Dunaliella salina alga extract inhibits the production of interleukin-6, nitric oxide, and reactive oxygen species by regulating nuclear factor-κB/Janus kinase/signal transducer and activator of transcription in virus-infected RAW264.7 cells

Targeted screening of multiple anti-inflammatory components from Chrysanthemi indici Flos by ligand fishing with affinity UF-LC/MS

Chrysanthemi indic Flos (CIF) has been commonly consumed for the treatment of inflammation and related skin diseases. However, the potential bioactive components responsible for its anti-inflammatory and sensitive skin (SS) improvement activities, and the correlated mechanisms of action still remain unknown. In this work, it was firstly found that the CIF extract (CIFE) displayed arrestive free radical scavenging activity on DPPH and ABTS radicals, with no significant difference with positive control Trolox (p > 0.05). Then, compared to the negative group, CIFE markedly decreased the productions of the pro-inflammatory cytokines (IL-1β, IL-6, PEG2, TNF-α, IFN-γ, NO) in LPS induced RAW264.7 cells in a dose-dependent manner (p < 0.01). Besides, CIFE strongly inhibited the COX-2 and hyaluronidase (HAase) with the IC50 values of 1.06 ± 0.01 μg/mL and 12.22 ± 0.39 μg/mL, indicating higher inhibitory effect than positive control of aspirin of 6.33 ± 0.05 μg/mL (p < 0.01), and comparable inhibitory effect with indometacin of 0.60 ± 0.03 μg/mL, and ascorbic acid of 11.03 ± 0.41 μg/mL (p > 0.05), respectively. Furthermore, kinetic assays with Lineweaver-Burk plot (Michaelis Menten equation) suggested that CIFE reversibly inhibited the COX-2 and HAase, with a mixed characteristics of competitive and non-competitive inhibition. Thereafter, multi-target affinity ultrafiltration liquid chromatography-mass spectrometry (UF-LC/MS) method was employed to fast fish out the potential COX-2 and HAase in CIFE. Herein, 13 components showed various affinity binding degrees to the COX-2 and HAase, while those components with relative binding affinity (RBA) value higher than 3.0, such as linarin and chlorogenic acid isomers, were deemed to be the most bioactive components for the anti-inflammatory and SS improvement activities of CIFE. Finally, the interaction mechanism, including binding energy, inhibition constant, docking sites, and the key amino acids involved in hydrogen bonds between the potential ligands and COX-2/HAase were simulated and confirmed with the molecule docking analysis. In summary, this study showcased the prominent anti-inflammatory and SS improvement activities of CIF, which would provide further insights on this functional medicinal plant to be a natural anti-SS remedy.

Innovative Bioactive Products with Medicinal Value from Microalgae and Their Overall Process Optimization through the Implementation of Life Cycle Analysis-An Overview

Microalgae are being recognized as valuable sources of bioactive chemicals with important medical properties, attracting interest from multiple industries, such as food, feed, cosmetics, and medicines. This review study explores the extensive research on identifying important bioactive chemicals from microalgae, and choosing the best strains for nutraceutical manufacturing. It explores the most recent developments in recovery and formulation strategies for creating stable, high-purity, and quality end products for various industrial uses. This paper stresses the significance of using Life Cycle Analysis (LCA) as a strategic tool with which to improve the entire process. By incorporating LCA into decision-making processes, researchers and industry stakeholders can assess the environmental impact, cost-effectiveness, and sustainability of raw materials of several approaches. This comprehensive strategy will allow for the choosing of the most effective techniques, which in turn will promote sustainable practices for developing microalgae-based products. This review offers a detailed analysis of the bioactive compounds, strain selection methods, advanced processing techniques, and the incorporation of LCA. It will serve as a valuable resource for researchers and industry experts interested in utilizing microalgae for producing bioactive products with medicinal properties.

Suppression of NF-κB signaling by Pseudorabies virus DNA polymerase processivity factor UL42 via recruiting SOCS1 to promote the ubiquitination degradation of p65

The NF-κB pathway is a critical signaling involved in the regulation of the inflammatory and innate immune responses. Previous studies have shown that Pseudorabies Virus (PRV), a porcine alpha herpesvirus, could lead to the phosphorylation and nucleus translocation of p65 while inhibiting the expression of NF-κB-dependent inflammatory cytokines, which indicated that there may be unknown mechanisms downstream of p65 that downregulate the activation of NF-κB signaling. Here, we found that PRV DNA polymerase factor UL42 inhibited TNFα-, LPS-, IKKα-, IKKβ-, and p65-mediated transactivation of NF-κB signaling, which demonstrated UL42 worked either at or downstream of p65. In addition, it was found that the DNA-binding activity of UL42 was required for inhibition of NF-κB signaling. Importantly, it was revealed that UL42 could induce the ubiquitination degradation of p65 by upregulating the suppressor of cytokine signaling 1 (SOCS1). Additionally, it was found that UL42 could promote the K6/K29-linked ubiquitination of p65. Finally, knockdown of SOCS1 attenuated the replication of PRV and led to a significant increase of the inflammatory cytokines. Taken together, our findings uncovered a novel mechanism that PRV-UL42 could upregulated SOCS1 to promote the ubiquitination degradation of p65 to prevent excessive inflammatory response during PRV infection.

Ameliorative effects of Dunaliella salina microalgae on nanoparticle (ZnO NPs)-induced toxicity in fish

Dunaliella salina (D. salina) is a well-known microalga that contains considerable amounts of nutritious and medicinal bioactive components. This work studied the modulatory role of D. salina against zinc oxide nanoparticle (ZnO NPs)-induced neurotoxic effects in adult zebrafish. Fishes were subjected to 0.69 mg L-1 (1/5th 96-h LC50) for 4 weeks; then, fishes were supplemented with D. salina in the diet for 2 weeks at two levels (15 and 30%). Exposure to ZnO NPs induced a significant increase in the levels of reactive oxygen species (ROS), hydrogen peroxide (H2O2), malondialdehyde (MDA), and 8-hydroxy-2-deoxyguanosine (8-OH-dG) while accompanied with downregulation of antioxidant genes in the brain of exposed fishes. Brain neurochemistry and enzyme activities were also altered following ZnO NP exposure. ZnO NPs significantly reduced the neurotransmitters and acetylcholinesterase (AchE) activity while increasing Alzheimer's disease-related proteins and inflammatory response via upregulation of tumor necrosis factor (TNF-α). Additionally, ZnO NPs increased the indices of brain's DNA oxidative damage, increasing brain tissue's metallothionein (MT) and zinc residues. ZnO NPs upregulated the transcription patterns of apoptosis-related genes (casp3 and p53). D. salina dietary co-supplementation with ZnO NPs alleviated the ZnO NPsZnO NP-induced neuro-oxidative damages by lowering the lipid, DNA damage, and inflammatory biomarkers. Besides, D. salina alleviating responses were linked with increasing the levels of the assessed antioxidants. Conclusively, D. salina dietary supplementation induced potential alleviating effects of the ZnO NP-induced neurotoxicity in adult zebrafish.

Coelonin protects against PM2 .5 -induced macrophage damage via suppressing TLR4/NF-κB/COX-2 signaling pathway and NLRP3 inflammasome activation in vitro

One of the important monitoring indicators of the air pollution is atmospheric fine particulate matter (PM_2.5 ), which can induce lung inflammation after inhalation. Coelonin can alleviate PM_2.5 -induced macrophage damage through anti-inflammation. However, its molecular mechanism remains unclear. We hypothesized that macrophage damage may involve the release of inflammatory cytokines, activation of inflammatory pathways, and pyrosis induced by inflammasome. In this study, we evaluated the anti-inflammation activity of coelonin in PM_2.5 -induced macrophage and its mechanism of action. Nitric oxide (NO) and reactive oxygen species (ROS) production were measured by NO Assay kit and dichlorofluorescein-diacetate (DCFH-DA), and apoptosis were measured by Flow cytometry and TUNEL staining. The concentration of inflammatory cytokines production was measured with cytometric bead arrays and ELISA kits. The activation of NF-κB signaling pathway and NLRP3 inflammasome were measured by immunofluorescence, quantitative reverse transcription-polymerase chain reaction and western blot. As expected, coelonin pretreatment reduced NO production significantly as well as alleviated cell damage by decreasing ROS and apoptosis. It decreased generation of interleukin (IL)-6 and tumor necrosis factor (TNF)-α in PM_2.5 -induced RAW264.7 and J774A.1 cells. Moreover, coelonin markedly inhibited upregulating the expression of toll-like receptor (TLR)4 and cyclo-oxygenase (COX)-2, blocked activation of p-nuclear factor-kappa B (NF-κB) signaling pathway, and suppressed expression of NLRP3 inflammasome, ASC, GSDMD, IL-18 and IL-1β. In conclusion, the results showed that coelonin could protect against PM_2.5 -induced macrophage damage via suppressing TLR4/NF-κB/COX-2 signaling pathway and NLRP3 inflammasome activation in vitro.

Dunaliella salina Alga Protects against Myocardial Ischemia/Reperfusion Injury by Attenuating TLR4 Signaling

Myocardial ischemia/reperfusion (I/R) injury is marked by rapid increase in inflammation and not only results in myocardial apoptosis but also compromises the myocardial function. Dunaliella salina (D. salina), a halophilic unicellular microalga, has been used as a provitamin A carotenoid supplement and color additive. Several studies have reported that D. salina extract could attenuate lipopolysaccharides-induced inflammatory effects and regulate the virus-induced inflammatory response in macrophages. However, the effects of D. salina on myocardial I/R injury remain unknown. Therefore, we aimed to investigate the cardioprotection of D. salina extract in rats subjected to myocardial I/R injury that was induced by occlusion of the left anterior descending coronary artery for 1 h followed by 3 h of reperfusion. Compared with the vehicle group, the myocardial infarct size significantly decreased in rats that were pre-treated with D. salina. D. salina significantly attenuated the expressions of TLR4, COX-2 and the activity of STAT1, JAK2, IκB, NF-κB. Furthermore, D. salina significantly inhibited the activation of caspase-3 and the levels of Beclin-1, p62, LC3-I/II. This study is the first to report that the cardioprotective effects of D. salina may mediate anti-inflammatory and anti-apoptotic activities and decrease autophagy through the TLR4-mediated signaling pathway to antagonize myocardial I/R injury.

Dunaliella salina Microalga Restores the Metabolic Equilibrium and Ameliorates the Hepatic Inflammatory Response Induced by Zinc Oxide Nanoparticles (ZnO-NPs) in Male Zebrafish

Microalgae are rich in bioactive compounds including pigments, proteins, lipids, polyunsaturated fatty acids, carbohydrates, and vitamins. Due to their non-toxic and nutritious characteristics, these are suggested as important food for many aquatic animals. Dunaliella salina is a well-known microalga that accumulates valuable amounts of carotenoids. We investigated whether it could restore the metabolic equilibrium and mitigate the hepatic inflammation induced by zinc oxide nanoparticles (ZnO-NPs) using male zebrafish which were exposed to 1/5^th 96 h-LC₅₀ for 4 weeks, followed by dietary supplementation with D. salina at two concentrations (15% and 30%) for 2 weeks. Collectively, ZnO-NPs affected fish appetite, whole body composition, hepatic glycogen and lipid contents, intestinal bacterial and Aeromonas counts, as well as hepatic tumor necrosis factor- α (TNF-α). In addition, the mRNA expression of genes related to gluconeogenesis (pck1, gys2, and g6pc3), lipogenesis (srepf1, acaca, fasn, and cd36), and inflammatory response (tnf-α, tnf-β, nf-kb2) were modulated. D. salina reduced the body burden of zinc residues, restored the fish appetite and normal liver architecture, and mitigated the toxic impacts of ZnO-NPs on whole-body composition, intestinal bacteria, energy metabolism, and hepatic inflammatory markers. Our results revealed that the administration of D. salina might be effective in neutralizing the hepatotoxic effects of ZnO-NPs in the zebrafish model.

Sophora subprostrate polysaccharide regulates histone acetylation to inhibit inflammation in PCV2-infected murine splenic lymphocytes in vitro and in vivo

Porcine circovirus type 2 (PCV2) has caused large economic losses in the swine industry worldwide; therefore, research on relevant therapeutic medicines is still urgently needed. To define the relationship between histone acetylation and inflammation induced by PCV2, we investigated whether traditional Chinese medicinal polysaccharides could alleviate viral infection by regulating histone acetylation. In this study, Sophora subprostrate polysaccharide (SSP)-treated PCV2-infected murine splenic lymphocytes in vitro and murine spleen in vivo were used to explore the regulatory effects of SSP on inflammation and histone acetylation caused by PCV2. SSP at different concentrations significantly reduced the secretion levels of the proinflammatory cytokines TNF-α and IL-6, the activity of COX-2, the mRNA expression levels of TNF-α, IL-6, iNOS and COX-2 and the protein expression levels of iNOS and COX-2 but promoted the secretion and mRNA expression levels of IL-10. Furthermore, the different concentrations of SSP significantly regulated the activity of histone acetylase (HAT) and the mRNA expression of HAT1, increased the activity of histone deacetylase (HDAC) and the mRNA expression of HDAC1 and reduced the protein expression levels of Ac-H3 and Ac-H4. Overall, SSP inhibited inflammation in PCV2-infected murine splenic lymphocytes by regulating histone acetylation in vitro and in vivo, thus playing an important role in PCV2 infection.

Gelidiella acerosa Compounds Target NFκB Cascade in Lung Adenocarcinoma

In carcinogenesis, increased metabolism, abnormal functioning of mitochondria, peroxisomes, aberrant cell signaling, and prolonged inflammation can result in the overproduction of reactive oxygen species (ROS). In turn, excess ROS can upregulate the expression of various signaling pathways including the MAP kinase, PI3K/Akt, and NFκB cascades in cancer. The constitutive expression of NFκB causes drug resistance in lung cancer. Hence, drugs that can enhance the antioxidant activity of enzymes and regulate the NFκB activity are of prime target to manage the drug resistance and inflammation in cancer. This study evaluated the effect of compounds present in ethyl acetate extract of Gelidiella acerosa on inflammation and on antioxidant enzymes in lung cancer. The anti-inflammatory activity was determined under in silico and in vitro conditions. The in silico analysis showed that the phyto-constituents of G. acerosa inhibit the IKBα-NFκB-p65-p50 complex in a similar way as that of doxorubicin and dexamethasone. Similarly, G. acerosa treatment enhanced the efficiency of antioxidant enzymes peroxidases and superoxide dismutase in A549 lung cancer cells. Furthermore, the results of in vitro analysis showed that G. acerosa can decrease the activation of NFκB and production of pro-inflammatory cytokines and upregulate the expression of IL 10. As inflammation causes cancer progression, the inhibition of inflammation inhibits tumorigenesis. Hence, based on the results of the study, it can be concluded that G. acerosa exerts anti-inflammatory activity by decreasing the expression of NFκB cascade and moreover, the phyto-constituents of G. acerosa may have the potential to regulate the inflammatory response.

Anti-inflammatory effects of Flos Lonicerae Japonicae Water Extract are regulated by the STAT/NF-κB pathway and HO-1 expression in Virus-infected RAW264.7 cells

This study examined the effect of the Flos Lonicerae Japonicae water extract (FLJWE), chlorogenic acid, and luteolin on pseudorabies virus (PRV)-induced inflammation in RAW264.7 cells and elucidated related molecular mechanisms. The results revealed that FLJWE and luteolin, but not chlorogenic acid, inhibited the production of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and inflammatory cytokines in PRV-infected RAW 264.7 cells. We found that the FLJWE and luteolin suppressed nuclear factor (NF)-κB activation by inhibiting the phosphorylation of signal transducer and activator of transcription 1 and 3 (STAT1 and STAT3, respectively). Moreover, the FLJWE significantly upregulated the expression of pNrf2 and its downstream target gene heme oxygenase-1 (HO-1). Our data indicated that FLJWE and luteolin reduced the expression of proinflammatory mediators and inflammatory cytokines, such as COX-2 and iNOS, through the suppression of the JAK/STAT1/3-dependent NF-κB pathway and the induction of HO-1 expression in PRV-infected RAW264.7 cells. The findings indicate that the FLJWE can be used as a potential antiviral agent.

Ethyl acetate fraction of flavonoids from Polygonum hydropiper L. modulates pseudorabies virus-induced inflammation in RAW264.7 cells via the nuclear factor-kappa B and mitogen-activated protein kinase pathways

Pseudorabies virus (PRV) infection leads to severe inflammatory responses and tissue damage, and many natural herbs exhibit protective effects against viral infection by modulating the inflammatory response. An ethyl acetate fraction of flavonoids from Polygonum hydropiper L. (FEA) was prepared through ethanol extraction and ethyl acetate fractional extraction. An inflammatory model was established in RAW264.7 cells with PRV infection to evaluate the anti-inflammatory activity of FEA by measuring cell viability, nitric oxide (NO) production, reactive oxygen species (ROS) release, and mRNA expression of inflammatory factors, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). Its functional mechanism was investigated by analyzing the phosphorylation and nuclear translocation of key proteins in the nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. Our findings indicate that PRV induced inflammatory responses in RAW264.7 cells, and the responses were similar to that in lipopolysaccharide (LPS)-stimulated cells. FEA significantly suppressed NO synthesis and down-regulated both expression and secretion of COX-2, iNOS, and inflammatory cytokines (P<0.05 or P<0.01). FEA also reduced NF-κB p65 translocation into the nucleus and decreased MAPK phosphorylation, indicating that the NF-κB/MAPK signaling pathway may be closely related to the inflammatory response during viral infection. The findings suggested the potential pharmaceutical application of FEA as a natural product that can treat viral infections due to its ability to mitigate inflammatory responses.

Effects of different abiotic stresses on carotenoid and fatty acid metabolism in the green microalga Dunaliella salina Y6

Purpose

Under different abiotic-stress conditions, the unicellular green microalga Dunaliella salina accumulates large amounts of carotenoids which are accompanied by fatty acid biosynthesis. Carotenoids and fatty acids both possess long carbon backbones; however, the relationship between carotenoid and fatty acid metabolism is controversial and remains poorly understood in microalgae.

Methods

In this study, we investigated the growth curves and the β-carotene, lutein, lipid, and fatty acid contents of D. salina Y6 grown under different abiotic-stress conditions, including high light, nitrogen depletion, and high salinity.

Results

Both high-salinity and nitrogen-depleted conditions significantly inhibited cell growth. Nitrogen depletion significantly induced β-carotene accumulation, whereas lutein production was promoted by high light. The accumulation of lipids did not directly positive correlate with β-carotene and lutein accumulation under the three tested abiotic-stress conditions, and levels of only a few fatty acids were increased under specific conditions.

Conclusion

Our data indicate that cellular β-carotene accumulation in D. salina Y6 positive correlates with accumulation of specific fatty acids (C16:0, C18:3n3, C14:0, and C15:0) rather than with total fatty acid content under different abiotic stress conditions.

Intestinal injury can be effectively prevented by Dunaliella salina in gamma irradiated rats

Dunaliella salina (D. salina) is one of the most common microalgae that is used as human food. It is isolated from the salty lakes in El-Fayoum and Lake of Bardawil-Sinai in Egypt and can withstand very high concentrations of salt: The potentiality of D. salina, a unicellular biflagellate green alga to protect against intestinal injury induced after radiation exposure was studied. D. salina was given orally in doses of 100 and 200 mg/kg to male Wistar rats for 5 days before exposure to 6 Gray (Gy) gamma radiation and continued for a further two days. Rats were sacrificed 24 h later and intestinal segments were dissected out. One segment was examined histologically and another was used to prepare homogenates to assess relevant biochemical parameters reflecting intestinal injury. Radiation exposure led to a rise in the histological damage score, an increase in tissue tumor necrosis factor (TNF-α), interleukin (IL-1β) and thiobarbituric acid reactive substances (TBARS) but a reduction in tissue reduced glutathione (GSH) and in serum citrulline. Pretreatment with either dose of D. salina effectively reduced the severity of intestinal mucositis induced by gamma radiation.

SOCS and Herpesviruses, With Emphasis on Cytomegalovirus Retinitis

Suppressor of cytokine signaling (SOCS) proteins provide selective negative feedback to prevent pathogeneses caused by overstimulation of the immune system. Of the eight known SOCS proteins, SOCS1 and SOCS3 are the best studied, and systemic deletion of either gene causes early lethality in mice. Many viruses, including herpesviruses such as herpes simplex virus and cytomegalovirus, can manipulate expression of these host proteins, with overstimulation of SOCS1 and/or SOCS3 putatively facilitating viral evasion of immune surveillance, and SOCS suppression generally exacerbating immunopathogenesis. This is particularly poignant within the eye, which contains a diverse assortment of specialized cell types working together in a tightly controlled microenvironment of immune privilege. When the immune privilege of the ocular compartment fails, inflammation causing severe immunopathogenesis and permanent, sight-threatening damage may occur, as in the case of AIDS-related human cytomegalovirus (HCMV) retinitis. Herein we review how SOCS1 and SOCS3 impact the virologic, immunologic, and/or pathologic outcomes of herpesvirus infection with particular emphasis on retinitis caused by HCMV or its mouse model experimental counterpart, murine cytomegalovirus (MCMV). The accumulated data suggests that SOCS1 and/or SOCS3 can differentially affect the severity of viral diseases in a highly cell-type-specific manner, reflecting the diversity and complexity of herpesvirus infection and the ocular compartment.