Activation of liver X receptors inhibit LPS-induced inflammatory response in primary bovine mammary epithelial cells

Neuroprotection of isoorientin against microglia activation induced by lipopolysaccharide via regulating GSK3β, NF-κb and Nrf2/HO-1 pathways

Background: Isoorientin (ISO), a flavone C-glycoside, is a glycogen synthase kinase 3β (GSK3β) substrate-competitive inhibitor. ISO has potential in treatment of Alzheimer's disease (AD). An excessive activation of GSK3β can lead to neuroinflammation causing neuronal damage. Microglia cells, as resident immune cells of the central nervous system, mediate neuroinflammation. Here, we studied the effects of ISO on microglial activation to alleviate neuroinflammation.

Methods: Effects of ISO were observed upon the stimulation of mouse microglia BV2 or SIM-A9 cells by lipopolysaccharide (LPS). Lithium chloride (LiCl) was the positive control as a GSK3β inhibitor. The release of TNF-α and NO were analyzed by ELISA and Griess assays, while expressions of COX-2, Iba-1, BDNF, GSK3β, NF-κB p65, IκB, Nrf2 and HO-1 were detected by Western blotting. In the co-culture model of SIM-A9 cells and differentiated SH-SY5Y human neuroblastoma cells, effects of ISO on microglia-mediated neuronal damage were evaluated with the MTS assay.

Results: ISO significantly inhibited the production of TNF-α (p < 0.01), NO (p < 0.001) and the expression of COX-2 (p < 0.01) and Iba-1 (p < 0.05) induced by LPS, and increased BDNF. The cell viability of SH-SY5Y was inhibited by LPS in the co-culture, which was prevented by ISO pretreatment. ISO increased the expression of p-GSK3β (Ser9), IκB and HO-1 in the cytoplasm, decreased NF-κB p65 and increased Nrf2 in the nucleus compared with the LPS group.

Conclusion: ISO attenuated the activation of microglia through regulating the GSK3β, NF-κB and Nrf2/HO-1 signaling pathways to exert neuroprotection.

GSK3β Substrate-competitive Inhibitors Regulate the gut Homeostasis and Barrier Function to Inhibit Neuroinflammation in Scopolamine-induced Alzheimer's Disease Model Mice

Alzheimer's disease (AD) is a neurodegenerative disease mainly characterized by cognitive impairment. Glycogen synthase kinase 3 (GSK3β) is a potential therapeutic target against AD. Isoorientin (ISO), a GSK3β substrate competitive inhibitor, plays anti-AD effects in in vitro and in vivo AD model. TFGF-18 is an ISO synthetic analog with improved potency, but its neuroprotective effect in vivo remains to be elucidated, and the underlying mechanisms of GSK3β inhibitor against AD need to be clarified. This study investigated the TFGF-18 and ISO effects on gut homeostasis and neuroinflammation in scopolamine (SCOP)-induced AD mice. And the protection on barrier function was observed in in vitro blood-brain barrier (BBB) model of mouse brain microvascular endothelial cells (bEnd.3). The results show that TFGF-18 and ISO improved cognitive function in SCOP-induced mice, and inhibited cholinergic system disorders and inflammation in the brain and intestine, decreased the level of lipopolysaccharides (LPS) in serum and intestine, protected the diversity and balance of intestinal microbiome, increased the expressions of tight junction protein (ZO-1, occludin), brain derived neurotrophic factor (BDNF) and glial cell-derived neurotrophic factor (GDNF) in the mouse brain and intestine. In addition, TFGF-18 and ISO protected against barrier damage in LPS-stimulated BBB model of bEnd.3 cells in vitro. TFGF-18 and ISO increased the ratio of p-GSK3β/GSK3β, suppressed toll-like receptors 4 (TLR-4) expression and nuclear factor kappa-B (NF-κB) activation in vivo and in vitro, and increased the expressions of β-catenin, nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) in vitro. In conclusion, The GSK3β inhibitors TFGF-18 and ISO modulate the gut homeostasis and barrier function to inhibit neuroinflammation and attenuate cognitive impairment by regulating NF-κB, β-catenin and Nrf2/HO-1 pathways.

The involvement of peroxisome proliferator-activated receptor gamma (PPARγ) in anti-inflammatory activity of N-stearoylethanolamine

Background

N-stearoylethanolamine (NSE) is a bioactive lipid amine with a wide range of biological activities. Anti-inflammatory properties of NSE were previously confirmed on multiple animal models. However, the molecular mechanisms of anti-inflammatory action of NSE remain unclear. In the current study, we examined the involvement of nuclear receptor peroxisome proliferator-activated receptor gamma (PPARγ) in the NF-kB –dependent pathway of anti-inflammatory action of NSE using different methodological approaches.

Methods

Molecular modeling calculated the possibility of NSE binding PPAR. Ex vivo experiment, using selective agonist of PPARα/γ - LY-171883 and antagonist of PPARγ - GW9662, examined the role of PPARα/γ in the NSE’s effect on nuclear NF-kB translocation in LPS-activated rat peritoneal macrophages. Finally, the NSE’s action on mRNA level of PPARγ-dependent genes was studied in the liver of insulin-resistant rats.

Results

The results of molecular docking showed that NSE could bind to PPARγ and compete for the binding site with antagonist GW9662 and agonist LY-171883. These data was supported by in vitro study where pre-treatment with NSE prevented further LPS-induced NF-kB translocation into the nuclei of rat peritoneal macrophages. NSE treatment before GW9662 and LPS addition normalized the level of NF-kB translocation and IL-1β content. This finding confirmed a competitive binding of NSE with GW9662 for the ligand-binding domain of PPARγ. Additional in vivo study showed that NSE administration changed the mRNA expression of several PPARγ target genes, including SLC27A1 encoding fatty acid transport protein-1 and IL1RN - interleukin-1 receptor antagonist in insulin resistant rats.

Conclusion

NSE suppressed nuclear translocation of NF-κB in LPS-stimulated peritoneal macrophages via PPARγ and changed hepatic mRNA expression of PPARγ target genes (SLC27A1, IL1RN) in insulin resistant rats.

Pharmacological effects of higenamine based on signalling pathways and mechanism of action

Higenamine (HG) is a chemical compound found in various plants, such as aconite. Recent pharmacological studies have demonstrated its effectiveness in the management of many diseases. Several mechanisms of action of HG have been proposed; however, they have not yet been classified. This review summarises the signalling pathways and pharmacological targets of HG, focusing on its potential as a naturally extracted drug. Articles related to the pharmacological effects, signalling pathways and pharmacological targets of HG were selected by searching the keyword "Higenamine" in the PubMed, Web of Science and Google Scholar databases without limiting the search by publication years. HG possesses anti-oxidant, anti-apoptotic, anti-inflammatory, electrophysiology regulatory, anti-fibrotic and lipid-lowering activities. It is a structural analogue of catecholamines and possesses characteristics similar to those of adrenergic receptor ligands. It can modulate multiple targets, including anti-inflammation- and anti-apoptosis-related targets and some transcription factors, which directly or indirectly influence the disease course. Other naturally occurring compounds, such as cucurbitacin B (Cu B) and 6-gingerol (6-GR), can be combined with HG to enhance its anti-apoptotic activity. Although significant research progress has been made, follow-up pharmacological studies are required to determine the exact mechanism of action, new signalling pathways and targets of HG and the effects of using it in combination with other drugs.

Application of Metabolomics in Diagnosis of Cow Mastitis: A Review

Cow mastitis, with high incidence rate and complex cause of disease, is one of the main diseases that affect the development of dairy industry in the world. Clinical mastitis and subclinical mastitis caused by Staphylococcus aureus, Escherichia coli, Streptococcus, and other pathogens have a huge potential safety hazard to food safety and the rapid development of animal husbandry. The economic loss caused by cow mastitis is billions of dollars every year in the world. In recent years, the omics technology has been widely used in animal husbandry with the continuous breakthrough of sequencing technology and the continuous reduction of sequencing cost. For dairy cow mastitis, the traditional diagnostic technique, such as histopathological screening, somatic cell count, milk pH test, milk conductivity test, enzyme activity test, and infrared thermography, are difficult to fully and comprehensively clarify its pathogenesis due to their own limitations. Metabolomics technology is an important part of system biology, which can simultaneously analyze all low molecular weight metabolites such as amino acids, lipids, carbohydrates under the action of complex factors including internal and external environment and in a specific physiological period accurately and efficiently, and then clarify the related metabolic pathways. Metabolomics, as the most downstream of gene expression, can amplify the small changes of gene and protein expression at the level of metabolites, which can more fully reflect the cell function. The application of metabolomics technology in cow mastitis can analyze the hetero metabolites, identify the related biomarkers, and reveal the physiological and pathological changes of cow mammary gland, so as to provide valuable reference for the prediction, diagnosis, and treatment of mastitis. The research progress of metabolomics technology in cow mastitis in recent years was reviewed, in order to provide guidance for the development of cow health and dairy industry safety in this manuscript.

Effects of sodium salicylate and time postpartum on mammary tissue proliferation, gene transcript profile, and DNA methylation

Previous studies have demonstrated nonsteroidal antiinflammatory drug treatment in early lactation had a positive impact on whole-lactation milk production in older cows. The objective of this study was to evaluate proliferative, transcriptional, and epigenetic changes in the mammary gland that could explain increased production responses due to nonsteroidal antiinflammatory drug treatment. Sodium salicylate (SAL; 125 g/d) or water (CON) were administered via oral drench to multiparous Holstein cows (n = 8/treatment) once daily for 3 d beginning approximately 24 h after parturition, and mammary tissue was collected on d 1, 4, and 45 postpartum. Day 1 tissue was collected immediately preceding the initial drench, and d 4 tissue was collected 24 h following the final drench. Blood was collected twice weekly and analyzed for plasma glucose, insulin, β-hydroxybutyrate, free fatty acids, and prolactin. Cows were milked twice daily until d 7 of lactation, and thrice daily for the remainder of the study. Total RNA extracted from tissue was deep-sequenced and analyzed for differential gene expression using DESeq2. We detected no treatment effect on milk yield or plasma metabolites through 45 d of lactation; additionally, no change in mammary epithelial cell proliferation was detected when assessed by Ki67 labeling. Comparison of SAL versus CON revealed that only 16 of 18,286 genes were differentially expressed (false discovery rate <0.1) in mammary tissue collected on d 45, whereas no differentially expressed genes due to treatment were detected on d 1 or 4. Analysis of transcriptional differences over time showed downregulation of pathways related to immune cell recruitment and differentiation, and extensive overlap with pathways related to cholesterol synthesis and liver X receptor signaling. Global DNA methylation of mammary tissue was decreased for CON compared with SAL. Transcriptome analysis emphasized extensive involvement of immune-related signaling pathways in the switch from lactogenesis to galactopoiesis, and changes in methylation with SAL treatment merit future investigation into epigenetic effects on milk production.

The Physiological Roles of Vitamin E and Hypovitaminosis E in the Transition Period of High-Yielding Dairy Cows

Simple Summary

In high-yield cows, most production diseases occur during transition periods. Alpha-tocopherol, the most biologically active form of vitamin E, declines in blood and reaches the lowest levels (hypovitaminosis E) around calving. Hypovitaminosis E is associated with the incidence of peripartum diseases. Therefore, many studies which have been published for more than 30 years have investigated the effects of α-tocopherol supplementation. This α-tocopherol deficiency was thought to be caused by complex factors. However, until recently, the physiological factors or pathways underlying hypovitaminosis E in the transition period have been poorly understood. In the last 10 years, the α-tocopherol-related genes expression, which regulate the metabolism, transportation, and tissue distribution of α-tocopherol in humans and rodents, has been reported in ruminant tissues. In this paper, we discuss at least six physiological phenomena that occur during the transition period and may be candidate factors predisposing to a decreased blood α-tocopherol level and hypovitaminosis E with changes in α-tocopherol-related genes expression.

Abstract

Levels of alpha-tocopherol (α-Toc) decline gradually in blood throughout prepartum, reaching lowest levels (hypovitaminosis E) around calving. Despite numerous reports about the disease risk in hypovitaminosis E and the effect of α-Toc supplementation on the health of transition dairy cows, its risk and supplemental effects are controversial. Here, we present some novel data about the disease risk of hypovitaminosis E and the effects of α-Toc supplementation in transition dairy cows. These data strongly demonstrate that hypovitaminosis E is a risk factor for the occurrence of peripartum disease. Furthermore, a study on the effectiveness of using serum vitamin levels as biomarkers to predict disease in dairy cows was reported, and a rapid field test for measuring vitamin levels was developed. By contrast, evidence for how hypovitaminosis E occurred during the transition period was scarce until the 2010s. Pioneering studies conducted with humans and rodents have identified and characterised some α-Toc-related proteins, molecular players involved in α-Toc regulation followed by a study in ruminants from the 2010s. Based on recent literature, the six physiological factors: (1) the decline in α-Toc intake from the close-up period; (2) changes in the digestive and absorptive functions of α-Toc; (3) the decline in plasma high-density lipoprotein as an α-Toc carrier; (4) increasing oxidative stress and consumption of α-Toc; (5) decreasing hepatic α-Toc transfer to circulation; and (6) increasing mammary α-Toc transfer from blood to colostrum, may be involved in α-Toc deficiency during the transition period. However, the mechanisms and pathways are poorly understood, and further studies are needed to understand the physiological role of α-Toc-related molecules in cattle. Understanding the molecular mechanisms underlying hypovitaminosis E will contribute to the prevention of peripartum disease and high performance in dairy cows.

Sigma-2 Receptor-A Potential Target for Cancer/Alzheimer's Disease Treatment via Its Regulation of Cholesterol Homeostasis

The sigma receptors were classified into sigma-1 and sigma-2 receptor based on their different pharmacological profiles. In the past two decades, our understanding of the biological and pharmacological properties of the sigma-1 receptor is increasing; however, little is known about the sigma-2 receptor. Recently, the molecular identity of the sigma-2 receptor has been identified as TMEM97. Although more and more evidence has showed that sigma-2 ligands have the ability to treat cancer and Alzheimer’s disease (AD), the mechanisms connecting these two diseases are unknown. Data obtained over the past few years from human and animal models indicate that cholesterol homeostasis is altered in AD and cancer, underscoring the importance of cholesterol homeostasis in AD and cancer. In this review, based on accumulated evidence, we proposed that the beneficial roles of sigma-2 ligands in cancer and AD might be mediated by their regulation of cholesterol homeostasis.

Hepatic Transcriptome Analysis Identifies Divergent Pathogen-Specific Targeting-Strategies to Modulate the Innate Immune System in Response to Intramammary Infection

Mastitis is one of the major risks for public health and animal welfare in the dairy industry. Two of the most important pathogens to cause mastitis in dairy cattle are Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). While S. aureus generally induces a chronic and subclinical mastitis, E. coli is an important etiological pathogen resulting in an acute and clinical mastitis. The liver plays a central role in both, the metabolic and inflammatory physiology of the dairy cow, which is particularly challenged in the early lactation due to high metabolic and immunological demands. In the current study, we challenged the mammary glands of Holstein cows with S. aureus or E. coli, respectively, mimicking an early lactation infection. We compared the animals' liver transcriptomes with those of untreated controls to investigate the hepatic response of the individuals. Both, S. aureus and E. coli elicited systemic effects on the host after intramammary challenge and seemed to use pathogen-specific targeting strategies to bypass the innate immune system. The most striking result of our study is that we demonstrate for the first time that S. aureus intramammary challenge causes an immune response beyond the original local site of the mastitis. We found that in the peripheral liver tissue defined biological pathways are switched on in a coordinated manner to balance the immune response in the entire organism. TGFB1 signaling plays a crucial role in this context. Important pathways involving actin and integrin, key components of the cytoskeleton, were downregulated in the liver of S. aureus infected cows. In the hepatic transcriptome of E. coli infected cows, important components of the complement system were significantly lower expressed compared to the control cows. Notably, while S. aureus inhibits the cell signaling by Rho GTPases in the liver, E. coli switches the complement system off. Also, metabolic hepatic pathways (e.g., lipid metabolism) are affected after mammary gland challenge, demonstrating that the liver restricts metabolic tasks in favor of the predominant immune response after infection. Our results provide new insights for the infection-induced modifications of the dairy cow's hepatic transcriptome following mastitis.

Quercetin Inhibits Inflammatory Response Induced by LPS from Porphyromonas gingivalis in Human Gingival Fibroblasts via Suppressing NF-κB Signaling Pathway

Quercetin, a natural flavonol existing in many food resources, has been reported to be an effective antimicrobial and anti-inflammatory agent for restricting the inflammation in periodontitis. In this study, we aimed to investigate the anti-inflammatory effects of quercetin on Porphyromonas gingivalis (P. gingivalis) lipopolysaccharide- (LPS-) stimulated human gingival fibroblasts (HGFs). HGFs were pretreated with quercetin prior to LPS stimulation. Cell viability was evaluated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. The levels of inflammatory cytokines, including interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), along with chemokine interleukin-8 (IL-8), were determined by enzyme-linked immunosorbent assay (ELISA). The mRNA levels of IL-1β, IL-6, IL-8, TNF-α, IκBα, p65 subunit of nuclear factor-kappa B (NF-κB), peroxisome proliferator-activated receptor-γ (PPAR-γ), liver X receptor α (LXRα), and Toll-like receptor 4 (TLR4) were measured by real-time quantitative PCR (RT-qPCR). The protein levels of IκBα, p-IκBα, p65, p-p65, PPAR-γ, LXRα, and TLR4 were characterized by Western blotting. Our results demonstrated that quercetin inhibited the LPS-induced production of IL-1β, IL-6, IL-8, and TNF-α in a dose-dependent manner. It also suppressed LPS-induced NF-κB activation mediated by TLR4. Moreover, the anti-inflammatory effects of quercetin were reversed by the PPAR-γ antagonist of GW9662. In conclusion, these results suggested that quercetin attenuated the production of IL-1β, IL-6, IL-8, and TNF-α in P. gingivalis LPS-treated HGFs by activating PPAR-γ which subsequently suppressed the activation of NF-κB.

Engeletin inhibits Lipopolysaccharide/d-galactosamine-induced liver injury in mice through activating PPAR-γ

Liver injury is a serious clinical syndrome that characterized by inflammatory response. Engeletin is known to have anti-inflammatory activity. However, the effects of engeletin on liver injury remain unclear. We aimed to assess the protective effect of engeletin on Lipopolysaccharide (LPS)/d-galactosamine (D-gal)-induced liver injury in mice. Engeletin was administered intraperitoneally 1 h before and 12 h after LPS/D-gal treatment. The results showed that engeletin treatment on LPS/D-gal-induced liver injury in mice have a significant protective effect, as confirmed by the attenuation of liver histopathologic changes, MPO activity, and serum AST and ALT levels. At the meanwhile, it also showed that engeletin inhibited the levels of IL-β and TNF-α in serum and liver tissues. Besides, engeletin blocked the activation of NF-κB induced by LPS/D-gal and induced the expression of PPAR-γ in a dose-dependently manner. These findings suggested that engeletin may have a protective effect against liver injury.

Role of Liver X Receptor in Mastitis Therapy and Regulation of Milk Fat Synthesis

Mastitis is important disease that causes huge economic losses in the dairy industry. In recent years, antibiotic therapy has become the primary treatment for mastitis, however, due to drug residue in milk and food safety factors, we lack safe and effective drugs for treating mastitis. Therefore, new targets and drugs are urgently needed to control mastitis. LXRα, one of the main members of the nuclear receptor superfamily, is reported to play important roles in metabolism, infection and immunity. Activation of LXRα could inhibit LPS-induced mastitis. Furthermore, LXRα is reported to enhance milk fat production, thus, LXRα may serve as a new target for mastitis therapy and regulation of milk fat synthesis. This review summarizes the effects of LXRα in regulating milk fat synthesis and treatment of mastitis and highlights the potential agonists involved in both issues.

MicroRNA-155 Promotes Heat Stress-Induced Inflammation via Targeting Liver X Receptor α in Microglia

Background: The neuroinflammatory responses of microglial cells play an important role in the process of brain dysfunction caused by heat stroke. MicroRNAs are reportedly involved in a complex signaling network and have been identified as neuroinflammatory regulators. In this study, we determined the biological roles of microRNA-155 in the inflammatory responses in heat-stressed microglia and explored the underlying mechanisms.

Methods: MicroRNA-155 mimic and inhibitor were used to separately upregulate or downregulate microRNA-155 expression. The activation state of BV-2 microglial cells (BV-2 cells) was assessed via immunoreactions using the microglial marker CD11b and CD68. Levels of induced interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were measured using real-time reverse transcription polymerase chain reaction (RT-PCR) and enzyme linked immunosorbent assays (ELISAs). The activation of nuclear factor kappa B (NF-κB) signaling proteins was evaluated by Western blotting for inhibitory kappa B alpha (IκBα) and NF-κB p65 phosphorylation and indirect immunofluorescence analysis using a p65 phosphorylation antibody. A luciferase reporter assay was used to verify liver X receptor α (LXRα) as a target gene of microRNA-155.

Results: Heat stress significantly induced IL-1β, IL-6, and TNF-α release and increased the expression of CD11b and CD68. In addition, IκBα and NF-κB p65 phosphorylation were dramatically increased by heat stress, and microRNA-155 expression was also elevated. High expression of microRNA-155 in heat-stressed microglial cells was inversely correlated with LXRα expression. We then determined the role of microRNA-155 in the heat stress-induced inflammatory responses. The results revealed that by targeting LXRα, microRNA-155 enhanced NF-κB signaling activation and facilitated immune inflammation in heat stress-treated BV-2 cells.

Conclusion: MicroRNA-155 promotes heat stress-induced inflammatory responses in microglia. The underlying mechanisms may include facilitating inflammatory factors expression by increasing NF-κB pathway activation via targeting LXRα.

Saikosaponin A Inhibits LPS-Induced Endometritis in Mice Through Activating Nrf2 Signaling Pathway

Saikosaponin A (SSA) is the major triterpenoid glycoside isolated from Bupleurum falcatum. In this study, we reported the protective effects and mechanism of SSA on lipopolysaccharide (LPS)-induced endometritis in mice. The pathological changes and myeloperoxidase (MPO) activity of uterus tissues were evaluated by hematoxylin and eosin (H&E) staining and MPO detection kit. Inflammatory cytokines TNF-α, IL-1ß, and IL-6 production were detected by ELISA. The expression of protein was measured by western blot analysis. The results showed that SSA administration inhibited inflammatory cell infiltration as confirmed by the decreased MPO activity. LPS-induced uterus histological changes were also suppressed by SSA. Meanwhile, LPS-induced TNF-α, IL-1ß, and IL-6 production were reduced by SSA administration. The phosphorylation levels of nuclear factor kappa B (NF-κB) and inhibitor of kappa B (IκBα) induced by LPS were inhibited by SSA. In addition, the expression of nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase (HO-1) were upregulated by SSA in a concentration-dependent manner. These results provide evidence that SSA protects against LPS-induced endometritis through inhibiting inflammatory response. SSA may be used as a potential therapeutic agent for the treatment of endometritis.

Abietic acid attenuates IL-1β-induced inflammation in human osteoarthritis chondrocytes

Abietic acid has been reported to have anti-inflammatory activity. However, whether abietic acid has anti-inflammatory effects against osteoarthritis (OA) remains unclear. The present study aimed to measure the anti-inflammatory effects of abietic acid on OA in vitro. Human osteoarthritis chondrocytes were pretreated with abietic acid 1 h before IL-1β treatment. The results showed that treatment of abietic acid significantly inhibited IL-1β-induced TNF-α, NO, PGE2 production, and COX-2 expression. Abietic acid also concentration-dependently suppressed MMP1, MMP3, and MMP13 production induced by IL-1β. Moreover, the increased phosphorylation levels of NF-κB p65 and IκBα were inhibited by the treatment of abietic acid. We also found that the expression of PPAR-γ was increased by abietic acid. The inhibition of abietic acid on TNF-α, NO, and PGE2 production were reversed by GW9662, the inhibitor of PPAR-γ. In conclusion, the study elucidated abietic acid suppressed IL-1β-induced inflammation in human osteoarthritis chondrocytes by activating PPAR-γ.

Nuciferine inhibits LPS-induced inflammatory response in BV2 cells by activating PPAR-γ

Nuciferine, a bioactive component extracted from the lotus leaf, has been reported to have various anti-inflammatory effects. In the present study, we aimed to investigate the anti-inflammatory effects and mechanism of nuciferine on lipopolysaccharide (LPS)-stimulated BV2 microglia cells. The anti-inflammatory activity of nuciferine was measured by ELISA to detect the inflammatory mrdiators secretion in LPS-simulated BV2 microglia cells. The results demonstrated that nuciferine significantly inhibited LPS-induced TNF-α, IL-1β, PGE₂ and NO secretion. LPS-induced NF-κB activation was also suppressed by nuciferine. Further studies showed that nuciferine increased the expression of PPAR-γ. Functional aspects were analyzed using PPAR-γ specific inhibitor GW9662, which attenuated the LPS-induced secretion of proinflammatory mediators, such as TNF-α, IL-1β, PGE₂, and NO. In conclusion, these results suggested that nuciferine activated PPAR-γ, which subsequently inhibited LPS-induced inflammation in BV2 cells.