Malabaricone C suppresses lipopolysaccharide-induced inflammatory responses via inhibiting ROS-mediated Akt/IKK/NF-κB signaling in murine macrophages

Naturally Derived Malabaricone B as a Promising Bactericidal Candidate Targeting Multidrug-Resistant Staphylococcus aureus also Possess Synergistic Interactions with Clinical Antibiotics

The emergence of multidrug-resistant (MDR) superbugs underlines the urgent need for innovative treatment options to tackle resistant bacterial infections. The clinical efficacy of natural products directed our efforts towards developing new antibacterial leads from naturally abundant known chemical structures. The present study aimed to explore an unusual class of phenylacylphenols (malabaricones) from Myristicamalabarica as antibacterial agents. In vitro antibacterial activity was determined via broth microdilution, cell viability, time-kill kinetics, biofilm eradication, intracellular killing, and checkerboard assays. The efficacy was evaluated in vivo in murine neutropenic thigh and skin infection models. Confocal and SEM analyses were used for mechanistic studies. Among the tested isolates, malabaricone B (NS-7) demonstrated the best activity against S. aureus with a favorable selectivity index and concentration-dependent, rapid bactericidal killing kinetics. It displayed equal efficacy against MDR clinical isolates of S. aureus and Enterococci, efficiently clearing S. aureus in intracellular and biofilm tests, with no detectable resistance. In addition, NS-7 synergized with daptomycin and gentamicin. In vivo, NS-7 exhibited significant efficacy against S. aureus infection. Mechanistically, NS-7 damaged S. aureus membrane integrity, resulting in the release of extracellular ATP. The results indicated that NS-7 can act as a naturally derived bactericidal drug lead for anti-staphylococcal therapy.

Mitochondrial Methionyl-tRNA Formyltransferase Deficiency Alleviates Metaflammation by Modulating Mitochondrial Activity in Mice

Various studies have revealed the association of metabolic diseases with inflammation. Mitochondria are key organelles involved in metabolic regulation and important drivers of inflammation. However, it is uncertain whether the inhibition of mitochondrial protein translation results in the development of metabolic diseases, such that the metabolic benefits related to the inhibition of mitochondrial activity remain unclear. Mitochondrial methionyl-tRNA formyltransferase (Mtfmt) functions in the early stages of mitochondrial translation. In this study, we reveal that feeding with a high-fat diet led to the upregulation of Mtfmt in the livers of mice and that a negative correlation existed between hepatic Mtfmt gene expression and fasting blood glucose levels. A knockout mouse model of Mtfmt was generated to explore its possible role in metabolic diseases and its underlying molecular mechanisms. Homozygous knockout mice experienced embryonic lethality, but heterozygous knockout mice showed a global reduction in Mtfmt expression and activity. Moreover, heterozygous mice showed increased glucose tolerance and reduced inflammation, which effects were induced by the high-fat diet. The cellular assays showed that Mtfmt deficiency reduced mitochondrial activity and the production of mitochondrial reactive oxygen species and blunted nuclear factor-κB activation, which, in turn, downregulated inflammation in macrophages. The results of this study indicate that targeting Mtfmt-mediated mitochondrial protein translation to regulate inflammation might provide a potential therapeutic strategy for metabolic diseases.

Malabaricone C, a constituent of spice Myristica malabarica, exhibits anti-inflammatory effects via modulation of cellular redox

The present study primarily focuses on the efficacy of Malabaricone C (Mal C) as an anti-inflammatory agent. Mal C inhibited mitogen-induced T-cell proliferation and cytokine secretion. Mal C significantly reduced cellular thiols in lymphocytes. N-acetyl cysteine (NAC) restored cellular thiol levels and abrogated Mal C-mediated inhibition of T-cell proliferation and cytokine secretion. Physical interaction between Mal C and NAC was evinced from HPLC and spectral analysis. Mal C treatment significantly inhibited concanavalin A-induced phosphorylation of ERK/JNK and DNA binding of NF-κB. Administration of Mal C to mice suppressed T-cell proliferation and effector functions ex vivo. Mal C treatment did not alter the homeostatic proliferation of T-cells in vivo but completely abrogated acute graft-versus-host disease (GvHD)-associated morbidity and mortality. Our studies indicate probable use of Mal C for prophylaxis and treatment of immunological disorders caused due to hyper-activation of T-cells.

Multifunctional injectable hydrogel for effective promotion of cartilage regeneration and protection against osteoarthritis: combined chondroinductive, antioxidative and anti-inflammatory strategy

The regeneration of the articular cartilage defects is characterized by the improvement in the quality of the repaired tissue and the reduction in the potential development of perifocal osteoarthritis (OA). Usually, the injection of dexamethasone (Dex) in the OA joints slows down the progression of inflammation and relieves pain. However, the anti-inflammatory Dex injected in the joint cavity is rapidly cleared, leading to a poor therapeutic effect. Multifunctional hydrogels with simultaneous chondrogenic differentiation, antioxidative, and anti-inflammatory capacities may represent a promising solution. Therefore, in this work, a novel injectable hydrogel based on double cross-linking of Schiff base bonds and coordination of catechol-Fe was developed. The obtained hydrogel (Gel-DA/DOHA/DMON@Dex@Fe) possessed molding performance in situ, excellent mechanical strength, controllable biodegradability, the on-demand release of the drug, and biocompatibility. The hydrogel system stimulated the HIF-1α signaling pathway and suppressed inflammation thanks to the introduction of DMON@Fe, consequently facilitating chondrogenic differentiation. The synergistic anti-inflammatory effect together with the induction of chondrogenesis by Dex-loaded Gel-DA/DOHA/DMON@Fe hydrogel allowed the promotion of cartilage repair, as demonstrated by in vivo experiments. Hence, the proposed multifunctional scaffold provides a promising advancement in articular cartilage tissue engineering and may have great prospects in the prevention of OA.

Malabaricone C Attenuates Nonsteroidal Anti-Inflammatory Drug-Induced Gastric Ulceration by Decreasing Oxidative/Nitrative Stress and Inflammation and Promoting Angiogenic Autohealing

Aims: Nonsteroidal anti-inflammatory drugs (NSAIDs), among the most commonly used drugs worldwide, are associated with gastrointestinal (GI) complications that severely limit the clinical utility of this essential class of pain medications. Here, we mechanistically dissect the protective impact of a natural product, malabaricone C (Mal C), on NSAID-induced gastropathy. Results: Mal C dose dependently diminished erosion of the stomach lining and inflammation in mice treated with NSAIDs with the protective impact translating to improvement in survival. By decreasing oxidative and nitrative stress, Mal C treatment prevented NSAID-induced mitochondrial dysfunction and cell death; nuclear factor κ-light-chain enhancer of activated B cell induction, release of proinflammatory cytokines and neutrophil infiltration; and disruptions in the vascular endothelial growth factor/endostatin balance that contributes to mucosal autohealing. Importantly, Mal C failed to impact the therapeutic anti-inflammatory properties of multiple NSAIDs in a model of acute inflammation. In all assays tested, Mal C proved as or more efficacious than the current first-line therapy for NSAID-dependent GI complications, the proton pump inhibitor omeprazole. Innovation: Given that omeprazole-mediated prophylaxis is, itself, associated with a shift in NSAID-driven GI complications from the upper GI to the lower GI system, there is a clear and present need for novel therapeutics aimed at ameliorating NSAID-induced gastropathy. Mal C provided significant protection against NSAID-induced gastric ulcerations impacting multiple critical signaling cascades contributing to inflammation, cell loss, extracellular matrix degradation, and angiogenic autohealing. Conclusion: Thus, Mal C represents a viable lead compound for the development of novel gastroprotective agents.

Phenolic compounds from nutmeg (Myristica fragrans Houtt.) inhibit the endocannabinoid-modulating enzyme fatty acid amide hydrolase

OBJECTIVES

The study aimed to identify nutmeg compounds that indirectly interact with the endocannabinoid system through inhibition of the fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) enzymes.

METHODS

Thirteen compounds were screened for FAAH and MAGL inhibition. Compounds demonstrating significant FAAH inhibition were evaluated to determine the halfmaximal inhibitory concentration (IC₅₀ ). The most potent compound was investigated in the elevated plus maze (EPM) rodent anxiety model.

KEY FINDINGS

Three compounds, licarin A (9), 5'-methoxylicarin A (8) and malabaricone C (6) were most active in inhibiting FAAH with IC₅₀ of 7.02 μm ± 2.02, 4.57 μm ± 0.66 and 38.29 μm ± 6.18, respectively. None of the purified compounds showed significant MAGL inhibition. Because of its relative high potency and selectivity, compound 8 was further evaluated in the EPM animal model of anxiety. The compound showed significant increase in number of open arm entries (P < 0.05) when administered at 120 mg/kg dose. No effect was observed on the locomotor activity.

CONCLUSIONS

Results collected introduce active nutmeg compounds as potential leads for further development. Of the three compounds, 8 possesses highest potency and FAAH selectivity as well as anxiolytic activity. Furthermore, in vivo testing in appropriate behavioural animal paradigms is warranted.

Combination of quercetin and cisplatin enhances apoptosis in OSCC cells by downregulating xIAP through the NF-κB pathway

While cisplatin is a first-line chemotherapeutic drug commonly used to treat patients with oral squamous cell carcinoma (OSCC), the cisplatin-resistance poses a major challenge for its clinical application. Recent studies have shown that quercetin, a natural flavonoid found in various plants and foods possesses an anti-cancer effect. The following study examined the combined effect of quercetin and cisplatin on OSCC apoptosis in vitro and in vivo (using a mice tumor model). We found that quercetin promotes cisplatin-induced apoptosis in human OSCC (cell lines Tca-8113 and SCC-15) by down-regulating NF-κB. Pretreatment of cancer cells with quercetin inhibited the phosphorylation Akt and IKKβ, and led to the suppression of NF-κB and anti-apoptotic protein xIAP. In addition, we observed that the pretreatment of cancer cells with quercetin improves extrinsic and intrinsic apoptosis by activating caspase-8 and caspase-9, respectively. Our in vivo data also indicated that the combination of quercetin and cisplatin may inhibit the xenograft growth in mice. To sum up, our results provide a new evidence for the application of quercetin and cisplatin in OSCC therapy.

Olive oil polyphenols extracts inhibit inflammatory markers in J774A.1 murine macrophages and scavenge free radicals

Here we evaluate the olive oil antiradical and anti-inflammatory potential through its polyphenols extracts and examine the influence of olive maturity on olive oil quality properties, polyphenols composition and biological potentials. Samples have been obtained from minor Tunisian olive cultivars (Chemchali, Fouji and Zarrazi) at different maturity indices. Principal quality properties were evaluated and polyphenols analysis was carried out by Folin Ciocalteu reagent and HPLC-UV-MS. Antiradical activity was examined by DPPH and FRAP scavenging assays while J774A.1 murine macrophages were used to evaluate anti-inflammatory potential by analyzing NO production with Griess reagent method and iNOS and COX-2 expression by cytofluorimetric analysis. Our results revealed that quality characteristics, total phenol content, as well as phenolic compound concentrations were significantly affected by the olive maturity levels. On the other hand, the polyphenols extracts showed an interesting radical scavenging capacity and a potential ability to inhibit inflammatory markers at 90% for NO release and 75% for iNOS expression. Thus, our study establishes that olive oil through its polyphenols extracts has a substantial antiradical and anti-inflammatory potential. Likewise a lot of attention should be attributed to olive ripening level in order to decide the optimum harvesting time.

Measurement of NF-κB Activation in TLR-Activated Macrophages

Nuclear factor kappa-B (NF-κB) is a key transcription factor in the regulation of the innate immune inflammatory response in activated macrophages. NF-κB functions as a homo- or hetero-dimer derived from one or more of the five members of the NF-κB family, and is activated through a well-studied process of stimulus-dependent inhibitor degradation, post-translational modification, nuclear translocation, and chromatin binding. Its activity is subject to multiple levels of feedback control through both inhibitor protein activity and direct regulation of NF-κB components. Many methods have been developed to measure and quantify NF-κB activation. In this chapter, we summarize available methods and present a protocol for image-based measurement of NF-κB activation in macrophages activated with microbial stimuli. Using either a stably expressed GFP-tagged fusion of the RelA NF-κB protein, or direct detection of endogenous RelA by immunocytochemistry, we describe data collection and analysis to quantify NF-κB cytosol to nuclear translocation in single cells using fluorescence microscopy.

Dihydrofisetin exerts its anti-inflammatory effects associated with suppressing ERK/p38 MAPK and Heme Oxygenase-1 activation in lipopolysaccharide-stimulated RAW 264.7 macrophages and carrageenan-induced mice paw edema

Dihydrofisetin is a flavanonol derived from some edible wild herbs and traditional Chinese medicines. It has been found to possess many biological activities. However, the anti-inflammatory potential of Dihydrofisetin remains uncharacterized. The aim of the present study was to investigate the anti-inflammatory activity of Dihydrofisetin and its underlying mechanisms. We found that Dihydrofisetin dose-dependently inhibited lipopolysaccharide-induced productions of nitric oxide (NO) and prostaglandin E₂ (PGE₂) in RAW 264.7 macrophages, probably through suppressing the protein expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). The expressions of pro-inflammatory cytokines, such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6) and monocyte chemotactic protein (MCP-1) were also suppressed. We further demonstrated that Dihydrofisetin inhibited the activation of mitogen-activated protein kinases (MAPKs) pathway and phosphorylation of IκB-α whereas upregulated the expression of heme oxygenase-1 (HO-1). The in vivo carrageenan-induced mice paw edema study also indicated that treatment with 100 mg/kg of Dihydrofisetin could significantly inhibit carrageenan induced paw edema, decrease the levels of TNF-α, IL-6 and MDA, and increase the activity of GSH-Px in paw tissues. Taken together, Dihydrofisetin may act as a natural agent for treating inflammatory diseases by targeting MAPK, NF-κB and HO-1 pathways.

Total Syntheses of Malabaricones B and C via a Cross-Metathesis Strategy

The malabaricones A-D belong to the class of diarylnonanoids isolated from the Myristicaceae family of plants. Although malabaricone C displayed various interesting biological activities, its isolation remains tedious due to its close chemical similarity to malabaricones A, B, and D. Therefore, development of an efficient synthesis route has become essential to cater to the need of large amounts of malabaricone C for its pharmacological profiling. So far there is only one report of the synthesis of malabaricone C through a lengthy sequence of reactions. We have developed an efficient and short route for the syntheses of malabaricones B and C, which will also provide a convenient access to all other members of the malabaricone family. Synthesis of an important building block, ω-aryl heptyl bromide, employed in the synthesis was realized by adopting a cross-metathesis reaction as the key step.

Glutamine decreases intestinal mucosal injury in a rat model of intestinal ischemia-reperfusion by downregulating HMGB1 and inflammatory cytokine expression

Intestinal ischemia-reperfusion (IR) is a common clinical pathophysiological process that is common in severe trauma, major surgery, and in post-resuscitation. Glutamine (Gln) reduces intestinal IR injury, however, its mechanism of action remains to be determined. High mobility group box 1 (HMGB1) protein, nuclear factor-κB (NF-κB), tumor necrosis factor-α (TNF-α), and interleukin-1 (IL-1) are mediators involved in the pathophysiology of intestinal IR injury. The aim of the present study was to investigate the effects of Gln on the intestinal mucosa of HMGB1 expression following IR to determine whether Gln relieved intestinal IR injury in the intestinal mucosal barrier. Forty-eight Sprague-Dawley rats were included in the present study. A model of intestinal ischemia-reperfusion injury was established by clamping the superior mesenteric artery of the rats to cause ischemia, followed by restoring blood flow. The animals were randomly divided into the control (n=24) and the Gln (n=24) groups for the experiments. The two groups of rats were given enteral nutrition with equal heat, nitrogen (heat 125.4 kJ/kg/day, nitrogen 0.2 g/kg/day). The Gln group of rats was fed with enteral nutrition plus 3% Gln, while the control rats were fed with enteral nutrition plus 3% soybean protein. After 7 days, the HMGB1 and plasma levels of NF-κB, TNF-α, IL-1, Gln, D-lactic acid and diamine oxidase (DAO) were observed. The changes in the morphology of intestinal mucosa were observed using electron microscopy. The plasma levels of TNF-α, IL-1, D-lactic acid and DAO, and the level of HMGB1, NF-κB, TNF-α and IL-1 in intestinal mucosa were significantly higher after IR (p<0.05), while the plasma level of Gln was lower in the two groups. In the control group, the plasma level of IL-1, TNF-α, DAO and D-lactic acid, and that of HMGB1, NF-κB, TNF-α, and IL-1 in intestinal mucosa were significantly higher, while the plasma level of Gln was lower than that prior to modeling on the 3rd and 7th days of the experiment. In the Gln group, the plasma level of IL-1, TNF-α, DAO and D-lactic acid, and that of HMGB1, NF-κB, IL-1, and TNF-α in intestinal mucosa were significantly higher (p<0.05) compared to the control on the 3rd and 7th days of the experiment. By contrast, after the 7th day, the plasma level of IL-1, TNF-α, DAO and D-lactic acid, and the level of HMGB1, NF-κB, IL-1, TNF-α in intestinal mucosa were significantly lower in the Gln group, while the plasma level of Gln was significantly higher than those in control group and after IR on the 7th day of the experiment. Additionally, the structure of villi and recess was damaged, villi was sparse and short, and considerable inflammatory cell influx embellished the lamina propria, lymphangiectasia, and edema after IR. On the 7th day, compared to after IR, the intestinal villi and recess structure of the controls was significantly restored in the Gln group. In conclusion, Gln repaired the intestinal mucosal injury in IR by reducing the expression of HMGB1 and inflammatory cytokines, and reducing the permeability of the intestinal mucosa.

The Blood-Brain Barrier Permeability of Lignans and Malabaricones from the Seeds of Myristica fragrans in the MDCK-pHaMDR Cell Monolayer Model

The blood-brain barrier (BBB) permeability of twelve lignans and three phenolic malabaricones from the seeds of Myristica fragrans (nutmeg) were studied with the MDCK-pHaMDR cell monolayer model. The samples were measured by high-performance liquid chromatography and the apparent permeability coefficients (P_app) were calculated. Among the fifteen test compounds, benzonfuran-type, dibenzylbutane-type and arylnaphthalene-type lignans showed poor to moderate permeabilities with P_app values at 10⁻⁸–10⁻⁶ cm/s; those of 8-O-4′-neolignan and tetrahydrofuran-lignan were at 10⁻⁶–10⁻⁵ cm/s, meaning that their permeabilities are moderate to high; the permeabilities of malabaricones were poor as their P_app values were at 10⁻⁸–10⁻⁷ cm/s. To 5-methoxy-dehydrodiisoeugenol (2), erythro-2-(4-allyl-2,6-dimethoxyphenoxy)-1-(3,4-dimethoxyphenyl)-propan-1-ol acetate (6), verrucosin (8), and nectandrin B (9), an efflux way was involved and the main transporter for 6, 8 and 9 was demonstrated to be P-glycoprotein. The time and concentration dependency experiments indicated the main transport mechanism for neolignans dehydrodiisoeugenol (1), myrislignan (7) and 8 was passive diffusion. This study summarized the relationship between the BBB permeability and structure parameters of the test compounds, which could be used to preliminarily predict the transport of a compound through BBB. The results provide a significant molecular basis for better understanding the potential central nervous system effects of nutmeg.

Induction of ROS generation and NF-κB activation in MARC-145 cells by a novel porcine reproductive and respiratory syndrome virus in Southwest of China isolate

Background

Porcine reproductive and respiratory syndrome virus (PRRSV) is the cause of an economically important swine disease that has devastated the swine industry since the late 1980s. The aim of the present study was to investigate the interaction between reactive oxygen species (ROS) and NF-κB by PRRSV infection.

Results

We isolated the local strain of PRRSV from southwest China, designated YN-2011, then sequenced and analyzed the genome. YN-2011 was then used to evaluate the interaction of ROS and NF-κB. In PRRSV infected MARC-145 cells, there was a time-dependent increase in ROS and Maleic Dialdehyde (MDA). Accordingly, NF-κB activation was also increased as PRRSV infection progressed. Degradation of IκB mRNA was detected late in PRRSV infection, and overexpression of the dominant negative form of IκBα significantly suppressed NF-κB induced by PRRSV.

Conclusions

The results indicate that the generation of ROS is involved in PRRSV replication and this progression is associated with the alteration in NF-κB activity induced by ROS. These results should extend our better understanding the interaction between PRRSV and host MARC-145 cells.

Electronic supplementary material

The online version of this article (doi:10.1186/s12917-015-0480-z) contains supplementary material, which is available to authorized users.

α-Tocopherol long-chain metabolite α-13'-COOH affects the inflammatory response of lipopolysaccharide-activated murine RAW264.7 macrophages

SCOPE

Inflammatory response of macrophages is regulated by vitamin E forms. The long-chain metabolite α-13'-carboxychromanol (α-13'-COOH) is formed by hepatic α-tocopherol (α-TOH) catabolism and acts as a regulatory metabolite via pathways that are different from its metabolic precursor.

METHODS AND RESULTS

Using semisynthetically-derived α-13'-COOH we profiled its action on LPS-induced expression of pro- and anti-inflammatory genes using RT-qPCR and of key proteins by Western blotting. Effects on inflammatory response were assessed by measuring production of nitric oxide and prostaglandin (PG) E2 , PGD2 , and PGF2α. α-13'-COOH inhibits proinflammatory pathways in LPS-stimulated RAW264.7 macrophages more efficiently than α-TOH. Profiling inflammation-related genes showed significant blocking of interleukin (Il)1β by the metabolite and its precursor as well, while upregulation of Il6 was not impaired. However, induction of Il10, cyclooxygenase 2 (Cox2) and inducible nitric oxide synthase (iNos) by LPS and consequently the formation of nitric oxide and PG was significantly reduced by α-13'-COOH. Interestingly, α-13'-COOH acted independently from translocation of NFκB subunit p65.

CONCLUSION

Our study sheds new light on the mode of action of α-TOH on the inflammatory response in macrophages, which may be mediated in vivo at least in part by its metabolite α-13'-COOH. Our data show that α-13'-COOH is a potent anti-inflammatory molecule.

Anti-inflammatory activity of polyphenolics from açai (Euterpe oleracea Martius) in intestinal myofibroblasts CCD-18Co cells

This is the first time that the anti-inflammatory activities of açai polyphenols relevant to intestinal inflammation were demonstrated in colon fibroblasts cells.

Pristimerin, a natural anti-tumor triterpenoid, inhibits LPS-induced TNF-α and IL-8 production through down-regulation of ROS-related classical NF-κB pathway in THP-1 cells

Pristimerin, a naturally occurring quinonemethide triterpenoid compound, is known to exert a variety of pharmacological activities. In the present study, we investigated the molecular actions of pristimerin against LPS-induced inflammatory responses in human monocytic THP-1 cells. The results showed that pristimerin inhibited the production of TNF-α and IL-8 in a dose-dependent manner. To explore the possible mechanisms underlying these inhibitions by pristimerin, we examined the intracellular ROS level and the NF-κB protein signaling pathway. Pristimerin clearly scavenged LPS-induced intracellular ROS production. In addition, pristimerin prevented LPS-induced NF-κB activation through the inhibition of phosphorylation of IKKα/β, phosphorylation and degradation of IκBα, as well as phosphorylation and nuclear translocation of NF-κB p65. These findings suggest that pristimerin down-regulates the expression of pro-inflammatory mediators through blocking of NF-κB activation by inhibiting interconnected ROS/IKK/NF-κB signaling pathways.

Abarema cochliacarpos reduces LPS-induced inflammatory response in murine peritoneal macrophages regulating ROS-MAPK signal pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Abarema cochliacarpos (Gomes) Barneby and Grimes (Fabaceae), known by the vulgar name of Babatenã, has been traditionally used in Northeast Brazil, as an anti-inflammatory remedy. Previous studies have demonstrated its anti-inflammatory and antiulcer effects in skin lesion, alcohol gastric ulcer and acute and chronic colitis.

AIMS

The present study was designed to evaluate the antioxidant and anti-inflammatory effects of the butanolic fraction from A. cochliacarpos (BFAC) and its major flavonoid, (+)-catechin, in LPS-stimulated murine peritoneal macrophages. Moreover, we studied the role of mitogen-activated protein kinase (MAPK)s and NF-kB signaling pathways possibly involved in the beneficial effects.

MATERIALS AND METHODS

The quantification of the extract was carried out by ultra-performance liquid chromatography analysis. Cell viability was determined using SRB assay. Nitric oxide (NO) production was analyzed by Griess method and intracellular reactive oxygen species (ROS) by fluorescence analysis. In addition, cyclooxygenase (COX-2) and inducible nitric oxide synthase (iNOS) expression, MAPK activation and IkappaBalpha (IKBα) degradation, were determined by Western blot.

RESULTS

After BFAC characterization, (+)-catechin was revealed as its major constituent. Both BFAC and (+)-catechin, exerted significant anti-oxidant and anti-inflammatory effects inhibiting LPS-induced intracellular ROS and NO production in peritoneal macrophages. Additionally, the extract but also its major component reduced pro-inflammatory proteins expression probably through c-Jun N-terminal kinase and p38 MAPK signaling pathways.

CONCLUSION

These data suggest that the beneficial effects of BFAC might be mediated, at least in part, by the presence of (+)-catechin. Conclusively our findings confirm the potential of A. cochliacarpos as a new therapeutic strategy for the management of inflammatory and oxidative stress-related diseases.

Anti-platelet activity of erythro-(7S,8R)-7-acetoxy-3,4,3',5'-tetramethoxy-8-O-4'-neolignan from Myristica fragrans

Platelets play a critical role in pathogenesis of cardiovascular disorders and strokes. The inhibition of platelet function is beneficial for the treatment and prevention of these diseases. In this study, we investigated the anti-platelet activity of erythro-(7S,8R)-7-acetoxy-3,4,3',5'-tetramethoxy-8-O-4'-neolignan (EATN), a neolignan isolated from Myristica fragrans, using human platelets. EATN preferentially inhibited thrombin- and platelet-activating factor (PAF)-induced platelet aggregation without affecting platelet damage in a concentration-dependent manner with IC50 values of 3.2 ± 0.4 and 3.4 ± 0.3 μM, respectively. However, much higher concentrations of EATN were required to inhibit platelet aggregation induced by arachidonic acid. EATN also inhibited thrombin-induced serotonin and ATP release, and thromboxane B2 formation in human platelets. Moreover, EATN caused an increase in cyclic AMP (cAMP) levels and attenuated intracellular Ca(2+) mobilization in thrombin-activated human platelets. Therefore, we conclude that the inhibitory mechanism of EATN on platelet aggregation may increase cAMP levels and subsequently inhibit intracellular Ca(2+) mobilization by interfering with a common signaling pathway rather than by directly inhibiting the binding of thrombin or PAF to their receptors. This is the first report of the anti-platelet activity of EATN isolated from M. fragrans.