Displaying publications 1 - 20 of 71 in total

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  1. Chee Wezen X, Chandran A, Eapen RS, Waters E, Bricio-Moreno L, Tosi T, et al.
    J Chem Inf Model, 2022 May 23;62(10):2586-2599.
    PMID: 35533315 DOI: 10.1021/acs.jcim.2c00300
    Lipoteichoic acid synthase (LtaS) is a key enzyme for the cell wall biosynthesis of Gram-positive bacteria. Gram-positive bacteria that lack lipoteichoic acid (LTA) exhibit impaired cell division and growth defects. Thus, LtaS appears to be an attractive antimicrobial target. The pharmacology around LtaS remains largely unexplored with only two small-molecule LtaS inhibitors reported, namely "compound 1771" and the Congo red dye. Structure-based drug discovery efforts against LtaS remain unattempted due to the lack of an inhibitor-bound structure of LtaS. To address this, we combined the use of a molecular docking technique with molecular dynamics (MD) simulations to model a plausible binding mode of compound 1771 to the extracellular catalytic domain of LtaS (eLtaS). The model was validated using alanine mutagenesis studies combined with isothermal titration calorimetry. Additionally, lead optimization driven by our computational model resulted in an improved version of compound 1771, namely, compound 4 which showed greater affinity for binding to eLtaS than compound 1771 in biophysical assays. Compound 4 reduced LTA production in S. aureus dose-dependently, induced aberrant morphology as seen for LTA-deficient bacteria, and significantly reduced bacteria titers in the lung of mice infected with S. aureus. Analysis of our MD simulation trajectories revealed the possible formation of a transient cryptic pocket in eLtaS. Virtual screening (VS) against the cryptic pocket led to the identification of a new class of inhibitors that could potentiate β-lactams against methicillin-resistant S. aureus. Our overall workflow and data should encourage further drug design campaign against LtaS. Finally, our work reinforces the importance of considering protein conformational flexibility to a successful VS endeavor.
    Matched MeSH terms: Lipopolysaccharides/pharmacology
  2. Sarmiento ME, Chin KL, Lau NS, Aziah I, Ismail N, Norazmi MN, et al.
    Fish Shellfish Immunol, 2021 Oct;117:148-156.
    PMID: 34358702 DOI: 10.1016/j.fsi.2021.08.001
    Horseshoe crabs (HSCs) are living fossil species of marine arthropods with a long evolutionary history spanning approximately 500 million years. Their survival is helped by their innate immune system that comprises cellular and humoral immune components to protect them against invading pathogens. To help understand the genetic mechanisms involved, the present study utilised the Illumina HiSeq platform to perform transcriptomic analysis of hemocytes from the HSC, Tachypleus gigas, that were challenged with lipopolysaccharides (LPS). The high-throughput sequencing resulted in 352,077,208 and 386,749,136 raw reads corresponding to 282,490,910 and 305,709,830 high-quality mappable reads for the control and LPS-treated hemocyte samples, respectively. Based on the log-fold change of > 0.3 or 
    Matched MeSH terms: Lipopolysaccharides/pharmacology*
  3. Hambali A, Jusril NA, Md Hashim NF, Abd Manan N, Adam SK, Mehat MZ, et al.
    J Alzheimers Dis, 2024;99(s1):S119-S138.
    PMID: 38250772 DOI: 10.3233/JAD-230875
    BACKGROUND: Neuroinflammation and oxidative stress can aggravate the progression of Alzheimer's disease (AD). Centella asiatica has been traditionally consumed for memory and cognition. The triterpenes (asiaticoside, madecassoside, asiatic acid, madecassic acid) have been standardized in the ethanolic extract of Centella asiatica (SECA). The bioactivity of the triterpenes in different solvent polarities of SECA is still unknown.

    OBJECTIVE: In this study, the antioxidative and anti-neuroinflammatory effects of SECA and its fractions were explored on lipopolysaccharides (LPS)-induced microglial cells.

    METHODS: HPLC measured the four triterpenes in SECA and its fractions. SECA and its fractions were tested for cytotoxicity on microglial cells using MTT assay. NO, pro-inflammatory cytokines (TNF-α, IL-6, IL-1β), ROS, and MDA (lipid peroxidation) produced by LPS-induced microglial cells were measured by colorimetric assays and ELISA. Nrf2 and HO-1 protein expressions were measured using western blotting.

    RESULTS: The SECA and its fractions were non-toxic to BV2 microglial cells at tested concentrations. The levels of NO, TNF-α, IL-6, ROS, and lipid peroxidation in LPS-induced BV2 microglial cells were significantly reduced (p 

    Matched MeSH terms: Lipopolysaccharides/pharmacology
  4. Bian Z, Liu X, Hu S, Li H, Wood JS, Williamson RT, et al.
    J Nat Prod, 2024 Oct 25;87(10):2459-2467.
    PMID: 39315450 DOI: 10.1021/acs.jnatprod.4c00759
    We report here the orchestration of molecular ion networking (MoIN) and a set of computationally assisted structural elucidation approaches in the discovery and assignment of a new class of rearranged 4,5-seco-abietane diterpenoids including serra A (1), which possesses an unusual 6/6/5/5 fused-ring skeleton system, together with two previously unreported diterpenoids serras B-C (2-3) and five known compounds were isolated from Isodon serra (I. serra). The structures were elucidated by spectroscopic analysis in conjunction with computationally assisted structure elucidation tools. In silico, serras A-C (1-3) bind well to PXR, suggesting their potential role in reducing inflammation. The results of serra A (1) with hPXR demonstrated agonist activity with an EC50 value of 15 μM. Serra A (1), graciliflorin F (4), gerardianin C (5), 11,12,15-trihydroxy-8,11,13-abietatrien-7-one (6), rabdosin D (7), and 15-hydroxysalprionin (8) exhibited promising anti-inflammatory activities in lipopolysaccharide (LPS)-induced RAW 267.4 cells, and their inhibition rates on NO production were more than 65% at 10 μM.
    Matched MeSH terms: Lipopolysaccharides/pharmacology
  5. Azhar NA, Paul BT, Jesse FFA, Chung ELT, Kamarulrizal MI, Mohd Lila MA
    Trop Anim Health Prod, 2022 Aug 12;54(5):265.
    PMID: 35962250 DOI: 10.1007/s11250-022-03262-z
    Pneumonic mannheimiosis is a widespread respiratory bacterial disease of small ruminants caused by Mannheimia haemolytica serotype A2. The disease is known to affect the respiratory organs of infected animals, but its effect on other vital and reproductive organs has not been fully explored. Previous studies have demonstrated increased serum pro-inflammatory cytokine concentration post-challenge with M. haemolytica A2 and its LPS, indicating systemic inflammation in the host. This study determined the potential tissue changes and alterations of sperm parameters due to infection of M. haemolytica A2 and its LPS endotoxin. In this study, twelve experimental bucks were randomly assigned to three groups of four bucks each: group 1 (control group) were intranasally inoculated with 2 mL of PBS pH 7.0, group 2 received 2 mL of 1.2 × 109 CFU/mL M. haemolytica A2 intranasally, and group 3 received 2 mL of LPS extracted from 1.2 × 109 CFU/mL of M. haemolytica A2 intravenously. Semen samples were collected at pre-determined intervals using an electro-ejaculator and analysed immediately after collection. All experimental bucks were slaughtered via exsanguination on day 60 to collect their vital and reproductive organs at necropsy, and the samples were processed and analysed for histopathological changes. The current study has revealed that bucks challenged with M. haemolytica A2 and its LPS exhibited alterations in semen parameters such as motility, wave pattern, viability, and morphological abnormalities. Mild to moderate histopathological changes of the lung, liver, testis, epididymis, vas deferens, prostate, and lymph nodes were also observed in both challenged groups. Therefore, this study revealed the potential harmful effects of respiratory mannheimiosis on the reproductive organs of the infected bucks and sheds light on the expanse of systemic effects of this disease.
    Matched MeSH terms: Lipopolysaccharides/pharmacology
  6. Bindal P, Bindal U, Lin CW, Kasim NHA, Ramasamy TSAP, Dabbagh A, et al.
    Technol Health Care, 2017 Dec 04;25(6):1041-1051.
    PMID: 28800347 DOI: 10.3233/THC-170922
    Dental stem cells isolated for human dental pulp are an excellent source for regenerative medicine and dentistry. Simulation of clinical scenario is one of the crucial challenges for evaluation of the efficacy of DPSCs in various regenerative therapies. In this study we evaluated the viability of DPSCs after treatment with artificial bacterial lipopolysaccharides (LPS) as the main component responsible for inducing inflammatory response in majority of the inflammatory conditions in clinical scenario. Although a number of studies have previously treated stem cells with LPS from bacteria, however the accuracy level of the outcome was not established. Here we have analyzed the outcome using adaptive neuro-fuzzy inferences system (ANFIS) to predict the viability of human DPSCs after treatment with bacterial LPS.
    Matched MeSH terms: Lipopolysaccharides/pharmacology*
  7. Sangaran PG, Ibrahim ZA, Chik Z, Mohamed Z, Ahmadiani A
    Mol Neurobiol, 2021 May;58(5):2407-2422.
    PMID: 33421016 DOI: 10.1007/s12035-020-02227-3
    Neuroinflammation, an inflammatory response within the nervous system, has been shown to be implicated in the progression of various neurodegenerative diseases. Recent in vivo studies showed that lipopolysaccharide (LPS) preconditioning provides neuroprotection by activating Toll-like receptor 4 (TLR4), one of the members for pattern recognition receptor (PRR) family that play critical role in host response to tissue injury, infection, and inflammation. Pre-exposure to low dose of LPS could confer a protective state against cellular apoptosis following subsequent stimulation with LPS at higher concentration, suggesting a role for TLR4 pre-activation in the signaling pathway of LPS-induced neuroprotection. However, the precise molecular mechanism associated with this protective effect is not well understood. In this article, we provide an overall review of the current state of our knowledge about LPS preconditioning in attenuating apoptosis mechanism and conferring neuroprotection via TLR4 signaling pathway.
    Matched MeSH terms: Lipopolysaccharides/pharmacology*
  8. Dewi IP, Dachriyanus, Aldi Y, Ismail NH, Hefni D, Susanti M, et al.
    J Ethnopharmacol, 2024 Feb 10;320:117381.
    PMID: 37967776 DOI: 10.1016/j.jep.2023.117381
    ETHNOPHARMACOLOGICAL RELEVANCE: Garcinia cowa Roxb. is called asam kandis in West Sumatra. This plant contains several quinone compounds, including tetraprenyltoluquinone (TPTQ). The bioactivity of this compound has been tested as an anticancer agent. However, reports regarding its anti-inflammatory effects are still limited, especially against coronavirus disease (Covid-19).

    AIM OF THE STUDY: This study explores the anti-inflammatory effect of TPTQ in silico, in vitro, and in vivo.

    MATERIALS AND METHODS: In silico testing used the Gnina application, opened via Google Colab. The TPTQ structure was docked with the nuclear factor kappa B (NF-ĸB) protein (PDB: 2RAM). In vitro testing began with testing the cytotoxicity of TPTQ against Raw 264.7 cells, using the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) method. A phagocytic activity test was carried out using the neutral red uptake method, and interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) secretion tests were carried out using the enzyme-linked immunosorbent assay (ELISA) method. In vivo, tests were carried out on mice by determining cluster of differentiation 8+ (CD8+), natural killer cell (NK cell), and IL-6 parameters, using the ELISA method.

    RESULTS: TPTQ has a lower binding energy than the native ligand and occupies the same active site as the native ligand. TPTQ decreased the phagocytosis index and secretion of IL-6 and TNF-α experimentally in vitro. TPTQ showed significant downregulation of CD8+ and slightly decreased NK cells and IL-6 secretion in vivo.

    CONCLUSION: The potent inhibitory effect of TPTQ on the immune response suggests that TPTQ can be developed as an anti-inflammatory agent, especially in the treatment of Covid-19.

    Matched MeSH terms: Lipopolysaccharides/pharmacology
  9. Hasan MM, Madhavan P, Ahmad Noruddin NA, Lau WK, Ahmed QU, Arya A, et al.
    Pharm Biol, 2023 Dec;61(1):1135-1151.
    PMID: 37497554 DOI: 10.1080/13880209.2023.2230251
    CONTEXT: Arjunolic acid (AA) is a triterpenoid saponin found in Terminalia arjuna (Roxb.) Wight & Arn. (Combretaceae). It exerts cardiovascular protective effects as a phytomedicine. However, it is unclear how AA exerts the effects at the molecular level.

    OBJECTIVE: This study investigates the cardioprotective effects of arjunolic acid (AA) via MyD88-dependant TLR4 downstream signaling marker expression.

    MATERIALS AND METHODS: The MTT viability assay was used to assess the cytotoxicity of AA. LPS induced in vitro cardiovascular disease model was developed in H9C2 and C2C12 myotubes. The treatment groups were designed such as control (untreated), LPS control, positive control (LPS + pyrrolidine dithiocarbamate (PDTC)-25 µM), and treatment groups were co-treated with LPS and three concentrations of AA (50, 75, and 100 µM) for 24 h. The changes in the expression of TLR4 downstream signaling markers were evaluated through High Content Screening (HCS) and Western Blot (WB) analysis.

    RESULTS: After 24 h of co-treatment, the expression of TLR4, MyD88, MAPK, JNK, and NF-κB markers were upregulated significantly (2-6 times) in the LPS-treated groups compared to the untreated control in both HCS and WB experiments. Evidently, the HCS analysis revealed that MyD88, NF-κB, p38, and JNK were significantly downregulated in the H9C2 myotube in the AA treated groups. In HCS, the expression of NF-κB was downregulated in C2C12. Additionally, TLR4 expression was downregulated in both H9C2 and C2C12 myotubes in the WB experiment.

    DISCUSSION AND CONCLUSIONS: TLR4 marker expression in H9C2 and C2C12 myotubes was subsequently decreased by AA treatment, suggesting possible cardioprotective effects of AA.

    Matched MeSH terms: Lipopolysaccharides/pharmacology
  10. Jalil J, Sabandar CW, Ahmat N, Jamal JA, Jantan I, Aladdin NA, et al.
    Molecules, 2015 Feb 16;20(2):3206-20.
    PMID: 25690285 DOI: 10.3390/molecules20023206
    The crude methanol extracts and fractions of the root and stem barks of Dillenia serrata Thunb. showed 64% to 73% inhibition on the production of prostaglandin E2 (PGE2) in lipopolysaccharide-induced human whole blood using a radioimmunoassay technique. Three triterpenoids isolated from the root bark of the plant, koetjapic (1), 3-oxoolean-12-en-30-oic (2), and betulinic (3) acids, exhibited significant concentration-dependent inhibitory effects on PGE2 production with IC50 values of 1.05, 1.54, and 2.59 μM, respectively, as compared with the positive control, indomethacin (IC50 = 0.45 μM). Quantification of compounds 1 and 3 in the methanol extracts and fractions were carried out by using a validated reversed-phase high performance liquid chromatography (RP-HPLC) method. The ethyl acetate fraction of the stem bark showed the highest content of both compound 1 (15.1%) and compound 3 (52.8%). The strong inhibition of the extracts and fractions on cyclooxygenase-2 (COX-2) enzymatic activity was due to the presence of their major constituents, especially koetjapic and betulinic acids.
    Matched MeSH terms: Lipopolysaccharides/pharmacology
  11. Pang KL, Chin KY, Nirwana SI
    PMID: 36597600 DOI: 10.2174/1871530323666230103153134
    BACKGROUND: The immunomodulatory effects of plants have been utilised to enhance the immunity of humans against infections. However, evidence of such effects of agarwood leaves is very limited despite the long tradition of consuming the leaves as tea.

    OBJECTIVE: This study aimed to investigate the immuno-modulatory effects of agarwood leaf extract (ALE) derived from Aquilaria malaccensis using RAW264.7 murine macrophages.

    METHODS: In this study, RAW264.7 macrophages were incubated with ALE alone for 26 hours or ALE for 2 hours, followed by bacterial lipopolysaccharide for 24 hours. The nitrite and cytokine production (tumour necrosis factor-alpha (TNFα), interleukin (IL)-1β, IL-6, and IL-10), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX2) expression in the macrophages were assayed.

    RESULTS: The study showed that ALE alone was immunostimulatory on the macrophages by increasing the nitrite, TNFα, and IL-6 production and COX2 expression (p<0.05 vs. untreated unstimulated cells). Pre-treatment of ALE suppressed nitrite level and iNOS expression but enhanced TNFα and IL-6 production and COX2 expression (p<0.05 vs. untreated lipopolysaccharides (LPS)-stimulated cells). ALE also increased IL-10 production regardless of LPS stimulation (p<0.05 vs. untreated cells).

    CONCLUSION: ALE was able to promote the immune response of macrophages by upregulating pro-inflammatory cytokine levels and COX2 expression. It also regulated the extent of the inflammation by reducing iNOS expression and increasing IL-10 levels. Thus, ALE may have a role in enhancing the innate immune system against infection; however, its validation from in vivo studies is still pending.

    Matched MeSH terms: Lipopolysaccharides/pharmacology
  12. Abdo Qaid EY, Abdullah Z, Zakaria R, Long I
    Int J Mol Sci, 2022 Nov 03;23(21).
    PMID: 36362262 DOI: 10.3390/ijms232113474
    Neuroinflammation following lipopolysaccharide (LPS) administration induces locomotor deficits and anxiety-like behaviour. In this study, minocycline was compared to memantine, an NMDA receptor antagonist, for its effects on LPS-induced locomotor deficits and anxiety-like behaviour in rats. Adult male Sprague Dawley rats were administered either two different doses of minocycline (25 or 50 mg/kg/day, i.p.) or 10 mg/kg/day of memantine (i.p.) for 14 days four days prior to an LPS (5 mg/kg, i.p.) injection. Locomotor activity and anxiety-like behaviour were assessed using the open-field test (OFT). The phosphorylated tau protein level was measured using ELISA, while the expression and density of brain-derived neurotrophic factor (BDNF) and cAMP response element-binding (CREB) protein in the medial prefrontal cortex (mPFC) were measured using immunohistochemistry and Western blot, respectively. Minocycline treatment reduced locomotor deficits and anxiety-like behaviour associated with reduced phosphorylated tau protein levels, but it upregulated BDNF/CREB protein expressions in the mPFC in a comparable manner to memantine, with a higher dose of minocycline having better benefits. Minocycline treatment attenuated LPS-induced locomotor deficits and anxiety-like behaviour in rats and decreased phosphorylated tau protein levels, but it increased the expressions of the BDNF/CREB proteins in the mPFC.
    Matched MeSH terms: Lipopolysaccharides/pharmacology
  13. Lian J, Zhu X, Du J, Huang B, Zhao F, Ma C, et al.
    Mol Ther, 2023 May 03;31(5):1365-1382.
    PMID: 36733250 DOI: 10.1016/j.ymthe.2023.01.025
    Mesenchymal stem cells regulate remote intercellular signaling communication via their secreted extracellular vesicles. Here, we report that menstrual blood-derived stem cells alleviate acute lung inflammation and injury via their extracellular vesicle-transmitted miR-671-5p. Disruption of this abundantly expressed miR-671-5p dramatically reduced the ameliorative effect of extracellular vesicles released by menstrual blood-derived stem cells on lipopolysaccharide (LPS)-induced pulmonary inflammatory injury. Mechanistically, miR-671-5p directly targets the kinase AAK1 for post-transcriptional degradation. AAK1 is found to positively regulate the activation of nuclear factor κB (NF-κB) signaling by controlling the stability of the inhibitory protein IκBα. This study identifies a potential molecular basis of how extracellular vesicles derived from mesenchymal stem cells improve pulmonary inflammatory injury and highlights the functional importance of the miR-671-5p/AAK1 axis in the progression of pulmonary inflammatory diseases. More importantly, this study provides a promising cell-based approach for the treatment of pulmonary inflammatory disorders through an extracellular vesicle-dependent pathway.
    Matched MeSH terms: Lipopolysaccharides/pharmacology
  14. Susanto H, Sudiana K, Nandika D, Karlinasari L, Arinana A, Karim SA, et al.
    Open Vet J, 2024 Sep;14(9):2269-2279.
    PMID: 39553755 DOI: 10.5455/OVJ.2024.v14.i9.15
    BACKGROUND: The fungus comb is a unique structure inside termites' nests that facilitates the growth of Termitomyces sp. as a nutrient source for the termites. It is known to possess immunomodulatory properties that boost the immune system.

    AIM: The objective of this study was to assess the impact of ethyl acetate extract of fungus comb (EAEFC) on the inflammatory reaction in the spleen of mice induced by intraperitoneal injection of lipopolysaccharide (LPS).

    METHODS: An experimental study was conducted using a post-test-only control group design with male BALB/C mice (n = 24). The mice were divided randomly into four groups, each comprising six mice, and administered substances via gavage. Groups I and III were administered a solution of 5% dimethyl sulfoxide (DMSO) in distilled water, while Groups II and IV were given 500 mg/kg BW EAEFC dissolved in 5% DMSO. On the fifteenth day, Groups I and II received intraperitoneal injections of 5 ml/kg BW saline, while Groups III and IV were injected with 10 mg/kg BW LPS dissolved in saline. After three hours, the mice were euthanized and splenic immunohistology was examined under a light microscope. The results were expressed as mean ± standard deviation, while the group differences were assessed statistically.

    RESULTS: The expression of interleukin (IL)-1, furin, and activated NK cell was significantly higher in the inflamed model after EAEFC supplementation, while the extract suppressed IL-10.

    CONCLUSION: EAEFC was found to alter cytokine expression in the spleen in response to inflammation.

    Matched MeSH terms: Lipopolysaccharides/pharmacology
  15. Yap SK, Zakaria Z, Othman SS, Omar AR
    J Vet Sci, 2018 Mar 31;19(2):207-215.
    PMID: 28693312 DOI: 10.4142/jvs.2018.19.2.207
    Pasteurella multocida serotype B:2 causes hemorrhagic septicemia in cattle and buffalo. The invasion mechanism of the bacterium when invading the bloodstream is unclear. This study aimed to characterize the effects of immunomodulatory molecules, namely dexamethasone and lipopolysaccharide, on the invasion efficiency of P. multocida serotype B:2 toward bovine aortic endothelial cells (BAECs) and the involvement of actin microfilaments in the invasion mechanism. The results imply that treatment of BAECs with lipopolysaccharide at 100 ng/mL for 24 h significantly increases the intracellular bacteria number per cell (p < 0.01) compared with those in untreated and dexamethasone-treated cells. The lipopolysaccharide-treated cells showed a significant decrease in F-actin expression and an increase in G-actin expression (p < 0.001), indicating actin depolymerization of BAECs. However, no significant differences were detected in the invasion efficiency and actin filament reorganization between the dexamethasone-treated and untreated cells. Transmission electron microscopy showed that P. multocida B:2 resided in a vacuolar compartment of dexamethasone-treated and untreated cells, whereas the bacteria resided in cellular membrane of lipopolysaccharide-treated cells. The results suggest that lipopolysaccharide destabilizes the actin filaments of BAECs, which could facilitate the invasion of P. multocida B:2 into BAECs.
    Matched MeSH terms: Lipopolysaccharides/pharmacology*
  16. Karunakaran T, Ee GCL, Ismail IS, Mohd Nor SM, Zamakshshari NH
    Nat Prod Res, 2018 Jun;32(12):1390-1394.
    PMID: 28715912 DOI: 10.1080/14786419.2017.1350666
    Pure β-mangostin (1) was isolated from the stem bark of Garcinia mangostana L. One monoacetate (2) and five O-alkylated β-mangostin derivatives (3-7) were synthesised from β-mangostin. The structures of these compounds were elucidated and determined using spectroscopic techniques such as 1D NMR and MS. The cytotoxicities and anti-inflammatory activities of these five compounds against RAW cell 264.7 were tested. The structural-activity relationship studies indicated that β-mangostin showed a significant activity against the LPS-induced RAW cell 264.7, while the acetyl- as well as the O-alkyl- β-mangostin derivatives did not give good activity. Naturally occurring β-mangostin demonstrated comparatively better anti-inflammatory activity than its synthetic counterparts.
    Matched MeSH terms: Lipopolysaccharides/pharmacology
  17. Haque MA, Jantan I, Harikrishnan H, Abdul Wahab SM
    Planta Med, 2018 Nov;84(17):1255-1264.
    PMID: 29906814 DOI: 10.1055/a-0637-9936
    Magnoflorine, a major bioactive metabolite isolated from Tinospora crispa, has been reported for its diverse biochemical and pharmacological properties. However, there is little report on its underlying mechanisms of action on immune responses, particularly on macrophage activation. In this study, we aimed to investigate the effects of magnoflorine, isolated from T. crispa on the pro-inflammatory mediators generation induced by LPS and the concomitant NF-κB, MAPKs, and PI3K-Akt signaling pathways in U937 macrophages. Differentiated U937 macrophages were treated with magnoflorine and the release of pro-inflammatory mediators was evaluated through ELISA, while the relative mRNA expression of the respective mediators was quantified through qRT-PCR. Correspondingly, western blotting was executed to observe the modulatory effects of magnoflorine on the expression of various markers related to NF-κB, MAPK and PI3K-Akt signaling activation in LPS-primed U937 macrophages. Magnoflorine significantly enhanced the upregulation of TNF-α, IL-1β, and PGE2 production as well as COX-2 protein expression. Successively, magnoflorine prompted the mRNA transcription level of these pro-inflammatory mediators. Magnoflorine enhanced the NF-κB activation by prompting p65, IκBα, and IKKα/β phosphorylation as well as IκBα degradation. Besides, magnoflorine treatments concentration-dependently augmented the phosphorylation of JNK, ERK, and p38 MAPKs as well as Akt. The immunoaugmenting effects were further confirmed by investigating the effects of magnoflorine on specific inhibitors, where the treatment with specific inhibitors of NF-κB, MAPKs, and PI3K-Akt proficiently blocked the magnoflorine-triggered TNF-α release and COX-2 expression. Magnoflorine furthermore enhanced the MyD88 and TLR4 upregulation. The results suggest that magnoflorine has high potential on augmenting immune responses.
    Matched MeSH terms: Lipopolysaccharides/pharmacology*
  18. Moriya S, Tan VP, Yee AK, Parhar IS
    Neurosci Lett, 2019 08 24;708:134330.
    PMID: 31201839 DOI: 10.1016/j.neulet.2019.134330
    In Parkinson's disease (PD), several genes have been identified as the PD-related genes, however, the regulatory mechanisms of these gene expressions have not been fully identified. In this study, we investigated the effect of inflammation, one of the major risk factors in PD on expressions of the PD-related genes. Lipopolysaccharide (LPS) was intraperitoneally administered to mature male zebrafish and gene expressions in the brains were examined by real-time PCR. In the inflammation-related genes, expressions of tnfb, il1b and il6 were increased at 2 days post administration in the 10 μg group, and tnfb expression was also increased at 4 days post administration in the 1 μg and 10 μg group. In the PD-related genes, pink1 expression was significantly decreased at 4 days, atp13a2 expression was significantly increased at 7 days, and uchl1 expression was significantly decreased at 7 days. This suggests that pink1, atp13a2 and uchl1 expressions are regulated by inflammation, and this regulatory mechanism might be involved in the progress of PD.
    Matched MeSH terms: Lipopolysaccharides/pharmacology*
  19. Vallance TM, Ravishankar D, Albadawi DAI, Layfield H, Sheard J, Vaiyapuri R, et al.
    Sci Rep, 2019 12 03;9(1):18258.
    PMID: 31796818 DOI: 10.1038/s41598-019-54617-w
    Platelets are small circulating blood cells that play essential roles in the maintenance of haemostasis via blood clotting. However, they also play critical roles in the regulation of innate immune responses. Inflammatory receptors, specifically Toll-like receptor (TLR)-4, have been reported to modify platelet reactivity. A plethora of studies have reported controversial functions of TLR4 in the modulation of platelet function using various chemotypes and preparations of its ligand, lipopolysaccharide (LPS). The method of preparation of LPS may explain these discrepancies however this is not fully understood. Hence, to determine the impact of LPS on platelet activation, we used ultrapure preparations of LPS from Escherichia coli (LPSEC), Salmonella minnesota (LPSSM), and Rhodobacter sphaeroides (LPSRS) and examined their actions under diverse experimental conditions in human platelets. LPSEC did not affect platelet activation markers such as inside-out signalling to integrin αIIbβ3 or P-selectin exposure upon agonist-induced activation in platelet-rich plasma or whole blood whereas LPSSM and LPSRS inhibited platelet activation under specific conditions at supraphysiological concentrations. Overall, our data demonstrate that platelet activation is not largely influenced by any of the ultrapure LPS chemotypes used in this study on their own except under certain conditions.
    Matched MeSH terms: Lipopolysaccharides/pharmacology*
  20. Lee CY, Li S, Li XF, Stalker DAE, Cooke C, Shao B, et al.
    Reprod Fertil Dev, 2019 May;31(6):1134-1143.
    PMID: 30922440 DOI: 10.1071/RD18277
    RFamide-related peptide (RFRP)-3 reduces luteinising hormone (LH) secretion in rodents. Stress has been shown to upregulate the expression of the RFRP gene (Rfrp) with a concomitant reduction in LH secretion, but an effect on expression of the gonadotrophin-releasing hormone (GnRH) gene (Gnrh1) has not been shown. We hypothesised that lipopolysaccharide (LPS)-induced stress affects expression of Rfrp, the gene for kisspeptin (Kiss1) and/or Gnrh1, leading to suppression of LH levels in rats. Intracerebroventricular injections of RFRP-3 (0.1, 1, 5 nmol) or i.v. LPS (15μgkg-1) reduced LH levels. Doses of 1 and 5 nmol RFRP-3 were then administered to analyse gene expression by in situ hybridisation. RFRP-3 (5 nmol) had no effect on Gnrh1 or Kiss1 expression. LPS stress reduced GnRH and Kiss1 expression, without affecting Rfrp1 expression. These data indicate that LPS stress directly or indirectly reduces Gnrh1 expression, but this is unlikely to be due to a change in Rfrp1 expression.
    Matched MeSH terms: Lipopolysaccharides/pharmacology*
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