Redox- and oxidant-mediated regulation of interleukin-10: an anti-inflammatory,antioxidant cytokine?

Reduction-oxidation (redox) state constitutes such a potential signaling mechanism for the regulation of an inflammatory signal associated with oxidative stress. Interleukin (IL)-10 has recently emerged as an anti-inflammatory cytokine with antioxidant properties. Interestingly, redox- and oxidant-mediated pathways positively and/or negatively regulate the expression, distribution, and functional properties of IL-10, thus, allowing the evolution of what is known as an anti-inflammatory redox-oxidant revolving axis. This axis is directly involved in regulating phosphorylation mechanisms, which eventually control gene expression and the biosynthesis of oxidative stress-related cofactors, such as reactive species and inflammatory cytokines. The association between IL-10, an anti-inflammatory antioxidant, with redox- and oxidant-related pathways governing the regulation of inflammatory and closely dependent processes is thereafter discussed.     

Morin Mitigates Chronic Constriction Injury (CCI)-Induced Peripheral Neuropathy by Inhibiting Oxidative Stress Induced PARP Over-Activation and Neuroinflammation

Neuropathic pain is initiated or caused due to the primary lesion or dysfunction in the nervous system and is proposed to be linked to a cascade of events including excitotoxicity, oxidative stress, neuroinflammation and apoptosis. Oxidative/nitrosative stress aggravates the neuroinflammation and neurodegeneration through poly (ADP) ribose polymerase (PARP) overactivation. Hence, the present study investigated the antioxidant and anti-inflammatory effects of the phytoconstituent; morin in chronic constriction injury (CCI) induced neuropathy. Neuropathic pain was induced by chronic constriction of the left sciatic nerve in rats, and the effect of morin (15 and 30 mg/kg, p.o.) was evaluated by measuring behavioural and biochemical changes. Mechanical, chemical and thermal stimuli confirmed the CCI-induced neuropathic pain and treatment with morin significantly improved these behavioural deficits and improved the sciatic functional index by the 14th day after CCI induction. After 14 days of CCI induction, oxidative/nitrosative stress and inflammatory markers were elevated in rat lumbar spinal cord. Oxidative stress induced PARP overactivation resulted in depleted levels of ATP and elevated levels of poly (ADP) ribose (PAR). Treatment with morin reduced the levels of nitrites, restored glutathione levels and abrogated the oxidant induced DNA damage. It also mitigated the increased levels of TNF-α and IL-6. Protein expression studies confirmed the PARP inhibition and anti-inflammatory activity of morin. Findings of this study suggest that morin, by virtue of its antioxidant properties, limited PARP overactivation and neuroinflammation and protected against CCI induced functional, behavioural and biochemical deficits.     

(-)-Epigallocatechin-3-gallate and hydroxytyrosol improved antioxidative and anti-inflammatory responses in bovine mammary epithelial cells

(-)-Epigallocatechin-3-gallate (EGCG), the major phenolic compound of green tea, and hydroxytyrosol (HTyr), a phenol found in olive oil, have received attention due to their wide-ranging health benefits. To date, there are no studies that report their effect in bovine mammary gland. Therefore, the aim of this study was to evaluate the anti-oxidative and anti-inflammatory effects of EGCG and HTyr in bovine mammary epithelial cell line (BME-UV1) and to compare their antioxidant and anti-inflammatory in vitro efficacy. Sample of EGCG was obtained from a commercially available green tea extract while pure HTyr was synthetized in our laboratories. The mammary oxidative stress and inflammatory responses were assessed by measuring the oxidative stress biomarkers and the gene expression of inflammatory cytokines. To evaluate the cellular antioxidant response, glutathione (GSH/GSSH), γ-glutamylcysteine ligase activity, reactive oxygen species and malondialdehyde (MDA) production were measured after 48-h incubation of 50 µM EGCG or 50 µM of HTyr. Reactive oxygen species production after 3 h of hydrogen peroxide (50 µM H₂O₂) or lipopolysaccharide (20 µM LPS) exposure was quantified to evaluate and to compare the potential protection of EGCG and HTyr against H₂O₂-induced oxidative stress and LPS-induced inflammation. The anti-inflammatory activity of EGCG and HTyr was investigated by the evaluation of pro and anti-inflammatory interleukins (tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and IL-10) messenger RNA abundance after treatment of cells for 3 h with 20 µM of LPS. Data were analyzed by one-way ANOVA. (-)-Epigallocatechin-3-gallate or HTyr treatments induced higher concentrations of intracellular GSH compared to control cells, matched by an increase of γ-glutamylcysteine ligase activity mainly in cells treated with HTyr. Interestingly, EGCG and HTyr prevented oxidative lipid damage in the BME-UV1 cells by a reduction of intracellular MDA levels. (-)-Epigallocatechin-3-gallate and HTyr were able to enhance cell resistance against H₂O₂-induced oxidative stress. It was found that EGCG and HTyr elicited a reduction of the three inflammatory cytokines TNF-α, IL-1β, IL-6 and an increase of the anti-inflammatory cytokine IL-10. Hydroxytyrosol has proved to be a strong antioxidant compound, and EGCG has shown mainly an anti-inflammatory profile. These results indicated that EGCG and HTyr may provide dual protection because they were able to attenuate oxidative stress and inflammatory responses, suggesting that these phenolic compounds are potential natural alternatives to be used in dairy cattle as feed supplement for reducing the development of oxidative and inflammatory processes related to parturition or as topical treatments for the control of bovine intramammary inflammation.     

Fingolimod attenuates ovalbumin-induced airway inflammation via inhibiting MAPK/ERK signaling in mice

The current study was designed to investigate the potential anti-inflammatory and antioxidant effects of fingolimod against Ovalbumin (Ova)-induced allergic airway inflammation compared to dexamethasone. Fingolimod was given (0.5 mg/kg/day, p.o.) for sensitized mice 1 h before Ova challenge from Days 19 to 24. Fingolimod significantly inhibited Ova-induced elevation of inflammatory cells and eosinophils numbers in bronchoalveolar lavage fluid (BALF) and reduced concentrations of immunoglobulin E in serum and of sphingosine-1-phosphate, interleukin (IL)-4, and IL-13 in BALF. Fingolimod inhibited microvascular leakage and edema as reflected by the decreased lung/body weight index. These findings were supported by histopathological examination results showing that fingolimod substantially decreased perivascular edema and inflammatory cell infiltration. Fingolimod also attenuated Ova-induced oxidative stress as evidenced by decreased malondialdehyde concentration along with increasing concentrations of reduced glutathione and superoxide dismutase in lung tissues. Fingolimod also significantly decreased monocyte chemoattractant protein-1 (MCP-1), p-ERK, and p-P38 in lung tissues of Ova-challenged mice. In conclusion, the current study demonstrated the anti-inflammatory and antioxidant effects of fingolimod in allergic airway inflammation that might be associated with the downregulation of mitogen activated kinases signaling to decrease T helper 2 cytokine secretion (IL-4 and IL-13) and MCP-1 expression, along with the inhibition of oxidative stress.     

Potential role of dietary flavonoids in reducing microvascular endothelium vulnerability to oxidative and inflammatory insults ( small star,filled)

Although antioxidant systems help control the level of reactive oxygen species they may be overwhelmed during periods of oxidative stress. Evidence suggests that oxidative stress components as well as inflammatory mediators may be involved in the pathogenesis of vascular disorders, where localized markers of oxidative damage have been found. In this regard we investigated the putative antioxidant and anti-inflammatory effects of blueberry and cranberry anthocyanins and hydroxycinnamic acids against H(2)O(2) and TNFalpha induced damage to human microvascular endothelial cells. Polyphenols from both berries were able to localize into endothelial cells subsequently reducing endothelial cells vulnerability to increased oxidative stress at both the membrane and cytosol level. Furthermore, berry polyphenols also reduced TNFalpha induced up-regulation of various inflammatory mediators (IL-8, MCP-1 and ICAM-1) involved in the recruitment of leukocytes to sites of damage or inflammation along the endothelium. In conclusion, polyphenols isolated from both blueberry and cranberry were able to afford protection to endothelial cells against stressor induced up-regulation of oxidative and inflammatory insults. This may have beneficial actions against the initiation and development of vascular diseases and be a contributing factor in the reduction of age-related deficits in neurological impairments previously reported by us.     

Vinpocetine Reduces Carrageenan-Induced Inflammatory Hyperalgesia in Mice by Inhibiting Oxidative Stress,Cytokine Production and NF-κB Activation in the Paw and Spinal Cord

Vinpocetine is a safe nootropic agent used for neurological and cerebrovascular diseases. The anti-inflammatory activity of vinpocetine has been shown in cell based assays and animal models, leading to suggestions as to its utility in analgesia. However, the mechanisms regarding its efficacy in inflammatory pain treatment are still not completely understood. Herein, the analgesic effect of vinpocetine and its anti-inflammatory and antioxidant mechanisms were addressed in murine inflammatory pain models. Firstly, we investigated the protective effects of vinpocetine in overt pain-like behavior induced by acetic acid, phenyl-p-benzoquinone (PBQ) and formalin. The intraplantar injection of carrageenan was then used to induce inflammatory hyperalgesia. Mechanical and thermal hyperalgesia were evaluated using the electronic von Frey and the hot plate tests, respectively, with neutrophil recruitment to the paw assessed by a myeloperoxidase activity assay. A number of factors were assessed, both peripherally and in the spinal cord, including: antioxidant capacity, reduced glutathione (GSH) levels, superoxide anion, tumor necrosis factor alpha (TNF-α) and interleukin 1 beta (IL-1β) levels, as well as nuclear factor kappa B (NF-κB) activation. Vinpocetine inhibited the overt pain-like behavior induced by acetic acid, PBQ and formalin (at both phases), as well as the carrageenan-induced mechanical and thermal hyperalgesia and associated neutrophil recruitment. Both peripherally and in the spinal cord, vinpocetine also inhibited: antioxidant capacity and GSH depletion; increased superoxide anion; IL-1β and TNF-α levels; and NF-κB activation. As such, vinpocetine significantly reduces inflammatory pain by targeting oxidative stress, cytokine production and NF-κB activation at both peripheral and spinal cord levels.     

Cholinergic anti-inflammatory pathway confers airway protection against oxidative damage and attenuates inflammation in an allergic asthma model

Asthma is characterized by the influx of inflammatory cells, especially of eosinophils as well as reactive oxygen species (ROS) production, driven by the release of the T helper 2 (Th2)-cell-associated cytokines. The cholinergic anti-inflammatory pathway (CAP) inhibit cytokines production and controls inflammation. Thus, we investigated the effects of pharmacological activation of CAP by neostigmine on oxidative stress and airway inflammation in an allergic asthma model. After the OVA challenge, mice were treated with neostigmine. We showed that CAP activation by neostigmine reduced the levels of pro-inflammatory cytokines (IL-4, IL-5, IL-13, IL-1β, and TNF-α), which resulted in a decrease of eosinophils influx. Furthermore, neostigmine also conferred airway protection against oxidative stress, attenuating ROS production through the increase of antioxidant defense, evidenced by the catalase (CAT) activity. We propose, for the first time, that pharmacological activation of the CAP can lead to new possibilities in the therapeutic management of allergic asthma.     

The citrus flavonone naringenin reduces lipopolysaccharide-induced inflammatory pain and leukocyte recruitment by inhibiting NF-κB activation

Lipopolysaccharide (LPS) is the major structural component of Gram-negative bacteria cell wall and a highly pro-inflammatory toxin. Naringenin is found in Citrus fruits and exhibits antioxidant and anti-inflammatory properties through inhibition of NF-κB activation but its effects in LPS-induced inflammatory pain and leukocyte recruitment were not investigated yet. We investigated the effects of naringenin in mechanical hyperalgesia, thermal hyperalgesia and leukocyte recruitment induced by intraplantar injection of LPS in mice. We found that naringenin reduced hyperalgesia to mechanical and thermal stimuli, myeloperoxidase (MPO, a neutrophil and macrophage marker) and N-acetyl-β-D-glucosaminidase (NAG, a macrophage marker) activities, oxidative stress and cytokine (TNF-α, IL-1β, IL-6, and IL-12) production in the paw skin. In the peritoneal cavity, naringenin reduced neutrophil and mononuclear cell recruitment, and abrogated MPO and NAG activity, cytokine and superoxide anion production, and lipid peroxidation. In vitro, pre-treatment with naringenin inhibited superoxide anion and cytokine (TNF-α, IL-1β, IL-6, and IL-12) production by LPS-stimulated RAW 264.7 macrophages. Finally, we demonstrated that naringenin inhibited NF-κB activation in vitro and in vivo. Therefore, naringenin is a promising compound to treat LPS-induced inflammatory pain and leukocyte recruitment.     

Exposure to Far Infrared Ray Protects Methamphetamine-Induced Behavioral Sensitization in Glutathione Peroxidase-1 Knockout Mice via Attenuating Mitochondrial Burdens and Dopamine D1 Receptor Activation

Evidence indicates that stress conditions might lead to drug dependence. Recently, we have demonstrated that exposure to far infrared ray (FIR) attenuates acute restraint stress via induction of glutathione peroxidase-1 (GPx-1) gene. We investigated whether FIR affects methamphetamine (MA)-induced behavioral sensitization and whether FIR-mediated pharmacological activity requires interaction between dopamine receptor and GPx-1 gene. We observed that MA treatment significantly increased GPx-1 expression in the striatum of wild-type (WT) mice. Interestingly, exposure to FIR potentiated MA-induced increase in GPx-1 expression. This phenomenon was also observed in animals receiving MA with dopamine D1 receptor antagonist SCH23390. However, dopamine D2 receptor antagonist sulpiride did not affect MA-induced GPx-1 expression. FIR exposure or SCH23390, but not sulpiride, significantly attenuated MA-induced behavioral sensitization. Exposure to FIR significantly attenuated MA-induced dopamine D1 receptor expression, c-Fos induction and oxidative burdens. FIR-mediated antioxidant effects were also more pronounced in mitochondrial- than cytosolic-fraction. In addition, FIR significantly attenuated against MA-induced changes in mitochondrial superoxide dismutase and mitochondrial GPx activities, mitochondrial transmembrane potential, intramitochondrial Ca²⁺ level, mitochondrial complex-I activity, and mitochondrial oxidative burdens. The attenuation by FIR was paralleled that by SCH23390. Effects of FIR or SCH23390 were more sensitive to GPx-1 KO than WT mice, while SCH23390 treatment did not exhibit any additive effects on the protective activity mediated by FIR, indicating that dopamine D1 receptor constitutes a molecular target of FIR. Our result suggests that exposure to FIR ameliorates MA-induced behavioral sensitization via possible interaction between dopamine D1 receptor and GPx-1 gene.     

Antioxidant Efficacy of Esculetin against Tert-Butyl Hydroperoxide-Induced Oxidative Stress in HEK293 Cells

Esculetin is an antioxidant and anti-inflammatory compound derived from coumarin. Oxidative stress can cause overproduction of reactive oxygen species (ROS), which can lead to the development of chronic kidney failure. In this study, human embryonic kidney 293 (HEK293) cells were treated with tert-butyl hydroperoxide (t-BHP) to determine the antioxidant effects of esculetin. HEK293 cells were treated with t-BHP to validate changes in cell viability, ROS production, and apoptosis, and then treated with esculetin to evaluate the changes. Changes in mRNA and protein levels were analyzed using a proteome kit, PCR, and Western blotting. Esculetin improved HEK293 cell viability and reduced apoptosis caused by t-BHP-induced oxidative stress. At the mRNA and protein levels, esculetin decreased pro-apoptotic factor expression as well as increased anti-apoptotic factor expression. The antioxidant efficacy of esculetin was validated when it inhibited the apoptosis caused by t-BHP-induced oxidative stress in HEK293 cells.     

Effect of coenzyme Q10 on mitochondrial respiratory proteins in trigeminal neuralgia

Trigeminal neuralgia (TN) is the neuropathic pain. Mitochondrial dysfunction, increased oxidative stress, and inflammation demonstrated in chronic pain. Carbamazepine (CBZ) is the first-line drug for TN, however, it is still insufficient. Coenzyme Q10 (CoQ10) has been used as the additional supplement for pain therapy. Nonetheless, mitochondrial respiratory proteins, oxidative stress, and inflammation in TN, and the add-on effects of CoQ10 on those defects have never been investigated. CBZ-treated TN-patients, naïve TN-patients, and control subjects were included. CBZ-treated TN-patients were randomised into two subgroups, received either CoQ10 or placebo for 2 months. Pain levels were evaluated, and peripheral blood mononuclear cells were isolated to determine the oxidative stress, mitochondrial oxidative phosphorylation (OXPHOS), peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), and cytokines including TNF-α, IL-1β and IL-18 mRNA expression. Pain scales, oxidative stress, and OXPHOS levels were greater in naïve TN-patients than control, whereas the cytokine profiles were unchanged. Although pain scales were lower in CBZ-treated TN-patients than in naïve TN-patients, oxidative stress, OXPHOS, and cytokine expression profiles were not different. PGC-1α levels found to be increased in CBZ-treated TN patients when compared with the naïve group. CoQ10 supplement in CBZ-treated TN patients reduced pain scale and oxidative stress and increased antioxidants levels when compared with placebo group. However, OXPHOS, PGC-1α, and cytokines were not different between groups. These findings suggest that increased oxidative stress could be potentially involved in the pathogenesis of TN. CoQ10 supplements can reduce oxidative stress, leading to more effective pain reduction in TN patients being treated with CBZ.     

Costunolide alleviates hyperglycaemia-induced diabetic cardiomyopathy via inhibiting inflammatory responses and oxidative stress

Hyperglycaemia-induced myocardial injury promotes the induction of heart failure in diabetic patients. Impaired antioxidant capability and sustained chronic inflammation play a vital role in the progression of diabetic cardiomyopathy (DCM). Costunolide (Cos), a natural compound with anti-inflammatory and antioxidant properties, has exhibited therapeutic effects in various inflammatory diseases. However, the role of Cos in diabetes-induced myocardial injury remains poorly understood. In this study, we investigated the effect of Cos on DCM and explored the potential mechanisms. C57BL/6 mice were administered intraperitoneal streptozotocin for DCM induction. Cos-mediated anti-inflammatory and antioxidation activities were examined in heart tissues of diabetic mice and high glucose (HG)-stimulated cardiomyocytes. Cos markedly inhibited HG-induced fibrotic responses in diabetic mice and H9c2 cells, respectively. The cardioprotective effects of Cos could be correlated to the reduced expression of inflammatory cytokines and decreased oxidative stress. Further investigations demonstrated Cos reversed diabetes-induced nuclear factor-κB (NF-κB) activation and alleviated impaired antioxidant defence system, principally via activation of nuclear factor-erythroid 2 p45-related factor-2 (Nrf-2). Cos alleviated cardiac damage and improved cardiac function in diabetic mice by inhibiting NF-κB-mediated inflammatory responses and activating the Nrf-2-mediated antioxidant effects. Therefore, Cos could be a potential candidate for the treatment of DCM.     

Coenzyme Q10 supplementation alleviates pain in pregabalin-treated fibromyalgia patients via reducing brain activity and mitochondrial dysfunction

Although coenzyme Q10 (CoQ10) supplementation has shown to reduce pain levels in chronic pain, the effects of CoQ10 supplementation on pain, anxiety, brain activity, mitochondrial oxidative stress, antioxidants, and inflammation in pregabalin-treated fibromyalgia (FM) patients have not clearly elucidated. We hypothesised that CoQ10 supplementation reduced pain better than pregabalin alone via reducing brain activity, mitochondrial oxidative stress, inflammation, and increasing antioxidant levels in pregabalin-treated FM patients. A double-blind randomised placebo-controlled trial was conducted. Eleven FM patients were enrolled with 2 weeks wash-out then randomly allocated to 2 treatment groups; pregabalin with CoQ10 or pregabalin with placebo for 40 d. Then, patients in CoQ10 group were switched to placebo, and patients in placebo group were switched to CoQ10 for another 40 d. Pain pressure threshold (PPT), FM questionnaire, anxiety, and pain score were examined. Peripheral blood mononuclear cells (PBMCs) were isolated to investigate mitochondrial oxidative stress and inflammation at day 0, 40, and 80. The level of antioxidants and brain positron emission tomography (PET) scan were also determined at these time points. Pregabalin alone reduced pain and anxiety via decreasing brain activity compared with their baseline. However, it did not affect mitochondrial oxidative stress and inflammation. Supplementation with CoQ10 effectively reduced greater pain, anxiety and brain activity, mitochondrial oxidative stress, and inflammation. CoQ10 also increased a reduced glutathione levels and superoxide dismutase (SOD) levels in FM patients. These findings provide new evidence that CoQ10 supplementation provides further benefit for relieving pain sensation in pregabalin-treated FM patients, possibly via improving mitochondrial function, reducing inflammation, and decreasing brain activity.     

"Effect of resveratrol on oxidative and inflammatory stress in liver and spleen of streptozotocin-induced type 1 diabetic rats"

"It has been well known that both oxidative stress and inflammatory activity play crucial roles in the pathogenesis of type 1 diabetes mellitus (T1DM). Resveratrol (RSV), a naturally occurring polyphenol found in grapes and red wine, has recently been shown to exert potent anti-diabetic, anti-oxidative and anti-inflammatory actions. In the present study, we investigated the effect of RSV on oxidative stress and inflammatory response in the liver and spleen of streptozotocin (STZ)-induced type 1 diabetic animal models. Male Long-Evans rats were injected with 65 mg/kg STZ to induce diabetes for 2 weeks, and subsequently administrated with the dosage of 0.1 or 1 mg/kg/day RSV for 7 consecutive days. Hepatic and splenic tissues were dissected for evaluation of oxidative and inflammatory stress. Oxidative stress was assessed by quantification of oxidative indicators including superoxide anion content, lipid and protein oxidative products, as well as manganese superoxide dismutase (Mn-SOD) and nitro-tyrosine protein expression levels. Inflammatory stress was evaluated by the levels of nuclear factor κB (NF-κB) and the proinflammatory cytokine tumor necrosis factorα (TNF-α), interleukin 1 β (IL-1 β ) and IL-6. The experimental results indicated that RSV significantly decreased oxidative stress (superoxide anion content, protein carbonyl level and Mn-SOD expression) in both tissues and hepatic inflammation (NF- κB and IL-1 β ), but implicated proinflammatory potential of RSV in diabetic spleen (TNF-α and IL-6). The results of this study suggest that RSV may serve as a potent antioxidant, but RSV possesses a proinflammatory potential in certain circumstances in diabetes."     

Forsythiaside A Exhibits Anti-inflammatory Effects in LPS-Stimulated BV2 Microglia Cells Through Activation of Nrf2/HO-1 Signaling Pathway

Inflammation and oxidative stress have been reported to play critical roles in the pathogenesis of neurodegenerative disease. Forsythiaside A, a phenylethanoside product isolated from air-dried fruits of Forsythia suspensa, has been reported to have anti-inflammatory and antioxidant effects. In this study, the anti-inflammatory effects of forsythiaside A on LPS-stimulated BV2 microglia cells and primary microglia cells were investigated. The production of inflammatory mediators TNF-α, IL-1β, NO and PGE₂ were detected in this study. NF-κB, nuclear factor-erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1) expression were detected by western blot analysis. Our results showed that forsythiaside A significantly inhibited LPS-induced inflammatory mediators TNF-α, IL-1β, NO and PGE₂ production. LPS-induced NF-κB activation was suppressed by forsythiaside A. Furthermore, forsythiaside A was found to up-regulate the expression of Nrf2 and HO-1. In conclusion, this study demonstrates that forsythiaside A inhibits LPS-induced inflammatory responses in BV2 microglia cells and primary microglia cells through inhibition of NF-κB activation and activation of Nrf2/HO-1 signaling pathway.     

Two dietary polyphenols,fisetin and luteolin,reduce inflammation but augment DNA damage-induced toxicity in human RPE cells

Plant-derived polyphenols are known to possess anti-inflammatory and antioxidant effects. In recent years, several studies have investigated their potential benefits for treating chronic diseases associated with prolonged inflammation and excessive oxidative stress, such as age-related macular degeneration (AMD). Previously, two polyphenols, fisetin and luteolin, have been reported to increase the survival of retinal pigment epithelial (RPE) cells suffering from oxidative stress as well as decreasing inflammation but the benefits of polyphenol therapy seem to depend on the model system used.Our aim was to analyze the effects of fisetin and luteolin on inflammation and cellular viability in a model of nonoxidative DNA damage-induced cell death in human RPE (hRPE) cells. Pretreatment of ARPE-19 or primary hRPE cells with the polyphenols augmented etoposide-induced cell death as measured by the lactate dehydrogenase and 3-(4,5-dimethyldiazol-2-yl)-2,5-diphenyltetrazolium bromide assays. However, the treatment was able to reduce the release of two proinflammatory cytokines, IL-6 and IL-8, which were determined by enzyme-linked Immunosorbent assay. Analyses of caspase 3 activity, p53 acetylation and SIRT1 protein levels revealed the apoptotic nature of etoposide-evoked cell death and that fisetin and luteolin augmented the etoposide-induced acetylation of p53 and decreased SIRT1 levels. Taken together, our findings suggest that the cytoprotective effects of fisetin and luteolin depend on the stressor they need to combat, whereas their anti-inflammatory potential is sustained over a variety of model systems. Careful consideration of disease pathways will be necessary before fisetin or luteolin can be recommended as therapeutic agents for inflammatory diseases in general and specifically AMD.     

Antimicrobial peptide HI-3 from Hermetia illucens alleviates inflammation in lipopolysaccharide-stimulated RAW264.7 cells via suppression of the nuclear factor kappa-B signaling pathway

Hermetia illucens-3 (HI-3), an active insect antimicrobial peptide extracted from H. illucens larvae, exerts antibacterial and anticancer activity. However, the inflammatory effects and their relative molecular mechanisms remain unclear. To explore the inflammatory effects of HI-3, an inflammatory model was induced using 1 ng/mL LPS in RAW264.7 cells. The cell viability and phagocytosis of LPS-stimulated RAW264.7 cells were then detected after HI-3 treatment. Furthermore, the antioxidant activity, the levels of proinflammatory cytokines, and the expression levels of both p65 and inhibitor of nuclear factor kappa B (IκB) were measured. Results showed that HI-3 could inhibit the differentiation, proliferation, phagocytosis, and antioxidant ability, as well as the secretion and messenger RNA expression levels of IL-6, TNF-α, and IL-1β of LPS-induced RAW264.7 cells in a dose-dependent manner. At the same time, the level of the anti-inflammatory cytokine IL-10 was increased after HI-3 treatment. Western blotting results showed that HI-3 suppressed LPS-induced p65 and IκB activation in a dose-dependent manner. Therefore, HI-3 exerts its anti-inflammatory effect by inhibiting the expression of proinflammatory cytokines and the activation of p65 and IκB, which indicated that HI-3 could be a promising therapeutic medicine for inflammation.