Suppression of Lipopolysaccharide-Induced Inflammatory and Oxidative Response by 5-Aminolevulinic Acid in RAW 264.7 Macrophages and Zebrafish Larvae

Extracellular Proteins Isolated from L. acidophilus as an Osteomicrobiological Therapeutic Agent to Reduce Pathogenic Biofilm Formation, Regulate Chronic Inflammation, and Augment Bone Formation In Vitro

Periprosthetic joint infection (PJI) is a challenging complication that can occur following joint replacement surgery. Efficacious strategies to prevent and treat PJI and its recurrence remain elusive. Commensal bacteria within the gut convey beneficial effects through a defense strategy named "colonization resistance" thereby preventing pathogenic infection along the intestinal surface. This blueprint may be applicable to PJI. The aim is to investigate Lactobacillus acidophilus spp. and their isolated extracellular-derived proteins (LaEPs) on PJI-relevant Staphylococcus aureus, methicillin-resistant S. aureus, and Escherichia coli planktonic growth and biofilm formation in vitro. The effect of LaEPs on cultured macrophages and osteogenic, and adipogenic human bone marrow-derived mesenchymal stem cell differentiation is analyzed. Data show electrostatically-induced probiotic-pathogen species co-aggregation and pathogenic growth inhibition together with LaEP-induced biofilm prevention. LaEPs prime macrophages for enhanced microbial phagocytosis via cathepsin K, reduce lipopolysaccharide-induced DNA damage and receptor activator nuclear factor-kappa B ligand expression, and promote a reparative M2 macrophage morphology under chronic inflammatory conditions. LaEPs also significantly augment bone deposition while abating adipogenesis thus holding promise as a potential multimodal therapeutic strategy. Proteomic analyses highlight high abundance of lysyl endopeptidase, and urocanate reductase. Further, in vivo analyses are warranted to elucidate their role in the prevention and treatment of PJIs.

Effect of running exercise training on inflammatory mediators and cytokines expression in testicular tissue; effect of exercise intensity

The aim of this study is to investigate the impact of running exercise training protocols (ETPs) with varying intensities on inflammatory responses, with a specific focus on the interactions between inflammatory mediators, cytokines, and Leydig cell steroidogenic activity, as well as testosterone secretion. To this end, 24 Wistar rats were subdivided into sedentary control, low (LICT), moderate (MICT), and high (HICT) intensity continuous running ETP groups. After 8 weeks, the expression levels of Toll-like receptor-4 (TLR-4), nuclear factor-kappa-B (NF-KB), interleukin-6 (IL-6), interleukin-10 (IL-10), Tumor necrosis factor alpha (TNF-α), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and the testicular nitric oxide (NO) content were assessed and compared between groups. Moreover, the mean distributions of Leydig cells/mm2 of interstitial connective tissue, their steroidogenic activity, and serum level of testosterone were assessed. The LICT did not show any significant (p > 0.05) change in the expression levels of all aforementioned biomarkers. In contrast, both the MICT and HICT groups demonstrated a significant (p < 0.05) increase in the expression levels of TLR-4, NFK-B, IL-6, TNF-α, iNOS, and COX-2 at both the mRNA and protein levels. The testicular NO has increased in HICT and MICT groups. Despite a decrease in the distribution of Leydig cells in both the MICT and HICT groups, the HICT group exhibited a significant (p < 0.05) reduction in Leydig cell steroidogenic activity and serum testosterone levels. In conclusion, our findings revealed that ETPs can influence Leydig cell steroidogenic activity and testosterone secretion, contingent on their intensity. These effects are attributed to alterations in the expression levels of pro-inflammatory mediators and cytokines.

Broccoli Cultivated with Deep Sea Water Mineral Fertilizer Enhances Anti-Cancer and Anti-Inflammatory Effects of AOM/DSS-Induced Colorectal Cancer in C57BL/6N Mice

This study aimed to determine the alleviating effect of broccoli grown with deep sea water mineral (DSWM) fertilizer extracted from deep sea water on the development of colorectal cancer in C57BL/6N mice treated with AOM/DSS. Naturaldream Fertilizer Broccoli (NFB) cultured with deep sea water minerals (DSWM) showed a higher antioxidant effect and mineral content. In addition, orally administered NFB, showed a level of recovery in the colon and spleen tissues of mice compared with those in normal mice through hematoxylin and eosin (H&E) staining. Orally administered NFB showed the inhibition of the expression of inflammatory cytokine factors IL-1β, IL-6, TNF, IFN-γ, and IL-12 while increasing the expression of IL-10. Furthermore, the expression of inflammatory cytokines and NF-κB in the liver tissue was inhibited, and that of inflammatory enzymes, such as COX-2 and iNOS, was reduced. In the colon tissue, the expression of p53 and p21 associated with cell cycle arrest increased, and that of Bcl-2 associated with apoptosis decreased. Additionally, the expression of Bax, Bad, Bim, Bak, caspase 9, and caspase 3 increased, indicating enhanced activation of apoptosis-related factors. These results demonstrate that oral administration of broccoli cultivated using DSWM significantly restores spleen and colon tissues and simultaneously inhibits the NF-κB pathway while significantly decreasing cytokine expression. Moreover, by inducing cell cycle arrest and activating cell apoptosis, they also suggest alleviating AOM/DSS-induced colon cancer symptoms in C57BL/6N mice.

Fever-Range Hyperthermia Promotes Macrophage Polarization towards Regulatory Phenotype M2b

Fever-range hyperthermia (FRH) is utilized in chronic disease treatment and serves as a model for fever's thermal component investigation. Macrophages, highly susceptible to heat, play a pivotal role in various functions determined by their polarization state. However, it is not well recognized whether this process can be modulated by FRH. To address this, we used two different macrophage cell lines that were treated with FRH. Next, to define macrophage phenotype, we examined their functional surface markers CD80 and CD163, intracellular markers such as inducible nitric oxide synthase (iNOS), arginase-1 (Arg-1), and the expression of interleukin-10 (IL-10) and tumor necrosis factor α (TNF-α). Additionally, in FRH-treated cells, we analyzed an expression of Toll-like receptor 4 (TLR-4) and its role in macrophage polarization. We also checked whether FRH can switch the polarization of macrophages in pro-inflammatory condition triggered by lipopolysaccharide (LPS). FRH induced M2-like polarization, evident in increased CD163, IL-10, and Arg-1 expression. Notably, elevated COX-2, TNF-α, and TLR-4 indicated potential pro-inflammatory properties, suggesting polarization towards the M2b phenotype. Additionally, FRH shifted lipopolysaccharide (LPS)-induced M1 polarization to an M2-like phenotype, reducing antimicrobial molecules (ROS and NO). In summary, FRH emerged as a modulator favoring M2-like macrophage polarization, even under pro-inflammatory conditions, showcasing its potential therapeutic relevance.

Regulation of anti-inflammatory and antioxidant responses by methanol extract of Mikania cordata (Burm. f.) B. L. Rob. leaves via the inactivation of NF-κB and MAPK signaling pathways and activation of Nrf2 in LPS-induced RAW 264.7 macrophages

Mikania cordata (Burm. f.) B.L. Rob. has been traditionally used in tropical countries throughout Asia and Africa to treat gastric ulcers, dyspepsia, and dysentery. However, the mechanisms responsible for its anti-inflammatory and antioxidant activities are not fully understood. Therefore, this study sought to investigate the anti-inflammatory and antioxidant effects of methanol extracts of M. cordata (MMC) on inflammation and oxidative stress in lipopolysaccharide (LPS)-stimulated murine RAW 264.7 macrophages and elucidate its underlying regulatory mechanism. MMC significantly suppressed the production of nitric oxide (NO) and prostaglandin E2 (PGE2) in LPS-stimulated RAW 264.7 macrophages by downregulating the expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) at both the mRNA and protein levels. Moreover, MMC effectively reduced the mRNA expression levels and production of pro-inflammatory cytokines, including interleukin-6 (IL-6), IL-1β, and tumor necrosis factor-α (TNF-α). These suppressive effects of MMC on pro-inflammatory mediators and cytokines were mediated through the inhibition of transforming growth factor beta-activated kinase 1 (TAK1), which subsequently blocked the activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs). MMC also upregulated the nuclear factor erythroid-2-related factor 2 (Nrf2) by inducing the degradation of Kelch-like ECH-related protein 1 (Keap1), an Nrf2-specific E3 ligase. Accordingly, MMC enhanced Nrf2 target gene expression of anti-oxidative regulators such as heme oxygenase-1 (HO-1) and NAD(P)H quinone oxidoreductase 1 (NQO1). However, it had minimal effect on the DPPH radical scavenging capacity in vitro. Collectively, these findings demonstrate that MMC holds promise as a potential therapeutic agent for alleviating inflammation-related diseases and oxidative stress.

5-Aminolevulinic acid/sodium ferrous citrate improves the quality of heat-stressed bovine oocytes by reducing oxidative stress

A high temperature-humidity index during summer has deleterious effects on mitochondrial function, reducing oocyte developmental competence. 5-Aminolevulinic acid (5-ALA) and sodium ferrous citrate (SFC) are both known to support mitochondrial function and have strong anti-oxidant and anti-apoptotic activities. This study aimed to determine the mechanism of action of 5-ALA/SFC on oocyte quality. Bovine oocytes were collected from medium-sized follicles during summer (July-September, temperature-humidity index:76.6), cultured with 0, 1, 2, 4, and 8 µM 5-ALA with SFC at a molar ratio of 1:0.125, fertilized, and cultured for 10 days. The addition of 8/1 µM 5-ALA/SFC had a deleterious effect on oocyte cleavage rate in comparison with control oocytes, but did not affect the blastocyst rate, while 1/0.125 µM 5-ALA/SFC had a significantly higher increase in blastocyst rate than 8/1 µM 5-ALA/SFC. The addition of 1/0.125 and 2/0.25 µM 5-ALA/SFC improved oocyte quality by increasing the mitochondrial distribution pattern and metaphase-II oocytes, reducing reactive oxygen species and upregulating nuclear factor erythroid-2-related factor 2, heme oxygenase-1, and superoxide dismutase-1 in oocytes, and nuclear factor erythroid-2-related factor 2 and mitochondrial transcription factor A in cumulus cells. These results indicate that 1/0.125 and 2/0.25 µM 5-ALA/SFC may support oocyte quality and developmental competence and provide anti-oxidant actions in cumulus-oocyte complexes.

The Anti-Inflammatory Effect of Low Molecular Weight Fucoidan from Sargassum siliquastrum in Lipopolysaccharide-Stimulated RAW 264.7 Macrophages via Inhibiting NF-κB/MAPK Signaling Pathways

Brown seaweed is a rich source of fucoidan, which exhibits a variety of biological activities. The present study discloses the protective effect of low molecular weight fucoidan (FSSQ) isolated from an edible brown alga, Sargassum siliquastrum, on lipopolysaccharide (LPS)-stimulated inflammatory responses in RAW 264.7 macrophages. The findings of the study revealed that FSSQ increases cell viability while decreasing intracellular reactive oxygen species production in LPS-stimulated RAW 264.7 macrophages dose-dependently. FSSQ reduced the iNOS and COX-2 expression, inhibiting the NO and prostaglandin E2 production. Furthermore, mRNA expression of IL-1β, IL-6, and TNF-α was downregulated by FSSQ via modulating MAPK and NF-κB signaling. The NLRP3 inflammasome protein complex, including NLRP3, ASC, and caspase-1, as well as the subsequent release of pro-inflammatory cytokines, such as IL-1β and IL-18, release in LPS-stimulated RAW 264.7 macrophages was inhibited by FSSQ. The cytoprotective effect of FSSQ is indicated via Nrf2/HO-1 signaling activation, which is considerably reduced upon suppression of HO-1 activity by ZnPP. Collectively, the study revealed the therapeutic potential of FSSQ against inflammatory responses in LPS-stimulated RAW 264.7 macrophages. Moreover, the study suggests further investigations on commercially viable methods for fucoidan isolation.

Effects of Oral 5-Aminolevulinic Acid on Lipopolysaccharide-Induced Ocular Inflammation in Rats

This study aimed to investigate the anti-inflammatory effect of 5-aminolevulinic acid (5-ALA) on endotoxin-induced uveitis (EIU) in rats. EIU was induced in male Sprague Dawley rats by the subcutaneous injection of lipopolysaccharide (LPS). During LPS injection, 5-ALA diluted with saline was administered via gastric gavage. After 24 h, clinical scores were assessed after which aqueous humor (AqH) samples were obtained. The number of infiltrating cells, protein concentration, and levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), nitric oxide (NO), and prostaglandin E2 (PGE2) in AqH were measured. For histological examination, both eyes of some rats were enucleated. In vitro, a mouse macrophage cell line (RAW264.7 cells) was stimulated by LPS with or without 5-ALA. Western blot was used to analyze the expression of inducible NO synthase (iNOS) and cyclooxygenase-2. 5-ALA suppressed the EIU clinical scores, infiltrating cell number, and protein concentration while improving the histopathologic scores. In particular, 100 mg/kg 5-ALA reduced the concentrations of NO, PGE2, TNF-α, and IL-6 in AqH, similar to 1 mg/kg prednisolone. In addition, 5-ALA suppressed iNOS upregulation in LPS-stimulated RAW264.7 cells. Therefore, 5-ALA has an anti-inflammatory effect on EIU through the inhibition of the upregulation of inflammatory mediators.

Cerium oxide nanozymes confer a cytoprotective and bio-friendly surface micro-environment to methacrylate based oro-facial prostheses

Poly-(methyl methacrylate) (PMMA) is the preferred biomaterial for orofacial prostheses used for the rehabilitation of naso-palatal defects. However, conventional PMMA has limitations determined by the complexity of the local microbiota and the friability of oral mucosa adjacent to these defects. Our purpose was to develop a new type of PMMA, i-PMMA, with good biocompatibility and better biological effects such as higher resistance to microbial adhesion of multiple species and enhanced antioxidant effect. The addition of cerium oxide nanoparticles to PMMA using a mesoporous nano-silica carrier and polybetaine conditioning, resulted in an increased release of cerium ions and enzyme mimetic activity, without tangible loss of mechanical properties. Ex vivo experiments confirmed these observations. In stressed human gingival fibroblasts, i-PMMA reduced the levels of reactive oxygen species and increased the expression of homeostasis-related proteins (PPARg, ATG5, LCI/III). Furthermore, i-PMMA increased the levels of expression of superoxide dismutase and mitogen-activated protein kinases (ERK and Akt), and cellular migration. Lastly, we demonstrated the biosafety of i-PMMA using two in vivo models: skin sensitization assay and oral mucosa irritation test, respectively. Therefore, i-PMMA offers a cytoprotective interface that prevents microbial adhesion and attenuates oxidative stress, thus supporting physiological recovery of the oral mucosa.

Dietary methionine restriction alleviates oxidative stress and inflammatory responses in lipopolysaccharide-challenged broilers at early age

In this study, we investigated the effect of dietary methionine restriction (MR) on the antioxidant function and inflammatory responses in lipopolysaccharide (LPS)-challenged broilers reared at high stocking density. A total of 504 one-day-old male Arbor Acre broiler chickens were randomly divided into four treatments: 1) CON group, broilers fed a basal diet; 2) LPS group, LPS-challenged broilers fed a basal diet; 3) MR1 group, LPS-challenged broilers fed a methionine-restricted diet (0.3% methionine); and 4) MR2 group, LPS-challenged broilers fed a methionine-restricted diet (0.4% methionine). LPS-challenged broilers were intraperitoneally injected with 1 mg/kg body weight (BW) of LPS at 17, 19, and 21 days of age, whereas the CON group was injected with sterile saline. The results showed that: LPS significantly increased the liver histopathological score (p < 0.05); LPS significantly decreased the serum total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activity at 3 h after injection (p < 0.05); the LPS group had a higher content of Interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF)-α, but a lower content of IL-10 than the CON group in serum (p < 0.05). Compared with the LPS group, the MR1 diet increased catalase (CAT), SOD, and T-AOC, and the MR2 diet increased SOD and T-AOC at 3 h after injection in serum (p < 0.05). Only MR2 group displayed a significantly decreased liver histopathological score (p < 0.05) at 3 h, while MR1 and MR2 groups did so at 8 h. Both MR diets significantly decreased serum LPS, CORT, IL-1β, IL-6, and TNF-α contents, but increased IL-10 content (p < 0.05). Moreover, the MR1 group displayed significantly increased expression of nuclear factor erythroid 2-related factor 2 (Nrf2), CAT, and GSH-Px at 3 h; the MR2 group had a higher expression of Kelch-like ECH-associated protein 1 (Keap1), SOD, and GSH-Px at 8 h (p < 0.05). In summary, MR can improve antioxidant capacity, immunological stress, and liver health in LPS-challenged broilers. The MR1 and MR2 groups experienced similar effects on relieving stress; however, MR1 alleviated oxidative stress more rapidly. It is suggested that precise regulation of methionine levels in poultry with stress may improve the immunity of broilers, reduce feed production costs, and increase production efficiency in the poultry industry.

Adverse Effect of Blue Light on DNA Integrity Is Accelerated by 5-Aminolevulinic Acid in HaCaT Human Keratinocyte Cells and B16F1 Murine Melanoma Cells

Several studies have suggested the potential benefits of 5-aminolevulinic acid (5-ALA)-based photodynamic therapy (PDT). 5-ALA is a precursor of heme, which generates reactive oxygen species (ROS) following photoirradiation. Some reports indicate that blue light induces intracellular ROS production. In the present study, we elucidated the effects of blue light and 5-ALA on DNA integrity in B16F1 murine melanoma and human keratinocyte HaCaT cells using a variety of comet assay techniques. Co-treatment with blue light and 5-ALA significantly decreased cell viability in both cell lines. A neutral comet assay was performed to assess DNA double-strand break (DSB) formation and blue light and 5-ALA caused DSBs. We also performed an alkali comet assay to detect single-strand breaks (SSB) and alkali labile sites (ALS). The results indicated that 5-ALA accelerated blue light-induced SSB formation. In addition, modified comet assays were done using two types of enzymes to evaluate oxidative DNA damages. The results indicated that blue light and 5-ALA generated oxidized purine and pyrimidines in both cell lines. In summary, co-treatment with 5-ALA and photoirradiation may cause unexpected DNA damage in cells and tissues.

Dimethyl itaconate reprograms neurotoxic to neuroprotective primary astrocytes through the regulation of NLRP3 inflammasome and NRF2/HO-1 pathways

The activation of neurotoxic reactive astrocytes contributes to the pathogenesis of many neurodegenerative diseases. Itaconate, a product of cellular metabolism, is released from activated macrophage/microglia and has been shown to regulate inflammatory responses in several mammalian cells. This study was designed to investigate the impact of cell-permeable dimethyl itaconate (DI) on reactive astrocyte-dependent neurotoxicity. Primary murine astrocyte cells were isolated and stimulated with lipopolysaccharide (LPS) to generate reactive astrocytes. Treating these activated cells with DI was able to diminish the neurotoxic phenotype of reactive astrocytes, as we found reduced LPS-induced Nod-like receptor protein 3 (NLRP3) inflammasome activation and interleukin-1β (IL-1β) secretion. DI reduced the level of inflammasome components, attenuated inflammasome assembly and subsequently reduced caspase-1 cleavage and IL-1β levels. Additionally, DI attenuated nuclear factor-kappa B (NF-κB) phosphorylation in LPS-activated astrocytes and also protected astrocytes from LPS-induced cytotoxicity, including a lowering of Bax and caspase3. DI-treated reactive astrocytes showed an elevated GSH/GSSG ratio and improved antioxidant defense factors including catalase and superoxide dismutase, while lipid peroxidation was reduced. We found that DI activated the nuclear factor 2 (NRF2) and heme oxygenase-1 (HO-1) pathway in astrocytes and thereby potentially control redox-regulation and the inflammatory state of astrocytes. Collectively, these results indicate the neuroprotective role of DI by reprogramming astrocytes from neurotoxic A1 to neuroprotective A2 states and thereby reveal a novel potential strategy for the treatment of neurodegenerative diseases.

Protection against Oxidative Stress-Induced Apoptosis by Fermented Sea Tangle (Laminaria japonica Aresch) in Osteoblastic MC3T3-E1 Cells through Activation of Nrf2 Signaling Pathway

The purpose of the present study was to explore the efficacy of fermented extract of sea tangle (Laminaria japonica Aresch, FST) with Lactobacillus brevis on DNA damage and apoptosis in hydrogen peroxide (H₂O₂)-stimulated osteoblastic MC3T3-E1 cells and clarify related signaling pathways. Our results showed that exposure to FST significantly improved cell viability, inhibited apoptosis, and suppressed the generation of reactive oxygen species (ROS) in H₂O₂-stimulated cells. In addition, H₂O₂ triggered DNA damage in MC3T3-E1 cells was markedly attenuated by FST pretreatment. Moreover, H₂O₂-induced mitochondrial dysfunctions associated with apoptotic events, including loss of mitochondrial membrane potential (MMP), decreased Bcl-2/Bcl-2 associated x-protein (Bax) ratio, and cytosolic release of cytochrome c, were reduced in the presence of FST. FST also diminished H₂O₂-induced activation of caspase-3, which was associated with the ability of FST to protect the degradation of poly (ADP-ribose) polymerase. Furthermore, FST notably enhanced nuclear translocation and phosphorylation of nuclear factor erythroid 2-related factor 2 (Nrf2) in the presence of H₂O₂ with concomitant upregulation of heme oxygenase-1 (HO-1) expression. However, artificial blockade of this pathway by the HO-1 inhibitor, zinc protoporphyrin IX, greatly abolished the protective effect of FST against H₂O₂-induced MC3T3-E1 cell injury. Taken together, these results demonstrate that FST could protect MC3T3-E1 cells from H₂O₂-induced damage by maintaining mitochondrial function while eliminating ROS along with activation of the Nrf2/HO-1 antioxidant pathway.

Anti-Inflammatory Effect of Auranofin on Palmitic Acid and LPS-Induced Inflammatory Response by Modulating TLR4 and NOX4-Mediated NF-κB Signaling Pathway in RAW264.7 Macrophages

Chronic inflammation, which is promoted by the production and secretion of inflammatory mediators and cytokines in activated macrophages, is responsible for the development of many diseases. Auranofin is a Food and Drug Administration-approved gold-based compound for the treatment of rheumatoid arthritis, and evidence suggests that auranofin could be a potential therapeutic agent for inflammation. In this study, to demonstrate the inhibitory effect of auranofin on chronic inflammation, a saturated fatty acid, palmitic acid (PA), and a low concentration of lipopolysaccharide (LPS) were used to activate RAW264.7 macrophages. The results show that PA amplified LPS signals to produce nitric oxide (NO) and various cytokines. However, auranofin significantly inhibited the levels of NO, monocyte chemoattractant protein-1, and pro-inflammatory cytokines, such as interleukin (IL)-1β, tumor necrosis factor-α, and IL-6, which had been increased by co-treatment with PA and LPS. Moreover, the expression of inducible NO synthase, IL-1β, and IL-6 mRNA and protein levels increased by PA and LPS were reduced by auranofin. In particular, the upregulation of NADPH oxidase (NOX) 4 and the translocation of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) induced by PA and LPS were suppressed by auranofin. The binding between the toll-like receptor (TLR) 4 and auranofin was also predicted, and the release of NO and cytokines was reduced more by simultaneous treatment with auranofin and TLR4 inhibitor than by auranofin alone. In conclusion, all these findings suggested that auranofin had anti-inflammatory effects in PA and LPS-induced macrophages by interacting with TLR4 and downregulating the NOX4-mediated NF-κB signaling pathway.