Antioxidant and Anti-inflammatory Activities of Different Solvent Extracts from Ipomoea pes-caprae (L.) R. Br. in Lipopolysaccharide Stimulated RAW 264.7 Macrophages

The oxidative stress and inflammatory environment trigger an unhealthy circle, which can lead to various inflammatory diseases. Ipomoea pes-caprae, a traditional medicine mangrove plant, posed many pharmacological activities, including antioxidant, anti-inflammatory and anticancer effects. However, the possible mechanisms involved in Ipomoea pes-caprae are still unclear. This study aimed to investigate the antioxidant and anti-inflammatory effects of different solvent extracts from Ipomoea pes-caprae on lipopolysaccharide (LPS) stimulated macrophages. Three different solvent gradients were prepared orderly from non-polar to polar: hexane (Hex), supercritical fluid extraction using carbon dioxide plus EtOH as co-solvent (SCO2) and ethanol (EtOH). All 3 extracts were screened for the cytotoxicity on RAW264.7 cells by MTT assay. The non-toxic doses were investigated for reactive oxygen species (ROS) scavenging by DPPH and DCFH-DA assays and evaluated their anti-inflammatory activities via inhibition against LPS-induced nitric oxide (NO), prostaglandin E2 (PGE2), inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) mRNA expression. All 3 extracts (25 - 50 μg/mL) exhibited DPPH scavenging and reduced intracellular ROS level in the order of SCO2 > EtOH > Hex. Further, these extracts suppressed NO and PGE2 production by regulating iNOS and COX-2 mRNA expression in the order of SCO2 > Hex > EtOH. Additionally, their inhibitory effects were in a similar pattern as the standard drugs L-NAME and celecoxib. These findings support the traditional use of Ipomoea pes-caprae in treating inflammatory diseases due to its attenuation of inflammation in activated macrophage. Also, a wide range of secondary metabolites in unique ecology may be useful as one of the alternative therapies for inflammatory diseases. HIGHLIGHTS Ipomoea pes-caprae employ a sort of secondary metabolites under stressful high salt conditions with benefit for new drug discoveries SCO2 extract exhibited the strongest activities in the LPS-induced ROS and PGE2 production These bioactive compounds contained in Ipomoea pes-caprae confirm the traditional use against jellyfish stings and may targeting inflammatory pathways GRAPHICAL ABSTRACT

Ibuprofen-Loaded Chitosan–Lipid Nanoconjugate Hydrogel with Gum Arabic: Green Synthesis, Characterisation, In Vitro Kinetics Mechanistic Release Study and PGE2 Production Test

Ibuprofen is a well-known non-steroidal anti-inflammatory (NSAID) medicine that is often used to treat inflammation in general. When given orally, it produces gastrointestinal issues which lead to lower patient compliance. Ibuprofen transdermal administration improves both patient compliance and the efficacy of the drug. Nanoconjugation hydrogels were proposed as a controlled transdermal delivery tool for ibuprofen. Six formulations were prepared using different compositions including chitosan, lipids, gum arabic, and polyvinyl alcohol, through ionic interaction, maturation, and freeze–thaw methods. The formulations were characterised by size, drug conjugation efficiency, differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR). Further analysis of optimised hydrogels was performed, including X-ray diffraction (XRD), rheology, gel fraction and swelling ability, in vitro drug release, and in vitro macrophage prostaglandin E2 (PGE2) production testing. The effects of ibuprofen’s electrostatic interaction with a lipid or polymer on the physicochemical and dissolution characterisation of ibuprofen hydrogels were evaluated. The results showed that the S3 (with lipid conjugation) hydrogel provided higher conjugation efficiency and prolonged drug release compared with the S6 hydrogel.

Reprogramming of arachidonate metabolism confers drug resistance to glioblastoma through Enhancing Mitochondrial Activity in Fatty Acid Oxidation

Background Sp1 is involved in the recurrence of glioblastoma (GBM) due to the acquirement of resistance to temozolomide (TMZ). Particularly, the role of Sp1 in metabolic reprogramming for drug resistance remains unknown. Methods RNA-Seq and mass spectrometry were used to analyze gene expression and metabolites amounts in paired GBM specimens (primary vs. recurrent) and in paired GBM cells (sensitive vs. resistant). ω-3/6 fatty acid and arachidonic acid (AA) metabolism in GBM patients were analyzed by targeted metabolome. Mitochondrial functions were determined by Seahorse XF Mito Stress Test, RNA-Seq, metabolome and substrate utilization for producing ATP. Therapeutic options targeting prostaglandin (PG) E2 in TMZ-resistant GBM were validated in vitro and in vivo. Results Among the metabolic pathways, Sp1 increased the prostaglandin-endoperoxide synthase 2 expression and PGE2 production in TMZ-resistant GBM. Mitochondrial genes and metabolites were obviously increased by PGE2, and these characteristics were required for developing resistance in GBM cells. For inducing TMZ resistance, PGE2 activated mitochondrial functions, including fatty acid β-oxidation (FAO) and tricarboxylic acid (TCA) cycle progression, through PGE2 receptors, E-type prostanoid (EP)1 and EP3. Additionally, EP1 antagonist ONO-8713 inhibited the survival of TMZ-resistant GBM synergistically with TMZ. Conclusion Sp1-regulated PGE2 production activates FAO and TCA cycle in mitochondria, through EP1 and EP3 receptors, resulting in TMZ resistance in GBM. These results will provide us a new strategy to attenuate drug resistance or to re-sensitize recurred GBM.

Synthesis of Halogenated 1,5-Diarylimidazoles and Their Inhibitory Effects on LPS-Induced PGE2 Production in RAW 264.7 Cells

A series of halogenated 1,5-diarylimidazole compounds were synthesized and their inhibitory effects on LPS-induced PGE2 production in RAW 264.7 cells were evaluated. A wide variety of 2,4-, 4-, and 2-halogenated 5-aryl-1-(4-methylsulfonylphenyl)imidazoles were synthesized for SAR study via two different pathways. Overall, 4-halogenated 5-aryl-1-(4-methylsulfonylphenyl)imidazoles, regardless of the species of halogen, exhibited very strong inhibitory activities of PGE2 production. Among them, 4-chloro-5-(4-methoxyphenyl)-1-(4-methylsulfonylphenyl)imidazole (3, IC50 3.3 nM ± 2.93), and 4-chloro-5-(4-chlorophenyl)-1-(4-methylsulfonylphenyl)imidazole (13, IC50 5.3 nM ± 0.23) showed the best results.

Multi-Omics Analysis of Anti-Inflammatory Action of Alkaline Extract of the Leaves of Sasa sp.

Efficient utilization of alkaline extracts of several plants for the treatment of oral diseases has been reported. To investigate the mechanism of anti-inflammatory activity of alkaline extract of the leaves of Sasa sp. (SE), multi-omics analysis using metabolomics and DNA array was performed. Human gingival fibroblasts (HGFs) were treated for IL-1β to induce inflammation (detected by PGE2 production in culture medium) in the presence or absence of SE. Both IL-1β and SE showed slight hormetic growth stimulation against HGF. SE inhibited PGE2 production dose- and time-dependently. Its inhibitory action was more pronounced by first treating the cells with SE, rather than with IL-1β. At 3 h after IL-1β treatment, 18 amino acids (except cysteine and glutamic acid), total glutathione (GSH, GSSG, Cys-GSH disulfide), Met-sulfoxide, 5-oxoproline, and SAM declined, whereas DNA expressions of AKT, CASP3, and CXCL3 were elevated. These changes were reversed by simultaneous treatment with SE. The present study suggests that the anti-inflammatory action of SE is mediated via various metabolic pathways for cell survival, apoptosis, and leukocyte recruitment.

Bone Marrow Mesenchymal Stromal Cells on Silk Fibroin Scaffolds to Attenuate Polymicrobial Sepsis Induced by Cecal Ligation and Puncture

Suitable scaffolds with appropriate mechanical and biological properties can improve mesenchymal stromal cell (MSC) therapy. Because silk fibroins (SFs) are biocompatible materials, they were electrospun and applied as scaffolds for MSC therapy. Consequently, interferon (IFN)-primed human bone marrow MSCs on SF nanofibers were administered into a polymicrobial sepsis murine model. The IL-6 level gradually decreased from 40 ng/mL at 6 h after sepsis to 35 ng/mL at 24 h after sepsis. The IL-6 level was significantly low as 5 ng/mL in primed MSCs on SF nanofibers, and 15 ng/mL in primed MSCs on the control surface. In contrast to the acute response, inflammation-related factors, including HO-1 and COX-2 in chronic liver tissue, were effectively inhibited by MSCs on both SF nanofibers and the control surface at the 5-day mark after sepsis. An in vitro study indicated that the anti-inflammatory function of MSCs on SF nanofibers was mediated through enhanced COX-2-PGE2 production, as indomethacin completely abrogated PGE2 production and decreased the survival rate of septic mice. Thus, SF nanofiber scaffolds potentiated the anti-inflammatory and immunomodulatory functions of MSCs, and were beneficial as a culture platform for the cell therapy of inflammatory disorders.

NSP2 Is Important for Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus to Trigger High Fever-Related COX-2-PGE2 Pathway in Pigs

In 2006, atypical porcine reproductive and respiratory syndrome (PRRS) caused by a highly pathogenic PRRSV (HP-PRRSV) strain broke out in China. Atypical PRRS is characterized by extremely high fever and high mortality in pigs of all ages. Prostaglandin E2 (PGE2) derived from arachidonic acid through the activation of the rate-limiting enzyme cyclooxygenase type 1/2 (COX-1/2) plays an important role in fever. Here, we showed that HP-PRRSV infection increased PGE2 production in microglia via COX-2 up-regulation depending on the activation of MEK1-ERK1/2-C/EBPβ signaling pathways. Then, we screened HP-PRRSV proteins and demonstrated that HP-PRRSV nonstructural protein 2 (NSP2) activated MEK1-ERK1/2-C/EBPβ signaling pathways by interacting with 14-3-3ζ to promote COX-2 expression, leading to PGE2 production. Furthermore, we identified that the amino acid residues 500-596 and 658-777 in HP-PRRSV NSP2 were essential to up-regulate COX-2 expression and PGE2 production. Finally, we made mutant HP-PRRS viruses with the deletion of residues 500-596 and/or 658-777, and found out that these viruses had impaired ability to up-regulate COX-2 and PGE2 production in vitro and in vivo. Importantly, pigs infected with the mutant viruses had relieved fever, clinical symptoms, and mortality. These data might help us understand the molecular mechanisms underlying the high fever and provide clues for the development of HP-PRRSV attenuated vaccines.

Role of the high-affinity reductive iron acquisition pathway of Candida albicans in prostaglandin E2 production, virulence, and interaction with Pseudomonas aeruginosa

Components of the iron reductive pathway of Candida albicans have been implicated in the production of prostaglandin E2 (PGE2) and virulence. However, it is unknown whether other components of this pathway influence PGE2. We investigated the role of the iron reductive pathway of C. albicans in biofilm formation, PGE2 production, and virulence in Caenorhabditis elegans. Additionally, as the co-occurrence of C. albicans and Pseudomonas aeruginosa in host tissues is frequent and involves competition for host-associated iron, we examined the effects of this interaction. Deletion of multicopper oxidase gene, FET99, and iron permease genes, FTH1 and FTH2, affected biofilm metabolic activity, and for the FTH2 mutant, also biofilm morphology. Deletion of CCC1 (vacuolar iron transporter) and CCC2 (P-type ATPase copper importer) also influenced biofilm morphology. For PGE2 production, deletion of FET99, FTH1, FTH2, CCC1, and CCC2 caused a significant reduction by monomicrobial biofilms, while FTH2deletion caused the highest reduction in polymicrobial biofilms. URA3 positive mutants of FET99 and FTH2 demonstrated attenuated virulence in C. elegans, potentially due to the inability of mutants to form hyphae in vivo. Deductively, the role of the iron reductive pathway in PGE2 synthesis is indirect, possibly due to their role in iron homeostasis. Lay Summary Iron uptake is vital for disease-causing microbes like Candida albicans. Using strains deficient in some iron-uptake genes, we show that iron-uptake genes, especially FET99 and FTH2, play a role in biofilm formation, prostaglandin production, and virulence in the nematode infection model.