Protective effects of strawberry and mulberry fruit polysaccharides on inflammation and apoptosis in murine primary splenocytes

This study isolated polysaccharides from strawberry (SP) and mulberry (MP) fruit juice to compare their cytokine secretion regulatory and antiapoptotic activities using murine primary splenocytes. SP and MP in the absence or presence of lipopolysaccharide (LPS) were administered to splenocytes for 48 hours. The culture supernatant was used for cytokine secretion assay using the enzyme-linked immunosorbent assay method. The cell pellet was used for the determination of anti-/proapoptotic protein (B cell lymphoma 2/Bak) levels in the cells using the Western blotting method. The results showed that SP and MP treatment at appropriate concentrations significantly increased the proliferation of splenocytes (p < 0.05). SP and MP treatments in the absence of LPS, and SP treatments in the presence of LPS significantly decreased T helper type 1/T helper type 2 (p < 0.05), and SP in the presence of LPS slightly decreased tumor necrosis factor-α/interleukin-10 (pro-/anti-inflammatory) cytokine secretion ratios by splenocytes, suggesting that SP has strong and MP has mild anti-inflammation potential via modulating cytokine secretion profiles. However, MP treatment at an appropriate concentration in the absence of LPS exhibited an antiapoptotic activity via modulating pro- (Bak) and antiapoptotic (B cell lymphoma 2) protein expression ratios, suggesting that MP may protect primary immune cells from apoptotic cell death. Overall, our findings suggest that SP has better anti-inflammation potential, whereas MP has better cell proliferation and antiapoptotic potential in vitro.     

Supercritical fluid extraction of oregano (Origanum vulgare) essentials oils: Anti-inflammatory properties based on cytokine response on THP-1 macrophages

Two fractions (S1 and S2) of an oregano (Origanum vulgare) extract obtained by supercritical fluid extraction have been used to test anti-inflammatory effects on activated human THP-1 cells. The main compounds present in the supercritical extract fractions of oregano were trans-sabinene hydrate, thymol and carvacrol. Fractions toxicity was assessed using the mitochondrial-respiration-dependent 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) reduction method for several concentrations during 24 and 48 h of incubation. Concentrations higher than 30 μg/mL of both supercritical S1 and S2 oregano fractions caused a reduction in cell viability in a dose-dependent manner. Oxidized-LDLs (oxLDLs) activated THP-1 macrophages were used as cellular model of atherogenesis and the release/secretion of cytokines (TNT-α, IL-1β, IL-6 and IL-10) and their respective mRNA expressions were quantified both in presence or absence of supercritical oregano extracts. The results showed a decrease in pro-inflammatory TNF-α, IL-1β and IL-6 cytokines synthesis, as well as an increase in the production of anti-inflammatory cytokine IL-10. These results may suggest an anti-inflammatory effect of oregano extracts and their compounds in a cellular model of atherosclerosis.     

Moclobemide exerts anti-inflammatory effect in lipopolysaccharide-activated primary mixed glial cell culture

An increasing body of evidence indicates that glial activation and neuroinflammation play an important role in the pathogenesis of psychiatric and neurodegenerative diseases. Activated glial cells secrete various cytokines that influence neurotransmission, hypothalamus–pituitary–adrenal axis activity, neuronal plasticity and neurogenesis. It has been suggested that alterations in cytokine networks are involved in the mechanism of action of antidepressant drugs. Until now, only a few studies demonstrated that some tricyclic antidepressants and selective serotonin reuptake inhibitors reduced production of pro-inflammatory cytokines in brain glia cells. We have investigated for the first time whether the antidepressant, moclobemide (a reversible selective inhibitor of monoamine oxidase-A) has an influence on pro-inflammatory cytokines [interleukin (IL)-1β and tumor necrosis factor (TNF)-α] and anti-inflammatory cytokine (IL-10) in primary rat mixed glial cell cultures stimulated by lipopolysaccharide (LPS). Our results showed that moclobemide used in a wide range of concentrations diminished LPS-stimulated IL-1β and TNF-α mRNAs expression in cellular extracts and remarkably reduced the levels of both pro-inflammatory cytokines in culture medium. In opposite to this, the drug had no influence on IL-10 mRNA and slightly reduced IL-10 concentration. Moreover, moclobemide decreased LPS-stimulated translocation of NFκB p65 subunit into cellular nuclei. These results suggest that moclobemide exerts anti-inflammatory effect in the central nervous system because it affects the balance between pro- and anti-inflammatory cytokines (IL-1β, TNF-α/IL-10) in primary mixed glial cell cultures.     

Lactobacillus helveticus HY7801 ameliorates vulvovaginal candidiasis in mice by inhibiting fungal growth and NF-κB activation

The anti-inflammatory effects of hydrogen peroxide-producing lactic acid bacteria (LAB) against Candida albicans-induced vulvovaginal candidiasis in β-estradiol-immunosuppressed mice were examined. Oral and intravaginal treatment with these LABs significantly decreased the level of viable C. albicans within the vaginal cavity as well as the quantitated myeloperoxidase activity in the vaginal tissues when compared with control untreated mice. Out of all of the LABs tested, Lactobacillus helveticus HY7801 (LH) most potently inhibited vulvovaginal candidiasis. LH also inhibited the expression of the pro-inflammatory cytokines including TNF-α, IL-1β and IL-6, and inflammatory enzymes, COX-2 and iNOS, as well as the activation of NF-κB. However, the addition of LH led to an increase in IL-10 cytokine expression in the vaginal tissues. In addition, the decrease of Lactobacillaceae and the increase of Pasteurellaceae caused by treatment with C. albicans were reversed with oral and intravaginal administration of LH, suggesting a potential shift in the vaginal microflora present. Addition of LH was toxic to C. albicans in vitro when cultured with HeLa cells. Oral administration of LH inhibited lipopolysaccharide (LPS)-induced TNF-α and IL-1β expressions in β-estradiol-immunosuppressed mice but reversed the expression of anti-inflammatory cytokine IL-10 in comparison to levels observed in the normal control group. LH also inhibited the expression of the pro-inflammatory cytokines, TNF-α and IL-1β, and the activation of NF-κB in LPS-stimulated peritoneal macrophages. Based on these findings, LH may ameliorate vulvovaginal candidiasis by suppressing the NF-κB pathway, as well as through inhibition of the growth of C. albicans.     

Cadmium-induced inflammatory responses in cells relevant for lung toxicity: Expression and release of cytokines in fibroblasts,epithelial cells and macrophages

Inhalation is an important route of cadmium (Cd) exposure, and the lung is considered to be one of the main target organs of Cd toxicity. Pulmonary inflammation seems to be involved in development of many lung diseases. In the present study we show that Cd²⁺ at fairly low concentrations affects gene expression of several different cytokines/chemokines in human M1 fibroblasts. The chemokines CXCL2, CXCL3, IL-8/CXCL8 and CCL26, the pro-inflammatory cytokine IL-6 and the receptor IL-1RL1 were expressed at high levels after exposure to 7 μM Cd²⁺ for 7 h. The expression of some important cytokines was further studied in two different primary cell cultures from rat lungs. Cd²⁺ induced cytokine responses at low concentrations (3–6 μM) and early time-points both in type 2 epithelial cell-enriched cultures and alveolar macrophages. However, the two primary lung cells displayed different patterns of cytokine release. Cd²⁺ induced an increased release of IL-6 and MIP-2/CXCL2 from the epithelial cells and MIP-2, IL-1β and TNF-α from alveolar macrophages. In conclusion, the marked up-regulation of different cytokines in these cell types, that are important in development of lung injury and disease, suggests that inflammation may contribute in Cd-induced lung damage.     

Targeting V-ATPase in primary human monocytes by archazolid potently represses the classical secretion of cytokines due to accumulation at the endoplasmic reticulum

The macrolide archazolid inhibits vacuolar-type H(+)-ATPase (V-ATPase), a proton-translocating enzyme involved in protein transport and pH regulation of cell organelles, and potently suppresses cancer cell growth at low nanomolar concentrations. In view of the growing link between inflammation and cancer, we investigated whether inhibition of V-ATPase by archazolid may affect primary human monocytes that can promote cancer by sustaining inflammation through the release of tumor-promoting cytokines. Human primary monocytes express V-ATPase, and archazolid (10–100 nM) increases the vesicular pH in these cells. Archazolid (10 nM) markedly reduced the release of pro-inflammatory (TNF-α, interleukin-6 and -8) but also of anti-inflammatory (interleukin-10) cytokines in monocytes stimulated with LPS, without affecting cell viability up to 1000 nM. Of interest, secretion of interleukin-1β was increased by archazolid. Comparable effects were obtained by the V-ATPase inhibitors bafilomycin and apicularen. The phosphorylation of p38 MAPK and ERK-1/2, Akt, SAPK/JNK or of the inhibitor of NFκB (IκBα) as well as mRNA expression of IL-8 were not altered by archazolid in LPS-stimulated monocytes. Instead, archazolid caused endoplasmic reticulum (ER) stress response visualized by increased BiP expression and accumulation of IL-8 (and TNF-α) at the ER, indicating a perturbation of protein secretion. In conclusion, by interference with V-ATPase, archazolid significantly affects the secretion of cytokines due to accumulation at the ER which might be of relevance when using these agents for cancer therapy.     

Dehydrocorydaline inhibits elevated mitochondrial membrane potential in lipopolysaccharide-stimulated macrophages

Activated macrophages play a critical role in the pathogenesis of numerous diseases by producing pro-inflammatory cytokines such as interleukin (IL)-1β and IL-6. While the mechanisms of bacterial component recognition and signal transduction have been well investigated, viability regulation in activated macrophages remains unclear. We screened herbal ingredients to find an agent that reduces the viability of lipopolysaccharide (LPS)-stimulated macrophages and observed that dehydrocorydaline, a component of Corydalis yanhusuo, reduced the viability of macrophage-derived RAW264.7 cells and primary macrophages in the presence of LPS. Dehydrocorydaline inhibited the elevation of mitochondrial membrane potential and induced ATP depletion in LPS-stimulated macrophages but neither affected basal mitochondrial membrane potential nor ATP content in non-stimulated macrophages. Dehydrocorydaline also prevented increased concentrations of IL-1β and IL-6 in culture media of LPS-stimulated macrophages. Mode of dehydrocorydaline action indicates that elevated mitochondrial membrane potential may be a novel target to specifically reduce viability and suppress cytokine production in LPS-stimulated macrophages.     

In vivo uptake and acute immune response to orally administered chitosan and PEG coated PLGA nanoparticles

Nanoparticulate drug delivery systems offer great promise in addressing challenges of drug toxicity, poor bioavailability and non-specificity for a number of drugs. Much progress has been reported for nano drug delivery systems for intravenous administration, however very little is known about the effects of orally administered nanoparticles. Furthermore, the development of nanoparticulate systems necessitates a thorough understanding of the biological response post exposure. This study aimed to elucidate the in vivo uptake of chitosan and polyethylene glycol (PEG) coated Poly, dl, lactic-co-glycolic Acid (PLGA) nanoparticles and the immunological response within 24 h of oral and peritoneal administration. These PLGA nanoparticles were administered orally and peritoneally to female Balb/C mice, they were taken up by macrophages of the peritoneum. When these particles were fluorescently labelled, intracellular localisation was observed. The expression of pro-inflammatory cytokines IL-2, IL-6, IL-12p70 and TNF-α in plasma and peritoneal lavage was found to remain at low concentration in PLGA nanoparticles treated mice as well as ZnO nanoparticles during the 24 hour period. However, these were significantly increased in lipopolysaccharide (LPS) treated mice. Of these pro-inflammatory cytokines, IL-6 and IL-12p70 were produced at the highest concentration in the positive control group. The anti-inflammatory cytokines IL-10 and chemokines INF-γ, IL-4, IL-5 remained at normal levels in PLGA treated mice. IL-10 and INF-γ were significantly increased in LPS treated mice. MCP-1 was found to be significantly produced in all groups in the first hours, except the saline treated mice. These results provide the first report to detail the induction of cytokine production by PLGA nanoparticles engineered for oral applications.     

Ginsenoside Rg5 ameliorates lung inflammation in mice by inhibiting the binding of LPS to toll-like receptor-4 on macrophages

Heating and steaming processes have been applied to various natural medicines for either enhancing or altering their pharmacological activities, and the chemical compositions of the active components. While ginsenoside Rb1, which is the major constituent of raw ginseng, has been studied extensively for its anti-inflammatory effect, the biological activity of ginsenoside Rg5, a major constituent of steamed ginseng, remains to be explored. Here, we isolated Rg5 and examined anti-inflammatory effect in lipopolysaccharide (LPS)-stimulated macrophages and on LPS-induced lung inflammation. Rg5 inhibited the expression of proinflammatory cytokines, IL-1β and TNF-α, as well as inflammatory enzymes, COX-2 and iNOS in LPS-stimulated alveolar macrophages. Rg5 also reduced LPS-induced phosphorylation of IL-1 receptor-associated kinases (IRAK)-1 and IKK-β, as well as the degradation of IRAK-1 and IRAK-4. Rg5 inhibited the phosphorylation of NF-κB as well as the translocation of p65 into the nucleus. When macrophages were treated with Alexa Fluor 594-conjugated LPS in the presence of Rg5, the fluorescence intensity of LPS observed outside the cell membrane was lower than that in LPS-stimulated alveolar macrophages alone. Rg5, inhibited the levels of protein and neutrophils in bronchoalveolar lavage fluid of LPS-stimulated mice, as well as pro-inflammatory cytokines, TNF-α and IL-1β. Rg5 also inhibited iNOS and COX expressions, and NF-κB activation in LPS-stimulated lung inflammation of mice. The inhibitory effect of Rg5 (10 mg/kg) was comparable to that of dexamethasone (5 mg/kg). Based on these findings, Rg5 can ameliorate lung inflammation possibly by inhibiting the binding of LPS to toll-like receptor (TLR)-4 on macrophages.     

Anti-inflammatory and antifibrotic effects of methyl palmitate

Methyl palmitate (MP) has been shown earlier to inhibit Kupffer cells and rat peritoneal macrophages. To evaluate the potential of MP to inhibit the activation of other macrophages, RAW cells (macrophages of alveolar origin) were treated with varying concentrations of MP (0.25, 0.5, 1 mM). Assessment of cytotoxicity using MTT assay revealed that 0.25 and 0.5 mM are not toxic to RAW cells. MP was able to inhibit the phagocytic function of RAW cells. Treatment of cells with MP 24 hours prior to LPS stimulation significantly decreased nitric oxide release and altered the pattern of cytokines release; there was a significant decrease in TNF-α and a significant increase in IL-10 compared to the controls. However, there is a non-significant change in IL-6 level. Furthermore, phosphorylation of inhibitory kappa B (IκBα) protein was significantly decreased in RAW cells treated with 0.5 mM MP after LPS stimulation. Based upon the in-vitro results, it was examined whether MP treatment will be effective in preventing bleomycin-induced lung inflammation and fibrosis in-vivo. Bleomycin given by itself caused destruction of the lung architecture characterized by pulmonary fibrosis with collapse of air alveoli and emphysematous. Bleomycin induced a significant increase in hydroxyproline level and activated NF-κB, p65 expression in the lung. MP co-treatment significantly ameliorated bleomycin effects. These results suggest that MP has a potential of inhibiting macrophages in general. The present study demonstrated for the first time that MP has anti-inflammatory and antifibrotic effect that could be through NF-kB inhibition. Thus MP like molecule could be a promising anti-inflammatory and antifibrotic drug.     

Impact of perfluorooctanesulfonate and perfluorooctanoic acid on human peripheral leukocytes

Perfluorinated compounds (PFCs), such as perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA), are xenobiotics that can be detected worldwide in the environment, wildlife, and humans. So far, the immunotoxicity of PFCs has only been investigated in rodents, but not in humans. In this study, we explore the impact of PFOS and PFOA on selected functions of human leukocytes in vitro. PFOS induced a significant decrease of natural killer-cell activity and reduced the release of the pro-inflammatory cytokine TNF-α following lipopolysaccharide (LPS)-stimulation. Furthermore, the plasma PFOS concentrations (2.09-8.98 ng/ml) found in our study subjects correlated positively with the LPS-stimulated IL-6 release. PFOA augmented significantly calcitriol-induced monocytic differentiation of the HL-60 cell line. Additionally, there was a significant linear relationship between LPS-stimulated TNF-α and IL-6 release, and the plasma PFOA (1.20-6.92 ng/ml) concentrations of the study subjects. In conclusion, the investigated PFCs affect human immune cells mainly with regard to natural killer-cell cytotoxicity and the pro-inflammatory cytokine release by stimulated macrophages.     

Statins as modulators of colon cancer cells induced cytokine secretion by human PBMC

The study was designed to examine whether the hydrophilic statin - pravastatin and the hydrophobic statin - simvastatin affect colon cancer cell-induced cytokine secretion by peripheral blood mononuclear cells (PBMC). Statins were added to human colon cancer cells (HT-29 and RKO), or to PBMC incubated separately or jointly. The secretion of the pro-inflammatory cytokines IL-1β and IFNγ and that of the anti-inflammatory cytokines IL-1ra and IL-10 induced by cancer cells was decreased by simvastatin but not by pravastatin, whereas that of IL-6 was not affected by both drugs. Conditioned media from colon cancer cells incubated with either simvastatin or pravastatin induced stimulation of cytokine production by PBMC similar to that caused by conditioned media derived from cancer cells incubated without the drugs, suggesting that simvastatin acts directly on the interaction between cancer and PBM cells. Simvastatin, but not pravastatin, caused inhibition of both cancer cell proliferation. The results imply that simvastatin may affect inflammation-induced colon cancer proliferation via alteration of the equilibrium between pro- and anti-inflammatory cytokines.     

Suppression of miR-21 and miR-155 of macrophage by cinnamaldehyde ameliorates ulcerative colitis

Ulcerative colitis (UC) is a major form of inflammatory bowel disease which involved mucosal immune dysfunction. Cinnamaldehyde (CA) is major active compound from cinnamon, a useful traditional medicine in Asia which shows superior antibacterial and anti-inflammatory activity. In this study, we investigated the effects of CA on UC both in vivo and in vitro. We showed that CA attenuated the symptoms of DSS-induced colitis, including loss of body weights, disease activity index (DAI), shortening of the colon lengths and infiltration of inflammatory cells. Moreover, CA decreased the pro-inflammatory cytokines and NLRP3 inflammasome, miR-21 and miR-155 in colon tissues, in addition, the percentage of macrophages was reduced based on the surface marker F4/80 and IL-10 secretion in CA-treated group, suggesting that the CA ameliorate the UC via activation of macrophage. Herein, the effects of CA on macrophage cells were examined in vitro. We found that CA reduced the level of proinflammatory cytokines, such as TNF-α, IL-1β, IL-6, in the activation of RAW264.7, human macrophage-like cells U937, and primary peritoneal macrophages. Furthermore, the suppression of NLRP3 inflammasome, miR-21 and miR-155 was also found in CA-treated LPS-stimulated RAW264.7 cells. CA also reduced the production of reactive oxygen species, the phosphorylation of AKT, mTOR and COX2 protein level in the RAW264.7. Meanwhile, data revealed that transferred miR-21 or miR-155 inhibitor suppressed levels of IL-1β and IL-6, whereas miR-21 or miR-155 mimics increased expressions of these, and CA suppressed these expressions. Our results indicate that CA could ameliorate DSS-induced colitis through inhibition of NLRP3 inflammasome activation and miR-21 and miR-155 levels in colons and macrophage, suggesting that CA might be a potentially effective drug for UC.     

Modulation of Inflammatory Cytokines and Mitogen-activated Protein Kinases by Acetate in Primary Astrocytes

Acetate supplementation attenuates neuroglia activation in a rat model of neuroinflammation by a mechanism associated with an increase in brain acetyl-CoA, an alteration in histone acetylation, and reduction of interleukin (IL)-1β expression. We propose that reduced astroglial activation occurs by disrupting astrocyte-derived inflammatory signaling and cytokine release. Using primary astroglial cultures, we found that LPS (0–25 ng/ml, 4 h) increased tumor necrosis factor (TNF-α) and IL-1β in a concentration-dependent manner, which was reduced by treatment with sodium acetate (12 mM). LPS did not alter H3K9 acetylation or IL-6 levels, whereas acetate treatment increased H3K9 acetylation by 2-fold and decreased basal levels of IL-6 by 2-fold. Acetate treatment attenuated the LPS-induced increase in TNF-α mRNA, but did not reverse the mRNA levels of other pro-inflammatory cytokines. By contrast, LPS decreased TGF-β1 and IL-4 protein and TGF-β1 mRNA, all of which was reversed with acetate treatment. Further, we found that acetate treatment completely reversed LPS-induced phosphorylation of MAPK p38 and decreased basal levels of phosphorylated extracellular signal-regulated kinases1/2 (ERK1/2) by 2-fold. Acetate treatment also reversed LPS-elevated NF-κB p65, CCAAT/enhancer-binding protein beta protein levels, and reduced basal levels of phosphorylated NF-κB p65 at serine 536. These results suggest that acetate treatment has a net anti-inflammatory effect in LPS-stimulated astrocytes that is largely associated with a disruption in MAPK and NF-κB signaling.     

Insights of local tissue damage and regeneration induced by BnSP-7, a myotoxin isolated from Bothrops (neuwiedi) pauloensis snake venom

Envenomations caused by Bothrops snake venoms are characterized by prominent local tissue damage due to myonecrosis, hemorrhage, edema and acute muscle damage which is widely correlated with phospholipases A₂ (PLA₂). In the present study, the progression of local tissue damage and inflammation induced by BnSP-7, a myotoxin isolated from Bothrops (neuwiedi) pauloensis snake venom, was evaluated. Local tissue damages characterized by edema, necrosis and inflammation were evaluated until 24 h after inoculation of BnSP-7. The regeneration of myofibers, analyzed by light microscopy, was observed from 72 h to 2 weeks post-inoculation of toxin. MMP-2 was expressed in gastrocnemius muscle at all time points tested, while the expression of MMP-9 increased expressively at the same time interval of regenerating muscle, suggesting the involvement of MMP-9 in the regeneration process. The production of pro-inflammatory cytokines was also increased, whereas IL-1β showed the highest level. Modification of BnSP-7 with BPB decreased the release of IL-8, IL-6 and IL-1β when compared to native BnSP-7. These data suggest that BnSP-7 acts as pro-inflammatory incentives (mediators), inducing MMP and cytokine production from the inflammatory and satellite cells, and thus it may play an important role in inflammatory process and, consequently, in the evolution of local tissue damage and regeneration.     

Echinocystic acid,a metabolite of lancemaside A,inhibits TNBS-induced colitis in mice

The rhizome of Codonopsis lanceolata (CL, family Campanulaceae), of which the main constituent is lancemaside A, has been used for cough and bronchitis in traditional Chinese medicine. To evaluate anti-colitic effect of CL, we examined anti-inflammatory effect of CL extracts, lancemaside A and its metabolites in lipopolysaccharide (LPS)-stimulated peritoneal macrophages and 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitic mice. Among CL extracts, CL BuOH extract inhibited LPS-induced IL-1β, IL-6 and TNF-α expression, as well as NF-κB activation most potently. CL BuOH extract also inhibited colon shortening and myeloperoxidase activity in TNBS-induced colitic mice. Among lancemaside A, a main constituent of CL BuOH extract, and its metabolites (lancemaside X, echinocystic acid-3-O-β-d-glucopyranoside and echinocystic acid), echinocystic acid inhibited the expression of the pro-inflammatory cytokines, IL-1β, IL-6, and TNF-α, as well as the phosphorylation of IKKβ and p65 in LPS-stimulated peritoneal macrophages most potently. Echinocystic acid also potently inhibited the binding of LPS to TLR4 on peritoneal macrophages. Lancemaside A and its metabolite, echinocystic acid, inhibited TNBS-induced colonic inflammation, including colon shortening, increased myeloperoxidase activity and pro-inflammatory cytokine expression, and NF-κB activation in mice. The anti-colitic effect of echinocystic acid was superior to that of lancemaside A. Based on these findings, orally administered lancemaside A may be metabolized to echinocystic acid, which may express anti-colitic effect by inhibiting the binding of LPS to TLR4 on the macrophages.     

Dihydropyranoaurone compound damaurone D inhibits LPS-induced inflammation and liver injury by inhibiting NF-κB and MAPK signaling independent of AMPK

Recently, we reported the synthesis of damaurone D (DD), originally derived from Rosa damascene, and its anti-inflammatory effect in macrophages. Here, we investigated the molecular mechanism underlying the anti-inflammatory effect of DD in macrophages and further tested whether DD is protective against lipopolysaccharide (LPS)-induced liver injury. DD inhibited LPS-stimulated expression of pro-inflammatory genes and cytokine/chemokine secretion in a concentration-dependent manner in RAW 264.7 cells and thioglycolate-elicited mouse peritoneal macrophages. DD suppressed LPS-stimulated nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways, as demonstrated by reduction in IκB kinase α/β phosphorylation, IκBα degradation, and levels of phosphorylated ERK, JNK, and p38 MAPK. The luciferase reporter activity of NF-κB and activator protein 1 was also attenuated by DD pretreatment. Furthermore, DD treatment induced AMP-activated protein kinase (AMPK) activation in cells and mouse liver, although the anti-inflammatory effect of DD was similar in dominant-negative AMPK-overexpressing cells. Lastly, DD-treated mice were protected against LPS-induced acute liver injury, based on morphologic and immunohistochemical observations; reduction in the plasma levels of aspartate aminotransferase, TNF-α, and MCP-1; and a decrease in inflammatory gene expression. In summary, our findings indicate that DD can protect against LPS-stimulated inflammation and liver injury at least partly by suppression of NF-κB and MAPK signaling pathways.