Modulation of PI3K-LXRα-dependent lipogenesis mediated by oxidative/nitrosative stress contributes to inhibition of HCV replication by quercetin

Pistacia vera L. as natural source against antimicrobial and antiviral resistance

Increased global research is focused on the development of novel therapeutics to combat antimicrobial and antiviral resistance. Pistachio nuts represent a good source of protein, fiber, monounsaturated fatty acids, minerals, vitamins, and phytochemicals (carotenoids, phenolic acids, flavonoids and anthocyanins). The phytochemicals found in pistachios are structurally diverse compounds with antimicrobial and antiviral potential, demonstrated as individual compounds, extracts and complexed into nanoparticles. Synergistic effects have also been reported in combination with existing drugs. Here we report an overview of the antimicrobial and antiviral potential of pistachio nuts: studies show that Gram-positive bacterial strains, such as Staphylococcus aureus, are the most susceptible amongst bacteria, whereas antiviral effect has been reported against herpes simplex virus 1 (HSV-1). Amongst the known pistachio compounds, zeaxanthin has been shown to affect both HSV-1 attachment penetration of human cells and viral DNA synthesis. These data suggest that pistachio extracts and derivatives could be used for the topical treatment of S. aureus skin infections and ocular herpes infections.

Medicinal plant molecules against hepatitis C virus: Current status and future prospect

Hepatitis C virus (HCV), a global malady, causes acute and chronic hepatitis leading to permanent liver damage, hepatocellular carcinoma, and death. Modern anti-HCV therapies are efficient, but mostly inaccessible for residents of underdeveloped regions. To innovate more effective treatments at affordable cost, medicinal plant-based products need to be explored. The aim of this article is to review plant constituents in the light of putative anti-HCV mechanisms of action, and discuss existing problems, challenges, and future directions for their potential application in therapeutic settings. One hundred sixty literatures were collected by using appropriate search strings via scientific search engines: Google Scholar, PubMed, ScienceDirect, and Scopus. Bibliography was prepared using Mendeley desktop software. We found a substantial number of plants that were reported to inhibit different stages of HCV life cycle. Traditional medicinal plants such as Phyllanthus amarus Schumach. and Thonn., Eclipta alba (L.) Hassk., and Acacia nilotica (L.) Delile exhibited strong anti-HCV activities. Again, several phytochemicals such as epigallocatechin-3-gallate, honokilol, punicalagin, and quercetin have shown broad-spectrum anti-HCV effect. We have presented promising phytochemicals like silymarin, curcumin, glycyrrhizin, and camptothecin for nanoparticle-based hepatocyte-targeted drug delivery. Nevertheless, only a few animal studies have been performed to validate the anti-HCV effect of these plant products. Again, insufficient clinical evaluation of the safety and effectiveness of herbal medications remain a problem. Selected plants products could be developed as novel therapeutics for HCV patients only after scrupulous evaluation of their safety and efficacy in a clinical set-up.

Quercetin as a Dietary Supplementary Flavonoid Alleviates the Oxidative Stress Induced by Lead Toxicity in Male Wistar Rats

Quercetin is a naturally existing plant pigment belonging to the flavonoid group; it is contained in a wide range of vegetables and fruits. The accumulated evidence points to the potential uses of quercetin in protection of some disease conditions. Lead is one of the highly toxicant heavy metals that are widely spread in the environment and implicated in a wide spectrum of industries. No previous study has been reported to evaluate the effect of quercetin on lead toxicity. Therefore, the present study was conducted to elucidate some aspects of quercetin bioactivities in regard to its ability to combat the oxidative stress induced by lead toxicity. For this purpose, a total of sixty male Wistar rats were randomly and equally divided into three groups of 20 animals each; untreated control animals (group 1), lead-exposed animals (group 2; exposed to lead daily by oral gavage at the dose of 80 mg/Kg b.w.), and group 3 of animals, which were exposed to lead and daily received quercetin (10 h gap time between lead exposure and the receiving of quercetin) by oral gavage at the dose of 350 mg/Kg b.w. The experiment period was 8 weeks. All the assayed hematological and biochemical parameters of animals exposed to lead were significantly altered compared with the untreated control levels. Animals exposed to lead (group 2) exhibited significant decrements of the erythrocytic and total leucocytic counts, hemoglobin concentration, packed cell volume percent, total proteins, albumin and globulin. These animals also disclosed significantly decreased levels of antioxidant markers including total thiols, catalase and glutathione. On the other hand, these animals demonstrated significant increments in the levels of bilirubin, urea, creatinine, BUN, serum enzymes, H₂O₂ and MDA. Animals exposed to lead and given quercetin (group 3) exhibited improvement of these parameters, which were brought back at varying degrees toward the untreated control levels. Basing on the improvements of the assayed hematological and biochemical parameters, it was concluded that quercetin as a dietary supplement can act efficiently as an antioxidant to counteract the oxidative stress induced by lead toxicity and to maintain the oxidant antioxidant balance.

Targeting BRD4 and PI3K signaling pathways for the treatment of medulloblastoma

Medulloblastoma (MB) is a malignant pediatric brain tumor which shows upregulation of MYC and sonic hedgehog (SHH) signaling. SHH inhibitors face acquired resistance, which is a major cause of relapse. Further, direct MYC oncogene inhibition is challenging, inhibition of MYC upstream insulin-like growth factor/ phosphatidylinositol-4,5-bisphosphate 3-kinase (IGF/PI3K) is a promising alternative. While PI3K inhibition activates resistance mechanisms, simultaneous inhibition of bromodomain-containing protein 4 (BRD4) and PI3K can overcome resistance. We synthesized a new molecule 8-(2,3-dihydrobenzo[b] [1, 4] dioxin-6-yl)-2-morpholino-4H-chromen-4-one (MDP5) that targets both BRD4 and PI3K pathways. We used X-ray crystal structures and a molecular modeling approach to confirm the interactions between MDP5 with bromo domains (BDs) from both BRD2 and BRD4, and molecular modeling for PI3K binding. MDP5 was shown to inhibit target pathways and MB cell growth in vitro and in vivo. MDP5 showed higher potency in DAOY cells (IC50 5.5 μM) compared to SF2523 (IC50 12.6 μM), and its IC50 values in HD-MB03 cells were like SF2523. Treatment of MB cells with MDP5 significantly decreased colony formation, increased apoptosis, and halted cell cycle progression. Further, MDP5 was well tolerated in NSG mice bearing either xenograft or orthotopic MB tumors at the dose of 20 mg/kg, and significantly reduced tumor growth and prolonged animal survival.

The long and stumble way to find potential active compounds from plants for defeating hepatitis B and C: review

Hepatitis is a liver illness caused by virus such as hepatitis A virus, hepatitis B virus and hepatitis C virus. Hepatitis B and C are considerably more usual and induce more cirrhosis and dead worldwide than hepatitis A. Although drugs that are currently often used in the medication of hepatitis B and C, the finding of recent drug from various resources including herbal has been intensively developed. Therefore, the purpose of this review is to consider the possibility of plant’s compounds as anti-HBV and anti-HCV. From the results of a review of several articles, several plant’s compound have shown effectiveness againts HBV and HCV by in silico, in vitro and in vivo studies. In conclusion, several plant’s active compounds are possibility to be developed as anti-hepatitis B and C.

Quercetin, a flavonoid, combats rotavirus infection by deactivating rotavirus-induced pro-survival NF-κB pathway

Rotavirus (RV) is the leading cause of acute gastroenteritis and watery diarrhea in children under 5 years accounting for high morbidity and mortality in countries with poor socioeconomic status. Although vaccination against RV has been implemented in more than 100 countries, the efficacy of vaccine has been challenged in low-income settings. The lack of any FDA-approved drug against RV is an additional concern regarding the treatment associated with rotavirus-induced infantile death. With the purpose for the discovery of anti-RV therapeutics, we assessed anti-rotaviral potential of quercetin, a well-characterized antioxidant flavonoid. In vitro study revealed that quercetin treatment resulted in diminished production of RV-SA11 (simian strain) viral particles in a concentration-dependent manner as estimated by the plaque assay. Consistent with this result, Western blot analysis also revealed reduced synthesis of viral protein in quercetin-treated RV-SA11-infected MA104 cells compared to vehicle (DMSO) treated controls. Not surprisingly, infection of other RV strains A5-13 (bovine strain) and Wa (Human strain) was also found to be abridged in the presence of quercetin compared to DMSO. The IC₅₀ of quercetin against three RV strains ranges between 2.79 and 4.36 Mm, and S.I. index is greater than 45. Concurrent to the in vitro results, in vivo study in mice model also demonstrated reduced expression of viral proteins and viral titer in the small intestine of quercetin-treated infected mice compared to vehicle-treated infected mice. Furthermore, the result suggested anti-rotaviral activity of quercetin to be interferon-independent. Mechanistic study revealed that the antiviral action of quercetin is co-related with the inhibition of RV-induced early activation of NF-κB pathway. Overall, this study delineates the strong anti-RV potential of quercetin and also proposes it as future therapeutics against rotaviral diarrhea.

Integrative Metabolome and Transcriptome Analysis of Flavonoid Biosynthesis Genes in Broussonetia papyrifera Leaves From the Perspective of Sex Differentiation

Flavonoids are important secondary metabolites involved in plant development and environmental responses. Sex differences in flavonoids are common in plants. Broussonetia papyrifera is a dioecious plant that is rich in flavonoids. However, few studies have been done on its molecular mechanism, especially sex differences. In the present study, we performed an integrated transcriptomics and metabolomics analysis of the sex differences in the accumulation of flavonoids in B. papyrifera leaves at different developmental stages. In general, flavonoids accumulated gradually with developmental time, and the content in female plants was higher than that in male plants. The composition of flavonoids in female and male plants was similar, and 16 kinds of flavonoids accumulated after flowering. Correspondingly, a significant enrichment of differentially expressed genes and metabolites was observed in the flavonoid biosynthesis pathway. WGCNA and qRT-PCR analyses identified several key genes regulating the accumulation of flavonoids, such as those encoding CHS, CHI and DFR. In addition, 8 TFs were found to regulate flavonoid biosynthesis by promoting the expression of multiple structural genes. These findings provide insight into flavonoid biosynthesis in B. papyrifera associated molecular regulation.

Focus on the high therapeutic potentials of quercetin and its derivatives

BACKGROUND

Polyphenols and particularly flavonoids are of constant interest to the scientific community. Flavonoids are investigated for their biological and pharmacological purposes, notably as antioxidant, anticancer, antiviral and for their anti-inflammatory activities. Certainly, one of the best-known flavonols recognized for its therapeutic and preventive properties, is quercetin. Despite its biological interest, quercetin suffer from some drawbacks, mainly related to its bioavailability. Hence, its synthetic or biosynthetic derivatives have been the subject of intensive research. The health-promoting biological activities of flavonols and derivatives mainly arise from their capacity to disrupt the host-pathogen interactions and/or to regulate host cellular functions including oxidative processes and immunological responses. In the age of coronavirus pandemic, the anti-inflammatory and antiviral potential of flavonols should be put forward to explore these substances for decreasing the viral load and inflammatory storm caused by the infection.

PURPOSE OF STUDY

The present review will decipher and discuss the antioxidant, anti-inflammatory and antiviral capacities of major flavonol with a focus on the molecular basis and structure-activity relationships.

STUDY DESIGN

Current study used a combination of quercetin derivatives, pathway, antioxidant, anti-inflammatory, antiviral activities as keywords to retrieve the literature. This study critically reviewed the current literature and presented the ability of natural analogs of quercetin having superior antioxidant, anti-inflammatory and antiviral effects than the original molecule.

RESULTS

This review allowed the identification of relevant key structure-activity relationship elements and highlight approaches on the mechanisms governing the antioxidant, antiviral and anti-inflammatory activities.

CONCLUSION

Through a critical analysis of the literature, flavonols and more precisely quercetin derivatives reviewed and found to act simultaneously on inflammation, virus and oxidative stress, three key factors that may lead to life threatening diseases.

Natural Products Targeting Liver X Receptors or Farnesoid X Receptor

Nuclear receptors (NRs) are a superfamily of transcription factors induced by ligands and also function as integrators of hormonal and nutritional signals. Among NRs, the liver X receptors (LXRs) and farnesoid X receptor (FXR) have been of significance as targets for the treatment of metabolic syndrome-related diseases. In recent years, natural products targeting LXRs and FXR have received remarkable interests as a valuable source of novel ligands encompassing diverse chemical structures and bioactive properties. This review aims to survey natural products, originating from terrestrial plants and microorganisms, marine organisms, and marine-derived microorganisms, which could influence LXRs and FXR. In the recent two decades (2000-2020), 261 natural products were discovered from natural resources such as LXRs/FXR modulators, 109 agonists and 38 antagonists targeting LXRs, and 72 agonists and 55 antagonists targeting FXR. The docking evaluation of desired natural products targeted LXRs/FXR is finally discussed. This comprehensive overview will provide a reference for future study of novel LXRs and FXR agonists and antagonists to target human diseases, and attract an increasing number of professional scholars majoring in pharmacy and biology with more in-depth discussion.

Old wine in new bottles: Kaempferol is a promising agent for treating the trilogy of liver diseases

As a source of various compounds, natural products have long been important and valuable for drug development. Kaempferol (KP) is the most common flavonol with bioactive activity and has been extracted from many edible plants and traditional Chinese medicines. It has a wide range of pharmacological effects on inflammation, oxidation, and tumour and virus regulation. The liver is an important organ and is involved in metabolism and activity. Because the pathological process of liver diseases is extremely complicated, liver diseases involving ALD, NASH, liver fibrosis, and HCC are often complicated and difficult to treat. Fortunately, there have been many reports that KP has a good pharmacological effect on a series of complex liver diseases. To fully understand the mechanism of KP and provide new ideas for its clinical application in the treatment of liver diseases, this article reviews the pharmacological mechanism and potential value of KP in different studies involving various liver diseases. In the trilogy of liver disease, high concentrations of ROS stimulate peroxidation and activate the inflammatory signal cascade, which involves signalling pathways such as MAPK/JAK-STAT/PERK/Wnt/Hipp, leading to varying degrees of cell degradation and liver damage. The development of liver disease is promoted in an inflammatory environment, which is conducive to the activation of TGF-β1, leading to increased expression of pro-fibrosis and pro-inflammatory genes. Inflammation and oxidative stress promote the formation of tumour microenvironments, and uncontrolled autophagy of cancer cells further leads to the development of liver cancer. The main pathway in this process is AMPK/PTEN/PI3K-Akt/TOR. KP can not only protect liver parenchymal cells through a variety of antioxidant and anti-apoptotic mechanisms but also reduces the immune inflammatory response in the liver microenvironment, thereby preventing cell apoptosis; it can also inhibit the ER stress response, prevent inflammation and inhibit tumour growth. KP exerts multiple therapeutic effects on liver disease by regulating precise signalling targets and is expected to become an emerging therapeutic opportunity to treat liver disease in the future.

Quercetin and its derivates as antiviral potentials: A comprehensive review

Quercetin, widely distributed in fruits and vegetables, is a flavonoid known for its antioxidant, antiviral, antimicrobial, and antiinflammatory properties. Several studies highlight the potential use of quercetin as an antiviral, due to its ability to inhibit the initial stages of virus infection, to be able to interact with proteases important for viral replication, and to reduce inflammation caused by infection. Quercetin could also be useful in combination with other drugs to potentially enhance the effects or synergistically interact with them, in order to reduce their side effects and related toxicity. Since there is no comprehensive compilation about antiviral activities of quercetin and derivates, the aim of this review is providing a summary of their antiviral activities on a set of human viral infections along with mechanisms of action. Thus, the following family of viruses are examined: Flaviviridae, Herpesviridae, Orthomyxoviridae, Coronaviridae, Hepadnaviridae, Retroviridae, Picornaviridae, Pneumoviridae, and Filoviridae.

The Chinese Herbal Prescription JieZe-1 Inhibits Membrane Fusion and the Toll-like Receptor Signaling Pathway in a Genital Herpes Mouse Model

Chinese herbal prescription JieZe-1 is effective for genital herpes with no visible adverse effects clinically. It showed an excellent anti-HSV-2 effect in vitro. However, its mechanism of anti-HSV-2 effect in vivo remains unclear. This study was designed to evaluate the anti-HSV-2 effect of JieZe-1 and berberine in a genital herpes mouse model and explore the underlying mechanism. The fingerprint of JieZe-1 was determined by high-performance liquid chromatography. First, we optimized a mouse model of genital herpes. Next, the weight, symptom score, morphological changes, viral load, membrane fusion proteins, critical proteins of the Toll-like receptor signaling pathway, cytokines, and immune cells of vaginal tissue in mice at different time points were measured. Finally, we treated the genital herpes mouse model with JieZe-1 gel (2.5, 1.5, and 0.5 g/ml) and tested the above experimental indexes at 12 h and on the 9th day after modeling. JieZe-1 improved the symptoms, weight, and histopathological damage of genital herpes mice, promoted the keratin repair of tissues, and protected organelles to maintain the typical morphology of cells. It downregulated the expression of membrane fusion proteins, critical proteins of the Toll-like receptor signaling pathway, cytokines, and immune cells. The vaginal, vulvar, and spinal cord viral load and vaginal virus shedding were also significantly reduced. In summary, JieZe-1 shows significant anti-HSV-2 efficacy in vivo. The mechanism is related to the inhibition of membrane fusion, the Toll-like receptor signaling pathway, inflammatory cytokines, and cellular immunity. However, berberine, the main component of JieZe-1 monarch medicine, showed no efficacy at a concentration of 891.8 μM (0.3 mg/ml).

Hepatitis C virus induces oxidation and degradation of apolipoprotein B to enhance lipid accumulation and promote viral production

Hepatitis C virus (HCV) infection induces the degradation and decreases the secretion of apolipoprotein B (ApoB). Impaired production and secretion of ApoB-containing lipoprotein is associated with an increase in hepatic steatosis. Therefore, HCV infection-induced degradation of ApoB may contribute to hepatic steatosis and decreased lipoprotein secretion, but the mechanism of HCV infection-induced ApoB degradation has not been completely elucidated. In this study, we found that the ApoB level in HCV-infected cells was regulated by proteasome-associated degradation but not autophagic degradation. ApoB was degraded by the 20S proteasome in a ubiquitin-independent manner. HCV induced the oxidation of ApoB via oxidative stress, and oxidized ApoB was recognized by the PSMA5 and PSMA6 subunits of the 20S proteasome for degradation. Further study showed that ApoB was degraded at endoplasmic reticulum (ER)-associated lipid droplets (LDs) and that the retrotranslocation and degradation of ApoB required Derlin-1 but not gp78 or p97. Moreover, we found that knockdown of ApoB before infection increased the cellular lipid content and enhanced HCV assembly. Overexpression of ApoB-50 inhibited lipid accumulation and repressed viral assembly in HCV-infected cells. Our study reveals a novel mechanism of ApoB degradation and lipid accumulation during HCV infection and might suggest new therapeutic strategies for hepatic steatosis.

Hepatitis C virus (HCV) infection induces the degradation of apolipoprotein B (ApoB), which is the primary apolipoprotein in low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL). Impaired production and secretion of ApoB-containing lipoprotein is associated with an increase in hepatic steatosis. Thus, ApoB degradation might contribute to HCV infection-induced fatty liver. Here, we found that ApoB was not degraded through endoplasmic reticulum-associated degradation (ERAD) or autophagy, as reported previously. Instead, HCV infection induced ApoB oxidation through oxidative stress, and oxidatively damaged ApoB could be recognized and directly degraded by the 20S proteasome. We also found that ApoB was retrotranslocated from the endoplasmic reticulum (ER) to lipid droplets (LDs) for degradation. Through overexpression of ApoB-50, which can mediate the assembly and secretion of LDL and VLDL, we confirmed that ApoB degradation contributed to hepatocellular lipid accumulation induced by HCV infection. Additionally, expression of ApoB-50 impaired HCV production due to the observed decrease in lipid accumulation. In this study, we identified new mechanisms of ApoB degradation and HCV-induced lipid accumulation, and our findings might facilitate the development of novel therapeutic strategies for HCV infection-induced fatty liver.

Chronic liver disease and oxidative stress - a narrative review

Introduction: Oxidative stress underlies the pathophysiology of various etiologies of chronic liver disease and contributes to the development of hepatocarcinogenesis.Areas covered: This review focuses on the impact of oxidative stress in various etiologies of chronic liver disease such as alcoholic liver disease (ALD), nonalcoholic steatohepatitis (NASH), hepatitis B virus (HBV), and hepatitis C virus (HCV) infection. The efficacy of antioxidants in laboratory, animal, and clinical studies in chronic liver disease is also reviewed.Expert opinion: Currently, there are limited targeted pharmacotherapeutics for NASH and no pharmacotherapeutics for ALD and antioxidant supplementation may be useful in these conditions to improve liver function and reverse fibrosis. Antioxidants may also be used in patients with HBV or HCV infection to supplement antiviral therapies. Specific genotypes of antioxidant and prooxidant genes render patients more susceptible to liver cirrhosis and hepatocellular carcinoma while other individual characteristics like age, genotype, and metabolomic profiling can influence the efficacy of antioxidants on CLD. More research needs to be done to establish the safety, efficacy, and dosage of antioxidants and to establish the ideal patient profile that will benefit the most from antioxidant treatment.

Recent Developments in the Use of Kinase Inhibitors for Management of Viral Infections

Kinases are a group of therapeutic targets involved in the progression of numerous diseases, including cancer, rheumatoid arthritis, Alzheimer's disease, and viral infections. The majority of approved antiviral agents are inhibitors of virus-specific targets that are encoded by individual viruses. These inhibitors are narrow-spectrum agents that can cause resistance development. Viruses are dependent on host cellular proteins, including kinases, for progression of their life-cycle. Thus, targeting kinases is an important therapeutic approach to discovering broad-spectrum antiviral agents. As there are a large number of FDA approved kinase inhibitors for various indications, their repurposing for viral infections is an attractive and time-sparing strategy. Many kinase inhibitors, including baricitinib, ruxolitinib, imatinib, tofacitinib, pacritinib, zanubrutinib, and ibrutinib, are under clinical investigation for COVID-19. Herein, we discuss FDA approved kinase inhibitors, along with a repertoire of clinical/preclinical stage kinase inhibitors that possess antiviral activity or are useful in the management of viral infections.

Natural products for the management of the hepatitis C virus: a biochemical review

Chronic hepatitis C virus (HCV) infection is a significant public health problem, with a worldwide prevalence of approximately 170 million. Current therapy for HCV infection includes the prolonged administration of a combination of ribavirin and PEGylated interferon-α, for over a decade. This regimen is expensive and often associated with a poor antiviral response and unwanted side effects. A highly effective combination treatment is likely required for the future management of HCV infections and entry inhibitors could play an important role. Currently, no entry inhibitor has been licensed for the prophylactic treatment of hepatitis C. Therefore, additional agents that combat HCV infection are urgently needed and must be developed. Many phytochemical constituents have been identified that display considerable inhibition of HCV at some stage of the life cycle. This review will summarise the current state of knowledge on natural products and their possible activities in the context of HCV infection.

Synergistic effect of phytochemicals on cholesterol metabolism and lipid accumulation in HepG2 cells

Background

Crocin (CRO), chlorogenic acid (CGA), geniposide (GEN), and quercetin (QUE) are all natural compounds with anti-obesity properties, in particular, hypolipidemic effects, which have been widely used for the treatment of obesity-related metabolic diseases. However, it is not yet known whether these compounds interact synergistically. Here, we investigated the effects and molecular mechanisms of CRO, CGA, GEN, QUE, and a combination of all four compounds (CCGQ), on lipid accumulation in human hepatoma (HepG2 cells).

Methods

The optimal concentration of CRO, CGA, GEN, QUE to stimulate HepG2 cells proliferation was determined using MTT assay. HepG2 cells were pretreated with 10 μmol/L simvastatin, 1 μmol/L CRO, 30 μmol/L CGA, 10 μmol/L GEN, 10 μmol/L QUE, and CCGQ (a combination of 1 μmol/L CRO, 30 μmol/L CGA, 10 μmol/L GEN, and 10 μmol/L QUE) for 24 or 48 h. Oil red O staining and extracellular TC and TG levels were detected. The RT-PCR was used to observe on cholesterol metabolism-related gene expression. Immunocytochemistry and western-blot assayed the 3-hydroxy-3-methylglutaryl-coenzyme (HMGCR) protein expression in HepG2 cells.

Results

Compared to those of control, we demonstrated that treating HepG2 cells for 48 h with CCGQ resulted in a strong synergistic effect, causing a marked decrease in lipid deposition in comparison to individual treatments, in both triglyceride and total cholesterol (CRO, 5.74- and 1.49-folds; CGA, 3.38- and 1.12-folds; GEN, 4.04- and 1.44-folds; QUE, 3.36- and 1.24-folds; simvastatin, 5.49- and 1.83-folds; and CCGQ, 7.75- and 2.20-folds), and Oil red O staining assays. In addition, CCGQ treatment increased ATP-binding cassette transporter (ABCA1), cholesterol 7α-hydroxylase (CYP7A1), and AMP-activated protein kinase 2α (AMPKα2) mRNA expression, while decreasing sterol regulatory element binding protein 2 (SREBP2), and liver X receptor alpha (LXRα) mRNA expression. Notably, CCGQ was more effective in decreasing HMGCR expression than the individual treatments.

Conclusion

The CCGQ combination has potential, both as a complementary therapy for hyperlipemia, and in preventing further obesity-related complications.

Phytochemicals That Influence Gut Microbiota as Prophylactics and for the Treatment of Obesity and Inflammatory Diseases

Gut microbiota (GM) plays several crucial roles in host physiology and influences several relevant functions. In more than one respect, it can be said that you “feed your microbiota and are fed by it.” GM diversity is affected by diet and influences metabolic and immune functions of the host's physiology. Consequently, an imbalance of GM, or dysbiosis, may be the cause or at least may lead to the progression of various pathologies such as infectious diseases, gastrointestinal cancers, inflammatory bowel disease, and even obesity and diabetes. Therefore, GM is an appropriate target for nutritional interventions to improve health. For this reason, phytochemicals that can influence GM have recently been studied as adjuvants for the treatment of obesity and inflammatory diseases. Phytochemicals include prebiotics and probiotics, as well as several chemical compounds such as polyphenols and derivatives, carotenoids, and thiosulfates. The largest group of these comprises polyphenols, which can be subclassified into four main groups: flavonoids (including eight subgroups), phenolic acids (such as curcumin), stilbenoids (such as resveratrol), and lignans. Consequently, in this review, we will present, organize, and discuss the most recent evidence indicating a relationship between the effects of different phytochemicals on GM that affect obesity and/or inflammation, focusing on the effect of approximately 40 different phytochemical compounds that have been chemically identified and that constitute some natural reservoir, such as potential prophylactics, as candidates for the treatment of obesity and inflammatory diseases.

Plant-derived antivirals against hepatitis c virus infection

Hepatitis C virus (HCV) infection is a worldwide public health burden and it is estimated that 185 million people are or have previously been infected worldwide. There is no effective vaccine for prevention of HCV infection; however, a number of drugs are available for the treatment of infection. The availability of direct-acting antivirals (DAAs) has dramatically improved therapeutic options for HCV genotype 1. However, the high costs and potential for development of resistance presented by existing treatment demonstrate the need for the development of more efficient new antivirals, or combination of therapies that target different stages of the viral lifecycle. Over the past decades, there has been substantial study of compounds extracted from plants that have activity against a range of microorganisms that cause human diseases. An extensive variety of natural compounds has demonstrated antiviral action worldwide, including anti-HCV activity. In this context, plant-derived compounds can provide an alternative approach to new antivirals. In this review, we aim to summarize the most promising plant-derived compounds described to have antiviral activity against HCV.

The role of PTEN - HCV core interaction in hepatitis C virus replication

Hepatitis C virus (HCV) infection leads to severe liver diseases including hepatocellular carcinoma (HCC). Phosphatase and tensin homolog deleted on chromosome 10 (PTEN), a tumour suppressor, is frequently mutated or deleted in HCC tumors. PTEN has previously been demonstrated to inhibit HCV secretion. In this study, we determined the effects of PTEN on the other steps in HCV life cycle, including entry, translation, and replication. We showed that PTEN inhibits HCV entry through its lipid phosphatase activity. PTEN has no effect on HCV RNA translation. PTEN decreases HCV replication and the protein phosphatase activity of PTEN is essential for this function. PTEN interacts with the HCV core protein and requires R50 in domain I of HCV core and PTEN residues 1–185 for this interaction. This interaction is required for PTEN-mediated inhibition of HCV replication. This gives rise to a reduction in PTEN levels and intracellular lipid abundance, which may in turn regulate HCV replication. HCV core domain I protein increases the lipid phosphatase activity of PTEN in an in vitro assay, suggesting that HCV infection can also regulate PTEN. Taken together, our results demonstrated an important regulatory role of PTEN in the HCV life cycle.

Apigenin Attenuates Adriamycin-Induced Cardiomyocyte Apoptosis via the PI3K/AKT/mTOR Pathway

Treatment with Adriamycin (ADR) is one of the major causes of chemotherapy-induced cardiotoxicity and therefore is the principal limiting factor in the effectiveness of chemotherapy for cancer patients. Apigenin (API) has been shown to play a cardioprotective role. The present study examined the effect of API on ADR-induced cardiotoxicity in mice. Sixty male Kunming mice were randomly divided into 4 groups: a control group, ADR model group, low-dose API treatment group (125 mg·kg⁻¹), and high-dose API treatment group (250 mg·kg⁻¹). Blood samples were taken to evaluate a spectrum of myocardial enzymes. Cardiomyocyte apoptosis was measured using a TUNEL assay, and cardiomyocyte autophagy was observed using electron microscopy. Moreover, apoptosis-related proteins, such as Bax and Bcl-2, autophagy-related proteins, including Beclin1 and LC3B, and PI3K/AKT/mTOR pathway-related proteins were examined with western blot. Our results demonstrate that ADR caused an increase in the serum levels of cardiac injury markers and enhanced cardiomyocyte apoptosis and autophagy. API administration prevented the effects associated with ADR-induced cardiotoxicity in mice and inhibited ADR-induced apoptosis and autophagy. API also promoted PI3K/AKT/mTOR pathway activity in ADR-treated mice. In conclusion, API may have a protective effect against ADR-induced cardiotoxicity by inhibiting apoptosis and autophagy via activation of the PI3K/AKT/mTOR pathway.

Autotaxin-lysophosphatidic acid receptor signalling regulates hepatitis C virus replication

BACKGROUND & AIMS

Chronic hepatitis C is a global health problem with an estimated 170 million hepatitis C virus (HCV) infected individuals at risk of progressive liver disease and hepatocellular carcinoma (HCC). Autotaxin (ATX, gene name: ENPP2) is a phospholipase with diverse roles in the physiological and pathological processes including inflammation and oncogenesis. Clinical studies have reported increased ATX expression in chronic hepatitis C, however, the pathways regulating ATX and its role in the viral life cycle are not well understood.

METHODS

In vitro hepatocyte and ex vivo liver culture systems along with chimeric humanized liver mice and HCC tissue enabled us to assess the interplay between ATX and the HCV life cycle.

RESULTS

HCV infection increased hepatocellular ATX RNA and protein expression. HCV infection stabilizes hypoxia inducible factors (HIFs) and we investigated a role for these transcription factors to regulate ATX. In vitro studies show that low oxygen increases hepatocellular ATX expression and transcriptome analysis showed a positive correlation between ATX mRNA levels and hypoxia gene score in HCC tumour tissue associated with HCV and other aetiologies. Importantly, inhibiting ATX-lysophosphatidic acid (LPA) signalling reduced HCV replication, demonstrating a positive role for this phospholipase in the viral life cycle. LPA activates phosphoinositide-3-kinase that stabilizes HIF-1α and inhibiting the HIF signalling pathway abrogates the pro-viral activity of LPA.

CONCLUSIONS

Our data support a model where HCV infection increases ATX expression which supports viral replication and HCC progression.

LAY SUMMARY

Chronic hepatitis C is a global health problem with infected individuals at risk of developing liver disease that can progress to hepatocellular carcinoma. Autotaxin generates the biologically active lipid lysophosphatidic acid that has been reported to play a tumorigenic role in a wide number of cancers. In this study we show that hepatitis C virus infection increases autotaxin expression via hypoxia inducible transcription factor and provides an environment in the liver that promotes fibrosis and liver injury. Importantly, we show a new role for lysophosphatidic acid in positively regulating hepatitis C virus replication.

GRIM-19 Restricts HCV Replication by Attenuating Intracellular Lipid Accumulation

Gene-associated with retinoid-interferon-induced mortality 19 (GRIM-19) targets multiple signaling pathways involved in cell death and growth. However, the role of GRIM-19 in the pathogenesis of hepatitis virus infections remains unexplored. Here, we investigated the restrictive effects of GRIM-19 on the replication of hepatitis C virus (HCV). We found that GRIM-19 protein levels were reduced in HCV-infected Huh7 cells and Huh7 cells harboring HCV replicons. Moreover, ectopically expressed GRIM-19 caused a reduction in both intracellular viral RNA levels and secreted viruses in HCVcc-infected cell cultures. The restrictive effect on HCV replication was restored by treatment with siRNA against GRIM-19. Interestingly, GRIM-19 overexpression did not alter the level of phosphorylated STAT3 or its subcellular distribution. Strikingly, forced expression of GRIM-19 attenuated an increase in intracellular lipid droplets after oleic acid (OA) treatment or HCVcc infection. GRIM-19 overexpression abrogated fatty acid-induced upregulation of sterol regulatory element-binding transcription factor-1 (SREBP-1c), resulting in attenuated expression of its target genes such as fatty acid synthase (FAS) and acetyl CoA carboxylase (ACC). Treatment with OA or overexpression of SREBP-1c in GRIM-19-expressing, HCVcc-infected cells restored HCV replication. Our results suggest that GRIM-19 interferes with HCV replication by attenuating intracellular lipid accumulation and therefore is an anti-viral host factor that could be a promising target for HCV treatment.

Biophysical characterization of the interaction between M2-1 protein of hRSV and quercetin

hRSV is the major causative agent of acute respiratory infections. Among its eleven proteins, M2-1 is a transcription antiterminator, making it an interesting target for antivirals. Quercetin is a flavonol which inhibits some virus infectivity and replication. In the present work, the M2-1 gene was cloned, expressed and the protein was purified. Thermal stability and secondary structure were analyzed by circular dichroism and the interaction with Quercetin was evaluated by fluorescence spectroscopy. Molecular docking experiments were performed to understand this mechanism of interaction. The purified protein is mainly composed of α-helix, with a melting temperature of 328.6K (≈55°C). M2-1 titration with Quercetin showed it interacts with two sites, one with a strong constant association K1 (site 1≈1.5×10⁶M^-1) by electrostatic interactions, and another with a weak constant association K2 (site 2≈1.1×10⁵M^-1) by a hydrophobic interaction. Ligand's docking shows it interacts with the N-terminus face in a more polar pocket and, between the domains of oligomerization and RNA and P protein interaction, in a more hydrophobic pocket, as predicted by experimental data. Therefore, we postulated this ligand could be interacting with important domains of the protein, avoiding viral replication and budding.

An extract from Taxodium distichum targets hemagglutinin- and neuraminidase-related activities of influenza virus in vitro

Influenza virus remains an emerging virus and causes pandemics with high levels of fatality. After screening different plant extracts with potential anti-influenza activity, a water extract of Taxodium distichum stems (TDSWex) showed excellent activity against influenza viruses. The EC₅₀ of TDSWex was 0.051 ± 0.024 mg/mL against influenza virus A/WSN/33. TDSWex had excellent antiviral efficacy against various strains of human influenza A and B viruses, particularly oseltamivir-resistant clinical isolates and a swine-origin influenza strain. We observed that the synthesis of viral RNA and protein were inhibited in the presence of TDSWex. The results of the time-of-addition assay suggested that TDSWex inhibited viral entry and budding. In the hemagglutination inhibition assay, TDSWex inhibited the hemagglutination of red blood cells, implying that the extract targeted hemagglutin-related functions such as viral entry. In the attachment and penetration assay, TDSWex showed antiviral activity with EC₅₀s of 0.045 ± 0.026 and 0.012 ± 0.003 mg/mL, respectively. In addition, TDSWex blocked neuraminidase activity. We conclude that TDSWex has bimodal activities against both hemagglutinin and neuraminidase during viral replication.

Anti-Cancer Effect of Quercetin in Xenograft Models with EBV-Associated Human Gastric Carcinoma

Licorice extracts have been widely used in herbal and folk medications. Glycyrrhiza contains diverse range of biological compounds including triterpenes (glycyrrhizin, glycyrrhizic acid) and flavonoids (quercetin, liquiritin, liquiritigenin, glabridin, licoricidin, isoliquiritigenin). The flavonoids in licorice are known to have strong anti-cancer activities. Quercetin, the most abundant flavonoid, has been shown to have anti-ulcer, anti-cancer, antioxidant, and anti-inflammatory properties. Latent Epstein-Barr virus (EBV) infection can lead to serious malignancies, such as, Burkitt’s lymphoma, Hodgkin’s disease and gastric carcinoma(GC), and (Epstein-Barr virus associated gastric carcinoma) EBVaGC is one of the most common EBV-associated cancers. In this study, the authors first examined the anti-cancer effects of quercetin and isoliquiritigenin in vivo xenograft animal models implanted with EBV(+) human gastric carcinoma (SNU719) or EBV(−) human gastric carcinoma (MKN74), and then explored the molecular mechanisms responsible for their anti-cancer activities. The results obtained showed that anti-cancer effect of quercetin was greater than isoliquiritigenin in mice injected with EBV(+) human gastric carcinoma (SNU719) cells. On the other hand, quercetin and isoliquiritigenin had similar anti-cancer effects in mice injected with EBV(−) human gastric carcinoma (MKN74) cells. Interestingly, quercetin inhibited EBV viral protein expressions, including EBNA-1 and LMP-2 proteins in tumor tissues from mice injected with EBV(+) human gastric carcinoma. Quercetin more effectively induced p53-dependent apoptosis than isoliquiritigenin in EBV(+) human gastric carcinoma, and this induction was correlated with increased expressions of the cleaved forms of caspase-3, -9, and Parp. In EBV(−)human gastric carcinoma (MKN74), both quercetin and isoliquiritigenin induced the expressions of p53, Bax, and Puma and the cleaved forms of caspase-3 and -9 and Parp at similar levels.

The Flavone Luteolin Inhibits Liver X Receptor Activation

Luteolin is a dietary flavonoid with medicinal properties including antioxidant, antimicrobial, anticancer, antiallergic, and anti-inflammatory. However, the effect of luteolin on liver X receptors (LXRs), oxysterol sensors that regulate cholesterol homeostasis, lipogenesis, and inflammation, has yet to be studied. To unveil the potential of luteolin as an LXRα/β modulator, we investigated by real-time RT-PCR the expression of LXR-target genes, namely, sterol regulatory element binding protein 1c (SREBP-1c) in hepatocytes and ATP-binding cassette transporter (ABC)A1 in macrophages. The lipid content of hepatocytes was evaluated by Oil Red staining. The results demonstrated, for the first time, that luteolin abrogated the LXRα/β agonist-induced LXRα/β transcriptional activity and, consequently, inhibited SREBP-1c expression, lipid accumulation, and ABCA1 expression. Therefore, luteolin could abrogate hypertriglyceridemia associated with LXR activation, thus presenting putative therapeutic effects in diseases associated with deregulated lipid metabolism, such as hepatic steatosis, cardiovascular diseases, and diabetes.

Quercetin-induced apoptosis prevents EBV infection

Epstein-Barr virus (EBV) is a human gamma-1 herpesvirus that establishes a lifelong latency in over 90% of the world's population. During latency, virus exists predominantly as a chromatin-associated, multicopy episome in the nuclei of a variety of tumor cells derived from B cells, T cells, natural killer (NK) cells, and epithelial cells. Licorice is the root of Glycyrrhiza uralensis or G. glabra that has traditionally cultivated in eastern part of Asia. Licorice was reported to have anti-viral, anti-inflammatory, anti-atopic, hepatoprotective, anti-neurodegenerative, anti-tumor, anti-diabetic effects and so forth. Quercetin and isoliquiritigenin are produced from licorice and highly similar in molecular structure. They have diverse bioactive effects such as antiviral activity, anti-asthmatic activity, anti-cancer activity, anti-inflammation activity, monoamine-oxidase inhibitor, and etc. To determine anti-EBV and anti-EBVaGC (Epstein-Barr virus associated gastric carcinoma) effects of licorice, we investigated antitumor and antiviral effects of quercetin and isoliquiritigenin against EBVaGC. Although both quercetin and isoliquiritigenin are cytotoxic to SNU719 cells, quercetin induced more apoptosis in SNU719 cells than isoliquiritigenin, more completely eliminated DNMT1 and DNMT3A expressions than isoliquiritigenin, and more strongly affects the cell cycle progression of SNU719 than isoliquiritigenin. Both quercetin and isoliquiritigenin induce signal transductions to stimulate apoptosis, and induce EBV gene transcription. Quercetin enhances frequency of F promoter use, whereas isoliquiritigenin enhances frequency of Q promoter use. Quercetin reduces EBV latency, whereas isoliquiritigenin increases the latency. Quercetin increases more the EBV progeny production, and inhibits more EBV infection than isoliquiritigenin. These results indicate that quercetin could be a promising candidate for antiviral and antitumor agents against EBV and human gastric carcinoma.

Prenatal caffeine exposure induces a poor quality of articular cartilage in male adult offspring rats via cholesterol accumulation in cartilage

Epidemiological investigations indicate that osteoarthritis is associated with intrauterine growth retardation (IUGR) and abnormal cholesterol metabolism. Our previous studies showed that prenatal caffeine exposure (PCE) induced chondrogenesis retardation in IUGR offspring rats. The current study sought to investigate the effects of PCE on male IUGR offspring rats’ articular cartilage, and the mechanisms associated with abnormal cholesterol metabolism. Based on the results from both male fetal and adult fed a high-fat diet (HFD) studies of rats that experienced PCE (120 mg/kg.d), the results showed a poor quality of articular cartilage and cholesterol accumulation in the adult PCE group. Meanwhile, the serum total cholesterol and low-density lipoprotein-cholesterol concentrations were increased in adult PCE offspring. We also observed lower expression of insulin-like growth factor1 (IGF1) and impaired cholesterol efflux in adult articular cartilage. Furthermore, the expression of cartilage functional genes, components of the IGF1 signaling pathway and cholesterol efflux pathway related genes were decreased in PCE fetal cartilage. In conclusion, PCE induced a poor quality of articular cartilage in male adult offspring fed a HFD. This finding was shown to be due to cholesterol accumulation in the cartilage, which may have resulted from intrauterine reduced activity of the IGF1 signaling pathway.

Y-Box Binding Protein 1 Stabilizes Hepatitis C Virus NS5A via Phosphorylation-Mediated Interaction with NS5A To Regulate Viral Propagation

Replication of hepatitis C virus (HCV) is dependent on virus-encoded proteins and numerous cellular factors. DDX3 is a well-known host cofactor of HCV replication. In this study, we investigated the role of a DDX3-interacting protein, Y-box binding protein 1 (YB-1), in the HCV life cycle. Both YB-1 and DDX3 interacted with the viral nonstructural protein NS5A. During HCV infection, YB-1 partially colocalized with NS5A and the HCV replication intermediate double-stranded RNA (dsRNA) in HCV-infected Huh-7.5.1 cells. Despite sharing the same interacting partners, YB-1 participated in HCV RNA replication but was dispensable in steady-state HCV RNA replication, different from the action of DDX3. Moreover, knockdown of YB-1 in HCV-infected cells prevented infectious virus production and reduced the ratio of hyperphosphorylated (p58) to hypophosphorylated (p56) forms of NS5A, whereas DDX3 silencing did not affect the ratio of the p58 and p56 phosphoforms of NS5A. Interestingly, silencing of YB-1 severely reduced NS5A protein stability in NS5A-ectopically expressing, replicon-containing, and HCV-infected cells. Furthermore, mutations of serine 102 of YB-1 affected both YB-1-NS5A interaction and NS5A-stabilizing activity of YB-1, indicating that this Akt phosphorylation site of YB-1 plays an important role in stabilizing NS5A. Collectively, our results support a model in which the event of YB-1 phosphorylation-mediated interaction with NS5A results in stabilizing NS5A to sustain HCV RNA replication and infectious HCV production. Overall, our study may reveal a new aspect for the development of novel anti-HCV drugs.

IMPORTANCE

Chronic hepatitis C virus (HCV) infection induces liver cirrhosis and hepatocellular carcinoma. The viral nonstructural protein NS5A co-opting various cellular signaling pathways and cofactors to support viral genome replication and virion assembly is a new strategy for anti-HCV drug development. NS5A phosphorylation is believed to modulate switches between different stages of the HCV life cycle. In this study, we identified the cellular protein YB-1 as a novel NS5A-interacting protein. YB-1 is a multifunctional protein participating in oncogenesis and is an oncomarker of hepatocellular carcinoma (HCC). We found that YB-1 protects NS5A from degradation and likely regulates NS5A phosphorylation through its phosphorylation-dependent interaction with NS5A, which might be controlled by HCV-induced signaling pathways. Our observations suggest a model in which HCV modulates NS5A level and the ratio of the p58 and p56 phosphoforms for efficient viral propagation via regulation of cellular signaling inducing YB-1 phosphorylation. Our finding may provide new aspects for developing novel anti-HCV drugs.

Induction of cellular and molecular immunomodulatory pathways by vitamin A and flavonoids

INTRODUCTION

A detailed study of reports on the immunomodulatory properties of vitamin A and select flavonoids may pave the way for using these natural compounds or compounds with similar structures in novel drug and vaccine designs against infectious and autoimmune diseases and cancers.

AREAS COVERED

Intracellular transduction pathways, cellular differentiation and functional immunomodulatory responses have been reviewed. The reported studies encompass in vitro, in vivo preclinical and clinical studies that address the role of vitamin A and select flavonoids in induction of innate and adaptive B- and T-cell responses, including TH1, TH2 and regulatory T cells (Treg).

EXPERT OPINION

While the immunomodulatory role of vitamin A, and related compounds, is well-established in many preclinical studies, its role in humans has begun to gain wider acceptance. In contrast, the role of flavonoids is mostly controversial in clinical trials, due to the diversity of the various classes of these compounds, and possibly due to the purity and the selected doses of the compounds. However, current preclinical and clinical studies warrant further detailed studies of these promising immunomodulatory compounds.

Taxifolin protects against cardiac hypertrophy and fibrosis during biomechanical stress of pressure overload

Cardiac hypertrophy is a key pathophysiological component to biomechanical stress, which has been considered to be an independent and predictive risk factor for adverse cardiovascular events. Taxifolin (TAX) is a typical plant flavonoid, which has long been used clinically for treatment of cardiovascular and cerebrovascular diseases. However, very little is known about whether TAX can influence the development of cardiac hypertrophy. In vitro studies, we found that TAX concentration-dependently inhibited angiotensin II (Ang II) induced hypertrophy and protein synthesis in cardiac myocytes. Then we established a mouse model by transverse aortic constriction (TAC) to further confirm our findings. It was demonstrated that TAX prevented pressure overload induced cardiac hypertrophy in mice, as assessed by ventricular mass/body weight, echocardiographic parameters, myocyte cross-sectional area, and the expression of ANP, BNP and β-MHC. The excess production of reactive oxygen species (ROS) played critical role in the development of cardiac hypertrophy. TAX arrested oxidative stress and decreased the expression of 4-HNE induced by pressure overload. Moreover, TAX negatively modulated TAC-induced phosphorylation of ERK1/2 and JNK1/2. Further studies showed that TAX significantly attenuated left ventricular fibrosis and collagen synthesis through abrogating the phosphorylation of Smad2 and Smad2/3 nuclear translocation. These results demonstrated that TAX could inhibit cardiac hypertrophy and attenuate ventricular fibrosis after pressure overload. These beneficial effects were at least through the inhibition of the excess production of ROS, ERK1/2, JNK1/2 and Smad signaling pathways. Therefore, TAX might be a potential candidate for the treatment of cardiac hypertrophy and fibrosis.

The acetyl-CoA carboxylase enzyme: a target for cancer therapy?

As a rate-limiting enzyme, the acetyl-CoA carboxylase (ACC) is essential for fatty acid synthesis. Traditionally, the ACC has been a target of metabolic syndrome and obesity. Recent research has demonstrated that malignant tumors have a high energy flow, thus having a great ability to synthesize fatty acids. ACCs are occasionally found to be overexpressed in cancer cells, and using chemical or RNA interference to inhibit ACC can lead to cancer cell cycle arrest and apoptosis. This suggests that ACC and relative fatty acids may be critical for the survival of cancer cells. In this review, we summarize the role of ACC in tumor development. We also discuss the signaling pathways possibly affected by ACC, which may give insight into future research for cancer therapy.

Quercetin ameliorates dysregulation of lipid metabolism genes via the PI3K/AKT pathway in a diet-induced mouse model of nonalcoholic fatty liver disease

SCOPE

Flavonoids and related compounds seem to have favorable effects on nonalcoholic fatty liver disease (NAFLD) progression, although the exact mechanisms implicated are poorly understood. In this study, we aimed to investigate the effect of the flanovol quercetin on gene expression deregulation involved in the development of NAFLD, as well as the possible implication of phosphatidylinositol 3-kinase (PI3K)/AKT pathway modulation.

METHODS AND RESULTS

We used an in vivo model based on methionine- and choline-deficient (MCD) diet-fed mice and an in vitro model consisting of Huh7 cells incubated with MCD medium. MCD-fed mice showed classical pathophysiological characteristics of nonalcoholic steatohepatitis, associated with altered transcriptional regulation of fatty acid uptake- and trafficking-related gene expression, with increased lipoperoxidation. PI3K/AKT pathway was activated by MCD and triggered gene deregulation causing either activation or inhibition of all studied genes as demonstrated through cell incubation with the PI3K-inhibitor LY294002. Treatment with quercetin reduced AKT phosphorylation, and oxidative/nitrosative stress, inflammation and lipid metabolism-related genes displayed a tendency to normalize in both in vivo and in vitro models.

CONCLUSION

These results place quercetin as a potential therapeutic strategy for preventing NAFLD progression by attenuating gene expression deregulation, at least in part through PI3K/AKT pathway inactivation.

Application of recombinant Pediococcus acidilactici BD16 (fcs⁺/ech⁺) in malolactic fermentation

This study was conducted to enhance flavor characteristics of wine by malolactic fermentation using recombinant Pediococcus acidilactici BD16 (fcs (+)/ech (+)) encoding synthetic genes of feruloyl-CoA synthetase and enoyl-CoA hydratase. After malolactic fermentation, wine phenolics were characterized using LCMS-ESI technique and a significant improvement in the antioxidant activity and flavor characteristics of wine was observed due to increased concentration of cinnamic acid derivatives. This proof of concept study highlights the role of recombinant P. acidilactici BD16 (fcs (+)/ech (+)) in improving flavor as well as aroma of wine due to production of several phenolic derivatives during secondary fermentation. A novel metabolic pathway was predicted from mass spectral analysis data that indicates biotransformation of cinnamic acid and derivatives into apigenin, catechin, coniferyl aldehyde, cyanidin, hydroxybenzoic acids, laricitrin, luteolin, malvidin 3-glucoside, myricetin, naringenin, pelargonin, piceatannol, querecitin, and vanillin that not only increased the overall consumer appreciation but also improved nutritional and probably the therapeutic properties of wines. This is a first evidence-based study where role of recombinant P. acidilactici BD16 (fcs (+)/ech (+)) in the wine secondary fermentation has been elucidated.