In vitro anti-inflammatory and pro-aggregative effects of a lipid compound, petrocortyne A, from marine sponges

Natural and Bioinspired Lipidic Alkynylcarbinols as Leishmanicidal, Antiplasmodial, Trypanocidal, Fungicidal, Antibacterial, and Antimycobacterial Agents

The present review article recapitulates for the first time the antipathogenic biological data of a series of lipidic natural products and synthetic analogues thereof characterized by the presence in their structure of an alkynylcarbinol unit. The cytotoxic properties of such natural and bioinspired compounds have been covered by several literature overviews, but to date, no review article detailing their activity against pathogens has been proposed. This article thus aims at providing a comprehensive overview of the field including early studies from the 1970s and 1980s with a specific focus on results published from the late 1990s until nowadays. Publications presenting the data of almost 50 different natural products are reported. Detailed activities encompass the fields of leishmanicidal, antiplasmodial, trypanocidal, fungicidal, and mainly antibacterial and antimycobacterial compounds. The few published studies aimed at exploring the structure-activity relationship in these series are also described. Around 15 different synthetic analogues of natural products, selected among the most active reported, are also presented. The rare data available regarding the antipathogenic mode of action of these products are recalled, and finally, a comparative analysis of the available biological data is proposed with the aim of identifying the key structural determinants for the bioactivity against pathogens of these unusual compounds.

Marine Microorganism Molecules as Potential Anti-Inflammatory Therapeutics

The marine environment represents a formidable source of biodiversity, is still largely unexplored, and has high pharmacological potential. Indeed, several bioactive marine natural products (MNPs), including immunomodulators, have been identified in the past decades. Here, we review how this reservoir of bioactive molecules could be mobilized to develop novel anti-inflammatory compounds specially produced by or derived from marine microorganisms. After a detailed description of the MNPs exerting immunomodulatory potential and their biological target, we will briefly discuss the challenges associated with discovering anti-inflammatory compounds from marine microorganisms.

New Bioactive Polyacetylenes from the Marine Sponge Petrosia sp

Three new polyacetylenes, pellynols P (1), Q (2), and R (3) were isolated from the marine sponge Petrosia sp., along with the known compound pellynol H (4). Their structures were determined by analyses of extensive NMR, HR-MS, and ESI-MS/MS data. All compounds displayed potent cytotoxicities against human hepatocellular carcinoma HepG2, human melanoma A375, and human colorectal carcinoma HT29 cell lines with IC₅₀ values at the range of 1.4-4.4 μM.

Oceans as a Source of Immunotherapy

Marine flora is taxonomically diverse, biologically active, and chemically unique. It is an excellent resource, which offers great opportunities for the discovery of new biopharmaceuticals such as immunomodulators and drugs targeting cancerous, inflammatory, microbial, and fungal diseases. The ability of some marine molecules to mediate specific inhibitory activities has been demonstrated in a range of cellular processes, including apoptosis, angiogenesis, and cell migration and adhesion. Immunomodulators have been shown to have significant therapeutic effects on immune-mediated diseases, but the search for safe and effective immunotherapies for other diseases such as sinusitis, atopic dermatitis, rheumatoid arthritis, asthma and allergies is ongoing. This review focuses on the marine-originated bioactive molecules with immunomodulatory potential, with a particular focus on the molecular mechanisms of specific agents with respect to their targets. It also addresses the commercial utilization of these compounds for possible drug improvement using metabolic engineering and genomics.

In vitro and in vivo inhibitory effects of 6-hydroxyrubiadin on lipopolysaccharide-induced inflammation

Inflammation is a defensive response against a multitude of harmful stimuli and stress conditions such as tissue injury, and is one of the most common pathological processes of human diseases. 6-Hydroxyrubiadin, an anthraquinone isolated from Rubia cordifolia L., exhibits several bioactive properties. The aim of this study was to evaluate whether 6-hydroxyrubiadin can reduce the production of pro-inflammatory cytokines and ameliorate acute lung injury (ALI) in a mouse model. In this study, we demonstrated that 6-hydroxyrubiadin suppressed lipopolysaccharide (LPS)-induced nuclear factor-kappa B activation as well as the phosphorylation of c-Jun N-terminal kinase in RAW 264.7 macrophages. In addition, we also showed that 6-hydroxyrubiadin inhibited the expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6 in phorbol myristate acetate (PMA)-primed U937 and RAW 264.7 cells. Furthermore, 6-hydroxyrubiadin treatment reduced the production of these cytokines in vivo and attenuated the severity of LPS-induced ALI. Thus, these results suggested that 6-hydroxyrubiadin may be a potential therapeutic candidate for the treatment of inflammation and inflammatory diseases.

In vitro and in vivo anti-inflammatory effects of theaflavin-3,3'-digallate on lipopolysaccharide-induced inflammation

Inflammation is a defensive response against various harmful stimuli and stress conditions, such as tissue injury and one of the most common pathological processes occurring in human diseases. Theaflavin-3,3'-digallate, one of the theaflavins present in black tea, exhibits several bioactive properties, including the ability to lower the incidence of coronary heart disease, a positive effect on the bone mineral density, and the ability to prevent cancer. The aim of this study was to evaluate whether theaflavin-3,3'-digallate could reduce the production of pro-inflammatory cytokines in vivo and in vitro and ameliorate acute lung injury (ALI) in a mouse model. In this study, we demonstrated that theaflavin-3,3'-digallate suppressed the lipopolysaccharide (LPS)-induced phosphorylation of c-Jun N-terminal kinase and p38 mitogen-activated protein kinase in RAW 264.7 macrophages. In addition, we also showed that theaflavin-3,3'-digallate inhibited the expression of tumor necrosis factor alpha, interleukin -1 beta, and interleukin 6 in phorbol myristate acetate -primed U937 and RAW 264.7 cells. Furthermore, theaflavin-3,3'-digallate treatment attenuated the severity of LPS-induced ALI in mice. These results suggested that theaflavin-3,3'-digallate might be a potential therapeutic candidate for the treatment of inflammation and inflammatory diseases.

Cystoseira usneoides: A Brown Alga Rich in Antioxidant and Anti-inflammatory Meroditerpenoids

Twelve new meroditerpenoids, 1-12, along with eight known compounds, have been isolated from the brown alga Cystoseira usneoides collected off the coast of Tarifa (Spain). The structures of the new metabolites have been established by spectroscopic techniques. All of the new compounds consist of a toluhydroquinone-derived nucleus linked to a regular diterpenoid moiety, which can either be acyclic or contain an ether ring. Most structural diversity arises from the presence of different oxygenated functionalities and unsaturations along the two terminal isoprenoid units of the diterpene backbone. Twelve of the isolated meroditerpenes have been tested in antioxidant assays. All of them have shown radical-scavenging activity. The most active compounds were cystodiones G (1) and H (2), 11-hydroxyamentadione (15), and amentadione (16), which exhibited antioxidant activities in the range of 77-87% that of the Trolox standard. In anti-inflammatory assays, cystodiones G (1) and M (6), cystone C (9), 11-hydroxyamentadione (15), and amentadione (16) showed significant activity as inhibitors of the production of the proinflammatory cytokine TNF-α in LPS-stimulated THP-1 human macrophages.

Chiral alkynylcarbinols from marine sponges: asymmetric synthesis and biological relevance

Covering: up to March 2014. Previous review on the topic: B. W. Gung, C. R. Chim., 2009, 12, 489-505. Chiral α-functional lipidic propargylic alcohols extracted from marine sponges, in particular of the pacific genus Petrosia, constitute a class of acetylenic natural products exhibiting remarkable in vitro biological activities, especially anti-tumoral cytotoxicity. These properties, associated to functionalities that are uncommon among natural products, have prompted recent projects on asymmetric total synthesis. On the basis of a three-sector structural typology, three main sub-types of secondary alkynylcarbinols (with either alkyl, alkenyl, or alkynyl as the second substituent) can be identified as the minimal pharmacophoric units. Selected natural products containing these functionalities have been targeted using previously known or on purpose-designed procedures, where the stereo-determining step can be: (i) a C-C bond forming reaction (e.g. the Zn-mediated addition of alkynyl nucleophiles to aldehydes in the presence of chiral aminoalcohols), (ii) a functional layout (e.g. the asymmetric organo- or metallo-catalytic reduction of ynones), or (iii) an enantiomeric resolution (e.g. a lipase-mediated kinetic resolution via acetylation). The promising medicinal importance of these targets is finally surveyed, and future investigation prospects are proposed, such as: (i) further total synthesis of known or future extraction products; (ii) the synthesis of non-natural analogues, with simpler lipophilic environments of the alkynylcarbinol-based pharmacophoric units; (iii) the variation and optimization of both the pharmacophoric units and their lipophilic environment; and (iv) investigations into the biological mode of action of these unique structures.

Anti-inflammatory activity of AP-SF, a ginsenoside-enriched fraction, from Korean ginseng

BACKGROUND

Korean ginseng is an ethnopharmacologically valuable herbal plant with various biological properties including anticancer, antiatherosclerosis, antidiabetic, and anti-inflammatory activities. Since there is currently no drug or therapeutic remedy derived from Korean ginseng, we developed a ginsenoside-enriched fraction (AP-SF) for prevention of various inflammatory symptoms.

METHODS

The anti-inflammatory efficacy of AP-SF was tested under in vitro inflammatory conditions including nitric oxide (NO) production and inflammatory gene expression. The molecular events of inflammatory responses were explored by immunoblot analysis.

RESULTS

AP-SF led to a significant suppression of NO production compared with a conventional Korean ginseng saponin fraction, induced by both lipopolysaccharide and zymosan A. Interestingly, AP-SF strongly downregulated the mRNA levels of genes for inducible NO synthase, tumor necrosis factor-α, and cyclooxygenase) without affecting cell viability. In agreement with these observations, AP-SF blocked the nuclear translocation of c-Jun at 2 h and also reduced phosphorylation of p38, c-Jun N-terminal kinase, and TAK-1, all of which are important for c-Jun translocation.

CONCLUSION

Our results suggest that AP-SF inhibits activation of c-Jun-dependent inflammatory events. Thus, AP-SF may be useful as a novel anti-inflammatory remedy.

Spongionella secondary metabolites protect mitochondrial function in cortical neurons against oxidative stress

The marine habitat provides a large number of structurally-diverse bioactive compounds for drug development. Marine sponges have been studied over many years and are found to be a rich source of these bioactive chemicals. This study is focused on the evaluation of the activity of six diterpene derivatives isolated from Spongionella sp. on mitochondrial function using an oxidative in vitro stress model. The test compounds include the Gracilins (A, H, K, J and L) and tetrahydroaplysulphurin-1. Compounds were co-incubated with hydrogen peroxide for 12 hours to determine their protective capacities and their effect on markers of apoptosis and Nrf2/ARE pathways was evaluated. Results conclude that Gracilins preserve neurons against oxidative damage, and that in particular, tetrahydroaplysulphurin-1 shows a complete neuroprotective activity. Oxidative stress is linked to mitochondrial dysfunction and consequently to neurodegenerative disorders like Parkinson and Alzheimer diseases, Friedreich ataxia or Amyotrophic lateral sclerosis. This neuroprotection against oxidation conditions suggest that these metabolites could be interesting lead candidates in drug development for neurodegenerative diseases.

JAK2-targeted anti-inflammatory effect of a resveratrol derivative 2,4-dihydroxy-N-(4-hydroxyphenyl)benzamide

Chemical derivatization of resveratrol has been widely conducted in an effort to overcome its chemical instability and therapeutic potential. In the present study, we examined the anti-inflammatory effects of resveratrol derivatives containing an amide functionality using in vitro macrophage models that were stimulated by Toll-like receptor (TLR) ligands, and using several animal inflammatory disease models. Of the resveratrol derivatives tested, compound 8 (2,4-dihydroxy-N-(4-hydroxyphenyl)benzamide) most strongly inhibited the production of nitric oxide (NO), tumor necrosis factor (TNF)-α, and prostaglandin E2 (PGE2), as well as the mRNA expression of inducible NO synthase (iNOS), TNF-α, and cyclooxygenase (COX)-2 in lipopolysaccharide (LPS)-activated RAW264.7 cells, differentiated U937 cells, and peritoneal macrophages. The inhibitory activity of compound 8 was apparently mediated by suppressing the phosphorylation of signal transducer and activator of transcription (STAT)-1, STAT-3, STAT-5, and interferon regulatory factor (IRF)-3. The direct target of compound 8 was revealed to be Janus kinase 2 (JAK2) but not TANK-binding kinase (TBK) 1 using the direct kinase assay and analyses of complex formation with these molecules. Additionally, upstream kinase of TBK1 seems to be also inhibited by compound 8. This compound also strongly ameliorated mouse inflammatory symptoms seen in arachidonic acid-induced ear edema, dextran sodium sulfate (DSS)-treated colitis, EtOH/HCl-induced gastritis, collagen type II-triggered arthritis, and acetic acid-induced writhing. Therefore, of the resveratrol derivatives that we tested, compound 8 was determined to have the strongest anti-inflammatory activities in vitro and in vivo and may potentially be developed for use as a novel anti-inflammatory drug.

Marine bioactives: pharmacological properties and potential applications against inflammatory diseases

Inflammation is a hot topic in medical research, because it plays a key role in inflammatory diseases: rheumatoid arthritis (RA) and other forms of arthritis, diabetes, heart diseases, irritable bowel syndrome, Alzheimer's disease, Parkinson's disease, allergies, asthma, even cancer and many others. Over the past few decades, it was realized that the process of inflammation is virtually the same in different disorders, and a better understanding of inflammation may lead to better treatments for numerous diseases. Inflammation is the activation of the immune system in response to infection, irritation, or injury, with an influx of white blood cells, redness, heat, swelling, pain, and dysfunction of the organs involved. Although the pathophysiological basis of these conditions is not yet fully understood, reactive oxygen species (ROS) have often been implicated in their pathogenesis. In fact, in inflammatory diseases the antioxidant defense system is compromised, as evidenced by increased markers of oxidative stress, and decreased levels of protective antioxidant enzymes in patients with rheumatoid arthritis (RA). An enriched diet containing antioxidants, such as vitamin E, vitamin C, β-carotene and phenolic substances, has been suggested to improve symptoms by reducing disease-related oxidative stress. In this respect, the marine world represents a largely untapped reserve of bioactive ingredients, and considerable potential exists for exploitation of these bioactives as functional food ingredients. Substances such as n-3 oils, carotenoids, vitamins, minerals and peptides provide a myriad of health benefits, including reduction of cardiovascular diseases, anticarcinogenic and anti-inflammatory activities. New marine bioactives are recently gaining attention, since they could be helpful in combating chronic inflammatory degenerative conditions. The aim of this review is to examine the published studies concerning the potential pharmacological properties and application of many marine bioactives against inflammatory diseases.

Inhibitory effect of Sanguisorba officinalis ethanol extract on NO and PGE₂ production is mediated by suppression of NF-κB and AP-1 activation signaling cascade

AIM OF THE STUDY

Sanguisorba officinalis, a well known valuable medicinal plant in Korea, China and Japan used traditionally for the treatment of inflammatory and metabolic diseases such as diarrhea, chronic intestinal infections, duodenal ulcers, and bleeding. Recent studies have revealed that its aqueous or ethanolic extracts exhibit a variety of pharmacological activities such as anti-oxidative, anti-cancer, anti-lipid peroxidation, anti-atherogenic, and vasorelaxant effects. Systematic studies on the anti-inflammatory effect of this plant and its molecular mechanisms have not yet been fully investigated. Ethanol extract of Sanguisorba officinalis (So-EE) the lipopolysaccharide (LPS)-stimulated macrophages and production of inflammatory mediators were employed to assess these properties.

RESULTS

So-EE significantly suppressed the production of nitric oxide (NO) and prostaglandin (PG) E(2) from LPS-activated RAW264.7 cells and peritoneal macrophages in a dose-dependent manner. This extract effectively diminished the mRNA levels of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2, implying that the blockade is generated at the transcriptional level. So-EE strongly blocked the activation and translocation of NF-κB and AP-1 by suppressing the upstream kinases including inhibitor of κBα (IκBα), IκBα kinase (IKK), Akt (protein kinase B), phosphoinositide-dependent kinase 1 (PDK1), p85/phosphoinositide-3-kinase (PI3K), and mitogen activated protein kinase (MAPK) such as extracellular signal-regulated kinase (ERK), p38, and c-Jun N-terminal kinase (JNK). Moreover, So-EE suppressed the phosphorylation of Src, its kinase activity, and complex formation between Src and p85.

CONCLUSION

This study suggests that So-EE has a potent anti-inflammatory activity mediated by NF-κB, and AP-1 inhibitory properties linked to the suppression of Src and MAPK activation.

Regulatory effect of cinnamaldehyde on monocyte/macrophage-mediated inflammatory responses

Cinnamaldehyde (CA) has been known to exhibit anti-inflammatory and anticancer effects. Although numerous pharmacological effects have been demonstrated, regulatory effect of CA on the functional activation of monocytes and macrophages has not been fully elucidated yet. To evaluate its monocyte/macrophage-mediated immune responses, macrophages activated by lipopolysaccharide (LPS), and monocytes treated with proaggregative antibodies, and extracellular matrix protein fibronectin were employed. CA was able to suppress both the production of nitric oxide (NO) and upregulation of surface levels of costimulatory molecules (CD80 and CD69) and pattern recognition receptors (toll-like receptor 2 (TLR2) and complement receptor (CR3)). In addition, CA also blocked cell-cell adhesion induced by the activation of CD29 and CD43 but not cell-fibronectin adhesion. Immunoblotting analysis suggested that CA inhibition was due to the inhibition of phosphoinositide-3-kinase (PI3K) and phosphoinositide-dependent kinase (PDK)1 as well as nuclear factor-(NF-) kappaB activation. In particular, thiol compounds with sulphydryl group, L-cysteine and dithiothreitol (DTT), strongly abrogated CA-mediated NO production and NF-kappaB activation. Therefore, our results suggest that CA can act as a strong regulator of monocyte/macrophage-mediated immune responses by thiolation of target cysteine residues in PI3K or PDK1.

Assignment of the structure of petrocortyne A by mixture syntheses of four candidate stereoisomers

Two different mixture synthesis routes have been used to make the four stereoisomers of petrocortyne A. A first quick and dirty route provided a mixture of the four isomers in nonselective fashion. Mosher and 2-naphthylmethoxyacetic acid (NMA) ester methods were developed to identify the components, and the mixture was partially resolved on analytical chiral HPLC to give the two pure enantiomers of petrocortyne A and the racemate of its diastereomer. A second fluorous mixture synthesis produced all four isomers of petrocortyne A in individual pure form. Comparison of spectra of Mosher derivatives of the synthetic isomers with two supposedly different natural products showed that both natural samples were instead identical and had the (3S,14S) configuration. Likewise, petrocortynes B, D, and F-H are (3S,14S) and petrocortyne D is (3R,14S). Having access to all possible candidate isomers of both petrocortyne A and its Mosher derivatives provided a secure structure assignment not so much because one of the isomers matched the natural product, but because all of the other isomers did not.

Hydroquinone modulates reactivity of peroxynitrite and nitric oxide production

Peroxynitrite (ONOO−), a potent cytotoxic oxidant formed by the reaction of nitric oxide (*NO) and superoxide radical (*O2−), may be rapidly lethal in a cellular milieu due to oxidization and nitration processes. In the present study, hydroquinone displayed strong ONOO− scavenging activity and inhibitory effect on NO production in murine macrophage RAW264.7 cells. Hydroquinone strongly scavenged ONOO− induced dihydrorhodamine 123 oxidation in a dose-dependent manner compared with other reactive species such as *O2− and *NO. Hydroquinone also decreased levels of ONOO− induced nitrotyrosine of glutathione reductase and consequently prevented the enzyme from ONOO− induced damage. Furthermore, hydroquinone suppressed NO production, a cellular pathway for ONOO− formation, in lipopolysaccharide-activated RAW264.7 cells via inhibition of inducible NO synthase expression. The inhibitory effect by hydroquinone seems to be mediated by interruption of lipopolysaccharide-induced signalling such as activation of nuclear factor-kB and extracellular signal-related kinases 1 and 2. The results suggest that hydroquinone may potently modulate reactivity of ONOO− and may therefore be a useful agent against ONOO− mediated diseases.

Suppressive effect of hydroquinone, a benzene metabolite, on in vitro inflammatory responses mediated by macrophages, monocytes, and lymphocytes

We investigated the inhibitory effects of hydroquinone on cytokine release, phagocytosis, NO production, ROS generation, cell-cell/cell fibronectin adhesion, and lymphocyte proliferation. We found that hydroquinone suppressed the production of proinflammatory cytokines [tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and IL-6], secretion of toxic molecules [nitric oxide (NO) and reactive oxygen species (ROS)], phagocytic uptake of FITC-labeled dextran, upregulation of costimulatory molecules, U937 cell-cell adhesion induced by CD18 and CD29, and the proliferation of lymphocytes from the bone marrow and spleen. Considering that (1) environmental chemical stressors reduce the immune response of chronic cigarette smokers and children against bacterial and viral infections and that (2) workers in petroleum factories are at higher risk for cancer, our data suggest that hydroquinone might pathologically inhibit inflammatory responses mediated by monocytes, macrophages, and lymphocytes.

Src kinase-targeted anti-inflammatory activity of davallialactone from Inonotus xeranticus in lipopolysaccharide-activated RAW264.7 cells

BACKGROUND AND PURPOSE

Mushrooms are popular both as food and as a source of natural compounds of biopharmaceutical interest. Some mushroom-derived compounds such as beta-glucan have been shown to be immunostimulatory; this study explores the anti-inflammatory properties of hispidin analogues derived from the mushroom, Inonotus xeranticus. We sought to identify the molecular mechanism of action of these hispidin analogues by determining their effects on lipopolysaccharide (LPS)-mediated inflammatory responses in a macrophage cell line.

EXPERIMENTAL APPROACH

The production of inflammatory mediators was determined by Griess assay, reverse transcription-PCR and ELISA. The inhibitory effect of davalliactone on LPS-induced activation of signalling cascades was assessed by western blotting, immunoprecipitation and direct kinase assay.

KEY RESULTS

In activated RAW264.7 cells, davallialactone strongly downregulated LPS-mediated inflammatory responses, including NO production, prostaglandin E2 release, expression of proinflammatory cytokine genes and cell surface expression of co-stimulatory molecules. Davallialactone treatment did not alter cell viability or morphology. Davallialactone was found to exert its anti-inflammatory effects by inhibiting a signalling cascade that activates nuclear factor kappa B via PI3K, Akt and IKK, but not mitogen-activated protein kinases. Treatment with davallialactone affected the phosphorylation of these signalling proteins, but not their level of expression. These inhibitory effects were not due to the interruption of toll-like receptor 4 binding to CD14. In particular, davallialactone strongly inhibited the LPS-induced phosphorylation and kinase activity of Src, implying that Src may be a potential pharmacological target of davallialactone.

CONCLUSIONS AND IMPLICATIONS

Our data suggest that davallialactone, a small molecule found in edible mushrooms, has anti-inflammatory activity. Davallialactone can be developed as a pharmaceutically valuable anti-Src kinase agent.

Effect of L-cycloserine on cellular responses mediated by macrophages and T cells

In this study, we examined the immunoregulatory roles of L-cycloserine (L-CS), a sphingolipid metabolism regulator with inhibitory activity of serine palmitoyltransferase (SPT), on immune responses mediated by monocytes/macrophages and T cells. Mitogenic responses of splenic lymphocytes induced by LPS, PHA, and Con A were very strongly suppressed by L-CS with IC(50) values ranging from 0.5 to 1 muM. In contrast, this compound less strongly blocked IL-2-induced CD8+ CTLL-2 cell proliferation with an IC(50) value of 540 muM. Interestingly, L-CS enhanced the number of IL-4-producing helper T cells, indicating the favored induction of Th2 condition. Although tumor necrosis factor (TNF)-alpha and nitric oxide (NO) production was not altered under 10% FCS condition, U937 cell-cell adhesion as well as the surface level of adhesion molecules (CD29 and CD98) were significantly suppressed by L-CS. In particular, reduced serum level (5%) under L-CS treatment strongly enhanced the production of TNF-alpha and the inhibitory potency of NO production and cell adhesion. Finally, sphingolipids (D-sphingosine and DL-dihydrosphingosine) did not remarkably abrogate L-CS-mediated T cell proliferation. Therefore our data suggest that de novo sphingolipid metabolism may represent an important aspect of immunomodulatory activities mediated by T cells and macrophages/monocytes, depending on serum level.

Marine pharmacology in 2003-4: marine compounds with anthelmintic antibacterial, anticoagulant, antifungal, anti-inflammatory, antimalarial, antiplatelet, antiprotozoal, antituberculosis, and antiviral activities; affecting the cardiovascular, immune and nervous systems, and other miscellaneous mechanisms of action

The current marine pharmacology review that covers the peer-reviewed literature during 2003 and 2004 is a sequel to the authors' 1998-2002 reviews, and highlights the preclinical pharmacology of 166 marine chemicals derived from a diverse group of marine animals, algae, fungi and bacteria. Anthelmintic, antibacterial, anticoagulant, antifungal, antimalarial, antiplatelet, antiprotozoal, antituberculosis or antiviral activities were reported for 67 marine chemicals. Additionally 45 marine compounds were shown to have significant effects on the cardiovascular, immune and nervous system as well as possessing anti-inflammatory effects. Finally, 54 marine compounds were reported to act on a variety of molecular targets and thus may potentially contribute to several pharmacological classes. Thus, during 2003-2004, research on the pharmacology of marine natural products which involved investigators from Argentina, Australia, Brazil, Belgium, Canada, China, France, Germany, India, Indonesia, Israel, Italy, Japan, Mexico, Morocco, the Netherlands, New Zealand, Norway, Panama, the Philippines, Portugal, Russia, Slovenia, South Korea, Spain, Thailand, Turkey, United Kingdom, and the United States, contributed numerous chemical leads for the continued global search for novel therapeutic agents with broad spectrum activity.

Inhibitory effect of curcumin on nitric oxide production from lipopolysaccharide-activated primary microglia

Curcumin has been shown to exhibit anti-inflammatory, antimutagenic, and anticarcinogenic activities. However, the modulatory effect of curcumin on the functional activation of primary microglial cells, brain mononuclear phagocytes causing the neuronal damage, largely remains unknown. The current study examined whether curcumin influenced NO production in rat primary microglia and investigated its underlying signaling pathways. Curcumin decreased NO production in LPS-stimulated microglial cells in a dose-dependent manner, with an IC(50) value of 3.7 microM. It also suppressed both mRNA and protein levels of inducible nitric oxide synthase (iNOS), indicating that this drug may affect iNOS gene expression process. Indeed, curcumin altered biochemical patterns induced by LPS such as phosphorylation of all mitogen-activated protein kinases (MAPKs), and DNA binding activities of nuclear factor-kappaB (NF-kappaB) and activator protein (AP)-1, assessed by reporter gene assay. By analysis of inhibitory features of specific MAPK inhibitors, a series of signaling cascades including c-Jun N-terminal kinase (JNK), p38 and NF-kappaB was found to play a critical role in curcumin-mediated NO inhibition in microglial cells. The current results suggest that curcumin is a promising agent for the prevention and treatment of both NO and microglial cell-mediated neurodegenerative disorders.

Radical scavenging and anti-inflammatory activity of extracts from Opuntia humifusa Raf

Opuntia humifusa Raf. (O. humifusa Raf.) is a member of the Cactaceae family. To determine the antioxidative and anti-inflammatory effects of this herb, various solvent fractions (methanol, hexane, chloroform, ethyl acetate, butanol, and water) prepared from the leaves of cacti were tested using DPPH (2,2-diphenyl-l-picrylhydrazyl radical) and xanthine oxidase assays, and nitric oxide (NO)-producing macrophage cells. We found that O. humifusa Raf. displayed potent antioxidative and anti-inflammatory activity. Thus, all solvent fractions, except for the water layer, showed potent scavenging effects. The scavenging effect of the ethyl acetate fraction was higher than that of the other fractions, with IC50 values of 3.6 and 48.2 microg mL(-1). According to activity-guided fractionation, one of the active radical scavenging principles in the ethyl acetate fraction was found to be quercetin. In contrast, only two fractions (chloroform and ethyl acetate) significantly suppressed nitric oxide production from the lipopolysaccharide (LPS)-activated RAW264.7 cells. In addition, chloroform and ethyl acetate fractions significantly blocked the expression of inducible nitric oxide synthetase (iNOS) and interleukin-6 (IL-6) from the RAW264.7 cells stimulated by LPS. Moreover, ethyl acetate fractions significantly blocked the expression of IL-1beta from the RAW264.7 cells stimulated by LPS. Therefore, the results suggested that O. humifusa Raf. may modulate radical-induced toxicity via both direct scavenging activity and the inhibition of reactive species generation, and the modulation of the expression of inflammatory cytokines. Finally, O. humifusa Raf. may be useful as a functional food or drug against reactive species-mediated disease.

Cynaropicrin, a sesquiterpene lactone, as a new strong regulator of CD29 and CD98 functions

Cynaropicrin is a sesquiterpene lactone displaying immunomodulatory effects on the production of cytokine and nitric oxide from macrophages/monocytes. In this study we have examined inhibitory effect of cynaropicrin on activation of major adhesion molecules [CD29 (beta1 integrins), CD43, and CD98] on the cells assessed by U937 (promonocytic cells) homotypic aggregation. Cynaropicrin potently blocked CD29 (beta1 integrins)- and CD98-induced homotypic aggregation with IC(50) values of 3.46 and 2.98 microM, respectively, without displaying cytotoxicity. Similarly, flow cytometric analysis exhibited that cynaropicrin down-regulated strikingly surface level of CD29 and CD147, a functional regulator of CD98, but not CD43. More importantly, cynaropicrin inhibition was linked to blockade of extracellular signal-related kinase (ERK) activation and distinct from other enzyme inhibitors including rottlerin, propranolol, forskolin, and chloroquine, but not cytochalasin B. Therefore, our finding is the first demonstration that cynaropicrin may be a potent functional regulator of CD29 and CD98 via interrupting ERK activation which may be linked to cytoskeleton rearrangement, suggesting further application to CD29- and CD98-mediated diseases such as virus-induced chronic inflammation, and invasion, migration, and metastasis of leukocyte cancer cells.