Comparative study on modeccin- and phytohemagglutinin (PHA)-induced secretion of cytokines and nitric oxide (NO) in RAW264.7 cells

Chlorpyrifos pesticide promotes oxidative stress and increases inflammatory states in BV-2 microglial cells: A role in neuroinflammation

The exposure to environmental stressors, such as organophosphate (OP) pesticides, has been associated with the development of neurodegenerative diseases. Chlorpyrifos (CPF) is the worldwide most used OP pesticide and one of the most hazardous pesticides as it can cross the blood-brain barrier. Since studies evaluating the effects of CPF on brain immune cells are scarce, this research investigated the oxidative and inflammatory responses of CPF exposure in murine microglial cells. BV-2 cells were exposed to different concentrations of CPF pesticide (0.3-300 μM). CPF induced activation of microglial cells, confirmed by Iba-1 and CD11b marking, and promoted microglial proliferation and cell cycle arrest at S phase. Moreover, CPF exposure increased oxidative stress production (NO, MDA, and O₂∙), and upregulated pro-inflammatory cytokines (IL-1β and NLRP3) genes expression in BV-2 cells. Overall, data showed that CPF exposure, at the lowest concentrations, acted by promoting pro-oxidative and pro-inflammatory states in microglial cells. These results provide important information on the potential role of microglial activation in CPF-induced neuroinflammation and add to the expanding knowledge on the neurotoxicity of OP.

Ribosome-Inactivating Protein α-Momorcharin Derived from Edible Plant Momordica charantia Induces Inflammatory Responses by Activating the NF-kappaB and JNK Pathways

Alpha-momorcharin (α-MMC), a member of the ribosome-inactivating protein (RIP) family, has been found in the seeds of Momordica charantia (bitter melon). α-MMC contributes a number of pharmacological activities; however, its inflammatory properties have not been well studied. Here, we aim to determine the inflammatory responses induced by recombinant α-MMC and identify the underlying mechanisms using cell culture and animal models. Recombinant α-MMC was generated in Rosetta™(DE3)pLysS and purified by the way of nitrilotriacetic acid (NTA) chromatography. Treatment of recombinant α-MMC at 40 μg/mL exerted sub-lethal cytotoxic effect on THP-1 monocytic cells. Transcriptional profiling revealed that various genes coding for cytokines and other proinflammatory proteins were upregulated upon recombinant α-MMC treatment in THP-1 cells, including MCP-1, IL-8, IL-1β, and TNF-α. Recombinant α-MMC was shown to activate IKK/NF-κB and JNK pathways and the α-MMC-induced inflammatory gene expression could be blocked by IKKβ and JNK inhibitors. Furthermore, murine inflammatory models further demonstrated that α-MMC induced inflammatory responses in vivo. We conclude that α-MMC stimulates inflammatory responses in human monocytes by activating of IKK/NF-κB and JNK pathways, raising the possibility that consumption of α-MMC-containing food may lead to inflammatory-related diseases.

Immunomodulatory effect of mancozeb, chlorothalonil, and thiophanate methyl pesticides on macrophage cells

Mancozeb (MZ), chlorothalonil (CT), and thiophanate methyl (TM) are pesticides commonly used in agriculture due to their efficacy, low acute toxicity to mammals, and short environmental persistence. Although the toxic effects of these pesticides have been previously reported, studies regarding their influence on the immune system are limited. As such, this study focused on the immunomodulatory effect of MZ, CT, and TM pesticides on macrophage cells. RAW 264.7 cells were exposed to a range of concentrations (0.1-100 μg/mL) of these pesticides. CT exposure promoted an increase in reactive oxygen species (ROS) and nitric oxide (NO) levels. The MTT and ds-DNA assay results demonstrated that MZ, CT, and TM exposure induced macrophage proliferation. Moreover, MZ, CT, and TM promoted cell cycle arrest at S phase, strongly suggesting macrophage proliferation. The levels of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α, and IFN-γ) and caspases (caspase 1, 3, and 8) in macrophages exposed to MZ, CT, and TM pesticides increased, whereas the anti-inflammatory cytokine levels decreased. These results suggest that MZ, CT, and TM exert an immunomodulatory effect on the immune system, inducing macrophage activation and enhancing the inflammatory response.

Polymorphism eNOS Glu298Asp modulates the inflammatory response of human peripheral blood mononuclear cells

INTRODUCTION

Nitric oxide is a gaseous radical produced by the nitric oxide endothelial synthase (eNOS) whose most studied physiological action is the vasodilation. However, it also acts in the defense of the organism through the formation of cytotoxic radicals, which can potentiate the inflammatory lesion of the cells. The Glu298Asp is a single nucleotide polymorphism (SNP) in the eNOS gene related to the risk of cardiovascular disease. Blacks present a higher prevalence of hypertension and cardiovascular mortality. Then, we aimed to evaluate the influence of Glu298Asp polymorphism on inflammatory response in vitro and gene expression in blacks.

MATERIAL AND METHODS

Peripheral blood mononuclear cells (PBMC) from blacks with different Glu298Asp genotypes were treated with phytohemagglutinin (PHA), a mitogen and activator of T cells. Oxidative, inflammatory markers, and expression of inflammation genes were evaluated.

RESULTS

The genotype frequencies were TT 6.7%; TG 29.3% and GG 64.0%. Activation of PBMCs with 125 μg of PHA modulated the expression of inflammatory genes and increased levels of inflammatory cytokines. The T allele showed increased susceptibility to inflammation (higher levels of interleukin 1, interleukin 6 and tumor necrosis factor alpha; p < 0.001). The G allele exhibited protection through higher levels of nitric oxide (p < 0.001) and fewer inflammatory cytokines.

CONCLUSION

Despite methodological limitations related to in vitro assays, the whole of results suggested that Glu298Asp modulates inflammatory genes, the T allele is more susceptible to inflammation and the G allele is protective.

Evaluation of the anti-oxidant and anti-inflammatory effects of the methanolic extract of Ferula szowitsiana root on PHA-induced inflammation in human lymphocytes

Inflammation is defined as a defensive response of the body against either the endogenous or exogenous triggers, while this process becomes chronic leading to various disorders such as asthma, cancers, and multiple sclerosis. Recently, pharmacological properties of different constituents of F. szowitsiana have been reported. In the present study, we aimed to evaluate the anti-oxidative and anti-inflammatory effects of the methanolic extract of F. szowitsiana root on human isolated lymphocytes. The effects of either F. szowitsiana (10, 40 and 160 μg/ml) or dexamethasone (0.1 mM) were evaluated on the levels of cell proliferation, reactive oxygen species (ROS), nitric oxide (NO) production, malondialdehyde (MDA), superoxide dismutase (SOD) and catalase (CAT) activities, and total glutathione content (GSH) as well as the secretion of inflammatory cytokines [interleukin 6 (IL-6) and tumor necrosis factor (TNF)-α] in the presence or absence of phytohemagglutinin (PHA) stimulation (n = 8 for each group). PHA stimulation notably elevated ROS, NO, MDA, IL-6, and TNF-α levels as well as diminished GSH, CAT and SOD levels. In PHA-stimulated, the results also revealed that F. szowitsiana (10-160 µg/ml) significantly decreased MDA, ROS, NO, IL-6 and TNF-α levels as well as increased CAT, SOD and GSH levels. Collectively, F. szowitsiana is able to attenuate the overproduction of inflammatory and oxidative stress markers in the presence of PHA-stimulated T lymphocytes, while to propagate the anti-oxidative defense. Contextually, the plant has promising healing effects in the different inflammatory disorders associated with the interference of the acquired immune system such as multiple sclerosis and asthma.

Ziprasidone, a second-generation antipsychotic drug, triggers a macrophage inflammatory response in vitro

Antipsychotic drugs are used to treat schizophrenia and other psychiatric disorders. However, most of these drugs present side effects causing obesity and other serious metabolic alterations that correlate with grade of chronic inflammation. In contrast, ziprasidone's (ZIP) metabolic side effects are attenuated relative to those of other antipsychotic drugs, but some reports suggest that this drug could cause allergic, hypersensitive reactions in susceptible patients. At present, the mechanism of ZIP's effect on peripheral inflammatory metabolism is not well characterized. We conducted an in vitro study to evaluate the effect of ZIP on a macrophage cell line (RAW 264.1). Our results showed that in non-activated macrophage cells, ZIP exposure initiated macrophage spreading; increased cellular proliferation, as evaluated by MTT and flow cytometry assays; and presented higher levels of oxidant molecules involved in the inflammatory response (nitric oxide, superoxide, reactive oxygen species), and proinflammatory cytokines (IL-1, IL-6, TNFα, INFγ). Levels of IL-10, an anti-inflammatory cytokine were lower in ZIP-exposed cells. These effects were less potent than those caused by the positive control for inflammation induction (phytohemagglutinin), and more intense than the effects of lithium (LI), which was used as an anti-inflammatory molecule. ZIP also modulated cytokine gene expression. Taken together, these data suggest that ZIP can produce a peripheral inflammatory response, and this response may explain the allergen-inflammatory response observed in some patients treated with this antipsychotic drug.

Macrophage-stimulating activities of newly isolated complex polysaccharides from Parachlorella kessleri strain KNK-A001

Our previous studies demonstrated that the microalga Parachlorella kessleri (KNK-A001) has immunostimulatory activities, which were observed as an increase in natural killer (NK) cell activity in mice after intraperitoneal injection or as a protective effect on a virus-infected model shrimp after oral administration. In this study, we attempted to gain insight into the constituent substances of KNK-A001 that are responsible for the immunostimulatory activity. First, we obtained five polysaccharide fractions from KNK-A001 by DEAE anion exchange chromatography. Among the fractions, F5 showed the most potent induction of nitric oxide (NO) secretion in RAW264.7 cells, and both mRNA and protein expression levels of inducible NO synthase (iNOS) were increased in F5-treated RAW264.7 cells. A significant increase in the nuclear translocation of the p65 subunit of nuclear factor-kappa B (NF-κB) was observed in F5-treated RAW264.7 cells. F5 also induced the secretion of tumor necrosis factor (TNF)-α in RAW264.7 cells. Analysis using mitogen-activated protein (MAP) kinase inhibitors suggested that c-Jun N-terminal kinase (JNK) and p38 MAP kinase were mainly involved in F5-induced NO and TNF-α productions. The compositional analysis of F5 identified the main constituents as galactose, glucose, galacturonic acid, and mannose. Gel-filtration analysis suggested that molecular mass of F5 was approximately 400kDa.

Antioxidant and anti-inflammatory activity of Ocimum labiatum extract and isolated labdane diterpenoid

Background

Plants from the genus Ocimum are used as folk medicine for treating various diseases including inflammatory and immune-related diseases. Numerous reports have suggested plant extracts and their constituents as possible anti-inflammatory agents. Here, in vitro evidence of Ocimum labiatum’s immune-enhancing and antioxidant properties is presented for the first time.

Methods

The anti-inflammatory effect of O. labiatum ethanolic extract and an isolated diterpenoid was determined using a cytometric bead array (CBA) technique. The effect on phytohemagglutinin (PHA)-induced nitric oxide (NO) production in peripheral blood mononuclear cells (PBMCs) was also assessed. A battery of antioxidant assays were used for detecting antioxidant activity while the anti-inflammatory mechanism was evaluated using an ELISA-based activator protein (AP-1) (c-Jun) assay. Cytotoxicity was determined on TZM-bl and PBMCs using a tetrazolium dye and confirmed by a novel label-free real-time assay.

Results

A 25 μg/mL non-cytotoxic concentration of O. labiatum extract significantly (p < 0.05) inhibited the production of pro-inflammatory cytokines; IL-2, IL-4, IL-6 and IL-17A. Except for the dual acting pro- or anti-inflammatory cytokine, IL-6, which was upregulated, a non-cytotoxic 50 μM concentration of the isolated labdane diterpenoid compound significantly (p < 0.05) decreased the production of all the pro-inflammatory cytokines. In the anti-inflammatory pathway studies, the compound also inhibited AP-1 significantly (p < 0.05) at 50 μM. The extract demonstrated strong, dose dependent antioxidant activity with IC₅₀ values ranging from 13 ± 0.8 to 54.86 ± 1.28 μg/mL while the terpene had no antioxidant property. The extract and diterpenoid decreased the production of the inflammatory mediator NO, at non-cytotoxic concentrations. The CC₅₀ of the extract in TZM-bl and PBMCs was 62.6 ± 0.6 and 30.1 ± 0.4 μg/mL while that of the compound was 112.6 ± 0.2 and 70 ± 0.4 μM respectively. The real time studies confirmed tetrazolium dye assessed viability and also detected a unique growth pattern for the plant materials compared to untreated cells.

Conclusions

O. labiatum extract demonstrated promising anti-inflammatory and antioxidant properties while the terpenoid showed anti-inflammatory but no antioxidant activity. The anti-inflammatory mechanism of the terpene was a result of inhibition of AP-1. These data represents promising first steps towards the development of naturally derived anti-inflammation drugs.

Phytohemagglutinin improves the development and ultrastructure of in vitro-cultured goat (Capra hircus) preantral follicles

The objective this study was to determine the effect of phytohemagglutinin (PHA) on survival, growth and gene expression in caprine secondary follicles cultured in vitro. Secondary follicles (∼0.2 mm) were isolated from the cortex of caprine ovaries and cultured individually for 6 days in α-MEM⁺ supplemented with PHA (0, 1, 10, 50, 100, or 200 µg/mL). After 6 days of culture, follicle diameter and survival, antrum formation, ultrastructure and expression of mRNA for FSH receptors (FSH-R), proliferating cell nuclear antigen (PCNA), and neuronal nitric oxide synthase were determined. All treatments maintained follicular survival [α-MEM⁺ (94.59%); 1 µg/mL PHA (96.43%); 10 µg/mL PHA (84.85%); 50 µg/mL PHA (85.29%); 100 µg/mL PHA (88.57%), and 200 µg/mL PHA (87.50)], but the presence of 10 µg/mL PHA in the culture medium increased the antrum formation rate (21.21%) when compared with control (5.41%, P < 0.05) and ensured the maintenance of oocyte and granulosa cell ultrastructures after 6 days of culture. The expression of mRNA for FSH-R (2.7 ± 0.1) and PCNA (4.4 ± 0.2) was also significantly increased in follicles cultured with 10 µg/mL PHA in relation to those cultured in α-MEM⁺ (1.0 ± 0.1). In conclusion, supplementation of culture medium with 10 µg/mL PHA maintains the follicular viability and ultrastructure, and promotes the formation of antral cavity after 6 days of culture in vitro.

No evidence for an anti-inflammatory effect of escitalopram intervention in healthy individuals with a family history of depression

Inflammation may contribute to the pathogenesis of depression and antidepressants are hypothesised to have an anti-inflammatory effect. In this randomised double-blinded trial we investigated the cytokine levels in supernatants of stimulated whole blood samples from first degree relatives to patients with depression randomised to a single daily dose of either 10mg escitalopram or placebo for four weeks. No significant differences were found in any of the cytokine levels between the participants treated with escitalopram (n=21) or placebo (n=23). Our data does thus not support the hypothesis of a global anti-inflammatory effect of escitalopram on cytokines in healthy subjects.

The potent activity of sulfated polysaccharide, ascophyllan, isolated from Ascophyllum nodosum to induce nitric oxide and cytokine production from mouse macrophage RAW264.7 cells: Comparison between ascophyllan and fucoidan

Ascophyllan isolated from the brown alga Ascophyllum nodosum is a fucose-containing sulfated polysaccharide, which has similar but distinct characteristic monosaccharide composition and entire chemical structure to fucoidan. In this study, we examined the effects of ascophyllan, fucoidan isolated from A. nodosum (A-fucoidan), and fucoidan from Sigma (S-fucoidan) as a representative fucoidan derived from other source (Fucus vesiculosus) on mouse macrophage cell line RAW264.7 cells. No significant cytotoxic effects of ascophyllan and A-fucoidan on RAW264.7 cells were observed up to 1000μg/ml, while S-fucoidan showed cytotoxic effect in a concentration-dependent manner. Ascophyllan induced extremely higher level of nitric oxide (NO) production from RAW264.7 cells than those induced by fucoidans over the concentration range tested (0-200μg/ml). Reverse transcription polymerase chain reaction (RT-PCR) and western blot analysis revealed that expression level of inducible NO synthase (iNOS) in ascophyllan-treated RAW264.7 cells was much higher than the levels detected in the cells treated with fucoidans. Furthermore, the activities of ascophyllan to induce the secretion of tumor necrosis factor-α (TNF-α) and granulocyte colony-stimulating factor (G-CSF) from RAW264.7 cells were also greater than those induced by fucoidans especially at lower concentration range (3.1-50μg/ml). The activities of ascophyllan to induce NO and cytokine production in mouse peritoneal macrophages were also stronger than those of fucoidans. Electrophoretic mobility shift assay (EMSA) using infrared dye labeled nuclear factor-kappa B (NF-κB) and AP-1 consensus sequences suggested that ascophyllan can strongly activate these transcription factors. Marked increase in the nuclear translocation of p65, and the phosphorylation and degradation of IκB-α were also observed in ascophyllan-treated RAW264.7 cells. Analysis using mitogen-activated protein (MAP) kinase inhibitors and western blot analysis suggested that c-Jun N-terminal kinase (JNK) and p38 MAP kinase are mainly involved in ascophyllan-induced NO production.