Anti-inflammatory activity of Angelica dahurica ethanolic extract on RAW264.7 cells via upregulation of heme oxygenase-1

Ex Vivo and In Situ Evaluation of 'Dispelling-Wind' Chinese Medicine Herb-Drugs on Intestinal Absorption of Chlorogenic Acid

This study aims to investigate the additive or synergistic effects and mechanism of intestinal absorption of extracts from two commonly used 'dispelling-wind' TCM botanical drugs [roots of Angelica dahurica (Hoffm.) Benth. & Hook. f. ex Franch. & Sav. (RAD) and Saposhnikovia divaricata (Turcz.) Schischk. (RSD)] using chlorogenic acid as a marker substance. Ex vivo everted intestinal sac and in situ single pass perfusion methods using rats were employed to investigate the effects of two TCM botanical drugs extracts on the intestinal absorption of chlorogenic acid. Both the extracts of RAD and RSD showed synergistic properties on the intestinal absorption of chlorogenic acid. The verapamil (a P-gp inhibitor) and intestinal dysbacteriosis model induced by norfloxacin increased the P(app) and K(a) of intestinal absorption of chlorogenic acid. These synergistic effects on intestinal absorption in a rat model can be correlated with the inhibition of P-gp and regulation of gut microbiota. This experimental approach has helped to better understand changes in the absorption of chlorogenic acid under different conditions.

Molecular mechanism of a new Laminaria japonica polysaccharide on the suppression of macrophage foam cell formation via regulating cellular lipid metabolism and suppressing cellular inflammation

SCOPE

Laminaria japonica is an important marine vegetable with great health benefits for preventing atherosclerosis. Since the foam cell formation is an important hallmark for the initiation of atherosclerosis, we examined the effect and underlying mechanism of a purified L. japonica polysaccharide (LJP61A) on the suppression of macrophage foam cell formation in this study. The chemical structure was further characterized.

METHODS AND RESULTS

Using oxidized low-density lipoprotein (ox-LDL)-induced foam cell model, we found that the cellular lipid accumulation was significantly attenuated by 25 μg/mL LJP61A. Meanwhile, LJP61A caused a remarkable decrease in mRNA expression of peroxisome proliferator-activated receptor γ that was accompanied by the reduction of CD36 and Acyl coenzyme A: cholesterol acyltransferase-1 mRNA levels, and the enhancement of ATP-binding cassette transporters A1 and scavenger receptor B1 mRNA levels. Besides these, the ox-LDL-induced cellular inflammation was also restricted by LJP61A treatment via mammalian target of rapamycin-mediated Toll-like receptor 2/4-Mitogen-activated protein kinases/nuclear factor kappa-B pathways. The structure of LJP61A was characterized as a repeating unit consisting of →3,6)-α-d-Manp-(1→, →4)-α-d-Manp-(1→, →4)-2-O-acetyl-β-d-Glcp-(1→, →4)-β-d-Glcp-(1→, →6)-4-O-SO3 -β-d-Galp-(1→, →6)-β-d-Galp-(1→, →3)-β-d-Galp-(1→, and a terminal residue of α-d-Glcp-(1→.

CONCLUSION

Our findings suggest that LJP61A inhibits the conversion of macrophage into foam cell via regulating cellular lipid metabolism and suppressing cellular inflammation.

Anti-inflammatory dimeric furanocoumarins from the roots of Angelica dahurica

Seven new dimeric furanocoumarins, dahuribiethrins A-G (1-7), were isolated from the roots of Angelica dahurica. Their structures were determined by chemical derivatization and extensive spectroscopic techniques, including (1)H NMR, (13)C NMR, HSQC, (1)H-(1)H COSY, HMBC, and NOESY experiments. Compounds 2, 3, 4, and 5 exhibited significant inhibition of nitric oxide production in the lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells with IC50 values in the range of 8.8-9.8 μM.

Antioxidative dietary compounds modulate gene expression associated with apoptosis, DNA repair, inhibition of cell proliferation and migration

Many dietary compounds are known to have health benefits owing to their antioxidative and anti-inflammatory properties. To determine the molecular mechanism of these food-derived compounds, we analyzed their effect on various genes related to cell apoptosis, DNA damage and repair, oxidation and inflammation using in vitro cell culture assays. This review further tests the hypothesis proposed previously that downstream products of COX-2 (cyclooxygenase-2) called electrophilic oxo-derivatives induce antioxidant responsive elements (ARE), which leads to cell proliferation under antioxidative conditions. Our findings support this hypothesis and show that cell proliferation was inhibited when COX-2 was down-regulated by polyphenols and polysaccharides. Flattened macrophage morphology was also observed following the induction of cytokine production by polysaccharides extracted from viili, a traditional Nordic fermented dairy product. Coix lacryma-jobi (coix) polysaccharides were found to reduce mitochondrial membrane potential and induce caspase-3- and 9-mediated apoptosis. In contrast, polyphenols from blueberries were involved in the ultraviolet-activated p53/Gadd45/MDM2 DNA repair system by restoring the cell membrane potential. Inhibition of hypoxia-inducible factor-1 by saponin extracts of ginsenoside (Ginsen) and Gynostemma and inhibition of S100A4 by coix polysaccharides inhibited cancer cell migration and invasion. These observations suggest that antioxidants and changes in cell membrane potential are the major driving forces that transfer signals through the cell membrane into the cytosol and nucleus, triggering gene expression, changes in cell proliferation and the induction of apoptosis or DNA repair.

The role of interleukin family in perfluorooctanoic acid (PFOA)-induced immunotoxicity

Perfluorooctanoic acid (PFOA), a prominent perfluorinated compound (PFC), has been widely detected in natural water bodies worldwide. In this study, zebrafish (Danio rerio) was exposed to nominal concentrations of PFOA (0.05, 0.1, 0.5, and 1 mg/L) for 21 d. After exposure, each fish was decapitated, and the spleen was removed to detect the expression patterns of P65 transcription factor, myeloid differentiation 88, relative interleukins (ILs), and antibody genes. PFOA can stimulate pro-inflammatory cytokine at a low exposure concentration (0.05 mg/L) and can inhibit pro-inflammatory cytokine at higher exposure concentrations (≥ 0.1mg/L). The results of linear correlation analysis indicate that Myd88/NF-κB pathway is one of the important pathways to mediate inflammatory cytokine (IL-1β and IL-21) in zebrafish spleen. Additionally, the relative mRNA expression level of toll-like receptor 2 (TLR2) at 1mg/L PFOA group was decreased to 56% of its corresponding level in the control. IL secretion disorder is possibly closely related to PFOA-induced TLR2 damage in zebrafish spleen. Furthermore, data show that the trends of PFOA-induced IL secretion have a relationship with Ig-secreting trend. This study demonstrates that PFOA can affect IL expression level through NF-κB, and ILs have an important function in the mediation of Ig secretion.

Anti-inflammatory effects of Siegesbeckia orientalis ethanol extract in in vitro and in vivo models

This study aims to investigate the anti-inflammatory responses and mechanisms of Siegesbeckia orientalis ethanol extract (SOE). In cell culture experiments, RAW264.7 cells were pretreated with SOE and stimulated with lipopolysaccharide (LPS) for inflammatory mediators assay. In animal experiments, mice were tube-fed with SOE for 1 week, and s.c. injected with λ-carrageenan or i.p. injected with LPS to simulate inflammation. The degree of paw edema was assessed, and cytokine profile in sera and mouse survival were recorded. Data showed that SOE significantly reduced NO, IL-6, and TNF-α production in LPS-stimulated RAW264.7 cells. In vivo studies demonstrated that mice supplemented with 32 mg SOE/kg BW/day significantly lowered sera IL-6 level and resulted a higher survival rate compared to the control group (P = 0.019). Furthermore, SOE inhibited LPS-induced NF-κB activation by blocking the degradation of IκB-α. The SOE also reduced significantly the phosphorylation of ERK1/2, p38, and JNK in a dose-dependent manner. In summary, the in vitro and in vivo evidence indicate that SOE can attenuate acute inflammation by inhibiting inflammatory mediators via suppression of MAPKs- and NF-κB-dependent pathways.

Imperatorin induces Mcl-1 degradation to cooperatively trigger Bax translocation and Bak activation to suppress drug-resistant human hepatoma

Imperatorin is a small molecule nature compound isolated from the root of Angelica dahurica, and has been shown to exhibit multiple bioeffector functions, including anti-cancer activity. However, the molecular mechanism underlying imperatorin in suppression of tumor growth is unknown. In this study, we aimed at elucidating the molecular mechanisms underlying imperatorin function and determining the efficacy of imperatorin in suppression of drug-resistant human liver cancer. We observed that imperatorin suppresses tumor cell growth through inducing apoptosis, and imperatorin is more effective in induction of multidrug-resistant human liver cancer cells in vitro. We further determined that imperatorin induces apoptosis through both extrinsic and intrinsic apoptosis pathway. At the molecular level, we identified Mcl-1 as the molecular target of imperatorin and determined that imperatorin induces proteosome-dependent Mcl-1 degradation to release Bak and Bax to trigger apoptosis in liver cancer cells. Consistent with its in vitro apoptosis induction activity, imperatorin exhibited potent activity against multidrug-resistant liver cancer xenograft growth in vivo. Taken together, we determined that imperatorin is a Mcl-1 degradation inducer that can effectively suppress multidrug-resistant human liver cancer growth in vivo, and thus holds great promise for development as an effective small molecule anti-cancer agent in human liver cancer therapy to overcome drug resistance.

Anti-inflammatory effect of methanol extract from Erigeron Canadensis L. may be involved with upregulation of heme oxygenase-1 expression and suppression of NFκB and MAPKs activation in macrophages

BACKGROUND/OBJECTIVES

In this study, we determined the anti-inflammatory activities and the underlying molecular mechanisms of the methanol extract from Erigeron Canadensis L. (ECM) in LPS-stimulated RAW264.7 macrophage cells.

MATERIALS/METHODS

The potential anti-inflammatory properties of ECM were investigated by using RAW264.7 macrophages. We used western blot assays and real time quantitative polymerase chain reaction to detect protein and mRNA expression, respectively. Luciferase assays were performed to determine the transactivity of transcription factors.

RESULTS

ECM significantly inhibited inducible nitric oxide synthase (iNOS)-derived NO and cyclooxygenase-2 (COX-2) derived PGE2 production in LPS-stimulated RAW264.7 macrophages. These inhibitory effects of ECM were accompanied by decreases in LPS-induced nuclear translocations and transactivities of NFκB. Moreover, phosphorylation of mitogen-activated protein kinase (MAPKs) including extracellular signal-related kinase (ERK1/2), p38, and c-jun N-terminal kinase (JNK) was significantly suppressed by ECM in LPS-stimulated RAW264.7 macrophages. Further studies demonstrated that ECM by itself induced heme oxygenase-1 (HO-1) protein expression at the protein levels in dose-dependent manner. However, zinc protoporphyrin (ZnPP), a selective HO-1 inhibitor, abolished the ECM-induced suppression of NO production.

CONCLUSIONS

These results suggested that ECM-induced HO-1 expression was partly responsible for the resulting anti-inflammatory effects. These findings suggest that ECM exerts anti-inflammatory actions and help to elucidate the mechanisms underlying the potential therapeutic values of Erigeron Canadensis L.

Nitric oxide and interleukins are involved in cell proliferation of RAW264.7 macrophages activated by viili exopolysaccharides

Viili has been traditionally regarded as healthy food; viili exopolysaccharides (VEPS) function as antioxidants, but the molecular and cellular mechanisms, especially its immune functions, remain largely unclear. To assess VEPS's immunological roles, VEPS were separated by Sevage's method and purified by anion exchange chromatography. Cell proliferation, phagocytosis, releases of nitric oxide (NO), interleukin (IL)-1β, and IL-6, the inducible nitric oxide synthase (iNOS) gene expression by reverse transcription polymerase chain reaction (RT-PCR) and iNOS protein by Western blotting, and morphology by scanning electron microscopy in lipopolysaccharides (LPS)/VEPS-stimulated and non-stimulated RAW264.7 macrophages were analyzed. VEPS increased cell proliferation at 50-200 μg/mL. The uptake of neutral red for the indication of phagocytosis and releases of NO, IL-6, and IL-1β were enhanced after exposure to LPS and VEPS. Gene expressions of iNOS, IL-6, and IL-1β and protein expressions of iNOS were increased with VEPS. The RAW264.7 cell treated with VEPS became flattened, a strong indication of the activation of macrophages. We concluded that VEPS promoted the activation of macrophages in which NO, IL-6, and IL-1β were involved; the release of NO and other cytokines may eventually activate lymphocytes, increasing nonspecific (innate) and specific immunity in humans.

Molecular mechanism of anti-inflammatory activity of Pluchea indica leaves in macrophages RAW 264.7 and its action in animal models ofinflammation

ETHNOPHARMACOLOGICAL RELEVANCE

PLUCHEA INDICA LESS.: (Asteraceae) is a Thai medicinal plant used in traditional medicine for the treatment of hemorrhoids, lumbago, leucorrhoea and inflammation. This study investigated the molecular mechanism of anti-inflammatory activity of Pluchea indica leaf extract in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages and also determined its action in acute inflammation animal models.

MATERIALS AND METHODS

The inhibitory effect of Pluchea indica leaf extract on LPS-induced nitric oxide (NO) production was evaluated by Griess reaction. Protein and mRNA expressions were determined by real time RT-PCR and Western blotting analysis, respectively. Inducible nitric oxide synthase (iNOS) promoter activity was evaluated by iNOS promoter based reporter gene assay. In vivo anti-inflammatory effect was examined in ethylphenylpropiolate (EPP)-induced ear edema and carrageenan-induced paw edema in rat models.

RESULTS

Ethyl acetate fraction of ethanol extract of Pluchea indica leaves (EFPI) exhibited the potent inhibitory effect on NO production in LPS-induced macrophages and also inhibited PGE2 release. EFPI reduced iNOS mRNA and protein expression through suppressed iNOS promoter activity and nuclear translocation of subunit p65 of nuclear factor-κB, but did not inhibit phosphorylation of the mitogen-activated protein kinases (MAPKs). Moreover, EFPI possessed anti-inflammatory activities on acute phase of inflammation as seen in EPP-induced ear edema and carrageenan-induced paw edema inrats.

CONCLUSIONS

These data support the pharmacological basis of Pluchea indica plant as a traditional herbal medicine for treatment of inflammation.

Effect of kramecyne on the inflammatory response in lipopolysaccharide-stimulated peritoneal macrophages

Kramecyne is a new peroxide, it was isolated from Krameria cytisoides, methanol extract, and this plant was mostly found in North and South America. This compound showed potent anti-inflammatory activity; however, the mechanisms by which this compound exerts its anti-inflammatory effect are not well understood. In this study, we examined the effects of kramecyne on inflammatory responses in mouse lipopolysaccharide- (LPS-) induced peritoneal macrophages. Our findings indicate that kramecyne inhibits LPS-induced production of tumor necrosis factor (TNF-α) and interleukin- (IL-) 6. During the inflammatory process, levels of cyclooxygenase- (COX-) 2, nitric oxide synthase (iNOS), and nitric oxide (NO) increased in mouse peritoneal macrophages; however, kramecyne suppressed them significantly. These results provide novel insights into the anti-inflammatory actions and support its potential use in the treatment of inflammatory diseases.

Lucidone suppresses hepatitis C virus replication by Nrf2-mediated heme oxygenase-1 induction

Upon screening of plant-derived natural products against hepatitis C virus (HCV) in the replicon system, we demonstrate that lucidone, a phytocompound, isolated from the fruits of Lindera erythrocarpa Makino, significantly suppressed HCV RNA levels with 50% effective concentrations of 15 ± 0.5 μM and 20 ± 1.1 μM in HCV replicon and JFH-1 infectious assays, respectively. There was no significant cytotoxicity observed at high concentrations, with a 50% cytotoxic concentration of 620 ± 5 μM. In addition, lucidone significantly induced heme oxygenase-1 (HO-1) production and led to the increase of its product biliverdin for inducing antiviral interferon response and inhibiting HCV NS3/4A protease activity. Conversely, the anti-HCV activity of lucidone was abrogated by blocking HO-1 activity or silencing gene expression of HO-1 or NF-E2-related factor 2 (Nrf2) in the presence of lucidone, indicating that the anti-HCV action of lucidone was due to the stimulation of Nrf-2-mediated HO-1 expression. Moreover, the combination of lucidone and alpha interferon, the protease inhibitor telaprevir, the NS5A inhibitor BMS-790052, or the NS5B polymerase inhibitor PSI-7977, synergistically suppressed HCV RNA replication. These findings suggest that lucidone could be a potential lead or supplement for the development of new anti-HCV agent in the future.

Evaluation of acute skin irritation and phototoxicity by aqueous and ethanol fractions of Angelica keiskei

In this study, to assess whether aqueous and ethanol fractions of Angelica keiskei induce acute skin irritation and phototoxicity, acute skin irritancy and phototoxicity tests were performed. The skin of rabbits or guinea pigs was treated with these fractions (100 mg/dose) and whether the animals sustained significant skin damage was determined. The data demonstrated that the aqueous and ethanol fractions of Angelica keiskei did not induce acute toxicity in the skin of the animals, as assessed by anatomical and pathological observations. The results from the present study suggest that these aqueous and ethanol fractions of Angelica keiskei have promising potential uses as cosmetic ingredients that do not induce significant levels of skin irritation or phototoxicity.

Anti-inflammatory effect of fucoxanthin derivatives isolated from Sargassum siliquastrum in lipopolysaccharide-stimulated RAW 264.7 macrophage

In this study, the anti-inflammatory effect of fucoxanthin (FX) derivatives, which was isolated from Sargassum siliquastrum were evaluated by examining their inhibitory effects on pro-inflammatory mediators in lipopolysaccharide (LPS)-stimulated murine macrophage RAW 264.7 cells. The FX derivatives were isolated from activity-guided chloroform fraction using inhibition of nitric oxide (NO) production and identified as 9'-cis-(6'R) fucoxnathin (FXA), and 13-cis and 13'-cis-(6'R) fucoxanthin complex (FXB) on the basis of a comparison of NMR spectroscopic data. Both FXA and FXB significantly inhibited the NO production and showed slightly reduce the PGE2 production. However, FXB exhibited cytotoxicity at the whole tested concentration, therefore, the results of FXA was only illustrate for further experiments. FXA induced dose-dependent reduction in the inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) proteins as well as mRNA expression. In addition, FXA reduced the LPS-stimulated production and mRNA expressions of TNF-α and IL-6 in a dose-dependent manner whereas IL-1β production do not inhibit by addition of FXA. Taken together, these findings indicate that the anti-inflammatory properties of FXA may be due to the inhibition of iNOS/NO pathway which associated with the attenuation of TNF-α and IL-6 formation. Thus FXA may provide a potential therapeutic approach for inflammation related diseases.

Polysaccharide fractions of Caesalpinia ferrea pods: potential anti-inflammatory usage

ETHNOPHARMACOLOGICAL RELEVANCE

Caesalpinia ferrea (Caesalpinioideae), known as pau-ferro or juca, has been used in the traditional medicine in North and Northeast of Brazil in inflammatory disorder, among others. Thus, experimental evaluation of the anti-inflammatory activity of extracts and fraction polysaccharides of Caesalpinia ferrea pods, and correlation with its anti-inflammatory activity and popular use is important.

MATERIALS AND METHODS

Total polysaccharides (TPL) were applied to ion exchange chromatography and eluted stepwise. Paw edema was induced s.c. by λ-carrageenan, dextran, histamine, serotonin, compound 48/80, bradykinin, prostaglandin E(2) (PGE(2)) or L-arginine and analyzed by plethysmometry and protein leakage by spectrophotometry. Peritonitis was induced i.p. by carrageenan or N-formyl-methionyl-leucyl-phenylalanine (fMLP) and analyzed 4 h later for leukocyte migration and protein leakage. Animals were treated i.v. with TPL or polysaccharide fractions (0.01, 0.1, 1 mg/kg) 30 min before stimuli in both models. Toxicity (variation of body/organ mass and hematological/biochemical parameters) was evaluated after the seven-day treatment with the most active polysaccharide fraction (1 mg/kg; i.v.).

RESULTS

Chromatography of TPL (2.8% yield) provided three major polysaccharide fractions (FI, FII, FIII). At 1 mg/kg, TPL inhibited the paw edema induced by carrageenan (60%) and FIII (fraction presenting high carbohydrate and low protein content) inhibited the inflammatory parameters in the paw edema induced by the following stimuli: carrageenan (70%), dextran (53%), histamine (65%), serotonin (62%), bradykinin (60%), PGE(2) (63%), nitric oxide (61%) and compound 48/80 (36%). Additionally, FIII at 1 mg/kg inhibited the carrageenan-induced edema in animals with intact mast cells, but only the late phase of those with degranulated mast cells elicited by compound 48/80. Moreover, FIII inhibited cell migration and protein leakage in the model of peritonitis elicited by carrageenan (88%) and fMLP (64%), being well tolerated by animals.

CONCLUSIONS

Extracts and polysaccharide fractions of Caesalpinia ferrea pods exhibit potent anti-inflammatory activity via negative modulation of histamine, serotonin, bradykinin, PGE(2) and NO released in the carrageenan-induced edema, showing involvement of mast cells. FIII could be interfering not only in the vascular, but also in cellular inflammatory events, revealing to be an important active component of traditionally prepared remedies used to treat inflammatory states.