Nitric oxide as a target of complementary and alternative medicines to prevent and treat inflammation and cancer

L-theanine alleviates myocardial ischemia/reperfusion injury by suppressing oxidative stress and apoptosis through activation of the JAK2/STAT3 pathway in mice

BACKGROUND

L-theanine is a unique non-protein amino acid in tea that is widely used as a safe food additive. We investigated the cardioprotective effects and mechanisms of L-theanine in myocardial ischemia-reperfusion injury (MIRI).

METHODS

The cardioprotective effects and mechanisms of L-theanine and the role of Janus Kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling were investigated in MIRI mice using measures of cardiac function, oxidative stress, and apoptosis.

RESULTS

Administration of L-theanine (10 mg/kg, once daily) suppressed the MIRI-induced increase in infarct size and serum creatine kinase and lactate dehydrogenase levels, as well as MIRI-induced cardiac apoptosis, as evidenced by an increase in Bcl-2 expression and a decrease in Bax/caspase-3 expression. Administration of L-theanine also decreased the levels of parameters reflecting oxidative stress, such as dihydroethidium, malondialdehyde, and nitric oxide, and increased the levels of parameters reflecting anti-oxidation, such as total antioxidant capacity (T-AOC), glutathione (GSH), and superoxide dismutase (SOD) in ischemic heart tissue. Further analysis showed that L-theanine administration suppressed the MIRI-induced decrease of phospho-JAK2 and phospho-STAT3 in ischemic heart tissue. Inhibition of JAK2 by AG490 (5 mg/kg, once daily) abolished the cardioprotective effect of L-theanine, suggesting that the JAK2/STAT3 signaling pathway may play an essential role in mediating the anti-I/R effect of L-theanine.

CONCLUSIONS

L-theanine administration suppresses cellular apoptosis and oxidative stress in part via the JAK2/STAT3 signaling pathway, thereby attenuating MIRI-induced cardiac injury. L-theanine could be developed as a potential drug to alleviate cardiac damage in MIRI.

Synthesis of cinnamoyl tethered indoline derivatives with anti-inflammatory and antioxidant activities

Aimed to improve the anti-inflammatory activities of natural antioxidant caffeic acid phenethyl ester, the thirty derivatives of cinnamoyl tethered indoline were synthesized. The structure-activity relationship indicated that the fragments of catechol and 5-Cl-indolinyl were beneficial for the higher dual-activities of antioxidant and anti-inflammation. The most potent compound 4b suppressed the secretions of inflammatory cytokines IL-6 and TNF-α, inhibited inducible nitric oxide synthase (iNOS) expression, upregulated the antioxidant gene HO-1 expression and antioxidant enzyme SOD level, and inhibited oxidative stress marker MDA level. Besides, 4b and its acetate prodrug 4'b could effectively attenuate paw edema more than CAPE. In regard to anti-inflammatory mechanism, 4b suppressed the NF-κB activation associated with phosphorylation of p65 subunit and degradation of IκBα. In summary, this study provided a new anti-inflammatory derivative 4b which was worthy of further research.

Spirulina platensis as a growth booster for broiler; Insights into their nutritional, molecular, immunohistopathological, and microbiota modulating effects

BACKGROUND

The present study is designed to assess the effect of adding various doses of Spirulina platensis (SP) on broiler chicken growth performance, gut health, antioxidant biomarkers, cecal microbiota, histopathology, and immunohistochemistry of inducible nitric oxide synthase (iNOS). 240 male Cobb 500 broiler chicks (1 day old) were placed into four groups (sixty birds/group), then each group was further divided into three replicates of 20 chickens each for 35 days. Birds were allocated as follows; the 1st group (G1), the control group, fed on basal diet, the 2nd group (G2): basal diet plus SP (0.1%), the 3rd group (G3): basal diet plus SP (0.3%), and the 4th group (G4): basal diet plus SP (0.5%).

RESULTS

Throughout the trial (d 1 to 35), SP fortification significantly increased body weight growth (BWG) and feed conversion rate (FCR) (P < 0.05). Bursa considerably increased among the immunological organs in the Spirulina-supplemented groups. Within SP-supplemented groups, there was a substantial increase in catalase activity, blood total antioxidant capacity, jejunal superoxide dismutase (SOD), and glutathione peroxidase (GPX) activity (P < 0.05). Fatty acid binding protein 2 (FABP2), one of the gut barrier health biomarkers, significantly increased in the SP-supplemented groups but the IL-1β gene did not significantly differ across the groups (P < 0.05). Different organs in the control group showed histopathological changes, while the SP-supplemented chicken showed fewer or no signs of these lesions. The control group had higher levels of iNOS expression in the gut than the SP-supplemented groups (p < 0.05). Cecal Lactobacillus count significantly elevated with increasing the rate of SP inclusion rate (p < 0.05).

CONCLUSION

Supplementing broiler diets with SP, particularly at 0.5%, can improve productivity and profitability by promoting weight increase, feed utilization, antioxidant status, immunity, and gastrointestinal health.

The Impact of ROS and NGF in the Gliomagenesis and their Emerging Implications in the Glioma Treatment

Reactive oxygen species (ROS) are highly reactive molecules derived from molecular oxygen (O2). ROS sources can be endogenous, such as cellular organelles and inflammatory cells, or exogenous, such as ionizing radiation, alcohol, food, tobacco, chemotherapeutical agents and infectious agents. Oxidative stress results in damage of several cellular structures (lipids, proteins, lipoproteins, and DNA) and is implicated in various disease states such as atherosclerosis, diabetes, cancer, neurodegeneration, and aging. A large body of studies showed that ROS plays an important role in carcinogenesis. Indeed, increased production of ROS causes accumulation in DNA damage leading to tumorigenesis. Various investigations demonstrated the involvement of ROS in gliomagenesis. The most common type of primary intracranial tumor in adults is represented by glioma. Furthermore, there is growing attention on the role of the Nerve Growth Factor (NGF) in brain tumor pathogenesis. NGF is a growth factor belonging to the family of neurotrophins. It is involved in neuronal differentiation, proliferation and survival. Studies were conducted to investigate NGF pathogenesis's role as a pro- or anti-tumoral factor in brain tumors. It has been observed that NGF can induce both differentiation and proliferation in cells. The involvement of NGF in the pathogenesis of brain tumors leads to the hypothesis of a possible implication of NGF in new therapeutic strategies. Recent studies have focused on the role of neurotrophin receptors as potential targets in glioma therapy. This review provides an updated overview of the role of ROS and NGF in gliomagenesis and their emerging role in glioma treatment.

Indole-3-Carbinol (I3C) Protects the Heart From Ischemia/Reperfusion Injury by Inhibiting Oxidative Stress, Inflammation, and Cellular Apoptosis in Mice

Strategies for treating myocardial ischemia in the clinic usually include re-canalization of the coronary arteries to restore blood supply to the myocardium. However, myocardial reperfusion insult often leads to oxidative stress and inflammation, which in turn leads to apoptosis and necrosis of myocardial cells, for which there are no standard treatment methods. The aim of this study was to determine the pharmacological effect of indole-3-carbinol (I3C), a phytochemical found in most cruciferous vegetables, in a mouse model of myocardial ischemia/reperfusion injury (MIRI). Our results showed that I3C pretreatment (100 mg/kg, once daily, i. p.) prevented the MIRI-induced increase in infarct size and serum creatine kinase (CK) and lactate dehydrogenase (LDH) in mice. I3C pretreatment also suppressed cardiac apoptosis in MIRI mice by increasing the expression levels of the anti-apoptotic protein Bcl-2 and decreasing the expression levels of several apoptotic proteins, including Bax, caspase-3, and caspase-9. In addition, I3C pretreatment was found to reduce the levels of parameters reflecting oxidative stress, such as dihydroethidium (DHE), malondialdehyde (MDA), reactive oxygen species (ROS), and nitric oxide (NO), while increasing the levels of parameters reflecting anti-oxidation, such as total antioxidant capacity (T-AOC) and glutathione (GSH), in MIRI-induced ischemic heart tissue. I3C pretreatment was also able to remarkably decrease the expression of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) mRNA in ischemic heart tissue. These results demonstrate that administration of I3C protects the heart from MIRI through its anti-apoptotic, antioxidant, and anti-inflammatory effects.

Single-Walled Carbon Nanotube-Based Biosensors for Detection of Bronchial Inflammation

Inflammation is a protective mechanism against invading pathogens and tissue damage. However, the inflammatory process is implicated in a wide range of diseases affecting all organs and body systems. Nitric oxide — a multifunctional signaling molecule that plays a critical role in systemic blood pressure homeostasis, prevention of platelet aggregation, antimicrobial resistance, immunoregulation, tumor suppression and as a neurotransmitter — is used as a surrogate marker for inflammation. However, the most commonly used Griess assay is an indirect and expensive method for the determination of nitric oxide concentration. Hence, single-walled carbon nanotube-based biosensors have been explored as real-time, sensitive, selective and safe methods to determine nitric oxide released during the inflammatory process. In this review, we explore current developments in single-walled carbon nanotube-based biosensors for the detection of nitric oxide in exhaled breath as a direct and noninvasive test for detection of bronchial inflammation.

Single-Walled Carbon Nanotube Sensor Platform for the Study of Extracellular Analytes

Single-walled carbon nanotubes (SWNT) are attractive targets for the formation of high-density sensor arrays. Their small size and high reactivity could allow for the spatial and temporal study of extracellular products to a degree which greatly surpasses contemporary sensors. However, current methods of SWNT immobilization produce a low fluorescence yield that requires a combination of high magnification, exposure time, and laser intensity to combat, thus limiting the sensor's applications. In this work, a platform for the immobilization of SWNT sensors with increased fluorescence yield, longevity, fluorescence distribution, and fast reaction times is developed.

9‑Hydroxy‑isoegomaketone inhibits LPS‑induced NO and inflammatory cytokine production in RAW264.7 cells

Isoegomaketone (IK) is a known component of Perilla frutescens that reportedly exhibits anti-inflammatory, anti-cancer and anti-allergic properties. A novel compound known as 9-HIK has been isolated from the extract of a radiation mutant P. frutescens var. crispa using supercritical carbon dioxide. In the present study, 9-HIK induced heme oxygenase-1 (HO-1) mRNA expression in RAW264.7 cells, with maximal levels observed 4 h after 9-HIK treatment. In addition, 9-HIK inhibited the mRNA and protein expression of pro-inflammatory mediators, such as IL-6 and interferon-β, as well as the production of nitric oxide (NO) in lipopolysaccharide-stimulated RAW264.7 cells. Furthermore, N-acetyl-L-cysteine, a reactive oxygen species scavenger, inhibited NO production and HO-1 mRNA expression levels through the nuclear factor erythroid 2-related factor 2 pathway. Overall, 9-HIK displayed anti-inflammatory properties in LPS-induced RAW264.7 cells via direct suppression of inflammatory mediators and HO-1 induction.

Synthesis and biological evaluation of (1,2,4)triazole[4,3-a]pyridine derivatives as potential therapeutic agents for concanavalin A-induced hepatitis

A series of (1,2,4)triazole[4,3-a]pyridine (TZP) derivatives have been designed and synthesized. Compound 8d was identified as having the most potent inhibitory activity on NO release in response to lipopolysaccharide (LPS) stimulation and inhibition of the migration induced by MCP-1 protein on RAW264.7 macrophages. Based on the screening data, an immunofluorescence assay and a real-time qPCR assay were conducted, indicating that compound 8d suppressed NF-κB p65 translocation and expression of inflammatory genes by concanavalin A (Con A)-induced RAW264.7 macrophages. More importantly, 8d also exhibited potent efficacy, alleviating Con A-induced hepatitis by downregulating the levels of plasma alanine transaminase (ALT), aspartate transaminase (AST) and inflammatory infiltration in a mouse autoimmune hepatitis (AIH) model. In addition, the flow cytometry (FCM) data showed that compound 8d inhibited the accumulation of MDSCs in the liver of Con A-induced mice. These findings raise the possibility that compound 8d might serve as a potential agent for the treatment of AIH.

2'-Hydroxy-5'-methoxyacetophenone attenuates the inflammatory response in LPS-induced BV-2 and RAW264.7 cells via NF-κB signaling pathway

Seahorse has been used as a traditional medicine in Southeast Asian countries for a long time. A compound, 2'-Hydroxy-5'-Methoxyacetophenone (2H5M) isolated from seahorse, Hippocampus kuda, was tested for its anti-inflammatory effect in lipopolysaccharides (LPS)-stimulated BV-2 cells and RAW264.7 cells. MTT assay indicated that 2H5M has no cytotoxicity on two kinds of cells. The concentration of nitric oxide (NO) measured by Griess Reaction System showed that 2H5M could significantly inhibit the NO concentration. The ELISA results showed that 2H5M could suppress the secretion of TNF-α in a dose-dependent manner. Moreover, western blot analysis was utilized to measure the protein levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) signaling pathways. Electrophoretic mobility shift assay (EMSA) demonstrated that 2H5M reduced NF-κB DNA binding activity. Furthermore, the molecular docking study showed that 2H5M can form active sites with NF-κB. Collectively, these results indicated that 2H5M possesses anti-inflammatory effects and may have a potential application in inflammatory disorders in the future.

Bioactive Secondary Metabolites from Octocoral-Associated Microbes-New Chances for Blue Growth

Octocorals (Cnidaria, Anthozoa Octocorallia) are magnificent repositories of natural products with fascinating and unusual chemical structures and bioactivities of interest to medicine and biotechnology. However, mechanistic understanding of the contribution of microbial symbionts to the chemical diversity of octocorals is yet to be achieved. This review inventories the natural products so-far described for octocoral-derived bacteria and fungi, uncovering a true chemical arsenal of terpenes, steroids, alkaloids, and polyketides with antibacterial, antifungal, antiviral, antifouling, anticancer, anti-inflammatory, and antimalarial activities of enormous potential for blue growth. Genome mining of 15 bacterial associates (spanning 12 genera) cultivated from Eunicella spp. resulted in the identification of 440 putative and classifiable secondary metabolite biosynthetic gene clusters (BGCs), encompassing varied terpene-, polyketide-, bacteriocin-, and nonribosomal peptide-synthase BGCs. This points towards a widespread yet uncharted capacity of octocoral-associated bacteria to synthetize a broad range of natural products. However, to extend our knowledge and foster the near-future laboratory production of bioactive compounds from (cultivatable and currently uncultivatable) octocoral symbionts, optimal blending between targeted metagenomics, DNA recombinant technologies, improved symbiont cultivation, functional genomics, and analytical chemistry are required. Such a multidisciplinary undertaking is key to achieving a sustainable response to the urgent industrial demand for novel drugs and enzyme varieties.

Transcriptome analysis reveals the role of nitric oxide in Pleurotus eryngii responses to Cd2+ stress

Pleurotus eryngii is widely cultivated in China. However, our understanding of its transcriptional response to heavy metal stress and the underlying mechanism of nitric oxide (NO) in enhancing its tolerance to heavy metals is limited. In the present study, RNA-seq was used to generate large transcript sequences from P. eryngii exposed to cadmium chloride (CdCl₂) and exogenous NO. A total of 45,833 unigenes were assembled from the P. eryngii transcriptome, of which 32,333 (70.54%) unigenes matched known proteins in the nr database. Transcriptional analysis revealed that putative genes encoding heat shock proteins (HSPs) and genes participating in glycerolipid metabolism and steroid biosynthesis were significantly up-regulated in P. eryngii exposed to 50 μM Cd (P < 0.05). P. eryngii mycelia exposed to extremely high levels of heavy metals showed an increase in biomass when exogenous NO was added to the culture. The collaboration of putative oxidoreductase, dehydrogenase, reductase, transferase genes and transcription factors such as "GTPase activator activity", "transcription factor complex", "ATP binding", "GTP binding", and "enzyme activator activity", which were significantly up-regulated in samples induced by exogenous NO, contributed to the enhancement of P. eryngii tolerance to extremely high levels of heavy metals. The study provides a new insight into the transcriptional response of P. eryngii to extremely high levels of heavy metals and the mechanism of NO in enhancing heavy metal tolerance.

Anti-inflammatory effect of diterpenes-enriched fractions from Pterodon polygalaeflorus through inhibition of macrophage migration and cytokine production

Objectives

To evaluate the anti-inflammatory potential of Pterodon polygalaeflorus hexane extract (HE) and its fractions on macrophage migration in vitro and in vivo.

Methods

Hexane extract from P. polygalaeflorus fruits was fractionated and yielded four fractions. RAW 264.7 cells were treated with samples to evaluate cell viability (MTT assay), cell migration (wound healing and transwell assays), CD14 expression (flow cytometry), iNOS and cytokine mRNA expression (RT-qPCR), NO (Griess reaction) and cytokine (ELISA) production. In vivo migration was evaluated on the thioglycollate-induced peritonitis model. Qualitative analysis was performed by GC-MS.

Key findings

All fractions inhibited the NO production by LPS-stimulated RAW 264.7 cells. Fr3 and Fr4 presented the lowest IC50 values. The expressions of iNOS and IL-1β, TNF-α and IL-10 cytokines were inhibited by Fr3 and Fr4, whereas the CD14 expression was only inhibited by Fr3. All the samples inhibited RAW 264.7 migration in the wound healing and transwell assays. Fr3 and Fr4 reduced the migration of Mac-1+Gr-1− cells to the peritoneum and presented in their compositions: 6α-hydroxy-7β-acetoxyvouacapan-17β-oate, methyl 6α,7β-dihydroxyvouacapan-17β-oate, methyl 6α-acetoxy-7β-hydroxyvouacapan-17β-oate, geranylgeraniol and 14,15-epoxy-geranylgeraniol.

Conclusions

The anti-inflammatory effects of Fr3 and Fr4 involve inhibition of cell migration, iNOS expression and NO production, cytokine expression (mRNA and proteins) and CD14 expression (Fr3).

Hollow double-layered polymer nanoparticles with S-nitrosothiols for tumor targeted therapy

Tumor targeted hollow double-layered polymer nanoparticles (HDPNs) withS-nitrosothiols for nitric oxide (NO)-release as chemotherapy were described.

Antioxidant activities of Indigofera cassioides Rottl. Ex. DC. using various in vitro assay models

OBJECTIVE

To evaluate the antioxidant potential of methanolic leaf extract of Indigofera cassioides (MEIC) using various in vitro antioxidant assay systems.

METHODS

Antioxidant and free radical scavenging activity of MEIC was assayed by using different in vitro models like ABTS, DPPH, nitric oxide, superoxide, hydrogen peroxide and hydroxyl radical. Reductive ability of the extract was tested by the complex formation with potassium ferricyanide. Further total phenol and flavonoid contents of the crude extract were also determined. Rutin and ascorbic acid were used as standards.

RESULTS

MEIC exhibited potent and concentration dependent free radical scavenging activity in all the tested models. Reductive ability was also found to increase with increase in MEIC concentration. Total phenol and flavonoid content determination showed that the extract is rich in phenols and flavonoids.

CONCLUSIONS

All the results of the in vitro antioxidant assays reveal potent antioxidant and free radical scavenging activity of the leaves of Indigofera cassioides, equivalent to that of standard ascorbic acid and rutin. This potent antioxidant activity may be attributed to its high phenolic and flavonoid contents.

Sodium Butyrate Ameliorates L-Arginine-Induced Pancreatitis and Associated Fibrosis in Wistar Rat: Role of Inflammation and Nitrosative Stress

Several reports indicated that histone deacetylases (HDACs) play a crucial role in inflammation and fibrogenesis. Sodium butyrate (SB) is a short-chain fatty acid having HDAC inhibition potential. The present study aimed to evaluate the protective effect of SB against L-arginine (L-Arg)-induced pancreatic fibrosis in Wistar rats. Pancreatic fibrosis was induced by twice intraperitoneal (i.p.) injections of 20% L-Arg (250 mg/100 g) at 2-h interval on day 1, 4, 7, and 10, whereas SB (800 mg/kg/day) was administrated for 10 days. At the end of the study, biochemical estimations, histological alterations, DNA damage, and the expression of various proteins were evaluated. Posttreatment of SB decreased L-Arg-induced oxidative and nitrosative stress, DNA damage, histological alterations, and fibrosis. Interestingly, posttreatment of SB significantly decreased the expression of α-smooth muscle actin, interleukin-1β, inducible nitric oxide synthase, and 3-nitrotyrosine. The present study demonstrated that posttreatment of SB alleviates L-Arg-induced pancreatic damage and fibrosis in rat.

The role of nitric oxide and oxidative stress in intestinal damage induced by selenium deficiency in chickens

Nitric oxide (NO) is an essential messenger molecule and is associated with inflammation and oxidative stress. Although NO has important biological functions in mammals, its role in the mechanism that occurs after intestinal injuries in chickens remains unknown. The objective of the present study was to investigate the real role of NO and oxidative stress in the intestinal injuries of chickens induced by selenium (Se) deficiency. A total 150 chickens were randomly divided into the following two groups: a low-Se group (L group, fed a Se-deficient diet containing 0.020 mg/kg Se) and a control group (C group, fed a commercial diet containing 0.2 mg/kg Se). The activities and mRNA levels of glutathione peroxidase (GSH-Px), the production of glutathione (GSH) and NO, and the protein and mRNA levels of inducible nitric oxide synthase (iNOS) were examined in the intestinal tissues (duodenum, jejunum, and rectum) at 15, 25, 35, 45, and 55 days. Methane dicarboxylic aldehyde (MDA) levels were also detected by assay kits. Then, the morphologies of the tissues were observed under the microscope after hematoxylin and eosin staining (H&E staining). The results showed that Se deficiency induced higher inflammatory damage and MDA levels (P < 0.05), which were accompanied by higher levels of iNOS and NO but lower levels of GSH and GSH-Px (P < 0.05). Our results indicated that Se deficiency induced oxidative damage in the intestinal tracts of chickens and that low levels of GSH-Px and high contents of NO may exert a major role in the injury of the intestinal tract induced by Se deficiency.

Silica/polymer microspheres and hollow polymer microspheres as scaffolds for nitric oxide release in PBS buffer and bovine serum

SiO₂/P(AmEMA-co-EGDMA) core–shell microspheres and hollow P(AmEMA-co-EGDMA) nanospheres are prepared as NO donors.

Bioactivity of Fragaria vesca leaves through inflammation, proteasome and autophagy modulation

ETHNOPHARMACOLOGICAL RELEVANCE

Fragaria vesca leaves have been used in folk medicine for the treatment of several diseases, namely gastrointestinal, cardiovascular and urinary disorders, which could be related with the potential anti-inflammatory properties of the extract. This work aims to disclose the bioactivity and the underlying action mechanism of an extract from Fragaria vesca leaves in order to support its traditional uses.

MATERIALS AND METHODS

A hydroalcoholic extract was prepared from Fragaria vesca leaves and its anti-inflammatory potential was evaluated through inhibition of nitric oxide production and expression of several pro-inflammatory proteins in lipopolysaccharide-triggered macrophages. Nitric oxide scavenger activity was also assessed using a standard nitric oxide donor. Since numerous inflammatory proteins are tightly regulated by ubiquitination and proteasomal degradation, the putative effect of the extract on these cellular proteolytic pathways was also disclosed. The phytochemical characterization was performed by HPLC-PDA-ESI/MSn and compared with an infusion prepared according to the traditional method.

RESULTS

For non-cytotoxic concentrations (80 and 160µg/mL) the extract inhibited nitrite production, probably due to a direct nitric oxide scavenging. Furthermore, inhibition of proteasome activity was verified, leading to accumulation of ubiquitinated proteins. The extract also increased the conversion of the microtubule-associated protein light chain LC3-I to LC3-II, a marker of autophagy. Polyphenols, namely ellagitannins, proanthocyanidins, and quercetin and kaempferol glucuronide derivatives were identified in Fragaria vesca leaves extract. Most of the identified phenolic compounds matched with those found in traditional preparation, the infusion.

CONCLUSIONS

The extract has a direct nitric oxide scavenging activity giving support to the traditional use of this plant for the treatment of inflammatory disorders. Furthermore, the extract affects the proteolytic systems but its role in cancer treatment requires further studies.

Oxidative damage in the progression of chronic liver disease to hepatocellular carcinoma: An intricate pathway

The histo-pathologic and molecular mechanisms leading to initiation and progression of hepatocellular carcinoma (HCC) are still ill-defined; however, there is increasing evidence that the gradual accumulation of mutations, genetic and epigenetic changes which occur in preneoplastic hepatocytes results in the development of dysplastic foci, nodules, and finally, overt HCC. As well as many other neoplasias, liver cancer is considered an “inflammatory cancer”, arising from a context of inflammation, and characterized by inflammation-related mechanisms that favor tumor cell survival, proliferation, and invasion. Molecular mechanisms that link inflammation and neoplasia have been widely investigated, and it has been well established that inflammatory cells recruited at these sites with ongoing inflammatory activity release chemokines that enhance the production of reactive oxygen species. The latter, in turn, probably have a major pathogenic role in the continuum starting from hepatitis followed by chronic inflammation, and ultimately leading to cancer. The relationship amongst chronic liver injury, free radical production, and development of HCC is explored in the present review, particularly in the light of the complex network that involves oxidative DNA damage, cytokine synthesis, telomere dysfunction, and microRNA regulation.

Evaluation of antioxidant and antiangiogenic properties of caesalpinia echinata extracts

Natural products contain important combinations of ingredients, which may to some extent help to modulate the effects produced by oxidation substrates in biological systems. It is known that substances capable of modulating the action of these oxidants on tissue may be important allies in the control of neovascularization in pathological processes. The aim of this study was to evaluate the antioxidant and antiangiogenic properties of an ethanol extract of Caesalpinia echinata. The evaluation of antioxidant properties was tested using two methods (DPPH inhibition and sequestration of nitric oxide). The antiangiogenic properties were evaluated using the inflammatory angiogenesis model in the corneas of rats. The extract of C. echinata demonstrated a high capacity to inhibit free radicals, with IC50 equal to 42.404 µg/mL for the DPPH test and 234.2 µg/mL for nitric oxide. Moreover, it showed itself capable of inhibiting the inflammatory angiogenic response by 77.49%. These data suggest that biochemical components belonging to the extract of C. echinata interfere in mechanisms that control the angiogenic process, mediated by substrates belonging to the arachidonic acid cascade, although the data described above also suggest that the NO buffer may contribute to some extent to the reduction in the angiogenic response.

Synthesis of 2-arylindole derivatives and evaluation as nitric oxide synthase and NFκB inhibitors

Development of small molecule drug-like inhibitors blocking both nitric oxide synthase and NFκB could offer a synergistic therapeutic approach in the prevention and treatment of inflammation and cancer. During the course of evaluating the biological potential of a commercial compound library, 2-phenylindole (1) displayed inhibitory activity against nitrite production and NFκB with IC(50) values of 38.1 ± 1.8 and 25.4 ± 2.1 μM, respectively. Based on this lead, synthesis and systematic optimization have been undertaken in an effort to find novel and more potent nitric oxide synthase and NFκB inhibitors with antiinflammatory and cancer preventive potential. First, chemical derivatizations of 1 and 2-phenylindole-3-carboxaldehyde (4) were performed to generate a panel of N-alkylated indoles and 3-oxime derivatives 2–7. Second, a series of diversified 2-arylindole derivatives (10) were synthesized from an array of substituted 2-iodoanilines (8) and terminal alkynes (9) by applying a one-pot palladium catalyzed Sonogashira-type alkynylation and base-assisted cycloaddition. Subsequent biological evaluations revealed 3-carboxaldehyde oxime and cyano substituted 2-phenylindoles 5 and 7 exhibited the strongest nitrite inhibitory activities (IC(50) = 4.4 ± 0.5 and 4.8 ± 0.4 μM, respectively); as well as NFκB inhibition (IC(50) = 6.9 ± 0.8 and 8.5 ± 2.0 μM, respectively). In addition, the 6′-MeO-naphthalen-2′-yl indole derivative 10at displayed excellent inhibitory activity against NFκB with an IC(50) value of 0.6 ± 0.2 μM.

The role of inflammation and proteinases in tumor progression

Chronic inflammation is an important risk factor for the development of cancers. The link between chronic inflammation and the risk of developing cancer is now well established. At least 20% of all cancers arise in association with infection and chronic inflammation. Inflammation and cancer are linked both along intrinsic (driven by genetic events causing malignancy) and extrinsic (driven by inflammatory conditions predisposing to tumor) pathways. Proteinases are key contributors to the breakdown and reconstitution of extracellular matrix components in physiological processes and pathological conditions, including destructive diseases and tumor progression. Matrix metalloproteinases are especially essential in the complex process of coregulation between cellular components of the tumor environment, and they are considered as potential diagnostic and prognostic biomarkers in many types and stages of cancer. Although the link between chronic inflammation, proteinases and risk of developing cancer is now well established, several open questions remain. The most exciting challenge is to find the best approach to target cancer-associated inflammation in patients with cancer. With respect to matrix metalloproteinases, the development of a new generation of selective inhibitors is a promising area of research.

BDMC33, A curcumin derivative suppresses inflammatory responses in macrophage-like cellular system: role of inhibition in NF-κB and MAPK signaling pathways

Our preliminary screening has shown that curcumin derivative BDMC33 [2,6-bis(2,5-dimethoxybenzylidene)cyclohexanone] exerted promising nitric oxide inhibitory activity in activated macrophages. However, the molecular basis and mechanism for its pharmacological action is yet to be elucidated. The aim of this study was to investigate the anti-inflammatory properties of BDMC33 and elucidate its underlying mechanism action in macrophage cells. Our current study demonstrated that BDMC33 inhibits the secretion of major pro-inflammatory mediators in stimulated macrophages, and includes NO, TNF-α and IL-1β through interference in both nuclear factor kappaB (NF-κB) and mitogen activator protein kinase (MAPK) signaling cascade in IFN-γ/LPS-stimulated macrophages. Moreover, BDMC33 also interrupted LPS signaling through inhibiting the surface expression of CD-14 accessory molecules. In addition, the inhibitory action of BDMC33 not only restricted the macrophages cell (RAW264.7), but also inhibited the secretion of NO and TNF-α in IFN-γ/LPS-challenged microglial cells (BV-2). The experimental data suggests the inflammatory action of BDMC33 on activated macrophage-like cellular systems, which could be used as a future therapeutic agent in the management of chronic inflammatory diseases.

Mechanisms of anti-cancer effects of plant polyphenols II. Suppression on tumor growth

Mechanisms of suppression of carcinogenesis promotion/progression by plant polyphenols have been considered. They can decrease cyclins and cycline dependent kinases and activate inhibitor proteins in tumor cells that results in cell cycle arrest. Plant polyphenols can induce apoptosis by modulating anti/proapoptotic proteins and also can inhibit tumor metastasis and angiogenesis. Polyphenols act through the regulation of cell signal transduction and gene expression.

Role of TLR2-dependent inflammation in metastatic progression

Inflammation is a part of the host defense system, which provides protection against invading pathogens. However, it has become increasingly clear that inflammation can be evoked by endogenous mediators through Toll-like receptors (TLRs) to enhance tumor progression and metastasis. Here, we discuss the roles of TLR-mediated inflammation in tumor progression and the mechanisms through which it accomplishes this pathogenic function.

Single molecule detection of nitric oxide enabled by d(AT)15 DNA adsorbed to near infrared fluorescent single-walled carbon nanotubes

We report the selective detection of single nitric oxide (NO) molecules using a specific DNA sequence of d(AT)(15) oligonucleotides, adsorbed to an array of near-infrared fluorescent semiconducting single-walled carbon nanotubes (AT(15)-SWNT). While SWNT suspended with eight other variant DNA sequences show fluorescence quenching or enhancement from analytes such as dopamine, NADH, L-ascorbic acid, and riboflavin, d(AT)(15) imparts SWNT with a distinct selectivity toward NO. In contrast, the electrostatically neutral polyvinyl alcohol enables no response to nitric oxide, but exhibits fluorescent enhancement to other molecules in the tested library. For AT(15)-SWNT, a stepwise fluorescence decrease is observed when the nanotubes are exposed to NO, reporting the dynamics of single-molecule NO adsorption via SWNT exciton quenching. We describe these quenching traces using a birth-and-death Markov model, and the maximum likelihood estimator of adsorption and desorption rates of NO is derived. Applying the method to simulated traces indicates that the resulting error in the estimated rate constants is less than 5% under our experimental conditions, allowing for calibration using a series of NO concentrations. As expected, the adsorption rate is found to be linearly proportional to NO concentration, and the intrinsic single-site NO adsorption rate constant is 0.001 s(-1) μM NO(-1). The ability to detect nitric oxide quantitatively at the single-molecule level may find applications in new cellular assays for the study of nitric oxide carcinogenesis and chemical signaling, as well as medical diagnostics for inflammation.

Anti-inflammatory activity of Cymbopogon citratus leaf infusion in lipopolysaccharide-stimulated dendritic cells: contribution of the polyphenols

Cymbopogon citratus, an herb known worldwide as lemongrass, is widely consumed as an aromatic drink, and its fresh and dried leaves are currently used in traditional cuisine. However, little is known about the mechanism of action of C. citratus, namely, the anti-inflammatory effects of its dietary components. Because nitric oxide (NO), produced in large quantities by activated inflammatory cells, has been demonstrated to be involved in the pathogenesis of acute and chronic inflammation, we evaluated the effects of the infusion of dried leaves from C. citratus, as well as its polyphenolic fractions--flavonoid-, tannin-, and phenolic acid-rich fractions (FF, TF, and PAF, respectively)--on the NO production induced by lipopolysaccharide (LPS) in a skin-derived dendritic cell line (FSDC). C. citratus infusion significantly inhibited the LPS-induced NO production and inducible NO synthase (iNOS) protein expression. All the polyphenolic fractions tested also reduced the iNOS protein levels and NO production stimulated by LPS in FSDC cells, without affecting cell viability, with the strongest effects being observed for the fractions with mono- and polymeric flavonoids (FF and TF, respectively). Our results also indicated that the anti-inflammatory properties of FF are mainly due to luteolin glycosides. In conclusion, C. citratus has NO scavenging activity and inhibits iNOS expression and should be explored for the treatment of inflammatory diseases, in particular of the gastrointestinal tract.

Food contaminant acrylamide increases expression of Cox-2 and nitric oxide synthase in breast epithelial cells

Acrylamide has been discovered in foods cooked at high temperature. A potentially harmful effect of this dietary component has been suggested by data indicating its association with increased breast cancer. This study investigated the potential effects of acrylamide in nontumorigenic breast cells by assessing expression levels of inducible nitric oxide synthase (iNOS) and cycloogenase-2 (Cox-2) and NOS activity, which are known to be early molecular changes in disease formation. Treatment of cells with acrylamide increased levels of iNOS (both expression and activity) and Cox-2. Its potent metabolite, glycidamide, also induced both iNOS and Cox-2, with induction of iNOS occurring at a lower concentration. 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), another food-borne carcinogen, was found to induce Cox-2 expression. Combining acrylamide with PhIP did not result in a further increase. These studies suggest that further research is needed to determine the role of carcinogens formed from cooking foods in inducing early molecular changes associated with breast cancer.

Essential oils from Distichoselinum tenuifolium: chemical composition, cytotoxicity, antifungal and anti-inflammatory properties

ETHNOPHARMACOLOGICAL RELEVANCE

Several aromatic plants and their essential oils are known to possess antimicrobial and anti-inflammatory properties. Distichoselinum tenuifolium (Lag.) Garcia Martin & Silvestre, an Iberian endemism, is traditionally used in the treatment of contact dermatitis and skin infections. However, the cellular mechanisms through which this plant exerts their beneficial effects are not known.

AIM OF THE STUDY

The aims of this study were to examine the chemical composition of the essential oil isolated from Distichoselinum tenuifolium, and to test the efficacy of the essential oil as an antifungal and anti-inflammatory potential.

MATERIALS AND METHODS

The oils were investigated by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) and the antifungal activity (minimal inhibitory concentrations: MIC and minimal lethal concentrations: MLC) were evaluated against yeasts, dermatophyte and Aspergillus strains. Assessment of cell viability was made by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and the in vitro anti-inflammatory potential of Distichoselinum tenuifolium oil was evaluated by measuring nitric oxide (NO) production induced by LPS, in the absence or in the presence of the oil, in a mouse macrophage cell line.

RESULTS

The oils are predominantly composed of monoterpene hydrocarbons, being myrcene the main compound (47.7-84.6%). The oils revealed significant antifungal activity against Cryptococcus neoformans and dermatophyte strains and significantly inhibited NO production stimulated by LPS in macrophages, without affecting cell viability at concentrations ranging from 0.64 microL/mL to 1.25 microL/mL.

CONCLUSION

These findings add significant information to the pharmacological activity of Distichoselinum tenuifolium essential oils, specifically to its antifungal and anti-inflammatory properties, thus justifying and reinforcing the use of this plant on traditional medicine. Therefore, their beneficial effects and use in disease prevention, especially those related to fungal infections and inflammation, should be explored in more depth.

Role of inflammation and oxidative stress mediators in gliomas

Gliomas are the most common primary brain tumors of the central nervous system. Despite relevant progress in conventional treatments, the prognosis of such tumors remains almost invariably dismal. The genesis of gliomas is a complex, multistep process that includes cellular neoplastic transformation, resistance to apoptosis, loss of control of the cell cycle, angiogenesis, and the acquisition of invasive properties. Among a number of different biomolecular events, the existence of molecular connections between inflammation and oxidative stress pathways and the development of this cancer has been demonstrated. In particular, the tumor microenvironment, which is largely orchestrated by inflammatory molecules, is an indispensable participant in the neoplastic process, promoting proliferation, survival and migration of such tumors. Proinflammatory cytokines, such as tumor necrosis factor-alpha, interleukin-1beta, and interferon-gamma, as well as chemokines and prostaglandins, are synthesized by resident brain cells and lymphocytes invading the affected brain tissue. Key mediators of cancer progression include nuclear factor-kappaB, reactive oxygen and nitrogen species, and specific microRNAs. The collective activity of these mediators is largely responsible for a pro-tumorigenic response through changes in cell proliferation, cell death, cellular senescence, DNA mutation rates, DNA methylation and angiogenesis. We provide a general overview of the connection between specific inflammation and oxidative stress pathway molecules and gliomas. The elucidation of specific effects and interactions of these factors may provide the opportunity for the identification of new target molecules leading to improved diagnosis and treatment.

Suppression of inflammatory mediators by cruciferous vegetable-derived indole-3-carbinol and phenylethyl isothiocyanate in lipopolysaccharide-activated macrophages

This study was aimed to examine the effects of indole-3-carbinol (I3C) and beta-phenylethyl isothiocyanate (PEITC), bioactive components present in cruciferous vegetable, on the production of inflammatory mediators, including nitric oxide (NO), tumor necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10), in lipopolysaccharide- (LPS-) stimulated RAW 264.7 macrophages. Possible mechanisms of the NO-inhibitory effects were also explored. The results indicated that I3C and PEITC inhibited NO production, and this suppression was associated with decreased production of TNF-alpha and IL-10 by activated macrophages. In addition, I3C suppressed NO production even after the inducible nitric oxide synthase (iNOS) protein had been produced, but such an inhibitory effect was not observed in cells treated with PEITC. Furthermore, both compounds reduced the NO contents generated from an NO donor in a cell-free condition, suggesting that the increased NO clearance may have contributed to the NO-inhibitory effects. In summary, both I3C and PEITC possessed antiinflammatory effects by inhibiting the productions of NO, TNF-alpha, and IL-10, although the NO-inhibitory effects may have involved in different mechanisms.

American ginseng suppresses colitis through p53-mediated apoptosis of inflammatory cells

Ulcerative colitis is a dynamic, chronic inflammatory condition associated with an increased colon cancer risk. Inflammatory cell apoptosis is a key mechanism regulating ulcerative colitis. American ginseng (AG) is a putative antioxidant that can suppress hyperactive immune cells. We have recently shown that AG can prevent and treat mouse colitis. Because p53 levels are elevated in inflammatory cells in both mouse and human colitis, we tested the hypothesis that AG protects from colitis by driving inflammatory cell apoptosis through a p53 mechanism. We used isogenic p53(+/+) and p53(-/-) inflammatory cell lines as well as primary CD4(+)/CD25(-) effector T cells from p53(+/+) and p53(-/-) mice to show that AG drives apoptosis in a p53-dependent manner. Moreover, we used a dextran sulfate sodium (DSS) model of colitis in C57BL/6 p53(+/+) and p53(-/-) mice to test whether the protective effect of AG against colitis is p53 dependent. Data indicate that AG induces apoptosis in p53(+/+) but not in isogenic p53(-/-) cells in vitro. In vivo, C57BL/6 p53(+/+) mice are responsive to the protective effects of AG against DSS-induced colitis, whereas AG fails to protect from colitis in p53(-/-) mice. Furthermore, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling of inflammatory cells within the colonic mesenteric lymph nodes is elevated in p53(+/+) mice consuming DSS + AG but not in p53(-/-) mice consuming DSS + AG. Results are consistent with our in vitro data and with the hypothesis that AG drives inflammatory cell apoptosis in vivo, providing a mechanism by which AG protects from colitis in this DSS mouse model.

Inflammation and cancer: interweaving microRNA, free radical, cytokine and p53 pathways

Chronic inflammation and infection are major causes of cancer. There are continued improvements to our understanding of the molecular connections between inflammation and cancer. Key mediators of inflammation-induced cancer include nuclear factor kappa B, reactive oxygen and nitrogen species, inflammatory cytokines, prostaglandins and specific microRNAs. The collective activity of these mediators is largely responsible for either a pro-tumorigenic or anti-tumorigenic inflammatory response through changes in cell proliferation, cell death, cellular senescence, DNA mutation rates, DNA methylation and angiogenesis. As our understanding grows, inflammatory mediators will provide opportunities to develop novel diagnostic and therapeutic strategies. In this review, we provide a general overview of the connection between inflammation, microRNAs and cancer and highlight how our improved understanding of these connections may provide novel preventive, diagnostic and therapeutic strategies to reduce the health burden of cancer.

Bioactive components of tea: cancer, inflammation and behavior

Tea is one of the most widely consumed beverages worldwide. Several studies have suggested that catechins and theaflavins found in tea may reduce the risk of various types of cancers. Major advances have been made to understand the molecular events leading to cancer prevention; however, the evidence is not conclusive. Evidence from pre-clinical and clinical studies also suggests that persistent inflammation can progress to cancer. Several possible mechanisms of action may explain the cancer preventive aspects of tea components specifically anti-inflammatory effects. In regards to brain health, green tea catechins have been recognized as multifunctional compounds for neuroprotection with beneficial effects on vascular function and mental performance. Theanine, a unique amino acid in tea, enhances cognition in humans and has neuroprotective effects. Human interventional studies with well characterized tea products are needed.

The role of metallothionein in oncogenesis and cancer prognosis

The antiapoptotic, antioxidant, proliferative, and angiogenic effects of metallothionein (MT)-I+II has resulted in increased focus on their role in oncogenesis, tumor progression, therapy response, and patient prognosis. Studies have reported increased expression of MT-I+II mRNA and protein in various human cancers; such as breast, kidney, lung, nasopharynx, ovary, prostate, salivary gland, testes, urinary bladder, cervical, endometrial, skin carcinoma, melanoma, acute lymphoblastic leukemia (ALL), and pancreatic cancers, where MT-I+II expression is sometimes correlated to higher tumor grade/stage, chemotherapy/radiation resistance, and poor prognosis. However, MT-I+II are downregulated in other types of tumors (e.g. hepatocellular, gastric, colorectal, central nervous system (CNS), and thyroid cancers) where MT-I+II is either inversely correlated or unrelated to mortality. Large discrepancies exist between different tumor types, and no distinct and reliable association exists between MT-I+II expression in tumor tissues and prognosis and therapy resistance. Furthermore, a parallel has been drawn between MT-I+II expression as a potential marker for prognosis, and MT-I+II's role as oncogenic factors, without any direct evidence supporting such a parallel. This review aims at discussing the role of MT-I+II both as a prognostic marker for survival and therapy response, as well as for the hypothesized role of MT-I+II as causal oncogenes.