Protective effect of oroxylin A against lipopolysaccharide and/or D-galactosamine-induced acute liver injury in mice

Oroxylin A: A Promising Flavonoid for Prevention and Treatment of Chronic Diseases

There have been magnificent advancements in the understanding of molecular mechanisms of chronic diseases over the past several years, but these diseases continue to be a considerable cause of death worldwide. Most of the approved medications available for the prevention and treatment of these diseases target only a single gene/protein/pathway and are known to cause severe side effects and are less effective than they are anticipated. Consequently, the development of finer therapeutics that outshine the existing ones is far-reaching. Natural compounds have enormous applications in curbing several disastrous and fatal diseases. Oroxylin A (OA) is a flavonoid obtained from the plants Oroxylum indicum, Scutellaria baicalensis, and S. lateriflora, which have distinctive pharmacological properties. OA modulates the important signaling pathways, including NF-κB, MAPK, ERK1/2, Wnt/β-catenin, PTEN/PI3K/Akt, and signaling molecules, such as TNF-α, TGF-ꞵ, MMPs, VEGF, interleukins, Bcl-2, caspases, HIF-1α, EMT proteins, Nrf-2, etc., which play a pivotal role in the molecular mechanism of chronic diseases. Overwhelming pieces of evidence expound on the anti-inflammatory, anti-bacterial, anti-viral, and anti-cancer potentials of this flavonoid, which makes it an engrossing compound for research. Numerous preclinical and clinical studies also displayed the promising potential of OA against cancer, cardiovascular diseases, inflammation, neurological disorders, rheumatoid arthritis, osteoarthritis, etc. Therefore, the current review focuses on delineating the role of OA in combating different chronic diseases and highlighting the intrinsic molecular mechanisms of its action.

Oroxylin A ameliorates AKI-to-CKD transition through maintaining PPARα-BNIP3 signaling-mediated mitochondrial homeostasis

Background: Acute kidney injury (AKI) occurs in approximately 7–18% of all hospitalizations, but there are currently no effective drug therapy for preventing AKI or delaying its progression to chronic kidney disease (CKD). Recent studies have shown that Scutellaria baicalensis, a traditional Chinese herb, could attenuate cisplatin-induced AKI, although the mechanism remains elusive. Further, it is unknown whether its major active component, Oroxylin A (OA), can alleviate kidney injury.

Methods: The therapeutic effect of OA was evaluated by using ischemia-reperfusion (IR) and cisplatin mediated-AKI mice and HK-2 cells under hypoxia-reoxygenation (HR) conditions. HE staining, transmission electron microscopy, flow cytometry, immunofluorescence, qPCR, Western blot, PPARα inhibitor, BNIP3 siRNA and ChIP assay were used to explore the role and mechanism of OA in AKI.

Results: OA ameliorated tubular damage and dramatically decreased serum creatinine (Scr) and urea nitrogen (BUN), and the expressions of renal injury markers (Kim-1, Ngal) in AKI mice induced by both IR injury and cisplatin, as well as attenuating AKI-to-CKD transition. In vitro experiments showed that OA alleviated HR-induced mitochondrial homeostasis imbalance in renal tubular epithelial cells. Mechanistically, OA dose-dependently induced the expression of Bcl-2/adenovirus E1B 19-kDa interacting protein (BNIP3), while knockdown of BNIP3 expression reversed the protection of OA against HR-mediated mitochondrial injury. Network pharmacological analysis and experimental validation suggested that OA enhanced BNIP3 expression via upregulating the expression of peroxisome proliferator activated receptor alpha (PPARα), which induced the transcription of BNIP3 via directly binding to its promoter region. Both in vitro and in vivo experiments confirmed that the renoprotective effect of OA was dramatically reduced by GW6471, a PPARα antagonist.

Conclusion: Our findings revealed that OA ameliorates AKI-to-CKD transition by maintaining mitochondrial homeostasis through inducing PPARα-BNIP3 signaling pathway, indicating that OA may serve as a candidate therapeutic strategy for alleviating AKI and CKD.

Dietary phenolic-type Nrf2-activators: implications in the control of toxin-induced hepatic disorders

Numerous studies have exemplified the importance of nuclear factor erythroid 2-related factor 2 (Nrf2) activation in the alleviation of toxin-induced hepatic disorders primarily through eliminating oxidative stress. Whereafter, increasingly more efforts have been contributed to finding Nrf2-activators, especially from dietary polyphenols. The present review summarized the phenolic-type Nrf2-activators published in the past few decades, analyzed their effectiveness based on their structural characteristics and outlined their related mechanisms. It turns out that flavonoids are the largest group of phenolic-type Nrf2-activators, followed by nonflavonoids and phenolic acids. When counting on subgroups, the top three types are flavonols, flavones, and hydroxycinnamic acids, with curcuminoids having the highest effective doses. Moreover, most polyphenols work through the phosphorylation of Nrf2. Besides, mitogen-activated protein kinases (MAPKs) and protein kinase B (Akt) are the frequent targets of these Nrf2-activators, which indirectly mediate the behavior of Nrf2. However, current data are not sufficient to conclude any structure-activity relationship.

Molecular Targets and Mechanisms of Scutellariae radix-Coptidis rhizoma Drug Pair for the Treatment of Ulcerative Colitis Based on Network Pharmacology and Molecular Docking

This study aims to analyze the targets of the effective active ingredients of Scutellariae radix-Coptidis rhizoma drug pair (SCDP) in ulcerative colitis (UC) by network pharmacology and molecular docking and to explore the associated therapeutic mechanism. The effective active ingredients and targets of SCDP were determined from the TCMSP database, and the drug ingredient-target network was constructed using the Cytoscape software. The disease targets related to UC were searched in GeneCards, DisGeNET, OMIM, and DrugBank databases. Then, the drug ingredient and disease targets were intersected to construct a protein-protein interaction network through the STRING database. The Metascape database was used for the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses of the predicted targets of SCDP for UC. The Autodock software was used for molecular docking between the main active ingredient and the core target to evaluate the binding ability. SCDP has 43 effective active ingredients and 134 intersection targets. Core targets included AKT1, TP53, IL-6, VEGFA, CASP3, JUN, TNF, MYC, EGFR, and PTGS2. GO functional enrichment analysis showed that biological process was mainly associated with a cytokine-mediated signaling pathway, response to an inorganic substance, response to a toxic substance, response to lipopolysaccharide, reactive oxygen species metabolic process, positive regulation of cell death, apoptotic signaling pathway, and response to wounding. KEGG enrichment analysis showed main pathway concentrations were related to pathways in cancer, AGE-RAGE signaling pathway in diabetic complications, bladder cancer, IL-17 signaling pathway, apoptosis, p53 signaling pathway, and PI3K-Akt signaling pathway. The drug active ingredient-core target-key pathway network contains 41 nodes and 108 edges, of which quercetin, wogonin, baicalein, acacetin, oroxylin A, and beta-sitosterol are important active ingredients; PTGS2, CASP3, TP53, IL-6, TNF, and AKT1 are important targets; and the pathways involved in UC treatment include pathways in cancer, PI3K-Akt signaling pathway, AGE-RAGE signaling pathway in diabetic, apoptosis, IL-17 signaling pathway and herpes simplex infection. The active ingredient has a good binding capacity to the core target. SCDP key active ingredients are mainly quercetin, wogonin, baicalein, acacetin, oroxylin A, and beta-sitosterol, which function mainly by regulating targets, such as PTGS2, CASP3, TP53, IL-6, TNF, and AKT1, and are associated with multiple signaling pathways as pathways in cancer, PI3K-Akt signaling pathway, apoptosis, IL-17 signaling pathways.

Advances in Pharmacological Actions and Mechanisms of Flavonoids from Traditional Chinese Medicine in Treating Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a common respiratory disease with high morbidity and mortality. The conventional therapies remain palliative and have various undesired effects. Flavonoids from traditional Chinese medicine (TCM) have been proved to exert protective effects on COPD. This review aims to illuminate the poly-pharmacological properties of flavonoids in treating COPD based on laboratory evidences and clinical data and points out possible molecular mechanisms. Animal/laboratory studies and randomised clinical trials about administration of flavonoids from TCM for treating COPD from January 2010 to October 2020 were identified and collected, with the following terms: chronic obstructive pulmonary disease or chronic respiratory disease or inflammatory lung disease, and flavonoid or nature product or traditional Chinese medicine. Pharmacokinetic studies and external application treatment were excluded. A total of 15 flavonoid compounds were listed. Flavonoids could inhibit inflammation, oxidative stress, and cellular senescence, restore corticosteroid sensitivity, improve pulmonary histology, and boost pulmonary function through regulating multiple targets and signaling pathways, which manifest that flavonoids are a group of promising natural products for COPD. Nevertheless, most studies remain in the research phase of animal testing, and further clinical applications should be carried out.

Oroxylin A attenuates osteoarthritis progression by dual inhibition of cell inflammation and hypertrophy

The imbalance between the anabolism and catabolism of the extracellular matrix (ECM) is of great importance to osteoarthritis (OA) development. Aberrant inflammatory responses and hypertrophic changes of chondrocytes are the main contributors to these metabolic disorders. In the present study, we found that Oroxylin A (ORA), a flavonoid compound derived from Oroxylum indicum, maintained ECM hemostasis of chondrocytes by Interleukin-1β (IL-1β) stimulation. Besides, it was demonstrated that IL-1β induced over-production of inflammatory mediators was attenuated by ORA treatment. Moreover, ORA could rescue IL-1β mediated hypertrophic alterations of chondrocytes. Mechanistically, ORA's protective effects were found to be associated with both NF-κB and Wnt/β-catenin signaling inhibition. Meanwhile, molecular docking analysis revealed that ORA could strongly bind to the inhibitor kappa B kinaseβ (IKKβ) and dishevelled, Dsh Homolog 2 (Dvl2), the upstream molecules of the NF-κB axis and β-catenin axis, respectively. In addition, ORA driven chondroprotective effects were also affirmed in a surgically induced OA mouse model. Taken together, the current study suggested that ORA might be a promising therapeutic option for the treatment of OA.

The main bioactive compounds of Scutellaria baicalensis Georgi. for alleviation of inflammatory cytokines: A comprehensive review

Scutellaria baicalensis Georgi., a plant used in traditional Chinese medicine, has multiple biological activities, including anti-inflammatory, antiviral, antitumor, antioxidant, and antibacterial effects, and can be used to treat respiratory tract infections, pneumonia, colitis, hepatitis, and allergic diseases. The main active substances of S. baicalensis, baicalein, baicalin, wogonin, wogonoside, and oroxylin A, can act directly on immune cells such as lymphocytes, macrophages, mast cells, dendritic cells, monocytes, and neutrophils, and inhibit the production of the inflammatory cytokines IL-1β, IL-6, IL-8, and TNF-α, and other inflammatory mediators such as nitric oxide, prostaglandins, leukotrienes, and reactive oxygen species. The molecular mechanisms underlying the immunomodulatory and anti-inflammatory effects of the active compounds of S. baicalensis include downregulation of toll-like receptors, activation of the Nrf2 and PPAR signaling pathways, and inhibition of the nuclear thioredoxin system and inflammation-associated pathways such as those of MAPK, Akt, NFκB, and JAK-STAT. Given that in addition to the downregulation of cytokine production, the active constituents of S. baicalensis also have antiviral and antibacterial effects, they may be more promising candidate therapeutics for the prevention of infection-related cytokine storms than are drugs having only antimicrobial or anti-inflammatory activities.

Oroxylin A alleviates immunoparalysis of CLP mice by degrading CHOP through interacting with FBXO15

Clinical reports have found that with the improvement of treatment, most septic patients are able to survive the severe systemic inflammatory response and to enter the immunoparalysis stage. Considering that immunoparalysis leads to numerous deaths of clinical sepsis patients, alleviation of the occurrence and development of immunoparalysis has become a top priority in the treatment of sepsis. In our study, we investigate the effects of oroxylin A on sepsis in cecal ligation and puncture (CLP) mice. We find that the 60 h + 84 h (30 mg/kg) injection scheme of oroxylin A induce the production of pro-inflammatory factors, and further significantly improves the survival of CLP mice during the middle or late stages of sepsis. Mechanistically, C/EBP-homologous protein (CHOP) is upregulated and plays anti-inflammatory roles to facilitate the development of immunoparalysis in CLP mice. Oroxylin A induces the transcription of E3 ligase F-box only protein 15 gene (fbxo15), and activated FBXO15 protein binds to CHOP and further mediates the degradation of CHOP through the proteasome pathway, which eventually relieves the immunoparalysis of CLP mice. Taken together, these findings suggest oroxylin A relieves the immunoparalysis of CLP mice by degrading CHOP through interacting with FBXO15.

Pterostilbene Protects Against Lipopolysaccharide/D-Galactosamine-Induced Acute Liver Failure by Upregulating the Nrf2 Pathway and Inhibiting NF-κB, MAPK, and NLRP3 Inflammasome Activation

The purpose of this study was to evaluate the protective effect of pterostilbene (Psb) against lipopolysaccharide and D-galactosamine (L/D)-induced acute liver failure (ALF) in mice and its potential mechanisms. Histology of liver was detected by H&E staining. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels in serum and malondialdehyde (MDA), myeloperoxidase (MPO), glutathione (GSH), and superoxide dismutase (SOD) contents in liver were examined using detection kits. The levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) secretion were detected by ELISA. Meanwhile, MAPK, NF-κB, NLRP3 inflammasome, and Nrf2 were assessed by western blotting. Our findings showed that pretreatment with Psb protected against L/D-induced ALF by lowering the lethality, improving liver histology, reducing ALT, AST, IL-6, IL-1β, TNF-α, MDA, and MPO levels, and boosting liver GSH content and SOD activity. Moreover, Psb pretreatment effectively suppressed inflammation by decreasing NLRP3 inflammasome, MAPK, and NF-κB pathway activations. Moreover, Psb pretreatment efficiently enhanced the expression of several antioxidant enzymes, mainly depending on Nrf2 activation. This was the first study to demonstrate that Psb protects against L/D-induced ALF by inactivating MAPK, NF-κb, and NLRP3 inflammasome and upregulating the Nrf2 signaling pathway, indicating a potential therapeutic application for ALF treatment.

Hepatoprotective effect of chiisanoside from Acanthopanax sessiliflorus against LPS/D-GalN-induced acute liver injury by inhibiting NF-κB and activating Nrf2/HO-1 signaling pathways

BACKGROUND

In China, Acanthopanax sessiliflorus is a delicious wild vegetable. It is also used to treat inflammation and pain. Chiisanoside (CSS) is the main constituent of the leaf of A. sessiliflorus. Combined use of lipopolysaccharide and d-galactosamine (LPS/D-GalN) can induce acute liver failure in human beings, and there are no reports on the protective effect of CSS against LPS/D-GalN-induced acute liver injury in mice.

RESULTS

Chiisanoside pretreatment evidently reduced the activities of alanine transaminase (ALT) and aspartate transaminase (AST) in the changes induced by LPS/D-GalN, and these histopathological changes induced by LPS/GalN were significantly weakened. Catalase (CAT), glutathione (GSH), and superoxide dismutase (SOD) activities increased, and malondialdehyde (MDA) activity decreased after CSS treatment compared with LPS/D-GalN treatment. Pretreatment with CSS also inhibited the expression levels of inflammatory factors. The administration of CSS prevented the phosphorylated expression of inhibitor kappa B (IκB) kinase, and led to a significant increase in heme oxygenase-1 (HO-1) expression and nuclear factor erythroid 2-related factor2 (Nrf2) nuclear translocation.

CONCLUSION

The protective effects of CSS are attributed to its antioxidative effect and inflammatory suppression in Nuclear factor kappa beta (NF-κB) and Nrf2/HO-1 signaling pathways. Chiisanoside might therefore be a potential ingredient for drug and food development against acute liver injury in the future. © 2018 Society of Chemical Industry.

Saikosaponin a ameliorates lipopolysaccharide and d‑galactosamine-induced liver injury via activating LXRα

Saikosaponin a (SSa), one of the major active components of Bupleurum falcatum, has antioxidant and anti-inflammatory pharmacological properties. However, the effects of SSa on liver injury have not been reported. In the present study, we evaluated the protective effects and mechanisms of SSa on lipopolysaccharide (LPS)/d‑galactosamine (D-GalN)-induced liver injury. The mice were pretreated with SSa 1 h before LPS/D-GalN treatment. The liver MPO, MDA, and the serum AST and ALT levels were tested by specific determination kits. The pro-inflammatory cytokines TNF-α and IL-1β were tested by ELISA kits. The expression of NF-κB signaling pathway and LXRα were tested by western blot analysis. The results showed that SSa significantly reduced the levels of liver MPO, MDA, and serum AST, ALT levels induced by LPS/D-GalN. SSa also dose-dependently inhibited LPS/D-GalN-induced pro-inflammatory cytokines TNF-α and IL-1β production. Furthermore, we found that SSa inhibited NF-κB signaling pathway activation induced by LPS/D-GalN. In addition, SSa dose-dependently increased the expression of LXRα. In conclusion, the results demonstrated that SSa had protective effect on liver injury and the anti-inflammatory mechanisms of SSa on LPS/D-GalN-induced liver injury may be due to its ability to increase LXRα expression. SSa might be a potential treatment for liver injury.

Corilagin alleviates acetaminophen-induced hepatotoxicity via enhancing the AMPK/GSK3β-Nrf2 signaling pathway

Background

Acetaminophen (APAP) overdose-induced acute liver failure (ALF) is mainly resulted from uncontrolled oxidative stress. Nuclear factor-erythroid 2-related factor 2 (Nrf2), a key antioxidant transcription factor, is essential for alleviating APAP-induced hepatotoxicity. Corilagin (Cori) is a natural polyphenol compound that possesses effective antioxidant activity; however, the protective effect of Cori on APAP-induced hepatotoxicity is still unknown. The current study aimed to explore whether Cori could mitigate hepatotoxicity caused by APAP and the underlying molecular mechanisms of action.

Methods

Cell counting kit-8 (CCK-8) assays, Western blotting analysis, dual-luciferase reporter assays, a mouse model, CRISPR/Cas9 knockout technology, and hematoxylin-eosin (H & E) staining were employed to explore the mechanisms by which Cori exerts a protective effect on hepatotoxicity in HepG2 cells and in a mouse model.

Results

Our findings suggested that Cori efficiently decreased APAP-triggered the generation of reactive oxygen species (ROS) and cell death in HepG2 cells. Additionally, Cori significantly induced the expression of several antioxidant enzymes, and this induced expression was closely linked to the upregulation of Nrf2, inhibition of Keap1 protein expression, and promotion of antioxidant response element (ARE) activity in HepG2 cells. Moreover, Cori clearly induced the phosphorylation of AMP-activated protein kinase (AMPK), glycogen synthase kinase-3β (GSK3β), liver kinase B1 (LKB1) and acetyl-CoA carboxylase (ACC). Furthermore, Cori-mediated GSK3β inactivation, Nrf2 upregulation and cytoprotection were abolished by an AMPK inhibitor (Compound C) in HepG2 cells. Lastly, we found that Cori inhibited APAP-induced hepatotoxicity and mediated the expression of many antioxidant enzymes; these results were reversed in Nrf2 ^−/− HepG2 cells. In vivo, Cori significantly protected against APAP-induced ALF by reducing mortality and alanine transaminase (ALT) and aspartate aminotransferase (AST) levels, attenuating histopathological liver changes, inhibiting myeloperoxidase (MPO) and malondialdehyde (MDA) levels, and increasing the superoxide dismutase (SOD) content and GSH-to-GSSG ratio as well as suppressing c-jun N-terminal kinase (JNK) phosphorylation. However, Cori-induced reductions in mortality, AST and ALT levels, and histopathological liver changes induced by APAP were clearly abrogated in Nrf2-deficienct mice.

Conclusions

These findings principally indicated that Cori effectively protects against APAP-induced ALF via the upregulation of the AMPK/GSK3β-Nrf2 signaling pathway.

Amygdalin attenuates acute liver injury induced by D-galactosamine and lipopolysaccharide by regulating the NLRP3, NF-κB and Nrf2/NQO1 signalling pathways

Acute liver injury (ALI) is a life-threatening syndrome accompanied by overwhelming inflammation. Amygdalin (AGD) has been reported to possess various biological activities, particularly anti-inflammatory activity. The current study was designed to assess the protective effects and underlying mechanisms of AGD against ALI induced by d-galactosamine (GalN) and lipopolysaccharide (LPS) in mice. The results indicated that AGD treatment effectively reduced the lethality, ameliorated the histopathological liver changes, reduced the malondialdehyde (MDA) and myeloperoxidase (MPO) levels, and decreased the alanine transaminase (ALT) and aspartate aminotransferase (AST) levels resulting from LPS/GalN challenge. Moreover, AGD significantly inhibited LPS/GalN-induced inflammatory responses in mice with ALI by reducing not only the secretion of tumour necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 but also the protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Additionally, our results demonstrated that the inhibitory effect of AGD was due to the suppressed activation of nuclear factor-kappa B (NF-κB) and nucleotide-binding domain (NOD-)like receptor protein 3 (NLRP3) inflammasome activity. Furthermore, AGD treatment substantially increased nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation and enhanced NAD (P) H: quinoneoxidoreductase 1 protein expression, which was reversed by a Nrf2 inhibitor, in HepG2 cells. In summary, our investigations suggested that the ability of AGD to ameliorate LPS/GalN-induced ALI may involve the inhibition of the NLRP3 inflammasome and NF-κB signalling pathways and the upregulation of the Nrf2/NQO1 signalling pathway.

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

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

Oroxylin A inhibits ethanol-induced hepatocyte senescence via YAP pathway

OBJECTIVES

Oroxylin A, a natural flavonoid isolated from Scutellaria baicalensis, has been reported to have anti-hepatic injury effects. However, the effects of oroxylin A on alcoholic liver disease (ALD) remains unclear. The aim of this study was to elucidate the effects of oroxylin A on ALD and the potential mechanisms.

MATERIALS AND METHODS

Male ICR mice and human hepatocyte cell line LO₂ were used. Yes-associated protein (YAP) overexpression and knockdown were achieved using plasmid and siRNA technique. Cellular senescence was assessed by analyses of the senescence-associated β-galactosidase (SA-β-gal), senescence marker p16, p21, Hmga1, cell cycle and telomerase activity.

RESULTS

Oroxylin A alleviated ethanol-induced hepatocyte damage by suppressing activities of supernatant marker enzymes. We found that oroxylin A inhibited ethanol-induced hepatocyte senescence by decreasing the number of SA-β-gal-positive LO₂ cells and reducing the expression of senescence markers p16, p21 and Hmga1 in vitro. Moreover, oroxylin A affected the cell cycle and telomerase activity. Of importance, we revealed that YAP pharmacological inhibitor verteporfin or YAP siRNA eliminated the effect of oroxylin A on ethanol-induced hepatocyte senescence in vitro, and this was further supported by the evidence in vivo experiments.

CONCLUSION

Therefore, these aggregated data suggested that oroxylin A relieved alcoholic liver injury possibly by inhibiting the senescence of hepatocyte, which was dependent on its activation of YAP in hepatocytes.

Oroxylin A suppresses influenza A virus replication correlating with neuraminidase inhibition and induction of IFNs

Because it is highly contagious, the influenza A virus (IAV) has the potential to cause pandemics in humans. The emergence of drug-resistant strains requires the development of new chemical therapeutics. Oroxylin A (OA) is a flavonoid which has been shown to have antioxidant and antitumor effects. However, intensive studies in which OA fights against different influenza virus strains and the underlying antiviral mechanisms have not been reported. In our study, the antiviral activities in cells and in mice, the preliminary mechanisms of OA were investigated. Our data show that it can inhibit A/FM/1/47 (H1N1), A/Beijing/32/92 (H3N2) and oseltamivir-resistant A/FM/1/47-H275Y (H1N1-H275Y) viruses in MDCK cells in a dose-dependent manner with inhibitory rates of 70.9%, 59.5% and 23.2%, respectively, at 50μM doses. Orally administered OA effectively protected mice from H1N1 virus-induced death, body weight loss and lung injury, with a survival rate of 60.0% at 100mg/kg/d dose. In addition, the H1N1 M1 gene transcription and protein synthesis were suppressed by 43.7% and 33.2%, respectively, in the late biosynthesis stage. This resulted in inhibition of viral replication. Furthermore, we found that OA has a neuraminidase (NA) inhibitory effect with IC₅₀ values for H1N1-H275Y and A/Anhui/1/2013-R294K (H7N9-R294K) of 241.4μM and 203.6μM, respectively. Interferons (IFNs) produced by the virally infected cells play important roles in antiviral defense, therefore, IFN levels in the blood were also tested in mice. We found that IFN-β and IFN-γ in the OA 100mg/kg/d group were markedly increased by 24.5pg/mL and 859.9pg/mL, respectively, compared with those in the model group. This indicated that OA could induce the secretion of IFNs. The potent inhibition of virus replication and NA inhibitory activity, as well as the promotion of IFN production suggest that OA could be a drug candidate to fight against IAVs including oseltamivir-resistant strains.

Role of Human Wharton's Jelly Derived Mesenchymal Stem Cells (WJ-MSCs) for Rescue of d-Galactosamine Induced Acute Liver Injury in Mice

BACKGROUND/AIM

Mesenchymal stem cells (MSCs) are multipotent precursor cells having self-renewal ability making them a candidate for use in regenerative medicine. Acute liver injury results in sudden loss of hepatic function leading to organ failure. Liver transplantation is often required to salvage patients with acute liver failure. Due to shortage of organs, identification of alternate method is the need of the hour. In view of this, an attempt has been made to check the regenerative ability of WJ-MSCs (wharton's jelly derived MSC) in mice models for acute liver injury.

METHODS

Swiss albino mice weighing 25 ± 5 g were used in this study. The control mice (Group I), was given saline. Group II mice received d-Galactosamine (d-GalN-800 mg/kg; i.p). Group III mice similar with Group II, received WJ-MSCs (5 × 105 cells/0.5 ml DMEM) through tail vein, 24 h after d-GalN administration and Group IV mice received MSC alone.

RESULTS

Parameters, indicative of hepatotoxicity and oxidative stress were analyzed. A two-fold elevation in the marker enzymes of liver toxicity such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (SAP), and total serum bilirubin (TBIL) confirms hepatocellular injury, while a greater than four-fold increase in malondialdehyde (MDA) formation, along with around 40% fall in superoxide-dis-mutase (SOD) activity was indicative of oxidative stress and loss of hepatocellular membrane integrity induced by d-GalN. The above biochemical and pathological changes were significantly restored in mice that received WJ-MSCs indicating hepatoprotective and probable regenerative property.

CONCLUSION

The present study showed that WJ-MSC treatment is able to rescue/ameliorate the hepatotoxicity induced by d-GalN in mice.

Asiatic Acid Exhibits Anti-inflammatory and Antioxidant Activities against Lipopolysaccharide and d-Galactosamine-Induced Fulminant Hepatic Failure

Inflammation and oxidative stress are essential for the pathogenesis of fulminant hepatic failure (FHF). Asiatic acid (AA), which is a pentacyclic triterpene that widely occurs in various vegetables and fruits, has been reported to possess antioxidant and anti-inflammatory properties. In this study, we investigated the protective effects of AA against lipopolysaccharide (LPS) and d-galactosamine (GalN)-induced FHF and the underlying molecular mechanisms. Our findings suggested that AA treatment effectively protected against LPS/d-GalN-induced FHF by lessening the lethality; decreasing the alanine transaminase and aspartate aminotransferase levels, interleukin (IL)-1β, IL-6, and tumor necrosis factor-α production, malondialdehyde formation, myeloperoxidase level and reactive oxygen species generation (i.e., H₂O₂, NO, and O2−), and increasing the glutathione and superoxide dismutase contents. Moreover, AA treatment significantly inhibited mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) signaling pathway activation via the partial induction of programmed cell death 4 (PDCD4) protein expressions, which are involved in inflammatory responses. Furthermore, AA treatment dramatically induced the expression of the glutamate-cysteine ligase modifier subunit, the glutamate-cysteine ligase catalytic subunit, heme oxygenase-1, and NAD (P) H: quinoneoxidoreductase 1 (NQO1), which are largely dependent on activation of the nuclear factor-erythroid 2-related factor 2 (Nrf2) through the induction of AMP-activated protein kinase (AMPK) and glycogen synthase kinase-3β (GSK3β) phosphorylation. Accordingly, AA exhibited protective roles against LPS/d-GalN-induced FHF by inhibiting oxidative stress and inflammation. The underlying mechanism may be associated with the inhibition of MAPK and NF-κB activation via the partial induction of PDCD4 and upregulation of Nrf2 in an AMPK/GSK3β pathway activation-dependent manner.

Simultaneous determination of wogonin, oroxylin a, schisandrin, paeoniflorin and emodin in rat serum by HPLC-MS/MS and application to pharmacokinetic studies

Wogonin and oroxylin A in Scutellariae Radix, schisandrin in Chinensis Fructus, paeoniflorin in Moutan Cortex and emodin in Polygoni Cuspidate Rhizome et Radix are anti-inflammatory active compounds. A method for simultaneous determination of the five compounds in rat was developed and validated using high-performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS). The separation was performed on a Symmetry C₁₈ column (4.6 × 50 mm, 3.5 μm) with acetonitrile and 0.1% formic acid aqueous solution as the mobile phases. The detection was performed using multiple-reaction monitoring with electrospray ionization source in positive-negative ion mode. The calibration curves showed good linearity (r ≥ 0.9955). The lower limit of quantification (LLOQ) was 5 ng/mL for wogonin and schisandrin, 10 ng/mL for oroxylin A and emodin, and 15 ng/mL for paeoniflorin, respectively. The relative standard deviations of intraday and interday precisions were <11.49 and 14.28%, respectively. The extraction recoveries and matrix effects were acceptable. The analytes were stable under the experiment conditions. The validated method has been successfully applied to pharmacokinetic studies of the five compounds in rats after oral administration of Hu-gan-kan-kang-yuan capsule. This paper would be a valuable reference for pharmacokinetic studies of Chinese medicine preparations containing the five compounds.

Oroxylin A Inhibits Allergic Airway Inflammation in Ovalbumin (OVA)-Induced Asthma Murine Model

Oroxylin A, a natural flavonoid isolated from the medicinal herb Scutellaria baicalensis Georgi, has been reported to have anti-inflammatory property. In this study, we aimed to investigate the protective effects and mechanism of oroxylin A on allergic inflammation in OVA-induced asthma murine model. BABL/c mice were sensitized and airway-challenged with OVA to induce asthma. Oroxylin A (15, 30, and 60 mg/kg) was administered by oral gavage 1 h before the OVA treatment on day 21 to 23. The results showed that oroxylin A attenuated OVA-induced lung histopathologic changes, airway hyperresponsiveness, and the number of inflammatory cells. Oroxylin A also inhibited the levels of IL-4, IL-5, IL-13, and OVA-specific IgE in BALF. Furthermore, oroxylin A significantly inhibited OVA-induced NF-κB activation. In conclusion, these results suggested that oroxylin A inhibited airway inflammation in OVA-induced asthma murine model by inhibiting NF-κB activation. These results suggested that oroxylin A was a potential therapeutic drug for treating allergic asthma.

Naturally Occurring Nrf2 Activators: Potential in Treatment of Liver Injury

Oxidative stress plays a major role in acute and chronic liver injury. In hepatocytes, oxidative stress frequently triggers antioxidant response by activating nuclear erythroid 2-related factor 2 (Nrf2), a transcription factor, which upregulates various cytoprotective genes. Thus, Nrf2 is considered a potential therapeutic target to halt liver injury. Several studies indicate that activation of Nrf2 signaling pathway ameliorates liver injury. The hepatoprotective potential of naturally occurring compounds has been investigated in various models of liver injuries. In this review, we comprehensively appraise various phytochemicals that have been assessed for their potential to halt acute and chronic liver injury by enhancing the activation of Nrf2 and have the potential for use in humans.

Application of Bioactive Compounds from Scutellaria in Neurologic Disorders

Inflammation of the brain is one of the most highly researched yet mysterious areas in modern day neurology. The process of inflammation is a normal mechanism of wound healing that can result from acute injuries such as traumas or can be caused by genetic/environmental factors. After the initial insult, the immune system defenses, specifically microglial cells, are activated in order to combat the infection or injury. However, prolonged or chronic inflammation is often deleterious due mainly to accumulation of free reactive oxygen species (ROS) and other pro-inflammatory cytokines in the brain FADDIN EN.CITE. Plant-derived natural compounds have the potential to ameliorate the causes and symptoms of neuroinflammation, due to their various anti-oxidant and anti-inflammatory activities, without completely muting the immune defenses. Scutellaria is a perennial plant in the mint family that has been used to treat diseases in Asia and Eastern Europe throughout history. This chapter reviews the active components of various Scutellaria species and their mechanisms of action to prevent chronic neurologic disorders involving neuroinflammation and neurodegeneration.