Scoparone attenuates d-galactosamine/lipopolysaccharide-induced fulminant hepatic failure through inhibition of toll-like receptor 4 signaling in mice

The immunoregulatory effects of scoparone on immune-mediated inflammatory diseases

Scoparone (SCO), also known as 6,7-Dimethoxycoumarin, is a naturally occurring bioactive ingredient originally derived from Chinese herb Artemisiae Scopariae Herba (Yin-Chen-Hao). Previous studies have shown that it is effective in treating some of the liver diseases. Beyond its hepatoprotective effects, an expanding body of research has underscored the immunoregulatory properties of SCO, indicating its potential therapeutic benefits for autoimmune and other inflammatory diseases. Over the past decade, significant advances have been made in understanding the mechanistic insights into its effects on immune-mediated diseases as well as liver diseases. SCO has an impact on various immune cells, including mast cells, monocytes, macrophages, neutrophils and T cells, and affects a broad range of intracellular signaling pathways, including TLR4/Myd88/NFκB, TGFβR/Smad3 and JNK/Sab/SHP-1 etc. Therefore, this review not only summarizes the immunomodulatory and therapeutic effects of SCO on immune-based inflammatory diseases (IMIDs), such as inflammatory bowel disease, osteoarthritis, allergic rhinitis, acute lung injury, type 1 diabetes and neuroinflammatory diseases etc., but also provides a comprehensive summary of its therapeutic effects on hepatic diseases, including non-alcoholic steatohepatitis, fulminant hepatic failure and hepatic fibrosis. In this review, we also include the broad impacts of SCO on intracellular signaling pathways, such as TLR4/Myd88/NFκB, TGFβR/Smad3, Nrf2/P38, JAK2/STAT3 and JNK/Sab/SHP-1 etc. Further researches on SCO may help understand its in-depth mechanisms of action and pave the way for the development of novel drugs to prevent and treat various immune-mediated inflammatory disorders as well as hepatic diseases, thereby significantly advancing its innovations and pharmaceutical applications.

Coumarins as versatile therapeutic phytomolecules: A systematic review

BACKGROUND

Coumarins, abundantly distributed in a plethora of biologically active compounds, serve as a fundamental motif in numerous natural products, drugs, and therapeutic leads. Despite their small size, they exhibit a diverse range of biological activities, intriguing researchers with their immense pharmacological potential.

PURPOSE

This study consolidates the evidence regarding the essential role of coumarins in modern drug discovery, exploring their broad-spectrum pharmaceutical effects, structural versatility, and mechanisms of action across various domains.

METHODS

For literature search, we utilized PubMed, Google scholar, and SciFinder databases. Keyword and keyword combinations such as "coumarins", "natural coumarins", "specific natural coumarins for particular diseases", and "therapeutic effects" were employed to retrieve relevant studies. The search encompassed articles published between 2005 and 2023. Selection criteria included studies reporting on the pharmacological activities of natural coumarins against various diseases.

RESULTS

The results highlight the therapeutic potential of natural coumarins against various diseases, demonstrating anti-cancer, anti-oxidant, and anti-inflammatory activities. They also act as monoamine oxidase inhibitors and phosphodiesterase inhibitors, and as anti-thrombotic, anti-diabetic, and hepatoprotective agents. They also show efficacy against diabetic nephropathy, neurodegenerative diseases, microbial infections and many other diseases.

CONCLUSION

This review underscores the significant role of natural coumarins in medicinal chemistry and drug discovery. Their diverse biological activities and structural versatility make them promising therapeutic agents. This study serves as a catalyst for further research in the field, aiming to address emerging challenges and opportunities in drug development.

Scoparone inhibits the development of hepatocellular carcinoma by modulating the p38 MAPK/Akt/NF-κB signaling in nonalcoholic fatty liver disease mice

BACKGROUND AND STUDY AIM

The mechanisms underlying the progression of non-alcoholic fatty liver disease (NAFLD) into hepatocellular carcinoma (HCC) remains confusing and the therapeutics approaches are also challenging. Here, we aimed to investigate the effects of scoparone on the treatment of HCC stemmed from NAFLD and the underlying mechanisms.

MATERIALS AND METHODS

A model of NAFLD-HCC was created in mice, and these mice were treated with scoparone. Biochemical assays were conducted to assess the levels of biochemical markers. Tumors were evaluated through morphological examination. Histopathological analyses were performed using oil red O, Hematoxylin and Eosin, and Masson coloration assays. Immunohistochemistry (IHC) and RT-PCR were performed to analyze protein expression and measure mRNA expression levels, respectively.

RESULTS

Scoparone could ameliorate the pathological alterations observed in NAFLD-HCC mouse model. IHC analysis indicated an upregulation of NF-κB p65 expression in both NAFLD and NAFLD-HCC models, which was subsequently reverted by scoparone administration. Furthermore, scoparone treatment resulted in a reversal of the increased mRNA expression levels of NF-κB target genes, including TNF-α, MCP-1, iNOS, COX-2, NF-κB, and MMP-9, which were originally elevated in the NAFLD-HCC condition. Additionally, scoparone exhibited a capacity to counteract the activation of the MAPK/Akt signaling in the NAFLD-HCC model.

CONCLUSION

These findings suggest that scoparone holds promise as a potential therapeutic agent for NAFLD-associated HCC, and its model of action may involve the regulation of inflammatory pathways governed by the MAPK/Akt/NF-κB signaling cascade.

Ligand-free high loading capacity ursolic acid self-carried nanovesicles enable hepatocyte targeting via absorbing apolipoproteins

Ursolic acid (UA), a natural pentacyclic terpenoid carboxylic acid that can exert a potent hepatoprotective activity, has been developed into various types of nanoparticles to improve its pharmacological effects, however, the phagocytosis of nanoparticles by Kupffer cells greatly limits its efficacy. Herein, UA/Tween 80 nanovesicles (V-UA) were constructed and despite its simple composition, it fulfills multiple functions simultaneously: UA served as not only an active ingredient in the nanovesicle drug delivery system, but also acts as part of the carrier to stabilize UA/Tween 80 nanostructure; with a molar ratio of UA to Tween 80 up to 2:1, the formulation possesses a significant advantage of higher drug loading capacity; relative to liposomal UA (Lipo-UA), a conditional cellular uptake and higher accumulation of V-UA in hepatocytes provide insights into the hepatocytes targeting mechanisms of this nanovesicles. Favorable hepatocyte targeting ability also facilitates the treatment of liver diseases, which was well validated in three liver disease models.

Quality Markers’ Discovery and Quality Evaluation of Jigucao Capsule Using UPLC-MS/MS Method

Jigucao capsules (JGCC) have the effects of soothing the liver and gallbladder and clearing heat and detoxification. It is a good medicine for treating acute and chronic hepatitis cholecystitis with damp heat of the liver and gallbladder. However, the existing quality standard of JGCC does not have content determination items, which is not conducive to quality control. In this study, serum pharmacochemistry technology and UNIFI data processing software were used to identify the blood prototype components and metabolites under the condition of the obvious drug effects of JGCC, and the referenced literature reports and the results from in vitro analysis of JGCC in the early stage revealed a total of 43 prototype blood components and 33 metabolites in JGCC. Quality markers (Q-markers) were discovered, such as abrine, trigonelline, hypaphorine and isoschaftoside. In addition, ultra-high-performance liquid chromatography–triple quadrupole mass spectrometry (UPLC-QQQ-MS) was used to determine the active ingredients in JGCC. The components of quantitative analysis have good correlation in the linear range with R2 ≥ 0.9993. The recovery rate is 93.15%~108.92% and the relative standard deviation (RSD) is less than 9.48%. The established UPLC-MS/MS quantitative analysis method has high sensitivity and accuracy, and can be used for the quality evaluation of JGCC.

Scoparone Improves Nonalcoholic Steatohepatitis Through Alleviating JNK/Sab Signaling Pathway-Mediated Mitochondrial Dysfunction

The activated c-Jun N-terminal kinase (JNK) specifically combined with SH3 domain-binding protein 5 (Sab) may mediate damage to the mitochondrial respiratory chain. Whether mitochondrial dysfunction induced by the JNK/Sab signaling pathway plays a pivotal role in the lipotoxic injury of nonalcoholic steatohepatitis (NASH) remains a lack of evidence. Scoparone, a natural compound from Traditional Chinese Medicine herbs, has the potential for liver protection and lipid metabolism regulation. However, the effect of scoparone on NASH induced by a high-fat diet (HFD) as well as its underlying mechanism remains to be elucidated. The HepG2 and Huh7 cells with/without Sab-knockdown induced by palmitic acid (PA) were used to determine the role of JNK/Sab signaling in mitochondrial dysfunction and cellular lipotoxic injury. To observe the effect of scoparone on the lipotoxic injured hepatocytes, different dose of scoparone together with PA was mixed into the culture medium of HepG2 and AML12 cells to incubate for 24 h. In addition, male C57BL/6J mice were fed with an HFD for 22 weeks to induce the NASH model and were treated with scoparone for another 8 weeks to investigate its effect on NASH. Molecules related to JNK/Sab signaling, mitochondrial function, and lipotoxic injury were detected in in vitro and/or in vivo experiments. The results showed that PA-induced activation of JNK/Sab signaling was blocked by Sab knockdown in hepatocytes, which improved mitochondrial damage, oxidative stress, hepatosteatosis, cell viability, and apoptosis. Scoparone demonstrated a similar effect on the PA-induced hepatocytes as Sab knockdown. For the NASH mice, treatment with scoparone also downregulated the activation of JNK/Sab signaling, improved histopathological changes of liver tissues including mitochondrial number and morphology, lipid peroxide content, hepatosteatosis and inflammation obviously, as well as decreased the serum level of lipid and transaminases. Taken together, this study confirms that activation of the JNK/Sab signaling pathway-induced mitochondrial dysfunction plays a crucial role in the development of NASH. Scoparone can improve the lipotoxic liver injury partially by suppressing this signaling pathway, making it a potential therapeutic compound for NASH.

Chinese medicine in the treatment of autoimmune hepatitis: Progress and future opportunities

Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease occurring in individuals of all ages with a higher incidence in females and characterized by hypergammaglobulinemia, elevated serum autoantibodies and histological features of interface hepatitis. AIH pathogenesis remains obscure and still needs in‐depth study, which is likely associated with genetic susceptibility and the loss of immune homeostasis. Steroids alone and in combination with other immunosuppressant agents are the primary choices of AIH treatment in the clinic, whereas, in some cases, severe adverse effects and disease relapse may occur. Chinese medicine used for the treatment of AIH has proven its merits over many years and is well tolerated. To better understand the pathogenesis of AIH and to evaluate the efficacy of novel therapies, several animal models have been generated to recapitulate the immune microenvironment of patients with AIH. In the current review, we summarize recent advances in the study of animal models for AIH and their application in pharmacological research of Chinese medicine‐based therapies and also discuss current limitations. This review aims to provide novel insights into the discovery of Chinese medicine‐originated therapies for AIH using cutting‐edge animal models.

Inhibitory effects of scoparone from chestnut inner shell on platelet-derived growth factor-BB-induced vascular smooth muscle cell migration and vascular neointima hyperplasia

BACKGROUND

Compounds of the inner shell of chestnut (Castanea crenata) have diverse biological activities, including anti-cancer and anti-oxidant activities. Here we explored the effects of an extract of chestnut inner shells and of its bioactive component scoparone on vascular smooth muscle cell migration and vessel damage.

RESULTS

The ethanol extract of chestnut inner shells, containing 11 major compounds, inhibited platelet-derived growth factor (PDGF)-BB-induced migration of rat aortic smooth muscle cells (RASMCs). Among these compounds, scoparone (6,7-dimethoxycoumarin) suppressed RASMC migration and wound healing in response to PDGF-BB but did not affect RASMC proliferation. In RASMCs, scoparone inhibited the PDGF-BB-induced rat aortic sprout outgrowth and attenuated the PDGF-BB-mediated increase in phosphorylation of mitogen-activated protein kinases (MAPKs), p38 MAPK and extracellular signal-regulated kinase 1/2. The in vivo administration of scoparone resulted in the attenuation of neointima formation in balloon-injured carotid arteries of rats.

CONCLUSION

These findings demonstrate that scoparone, found in chestnut inner shells, may inhibit cell migration through suppression of the phosphorylation of MAPKs in PDGF-BB-treated RASMCs, probably contributing to the reduction of neointimal hyperplasia induced after vascular injury. Therefore, scoparone and chestnut inner shell may be a potential agent or functional food, respectively, for the prevention of vascular disorders such as vascular restenosis or atherosclerosis. © 2019 Society of Chemical Industry.

Geraniol protects against lipopolysaccharide and D-galactosamine-induced fulminant hepatic failure by activating PPARγ

Geraniol (GOH), a natural component of plant essential oils, exhibits potent antioxidant and anti-inflammatory properties. The aim of this study was to assess the protective effects and mechanisms of GOH on lipopolysaccharide (LPS)/d-galactosamine (D-GalN)-induced fulminant hepatic failure (FHF). Mice were treated with GOH (12.5, 25, and 50 μg/kg) 1 h before challenging LPS (60 mg/kg) and D-GalN (800 mg/kg). 8 h later LPS/D-GlaN treatment, mice were sacrificed and the serum and the liver tissues were collected for testing. The liver pathological changes were assessed by H & E staining. MPO activity, MDA level in liver tissues, and AST, ALT levels in serum were detected by specific detection kits. The levels of TNF-α and IL-1β were detected by ELISA. The expression of NF-κB and PPARγ were detected by western blot analysis and qRT-PCR. The results showed that GOH had a protective effect on LPS/D-GalN-induced FHF, as evidence by the attenuation of liver pathological injury, MPO activity, MDA level, and serum AST and ALT levels. GOH reduced liver TNF-α and IL-1β levels through inhibiting NF-κB signaling pathway activation. Furthermore, GOH increased PPARγ expression in FHF induced by LPS/D-GalN. In conclusion, the present study proved that GOH protects against LPS/D-GalN-induced FHF through inhibiting inflammatory response and increasing PPARγ expression.

Hepatoprotective Effects of Kaempferol-3-O-α-l-Arabinopyranosyl-7-O-α-l-Rhamnopyranoside on d-Galactosamine and Lipopolysaccharide Caused Hepatic Failure in Mice

Fulminant hepatic failure (FHF), associated with high mortality, is characterized by extensive death of hepatocytes and hepatic dysfunction. There is no effective treatment for FHF. Several studies have indicated that flavonoids can protect the liver from different factor-induced injury. Previously, we found that the extracts of Elaeagnus mollis leaves had favorable protective effects on acute liver injury. However, the role and mechanisms behind that was elusive. This study examined the hepatoprotective mechanisms of kaempferol-3-O-α-l-arabinopyranosyl-7-O-α-l-rhamnopyra-noside (KAR), a major flavonol glycoside of E. mollis, against d-galactosamine (GalN) and lipopolysaccharide (LPS)-induced hepatic failure. KAR reduces the mouse mortality, protects the normal liver structure, inhibits the serum aspartate aminotransferase (AST) and alamine aminotransferase (ALT) activity and decreases the production of malondialdehyde (MDA) and reactive oxygen species (ROS) and inflammatory cytokines, TNF-α, IL-6, and IL-1β. Furthermore, KAR inhibits the apoptosis of hepatocytes and reduces the expression of TLR4 and NF-κB signaling pathway-related proteins induced by GalN/LPS treatment. These findings suggest that the anti-oxidative, anti-inflammatory, and anti-apoptotic effects of KAR on GalN/LPS-induced acute liver injury were performed through down-regulating the activity of the TLR4 and NF-κB signaling pathways.

Insight into the metabolic mechanism of scoparone on biomarkers for inhibiting Yanghuang syndrome

Scoparone (6,7-dimethoxycoumarin) is the representative ingredient of Yinchenhao (Artemisia capillaris Thunb.) which is a famous Chinese medicinal herb and shows favorable efficacy for all kinds of liver disease, specifically for the treatment of Yanghuang syndrome (YHS). The precise molecular mechanism concerning the action of scoparone on YHS is yet to be fully elucidated. The aim of the present study was to determine the mechanism of scoparone and evaluate its efficacy on metabolite levels. The differential expression of metabolites responsible for the pharmacological effects of scoparone was characterized and the protection effect of scoparone against this disease. Using multivariate statistical analysis, 33 biomarkers were identified using precise MS/MS and play an important role in the regulation of key metabolic pathways associated with liver disease. In addition, pathological results also showed consistent changes in the YHS model group and after treatment with scoparone, both the metabolic profile and histopathology resembled that of normal level, which suggesting favorable efficacy over the observed time period. The present work indicated that a metabolomics platform provided a new insight into understanding the mechanisms of action of natural medicines such as scoparone.

The therapeutic effect of CORM-3 on acute liver failure induced by lipopolysaccharide/D-galactosamine in mice

BACKGROUND

Acute liver failure (ALF) is a severe and life-threatening clinical syndrome resulting in a high mortality and extremely poor prognosis. Recently, a water-soluble CO-releasing molecule (CORM-3) has been shown to have anti-inflammatory effect. The present study was to investigate the effect of CORM-3 on ALF and elucidate its underlying mechanism.

METHODS

ALF was induced by a combination of LPS/D-GalN in mice which were treated with CORM-3 or inactive CORM-3 (iCORM-3). The efficacy of CORM-3 was evaluated based on survival, liver histopathology, serum aminotransferase activities (ALT and AST) and total bilirubin (TBiL). Serum levels of inflammatory cytokines (TNF-alpha, IL-6, IL-1beta and IL-10) and liver immunohistochemistry of NF-kappaB-p65 were determined; the expression of inflammatory mediators such as iNOS, COX-2 and TLR4 was measured using Western blotting.

RESULTS

The pretreatment with CORM-3 significantly improved the liver histology and the survival rate of mice compared with the controls; CORM-3 also decreased the levels of ALT, AST and TBiL. Furthermore, CORM-3 significantly inhibited the increased concentration of pro-inflammatory cytokines (TNF-alpha, IL-6 and IL-1beta) and increased the anti-inflammatory cytokine (IL-10) productions in ALF mice. Moreover, CORM-3 significantly reduced the increased expression of iNOS and TLR4 in liver tissues and inhibited the nuclear expression of NF-kappaB-p65. CORM-3 had no effect on the increased expression of COX-2 in the ALF mice. An iCORM-3 failed to prevent acute liver damage induced by LPS/D-GalN.

CONCLUSION

These findings provided evidence that CORM-3 may offer a novel alternative approach for the management of ALF through anti-inflammatory functions.

β-Caryophyllene alleviates D-galactosamine and lipopolysaccharide-induced hepatic injury through suppression of the TLR4 and RAGE signaling pathways

Agastache rugosa (A. rugosa, Labiatae), a perennial herb spread throughout Korean fields, is widely consumed as a wild edible vegetable and is used in folk medicine. This study examined the hepatoprotective mechanisms of β-caryophyllene (BCP), a major bicyclic sesquiterpene of A. rugosa, against D-galactosamine (GalN) and lipopolysaccharide (LPS)-induced hepatic failure. Mice were given an intraperitoneal injection of BCP (50, 100 and 200 mg/kg) 1 h before GalN (800 mg/kg)/LPS (40 μg/kg) injection and were killed 1 h or 6 h after GalN/LPS injection. GalN/LPS markedly increased mortality and serum aminotransferase activity, both of which were attenuated by BCP. BCP also attenuated increases in serum tumor necrosis factor-α, interleukin 6, and high-mobility group protein B1 levels by GalN/LPS. GalN/LPS significantly increased toll-like receptor (TLR) 4 and receptor for advanced glycation end products (RAGE) protein expression, extracellular signal-related kinase, p38 and c-Jun N-terminal kinase phosphorylation, nuclear factor κB (NF-κB), early growth response protein-1, and macrophage inflammatory protein-2 protein expression. These increases were attenuated by BCP. Furthermore, BCP suppressed increased TLR4 and RAGE protein expression and proinflammatory cytokines production in LPS-treated isolated Kupffer cells. Our findings suggest that BCP protects against GalN/LPS-induced liver injury through down-regulation of the TLR4 and RAGE signaling.

Protective effect of wild ginseng cambial meristematic cells on d-galactosamine-induced hepatotoxicity in rats

Background

Panax ginseng has a wide range of biological activities including anti-inflammatory, antioxidant, and immunomodulatory functions. Wild ginseng cambial meristematic cells (CMCs) were obtained from P. ginseng cambium. This study examined the protective mechanism of wild ginseng CMCs against d-galactosamine (GalN)-induced liver injury. GalN, a well-known hepatotoxicant, causes severe hepatocellular inflammatory damage and clinical features similar to those of human viral hepatitis in experimental animals.

Methods

Hepatotoxicity was induced in rats using GalN (700 mg/kg, i.p.). Wild ginseng CMCs was administered orally once a day for 2 wks, and then 2 h prior to and 6 h after GalN injection.

Results

Wild ginseng CMCs attenuated the increase in serum aminotransferase activity that occurs 24 h after GalN injection. Wild ginseng CMCs also attenuated the GalN-induced increase in serum tumor necrosis factor-α, interleukin-6 level, and hepatic cyclooxygenase-2 protein and mRNA expression. Wild ginseng CMCs augmented the increase in serum interleukin -10 and hepatic heme oxygenase-1 protein and mRNA expression that was induced by GalN, inhibited the increase in the nuclear level of nuclear factor-kappa B, and enhanced the increase in NF-E2-related factor 2.

Conclusion

Our findings suggest that wild ginseng CMCs protects liver against GalN-induced inflammation by suppressing proinflammatory mediators and enhancing production of anti-inflammatory mediators.

Gastroprotective efficacy and safety evaluation of scoparone derivatives on experimentally induced gastric lesions in rodents

This study investigated the gastroprotective efficacy of synthesized scoparone derivatives on experimentally induced gastritis and their toxicological safety. Six scoparone derivatives were synthesized and screened for gastroprotective activities against HCl/ethanol- and indomethacin-induced gastric ulcers in rats. Among these compounds, 5,6,7-trimethoxycoumarin and 6,7,8-trimethoxycoumarin were found to have gastroprotective activity greater than the standard drug rebamipide; 6-methoxy-7,8-methylenedioxycoumarin, 6-methoxy-7,8-(1-methoxy)-methylenedioxycoumarin, 6,7-methylenedioxycoumarin, and 6,7-(1-methoxy)-methylenedioxycoumarin were found to be equipotent or less potent that of rebamipide. Pharmacological studies suggest that the presence of a methoxy group at position C-5 or C-8 of the scoparone's phenyl ring significantly improves gastroprotective activity, whereas the presence of a dioxolane ring at C-6, C-7, or C-8 was found to have decreased activity. In order to assess toxicological safety, two of the potent gastroprotective scoparone derivatives-5,6,7-trimethoxycoumarin and 6,7,8-trimethoxycoumarin-were examined for their acute toxicity in mice as well as their effect on cytochrome P450 (CYP) enzyme activity. These two compounds showed low acute oral toxicity in adult male and female mice, and caused minimal changes to CYP3A4 and CYP2C9 enzyme activity. These results indicate that compared to other scoparone derivatives, 5,6,7-trimethoxycoumarin and 6,7,8-trimethoxycoumarin can improve gastroprotective effects, and they have low toxicity and minimal effects on drug-metabolizing enzymes.

Scoparone interferes with STAT3-induced proliferation of vascular smooth muscle cells

Scoparone, which is a major constituent of Artemisia capillaries, has been identified as an anticoagulant, hypolipidemic, vasorelaxant, anti-oxidant and anti-inflammatory drug, and it is used for the traditional treatment of neonatal jaundice. Therefore, we hypothesized that scoparone could suppress the proliferation of VSMCs by interfering with STAT3 signaling. We found that the proliferation of these cells was significantly attenuated by scoparone in a dose-dependent manner. Scoparone markedly reduced the serum-stimulated accumulation of cells in the S phase and concomitantly increased the proportion of cells in the G0/G1 phase, which was consistent with the reduced expression of cyclin D₁, phosphorylated Rb and survivin in the VSMCs. Cell adhesion markers, such as MCP-1 and ICAM-1, were significantly reduced by scoparone. Interestingly, this compound attenuated the increase in cyclin D promoter activity by inhibiting the activities of both the WT and active forms of STAT3. Similarly, the expression of a cell proliferation marker induced by PDGF was decreased by scoparone with no change in the phosphorylation of JAK2 or Src. On the basis of the immunofluorescence staining results, STAT3 proteins phosphorylated by PDGF were predominantly localized to the nucleus and were markedly reduced in the scoparone-treated cells. In summary, scoparone blocks the accumulation of STAT3 transported from the cytosol to the nucleus, leading to the suppression of VSMC proliferation through G1 phase arrest and the inhibition of Rb phosphorylation. This activity occurs independent of the form of STAT3 and upstream of kinases, such as Jak and Src, which are correlated with abnormal vascular remodeling due to the presence of an excess of growth factors following vascular injury. These data provide convincing evidence that scoparone may be a new preventative agent for the treatment of cardiovascular diseases.

Scoparone attenuates RANKL-induced osteoclastic differentiation through controlling reactive oxygen species production and scavenging

Scoparone, one of the bioactive components of Artemisia capillaris Thunb, has various biological properties including immunosuppressive, hepatoprotective, anti-allergic, anti-inflammatory, and antioxidant effects. This study aims at evaluating the anti-osteoporotic effect of scoparone and its underlying mechanism in vitro. Scoparone demonstrated potent cellular antioxidant capacity. It was also found that scoparone inhibited the receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation and suppressed cathepsin K and tartrate-resistant acid phosphatase (TRAP) expression via c-jun N-terminal kinase (JNK)/extracellular signal-regulated kinase (ERK)/p38-mediated c-Fos-nuclear factor of activated T cells, cytoplasmic 1 (NFATc1) signaling pathway. During osteoclast differentiation, the production of general reactive oxygen species (ROS) and superoxide anions was dose-dependently attenuated by scoparone. In addition, scoparone diminished NADPH (nicotinamide adenine dinucleotide phosphate) oxidase 1 (Nox1) expression and activation via the tumor necrosis factor receptor-associated factor 6 (TRAF6)-cSrc-phosphatidylinositol 3-kinase (PI3k) signaling pathway and prevented the disruption of mitochondrial electron transport chain system. Furthermore, scoparone augmented the expression of superoxide dismutase 1 (SOD1) and catalase (CAT). The overall results indicate that the inhibitory effect of scoparone on RANKL-induced osteoclast differentiation is attributed to the suppressive effect on ROS and superoxide anion production by inhibiting Nox1 expression and activation and protecting the mitochondrial electron transport chain system and the scavenging effect of ROS resulting from elevated SOD1 and CAT expression.

Protective mechanisms of acacetin against D-galactosamine and lipopolysaccharide-induced fulminant hepatic failure in mice

This study examined the hepatoprotective effects of acacetin (1), a flavonoid isolated from Agastache rugosa, against d-galactosamine (GalN) and lipopolysaccharide (LPS)-induced fulminant hepatic failure. Mice were given an intraperitoneal injection of 1 (25, 50, and 100 mg/kg), or the vehicle alone (5% dimethyl sulfoxide-saline), 1 h before GalN (800 mg/kg)/LPS (40 μg/kg) treatment and sacrificed at 6 h after GalN/LPS injection. GalN/LPS markedly increased mortality and serum aminotransferase activity, and these increases were attenuated by 1. GalN/LPS increased serum tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels, while 1 attenuated TNF-α levels and further increased IL-6 levels. GalN/LPS increased protein expression of toll-like receptor 4, phosphorylation of extracellular signal-related kinase, and p38 and c-Jun N-terminal kinase and increased nuclear protein expression of nuclear factor κB; these increases were attenuated by 1. GalN/LPS increased Atg5 and Atg7 protein expressions, and these increases were augmented by 1. GalN/LPS activated autophagic flux as indicated by decreased microtubule-associated protein 1 light chain 3-II and sequestosome1/p62 protein expression. This activation was enhanced by 1. These findings suggest that 1 protects against GalN/LPS-induced liver injury by suppressing TLR4 signaling and enhancing autophagic flux.

Protective effects of lupeol against D-galactosamine and lipopolysaccharide-induced fulminant hepatic failure in mice

This study examined the hepatoprotective effects of lupeol (1, a major active triterpenoid isolated from Adenophora triphylla var. japonica) against d-galactosamine (GalN) and lipopolysaccharide (LPS)-induced fulminant hepatic failure. Mice were orally administered 1 (25, 50, and 100 mg/kg; dissolved in olive oil) 1 h before GalN (800 mg/kg)/LPS (40 μg/kg) treatment. Treatment with GalN/LPS resulted in increased levels of serum alanine aminotransferase, tumor necrosis factor (TNF)-α, and interleukin (IL)-6, as well as increased mortality, all of which were attenuated by treatment with 1. In addition, levels of toll-like receptor (TLR)4, myeloid differentiation primary response gene 88, TIR-domain-containing adapter-inducing interferon-β (TRIF), IL-1 receptor-associated kinase (IRAK)-1, and TNF receptor associated factor 6 protein expression were increased by GalN/LPS. These increases, except TRIF, were attenuated by 1. Interestingly, 1 augmented GalN/LPS-mediated increases in the protein expression of IRAK-M, a negative regulator of TLR signaling. Following GalN/LPS treatment, nuclear translocation of nuclear factor-κB and the levels of TNF-α and IL-6 mRNA expression increased, which were attenuated by 1. Together, the present findings suggest that lupeol (1) ameliorates GalN/LPS-induced liver injury, which may be due to inhibition of IRAK-mediated TLR inflammatory signaling.

Curcumin attenuates D-galactosamine/lipopolysaccharide-induced liver injury and mitochondrial dysfunction in mice

Curcumin, a naturally occurring antioxidant, has various beneficial effects in the treatment of human diseases. However, little information regarding the protection it provides against acute liver injury is available. The present study investigated the protective effects of curcumin against D-galactosamine (D-GalN)/lipopolysaccharide (LPS)-induced acute liver injury in mice. A total of 40 male Kunming mice were randomly assigned to 5 groups: 1) mice administered saline vehicle injection (control), 2) mice administered 200 mg/kg body weight (BW) curcumin by i.p. injection (CUR), 3) mice administered D-GalN/LPS (700 mg and 5 μg/kg BW) via i.p. injection (GL), 4) mice administered 200 mg/kg BW curcumin i.p. 1 h before D-GalN/LPS injection (CUR-GL), and 5) mice administered 200 mg/kg BW curcumin i.p. 1 h after D-GalN/LPS injection (GL-CUR). Twenty h after D-GalN/LPS injection, serum alanine aminotransferase activities were 18.5% and 13.5% lower (P < 0.05) and aspartate aminotransferase (AST) activities were 26.6% and 9.6% lower (P < 0.05) in the CUR-GL and GL-CUR groups, respectively, than in the GL group. The CUR-GL and GL-CUR groups had 64.4% and 15.0% higher (P < 0.05) mitochondrial membrane potentials, respectively, and the CUR-GL group had a 44.7% lower reactive oxygen species concentration than the GL group (P < 0.05). Mitochondrial manganese superoxide dismutase activities were 111% and 77.9% higher (P < 0.05) and the percentages of necrotic cells were 47.0% and 32.4% lower (P < 0.05) in the CUR-GL and GL-CUR groups, respectively, than in the GL group. Liver mRNA levels of sirtuin 1 (Sirt1) were 56.4% lower (P < 0.05) in the CUR-GL group than in the GL group. Moreover, compared with the GL-CUR group, the CUR-GL group had an 18.7% lower serum AST activity, a 31.7% lower mitochondrial malondialdehyde concentration, a 36.0% lower hepatic reactive oxygen species concentration, and a 43.0% higher mitochondrial membrane potential. These results suggested that curcumin protects against D-GalN/LPS-induced liver damage by the enhancing antioxidant defense system, attenuating mitochondrial dysfunction and inhibiting apoptosis. This was especially true for curcumin pretreatment, which highlighted its promise as a preventive treatment for acute liver injury in clinical settings.

BRP, a polysaccharide fraction isolated from Boschniakia rossica, protects against galactosamine and lipopolysaccharide induced hepatic failure in mice

The aim of this study was to investigate the hepatoprotective effect of BRP, a polysaccharide fraction isolated from Boschniakia rossica, against galactosamine and lipopolysaccharide induced fulminant hepatic failure. Mice were injected with a single dose of galactosamine/lipopolysaccharide with or without pretreatment of BRP. Results showed marked reduction of hepatic necrosis, serum marker enzymes and levels of tumor necrosis factor-α and interleukin-6 in BRP pretreated mice when compared with galactosamine/lipopolysaccharide-challenged mice. Mice pretreated with BRP decreased the activation of caspases-3 and caspase-8, and showed a reduced level of DNA fragmentation of liver cells. BRP also reduced hepatic lipid peroxidation, increased potential of hepatic antioxidative defense system, and reduced hepatic nitric oxide level which was elevated by galactosamine/lipopolysaccharide injection. Immunoblot analysis showed down-regulation of inducible nitric oxide synthase and cyclooxygenase-2 proteins of liver tissues in BRP pretreated group when compared with galactosamine/lipopolysaccharide-challenged group. Furthermore, treatment with galactosamine/lipopolysaccharide markedly increased toll-like receptor 4, nuclear level of nuclear factor-κB, and phosphorylation of both extracellular signal-regulated kinase and c-Jun N-terminal kinase in liver tissues. However, these increases were attenuated by pretreatment with BRP. The results suggest that BRP alleviates galactosamine/lipopolysaccharide-induced liver injury by enhancing antioxidative defense system, suppressing inflammatory responses and reducing apoptotic signaling.