Polygonum viviparum L. inhibits the lipopolysaccharide‐induced inflammatory response in RAW264.7 macrophages through haem oxygenase‐1 induction and activation of the Nrf2 pathway

BACKGROUND: Polygonum viviparum L. (PV) is a member of the family Polygonaceae and is widely distributed in high‐elevation areas. It is used as a folk remedy to treat inflammation‐related diseases. This study was focused on the anti‐inflammatory response of PV against lipopolysaccharide (LPS)‐induced inflammation in RAW264.7 macrophages. RESULTS: Treatment with PV did not cause cytotoxicity at 0–50 µg mL^?1 in RAW264.7 macrophages, and the IC₅₀ value was 270 µg mL^?1. PV inhibited LPS‐stimulated nitric oxide (NO), prostaglandin (PG)E₂, interleukin (IL)‐1β and tumour necrosis factor (TNF)‐α release and inducible NO synthase (iNOS) and cyclooxygenase (COX)‐2 protein expression. In addition, PV suppressed the LPS‐induced p65 expression of nuclear factor (NF)‐κB, which is associated with the inhibition of IκB‐α degradation. These results suggest that, among mechanisms of the anti‐inflammatory response, PV inhibits the production of NO and these cytokines by down‐regulating iNOS and COX‐2 gene expression. Furthermore, PV can induce haem oxygenase (HO)‐1 protein expression through nuclear factor E2‐related factor 2 (Nrf2) activation. A specific inhibitor of HO‐1, zinc(II) protoporphyrin IX, inhibited the suppression of iNOS and COX‐2 expression by PV. CONCLUSION: These results suggest that PV possesses anti‐inflammatory actions in macrophages and works through a novel mechanism involving Nrf2 actions and HO‐1. Thus PV could be considered for application as a potential therapeutic approach for inflammation‐associated disorders. © 2012 Society of Chemical Industry     

Quercetin‐induced apoptotic cascade in cancer cells: Antioxidant versus estrogen receptor α‐dependent mechanisms

The flavonol quercetin, especially abundant in apple, wine, and onions, is reported to have anti‐proliferative effects in many cancer cell lines. Antioxidant or pro‐oxidant activities and kinase inhibition have been proposed as molecular mechanisms for these effects. In addition, an estrogenic activity has been observed but, at the present, it is poorly understood whether this latter activity plays a role in the quercetin‐induced anti‐proliferative effects. Here, we studied the molecular mechanisms of quercetin committed to the generation of an apoptotic cascade in cancer cells devoid or containing transfected estrogen receptor α (ERα; i.e., human cervix epitheloid carcinoma HeLa cells). Although none of tested quercetin concentrations increase reactive oxygen species (ROS) generation in HeLa cells, quercetin stimulation prevents the H₂O₂‐induced ROS production both in the presence and in the absence of ERα. However, this flavonoid induces the activation of p38/MAPK, leading to the pro‐apoptotic caspase‐3 activation and to the poly(ADP‐ribose) polymerase cleavage only in the presence of ERα. Notably, no down‐regulation of survival kinases (i.e., AKT and ERK) was reported. Taken together, these findings suggest that quercetin results in HeLa cell death through an ERα‐dependent mechanism involving caspase‐ and p38 kinase activation. These findings indicate new potential chemopreventive actions of flavonoids on cancer growth.     

Cranberry extract and quercetin modulate the expression of cyclooxygenase‐2 (COX‐2) and IκBα in human colon cancer cells

BACKGROUND: Cranberry (Vaccinium marcocarpon) fruit and quercetin, a major flavonoid found in cranberries, are likely contributors to chemoprevention, and their anti‐inflammatory activities may play a potential role in colon cancer prevention. The aim of this study was to examine the effect of cranberry extract and quercetin on basal expression of cyclooxygenase‐2 (COX‐2) and IκBα as well as the effect on phorbol 12‐myristate 13‐acetate (PMA)‐induced COX‐2 expression in colon cancer cells. RESULTS: HT‐29 human colon adenocarcinoma cells were treated with various concentrations of cranberry extract or quercetin and/or PMA, and the protein expression of COX‐2 and IκBα was determined. The results indicated that cranberry extract and quercetin decreased COX‐2 expression and suppressed degradation of IκBα in unstimulated cells. In PMA‐stimulated cells, cranberry extract was also able to decrease COX‐2 expression and suppress degradation of IκBα. CONCLUSION: The results suggest that a possible mechanism involved in the anti‐cancer activity of cranberry and quercetin is partly mediated through its anti‐inflammatory action. These findings indicate that cranberry and quercetin may reduce the risk of colon cancer possibly by suppressing inflammatory responses. Copyright © 2008 Society of Chemical Industry     

Anti‐inflammatory and anticancer activities of water‐soluble peptide extracts of buffalo and cow milk Cheddar cheeses

This article aimed to assess the anti‐inflammatory and anticancer potential of water‐soluble peptide (WSP) extracts from buffalo and cow milk Cheddar cheeses. Anti‐inflammatory activity was evaluated on the basis of nitric oxide (NO) production in lipopolysaccharide‐stimulated macrophage (RAW‐264.7) cells. A cell viability assay, cell cycle arrest and apoptosis were performed to explore anticancer activity in a colon cancer model (HT‐29). The WSP extracts of both Cheddar cheeses effectively inhibited NO production in activated macrophages. Maximum growth inhibition was observed in the HT‐29 cells at concentrations of 400 and 500 μg/mL. A significant increase in cell population at G₀/G₁ phase of the cell cycle was observed. Moreover, the WSP extracts also induced extensive apoptosis in colon cancer cells.     

Dietary grape seed extract ameliorates symptoms of inflammatory bowel disease in IL10‐deficient mice

Grape seed extract (GSE) is a by‐product of the wine industry, with abundant polyphenolic compounds known for their anti‐inflammatory and anti‐oxidative effects. Using IL10‐deficient mice (IL10KO), here we showed that GSE (1% of dry feed weight) ameliorated inflammatory bowel disease indices, increased colonic goblet cell numbers and decreased myeloperoxidase levels in the large intestine. Concomitantly, GSE supplementation attenuated inflammation, decreased the expression of pore forming tight junction protein claudin2, and increased levels of Lactobacilli and Bacteroides in the gut microbiota of IL10KO mice. In summary, our study shows that GSE has protective roles on inflammatory bowel disease through altering gut inflammation, tight junction protein expression, and gut microbiota composition.     

Impact of a probiotic Enterococcus faecalis in a gnotobiotic mouse model of experimental colitis

Scope : IL‐10‐deficient (IL‐10^?/?) mice are susceptible to the development of chronic intestinal inflammation in response to the colonization with commensal Enterococcus faecalis isolates. The aim of this study was to characterize the impact of a probiotic E. faecalis strain in germ‐free, wild‐type (WT), and disease‐susceptible IL‐10^?/? mice. Methods and results : The probiotic E. faecalis and the colitogenic control strain OG1RF induced IL‐6 and IFN‐γ inducible protein‐10 secretion in the murine intestinal epithelial cell line Mode K. Epithelial cell activation involved nuclear factor κ B, p38 and extracellular signal‐regulated kinase 1/2‐dependent pathways. Mouse embryonic fibroblasts from WT and toll‐like receptor‐2‐deficient (TLR‐2^?/?) mice confirmed that both E. faecalis strains trigger pro‐inflammatory responses via the pattern recognition receptor TLR‐2. Monoassociation of germ‐free IL‐10^?/? mice with the probiotic E. faecalis strain revealed pro‐inflammatory epithelial cell activation and colonic tissue pathology. The non‐pathogenic nature of E. faecalis was confirmed in monoassociated WT mice. 2‐DE and MALDI‐TOF MS identified the ER stress chaperone Hspa5 (glucose‐regulated protein 78) and 3‐mercaptopyruvate sulfurtransferase as key targets in the epithelium from IL‐10^?/? and TLR‐2^?/? mice. Conclusion : This study shows the potential of probiotic bacteria to initiate pro‐inflammatory responses in the disease‐susceptible but not the normal host.     

Suppressive effects of extracts from the aerial part of Coriandrum sativum L. on LPS‐induced inflammatory responses in murine RAW 264.7 macrophages

BACKGROUND: Coriandrum sativum is used not only as a spice to aid flavour and taste values in food, but also as a folk medicine in many countries. Since little is known about the anti‐inflammatory ability of the aerial parts (stem and leaf) of C. sativum, the present study investigated the effect of aerial parts of C. sativum on lipopolysaccharide (LPS)‐stimulated RAW 264.7 macrophages. We further explored the molecular mechanism underlying these pharmacological properties of C. sativum. RESULTS: Ethanolic extracts from both stem and leaf of C. sativum (CSEE) significantly decreased LPS‐induced nitric oxide and prostaglandin E₂ production as well as inducible nitric oxide synthase, cyclooxygenase‐2, and pro‐interleukin‐1β expression. Moreover, LPS‐induced IκB‐α phosphorylation and nuclear p65 protein expression as well as nuclear factor‐κB (NF‐κB) nuclear protein–DNA binding affinity and reporter gene activity were dramatically inhibited by aerial parts of CSEE. Exogenous addition of CSEE stem and leaf significantly reduced LPS‐induced expression of phosphorylated mitogen‐activated protein kinases (MAPKs). CONCLUSION: Our data demonstrated that aerial parts of CSEE have a strong anti‐inflammatory property which inhibits pro‐inflammatory mediator expression by suppressing NF‐κB activation and MAPK signal transduction pathway in LPS‐induced macrophages. Copyright © 2010 Society of Chemical Industry     

Production of hydrogen peroxide is responsible for the induction of apoptosis by hydroxytyrosol on HL60 cells

Hydroxytyrosol [3,4‐dihydroxyphenylethanol (3,4‐DHPEA)], a phenolic compound found exclusively in olive oil, exerts growth‐suppressive and pro‐apoptotic effects on different cancer cells. Although some molecular mechanisms involved in the pro‐apoptotic activity of 3,4‐DHPEA have been proposed, the initial stress signals responsible of this phenomenon are not known. Our aim was to assess the involvement of reactive oxygen species as mediators of apoptosis induced by 3,4‐DHPEA on HL60 cells. Apoptosis was determined by analyzing the nuclear fragmentation by both fluorescence microscopy and flow cytometry. The externalization of phosphatidylserine was evidenced using an Annexin V‐FITC kit. The concentration of H₂O₂ in the culture medium was measured by the ferrous ion oxidation‐xylenol orange method. The pro‐apoptotic effect of 3,4‐DHPEA (100 μM) was prevented by N‐acetyl‐cysteine, ascorbate, and α‐tocopherol. Catalase suppressed the 3,4‐DHPEA‐induced apoptosis, while the Fe(II)‐chelating reagent o‐phenantroline showed no effect, suggesting the involvement of H₂O₂ but not of OH^?. Indeed, 3,4‐DHPEA caused accumulation of H₂O₂ in the culture medium. Tyrosol (p‐hydroxyphenylethanol) and caffeic acid, compounds structurally similar to 3,4‐DHPEA but not able to generate H₂O₂, did not induce an appreciable apoptotic effect. This is the first study demonstrating that apoptosis induction by 3,4‐DHPEA is mediated by the extracellular production of H₂O₂.     

Anti-inflammatory activities of aqueous extract of Mesona procumbens in experimental mice

BACKGROUND: Mesona procumbens is consumed as a herbal drink and jelly‐type dessert in Taiwan. The aim of this study was to determine the mechanism of anti‐inflammatory activities of the aqueous extract of M. procumbens (AMP) using the λ‐carrageenin (Carr)‐induced mouse paw oedema model. The fingerprint chromatogram of AMP was obtained by high‐performance liquid chromatography (HPLC) analysis. To investigate the anti‐inflammatory mechanism of AMP, the activities of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) and the level of malondialdehyde (MDA) in paw oedema were monitored. Serum nitric oxide (NO), tumour necrosis factor‐α (TNF‐α) and interleukin‐1β (IL‐1β) were also evaluated. RESULTS: The fingerprint chromatogram from HPLC indicated that AMP contained protocatechuic acid, chlorogenic acid, vanillic acid and caffeic acid. In the anti‐inflammatory test, AMP decreased paw oedema after Carr administration and increased the CAT, SOD and GPx activities and decreased the MDA level in paw oedema at 5 h after Carr injection. AMP also affected the serum NO, TNF‐α and IL‐1β levels at 5 h after Carr injection. Western blotting revealed that AMP decreased the expression of Carr‐induced inducible nitric oxide synthase (iNOS) and cyclooxygenase‐2 (COX‐2). CONCLUSION: Mesona procumbens has the potential to provide a therapeutic approach to inflammation‐associated disorders. Copyright © 2011 Society of Chemical Industry     

Bax induces activation of the unfolded protein response by inducing HAC1 mRNA splicing in Saccharomyces cerevisiae

Bax, a multidomain pro‐apoptotic Bcl‐2 protein, localizes to the endoplasmic reticulum (ER), where it regulates ER stress‐induced apoptosis. Adaptation to ER stress depends on the activation of an integrated signal transduction pathway known as the unfolded protein response (UPR). This study examined the death‐inducing activity of Bax and its ability to induce UPR signalling pathways in yeast. We observed that inhibition of global translation in yeast cells expressing Bax correlated with Bax‐induced cell death. Using a lacZ reporter containing several UPR cis‐activating regulatory elements, we also found that Bax directly activated the UPR. Furthermore, this correlated with the splicing of HAC1 mRNA, a gene involved in UPR activation. Bax induced expression of representative UPR target genes such as KAR2, DER1 and GCN4. Finally, we found that Ire1p function is critical for Bax‐induced cell death. Copyright © 2012 John Wiley & Sons, Ltd.     

The preventive role of breadfruit against inflammation‐associated epithelial carcinogenesis in mice

Artocarpus communis has been identified as a rich source of flavonoids and has been gaining attention for its potential chemopreventive abilities. In this study, methanol extracts from the fruit of A. communis (MEFA) and leaf of A. communis (MELA) were prepared, and their effects on inflammation‐associated skin tumorigenesis were assessed using mouse models, including 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) induced cutaneous inflammation as well as 7,12‐dimethylbenz[α]anthracene (DMBA) initiated and TPA‐promoted skin tumorigenesis. According to the results, both MEFA and MELA decreased the intensity of leukocyte infiltration in mouse dorsal skin and cutaneous edema induced by TPA, which appeared to be mediated by inhibition of proinflammatory genes (inducible nitric oxide synthase, cyclooxygenase‐2 (COX‐2), tumor necrosis factor‐α (TNF‐α), IL‐1β, and IL‐6) and proinflammatory mediators (TNF‐α, IL‐1β, and Prostaglandin E₂). In addition, topical application with MEFA or MELA effectively attenuated tumor incidence, multiplicity, volume, malignancy as well as angiogenesis of TPA‐stimulated skin tumor promotion in DMBA‐initiated mice. Notably, immunohistochemical stain showed that MEFA and MELA attenuated COX‐2 expression of both skin and tumor tissues in different animal tests, which may be closely related to the suppression of nuclear factor kappa B/activator protein signaling networks. These findings first demonstrate that flavonoid‐rich A. communis may exert potent anti‐inflammatory activity through modulation of COX‐2 in TPA‐activated skin and tumor tissues.     

Marie Ménard apples with high polyphenol content and a low‐fat diet reduce 1,2‐dimethylhydrazine‐induced colon carcinogenesis in rats: Effects on inflammation and apoptosis

Inflammation may increase cancer risk, therefore, we studied whether polyphenol‐rich Marie Ménard (MM) apples with reported anti‐inflammatory activity prevent 1,2‐dimethylhydrazine (DMH)‐induced colon carcinogenesis in rats and, likewise whether high‐fat (HF) diet promoting carcinogenesis, may affect inflammation. DMH‐induced rats were fed for 15 weeks with: an HF diet (23% corn oil w/w); an HF diet containing 7.6% w/w lyophilized MM (apple diet (AD)); a low‐fat (LF) diet and an HF diet containing piroxicam (PXC) (0.01% w/w) as control. Mucin depleted foci (MDF), precancerous lesions in the colon, were dramatically reduced in the AD, LF, and PXC groups compared with the HF. Peritoneal macrophage activation, an index of systemic inflammation, was significantly decreased in the AD, LF, and PXC groups. TNF‐α, iNOS, IL‐1β, IL‐6 m‐RNA expression in the colon, as well as CD68 cells and plasmatic PGE2 were lower in the AD, but not in the LF group. Apoptosis in the MDF of both the AD and LF‐fed rats was significantly higher than in HF rats. In conclusion, AD has a strong chemopreventive effect, reducing inflammation, and increasing apoptosis, while the chemopreventive effect of the LF diet seems mediated mainly by increased apoptosis in MDF.     

Bioactivity of extracts from gonadal tissue of the edible Australian purple sea urchin Heliocidaris erythrogramma

Dichloromethane (DCM), methanol (MeOH) and aqueous extracts of male gonadal tissue from Heliocidaris erythrogramma were screened for bioactivity. None of the extracts were antibacterial against Gram‐positive Staphylococcus aureus and Gram‐negative Escherichia coli. The aqueous extract scavenged the reactive oxygen species (ROS), hydrogen peroxide (H₂O₂), but did not react with the hydroxyl radical (OH·) or with the stable free radical 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH·). No antioxidant potential was evident for the DCM and MeOH extracts. The extracts displayed various levels of anti‐inflammatory action in connection with inhibition of cyclooxygenase (ovine COX‐1 and COX‐2), but were insignificant inhibitors of lipoxygenase (soybean 15‐LO) pure enzyme. Anti‐inflammatory action related to reduction of leukotriene production by stimulated porcine neutrophils was affected only by the aqueous extract. The DCM and aqueous extracts, but not the MeOH extract, showed anti‐inflammatory activity in rats developing adjuvant‐induced polyarthritis. Overall, the DCM extract was 75% inhibitory of arthritis symptoms, and the aqueous extract was 55% inhibitory. Suppression of growth of the mouse leukaemic lymphoblastic (P388) cell line was evident for the DCM extract only. This extract was also able to exert a cytotoxic effect on the tumour cell line. For all extracts, no general cytotoxicity against isolated rat hepatocytes was observed. Copyright © 2007 Society of Chemical Industry     

Protective effect of dried safflower petal aqueous extract and its main constituent,carthamus yellow,against lipopolysaccharide‐induced inflammation in RAW264.7 macrophages

BACKGROUND: Safflower, whose botanic name is Carthamus tinctorius L., is a member of the family Compositae or Asteraceae. Carthamus yellow (CY) is the main constituent of safflower and is composed of safflomin A and safflomin B. Dried safflower petals are used in folk medicine and have been shown to invigorate blood circulation, break up blood stasis, and promote menstruation. In addition, dried safflower petals contain yellow dyes that are used to color food and cosmetics. In this study, we investigated the effects of dried safflower petals aqueous extracts (SFA) and CY on lipopolysaccharide (LPS)‐induced inflammation using RAW264.7 macrophages. RESULTS: Our data showed that treatment with SFA (1–1000 µg mL^?1) and CY (1–2000 µg mL^?1) does not cause cytotoxicity in cells. SFA and CY inhibited LPS‐stimulated nitric oxide (NO), prostaglandin E₂ (PGE₂), and interleukin 1β (IL‐1β) release, through attenuation of inducible nitric oxide synthase (iNOS) and cyclooxygenase‐2 (COX‐2) protein expression. Further, SFA and CY suppressed the LPS‐induced phosphorylation of nuclear factor‐κB, which was associated with the inhibition of IκB‐α degradation. CONCLUSION: These results suggest that SFA and CY provide an anti‐inflammatory response through inhibiting the production of NO and PGE₂ by the downregulation of iNOS and COX‐2 gene expression. Thus safflower petals have the potential to provide a therapeutic approach to inflammation‐associated disorders. Copyright © 2010 Society of Chemical Industry     

Anti‐inflammatory activity of rosemary extracts obtained by supercritical carbon dioxide enriched in carnosic acid and carnosol

The in vitro anti‐inflammatory activity of supercritical rosemary (Rosmarinus officinalis L.) extracts (rosemary A and B) is been reported in this study. To achieve that, THP‐1 macrophages were activated using lipopolysaccharide or human ox‐LDL and secretion and gene expression of TNF‐α, IL‐1β, IL‐6 and IL‐10 were evaluated, as well as COX‐2 gene expression. Results indicated that both rosemary extracts (A & B) exhibit high anti‐inflammatory activity although at a higher extent in case of rosemary B extract (5 μg mL^?1), representing a higher quantity of carnosic acid and carnosol than rosemary A. When comparing the activity of the extract to the standard itself, the anti‐inflammatory activity of standards of carnosic acid and carnosol was not as intense as that obtained with rosemary B. These data indicated that although carnosic acid content in the extracts is considered as the main anti‐inflammatory compound, a synergistic interaction with other compounds may play a significant role in enhancing its activity. Results provided the grounds for possible increase in the application of supercritical rosemary extracts in food formulations for mitigation or prevention of inflammatory diseases.     

Sarcodon aspratus Extract Ameliorates Dextran Sulfate Sodium‐Induced Colitis in Mouse Colon and Mesenteric Lymph Nodes

Mushrooms have been previously investigated for their immune‐modulating and anti‐inflammatory properties. We examined whether the anti‐inflammatory properties of Sarcodon aspratus ethanol extract (SAE) could elicit protective effects against dextran sulfate sodium (DSS)‐induced colitis in vivo. Male C57/BL6 mice were randomly assigned to 1 of 4 treatment groups: control (CON; n = 8), DSS‐treated (DSS; n = 9), DSS+SAE at 50 mg/kg BW (SAE50; n = 8), and DSS+SAE at 200 mg/kg BW groups (SAE200; n = 9). DSS treatment induced significant weight loss, which was significantly recovered by SAE200. Although SAE did not affect DSS‐mediated reductions in colon length, it improved diarrhea and rectal bleeding induced by DSS. SAE at 200 mg/kg BW significantly attenuated IL‐6 and enhanced IL‐10 expression in mesenteric lymph nodes (MLN), and significantly reduced IL‐6 levels in splenocytes. SAE200 also significantly attenuated DSS‐induced increase in IL‐6 and IL‐1β, and reductions in IL‐10 in colon tissue. High levels of SAE were also observed to significantly decrease inflammatory COX‐2 expression that was upregulated by DSS in mice colon. These findings may have relevance for novel therapeutic strategies to mitigate inflammatory bowel disease‐relevant inflammatory responses, via the direct and indirect anti‐inflammatory activity of SAE. We also found that SAE harbors significant quantities of total fiber and β‐glucan, suggesting a possible role for these components in protection against DSS‐mediated colitis.