and chronic inflammation associated with asthma, urticaria and rosacea in humans. In the current study we examined the role of osthole, a natural plant coumarin, in regulating mast cell responses when activated by the MRGPRX2 ligands, including compound 48/80, the neuropeptide substance P, and the cathelicidin LL-37. We demonstrate that osthole attenuates both the early (Ca2+ mobilization and degranulation) and delayed events (chemokine/cytokine production) of mast cell activation via MRGPRX2 in vitro. Osthole also inhibits MrgprB2- (mouse ortholog of human MRGPRX2) dependent inflammation in in vivo mouse models of pseudo-allergy. Molecular docking analysis suggests that osthole does not compete with the MRGPRX2 ligands for interaction with the receptor, but rather regulates MRGPRX2 activation via allosteric modifications. Furthermore, flow cytometry and confocal microscopy experiments reveal that osthole reduces both surface and intracellular expression levels of MRGPRX2 in mast cells. Collectively, our data demonstrate that osthole inhibits MRGPRX2/MrgprB2-induced mast cell responses and provides a rationale for the use of this natural compound as a safer alternative treatment for pseudo-allergic reactions in humans.

Osthole induces cell cycle arrest and apoptosis in head and neck squamous cell carcinoma by suppressing the PI3K/AKT signaling pathway

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is one of the most common lethal tumors with a high recurrence rate and low survival rate. Therefore, an urgent need exists for novel and effective treatment strategies for HNSCC patients.

METHODS

Osthole, a natural ingredient extracted from Cnidium monnieri (L.) 'Cusson', has multiple pharmacological effects including antineoplastic activity. Regrettably, the antineoplastic effect of osthole in HNSCC cells remains undefined. We utilize in vitro assays to assess the anti-proliferative effects of osthole in HNSCC cells and tumorigenesis assays using FaDu cells in murine HNSCC models to assess in vivo function. Moreover, the possible molecular mechanisms of Osthole on HNSCC cells was also investigated.

RESULTS

Our findings show that the anti-proliferation effect of osthole might function through induction of cell cycle arrest (G2/M phase) and apoptosis in HNSCC. Osthole could also down-regulating the protein level of cell cycle and apoptosis related proteins, such as Bcl-2, PARP1, Survivin, CyclinB1 and Cdc2, while up-regulating expression of Cleaved Caspase3/9, Cleaved PARP1 and Bax. Similarly, osthole suppressed the in vivo growth of FaDu cells in a subcutaneous tumor model. In terms of mechanism, our data show that osthole can suppress the PI3K/AKT pathway.

CONCLUSIONS

In the current study, our in vitro and in vivo assay showed the suppressive effect of Osthole on HNSCC cells through induce cell cycle arrest (G2/M phase) and apoptosis. Moreover, the action mechanisms of Osthole on proliferation related signaling pathways was disclosed. Our present study suggests that osthole might be used as an effective therapeutic agent for patients with HNSCC.

Imperatorin improves in vitro porcine embryo development by reducing oxidative stress and autophagy

Imperatorin (IMP), a furanocoumarin derivative with many biological properties and pharmacological activities, is widely used as an antibacterial, anti-inflammatory, antiviral, anticancer, cardiovascular and neuroprotective agent. The purpose of this study was to explore the effects of IMP on early embryo development in pigs as well as the potential mechanisms. Our results showed that IMP can enhance the developmental competence of porcine early embryos. Supplementation of in vitro culture medium with 40 μM IMP significantly increased the blastocyst rate and total cell number. At the same time, apoptosis of blastocysts was also significantly decreased in the supplemented group compared with the control group, in accordance with the subsequent results of FAS and CASP3 gene expression analysis. Furthermore, IMP attenuated intracellular reactive oxygen species (ROS) generation, increased fluorescein diacetate (FDA) and glutathione (GSH) levels. Importantly, IMP not only improved the activity of mitochondria but also inhibited the occurrence of autophagy. In addition, pluripotency-related genes (OCT4, NANOG, and SOX2) and a growth and metabolism regulatory gene (mTOR) were upregulated after IMP supplementation on Day 7. These results demonstrate that IMP exerts a beneficial effect on preimplantation embryo development by reducing oxidative stress and autophagy.

Inhibitory Effects of Osthole on Human Breast Cancer Cell Progression via Induction of Cell Cycle Arrest, Mitochondrial Dysfunction, and ER Stress

BACKGROUND

Breast cancer is the most commonly diagnosed cancer and the second leading cause of cancer death in women. Although, recently, the number of pathological studies of breast cancer have increased, it is necessary to identify a novel compound that targets multiple signaling pathways involved in breast cancer.

METHODS

The effects of osthole on cell viability, apoptosis, mitochondria-mediated apoptosis, production of reactive oxygen species (ROS), and endoplasmic reticulum (ER) stress proteins of BT-474 and MCF-7 breast cancer cell lines were investigated. Signal transduction pathways in both cells in response to osthole were determined by western blot analyses.

RESULTS

Here, we demonstrated that osthole inhibited cellular proliferation and induced cell cycle arrest through modulation of cell cycle regulatory genes in BT-474 and MCF-7 cells. Additionally, osthole induced loss of mitochondrial membrane potential (MMP), intracellular calcium imbalance, and ER stress. Moreover, osthole induced apoptosis by activating the pro-apoptotic protein, Bax, in both cell lines. Osthole regulated phosphorylation of signaling proteins such as Akt and ERK1/2 in human breast cancer cells. Furthermore, osthole-induced activation of JNK protein-mediated apoptosis in both cell lines.

CONCLUSIONS

Collectively, the results of the present study indicated that osthole may ameliorate breast cancer and can be a promising therapeutic agent for treatment of breast cancer.

Osthole prevents tamoxifen-induced liver injury in mice

Tamoxifen (TMX) is an antiestrogen drug that is used in the treatment and prevention of all stages of estrogen-dependent breast cancer. Adverse effects of TMX include hepatotoxicity. In this study, we investigated the therapeutic effects of osthole, isolated from medicinal plants especially Fructus Cnidii, on TMX-induced acute liver injury in mice. Mice were injected with osthole (100 mg/kg, ip) or vehicle, followed by TMX (90 mg/kg, ip) 24 h later. We showed that a single injection of TMX-induced liver injury and oxidative stress. Pretreatment with osthole attenuated TMX-induced liver injury evidenced by dose-dependent reduction of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities. Pretreatment with osthole also blunted TMX-induced oxidative stress, evidenced by significant increase of reduced glutathione (GSH) as well as reduction of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂). Consistently, osthole significantly enhanced the expressions of antioxidant genes (GPX1, SOD2, GCL-c, and G6pdh), but suppressed those of pro-oxidant genes (NOX2 and ACOX). Furthermore, osthole inhibited the production of inflammatory cytokines, reduced the metabolic activation of TMX, and promoted its clearance. We further revealed that osthole elevated hepatic cAMP and cGMP levels, but inhibition of PKA or PKG failed to abolish the hepatoprotective effect of osthole. Meanwhile, prominent phosphorylation of p38 was observed in liver in response to TMX, which was significantly inhibited by osthole. Pretreatment with SB203580, a p38 inhibitor, significantly attenuated TMX-induced increase of ALT and AST activities, reduced oxidative stress, and reversed the alterations of gene expression caused by TMX. Moreover, pretreatment with L-buthionine sulfoximine (BSO), an inhibitor of GSH synthesis, partly reversed the effect of osthole on TMX-induced liver injury. Consistently, pretreatment with N-acetyl-L-cysteine (NAC) significantly attenuated TMX-induced increase in ALT and AST activities. Notably, both BSO and NAC had no detectable effect on the phosphorylation levels of p38. Collectively, our results suggest that osthole prevents TMX hepatotoxicity by suppressing p38 activation and subsequently reducing TMX-induced oxidative damage.

Osthole induces human nasopharyngeal cancer cells apoptosis through Fas-Fas ligand and mitochondrial pathway

Nasopharyngeal carcinoma (NPC) is endemic in Southern China and Southeast Asia. The present study investigated the activity of osthole in suppressing NPC along with the underlying mechanism. Cell growth inhibition was measured using the MTT assay. Apoptosis was detected through 4',6-diamidino-2-phenylindole staining and flow cytometry. Western blotting was used to identify the signaling pathway. Osthole markedly inhibited cell proliferation and induced apoptosis in the NPC cell line. Western blotting results revealed the increased activation of caspases 3, 8, and 9 and poly (ADP-ribose) polymerase. Osthole treatment significantly reduced the expression of the antiapoptotic protein Bcl-2 and increased the expression of the proapoptotic proteins Bax, Bak, BimL, BimS, and t-Bid. Osthole treatment also increased the expression of Fas, FADD, TNF-R1, TNF-R2, DcR2, RIP, and DR5. In addition, osthole treatment significantly increased the expression levels of phosphorylated ERK1/2 and JNK1/2. These results suggested that osthole exerts cytotoxic effects on NPC cell lines mainly through apoptosis mediated by the Fas-Fas ligand and mitochondrial pathway. Osthole could be a potential anticancer agent for NPC.

Role of Elevated Fibrinogen in Burn-Induced Mitochondrial Dysfunction: Protective Effects of Glycyrrhizin

INTRODUCTION

Skeletal muscle wasting and weakness with mitochondrial dysfunction (MD) are major pathological problems in burn injury (BI) patients. Fibrinogen levels elevated in plasma is an accepted risk factor for poor prognosis in many human diseases, and is also designated one of damage-associated molecular pattern (DAMPs) proteins. The roles of upregulated fibrinogen on muscle changes of critical illness including BI are unknown. The hypothesis tested was that BI-upregulated fibrinogen plays a pivotal role in the inflammatory responses and MD in muscles, and that DAMPs inhibitor, glycyrrhizin mitigates the muscle changes.

METHODS

After third degree BI to mice, fibrinogen levels in the plasma and at skeletal muscles were compared between BI and sham-burn (SB) mice. Fibrinogen effects on inflammatory responses and mitochondrial membrane potential (MMP) loss were analyzed in C2C12 myotubes. In addition to survival, the anti-inflammatory and mitochondrial protective effects of glycyrrhizin were tested using in vivo microscopy of skeletal muscles of BI and SB mice.

RESULTS

Fibrinogen in plasma and its extravasation to muscles significantly increased in BI versus SB mice. Fibrinogen applied to myotubes evoked inflammatory responses (increased MCP-1 and TNF-α; 32.6 and 3.9-fold, respectively) and reduced MMP; these changes were ameliorated by glycyrrhizin treatment. In vivo MMP loss and superoxide production in skeletal muscles of BI mice were significantly attenuated by glycyrrhizin treatment, together with improvement of BI survival rate.

CONCLUSIONS

Inflammatory responses and MMP loss in myotubes induced by fibrinogen were reversed by glycyrrhizin. Anti-inflammatory and mitochondrial protective effect of glycyrrhizin in vivo leads to amelioration of muscle MD and improvement of BI survival rate.

Osthole prevents acetaminophen-induced liver injury in mice

Acetaminophen (APAP) overdose leads to severe hepatotoxicity. Osthole, a natural coumarin found in traditional Chinese medicinal herbs, has therapeutic potential in the treatment of various diseases. In this study, we investigated the effects of osthole against APAP-induced hepatotoxicity in mice. Mice were administered osthole (100 mg·kg^-1·d^-1, ip) for 3 d, then on the fourth day APAP (300 mg/kg, ip) was co-administered with osthole. The mice were euthanized post-APAP, their serum and livers were collected for analysis. Pretreatment with osthole significantly attenuated APAP-induced hepatocyte necrosis and the increases in ALT and AST activities. Compared with the mice treated with APAP alone, osthole pretreatment significantly reduced serum MDA levels and hepatic H₂O₂ levels, and improved liver GSH levels and the GSSG-to-GSH ratio. Meanwhile, osthole pretreatment markedly alleviated the APAP-induced up-regulation of inflammatory cytokines in the livers, and inhibited the expression of hepatic cytochrome P450 enzymes, but it increased the expression of hepatic UDP-glucuronosyltransferases (UGTs) and sulfotransferases (SULTs). Furthermore, osthole pretreatment reversed APAP-induced reduction of hepatic cAMP levels, but pretreatment with H89, a potent selective PKA inhibitor, failed to abolish the beneficial effect of osthole, whereas pretreatment with L-buthionine sulfoximine, a GSH synthesis inhibitor, abrogated the protective effects of osthole on APAP-induced liver injury, and abolished osthole-caused alterations in APAP-metabolizing enzymes. In cultured murine primary hepatocytes and Raw264.7 cells, however, osthole (40 μmol/L) did not alleviate APAP-induced cell death, but it significantly suppressed APAP-caused elevation of inflammatory cytokines. Collectively, we have demonstrated that osthole exerts a preventive effect against APAP-induced hepatotoxicity by inhibiting the metabolic activation of APAP and enhancing its clearance through an antioxidation mechanism.

Anti-asthmatic activity of osthole in an ovalbumin-induced asthma murine model

Osthole, an active coumarin extracted from the dried fruits of Cnidium monnieri (L.) Cusson, is known to possess a variety of pharmacological activities. In the present study, we investigated and illuminated the mechanisms underlying the protective effects of osthole in an experimental model of allergic asthma. Our results show that osthole treatment significantly reduced the OVA-induced increase in serum IgE and inflammatory cytokines (IL-4, IL-5, IL-13) in bronchoalveolar lavage fluid (BALF), and decreased the recruitment of inflammatory cells in BALF and the lung. It also effectively attenuated goblet cell hyperplasia and mucus overproduction in lung tissue. In addition, western blot analysis demonstrated that osthole blocked NF-κB activation, which may be associated with a reduction in inflammatory cytokine production. These data suggest that osthole attenuated OVA-induced allergic asthma inflammation by inhibiting NF-κB activation. The present study identified the molecular mechanisms of action of osthole, which support the potential pharmaceutical application of osthole treatment for asthma and other airway inflammation disorders.

Influence of coumarin and some coumarin derivatives on serum lipid profiles in carbontetrachloride-exposed rats

In the present study, coumarin and some coumarin derivatives (esculetin, scoparone, and 4-methylumbelliferone) were investigated for their lipid-lowering effect in rats. Male Sprague–Dawley rats (150–200 g) were divided into six groups and each group comprised of five rats. Hepatic injury-dependent hyperlipidemia was induced by carbon tetrachloride (CCl4, 1.25 ml/kg). Coumarin and coumarin derivatives esculetin (35 mg/kg), scoparone (35 mg/kg), 4-methylumbelliferone (35 mg/kg), or coumarin (30 mg/kg) were administered to experimental groups at 12-h intervals. Animals received the derivatives esculetin, scoparone or 4-methylumbelliferone prior to the administration of a single toxic dose of CCl4. Serum total cholesterol (TC), triglyceride (TG), very low-density lipoprotein cholesterol (VLDL-C), and low-density lipoprotein cholesterol (LDL-C) levels significantly increased in CCl4-treated group ( p < 0.05, p < 0.01, p < 0.01, and p < 0.05, respectively), while levels of serum high-density lipoprotein cholesterol (HDL-C) decreased ( p < 0.01). 4-Methylumbelliferone had no recovery effects on serum TC levels, however, significantly prevented CCl4-induced hyperlipidemia by reducing TG and VLDL-C levels ( p < 0.05 and p < 0.05, respectively). In addition, coumarin had no recovery effect on any of the serum lipid parameters against CCl4-induced hyperlipidemia. Among the coumarin derivatives only esculetin and scoparone significantly prevented serum HDL-C in CCl4-induced dyslipidemia. The results from this study indicate that the chemical structure of coumarins plays an important role on the regulation of serum lipid profiles.

Imperatorin-pharmacological meaning and analytical clues: profound investigation

Imperatorin, a furanocoumarin derivative, has many documented pharmacological properties which make it a candidate for possible drug development. In this review, the activity on the central nervous system, the anticancer and antiviral properties and the influence on the cardiovascular system are described. The aim of this review is also to present an overview of the techniques used for the analysis, isolation, and separation of imperatorin from plant material from the practical perspective.

Osthole confers neuroprotection against cortical stab wound injury and attenuates secondary brain injury

Background

Neuroendoscopy is an innovative technique for neurosurgery that can nonetheless result in traumatic brain injury. The accompanying neuroinflammation may lead to secondary tissue damage, which is the major cause of delayed neuronal death after surgery. The present study investigated the capacity of osthole to prevent secondary brain injury and the underlying mechanism of action in a mouse model of stab wound injury.

Methods

A mouse model of cortical stab wound injury was established by inserting a needle into the cerebral cortex for 20 min to mimic neuroendoscopy. Mice received an intraperitoneal injection of osthole 30 min after surgery and continued for 14 days. Neurological severity was evaluated 12 h and up to 21 days after the trauma. Brains were collected 3–21 days post-injury for histological analysis, immunocytochemistry, quantitative real-time PCR, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and enzyme-linked immunosorbent assays.

Results

Neurological function improved in mice treated with osthole and was accompanied by reduced brain water content and accelerated wound closure relative to untreated mice. Osthole treatment reduced the number of macrophages/microglia and peripheral infiltrating of neutrophils and lowered the level of the proinflammatory cytokines interleukin-6 and tumor necrosis factor α in the lesioned cortex. Osthole-treated mice had fewer TUNEL+ apoptotic neurons surrounding the lesion than controls, indicating increased neuronal survival.

Conclusions

Osthole reduced secondary brain damage by suppressing inflammation and apoptosis in a mouse model of stab wound injury. These results suggest a new strategy for promoting neuronal survival and function after neurosurgery to improve long-term patient outcome.

Osthole: A Review on Its Bioactivities, Pharmacological Properties, and Potential as Alternative Medicine

This paper reviews the latest understanding of biological and pharmacological properties of osthole (7-methoxy-8-(3-methyl-2-butenyl)-2H-1-benzopyran-2-one), a natural product found in several medicinal plants such as Cnidium monnieri and Angelica pubescens. In vitro and in vivo experimental results have revealed that osthole demonstrates multiple pharmacological actions including neuroprotective, osteogenic, immunomodulatory, anticancer, hepatoprotective, cardiovascular protective, and antimicrobial activities. In addition, pharmacokinetic studies showed osthole uptake and utilization are fast and efficient in body. Moreover, the mechanisms of multiple pharmacological activities of osthole are very likely related to the modulatory effect on cyclic adenosine monophosphate (cAMP) and cyclic adenosine monophosphate (cGMP) level, though some mechanisms remain unclear. This review aims to summarize the pharmacological properties of osthole and give an overview of the underlying mechanisms, which showcase its potential as a multitarget alternative medicine.

Osthole promotes anti-tumor immune responses in tumor-bearing mice with hepatocellular carcinoma

Osthole, a natural coumarin derivative, has been shown to have anti-tumor and anti-inflammatory activity. However, the effect of osthole on anti-tumor immune responses in tumor-bearing mice has not yet been reported. In the present study, osthole treatment did not affect the weight and the coefficient of thymus and spleen in tumor-bearing mice with hepatocellular carcinoma (HCC). However, osthole administration significantly elevated the proportion and number of the splenic CD8(+) T cells, the proportion of CD4(+) T and CD8(+) T cells in tumor tissues, and the levels of IL-2 and TNF-α in the serum of HCC tumor-bearing mice. Our results suggested that osthole could promote the activation of the tumor-infiltrating CD4(+) T and CD8(+) T cells, and elevate the proportion of CD4(+) and CD8(+) effector T cells. Osthole treatment also significantly decreased the proportion of CD4(+)CD25(+)Foxp3(+) regulatory T cells in the spleen. Taken together, osthole could enhance the T cell mediated anti-tumor immune responses in the tumor-bearing mice with HCC.

Protective effect of ellagic acid on concanavalin A-induced hepatitis via toll-like receptor and mitogen-activated protein kinase/nuclear factor κB signaling pathways

Ellagic acid (EA) is present in certain fruits and nuts, including raspberries, pomegranates, and walnuts, and has anti-inflammatory and antioxidant properties. The aims of this study were to examine the protective effect of EA on concanavalin A (Con A)-induced hepatitis and to elucidate its underlying molecular mechanisms in mice. Mice were orally administered EA at different doses before the intravenous delivery of Con A; the different experimental groups were as follows: (i) vehicle control, (ii) Con A alone without EA, (iii) EA at 50 mg/kg, (iv) EA at 100 mg/kg, and (v) EA at 200 mg/kg. We found that EA pretreatment significantly reduced the levels of plasma aminotransferase and liver necrosis in Con A-induced hepatitis. Also, EA significantly decreased the expression levels of the toll-like receptor 2 (TLR2) and TLR4 mRNA and protein in liver tissues. Further, EA decreased the phosphorylation of JNK, ERK1/2, and p38. EA-treated groups showed suppressions of nuclear factor κB (NF-κB) and IκB-α degradation levels in liver tissues. In addition, EA pretreatment decreased the expression of pro-inflammatory cytokines, such as tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), and interleukin 1β (IL-1β). These results suggest that EA protects against T-cell-mediated hepatitis through TLR and mitogen-activated protein kinase (MAPK)/NF-κB signaling pathways.

Osthole augments therapeutic efficiency of neural stem cells-based therapy in experimental autoimmune encephalomyelitis

The therapeutic potential of adult neural stem cells (NSCs)-derived from bone marrow (BM) has been recently described in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis; however, the beneficial effects are modest due to their marginal anti-inflammatory capacity. To overcome this weakness and endow BM-NSC therapy with profound anti-inflammatory capacity, in this study we pretreated EAE mice with osthole, a natural coumarin with a broad spectrum of pharmacological activities, including anti-inflammation, immunomodulation, and neuroprotection, before NSC-application and continued throughout the study. We found that osthole conferred a potent anti-inflammatory capacity to this BM-NSC therapy, thus more profoundly suppressing ongoing EA and exhibiting significant advantages over conventional NSC-therapy as follows: 1) Enhanced anti-inflammatory effect, thus improving survival environment for engrafted BM-NSCs and protecting myelin sheaths from further demyelination; 2)Drove transplanted (exogenous) BM-NSCs to differentiate into more oligodendrocytes and neurons but inhibited differentiation into astrocytes, thus promoting remyelination and axonal growth, and reducing astrogliosis; and 3) augmented CNS neurotrophic support thus promoted resident (endogenous) repair of myelin/axonal damage. These effects make the BM-NSCs-based therapy a more promising approach to enhance remyelination and neuronal repopulation, thus more effectively promoting anatomic and functional recovery from neurological deficits.

Osthole inhibits proliferation of human breast cancer cells by inducing cell cycle arrest and apoptosis

Recent studies have revealed that osthole, an active constituent isolated from the fruit of Cnidium monnieri (L.) Cusson, a traditional Chinese medicine, possesses anticancer activity. However, its effect on breast cancer cells so far has not been elucidated clearly. In the present study, we evaluated the effects of osthole on the proliferation, cell cycle and apoptosis of human breast cancer cells MDA-MB 435. We demonstrated that osthole is effective in inhibiting the proliferation of MDA-MB 435 cells, The mitochondrion-mediated apoptotic pathway was involved in apoptosis induced by osthole, as indicated by activation of caspase-9 and caspase-3 followed by PARP degradation. The mechanism underlying its effect on the induction of G1 phase arrest was due to the up-regulation of p53 and p21 and down-regulation of Cdk2 and cyclin D1 expression. Were observed taken together, these findings suggest that the anticancer efficacy of osthole is mediated via induction of cell cycle arrest and apoptosis in human breast cancer cells and osthole may be a potential chemotherapeutic agent against human breast cancer.

Osthole relaxes pulmonary arteries through endothelial phosphatidylinositol 3-kinase/Akt-eNOS-NO signaling pathway in rats

Pulmonary arterial hypertension is a life-threatening disease lacking effective therapies. Osthole is a natural coumarin compound isolated from Angelica pubescens Maxim., which possesses hypotensive effect. Although its effects on isolated thoracic aorta (systemic circulating system) are clarified, it remains unclear whether Osthole relaxes isolated pulmonary arteries (PAs) (pulmonary circulating system). The aim of this study was to investigate the effects of Osthole on isolated PAs and the underlying mechanisms. We examined PA relaxation induced by Osthole in isolated human and rat PA rings with force-electricity transducers, the expression and activity of endothelial nitric oxide synthase (eNOS) and protein kinase B (Akt) with western blot, and nitric oxide (NO) production using DAF-FM DA fluorescent indicator. The results showed that Osthole elicited a dose-dependent vasorelaxation activity with phenylephrine-precontracted human and rat PA rings, which can be diminished by endothelium denudation and inhibition of eNOS, while having no effect on rat mesenteric arteries. Osthole increased NO release as well as activation of Akt and eNOS, indicated with increased phosphorylations of Akt at Ser-473 and eNOS at Ser-1177 in endothelial cells. PI3K inhibitor LY294002 also blocked Osthole induced vasodilation. In summary, dilative effect of Osthole was dependent on endothelial integrity and NO production, and was mediated by endothelial PI3K/Akt-eNOS-NO pathway. These may provide a new pulmonary vasodilator for the therapy of pulmonary arterial hypertension.

Growth inhibition and apoptosis induced by osthole, a natural coumarin, in hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is one of the most commonly diagnosed tumors worldwide and is known to be resistant to conventional chemotherapy. New therapeutic strategies are urgently needed for treating HCC. Osthole, a natural coumarin derivative, has been shown to have anti-tumor activity. However, the effects of osthole on HCC have not yet been reported.

Methods and Findings

HCC cell lines were treated with osthole at various concentrations for 24, 48 and 72 hours. The proliferations of the HCC cells were measured by MTT assays. Cell cycle distribution and apoptosis were determined by flow cytometry. HCC tumor models were established in mice by subcutaneously injection of SMMC-7721 or Hepa1-6 cells and the effect of osthole on tumor growths in vivo and the drug toxicity were studied. NF-κB activity after osthole treatment was determined by electrophoretic mobility shift assays and the expression of caspase-3 was measured by western blotting. The expression levels of other apoptosis-related genes were also determined by real-time PCR (PCR array) assays. Osthole displayed a dose- and time-dependent inhibition of the HCC cell proliferations in vitro. It also induced apoptosis and caused cell accumulation in G2 phase. Osthole could significantly suppress HCC tumor growth in vivo with no toxicity at the dose we used. NF-κB activity was significantly suppressed by osthole at the dose- and time-dependent manner. The cleaved caspase-3 was also increased by osthole treatment. The expression levels of some apoptosis-related genes that belong to TNF ligand family, TNF receptor family, Bcl-2 family, caspase family, TRAF family, death domain family, CIDE domain and death effector domain family and CARD family were all increased with osthole treatment.

Conclusion

Osthole could significantly inhibit HCC growth in vitro and in vivo through cell cycle arrest and inducing apoptosis by suppressing NF-κB activity and promoting the expressions of apoptosis-related genes.

Inhibition of inflammation and oxidative stress by Angelica dahuricae radix extract decreases apoptotic cell death and improves functional recovery after spinal cord injury

Inflammation and oxidative stress play major roles in the pathogenesis after spinal cord injury (SCI). Here, we examined the neuroprotective effects of Angelica dahuricae radix (ADR) extract after SCI. ADR extract significantly decreased the levels of proinflammatory factors such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) in a lipopolysaccharide (LPS)-activated microglial cell line, BV2 cells. ADR extract also significantly alleviated the level of reactive oxygen species in LPS-activated BV2 cells. To examine the neuroprotective effect of ADR extract after SCI, spinally injured rats were administered ADR extract orally at a dose of 100 mg/kg for 14 days. ADR extract treatment significantly reduced the levels of TNF-α, IL-1β, IL-6, iNOS, and COX-2. The levels of superoxide anion (O(2·)(-)) and protein nitration were also significantly decreased by ADR extract. In addition, ADR extract inhibited p38 mitogen-activated protein kinase activation and pronerve growth factor expression in microglia after SCI. Furthermore, ADR extract significantly inhibited caspase-3 activation following apoptotic cell death of neurons and oligodendrocytes, thereby improving functional recovery after injury. Thus, our data suggest that ADR extract provides neuroprotection by alleviating inflammation and oxidative stress and can be used as an orally administered therapeutic agent for acute SCI.

Osthole induces G2/M arrest and apoptosis in lung cancer A549 cells by modulating PI3K/Akt pathway

Background

To explore the effects of Osthole on the proliferation, cell cycle and apoptosis of human lung cancer A549 cells.

Methods

Human lung cancer A549 cells were treated with Osthole at different concentrations. Cell proliferation was measured using the MTT assay. Cell cycle was evaluated using DNA flow cytometry analysis. Induction of apoptosis was determined by flow cytometry and fluorescent microscopy. The expressions of Cyclin B1, p-Cdc2, Bcl-2, Bax, t-Akt and p-Akt were evaluated by Western blotting.

Results

Osthole inhibited the growth of human lung cancer A549 cells by inducing G2/M arrest and apoptosis. Western blotting demonstrated that Osthole down-regulated the expressions of Cyclin B1, p-Cdc2 and Bcl-2 and up-regulated the expressions of Bax in A549 cells. Inhibition of PI3K/Akt signaling pathway was also observed after treating A549 cells with Osthole.

Conclusions

Our findings suggest that Osthole may have a therapeutic application in the treatment of human lung cancer.

Protective effects of coumarin and coumarin derivatives against carbon tetrachloride-induced acute hepatotoxicity in rats

The comparison of the antioxidant activity of some coumarins with their molecular structure is well determined. However, the protective function of coumarins with various chemical structures against liver toxicity has not yet been well established. Therefore, the aim of this study was to evaluate the possible cytoprotective properties of coumarin and some coumarin derivatives against CCl(4) (carbon tetrachloride)-induced hepatotoxicity. Coumarin (1,2-benzopyrone) and coumarin derivatives esculetin (6,7-dihydroxycoumarin), scoparone (6,7-dimethoxycoumarin) and 4-methylumbelliferone (7-hyroxy-4-methyl) were examined for their protective effect against CCl(4)-induced hepatotoxicity in Male Sprague-Dawley rats. A single toxic dose of CCl(4) (1.25 ml kg(-1), orally) produced liver damage in rats, seen histologically as centrilobular necrosis. Administration of CCl(4) increased serum enzyme levels of aspartate transaminase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP). Pre-treatment of rats with esculetin (31.15 mg kg(-1), orally) and scoparone (35 mg kg(-1), orally) significantly prevented CCl(4)-induced increase in serum enzymes, whereas 4-methylumbelliferone (35 mg kg(-1)) and coumarin (30 mg kg(-1)) had no effect against CCl(4)-induced rise in serum enzymes. Morphological findings were consistent with the plasma transaminase observations. Among the coumarin analogs, esculetin, which possesses orthodihydroxy coumarins, showed the strongest protective effect against CCl(4)-induced liver damage, followed by scoparone, 4-methylumbelliferone and coumarin, respectively. The results of this study indicate that the chemical structures of coumarins play an important role in the prevention of liver toxicity.

Attenuation of experimental autoimmune encephalomyelitis in C57 BL/6 mice by osthole, a natural coumarin

Osthole, a natural coumarin, is known to have a variety of pharmacological and biochemical uses and is considered to have potential therapeutic applications. Here we examined the effects of osthole on the central nervous system demyelination in experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis and its mechanism(s). C57 BL/6 mice immunized with myelin oligodendrocyte glycoprotein 35-55 amino acid peptide were treated with osthole at day 7 post immunization (7 p.i., subclinical periods, early osthole treatment) and day 13 p.i. (clinical periods, late osthole treatment) respectively and both therapies continued throughout the study. The content of nerve growth factor (NGF) and interferon gamma (IFN-gamma) in the sera and brain of mice in vivo as well as the splenocytes culture supernatants in vitro were detected. The results showed that osthole retarded the disease process when the therapy was initiated at subclinical periods, attenuated the clinical severity of EAE mice when the therapy was initiated at both subclinical and clinical periods, ameliorated inflammation and demyelination and improved the outcomes of magnetic resonance imaging. In addition, osthole blocked the reduction of NGF and suppressed IFN-gamma increase in EAE mice. These results suggested that osthole might be a new pharmacological approach to treat multiple sclerosis.

Imperatorin enhances the protective activity of conventional antiepileptic drugs against maximal electroshock-induced seizures in mice

The effects of imperatorin (8-isopentenyloxypsoralen; 9-(3-methylbut-2-enyloxy)-7H-furo[3,2-g]chromen-7-one) on the anticonvulsant activity of four conventional antiepileptic drugs (carbamazepine, phenobarbital, phenytoin and valproate) were studied in the mouse maximal electroshock seizure model. Results indicate that imperatorin (30 and 40 mg/kg, i.p.) significantly potentiated the anticonvulsant activity of carbamazepine against maximal electroshock-induced seizures by reducing its median effective dose (ED(50)) from 10.3 to 6.8 (by 34%; P<0.05) and 6.0 mg/kg (by 42%; P<0.01), respectively. Similarly, imperatorin (40 mg/kg, i.p.) markedly enhanced the antielectroshock action of phenobarbital and phenytoin, by lowering their ED(50) values from 19.6 to 12.2 mg/kg (by 38%; P<0.05-phenobarbital) and from 12.8 to 8.5 mg/kg (by 34%; P<0.05-phenytoin) in the maximal electroshock seizure test. In contrast, imperatorin (40 mg/kg, i.p.) did not affect the protective action of valproate against maximal electroshock-induced seizures in mice. Imperatorin at lower doses of 20 and 30 mg/kg had no significant effect on the anticonvulsant activities of conventional antiepileptic drugs in the mouse maximal electroshock seizure model. Pharmacokinetic evaluation of interaction between imperatorin (30 mg/kg, i.p.) and carbamazepine (6.8 mg/kg, i.p.) revealed a significant increase in total brain carbamazepine concentration after imperatorin administration, indicating a pharmacokinetic nature of interaction between these drugs. In cases of phenobarbital and phenytoin, imperatorin (40 mg/kg, i.p.) did not alter significantly total brain concentrations of phenytoin and phenobarbital in mice, and thus, the observed interactions in the maximal electroshock seizure test between imperatorin and phenobarbital or phenytoin were pharmacodynamic in nature. The present study demonstrates that imperatorin enhanced the antiseizure effects of carbamazepine, phenobarbital and phenytoin in the mouse maximal electroshock seizure model. However, the combination of imperatorin with carbamazepine, despite its beneficial effects in terms of seizure suppression in mice, was complicated by a pharmacokinetic increase in total brain carbamazepine concentration in experimental animals. In contrast, the combinations of imperatorin with phenytoin and phenobarbital, due to their beneficial antiseizure effects and no pharmacokinetic interactions between drugs in the brain compartment of experimental animals, deserve more attention and are of pivotal importance for epileptic patients as advantageous combinations from a clinical viewpoint.

Time–course and dose–response relationships of imperatorin in the mouse maximal electroshock seizure threshold model

This study was designed to evaluate the anticonvulsant effects of imperatorin (a furanocoumarin isolated from fruits of Angelica archangelica) in the mouse maximal electroshock seizure threshold model. The threshold for electroconvulsions in mice was determined at several times: 15, 30, 60 and 120 min after i.p. administration of imperatorin at increasing doses of 10, 20, 30, 40, 50 and 100 mg/kg. The evaluation of time-course relationship for imperatorin in the maximal electroshock seizure threshold test revealed that the agent produced its maximum antielectroshock action at 30 min after its i.p. administration. In this case, imperatorin at doses of 50 and 100 mg/kg significantly raised the threshold for electroconvulsions in mice by 38 and 68% (P<0.05 and P<0.001), respectively. The antiseizure effects produced by imperatorin at 15, 60 and 120 min after its systemic (i.p.) administration were less expressed than those observed for imperatorin injected 30 min before the maximal electroshock seizure threshold test. Based on this study, one can conclude that imperatorin produces the anticonvulsant effect in the maximal electroshock seizure threshold test in a dose-dependent manner.

Antitumor effects of Osthol from Cnidium monnieri: an in vitro and in vivo study

Cnidium monnieri (L.) Cusson is a Chinese medicine which is used widely by traditional medicine doctors. Osthol is a major bio-activity compound of the herb. In this study, osthol was isolated from C. monnieri and its in vitro and in vivo antitumor effects studied. The results of the in vitro study showed: that osthol inhibited the growth of HeLa, in a time- and concentration-dependent manner, with IC(50) values of 77.96 and 64.94 microm for 24 and 48 h, respectively; that osthol had lower cytotoxic effects in primary cultured normal cervical fibroblasts; and that increased DNA fragmentation and activated PARP in HeLa after treatment with osthol which could induce apoptosis. The results of the in vivo model showed that the survival days of the P-388 D1 tumor-bearing CDF(1) mice were prolonged (ILS% = 37) after osthol (30 mg/kg) was given once a day for 9 days. Based on these results, it is suggested that osthol could inhibit P-388 D1 cells in vivo and induce apoptosis in HeLa cells in vitro, and that osthol is good lead compound for developing antitumor drugs. However, C. formosanum Yabe of Taiwan's endemic plants contained little osthol, with no imperatorin, and its major components were different from that of C. monnieri. Therefore, it is suggested that C. formosanum also may possess economic worth.

Osthole prevents anti-Fas antibody-induced hepatitis in mice by affecting the caspase-3-mediated apoptotic pathway

Fas (Apo-1/CD95) ligand, which is a type II membrane protein, is a major inducer of apoptosis. Osthole is a coumarin derivative present in medicinal plants. The effect of osthole on hepatitis induced by anti-Fas antibody in mice was studied. Pretreatment of mice with osthole (10, 50, and 100 mg/kg, i.p.) prevented the elevation of plasma alanine aminotransferase (ALT) caused by anti-Fas antibody (175 microg/kg, i.v.). Administration of osthole to mice even at a dose of 10 mg/kg significantly inhibited of anti-Fas antibody-induced elevation of plasma ALT. Capase-3 is a cysteine protease, and treatment of mice with anti-Fas antibody caused an elevation of caspase-3 activity at 3.5 and 6 hr. Pretreatment of mice with osthole (100 mg/kg, i.p.) inhibited the elevation of caspase-3 activity caused by anti-Fas antibody. However, the addition of osthole (up to 10(-4)M) to a liver cytosol fraction isolated from mice treated with anti-Fas antibody did not inhibit caspase-3 activity in vitro. Thus, treatment of mice with osthole inhibited caspase-3 activity by an effect upstream of caspase-3 activation. The livers of mice treated with anti-Fas antibody contained apoptotic and dead cells; osthole attenuated the development of this apoptosis and cell death. The present results show that osthole prevented anti-Fas antibody-induced hepatitis by inhibiting the Fas-mediated apoptotic pathway.

Imperatorin, a furanocoumarin from Angelica dahurica (Umbelliferae), induces cytochrome c-dependent apoptosis in human promyelocytic leukaemia, HL-60 Cells

Imperatorin, a biologically active furanocoumarin from the roots of Angelica dahurica (Umbelliferae), was found to induce apoptosis in human promyelocytic leukaemia, HL-60 cells. DNA fragmentation assay, morphology-based evaluation, and flow cytometric analysis demonstrated that imperatorin at micromolar concentrations was able to trigger apoptosis of HL-60 cells. Neither necrosis nor differentiation was observed at cytotoxic micromolar concentrations of imperatorin. Further studies showed that the cytochrome c/caspase-9 pathway was responsible for imperatorin-induced apoptosis; i.e., mitochondrial membrane was depolarized, Bcl-2 was down-regulated, cytochrome c was released from mitochondria, caspase-9 and caspase-3 were activated, and poly(ADP-ribose) polymerase was cleaved. Furthermore, imperatorin-induced apoptosis was significantly blocked by Z-VAD-FMK (a broad spectrum caspase inhibitor), Z-LEHD-FMK (a caspase-9 inhibitor) and Ac-DMQD-CHO (a caspase-3 inhibitor), but not by Z-IEDT-FMK (a caspase-8 inhibitor).

Hepatoprotective drugs for the treatment of virus-induced chronic hepatitis: from hypercarcinogenic state to hypocarcinogenic state

Interferon (IFN)-based therapy is a standard treatment for chronic hepatitis caused by hepatitis C virus (HCV) infection. This treatment is effective in approximately 30-40% of the patients and using ribavirin in combination with IFN increases the rate of sustained virologic clearance. For the remaining patients, glycyrrhizin is often used. Glycyrrhizin is known to prevent the development of hepatocellular carcinoma (HCC), but glycyrrhizin is usually administered intravenously. Drugs that are effective by oral administration are convenient for patients for long-term administration, and development of more effective drugs than glycyrrhizin is preferable. However, studies on drugs for the treatment of hepatitis are not actively conducted, and promotion of the study of drugs in this area is encouraging. For that reason, we show our approach to study drugs for the treatment of hepatitis. We analyzed the effect of glycyrrhizin on hepatitis as a standard chemical using the mouse liver injury model. Based on this, we screened drugs and found that a coumarin derivative seems to be one of model chemicals for the treatment of hepatitis.