Ferulic acid protects human umbilical vein endothelial cells from radiation induced oxidative stress by phosphatidylinositol 3-kinase and extracellular signal-regulated kinase pathways

Smoking, coffee intake, and Parkinson's disease: Potential protective mechanisms and components

Parkinson's disease (PD) is a common progressive neurodegenerative disease characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc). Environmental and lifestyle factors, such as smoking and coffee drinking, have been associated with a decreased risk for PD. However, the biological mechanisms underlying protective effects on PD are still not fully understood. It has been suggested that non-nicotine components in cigarette smoke and non-caffeine components in coffee may contribute to this protective effect. The aim of this review was to explore candidate molecules and mechanisms behind the effects of smoking and coffee drinking on PD by integrating findings from previous studies. By cross-referencing an index of tobacco constituents and a list of coffee constituents with existing literature on natural compounds and their structural analogs that show inhibitory activities against monoamine oxidase B, catechol O-methyltransferase, and α-synuclein fibrillation, we have identified tobacco and coffee components that inhibit these targets. Furthermore, tobacco and coffee components potentially play roles in suppressing neuroinflammation, activating the Nrf2 pathway as natural activators, and altering the gut microbiome. This review suggests that the phenolic compounds from tobacco and coffee investigated may contribute to the low incidence of PD in smokers and coffee drinkers, showing moderate to strong potential as therapeutic interventions. The current review suggests that multifunctional molecules found in coffee and cigarette smoke may have potential neuroprotective effects, but none of the data indicates that multifunctionality is required for these effects. This review will deepen our understanding of how smoking and coffee drinking are linked to a reduced risk of PD and will also be important in elucidating the mechanisms underlying the protective effects of smoking and coffee drinking on PD.

The Essential Role of Traditional Chinese Medicine Compounds in Regulating Recurrent Spontaneous Abortion by Inhibiting Oxidative Stress

Due to the lack of accurate registration of RSA and miscarriages, many early miscarriages are overlooked and not diagnosed or treated promptly in hospitals. This uncertainty in pathogenesis prevents clinicians from taking targeted therapeutic measures, leading to unsatisfactory treatment outcomes and placing a heavy burden on the patient's family and the healthcare system. Oxidative stress is present in embryonic development and affects the regulation of oxidative stress in pregnancy and the reproductive endocrine system. Oxidative stress injury is a significant pathogenesis of RSA, so improving the body's ability to resist oxidative stress injury is crucial in treating RSA. For patients with RSA, there is an urgent need for safe, efficient, and cost-effective anti-oxidative stress drugs, and there is growing evidence that treatment with Traditional Chinese medicine (TCM) can improve pregnancy success with fewer adverse effects. Many active ingredients for treating RSA are mainly derived from certain components of TCM, including flavonoids, phenols, and other compounds, which have been shown to treat RSA directly or indirectly by targeting anti-oxidative stress-related pathways. This article summarizes the experimental and clinical evidence of several common TCM compounds for treating RSA. It provides ideas and perspectives for further exploring the pathogenesis of RSA and TCM compounds for treating RSA.

The efficacy of sodium ferulate combination therapy in coronary heart disease: A systematic review and meta-analysis

BACKGROUND

Sodium ferulate (SF), a derivative of ferulic acid, is one of the active constituents in medicinal plants thought to be useful in fighting cardiovascular diseases. However, there still lacks a systematic review of the efficacy and safety of SF in treating coronary heart disease (CHD). It is therefore the purpose of this study to comprehensively review all clinical randomized controlled trials (RCTs) of SF in CHD to assess its efficacy and safety.

METHODS

All analysis is based on 8 databases as of February 2023, which includes 35 outcomes of RCTs that investigate the effect of SF combination therapy in CHD. The present study evaluates the quality and bias of selected literature by the Jadad scale and Cochrane Collaboration's tools, and also the quality of evidence by GRADE Profiler. Furthermore, it applies sensitivity analysis to assess the high heterogeneity impact of outcomes and conducted subgroup analysis to estimate the influence factors in these studies. The study protocol was set documented, and published beforehand in PROSPERO (Registration No.CRD42022348841).

RESULTS

The meta-analysis of 36 studies (with 3207 patients) shows that SF combined with conventional drugs has improved clinical effectiveness for patients with CHD [RR: 1.21 (95% CI 1.17,1.26); p < 0.00001]. Statistically significant results of meta-analyses are also seen in electrocardiography (ECG) efficacy, frequency of angina attacks, endothelium-dependent flow-mediated vasodilation (FMD), nitric oxide (NO), endothelin (ET), whole Blood low shear rate (LS), platelet aggregation test (PAgT), C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL6), triglyceride (TG). Adverse events are reported in 6 RCTs. By GRADE approaches, 2 outcomes (clinical efficacy, CRP) indicate a moderate quality of evidence, 17 outcomes indicate low quality of evidence, with the other 16 very low-quality.

CONCLUSION

SF combination therapy has a better curative effect than conventional therapy. However, due to items with low-quality evidence demonstrated in the study, the presence of clinical heterogeneity, and imprecision in partial outcome measures, all these led to limitations in the evidence of this study. Thus, the conclusion needs to be further verified by more in-depth research.

Effect of Angelica Sinensis extract on the angiogenesis of preovulatory follicles (F1-F3) in late-phase laying hens

In order to form follicles and ovulate normally, there must be abundant blood vessels. Angelica sinensis (Oliv.) Diels (AS), as a traditional Chinese medicinal herb, has the effects of tonifying the blood and activating the blood circulation. However, the effect of AS on angiogenesis in hen-follicles remains to be discovered. In this study, we identified vascular richness, granulosa layer thickness, expression of platelet endothelial cell adhesion molecule-1 (CD31) and the content of vascular endothelial growth factor A (VEGFA) in granulosa layers to elucidate the effect of AS extract on angiogenesis in preovulatory follicles (F1-F3) of late-phase laying hens (75 wk). Based on network pharmacology, we predicted beta-sitosterol, ferulic acid, and caffeic acid as the main active components of AS, and hypoxia-inducible factor-1α (HIF1α), vascular endothelial growth factor receptor 2 (VEGFR2) as hub targets of AS in angiogenesis. The intersection targets were enriched by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, and the hub targets were verified by immunofluorescence and western blot. Molecular docking of active components with hub targets was performed and verified in vitro. The results showed that AS extract promoted angiogenesis in preovulatory follicles and increased granulosa cell layer thickness, CD31 expression and content of VEGFA. Experiments in vitro and in vivo demonstrated that AS extract promoted the expression of HIF1α and VEGFA, up-regulated the phosphorylation levels of VEGFR2. These results further demonstrated the reliability of molecular docking and network pharmacology findings. In summary, AS extract can promote angiogenesis in the preovulatory follicles in late-phase laying hens.

Regulation of wheat bran feruloyl oligosaccharides in the intestinal antioxidative capacity of rats associated with the p38/JNK-Nrf2 signaling pathway and gut microbiota

BACKGROUND

Feruloyl oligosaccharides (FOs), the ferulic acid ester of oligosaccharides, may possess the physiological functions of both ferulic acid and oligosaccharides, including antioxidative activity and gut microbiota modulation capacity. The present study aimed to investigate whether FOs could regulate the intestinal antioxidative capacity of rats by modulating the MAPKs/Nrf2 signaling pathway and gut microbiota. Thirty Wistar rats were randomly divided into five groups. Rats received a standard diet and were gavaged once daily with 0.85% normal saline, 100 mg kg^-1 body weight vitamin C or FOs solution at doses of 20, 40 and 80 mg kg^-1 body weight for 21 days.

RESULTS

FOs strengthened the antioxidative capacity of the jejunum, as indicated by increased in contents of catalase, superoxide dismutase and glutathione peroxidase, as well as glutathione. Moreover, FOs administration upregulated the mRNA expression level of antioxidant-related genes (glutamate-cysteine ligase catalytic subunit, glutamate-cysteine ligase modifier subunit and heme oxygenase-1) in the jejunum. Increases in phosphorylation levels of Nrf2, p38 and JNK were also observed. Administration with 40 mg kg^-1 FOs altered the structure and composition of the cecal microbiota, which was indicated by the increased the relative abundances of Actinobacteria, Proteobacteria and Acidobacteriota, and the decreased the relative abundances of Firmicutes, Lachnospiraceae_NK4A136_group and Blautia. Furthermore, Spearman correlation analysis revealed that the altered cecal microbiota closely correlated with jejunal antioxidative capacity of rats.

CONCLUSION

FOs could be used as an antioxidant for gut heath improvement through modulating the p38/JNK-Nrf2 signaling pathway and gut microbiota. © 2022 Society of Chemical Industry.

Recent Advances in the Neuroprotective Properties of Ferulic Acid in Alzheimer's Disease: A Narrative Review

Alzheimer's disease (AD) is a progressive degenerative disorder of the central nervous system, characterized by neuroinflammation, neurotransmitter deficits, and neurodegeneration, which finally leads to neuronal death. Emerging evidence highlighted that hyperglycemia and brain insulin resistance represent risk factors for AD development, thus suggesting the existence of an additional AD form, associated with glucose metabolism impairment, named type 3 diabetes. Owing to the limited pharmacological options, novel strategies, especially dietary approaches based on the consumption of polyphenols, have been addressed to prevent or, at least, slow down AD progression. Among polyphenols, ferulic acid is a hydroxycinnamic acid derivative, widely distributed in nature, especially in cereal bran and fruits, and known to be endowed with many bioactivities, especially antioxidant, anti-inflammatory and antidiabetic, thus suggesting it could be exploited as a possible novel neuroprotective strategy. Considering the importance of ferulic acid as a bioactive molecule and its widespread distribution in foods and medicinal plants, the aim of the present narrative review is to provide an overview on the existing preclinical and clinical evidence about the neuroprotective properties and mechanisms of action of ferulic acid, also focusing on its ability to modulate glucose homeostasis, in order to support a further therapeutic interest for AD and type 3 diabetes.

Ferulic Acid Protects Human Lens Epithelial Cells against Ionizing Radiation-Induced Oxidative Damage by Activating Nrf2/HO-1 Signal Pathway

Ionizing radiation- (IR-) induced oxidative stress has been recognized as an important mediator of apoptosis in lens epithelial cells (LECs) and also plays an important role in the pathogenesis of IR-induced cataract. Ferulic acid (FA), a phenolic phytochemical found in many traditional Chinese medicine, has potent radioprotective and antioxidative properties via activating nuclear factor erythroid 2-related factor 2 (Nrf2) signal pathway. The goals of this study were to determine the protective effect of FA against IR-induced oxidative damage on human lens epithelial cells (HLECs) and to elucidate the role of Nrf2 signal pathway. HLECs were subjected to 4 Gy X-ray radiation with or without pretreatment of FA. It was found that FA pretreatment protected HLECs against IR-induced cell apoptosis and reduced levels of ROS and MDA caused by radiation in a dose-dependent manner. IR-dependent attenuated activities of antioxidant enzymes (SOD, CAT, and GPx) and decreased ratio of reduced GSH/GSSG were increased by pretreatment of FA. FA inhibited IR-induced increase of Bax and cleaved caspase-3 and the decrease of Bcl-2 in a dose-dependent manner. Furthermore, FA provoked Nrf2 nuclear translocation and upregulated mRNA and protein expressions of HO-1 in a dose-dependent manner. These findings indicated that FA could effectively protect HLECs against IR-induced apoptosis by activating Nrf2 signal pathway to inhibit oxidative stress, which suggested that FA might have a therapeutic potential in the prevention and alleviation of IR-induced cataract.

Effects and Mechanisms of Taohong Siwu Decoction on the Prevention and Treatment of Myocardial Injury

Taohong Siwu decoction (THSWD) is one of the classic prescriptions for promoting blood circulation and removing blood stasis. With the continuous in-depth excavation in basic and clinical research, it has been found that THSWD has made greater progress in the prevention and treatment of cardiovascular diseases. Mechanisms of the current studies have shown that it could prevent and treat the myocardial injury by inhibiting inflammatory reaction, antioxidant stress, inhibiting platelet aggregation, prolonging clotting time, anti-fibrosis, reducing blood lipids, anti-atherosclerosis, improving hemorheology and vascular pathological changes, regulating related signal pathways and other mechanisms to prevent and treat the myocardial injury, so as to protect cardiomyocytes and improve cardiac function. Many clinical studies have shown that THSWD is effective in the prevention and treatment of cardiovascular diseases related to myocardial injuries, such as coronary heart disease angina pectoris (CHD-AP), and myocardial infarction. In clinical practice, it is often used by adding and subtracting prescriptions, the combination of compound prescriptions and combinations of chemicals and so on. However, there are some limitations and uncertainties in both basic and clinical research of prescriptions. According to the current research, although the molecular biological mechanism of various active ingredients needs to be further clarified, and the composition and dose of the drug have not been standardized and quantified, this study still has exploration for scientific research and clinical practice. Therefore, this review mainly discusses the basic mechanisms and clinical applications of THSWD in the prevention and treatment of the myocardial injury caused by CHD-AP and myocardial infarction. The authors hope to provide valuable ideas and references for researchers and clinicians.

Activation of Nrf2/HO-1 signaling: An important molecular mechanism of herbal medicine in the treatment of atherosclerosis via the protection of vascular endothelial cells from oxidative stress

Introduction

Recently, Nrf2/HO-1 has received extensive attention as the main regulatory pathway of intracellular defense against oxidative stress and is considered an ideal target for alleviating endothelial cell (EC) injury.

Objectives

This paper aimed to summarized the natural monomers/extracts that potentially exert protective effects against oxidative stress in ECs.

Methods

A literature search was carried out regarding our topic with the keywords of “atherosclerosis” or “Nrf2/HO-1” or “vascular endothelial cells” or “oxidative stress” or “Herbal medicine” or “natural products” or “natural extracts” or “natural compounds” or “traditional Chinese medicines” based on classic books of herbal medicine and scientific databases including Pubmed, SciFinder, Scopus, the Web of Science, GoogleScholar, BaiduScholar, and others. Then, we analyzed the possible molecular mechanisms for different types of natural compounds in the treatment of atherosclerosis via the protection of vascular endothelial cells from oxidative stress. In addition, perspectives for possible future studies are discussed.

Results

These agents with protective effects against oxidative stress in ECs mainly include phenylpropanoids, flavonoids, terpenoids, and alkaloids. Most of these agents alleviate cell apoptosis in ECs due to oxidative stress, and the mechanisms are related to Nrf2/HO-1 signaling activation. However, despite continued progress in research on various aspects of natural agents exerting protective effects against EC injury by activating Nrf2/HO-1 signaling, the development of new drugs for the treatment of atherosclerosis (AS) and other CVDs based on these agents will require more detailed preclinical and clinical studies.

Conclusion

Our present paper provides updated information of natural agents with protective activities on ECs against oxidative stress by activating Nrf2/HO-1. We hope this review will provide some directions for the further development of novel candidate drugs from natural agents for the treatment of AS and other CVDs.

Ferulic acid: A review of its pharmacology, pharmacokinetics and derivatives

Ferulic acid, a kind of phenolic substance widely existing in plants, is an important active component of many traditional Chinese medicines. So far, it has been proved that ferulic acid has a variety of biological activities, especially in oxidative stress, inflammation, vascular endothelial injury, fibrosis, apoptosis and platelet aggregation. Many studies have shown that ferulic acid can inhibit PI3K/AKT pathway, the production of ROS and the activity of aldose reductase. The anti-inflammatory effect of ferulic acid is mainly related to the levels of PPAR γ, CAM and NF-κ B and p38 MAPK signaling pathways. Ferulic acid not only protects vascular endothelium by ERK1/2 and NO/ET-1 signal, but also plays an anti-fibrosis role by TGF-β/Smad and MMPs/TIMPs system. Moreover, ferulic acid has ant-apoptotic and anti-platelet effects. In addition to the pharmacological effects of ferulic acid, its pharmacokinetics and derivatives were also discussed in this paper. This review provides the latest summary of the latest research on ferulic acid.

An Overview on Dietary Polyphenols and Their Biopharmaceutical Classification System (BCS)

Polyphenols are natural organic compounds produced by plants, acting as antioxidants by reacting with ROS. These compounds are widely consumed in daily diet and many studies report several benefits to human health thanks to their bioavailability in humans. However, the digestion process of phenolic compounds is still not completely clear. Moreover, bioavailability is dependent on the metabolic phase of these compounds. The LogP value can be managed as a simplified measure of the lipophilicity of a substance ingested within the human body, which affects resultant absorption. The biopharmaceutical classification system (BCS), a method used to classify drugs intended for gastrointestinal absorption, correlates the solubility and permeability of the drug with both the rate and extent of oral absorption. BCS may be helpful to measure the bioactive constituents of foods, such as polyphenols, in order to understand their nutraceutical potential. There are many literature studies that focus on permeability, absorption, and bioavailability of polyphenols and their resultant metabolic byproducts, but there is still confusion about their respective LogP values and BCS classification. This review will provide an overview of the information regarding 10 dietarypolyphenols (ferulic acid, chlorogenic acid, rutin, quercetin, apigenin, cirsimaritin, daidzein, resveratrol, ellagic acid, and curcumin) and their association with the BCS classification.

Effects of diabetes on the development of radiation pneumonitis

Radiation pneumonia (RP) is a common adverse reaction to radiation therapy in patients with chest tumors. Recent studies have shown that diabetes mellitus (DM), which can cause systemic multisystem damage, specifically targets lungs, and the incidence of RP in patients with a history of diabetes is higher than that in other patients with tumors who have undergone radiotherapy. DM is an important risk factor for RP in tumor patients undergoing RT, and patients with DM should be treated with caution. This article reviews research on the clinical aspects, as well as the mechanism, of the effects of diabetes on RP and suggests future research needed to reduce RP.

A Review on Potential Footprints of Ferulic Acid for Treatment of Neurological Disorders

Ferulic acid is being screened in preclinical settings to combat various neurological disorders. It is a naturally occurring dietary flavonoid commonly found in grains, fruits, and vegetables such as rice, wheat, oats, tomatoes, sweet corn etc., which exhibits protective effects against a number of neurological diseases such as epilepsy, depression, ischemia-reperfusion injury, Alzheimer's disease, and Parkinson's disease. Ferulic acid prevents and treats different neurological diseases pertaining to its potent anti-oxidative and anti-inflammatory effects, beside modulating unique neuro-signaling pathways. It stays in the bloodstream for longer periods than other dietary polyphenols and antioxidants and easily crosses blood brain barrier. The use of novel drug delivery systems such as solid-lipid nanoparticles (SLNs) or its salt forms (sodium ferulate, ethyl ferulate, and isopentyl ferulate) further enhance its bioavailability and cerebral penetration. Based on reported studies, ferulic acid appears to be a promising molecule for treatment of neurological disorders; however, more preclinical (in vitro and in vivo) mechanism-based studies should be planned and conceived followed by its testing in clinical settings.

Mitigative efficacy of the clinical dosage administration of granulocyte colony-stimulating factor and romiplostim in mice with severe acute radiation syndrome

BACKGROUND

It has been reported that the high-dosage administration of domestically approved pharmaceutical drugs, especially granulocyte colony-stimulating factor (G-CSF) and romiplostim (RP), is a rapid and appropriate medical treatment for preventing severe acute radiation syndrome (ARS) of victims exposed to lethal total-body irradiation (TBI). However, it remains unclear whether or not the clinical dosage administration of these drugs can ameliorate TBI-induced ARS and related high mortality in order to find various drug treatment options and less toxic optimum protocol depending on the situation surrounding the radiological accidents.

METHODS

We assessed the clinical dosage administration in combination with G-CSF and RP as intraperitoneal injection in C57BL/6 J mice exposed to more than 7-Gy lethal dose of X-ray TBI for the survival study evaluated by the log-rank test. Bone marrow and splenic cells were collected on the 21st day, when 1 week has passed from last administration, to detect the level of cell apoptosis, intracellular reactive oxygen species (ROS), and nuclear factor erythroid 2-related factor 2 (Nrf2)-related anti-oxidative gene expressions, and enzyme-linked immune sorbent assay using sera was performed for cell senescence and inflammation status analyzed with one-way ANOVA and Tukey-Kramer or Bonferroni/Dunn multiple comparison tests.

RESULTS

The combined once-daily administration of 10 μg/kg G-CSF for 4 times and 10 μg/kg RP once a week for 3 times improve the 30-day survival rate of lethal TBI mice compared with untreated TBI mice, accompanied by a gradual increase in the body weight and hematopoietic cell numbers. The radio-mitigative effect is probably attributed to the scavenging of ROS and the reduction in cell apoptosis. These changes were associated with the upregulation of Nrf2 and its downstream anti-oxidative targets in TBI mice. Furthermore, this combination modulated TBI-induced cell senescence an d inflammation markers.

CONCLUSIONS

This study suggested that the clinical dosage administration in combination with G-CSF and RP may also have radio-mitigative effects on mice exposed to lethal TBI and may be a potent therapeutic agent for mitigating radiation-induced severe ARS.

Counteracting role of nuclear factor erythroid 2-related factor 2 pathway in Alzheimer's disease

A salient pathological features in Alzheimer's disease includes redox impairment and neuroinflammation. Nuclear factor erythroid 2-related factor 2 (Nrf2) and Nuclear factor kappa B (NF-ҡB) are the two key transcription factors that regulate cellular responses to redox impairment and neuroinflammation respectively. An effective way to confer neuroprotection in central nervous system (CNS) is the activation of a transcription factor i.e Nuclear factor erythroid 2-related factor 2 (Nrf2). An enhancer element known as Antioxidant Response Element (ARE) mediates the expression of phase II detoxification enzymes. Nrf2 is a nuclear transcription factor that binds to ARE thereby transcribing expression of several antioxidant genes. Kelch ECH associating protein-1 (Keap1), a culin 3-based E3 ligase, polyubiquitinates Nrf2 and targets it for its degradation. Disruption in the interaction between Keap1/Nrf2 can increase the brain's endogenous antioxidant capacity and thereby responsible for cell defence against oxidative stress and neuroinflammation in Alzheimer's disease (AD). The current review discusses about Keap1-Nrf2-ARE structure and function with special emphasis on the various pathways involved in positive and negative modulation of Nrf2, namely Phosphoinositide 3- kinase (PI3K), Glycogen synthase kinase-3β (GSK-3β), Nuclear factor kappa-b (NF-ҡb), Janus kinase/signal transducer and activator of transcription (JAK-STAT),Tumour Necrosis Factor- α (TNF-α), p38Mitogen-activated protein kinases (p38MAPK), Cyclic AMP response element binding protein (CREB) and intrinsic & extrinsic apoptotic pathway. Furthermore, this review highlights the miscellaneous Nrf2 activators as promising therapeutic agents for slowingdown the progression of AD.

The Effects of Dietary Supplements that Overactivate the Nrf2/ARE System

Background:

Inflammation is one of the most misunderstood aspects of human health. People have been encouraged to eat foods that have a high antioxidant capacity, and in vitro tests for total antioxidant capacity emerged. They were based on measuring the destruction of oxidized test compounds in direct reactions with the antioxidants in foods. Many dietary supplements arrived in the market. They contained purified antioxidants, such as resveratrol and EGCG that were and still are widely assumed by many to be quite healthy at any dose.

Methods:

The literature on inflammation and the Nrf2/ARE antioxidant system was searched systematically. Articles from prestigious, peer-reviewed journals were obtained and read. The information obtained from them was used to write this review article.

Results:

Over 150 articles and books were read. The information obtained from them showed that very few dietary antioxidants exert their effects by reacting directly with Reactive Oxygen and Nitrogen Species (RONS). Instead, most of the effective antioxidants activate the endogenous Nrf2/ARE antioxidant system. This helps prevent smoldering inflammation and the diseases that it can cause. However, when overactivated or activated constitutively, the Nrf2/ARE antioxidant system can cause some of these diseases, including many types of multidrug resistant cancer, autoimmune, neurodegenerative and cardiovascular diseases.

Conclusion:

Even though green tea, as well as many fruits, vegetables and spices are quite healthy, dietary supplements that deliver much higher doses of antioxidants may not be. People who are diagnosed with cancer and plan to start chemotherapy and/or radiotherapy should probably avoid such supplements. This is because multidrug resistant tumors can hijack and overactivate the Nrf2/ARE antioxidant system.

Ferulic Acid Ameliorates Lipopolysaccharide-Induced Barrier Dysfunction via MicroRNA-200c-3p-Mediated Activation of PI3K/AKT Pathway in Caco-2 Cells

Intestinal barrier dysfunction is an important clinical problem in various acute and chronic pathological conditions. Ferulic acid (FA) can attenuate the intestinal epithelial barrier dysfunction, however, the underlying mechanism remains unclear. The present study aimed to uncover the protective effect of FA on intestinal epithelial barrier dysfunction in a Caco-2 cell model of lipopolysaccharide (LPS) stimulation and the underlying mechanism. Caco-2 cells were pretreated with FA and then exposed to LPS stimulation. The barrier function of Caco-2 cells was evaluated by measuring trans-epithelial resistance (TER) and 4-kDa fluorescein isothiocyanate (FITC)-dextran (FD4) flux, and analyzing the tight junction protein expression and structure. The results showed that decreased TER and increased FITC-FD4 flux were observed in Caco-2 cells stimulated with LPS, but these effects were attenuated by FA pretreatment. FA pretreatment inhibited LPS-induced decrease in occludin and ZO-1 mRNA and protein expression. LPS stimulation decreased miR-200c-3p expression, whereas this decrease was inhibited by FA pretreatment. Furthermore, overexpression of miR-200c-3p strengthened the protective effects of FA on LPS-induced Caco-2 cell barrier dysfunction by decreasing epithelial permeability, increasing occludin and ZO-1 protein expression, and maintaining of ZO-1 protein distribution, while suppression of miR-200c-3p reversed the protective effects of FA. LPS treatment increased the expression of PTEN protein and decreased expression of phosphorylated PI3K and AKT proteins. However, pretreatment of FA inhibited expression of PTEN protein and promoted activation of PI3K/AKT signaling pathway in the LPS-treated Caco-2 cells, and this regulatory effect of FA on the PTEN/PI3K/AKT signaling pathway was strengthened or weakened by miR-200c-3p overexpression or suppression, respectively. Our findings suggested that in Caco-2 cells, FA promotes activation of PI3K/AKT pathway by miR-200c-3p-mediated suppression of the negative mediator PTEN, which, in turn, maintains TJ function and thus ameliorates LPS-induced intestinal epithelial barrier dysfunction.

The genus Tragopogon (Asteraceae): A review of its traditional uses, phytochemistry, and pharmacological properties

ETHNOPHARMACOLOGICAL RELEVANCE

Species of Tragopogon are used in traditional medicine, and consumed as vegetables across the world. In terms of the medicinal uses of Tragopogon, different species have found use in traditional medicine, including uses for wound-healing, treatment of gastrointestinal and hepatic complaints, cancer, kidney and liver dysfunction, inflamed skin and certain cutaneous diseases, as well as constipation, fatigue and anoxia.

AIM OF THE STUDY

The aim of this review is to highlight and critically summarize those species of the genus that have been studied as a source of interesting lead compounds, and their traditional uses and bioactivities.

MATERIALS AND METHODS

A comprehensive and systematic review of literature on traditional uses, phytochemicals and pharmacological properties of the genus Tragopogon was carried out. Information was retrieved from secondary databases such as Scopus, Chemical Abstracts Services (Scifinder), Pubmed, Google Scholar and ScienceDirect, in addition to primary sources including books, PhD and MSc dissertations, and official websites. Species names were validated using "The Plant List" (www.theplantlist.org).

RESULTS

The taxa of the genus Tragopogon are known for their local and traditional uses as medicine for treatment of various diseases, and have been consumed as vegetables and snacks for generations in Eurasia, the Mediterranean, Caucasus, Europe and North America. From the approximately 110 species of Tragopogon, only twelve species have been scientifically evaluated for their bioactivity and/or phytochemical composition. Tragopogon species are a rich source of phytochemical constituents and among those that have been identified are 19 flavonoids, 35 terpenoids, seven bibenzyl derivatives, five benzylphtalides, six stilbenes, nine dihydroisocoumarin derivatives, nine phenylmethane derivatives, three hydroxyphenylacetic acid derivatives, four phenylpropane derivatives, four esters of phenylpropanoic acids, a coumarin derivative, and a spermine derivative. Various extracts of the taxa, in addition to the isolated compounds, demonstrated pharmacological properties such as antitumor, antimicrobial, anti-inflammatory and enzyme inhibitory activities, in addition to hepatoprotective, antihyperlipidaemic and wound-healing properties.

CONCLUSION

This review highlights the traditional uses, phytochemistry and pharmacological properties of the few studied taxa of the genus Tragopogon. Some of the reviewed papers were not of an appropriate methodological standard. For instance, phytochemical profiles were not determined, and the fundamental requirements of the pharmacological properties were not defined such as including appropriate positive and negative controls, and calculating the MIC values. Furthermore, these studies did not provide an in depth evaluation of bioactivity of the extracts and the isolated compounds or in vivo experiments which could indicate therapeutic relevance. From a phytopharmacological point of view, this review recommends more high quality evidence-based research on Tragopogon species for further development of plant-derived remedies and compounds.

Impact of Antioxidant Natural Compounds on the Thyroid Gland and Implication of the Keap1/Nrf2 Signaling Pathway

BACKGROUND

Natural compounds with potential antioxidant properties have been used in the form of food supplements or extracts with the intent to prevent or treat various diseases. Many of these compounds can activate the cytoprotective Nrf2 pathway. Besides, some of them are known to impact the thyroid gland, often with potential side-effects, but in other instances, with potential utility in the treatment of thyroid disorders.

OBJECTIVE

In view of recent data regarding the multiple roles of Nrf2 in the thyroid, this review summarizes the current bibliography on natural compounds that can have an effect on thyroid gland physiology and pathophysiology, and it discusses the potential implication of the Nrf2 system in the respective mechanisms.

METHODS & RESULTS

Literature searches for articles from 1950 to 2018 were performed in PubMed and Google Scholar using relevant keywords about phytochemicals, Nrf2 and thyroid. Natural substances were categorized into phenolic compounds, sulfur-containing compounds, quinones, terpenoids, or under the general category of plant extracts. For individual compounds in each category, respective data were summarized, as derived from in vitro (cell lines), preclinical (animal models) and clinical studies. The main emerging themes were as follows: phenolic compounds often showed potential to affect the production of thyroid hormones; sulfur-containing compounds impacted the pathogenesis of goiter and the proliferation of thyroid cancer cells; while quinones and terpenoids modified Nrf2 signaling in thyroid cell lines.

CONCLUSION

Natural compounds that modify the activity of the Nrf2 pathway should be evaluated carefully, not only for their potential to be used as therapeutic agents for thyroid disorders, but also for their thyroidal safety when used for the prevention and treatment of non-thyroidal diseases.

The Heme Oxygenase/Biliverdin Reductase System as Effector of the Neuroprotective Outcomes of Herb-Based Nutritional Supplements

Over the last few years, several preclinical studies have shown that some herbal products, such as ferulic acid, Ginkgo biloba, and resveratrol, exert neuroprotective effects through the modulation of the heme oxygenase/biliverdin reductase system. Unfortunately, sufficient data supporting the shift of knowledge from preclinical studies to humans, particularly in neurodegenerative diseases, are not yet available in the literature. The purpose of this review is to summarize the studies and the main results achieved on the potential therapeutic role of the interaction between the heme oxygenase/biliverdin reductase system with ferulic acid, G. biloba, and resveratrol. Some critical issues have also been reported, mainly concerning the safety profile and the toxicological sequelae associated to the supplementation with the herbs mentioned above, based on both current literature and specific reports issued by the competent Regulatory Authorities.

Reasonably activating Nrf2: A long-term, effective and controllable strategy for neurodegenerative diseases

Neurodegenerative diseases are a variety of debilitating and fatal disorder in central nervous system (CNS). Besides targeting neuronal activity by influencing neurotransmitters or their corresponding receptors, modulating the underlying processes that lead to cell death, such as oxidative stress and mitochondrial dysfunction, should also be emphasized as an assistant strategy for neurodegeneration therapy. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) has been closely verified to be related to anti-inflammation and oxidative stress, rationally regulating its belonging pathway and activating Nrf2 is emphasized to be a potential treatment approach. There have existed multiple Nrf2 activators with different mechanisms and diverse structures, but those applied for neuro-disorders are still limited. On the basis of research arrangement and compound summary, we put forward the limitations of existing Nrf2 activators for neurodegenerative diseases and their future developing directions in enhancing the blood-brain barrier permeability to make Nrf2 activators function in CNS and designing Nrf2-based multi-target-directed ligands to affect multiple nodes in pathology of neurodegenerative diseases.

Dietary Anthocyanins and Stroke: A Review of Pharmacokinetic and Pharmacodynamic Studies

Cerebrovascular accidents are currently the second major cause of death and the third leading cause of disability in the world, according to the World Health Organization (WHO), which has provided protocols for stroke prevention. Although there is a multitude of studies on the health benefits associated with anthocyanin (ACN) consumption, there is no a rigorous systematization of the data linking dietary ACN with stroke prevention. This review is intended to present data from epidemiological, in vitro, in vivo, and clinical studies dealing with the stroke related to ACN-rich diets or ACN supplements, along with possible mechanisms of action revealed by pharmacokinetic studies, including ACN passage through the blood-brain barrier (BBB).

Anthocyanins: From Sources and Bioavailability to Cardiovascular-Health Benefits and Molecular Mechanisms of Action

Anthocyanins are phytochemicals widely found in plant foods, with berries and fruit-derived beverages as the main dietary sources. Accumulating evidence suggests the positive role of anthocyanins in preserving cardiovascular health. Epidemiological data show an association between anthocyanin intake and lower risk of myocardial infarction and cardiovascular-disease-related mortality. Clinical studies report the beneficial effects of the consumption of different anthocyanin-rich sources on surrogate markers of cardiovascular risk. Animal and in vitro evidence suggest the protective role of anthocyanins in dysfunctions related to the development of cardiovascular diseases. Still, the underlying molecular mechanisms of anthocyanin action seem complex and are not entirely clear. This review aims to give a comprehensive update on anthocyanins and their cardioprotective properties. It provides information on their sources; quantities consumed through diet; absorption; bioavailability; cardiovascular properties; and underlying mechanisms of action, including their effects on gene and protein expression and their interactions with cell-signaling pathways and miRNAs.

Analysis of Popcorn (Zea mays L. var. everta) for Antioxidant Capacity and Total Phenolic Content

Popcorn, one of the most popular snack foods in the world, is known for being a high fiber, healthy food. Our research has found that commercial popcorn also contains significant amounts of the class of antioxidants known as phenolic acids. The total antioxidant power of raw and popped popcorn extract has been quantified using the Folin-Ciocalteu and FRAP assays. The polyphenols were found exclusively in the pericarp of the kernel completely bound to the oligosaccharide fiber matrix. An in vitro digestion study was also performed to predict the phenolic acids' bioavailability. On average, nine commercial popcorn samples contain 5.93 ± 0.92 mg/g of total polyphenols after alkaline hydrolysis and 2.66 ± 0.15 mg/g after in vitro digestion as measured by the Folin-Ciocalteu assay. Furthermore, the popping process was found not to significantly decrease the antioxidant capacity. These results indicate that a considerable amount of the bound polyphenols are bioaccessible. Due to the high levels of bioaccessible polyphenols, popcorn may be a significant source of dietary polyphenol antioxidants.

Islet Transplantation Attenuating Testicular Injury in Type 1 Diabetic Rats Is Associated with Suppression of Oxidative Stress and Inflammation via Nrf-2/HO-1 and NF-κB Pathways

Testicular structural and functional impairment is a serious complication in male diabetes mellitus (DM) patients that leads to impaired fertility in adulthood. In contrast to other endocrine therapies, islet transplantation (IT) can effectively prevent and even reverse diabetic nephropathy and myocardial damage. However, whether IT can alleviate diabetes-induced testicular injury remains unclear. In this study, we sought to investigate the effect of IT on diabetes-induced testicular damage. A diabetic rat model was established by streptozotocin injection. DM, IT, and insulin treatment (INS) groups were compared after 4 weeks of respective treatment. We confirmed that IT could effectively attenuate diabetes-induced testicular damage and recover sperm counts more extensively compared with INS in diabetic rats. In addition, significantly higher levels of superoxide dismutase (SOD) activity and lower contents of malondialdehyde (MDA) were detected in the testes of the IT group versus diabetic rats. Mechanism studies revealed that IT significantly activates the expression of Nrf-2, HO-1, and NQO-1 and inhibits upregulation of the NF-κB expression in response to DM, while INS only exhibit slight impact on the protein expression. Therefore, we speculate that IT may prevent the progression of testicular damage by downregulating oxidative stress and inhibiting inflammation via Nrf-2/HO-1 and NF-κB pathways.

Effects of dietary ramie powder at various levels on growth performance, antioxidative capacity and fatty acid profile of finishing pigs

This study was conducted to evaluate the effects of ramie (Boehmeria nivea, previously known as a fibre crop and also called "China grass") included in diets on growth performance, antioxidative capacity and muscular fatty acid profile of finishing pigs. A total of 180 Xiangcun Black pigs (initial body weight =70.71 ± 1.21 kg) were randomly allotted to 1 of 5 dietary treatments with six pens of six pigs per pen. The pigs were provided a basal diet or a diet contained 3%, 6%, 9% or 12% of ramie powder during a 50-day experiment period. The results showed that the inclusion of ramie increased (quadratic, p < 0.05) the average daily gain (ADG) and gain:feed ratio (G:F) with the highest value of ADG and G:F in 3% ramie group, but ramie content in the diet up to 9% reduced the growth performance of the pigs compared with that of 3% ramie group. The activity of serum total superoxide dismutase (SOD) was increased (linear, p < 0.05) by ramie, while content of malondialdehyde was decreased (linear, p < 0.05). As increasing the dietary ramie level, the mRNA expression level of SOD1 was increased quadratically (p < 0.05) in muscle tissues. Moreover, the addition of ramie linearly increased (p < 0.05) polyunsaturated fatty acids content, whereas it linearly reduced (p < 0.05) the lipid indices of atherogenicity (AI) and thrombogenicity (TI) in muscle tissues, and lower values of AI and TI reflect a "healthier" fat composition. The results indicated that ramie in a diet not more than 9% may improve antioxidative capacity with no detrimental impact on growth performance of Chinese native finishing pigs; meanwhile, it could beneficially change the pork fatty acid pattern which has a positive impact on consumer's health.

Effects of CeO2 nanoparticles on the HO-1, NQO1, and GCLC expression in the testes of diabetic rats

CeO₂ nanoparticles (CNPs) as effective ROS scavengers exhibit potent antioxidant activity. In this study the effect of CNPs investigated was on HO-1, NQO1, and GCLC expression in the streptozotocin (STZ)-induced diabetic rats. Twenty-four male Wistar rats were divided into 4 groups: controls did not receive any treatment; diabetic rats received STZ (60 mg/kg daily); CNPs group received CNPs 30 mg/kg daily for 2 weeks; and rats in STZ + CNPs group received CNPs 30 mg/kg daily for 2 weeks following STZ injection. Oxidative stress was evaluated by measurement of total antioxidant capacity (TAC) and total oxidative status (TOS levels). HO-1, NQO1, and GCLC expression was measured using quantitative real-time PCR. Following STZ injection, significant lower levels of TAC and higher levels of TOS were observed. CNPs could alleviate deleterious effects of diabetes through the enhancement of TAC levels and a significant decline in TOS levels. HO-1, NQO1, and GCLC expression in the diabetic rats were lower than controls. HO-1, NQO1, and GCLC was upregulated in the diabetic rats treated with CNPs. There were significant correlations between NQO1 and GCLC, NQO1 and HO-1, and between HO-1 and GCLC expression. Moreover, Nrf2 was associated with NQO1, GCLC, and HO-1 expression. CNPs as Nrf2 upregulator confer protection against oxidative stress in the testes of STZ-induced diabetic rats by upregulating HO-1, GCLC, and NQO1 cytoprotective genes.

Bioavailable Blueberry-Derived Phenolic Acids at Physiological Concentrations Enhance Nrf2-Regulated Antioxidant Responses in Human Vascular Endothelial Cells

SCOPE

Blueberry consumption is believed to confer a cardiovascular health advantage, but the active compounds and effects require characterization. This study aims to identify the polyphenol metabolites in plasma after blueberry juice intake and determine their bioactivity on endothelial cells.

METHODS AND RESULTS

Three healthy individuals are recruited to obtain profiles of bioavailable plasma polyphenol metabolites following intake of blueberry juice. Of 33 phenolic compounds screened, 12 aglycone phenolic acids are detected and their maximum plasma concentrations and circulation time determined. Using this information, the effect of three physiologically relevant mixtures of blueberry-derived phenolic acids is investigated for their ability to induce nuclear factor erythroid 2-related factor 2 (Nrf2)-nuclear translocation and downstream gene expression in human endothelial cells. Pretreatment with the phenolic acids for 18 h results in a significant upregulation of the Nrf2-regulated antioxidant response proteins heme oxygenase 1 (HO-1) and glutamate-cysteine ligase modifier subunit (GCLM), following 6 h exposure to 2.5 μm H₂ O₂ .

CONCLUSION

Physiologically relevant concentrations of blueberry-derived aglycone phenolic acids can induce Nrf2-regulated antioxidant response proteins in vascular endothelial cells in response to low μm concentrations of H₂ O₂ . Our results represent an advance over previous studies that have used single compounds or high concentrations in cell-based investigations.

Pelargonidin Modulates Keap1/Nrf2 Pathway Gene Expression and Ameliorates Citrinin-Induced Oxidative Stress in HepG2 Cells

Pelargonidin chloride (PC) is one of the major anthocyanin found in berries, radish and other natural foods. Many natural chemopreventive compounds have been shown to be potent inducers of phase II detoxification genes and its up-regulation is important for oxidative stress related disorders. In the present study, we investigated the effect of PC in ameliorating citrinin (CTN) induced cytotoxicity and oxidative stress. The cytotoxicity of CTN was evaluated by treating HepG2 (Human hepatocellular carcinoma) cells with CTN (0–150 μM) in a dose dependent manner for 24 h, and the IC₅₀ was determined to be 96.16 μM. CTN increased lactate dehydrogenase leakage (59%), elevated reactive oxygen species (2.5-fold), depolarized mitochondrial membrane potential as confirmed by JC-1 monomers and arrested cell cycle at G2/M phase. Further, apoptotic and necrotic analysis revealed significant changes followed by DNA damage. To overcome these toxicological effects, PC was pretreated for 2 h followed by CTN exposure for 24 h. Pretreatment with PC resulted in significant increase in cell viability (84.5%), restored membrane integrity, reactive oxygen species level were maintained and cell cycle phases were normal. PC significantly up-regulated the activity of detoxification enzymes: heme oxygenase 1 (HO-1), glutathione transferase, glutathione peroxidase, superoxide dismutase and quinone reductase. Nrf2 translocation into the nucleus was also observed by immunocytochemistry analysis. These data demonstrate the protective effect of PC against CTN-induced oxidative stress in HepG2 cells and up-regulated the activity of detoxification enzyme levels through Keap1/Nrf2 signaling pathway.

Ferulic Acid Improves Cognitive Skills Through the Activation of the Heme Oxygenase System in the Rat

Over the last years, many studies reported on the antioxidant effects of ferulic acid (FA) in preclinical models of dementia through the activation of the heme oxygenase/biliverdin reductase (HO/BVR) system. However, only a few studies evaluated whether FA could improve neurological function under milder conditions, such as psychological stress. The aim of this study was to investigate the effects of FA (150 mg/kg intraperitoneal route) on cognitive function in male Wistar rats exposed to emotional arousal. Animals were randomly assigned to two experimental groups, namely not habituated or habituated to the experimental context, and the novel object recognition test was used to evaluate their cognitive performance. The administration of FA significantly increased long-term retention memory in not habituated rats. Ferulic acid increased the expression of HO-1 in the hippocampus and frontal cortex of not habituated rats only, whereas HO-2 resulted differently modulated in these cognitive brain areas. No significant effects on either HO-1 or HO-2 or BVR were observed in the cerebellum of both habituated and not habituated rats. Ferulic acid activated the stress axis in not habituated rats, as shown by the increase in hypothalamic corticotrophin-releasing hormone levels. Pre-treatment with Sn-protoporphyrin-IX [0.25 μmol/kg, intracerebroventricular route (i.c.v.)], a well-known inhibitor of HO activity through which carbon monoxide (CO) and biliverdin (BV) are generated, abolished the FA-induced improvement of cognitive performance only in not habituated rats, suggesting a role for HO-derived by-products. The CO-donor tricarbonyldichlororuthenium (II) (30 nmol/kg i.c.v.) mimicked the FA-related improvement of cognitive skills only in not habituated rats, whereas BV did not have any effect in any group. In conclusion, these results set the stage for subsequent studies on the neuropharmacological action of FA under conditions of psychological stress.

The Role of the Nrf2/ARE Antioxidant System in Preventing Cardiovascular Diseases

It is widely believed that consuming foods and beverages that have high concentrations of antioxidants can prevent cardiovascular diseases and many types of cancer. As a result, many articles have been published that give the total antioxidant capacities of foods in vitro. However, many antioxidants behave quite differently in vivo. Some of them, such as resveratrol (in red wine) and epigallocatechin gallate or EGCG (in green tea) can activate the nuclear erythroid-2 like factor-2 (Nrf2) transcription factor. It is a master regulator of endogenous cellular defense mechanisms. Nrf2 controls the expression of many antioxidant and detoxification genes, by binding to antioxidant response elements (AREs) that are commonly found in the promoter region of antioxidant (and other) genes, and that control expression of those genes. The mechanisms by which Nrf2 relieves oxidative stress and limits cardiac injury as well as the progression to heart failure are described. Also, the ability of statins to induce Nrf2 in the heart, brain, lung, and liver is mentioned. However, there is a negative side of Nrf2. When over-activated, it can cause (not prevent) cardiovascular diseases and multi-drug resistance cancer.

The Chemistry of Gut Microbial Metabolism of Polyphenols

Gut microbiota contribute to the metabolism of dietary polyphenols and affect the bioavailability of both the parent polyphenols and their metabolites. Although there is a large number of reports of specific polyphenol metabolites, relatively little is known regarding the chemistry and enzymology of the metabolic pathways utilized by specific microbial species and taxa, which is the focus of this review. Major classes of dietary polyphenols include monomeric and oligomeric catechins (proanthocyanidins), flavonols, flavanones, ellagitannins, and isoflavones. Gut microbial metabolism of representatives of these polyphenol classes can be classified as A- and C-ring cleavage (retro Claisen reactions), C-ring cleavage mediated by dioxygenases, dehydroxylations (decarboxylation or reduction reactions followed by release of H₂O molecules), and hydrogenations of alkene moieties in polyphenols, such as resveratrol, curcumin, and isoflavones (mediated by NADPH-dependent reductases). The qualitative and quantitative metabolic output of the gut microbiota depends to a large extent on the metabolic capacity of individual taxa, which emphasizes the need for assessment of functional analysis in conjunction with determinations of gut microbiota compositions.

Ferulic Acid Regulates the Nrf2/Heme Oxygenase-1 System and Counteracts Trimethyltin-Induced Neuronal Damage in the Human Neuroblastoma Cell Line SH-SY5Y

Over the past years, several lines of evidence have pointed out the efficacy of ferulic acid (FA) in counteracting oxidative stress elicited by β-amyloid or free radical initiators, based on the ability of this natural antioxidant to up-regulate the heme oxygenase-1 (HO-1) and biliverdin reductase (BVR) system. However, scarce results can be found in literature regarding the cytoprotective effects of FA in case of damage caused by neurotoxicants. The aim of this work is to investigate the mechanisms through which FA exerts neuroprotection in SH-SY5Y neuroblastoma cells exposed to the neurotoxin trimethyltin (TMT). FA (1-10 μM for 6 h) dose-dependently increased both basal and TMT (10 μM for 24 h)-induced HO-1 expression in SH-SY5Y cells by fostering the nuclear translocation of the transcriptional activator Nrf2. In particular, the co-treatment of FA (10 μM) with TMT was also responsible for the nuclear translocation of HO-1 in an attempt to further increase cell stress response in SH-SY5Y cells. In addition to HO-1, FA (1-10 μM for 6 h) dose-dependently increased the basal expression of BVR. The antioxidant and neuroprotective features of FA, through the increase of HO activity, were supported by the evidence that FA inhibited TMT (10 μM)-induced lipid peroxidation (evaluated by detecting 4-hydroxy-nonenal) and DNA fragmentation in SH-SY5Y cells and that this antioxidant effect was reversed by the HO inhibitor Zinc-protoporphyrin-IX (5 μM). Among the by-products of the HO/BVR system, carbon monoxide (CORM-2, 50 nM) and bilirubin (BR, 50 nM) significantly inhibited TMT-induced superoxide anion formation in SH-SY5Y cells. All together, these results corroborate the neuroprotective effect of FA through the up-regulation of the HO-1/BVR system, via carbon monoxide and BR formation, and provide the first evidence on the role of HO-1/Nrf2 axis in FA-related enhancement of cell stress response in human neurons.

Curcumin upregulates Nrf2 nuclear translocation and protects rat hepatic stellate cells against oxidative stress

The present study aimed to investigate the protective role of curcumin against oxidative stress in rat hepatic stellate cells (HSCs)-T6, and to determine the possible underlying mechanisms. HSC-T6 cells were divided into three groups: Negative control group, oxidant-treated group and curcumin-treated group. Flow cytometry and spectrophotometry were used to measure the production of reactive oxygen species (ROS), and the levels of malondialdehyde (MDA) and glutathione (GSH). Immunocytochemistry and a radioimmunoassay were used to determine the expression of smooth muscle α-actin (α-SMA) and the secretion of extracellular matrix (ECM) molecules. In addition, western blotting and immunocytochemistry were used to determine the expression levels of nuclear factor-erythroid 2-related factor (Nrf2). Treatment with glucose oxidase (GO) significantly stimulated the formation of ROS and increased the production of MDA, as compared with the control cells; however, the production of GSH was only slightly increased. In addition, treatment with GO significantly promoted the expression of α-SMA and the secretion of ECM molecules. Conversely, treatment with curcumin significantly decreased the levels of ROS and MDA, and significantly increased the levels of GSH. Curcumin significantly inhibited the expression of α-SMA and decreased the secretion of ECM molecules. Furthermore, treatment with curcumin significantly increased the nuclear expression levels of Nrf2. These results indicated that curcumin may protect rat HSCs against oxidative stress and inhibit the GO-induced activation and secretion of ECM molecules in vitro. These effects were mediated by the upregulation of Nrf2 nuclear translocation.

Effects of dietary supplementation with ferulic Acid or vitamin e individually or in combination on meat quality and antioxidant capacity of finishing pigs

This study aimed to evaluate the effects of vitamin E (VE), ferulic acid (FA) and their combination supplementation on meat quality and antioxidant capacities of finishing pigs. Sixty barrows were randomly allocated to four experimental diets using a 2×2 factorial arrangement with 2 VE supplemental levels (0 or 400 mg/kg) and 2 FA supplemental levels (0 or 100 mg/kg) in basal diets. After 28 days, six pigs per treatment were slaughtered. The results showed that VE supplementation increased loin eye area of pigs (p<0.05) and FA supplementation increased pH_45min value (p<0.05). The interaction of FA×VE was observed in shear force of longissimus dorsi muscle (p<0.05). Moreover, supplementation with VE decreased hepatic and sarcous malondialdehyde (MDA) content, increased hepatic glutathione (GSH) content and sarcous glutathione peroxidase (GSH-Px) activity (p<0.05). Additionally, supplementation with FA increased hepatic GSH-Px activity and decreased sarcous MDA content (p<0.05). However, dietary treatment did not affect the expression of genes related to nuclear factor, erythroid 2-like 2 (NFE2L2) pathway. These results suggest that dietary FA and VE could partially improve meat quality and antioxidant capacity of finishing pigs, but not by activating NFE2L2 pathway under the normal conditions of farming.

A strategy for effective radioprotection by chitosan-based long-circulating nanocarriers

Effective radioprotection is achieved by chitosan-based long-circulating nanocarriers with radioprotective agents. The stable encapsulation does not reduce its radioprotective capability and exhibits prolonged retention time, thereby showing more beneficial effects.

Ferulic acid attenuates the down-regulation of MEK/ERK/p90RSK signaling pathway in focal cerebral ischemic injury

Ferulic acid provides neuroprotective effects against a middle cerebral artery occlusion (MCAO)-induced cerebral ischemia. Mitogen-activated protein kinases can regulate extensive intracellular processes including cell differentiation, growth, and death. This study further investigated whether ferulic acid modulates a protective mechanism through the activation of Raf-MEK-ERK and its downstream targets, including 90 ribosomal S6 kinase (p90RSK) and Bad during cerebral ischemic injury. Male Sprague-Dawley rats were treated with ferulic acid (100mg/kg) or vehicle after the onset of MCAO and brain tissues were collected 24h after MCAO. These results indicated that ferulic acid decreases the volume of the infarct area and the number of cells positive in terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. Although MCAO injury induces a decrease in the phosphorylation of Raf-1, MEK1/2, and ERK1/2, ferulic acid treatment prevents the injury-induced decrease in these phosphorylation levels. Ferulic acid also attenuates the injury-induced decrease in p90RSK and Bad phosphorylation levels. These findings suggest that ferulic acid prevents MCAO-induced neuronal cell death and that the MEK-ERK-p90RSK-Bad signaling pathway is involved in these neuroprotective effects.

Temozolomide and irradiation combined treatment-induced Nrf2 activation increases chemoradiation sensitivity in human glioblastoma cells

Resistance to chemoradiotherapy is a major obstacle to successful treatment of glioblastoma. Recently, the role of NF-E2-related factor 2 (Nrf2) in enhancing chemoradiation sensitivity has been reported in several types of cancers. Here, we investigated whether temozolomide (TMZ) and irradiation (IR) combined treatment induced Nrf2 activation in human glioblastoma cells. And we further performed a preliminary study about the effect of Nrf2 on chemoradiation sensitivity. Immunohistochemical staining for Nrf2 in paired clinical specimens showed that TMZ and IR combined treatment increased the expression and nuclear localization of Nrf2 in human glioblastoma tissues. Moreover, we found nuclear Nrf2 expression in the glioblastoma tissues obtained from the patients undergoing TMZ and IR combined treatment was associated with the time to tumor recurrence. In vitro, we further verified these findings. First, we detected increased nuclear localization of Nrf2 following treatment with TMZ+IR in human glioblastoma cell lines. Second, we demonstrated TMZ+IR increased the levels of Nrf2 protein in both nuclear and cytoplasmic fractions of U251 cells and induced Nrf2 target genes expression. Finally, downregulating Nrf2 expression increased TMZ+IR-induced cell death in the U251 cells. These findings suggest TMZ+IR combined treatment induces Nrf2 activation in human glioblastoma cells. The activation of Nrf2 may be associate with enhancing chemoradiation sensitivity in human glioblastoma cell. Blocking Nrf2 activation may be a promising method enhancing chemoradiation sensitivity of glioblastoma cells.

In vivo and in vitro demonstration of herb-drug interference in human breast cancer cells treated with tamoxifen and trastuzumab

OBJECTIVE

In recent trends, patients with breast cancer seek integrative medical treatment when receiving either hormonal (tamoxifen [Tam]) or target (trastuzumab) therapy. Our previous in vitro studies demonstrated that the Chinese medicine Si-Wu-Tang (SWT) stimulates MCF-7 cell growth via activation of estrogen receptor α and human epidermal growth factor receptor 2 (HER2) signaling. The present study demonstrates herb-drug interference with cell proliferation in tumor-bearing mice treated with SWT and Tam in vivo and with proliferation capacity in breast cancer cells treated with SWT and trastuzumab in vitro.

METHODS

To assess in vivo SWT + Tam interference, we randomly separated female MCF-7-implanted athymic nude mice into five groups, namely, vehicle (n = 11), estradiol (n = 8), SWT (n = 8), Tam (n = 11), and SWT + Tam (n = 8). All mice were killed after 21 days of treatment. Body weight, uterine weight, tumor volume, and tumor weight were measured. To assess in vitro SWT-trastuzumab interference, we cotreated BT-474 and SK-BR-3 breast cancer cells with SWT and trastuzumab. This was followed by (4,5-cimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assays and cell cycle analysis to measure cell proliferation and by Western blot analysis to analyze protein expression in growth-related signal pathways.

RESULTS

SWT reversed Tam-induced antiproliferative effects on tumor weight and tumor volume and increased estrogen receptor α and N-cadherin expression in the SWT + Tam-treated group compared with the Tam-treated group. Furthermore, SWT reversed trastuzumab-induced antiproliferative activity in HER2 cell lines (SK-BR-3 and BT-474) through increased phosphorylation of the cell cycle regulatory protein p27(Kip1) and possibly of the antiapoptosis protein P38.

CONCLUSIONS

Based on the in vivo and in vitro demonstration of herb-drug interference in breast cancer cells, we conclude that physicians should pay more attention to such interference when treating patients with receptor-positive (estrogen receptor-positive, progesterone receptor-positive, or HER2) breast cancers.

Radioprotective effect of adenine on irradiation-induced apoptosis

AIM

To investigate the radioprotective effect of adenine on irradiated lymphocytes and discover the possible mechanisms of protection.

METHODS

Lymphocytes were pretreated for 12 h with adenine (0.001-0.1 μmol·L(-1)) and then exposed to 4 Gy radiation. Cell viability was observed by the MTS assay, apoptosis was detected by Annexin V-FITC/PI, DNA ladder, and caspase 3/7 activity. Caspase-9, Bax, and Bcl-2 gene expression was investigated by RT-PCR.

RESULTS

Irradiation increased cell death and DNA fragmentation. Pretreatment with adenine significantly reversed this tendency. Furthermore, several anti-apoptotic characteristics of adenine were determined, including the ability to inhibit caspase 3/7, upregulate B-cell lymphoma (Bcl-2) and downregulate Bcl-2- associated X (Bax), capase-9 gene expression in 4 Gy-irradiated AHH-1 cells.

CONCLUSION

The results suggest that adenine had a radioprotective effect to inhibit apoptosis in a concentration dependent manner.

Whole grains, type 2 diabetes, coronary heart disease, and hypertension: links to the aleurone preferred over indigestible fiber

Higher whole grain cereal intakes are associated with substantially lower risks of type 2 diabetes, coronary heart disease, and hypertension. These reduced risks have been established in large prospective studies that now include millions of person-years of follow-up. We analyze the results of 11 major prospective studies to provide recommendations about whole grain consumption. The following review establishes the amount of whole grains that should ideally be consumed based on prospective evidence; defines the nature of whole grains; identifies that the whole grain evidence is robust and not due to confounding; and provides a detailed assessment of several potential mechanisms for the effect of whole grains on health. We draw the following conclusions. Firstly, to maintain health, 40 grams or more of whole grains should be consumed daily. This is about a bowl of whole grain breakfast cereal daily, but 80% of the population does not achieve this. Secondly, aleurone in bran is a critical grain component generally overlooked in favor of indigestible fiber. Live aleurone cells constitute 50% of millers' bran. They store minerals, protein, and the antioxidant ferulic acid, and are clearly more than just indigestible fiber. Finally, we suggest potential roles for magnesium, zinc, and ferulic acid in the development of chronic disease. If the results of prospective studies were applied to the life-style practices of modern societies there exists the potential for enormous personal health and public financial benefits.