The role of oxidative stress during inflammatory processes

Antioxidant and prooxidant effects of Piptadeniastrum africanum as the possible rationale behind its broad scale application in African ethnomedicine

ETHNOPHARMACOLOGICAL RELEVANCE

Piptadeniastrum africanum is widely used in treating oxidative stress related diseases. Oxidative stress, defined as the disturbance in the balance between the production of free radicals and antioxidant defenses, is the root cause of many pathophysiological conditions. Based on the dual properties of prooxidants as toxic and beneficial compounds, both prooxidants and antioxidants may be effective in the treatment of these conditions when the right dose is given to the right subject at the right time for the right duration.

AIM OF THE STUDY

This study was aimed at investigating the in vitro and ex vivo anti- and pro-oxidative effects of P. africanum.

MATERIALS AND METHODS

Total phenolic and flavonoid contents of methanol and aqueous extracts of P. africanum stem back were quantified spectrophotometrically. The methanol extract, ascorbate radicals and reactive oxygen species in brain and liver homogenates of mice treated with the methanol stem bark extract were analyzed by electron paramagnetic resonance (EPR) spectroscopy. Free radical scavenging of DPPH was determined by spectrophotometric and EPR assays.

RESULTS

The methanol extract was richer in both phenolic and flavonoid contents compared to the aqueous extracts and also showed better DPPH radical scavenging capacity. The EPR spectroscopy in vitro analysis exhibited high DPPH scavenging capacity before and after UV irradiation (99.5% and 98.76%) at 40 μg/ml extract. The ex vivo EPR spectroscopy studies demonstrated increased levels of ascorbate radicals (•Asc) in liver and brain homogenates of healthy mice treated with P. africanum in comparison with those of the non treated controls (0.6141 ± 0.026 vs 0.1800 ± 0.0073 arb. units for liver homogenates and 0.9605 ± 0.0492 vs 0.3375 ± 0.0062 arb. units for brain homogenates, correspondingly). Considerably, higher levels of reactive oxygen species (ROS) were measured in mice liver and brain homogenates after treatment with P. africanum extract compared to the control group, as well (1.9402 ± 0.1200 vs 0.6699 ± 0.062 arb. units for liver homogenates and 1.7325 ± 01503 vs 0.3167 ± 0.0403 arb.units, respectively).

CONCLUSION

Therefore, P. africanum exhibited antioxidant and pro-oxidant properties which may explain its broad spectrum use in a wide variety of ailments.

A Review of Immunotherapeutic Strategies in Canine Malignant Melanoma

In dogs, melanomas are relatively common tumors and the most common form of oral malignancy. Biological behavior is highly variable, usually aggressive, and frequently metastatic, with reported survival times of three months for oral or mucosal melanomas in advanced disease stages. Classical clinical management remains challenging; thus, novel and more efficacious treatment strategies are needed. Evidence-based medicine supports the role of the immune system to treat neoplastic diseases. Besides, immunotherapy offers the possibility of a precise medicinal approach to treat cancer. In recent years, multiple immunotherapeutic strategies have been developed, and are now recognized as a pillar of treatment. In addition, dogs represent a good model for translational medicine purposes. This review will cover the most relevant immunotherapeutic strategies for the treatment of canine malignant melanoma, divided among five different categories, namely, monoclonal antibodies, nonspecific immunotherapy activated by bacteria, vaccines, gene therapy, and lymphokine-activated killer cell therapy.

Therapeutic Options Targeting Oxidative Stress, Mitochondrial Dysfunction and Inflammation to Hinder the Progression of Vascular Complications of Diabetes

Type 2 diabetes mellitus is a leading cause of morbidity and mortality worldwide, given its serious associated complications. Despite constant efforts and intensive research, an effective, ubiquitous treatment still eludes the scientific community. As such, the identification of novel avenues of research is key to the potential discovery of this evasive "silver bullet." We focus on this review on the matter of diabetic injury to endothelial tissue and some of the pivotal underlying mechanisms, including hyperglycemia and hyperlipidemia evoked oxidative stress and inflammation. In this sense, we revisited the most promising therapeutic interventions (both non-pharmacological and antidiabetic drugs) targeting oxidative stress and inflammation to hinder progression of vascular complications of diabetes. This review article gives particular attention to the relevance of mitochondrial function, an often ignored and understudied organelle in the vascular endothelium. We highlight the importance of mitochondrial function and number homeostasis in diabetic conditions and discuss the work conducted to address the aforementioned issue by the use of various therapeutic strategies. We explore here the functional, biochemical and bioenergetic alterations provoked by hyperglycemia in the endothelium, from elevated oxidative stress to inflammation and cell death, as well as loss of tissue function. Furthermore, we synthetize the literature regarding the current and promising approaches into dealing with these alterations. We discuss how known agents and therapeutic behaviors (as, for example, metformin, dietary restriction or antioxidants) can restore normality to mitochondrial and endothelial function, preserving the tissue's function and averting the aforementioned complications.

Innate Immunity Provides Biomarkers of Health for Teleosts Exposed to Nanoparticles

In recent years, the unique properties of nanoparticles have fostered novel applications in various fields such as biology, pharmaceuticals, agriculture, and others. Unfortunately, their rapid integration into daily life has also led to environmental concerns due to uncontrolled release of nanoparticles into the aquatic environment. Despite increasing awareness of nanoparticle bioaccumulation in the aquatic environment, much remains to be learned about their impact on aquatic organisms and how to best monitor these effects. Herein, we provide the first review of innate immunity as an emerging tool to assess the health of fish following nanoparticle exposure. Fish are widely used as sentinels for aquatic ecosystem pollution and innate immune parameters offer sensitive and reliable tools that can be harnessed for evaluation of contamination events. The most frequent biomarkers highlighted in literature to date include, but are not limited to, parameters associated with leukocyte dynamics, oxidative stress, and cytokine production. Taken together, innate immunity offers finite and sensitive biomarkers for assessment of the impact of nanoparticles on fish health.

Potential impact of the joint association of total bilirubin and gamma-glutamyltransferase with metabolic syndrome

BACKGROUND

Metabolic syndrome is characterized by the clustering of different metabolic abnormalities. Total bilirubin and gamma-glutamyltransferase (GGT) levels have been reported to be associated with this condition. However, the extent to which the interaction between these parameters affects metabolic syndrome is unknown. Therefore, we examined the association of total bilirubin and GGT levels with metabolic syndrome, and investigated the combined effect of the two parameters.

METHODS

In this retrospective cohort study, we analyzed 8992 middle-aged Japanese subjects (4586 men, 4406 women; mean age, 44.8 ± 9.3 years) without metabolic syndrome from a cohort of employees undergoing annual health examinations. They were divided into four groups according to median total bilirubin and GGT levels: both-low, GGT-high, total bilirubin-high, and both-high. The incident of metabolic syndrome was evaluated during a follow-up of 2.8 ± 1.2 years.

RESULTS

The incident rate of metabolic syndrome during the follow-up was 4.6% in the both-low group, 12.1% in the GGT-high group, 2.7% in the total bilirubin-high group, and 10.6% in the both-high group. Total bilirubin and GGT have an interaction effect on the risk of incident metabolic syndrome (p = 0.0222). The both-low [hazard ratio (HR), 1.37; 95% confidence interval (CI) 1.002-1.89], GGT-high (HR, 1.88; 95% CI 1.42-2.52), and both-high (HR, 2.07; 95% CI 1.56-2.80) groups showed an increased adjusted HR for incident metabolic syndrome after adjusting for covariates compared with the total bilirubin-high group.

CONCLUSIONS

The simultaneous presence of high total bilirubin and low GGT levels may be associated with a lower incidence of metabolic syndrome.

Hydrogen sulfide exposure induces jejunum injury via CYP450s/ROS pathway in broilers

Hydrogen sulfide (H₂S) is generally recognized as a highly poisonous environmental and industrial pollutant. Previous toxicological studies of H₂S are mainly focused on the nervous and cardiovascular system. There are few reports on the H₂S toxicity effects on jejunum to our knowledge. Our study examined the morphological changes and antioxidant functions of broiler jejunum after the 42-day exposure to H₂S. Effects of H₂S on morphological damage and immune function in the broiler jejunum were analyzed from the perspective of CYP450s and oxidative stress via transcriptomics and quantitative real-time PCR (qRT-PCR). It was found that the activities of GPx, CAT, SOD, and T-AOC and the level of GSH were observably decreased (P < 0.05), while the contents of MDA and H₂O₂ were remarkably increased (P < 0.05) in the jejunums of broilers exposed to H₂S, which undergone a process of oxidative stress, and typical inflammatory changes and apoptosis could be observed. Transcriptional profiling results showed that 208 genes were significantly up-regulated while 295 genes were remarkably down-regulated in H₂S group. The expression of CYP450s, inflammation and apoptosis-related genes were also significantly increased. In conclusion, H₂S led to the redox homeostasis disorder through CYP450s differential expression in broiler jejunum. The jejunal inflammatory response, apoptosis along with the immune dysfunction were subsequently observed, which eventually caused jejunal morphology and functional damage. The present study further enriches and perfects the mechanism theory of H₂S toxicity on broilers, which may be valuable for the risk assessment of H₂S and human health protection.

Anti-Oxidant and Anti-Apoptotic Effects of Berberine in Pentylenetetrazole-Induced Kindling Model in Rat

Background and Purpose

Berberine (BBR) is derived from the Berberis species and has demonstrated beneficial effects in various neurodegenerative disorders in animal models. The objective of this study was to evaluate the antiepileptic, antioxidative, and anti-apoptotic effects of BBR in a pentylenetetrazole (PTZ)-induced kindling model of epilepsy in rats.

Methods

A total of 30 male Wistar rats were randomly assigned to receive BBR (100 mg/kg, oral), sodium valproate (200 mg/kg, i.p.), or saline (0.9% NaCl, i.p.) followed by PTZ (35 mg/kg, i.p.) on alternate days until the animal developed kindling or for 10 weeks. Histopathological examination of the hippocampus; DNA fragmentation study; tests for malondialdehyde, superoxide dismutase, glutathione peroxidase, and reduced glutathione; and gene expression studies (nrf2, bcl-2, bax, and caspase 3) were conducted on whole brain tissue after 10 weeks or kindling.

Results

The percentage of kindled animals, histopathological score, malondialdehyde level, and caspase 3 gene expression were significantly lower in the BBR group than in the PTZ group. Superoxide dismutase levels, reduced glutathione levels, and bcl-2 gene expression were significantly higher in the BBR group than in the PTZ group.

Conclusions

The present study demonstrated the anti-epileptogenic effect of BBR, which may be due to antioxidant and anti-apoptotic properties of the PTZ-induced kindling model of epilepsy.

Quercetin, a Plant Polyphenol, Has Potential for the Prevention of Bone Destruction in Rheumatoid Arthritis

We investigated the immune-regulatory function of quercetin, in interleukin (IL)-17-produced osteoclastogenesis in rheumatoid arthritis (RA). RA fibroblasts-like synoviocytes (RA-FLS) were stimulated with IL-17, and the mRNA expression and secretion of receptor activator of nuclear factor kappa-B ligand (RANKL) were detected by real-time polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. CD14⁺ monocytes (osteoclast precursors) were stimulated with IL-17, RANKL, with/without quercetin, and tartrate-resistant acid phosphatase activity was evaluated to assess osteoclast differentiation. Osteoclast differentiation was investigated after coculturing IL-17-stimulated RA-FLS and Th17 cells with monocytes. CD4⁺ T cells were cocultured with quercetin under Th17-inducing conditions, and their differentiation to Th17 cells and Treg cells was determined by flow cytometry analysis. We found that IL-17 stimulated RA-FLS to produce RANKL and quercetin decreased the IL-17-induced RANKL protein levels. Quercetin decreased the IL-17-produced activation of mammalian target of rapamycin, extracellular signal-regulated kinase and inhibitor of kappa B-alpha. When monocytes were stimulated with IL-17, macrophage colony-stimulating factor or RANKL, mature osteoclasts were formed, and quercetin decreased this osteoclastogenesis. When monocytes were cultured with IL-17-prestimulated RA-FLS or Th17 cells, osteoclasts were produced, and quercetin decreased this osteoclast differentiation. In Th17-differentiation conditions, quercetin suppressed Th17 cell and the production of IL-17, but quercetin did not affect Treg cells. Quercetin inhibits IL-17-stimulated RANKL production in RA-FLS and IL-17-stimulated osteoclast formation. Quercetin reduces Th17 differentiation. Quercetin could be an additional therapeutic option for bone destructive processes in RA.

Flavonoids in Ecuadorian Oreocallis grandiflora (Lam.) R. Br.: Perspectives of Use of This Species as a Food Supplement

Oreocallis grandiflora (Lam.) R. Br. is an Ecuadorian species belonging to the Proteaceae family, commonly known as cucharillo (Loja and Zamora provinces), cucharilla (Sierra region), gañal (Bolívar province), and algil (Chimborazo province). Its leaves and flowers, collected during blooming, are traditionally used for oral administration to treat liver diseases, vaginal bleeding, and ovary/uterus inflammation and as digestive, diuretic, and hypoglycemic remedy. Related literature does not report any scientific evidences regarding the chemical composition of the used parts of this species (leaves and flowers), while few indications are reported about the healthy properties of their preparations. Based on these premises, the present research was performed with the objectives to fill the gaps of the chemical and biological knowledge about this species, enriching the knowledge related to the plant biodiversity of Amazonian Ecuador and to the ethnobotanical tradition of Andean communities. Chemical and biological investigation (in vitro antioxidant and anti-inflammatory activity) of flower and leaf hydroalcoholic extracts shed a light on the functional metabolites putatively involved in healthy properties of the O. grandiflora traditional preparations. The chemical fingerprinting achieved by HPTLC and ¹HNMR analyses showed the presence of flavonoids, subsequently quantitatively estimated by AlCl₃ complexation assay and HPLC-DAD. Silica gel chromatography allowed the isolation of the main compounds of the flower extract: quercetin 3-O-β-glucuronide and myricetin 3-O-β-glucuronide. RP-HPLC-DAD-MS analyses showed the presence of quercetin 3-O-rutinoside and isorhamnetin 3-O-rutinoside, in addition to the above-mentioned molecules, in the leaf extract. Regarding the antioxidant (DPPH test, a radical scavenging assay) and anti-inflammatory (WST-1 assay, an oxidative burst test) activities, leaf extract showed the most promising results when compared to the positive controls. The same extract, however, exhibited a higher cytotoxicity compared to the flower extract, indicating the latter preparation as the most interesting anti-inflammatory crude drug.

Conjugate of Enkephalin and Temporin Peptides as a Novel Therapeutic Agent for Sepsis

Antimicrobial peptides (AMPs) exhibit a wide spectrum of actions, ranging from a direct bactericidal effect to multifunctional activities as immune effector molecules. The aim of this study was to examine the anti-inflammatory properties of a DAL-PEG-DK5 conjugate composed of a lysine-rich derivative of amphibian temporin-1CEb (DK5) and dalargin (DAL), the synthetic Leu-enkephalin analogue. Detailed study of the endotoxin-neutralizing activity of the peptide revealed that DAL-PEG-DK5 interacts with LPS and the LPS binding protein (LBP). Moreover, DAL-PEG-DK5 prevented dimerization of TLR4 at the macrophage surface upon LPS stimulation. This inhibited activation of the NF-κB signaling pathway and markedly reduced pro-inflammatory cytokine production. Finally, we showed that aggregation of DAL-PEG-DK5 into amyloid-like structures induced by LPS neutralized the endotoxin proinflammatory activity. Consequently, DAL-PEG-DK5 reduced morbidity and mortality in vivo, in a mouse model of endotoxin-induced septic shock. Collectively, the data suggest that DAL-PEG-DK5 is a promising therapeutic compound for sepsis.

Reactive oxygen species (ROS) in macrophage activation and function in diabetes

In a diabetic milieu high levels of reactive oxygen species (ROS) are induced. This contributes to the vascular complications of diabetes. Recent studies have shown that ROS formation is exacerbated in diabetic monocytes and macrophages due to a glycolytic metabolic shift. Macrophages are important players in the progression of diabetes and promote inflammation through the release of pro-inflammatory cytokines and proteases. Because ROS is an important mediator for the activation of pro-inflammatory signaling pathways, obesity and hyperglycemia-induced ROS production may favor induction of M1-like pro-inflammatory macrophages during diabetes onset and progression. ROS induces MAPK, STAT1, STAT6 and NFκB signaling, and interferes with macrophage differentiation via epigenetic (re)programming. Therefore, a comprehensive understanding of the impact of ROS on macrophage phenotype and function is needed in order to improve treatment of diabetes and its vascular complications. In the current comprehensive review, we dissect the role of ROS in macrophage polarization, and analyze how ROS production links metabolism and inflammation in diabetes and its complications. Finally, we discuss the contribution of ROS to the crosstalk between macrophages and endothelial cells in diabetic complications.

TLR5 silencing reduced hyperammonaemia-induced liver injury by inhibiting oxidative stress and inflammation responses via inactivating NF-κB and MAPK signals

BACKGROUND

Liver injury is a serious threat for human health and life. Toll-like receptor 5 (TLR5) has reported to be a vital mediator in flagellin or tetrachloride (CCl4)-induced liver injury. However, the roles and etiology of TLR5 in hyperammonaemia (HA)-induced liver injury are poor defined.

METHODS

HA rats were generated by intragastric administration using ammonium chloride solution. Liver status was assessed by haematoxylin and eosin (H&E) staining and measuring serum levels of liver injury markers. Immunohistochemistry (IHC) assay was used to visualize protein expression in tissues. Apoptotic index in tissues was determined by TUNEL assay. RT-qPCR assay was employed to test mRNA expression. Oxidative stress responses was assessed by detecting levels of reactive oxygen species (ROS) and related indicators. NF-κB activity was examined by TransAM NF-κB colorimetric kit.

RESULTS

TLR5 was highly expressed in liver tissues of HA rats. TLR5 knockdown ameliorated HA-induced liver injury by inhibiting liver cell apoptosis. TLR5 depletion inhibited HA-induced pro-inflammatory cytokine expression in liver tissues, but had no effect on the infiltration of T and macrophage cells into liver tissues. TLR5 silencing impaired HA-induced oxidative stress responses in hepatocytes, but not in hepatic stellate cells (HSCs). TLR5 downregulation inhibited HA-induced activation on TLR5/NF-κB and TLR5/MAPK signaling pathways.

CONCLUSION

TLR5 silencing reduced HA-induced liver injury by inhibiting hepatocyte apoptosis, oxidative stress and inflammation responses via inactivating NF-κB and MAPK signals, deepening our understanding on the molecular mechanism of HA-induced liver injury and providing a potential therapeutic target for alleviating liver injury.

Hydrogen sulfide inhalation-induced immune damage is involved in oxidative stress, inflammation, apoptosis and the Th1/Th2 imbalance in broiler bursa of Fabricius

Hydrogen sulfide (H₂S) is widely accepted to be a signaling molecule that exhibits some potentially beneficial therapeutic effects at physiological concentrations. At elevated levels, H₂S is highly toxic and has a negative effect on human health and animal welfare. Studies have shown that H₂S exposure induces an immune function in mice, but there are few studies of the effect of continuous H₂S exposure on immune organs in poultry. In this study, one-day-old broilers were selected and exposed to 4 or 20 ppm of H₂S gas for 14, 28 and 42 days of age. After exposure, the bursa of Fabricius (BF) was harvested. The results showed that continuous H₂S exposure reduced the body weight, abdominal fat percentage, and antibody titer in broilers. H₂S exposure also decreased mRNA expression of IgA, IgM and IgG in the broiler BF. A histological study revealed obvious nuclear debris, and a few vacuoles in the BF, and an ultrastructural study revealed mitochondrial and nuclear damage to BF cells after H₂S exposure for 42 d. Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay suggested H₂S exposure remarkably increased the number of TUNEL positive nuclei and significantly increased apoptotic index. The expression of apoptotic genes also confirmed that H₂S inhalation damaged the broiler BF. Increased cytokines and reduced antioxidant responses were detected in the BF after exposure to H₂S. Cytokines promoted inflammation and caused a Th1/Th2 imbalance. We suggest that continuous H₂S intoxication triggers oxidative stress, inflammation, apoptosis and a Th1/Th2 imbalance in the BF, leading to immune injury in broilers.

Polymorphisms in the anti-oxidant paraoxonase-1 (PON1) gene associated with fertility of postpartum dairy cows

Paraoxonase 1 (PON1) is a negative acute phase plasma protein synthesized by the liver that has anti-oxidant activity. The aim of this study was to evaluate the association of single nucleotide polymorphisms (SNPs) in the PON1 promoter region with plasma PON1 activity and fertility in Holstein dairy cows. Sixty-eighty Holstein cows were used in this initial investigative study. Blood samples were collected weekly beginning 28 days prior to expected calving, twice weekly in week 1 and 2 postpartum, and then once weekly through 6 weeks postpartum for plasma PON1 activity analysis. Cows were synchronized for ovulation and timed AI at 63-70 DIM using an Ovsynch program. Pregnancy diagnosis was confirmed by rectal palpation and reproductive performance data was recorded until 210 DIM. DNA was extracted from blood of each cow and a fragment of proximal PON1 gene promoter was sequenced. Seven single nucleotide polymorphisms (SNPs) were identified in the promoter region of the PON1 gene at positions -22, -105, -176, -221, -392, -611 and -676, six of which were significantly associated with plasma PON1 activity level. The SNPs -221 and -392 were significantly associated with both plasma PON1 activity and the calving to conception interval (P < 0.05) with no significant effect on calving to first ovulation interval. In conclusion, the genotypes associated with higher plasma PON1 activity in SNP locations -221 and -392 were also associated with a reduced calving to conception interval in this study set of cows. These SNPs may provide novel genetic markers for improved fertility in future larger studies in dairy cows.

Dietary Antioxidants, Circulating Antioxidant Concentrations, Total Antioxidant Capacity, and Risk of All-Cause Mortality: A Systematic Review and Dose-Response Meta-Analysis of Prospective Observational Studies

The associations of various dietary or circulating antioxidants with the risk of all-cause mortality in the general population have not been established yet. A systematic search was performed in PubMed and Scopus, from their inception up to October 2017. Prospective observational studies reporting risk estimates of all-cause mortality in relation to dietary intake and/or circulating concentrations of antioxidants were included. Random-effects meta-analyses were conducted. Forty-one prospective observational studies (total n = 507,251) involving 73,965 cases of all-cause mortality were included. The RRs of all-cause mortality for the highest compared with the lowest category of circulating antioxidant concentrations were as follows: total carotenes, 0.60 (95% CI: 0.46, 0.74); vitamin C, 0.61 (95% CI: 0.53, 0.69); selenium, 0.62 (95% CI: 0.45, 0.79); β-carotene, 0.63 (95% CI: 0.57, 0.70); α-carotene, 0.68 (95% CI: 0.58, 0.78); total carotenoids, 0.68 (95% CI: 0.56, 0.80); lycopene, 0.75 (95% CI: 0.54, 0.97); and α-tocopherol, 0.84 (95% CI: 0.77, 0.91). The RRs for dietary intakes were: total carotenoids, 0.76 (95% CI: 0.66, 0.85); total antioxidant capacity, 0.77 (95% CI: 0.73, 0.81); selenium, 0.79 (95% CI: 0.73, 0.85); α-carotene, 0.79 (95% CI: 0.63, 0.94); β-carotene, 0.82 (95% CI: 0.77, 0.86); vitamin C, 0.88 (95% CI: 0.83, 0.94); and total carotenes, 0.89 (95% CI: 0.81, 0.97). A nonsignificant inverse association was found for dietary zinc, zeaxanthin, lutein, and vitamin E. The nonlinear dose-response meta-analyses demonstrated a linear inverse association in the analyses of dietary β-carotene and total antioxidant capacity, as well as in the analyses of circulating α-carotene, β-carotene, selenium, vitamin C, and total carotenoids. The association appeared to be U-shaped in the analyses of serum lycopene and dietary vitamin C. The present study indicates that adherence to a diet with high antioxidant properties may reduce the risk of all-cause mortality. Our results confirm current recommendations that promote higher intake of antioxidant-rich foods such as fruit and vegetables.

Inflammatory mechanisms and oxidative stress in prostatitis: the possible role of antioxidant therapy

This article focuses on the role that oxidative stress plays in chronic prostatitis, not only with respect to the known impact on symptoms and fertility but also especially in relation to possible prostate cancer development. Prostatitis is the most common urologic disease in adult males younger than 50 years and the third most common urologic diagnosis in males older than 50 years. If the germ-causing acute prostatitis is not eliminated, the inflammatory process becomes chronic. Persistent inflammation causes ongoing production of large quantities of pro-inflammatory cytokines and both oxygen and nitrogen reactive species, with consequent activation of transcription factor nuclear factor-kappa B (NF-κB) and genes encoding for further production of pro-inflammatory cytokines, chemotactic factors, and growth factors. Confirming the role of oxidative stress in chronic prostatitis, several studies have demonstrated the presence of oxidative stress markers in the genital secretions of patients suffering from the disease. Antioxidants can therefore play an essential role in the treatment of chronic bacterial and non-bacterial prostatitis; in the case of bacterial inflammation, they can be associated with antibiotic therapy. Moreover, due to their anti-inflammatory properties, antioxidants hinder the progression of inflammation and the possible development of prostate cancer.

Phenolic Compounds in Honey and Their Associated Health Benefits: A Review

Honey is a natural substance appreciated for its therapeutic abilities since ancient times. Its content in flavonoids and phenolic acids plays a key role on human health, thanks to the high antioxidant and anti-inflammatory properties that they exert. Honey possesses antimicrobial capacity and anticancer activity against different types of tumors, acting on different molecular pathways that are involved on cellular proliferation. In addition, an antidiabetic activity has also been highlighted, with the reduction of glucose, fructosamine, and glycosylated hemoglobin serum concentration. Honey exerts also a protective effect in the cardiovascular system, where it mainly prevents the oxidation of low-density lipoproteins, in the nervous system, in the respiratory system against asthma and bacterial infections, and in the gastrointestinal system. A beneficial effect of honey can also be demonstrated in athletes. The purpose of this review is to summarize and update the current information regarding the role of honey in health and diseases.

Triptriolide Alleviates Lipopolysaccharide-Induced Liver Injury by Nrf2 and NF-κB Signaling Pathways

Nrf2 (Nuclear Factor Erythroid 2 Related Factor 2) transcription factor not only regulates oxidative stress response, but also represses inflammation by regulating cytokines production and cross-talking with NF-κB signaling pathways. Nrf2 plays an essential role in liver injury induced by oxidative stress and inflammation. Triptriolide (T11) is a minor component of Tripterygium wilfordii Hook F. (TwHF), which can be obtained by hydrolysis reaction of triptolide (T9). The major purpose of this study is to clarify the regulating effects of T11 on oxidative stress and inflammation in vivo and in vitro. LPS-stimulated RAW 264.7 cells were used to verify the regulating effects of T11 on oxidative stress (ROS and Nrf2 signaling pathway) and inflammatory cytokines production (TNF-α, IL-6 and IL-1β). The antioxidant responsive element (ARE) luciferase assay was employed to evaluate Nrf2 activation effect of T11 in HEK-293T cells. Lipopolysaccharides (LPS) induced acute liver injury (ALI) in BALB/c mice were used to study the protective effects (ALT, AST, MDA, SOD, histopathology and neutrophils/macrophages filtration) and the underlying protection mechanisms of ALI amelioration (Nrf2 and NF-κB signaling pathway) of T11. Firstly, the results showed that T11 can not only effectively decrease the productions of inflammatory cytokines (TNF-α, IL-6 and IL-1β), ROS and NO in LPS-stimulated RAW 264.7 cells, but also further significantly increase the activity of Nrf2 in HEK-293T cells. Secondly, the results suggested that T11 could dramatically decrease the oxidative stress responses (SOD and MDA) and inflammation (histopathology, neutrophils/macrophages filtration, TNF-α, IL-6 and IL-1β production) in LPS-induced ALI in BALB/c mice. Finally, the results implied that T11 could dramatically increase Nrf2 protein expression and decrease p-TAK1, p-IκBα and NF-κB protein expression both in vivo and in vitro. In conclusion, our findings indicated that T11 could alleviate LPS induced oxidative stress and inflammation by regulating Nrf2 and NF-κB signaling pathways in vitro and in vivo, which offers a novel insights for the application of TwHF in clinical.

Metabolomic profiling implicates adiponectin as mediator of a favorable lipoprotein profile associated with NT-proBNP

Background

The N-terminal prohormone of brain natriuretic peptide (NT-proBNP) is an important biomarker for the diagnosis of heart failure. Apart from this and only recently recognized, NT-proBNP levels associate with higher HDL- and lower LDL-cholesterol levels comprising a favorable blood lipid profile. To further examine this observation, the lipoprotein profile in relation to NT-proBNP was examined in-depth by proton nuclear magnetic resonance spectroscopy (¹H-NMR). We complemented this investigation with a state-of-the-art untargeted metabolomics approach.

Methods

Lipoprotein particles were determined by ¹H-NMR spectroscopy in 872 subjects without self-reported diabetes from the population-based Study of Health in Pomerania (SHIP)-TREND with available NT-proBNP measurements. Comprehensive metabolomics data for plasma and urine samples were obtained. Linear regression models were performed to assess the associations between serum concentrations of NT-proBNP and the metabolites/lipoprotein particles measured in plasma or urine.

Results

An increase in serum NT-proBNP was associated with a benefical lipoprotein profile, including a decrease in VLDL, IDL and LDL-particles along with an increase in large HDL particles. These findings were replicated in a second independent cohort. Serum concentrations of NT-proBNP showed significant inverse associations with seven plasma metabolites while associations with 39 urinary metabolites, mostly comprising amino acids and related intermediates, were identified. Mediation analyses revealed adiponection as mediating factor for the associations observed with lipoproteins particles.

Conclusions

Most of the metabolic changes associated with NT-proBNP implicate significant influence on the blood lipid profile besides vasodilatory and the diuretic action of BNP signaling. Our data suggest that the more favorable lipoprotein profile as associated with elevated NT-proBNP concentrations in mainly cardiac healthy individuals might relate to adiponectin signaling indicating even indirect cardio-protective effects for NT-proBNP.

Electronic supplementary material

The online version of this article (10.1186/s12933-018-0765-1) contains supplementary material, which is available to authorized users.

New Insights in the Pathogenesis of HPV Infection and the Associated Carcinogenic Processes: The Role of Chronic Inflammation and Oxidative Stress

Human papillomavirus (HPV) is a small double-stranded DNA virus with tropism for epithelial cells. To this date, over 150 genotypes are known and are classified into two major groups, low-risk and high-risk strains, depending on the ability of the virus to induce malignant transformation. The host's immunity plays a central role in the course of the infection; therefore, it may not be clinically manifest or may produce various benign or malignant lesions. The pathogenic mechanisms are complex and incompletely elucidated. Recent research suggests the role of chronic inflammation and oxidative stress (OS) in the pathogenesis of HPV infection and the associated carcinogenic processes. Chronic inflammation induces OS, which in turn promotes the perpetuation of the inflammatory process resulting in the release of numerous molecules which cause cell damage. Reactive oxygen species exert a harmful effect on proteins, lipids, and nucleic acids. Viral oncogenes E5, E6, and E7 are involved in the development of chronic inflammation through various mechanisms. In addition, HPV may interfere with redox homeostasis of host cells, inducing OS which may be involved in the persistence of the infection and play a certain role in viral integration and promotion of carcinogenesis. Knowledge regarding the interplay between chronic inflammation and OS in the pathogenesis of HPV infection and HPV-induced carcinogenesis has important consequences on the development of new therapeutic strategies.

Oxidative damage in glutaric aciduria type I patients and the protective effects of l-carnitine treatment

The deficiency of the enzyme glutaryl-CoA dehydrogenase, known as glutaric acidemia type I (GA-I), leads to the accumulation of glutaric acid (GA) and glutarilcarnitine (C5DC) in the tissues and body fluids, unleashing important neurotoxic effects. l-carnitine (l-car) is recommended for the treatment of GA-I, aiming to induce the excretion of toxic metabolites. l-car has also demonstrated an important role as antioxidant and anti-inflammatory in some neurometabolic diseases. This study evaluated GA-I patients at diagnosis moment and treated the oxidative damage to lipids, proteins, and the inflammatory profile, as well as in vivo and in vitro DNA damage, reactive nitrogen species (RNS), and antioxidant capacity, verifying if the actual treatment with l-car (100 mg kg^-1  day^-1 ) is able to protect the organism against these processes. Significant increases of GA and C5DC were observed in GA-I patients. A deficiency of carnitine in patients before the supplementation was found. GA-I patients presented significantly increased levels of isoprostanes, di-tyrosine, urinary oxidized guanine species, and the RNS, as well as a reduced antioxidant capacity. The l-car supplementation induced beneficial effects reducing these biomarkers levels and increasing the antioxidant capacity. GA, in three different concentrations, significantly induced DNA damage in vitro, and the l-car was able to prevent this damage. Significant increases of pro-inflammatory cytokines IL-6, IL-8, GM-CSF, and TNF-α were shown in patients. Thus, the beneficial effects of l-car presented in the treatment of GA-I are due not only by increasing the excretion of accumulated toxic metabolites, but also by preventing oxidative damage.

Dietary n-3 but not n-6 fatty acids down-regulate maternal dyslipidemia induced inflammation: A three-generation study in rats

This study addresses the effects of n-3 and n-6 fatty acids in maternal dyslipidemia induced inflammation over three generation in rats. The detailed protocol for animal feeding and mating is described in the methodology. Placenta and fetal liver were isolated on the eighteenth day of gestation and delivered pups after lactation were kept on their maternal diets. Compared to control and experimental groups, high-fat fed rats (HFL) had a higher level of cytokines and eicosanoids in serum (p < 0.05). Liver and uterine expression of cPLA-2, Cox-2, 5-Lox, EP-1, BLT-1, and ICAM-1 were higher (p < 0.05) in HFL group. NF-kB and Nrf-2 levels in placenta and fetal liver were beneficially modulated by n-3 but not n-6 fatty acids. Offspring of dyslipidemic mothers' exhibit amplified inflammatory markers when continued on diets of their mothers. Incorporation of n-3 but not n-6 fatty acids down-regulated maternal dyslipidemia induced inflammatory markers.

The Pathogenesis of Diabetes Mellitus by Oxidative Stress and Inflammation: Its Inhibition by Berberine

A substantial knowledge on the pathogenesis of diabetes mellitus (DM) by oxidative stress and inflammation is available. Berberine is a biologically active botanical that can combat oxidative stress and inflammation and thus ameliorate DM, especially type 2 DM. This article describes the potential of berberine against oxidative stress and inflammation with special emphasis on its mechanistic aspects. In diabetic animal studies, the modified levels of proinflammatory cytokines and oxidative stress markers were observed after administering berberine. In renal, fat, hepatic, pancreatic and several others tissues, berberine-mediated suppression of oxidative stress and inflammation was noted. Berberine acted against oxidative stress and inflammation through a very complex mechanism consisting of several kinases and signaling pathways involving various factors, including NF-κB (nuclear factor-κB) and AMPK (AMP-activated protein kinases). Moreover, MAPKs (mitogen-activated protein kinases) and Nrf2 (nuclear factor erythroid-2 related factor 2) also have mechanistic involvement in oxidative stress and inflammation. In spite of above advancements, the mechanistic aspects of the inhibitory role of berberine against oxidative stress and inflammation in diabetes mellitus still necessitate additional molecular studies. These studies will be useful to examine the new prospects of natural moieties against DM.

Hydrogen peroxide-mediated oxidative stress induces inflammasome activation in term human placental explants

BACKGROUND

The placenta is a multifunctional organ that can suffer with imbalances between pro- and antioxidant molecules, contributing for inflammatory imbalance. The inflammation generated by oxidative stress may induce inflammasome activation, an essential complex for pro-inflammatory cytokine production.

OBJECTIVE

The aim of this study was to evaluate whether hydrogen peroxide (H₂O₂) mediated oxidative stress induces inflammasome activation on placental explants.

STUDY DESIGN

Tissue cultures of placental explants obtained from normotensive pregnant women were performed in different concentrations of H₂O₂. Gene expressions of NLRP3, caspase-1, IL-1β, TNF-α and IL-10 were evaluated by qPCR. Superoxide dismutase (SOD), catalase, Heat shock protein 70 (Hsp70), Caspase-1, TNF-α, IL-1β, IL-10 and human Chorionic Gonadotropin (hCG) were determined by ELISA.

RESULTS

Concentrations of catalase, Hsp70, hCG and SOD were higher in cultures with 100 and 1000 µM H₂O₂ compared to controls. Gene and protein expressions of TNF-α and IL-1β were elevated in cultures with 1000 μM H₂O₂ compared to controls. This concentration led to inflammasome activation, by increasing gene expressions of NLRP3, caspase-1 and IL-1β. In contrast, gene and protein expressions of IL-10 were reduced at 100 and 1000 μM H₂O₂. Protein expression of caspase-1 was higher in cultures of 100 μM H₂O₂ compared to controls. Treatment with Glybenclamide at 200 μM was used to prevent NLRP3 inflammasome activation. This concentration reduced protein expression of caspase-1 compared to culture with only H₂O₂ and control cultures.

CONCLUSIONS

Our results confirm that H₂O₂ induces oxidative stress on placental explants and demonstrate that cell responses to this stress involve inflammasome activation.

Source and amount of carbohydrate in the diet and inflammation in women with polycystic ovary syndrome

High carbohydrate intake and low-grade inflammation cooperate with insulin resistance and hyperandrogenism to constitute an interactive continuum acting on the pathophysiology of polycystic ovary syndrome (PCOS), the most common endocrine disorder in women of reproductive age characterised by oligo-anovulatory infertility and cardiometabolic disorders. The role of insulin in PCOS is pivotal both in regulating the activity of ovarian and liver enzymes, respectively involved in androgen production and in triggering low-grade inflammation usually reported to be associated with an insulin resistance, dyslipidaemia and cardiometabolic diseases. Although an acute hyperglycaemia induced by oral glucose loading may increase inflammation and oxidative stress by generating reactive oxygen species through different mechanisms, the postprandial glucose increment, commonly associated with the Western diet, represents the major contributor of chronic sustained hyperglycaemia and pro-inflammatory state. Together with hyperinsulinaemia, hyperandrogenism and low-grade inflammation, unhealthy diet should be viewed as a key component of the 'deadly quartet' of metabolic risk factors associated with PCOS pathophysiology. The identification of a tight diet-inflammation-health association makes the adoption of healthy nutritional approaches a primary preventive and therapeutic tool in women with PCOS, weakening insulin resistance and eventually promoting improvements of reproductive life and endocrine outcomes. The intriguing nutritional-endocrine connections operating in PCOS underline the role of expert nutritionists in the management of this syndrome. The aim of the present review is to provide an at-a-glance overview of the possible bi-directional mechanisms linking inflammation, androgen excess and carbohydrate intake in women with PCOS.

Cellular Stresses and Stress Responses in the Pathogenesis of Insulin Resistance

Insulin resistance (IR), a key component of the metabolic syndrome, precedes the development of diabetes, cardiovascular disease, and Alzheimer's disease. Its etiological pathways are not well defined, although many contributory mechanisms have been established. This article summarizes such mechanisms into the hypothesis that factors like nutrient overload, physical inactivity, hypoxia, psychological stress, and environmental pollutants induce a network of cellular stresses, stress responses, and stress response dysregulations that jointly inhibit insulin signaling in insulin target cells including endothelial cells, hepatocytes, myocytes, hypothalamic neurons, and adipocytes. The insulin resistance-inducing cellular stresses include oxidative, nitrosative, carbonyl/electrophilic, genotoxic, and endoplasmic reticulum stresses; the stress responses include the ubiquitin-proteasome pathway, the DNA damage response, the unfolded protein response, apoptosis, inflammasome activation, and pyroptosis, while the dysregulated responses include the heat shock response, autophagy, and nuclear factor erythroid-2-related factor 2 signaling. Insulin target cells also produce metabolites that exacerbate cellular stress generation both locally and systemically, partly through recruitment and activation of myeloid cells which sustain a state of chronic inflammation. Thus, insulin resistance may be prevented or attenuated by multiple approaches targeting the different cellular stresses and stress responses.

Neuroinflammation in Amyotrophic Lateral Sclerosis: Role of Redox (dys)Regulation

SIGNIFICANCE

Amyotrophic lateral sclerosis (ALS) is due to degeneration of upper and lower motor neurons in the anterior horn of the spinal cord and in the motor cortex. Mechanisms leading to motor neuron death are complex and currently the disease is untreatable. Recent Advances: Work in genetic models of ALS indicates that an imbalance in the cross talk that physiologically exists between motor neurons and the surrounding cells is eventually detrimental to motor neurons. In particular, the cascade of events collectively known as neuroinflammation and mainly characterized by a reactive phenotype of astrocytes and microglia, moderate infiltration of peripheral immune cells, and elevated levels of inflammatory mediators has been consistently observed in motor regions of the central nervous system (CNS) in sporadic and familial ALS, constituting a hallmark of the disease. Resident glial cells and infiltrated immune cells are considered among the major producers of reactive species of oxygen and nitrogen in pathological conditions of the CNS, including motor neuron diseases.

CRITICAL ISSUES

The timing and exact role of oxidative stress-mediated neuroinflammation and damage to motor neurons in ALS are still not fully elucidated.

FUTURE DIRECTIONS

It is clear that a major challenge in the next future will be to envisage effective strategies to modulate the neuroinflammatory response in the symptomatic stage of disease, to prevent progression of neurodegeneration through the propagation of oxidative damage. Antioxid. Redox Signal. 29, 15-36.

Zeolite-loaded alginate-chitosan hydrogel beads as a topical hemostat

Hemorrhage is the leading cause of preventable death after a traumatic injury, and the largest contributor to loss of productive years of life. Hemostatic agents accelerate hemostasis and help control hemorrhage by concentrating coagulation factors, acting as procoagulants and/or interacting with erythrocytes and platelets. Hydrogel composites offer a platform for targeting both mechanical and biological hemostatic mechanisms. The goal of this work was to develop hydrogel particles composed of chitosan, alginate, and zeolite, and to assess their potential to promote blood coagulation via multiple mechanisms: erythrocyte adhesion, factor concentration, and the ability to serve as a mechanical barrier to blood loss. Several particle compositions were synthesized and characterized. Hydrogel bead composition was optimized to achieve the highest swelling capacity, greatest erythrocyte adhesion, and minimal in vitro cytotoxicity. These results suggest a polymer hydrogel-aluminosilicate composite material may serve as a platform for an effective hemostatic agent that incorporates multiple mechanisms of action. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1662-1671, 2018.

Essential Dietary Bioactive Lipids in Neuroinflammatory Diseases

SIGNIFICANCE

Under physiological conditions, neurons and glia are in a healthy, redox-balanced environment; when injury perturbs this equilibrium, a neuroinflammatory state is established by activated microglia that triggers pro-inflammatory responses and alters the oxidant/antioxidant balance, thus leading to neuronal loss and neurodegeneration. In neurodegenerative diseases (such as Alzheimer's disease, Parkinson's disease, amyothrophic lateral sclerosis, and multiple sclerosis), the brain is in a constitutively self-sustaining cycle of inflammation and oxidative stress that prompts and amplifies brain damage. Recent Advances: Recently, an increasing amount of scientific data highlight the ability of specific nutrients to cross the blood-brain barrier, and to modulate inflammatory and oxidative pathways. Therefore, nutritional approaches may contribute to restore the lost equilibrium among factors accounting for neurodegeneration.

CRITICAL ISSUES

Herein, we critically examine how essential lipids (including fatty acids, liposoluble vitamins and phytosterols) might contribute to accelerate or prevent the onset and progression of such pathologies. In particular, we highlight that experimental and clinical findings, although promising, are still inadequate to draw definitive conclusions.

FUTURE DIRECTIONS

More research is warranted in order to establish the real impact of lipid intake on brain health, especially when redox balance and inflammatory responses have been already compromised. In the future, it would be hoped to gain a detailed knowledge of chemical modifications and dynamic properties of such nutrients, before planning to exploit them as potential therapeutics. Antioxid. Redox Signal. 29, 37-60.

Dietary Inflammatory Index and Site-Specific Cancer Risk: A Systematic Review and Dose-Response Meta-Analysis

Existing evidence suggests a link between the inflammatory potential of diet and risk of cancer. This study aimed to test the linear and potential nonlinear dose-response associations of the Dietary Inflammatory Index (DII), as being representative of inflammatory features of the diet, and site-specific cancer risk. A systematic search was conducted with the use of PubMed and Scopus from 2014 to November 2017. Prospective cohort or case-control studies reporting the risk estimates of any cancer type for ≥3 categories of the DII were selected. Studies that reported the association between continuous DII score and cancer risk were also included. Pooled RRs were calculated by using a random-effects model. Eleven prospective cohort studies (total n = 1,187,474) with 28,614 incident cases and 29 case-control studies with 19,718 cases and 33,229 controls were identified. The pooled RRs for a 1-unit increment in the DII were as follows: colorectal cancer, 1.06 (95% CI: 1.04, 1.08; I2 = 72.5%; n = 9); breast cancer, 1.03 (95% CI: 1.00, 1.07; I2 = 84.0%; n = 7); prostate cancer, 1.06 (95% CI: 0.97, 1.15; I2 = 56.2%; n = 6); pancreatic cancer, 1.16 (95% CI: 1.05, 1.28; I2 = 61.6%; n = 2); ovarian cancer, 1.08 (95% CI: 1.03, 1.13; I2 = 0%; n = 2); esophageal squamous cell carcinoma, 1.24 (95% CI: 1.10, 1.38; I2 = 64.3%; n = 2); renal cell carcinoma, 1.08 (95% CI: 1.02, 1.13; I2 = 0%; n = 2); and esophageal adenocarcinoma, 1.26 (95% CI: 1.13, 1.39; I2 = 0%; n = 2). A nonlinear dose-response meta-analysis showed that, after a somewhat unchanged risk within initial scores of the DII, the risk of colorectal cancer increased linearly with increasing DII score. In the analyses of breast and prostate cancers, the risk increased with a very slight trend with increasing DII score. In conclusion, the results showed that dietary habits with high inflammatory features might increase the risk of site-specific cancers.

Antidiabetic Activity and Chemical Composition of Sanbai Melon Seed Oil

Objectives

Many fruits and herbs had been used in Traditional Chinese Medicines for treating diabetes mellitus (DM); however, scientific and accurate evidences regarding their efficacy and possible mechanisms were largely unknown. Sanbai melon seed oil (SMSO) was used in folk medicine in treating DM, but there is no literature about these effects. The present study was aimed at confirming the treatment effects of SMSO in type 1 DM.

Methods

Diabetes was induced by single intraperitoneal injection of streptozotocin (STZ) at a dose of 65 mg/kg body weight. After diabetes induction, mice were treated with SMSO at dose of 1 g/kg, 2 g/kg, and 4 g/kg. Drugs were given by gavage administration once a day continuously for 28 days. At the end of treatment, several biochemical parameters and molecular mechanisms were determined by biochemical assays, ELISA, and Western blotting. The chemical compositions of SMSO were also tested.

Results

SMSO treatment significantly improved the symptoms of weight loss, polydipsia, reduced FBG level, increased plasma insulin levels, reduced plasma lipids levels, and protected islet injury. The results also showed that SMSO mitigated oxidative stress and alleviated the liver and renal injury in diabetes mice. SMSO also protected islet cells from apoptotic damage by suppressing ER mediated and mitochondrial dependent apoptotic pathways. Further constituent analysis results showed that SMSO had rich natural resources which had beneficial effects on DM.

Conclusions

This study showed that SMSO had excellent antidiabetes effect and provided scientific basis for the use of SMSO as the functional ingredients production and dietary supplements production in the food and pharmaceutical industries.

Experimental Nonalcoholic Steatohepatitis and Liver Fibrosis Are Ameliorated by Pharmacologic Activation of Nrf2 (NF-E2 p45-Related Factor 2)

BACKGROUND & AIMS

Nonalcoholic steatohepatitis (NASH) is associated with oxidative stress. We surmised that pharmacologic activation of NF-E2 p45-related factor 2 (Nrf2) using the acetylenic tricyclic bis(cyano enone) TBE-31 would suppress NASH because Nrf2 is a transcriptional master regulator of intracellular redox homeostasis.

METHODS

Nrf2+/+ and Nrf2-/- C57BL/6 mice were fed a high-fat plus fructose (HFFr) or regular chow diet for 16 weeks or 30 weeks, and then treated for the final 6 weeks, while still being fed the same HFFr or regular chow diets, with either TBE-31 or dimethyl sulfoxide vehicle control. Measures of whole-body glucose homeostasis, histologic assessment of liver, and biochemical and molecular measurements of steatosis, endoplasmic reticulum (ER) stress, inflammation, apoptosis, fibrosis, and oxidative stress were performed in livers from these animals.

RESULTS

TBE-31 treatment reversed insulin resistance in HFFr-fed wild-type mice, but not in HFFr-fed Nrf2-null mice. TBE-31 treatment of HFFr-fed wild-type mice substantially decreased liver steatosis and expression of lipid synthesis genes, while increasing hepatic expression of fatty acid oxidation and lipoprotein assembly genes. Also, TBE-31 treatment decreased ER stress, expression of inflammation genes, and markers of apoptosis, fibrosis, and oxidative stress in the livers of HFFr-fed wild-type mice. By comparison, TBE-31 did not decrease steatosis, ER stress, lipogenesis, inflammation, fibrosis, or oxidative stress in livers of HFFr-fed Nrf2-null mice.

CONCLUSIONS

Pharmacologic activation of Nrf2 in mice that had already been rendered obese and insulin resistant reversed insulin resistance, suppressed hepatic steatosis, and mitigated against NASH and liver fibrosis, effects that we principally attribute to inhibition of ER, inflammatory, and oxidative stress.

Recent advances in understanding hematopoiesis in Fanconi Anemia

Fanconi anemia is an inherited disease characterized by genomic instability, hypersensitivity to DNA cross-linking agents, bone marrow failure, short stature, skeletal abnormalities, and a high relative risk of myeloid leukemia and epithelial malignancies. The 21 Fanconi anemia genes encode proteins involved in multiple nuclear biochemical pathways that effect DNA interstrand crosslink repair. In the past, bone marrow failure was attributed solely to the failure of stem cells to repair DNA. Recently, non-canonical functions of many of the Fanconi anemia proteins have been described, including modulating responses to oxidative stress, viral infection, and inflammation as well as facilitating mitophagic responses and enhancing signals that promote stem cell function and survival. Some of these functions take place in non-nuclear sites and do not depend on the DNA damage response functions of the proteins. Dysfunctions of the canonical and non-canonical pathways that drive stem cell exhaustion and neoplastic clonal selection are reviewed, and the potential therapeutic importance of fully investigating the scope and interdependences of the canonical and non-canonical pathways is emphasized.

Oxidative Stress as a Primary Risk Factor for Brain Damage in Preterm Newborns

The risk of oxidative stress is high in preterm newborns. Room air exposure of an organism primed to develop in a hypoxic environment, lacking antioxidant defenses, and subjected to hyperoxia, hypoxia, and ischemia challenges the newborn with oxidative stress production. Free radicals can be generated by a multitude of other mechanisms, such as glutamate excitotoxicity, excess free iron, inflammation, and immune reactions. Free radical-induced damage caused by oxidative stress appears to be the major candidate for the pathogenesis of most of the complications of prematurity, brain being especially at risk, with short to long-term consequences. We review the role of free radical oxidative damage to the newborn brain and propose a mechanism of oxidative injury, taking into consideration the particular maturation-dependent vulnerability of the oligodendrocyte precursors. Prompted by our observation of an increase in plasma Adenosine concentrations significantly associated with brain white matter lesions in some premature infants, we discuss a possible bioenergetics hypothesis, correlated to the oxidative challenge of the premature infant. We aim at explaining both the oxidative stress generation and the mechanism promoting the myelination disturbances. Being white matter abnormalities among the most common lesions of prematurity, the use of Adenosine as a biomarker of brain damage appears promising in order to design neuroprotective strategies.

Direct Bilirubin Levels and Risk of Metabolic Syndrome in Healthy Chinese Men

Background

Serum bilirubin is a potent endogenous antioxidant with anti-inflammatory properties. Several cross-sectional studies have reported that bilirubin was negatively associated with metabolic syndrome. However, in recent longitudinal studies, the relations between bilirubin and metabolic syndrome are inconsistent. Moreover, previous studies mainly focused on serum total bilirubin which is the sum of direct bilirubin and indirect bilirubin. For these reasons, the longitudinal effect of bilirubin subtypes on incident metabolic syndrome was evaluated in Chinese men.

Methods

The study cohort involved 1339 Chinese men without metabolic syndrome. Metabolic syndrome was defined by the American Heart Association/National Heart, Lung and Blood Institute (AHA/NHLBI) criteria, using BMI for the replacement of waist circumference.

Results

There are 117 incident metabolic syndrome cases (8.7%) during 5 years of follow-up among 1339 metabolic syndrome-free participants at baseline. After adjusting for age, drinking, smoking, physical activity, TG, and LDL-C, the odd ratios (ORs) and 95% confidence intervals (CIs) for MetS incidence in the second, third, and fourth quartiles versus the first quartile of DBil concentration were 1.00 (0.61-1.63), 0.57 (0.32-1.02), and 0.51 (0.28-0.92) (P_trend = 0.031), respectively.

Conclusions

Our findings support the negative association between direct bilirubin and incident metabolic syndrome in healthy Chinese men over 5-year period.

The Contribution of Oxidative Stress and Inflamm-Aging in Human and Equine Asthma

Aging is associated with a dysregulation of the immune system, leading to a general pro-inflammatory state of the organism, a process that has been named inflamm-aging. Oxidative stress has an important role in aging and in the regulation of immune responses, probably playing a role in the development of age-related diseases. The respiratory system function physiologically declines with the advancement of age. In elderly asthmatic patients, this may contribute to disease expression. In this review, we will focus on age-related changes affecting the immune system and in respiratory structure and function that could contribute to asthma occurrence, and/or clinical presentation in the elderly. Also, naturally occurring equine asthma will be discussed as a possible model for studying the importance of oxidative stress and immun-aging/inflamm-aging in humans.

The α-lipoic acid improves high-fat diet-induced cerebral damage through inhibition of oxidative stress and inflammatory reaction

This study is to clarify the protective role of α-lipoic acid in high-fat diet-induced cerebral damage mice. The mice were divided into 5 groups: normal control group, high-fat diet (HFD) group, low-dose α-lipoic acid group for prevention, high-dose α-lipoic acid group for prevention, and high-dose α-lipoic acid group for treatment. The groups' weights and blood glucose changes were monitored. We used HE staining to observe morphological changes in the cerebral cortex. The expression levels of the oxidative stress proteins SOD2, catalase, and the inflammatory pathway proteins p-JNK, p-ERK were measured by western blot and immunochemistry. Compared with the control group, the quantity of cortical neurons in the HFD group was decreased, and the samples exhibited retrogression. However, the lipoic acid significantly protected and promoted the cortical neurons survival. Moreover, compared with the HFD group, the expression levels of SOD2 and catalase in the three α-lipoic acid obtained groups were significantly increased. However, the expression levels of the inflammatory pathway proteins p-JNK and p-ERK were significantly decreased. These results indicate that theα-lipoic acid greatly protects the cortical neurons, and inhibited the oxidative stress and inflammatory reactions in the high-fat diet mice.

The Role of High-Mobility Group Box-1 and Its Crosstalk with Microbiome in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic, definitely disabling, and potentially severe autoimmune disease. Although an increasing number of patients are affected, a key treatment for all patients has not been discovered. High-mobility group box-1 (HMGB1) is a nuclear protein passively and actively released by almost all cell types after several stimuli. HMGB1 is involved in RA pathogenesis, but a convincing explanation about its role and possible modulation in RA is still lacking. Microbiome and its homeostasis are altered in patients with RA, and the microbiota restoration has been proposed to patients with RA. The purpose of the present review is to analyze the available evidences regarding HMGB1 and microbiome roles in RA and the possible implications of the crosstalk between the nuclear protein and microbiome in understanding and possibly treating patients affected by this harmful condition.

The Contribution of Singlet Oxygen to Insulin Resistance

Insulin resistance contributes to the development of diabetes and cardiovascular dysfunctions. Recent studies showed that elevated singlet oxygen-mediated lipid peroxidation precedes and predicts diet-induced insulin resistance (IR), and neutrophils were suggested to be responsible for such singlet oxygen production. This review highlights literature suggesting that insulin-responsive cells such as endothelial cells, hepatocytes, adipocytes, and myocytes also produce singlet oxygen, which contributes to insulin resistance, for example, by generating bioactive aldehydes, inducing endoplasmic reticulum (ER) stress, and modifying mitochondrial DNA. In these cells, nutrient overload leads to the activation of Toll-like receptor 4 and other receptors, leading to the production of both peroxynitrite and hydrogen peroxide, which react to produce singlet oxygen. Cytochrome P450 2E1 and cytochrome c also contribute to singlet oxygen formation in the ER and mitochondria, respectively. Endothelial cell-derived singlet oxygen is suggested to mediate the formation of oxidized low-density lipoprotein which perpetuates IR, partly through neutrophil recruitment to adipose tissue. New singlet oxygen-involving pathways for the formation of IR-inducing bioactive aldehydes such as 4-hydroperoxy-(or hydroxy or oxo)-2-nonenal, malondialdehyde, and cholesterol secosterol A are proposed. Strategies against IR should target the singlet oxygen-producing pathways, singlet oxygen quenching, and singlet oxygen-induced cellular responses.

Potential Role of L-Arginine and Vitamin E Against Bone Loss Induced by Nano-Zinc Oxide in Rats

The purpose of this study was to illustrate the effects of zinc oxide nanoparticles (ZnO-NPs) administration on bone turnover and bone resorbing agents in rats and how L-arginine (L-arg) or vitamin E (vit E) co-administrations might affect them. Fasting rats were randomly divided into four groups (n = 10): G1-normal healthy animals; G2-ZnO-NPs-exposed rats (600 mg/kg^-1/day^-1); G3-ZnO-NPs-exposed rats co-administrated L-arg (200 mg/kg^-1/day^-1); G4-ZnO-NPs-exposed rats co-administrated vit E (200 mg/kg^-1/day^-1). The ingredients were orally administered daily. The body weight and food consumption of rats were recorded during the administration period and the experiment continued for three consecutive weeks. The results demonstrated that ZnO-NPs administration induced bone loss in rats as manifested by reduced activity of bone alkaline phosphatase (B-ALP) and increased level of C-terminal peptide type I collagen (CTx). The increase of inflammatory markers, tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) by ZnO-NPs suggests that deleterious effects of ZnO-NPs on bone turnover were, in part, due to inflammation. Confirming to this suggestion, both L-arg and vit E reduced TNF-α and IL-6 levels and consequently decreased bone resorption as indicated by reduced serum CTx level. This study proved that ZnO-NPs can induce bone turnover, which may be reduced by L-arg or vit.E co-administration, partly by anti-inflammatory mechanism.

Hotspots of age-related protein degradation: the importance of neighboring residues for the formation of non-disulfide crosslinks derived from cysteine

Over time, the long-lived proteins that are present throughout the human body deteriorate. Typically, they become racemized, truncated, and covalently cross-linked. One reaction responsible for age-related protein cross-linking in the lens was elucidated recently and shown to involve spontaneous formation of dehydroalanine (DHA) intermediates from phosphoserine. Cys residues are another potential source of DHA, and evidence for this was found in many lens crystallins. In the human lens, some sites were more prone to forming non-disulfide covalent cross-links than others. Foremost among them was Cys5 in βA4 crystallin. The reason for this enhanced reactivity was investigated using peptides. Oxidation of Cys to cystine was a prerequisite for DHA formation, and DHA production was accelerated markedly by the presence of a Lys, one residue separated from Cys5. Modeling and direct investigation of the N-terminal sequence of βA4 crystallin, as well as a variety of homologous peptides, showed that the epsilon amino group of Lys can promote DHA production by nucleophilic attack on the alpha proton of cystine. Once a DHA residue was generated, it could form intermolecular cross-links with Lys and Cys. In the lens, the most abundant cross-link involved Cys5 of βA4 crystallin attached via a thioether bond to glutathione. These findings illustrate the potential of Cys and disulfide bonds to act as precursors for irreversible covalent cross-links and the role of nearby amino acids in creating 'hotpsots' for the spontaneous processes responsible for protein degradation in aged tissues.

NLRP3 expression and urinary HSP72 in relation to biomarkers of inflammation and oxidative stress in diabetic nephropathy patients

Diabetic nephropathy (DN) is one of the major causes of end-stage renal disease. Nod-like receptors nucleotide-binding domain and leucine-rich repeat pyrin-3 domain (NLRP3) inflammasome displays a considerable role in the chronic inflammatory state observed in diabetic patients. Urinary heat shock protein 72 (uHSP72) is a sensitive and specific biomarker for the early detection of acute kidney injury. The aim of this study was to evaluate NLRP3 relative gene expression, its correlation with inflammatory and oxidative stress markers, and to assess the value of uHSP72 in the early detection of DN in type 2 diabetic patients with different degrees of DN. Forty-five type 2 diabetic patients: 15 normoalbuminuric, 15 microalbuminuric, 15 macroalbuminuric, in addition to 15 healthy controls were enrolled in this study. Clinical examination and routine laboratory investigations were performed. NLRP3 mRNA expression was assessed by real time polymerase chain reaction. Serum 8-hydroxy-2'-deoxyguanosine (8-OHdG), interleukin 1β (IL-1β), and uHSP72 levels were estimated by enzyme-linked immunosorbent assay. Serum chitotriosidase (CHIT1) activity was examined. NLRP3 mRNA relative expression, serum levels of 8-OHdG, IL-1β, and uHSP72, in addition to CHIT 1 activity were significantly increased in the macroalbuminuric patient group as compared to control and the other two diabetic groups. Also, a significant positive correlation was documented between the previously mentioned parameters and urinary albumin/creatinine ratio, serum creatinine, and HbA1c. Multiple linear regression analysis using urinary albumin/creatinine ratio as dependent variable confirmed that uHSP72 and NLRP3 mRNA relative expression were the independent predictors of DN (β were 0.432 and 0.448 respectively, P < 0.001). Receiver operating characteristic analyses revealed that both NLRP3 mRNA relative expression and uHSP72 levels were useful biomarkers discriminating DN patients from patients with type 2 diabetes mellitus (AUC were 0.957 and 0.983, respectively). uHSP72 may be considered as a novel potential diagnostic biomarker for the early detection of DN. Moreover, these data support the pivotal role of NLRP3 in the development and progression of DN. © 2017 IUBMB Life, 69(8):623-630, 2017.

Pharmacological Reconditioning of Marginal Donor Rat Lungs Using Inhibitors of Peroxynitrite and Poly (ADP-ribose) Polymerase During Ex Vivo Lung Perfusion

BACKGROUND

Donor lungs obtained after prolonged warm ischemia (WI) may be unsuitable for transplantation due to the risk of reperfusion injury, but could be reconditioned using ex-vivo lung perfusion (EVLP). Key processes of reperfusion injury include the formation of reactive oxygen species (ROS)/nitrogen species (RNS) and the activation of poly(adenosine diphosphate-ribose) polymerase (PARP). We explored whether rat lungs obtained after WI could be reconditioned during EVLP using the ROS/RNS scavenger Mn(III)-tetrakis (4-benzoic acid) porphyrin chloride (MnTBAP) or the PARP inhibitor 3-aminobenzamide (3-AB).

METHODS

Rat lungs obtained after 3 hours cold ischemia (CI group, control), or 1 hour WI plus 2 hours CI (WI group) were placed in an EVLP circuit for normothermic perfusion for 3 hours. Lungs retrieved after WI were treated or not with 3-AB (1 mg/mL) or MnTBAP (0.3 mg/mL), added to the perfusate. Measurements included physiological variables (lung compliance, vascular resistance, oxygenation capacity), lung weight gain, levels of proteins, lactate dehydrogenase, protein carbonyl (marker of ROS), 3-nitrotyrosine (marker of RNS), poly(adenosine diphosphate-ribose) (PAR, marker of PARP activation) and IL-6, in the bronchoalveolar lavage or the lung tissue, and histology.

RESULTS

In comparison to the CI group, the lungs from the WI group displayed higher protein carbonyls, 3-nitrotyrosine, PAR, lactate dehydrogenase and proteins in bronchoalveolar lavage, lung weight gain, perivascular edema, as well as reduced static compliance, but similar oxygenation. All these alterations were markedly attenuated by 3-AB and MnTBAP.

CONCLUSIONS

After EVLP, lungs obtained after WI exhibit oxidative stress, PARP activation, and tissue injury, which are suppressed by pharmacological inhibitors of ROS/RNS and PARP.