Extracellular Vesicles From the Helminth Fasciola hepatica Prevent DSS-Induced Acute Ulcerative Colitis in a T-Lymphocyte Independent Mode.

The complexity of the pathogenesis of inflammatory bowel disease (ulcerative colitis and Crohn's disease) has led to the quest of empirically drug therapies, combining immunosuppressant agents, biological therapy and modulators of the microbiota. Helminth parasites have been proposed as an alternative treatment of these diseases based on the hygiene hypothesis, but ethical and medical problems arise. Recent reports have proved the utility of parasite materials, mainly excretory/secretory products as therapeutic agents. The identification of extracellular vesicles on those secreted products opens a new field of investigation, since they exert potent immunomodulating effects. To assess the effect of extracellular vesicles produced by helminth parasites to treat ulcerative colitis, we have analyzed whether extracellular vesicles produced by the parasitic helminth Fasciola hepatica can prevent colitis induced by chemical agents in a mouse model. Adult parasites were cultured in vitro and secreted extracellular vesicles were purified and used for immunizing both wild type C57BL/6 and RAG1-/- mice. Control and immunized mice groups were treated with dextran sulfate sodium 7 days after last immunization to promote experimental colitis. The severity of colitis was assessed by disease activity index and histopathological scores. Mucosal cytokine expression was evaluated by ELISA. The activation of NF-kB, COX-2, and MAPK were evaluated by immunoblotting. Administration of extracellular vesicles from F. hepatica ameliorates the pathological symptoms reducing the amount of pro-inflammatory cytokines and interfering with both MAPK and NF-kB pathways. Interestingly, the observed effects do not seem to be mediated by T-cells. Our results indicate that extracellular vesicles from parasitic helminths can modulate immune responses in dextran sulfate sodium (DSS)-induced colitis, exerting a protective effect that should be mediated by other cells distinct from B- and T-lymphocytes.

Shikonin promotes intestinal wound healing in vitro via induction of TGF-ß release in IEC-18 cells.

The intestinal barrier is a complex system with a dynamic structure that is designed for the maintenance of homeostasis in healthy individuals. Ulcerative colitis, one of the main manifestations of inflammatory bowel disease, is characterized by an inadequate and delayed wound healing. Shikonin, the active principle in the root of Lithospermum erythrorhizon, has demonstrated its ability to attenuate dextran sulfate sodium-induced ulcerative colitis in mice. Moreover, the root of L. erythrorhizon has been used in traditional Chinese medicine for treatment of burns, anal ulcers, hemorrhoids and skin wounds. However, the effect of shikonin on intestinal wound healing is unknown. Using an in vitro model for wound healing, we observed that shikonin enhances cell migration of intestinal epithelial cells through a mechanism that involves TGF-ß1 induction. The combination of shikonin's anti-inflammatory activity together with its wound-healing properties makes it a great potential therapeutic agent for the treatment of injury associated with intestinal inflammation.

Traditional chinese medicine remedy to jury: the pharmacological basis for the use of shikonin as an anticancer therapy.

Shikonin is the major constituent of the root of Lithospermum erythrorhizon, which has been used in traditional Chinese medicine to treat external wounds, burns, or dermatitis for centuries. Nowadays, this root is commonly used as an herbal medicine against cancer. Studies carried out over the past 30 years have demonstrated that many of the effects historically associated with the use of this root have a scientific basis, with shikonin and its derivatives being responsible for its pharmacological properties. These include both anti-inflammatory and anticancer effects. While previous summaries have focused on the pharmacokinetics and toxicity of shikonin, the aim of this review is to report on the most current findings with regard to shikonin's antitumor activity by summarizing and comparing the various studies published in the last ten years and discussing the pharmacological aspects that make shikonin a promising anticancer agent.

Cocoa polyphenols and their potential benefits for human health.

This paper compiles the beneficial effects of cocoa polyphenols on human health, especially with regard to cardiovascular and inflammatory diseases, metabolic disorders, and cancer prevention. Their antioxidant properties may be responsible for many of their pharmacological effects, including the inhibition of lipid peroxidation and the protection of LDL-cholesterol against oxidation, and increase resistance to oxidative stress. The phenolics from cocoa also modify the glycemic response and the lipid profile, decreasing platelet function and inflammation along with diastolic and systolic arterial pressures, which, taken together, may reduce the risk of cardiovascular mortality. Cocoa polyphenols can also modulate intestinal inflammation through the reduction of neutrophil infiltration and expression of different transcription factors, which leads to decreases in the production of proinflammatory enzymes and cytokines. The phenolics from cocoa may thus protect against diseases in which oxidative stress is implicated as a causal or contributing factor, such as cancer. They also have antiproliferative, antimutagenic, and chemoprotective effects, in addition to their anticariogenic effects.

Cucurbitacins as inducers of cell death and a rich source of potential anticancer compounds.

Triterpenes have been reported to induce cell death. One relevant group of this family of compounds is cucurbitacins, which have been studied as inducers of apoptosis in various cancer cell lines. The most significant mechanisms with regard to the apoptotic effects of cucurbitacins are their ability to modify transcriptional activities via nuclear factors or genes and their capability to activate or inhibit pro- or anti-apoptotic proteins. Still, while the majority of studies on these compounds have dealt with their apoptotic effects on cancer cell lines, several research groups have also explored their anti-inflammatory activities. In general, cucurbitacins are considered to be selective inhibitors of the JAK/STAT pathways; however, other mechanisms may be implicated in their apoptotic effects, including the MAPK pathway (known to be important for cancer cell proliferation and survival), PARP cleavage, expression of active caspase-3, decreased pSTAT3 and JAK3 levels, as well as decreases in various downstream STAT3 targets such as Mcl-1, Bcl-2, Bcl-xL, and cyclin D3, all of which are implicated in apoptosis and the cell cycle. Taking all these effects into account, cucurbitacins may prove useful in the treatment of different kinds of cancers, especially when used with other cytostatic agents.

Anti-inflammatory agents from plants: progress and potential.

The identification of substances that can promote the resolution of inflammation in a way that is homeostatic, modulatory, efficient, and well-tolerated by the body is of fundamental importance. Traditional medicines have long provided front-line pharmacotherapy for many millions of people worldwide. Medicinal extracts are a rich source of therapeutic leads for the pharmaceutical industry. The use of medicinal plant therapies to treat chronic illness, including rheumatoid arthritis (RA) and inflammatory bowel disease (IBD), is thus widespread and on the rise.The aim of this review is to present recent progress in clinical anti-inflammatory studies of plant extracts and compound leads such as green tea polyphenols, curcumin, resveratrol, boswellic acid, and cucurbitacins, among others, against chronic inflammatory diseases, mainly RA and IBD. In this context, the present paper also highlights the most promising experimental data on those plant extracts and pure compounds active in animal models of the aforementioned diseases.

Bcl-2 is a negative regulator of interleukin-1beta secretion in murine macrophages in pharmacological-induced apoptosis.

BACKGROUND AND PURPOSE: Cucurbitacin R, a natural anti-inflammatory product, has been shown to exhibit activity against both adjuvant-induced arthritis and delayed-type hypersensitivity reactions induced by various agents. Previous studies have demonstrated that the effects of cucurbitacin R stem from its inhibition of both cytokine production and lymphocyte proliferation. EXPERIMENTAL APPROACHES: Effects of cucurbitacin R were investigated on lipopolysaccharide-stimulated RAW 264.7 cells. Cell cycle evolution was analysed by flow cytometry, detection of apoptosis by DNA ladder, Bcl-2, p21, p53, Bax, cleaved caspase-1 (p10), caspase-9, and caspase-3, cleaved caspase (p17) and interleukin-1beta detection was followed by Western blot analysis and mRNA expression with quantitative real time reverse transcription-polymerase chain reaction (qRT-PCR). KEY RESULTS: Cucurbitacin R was found to induce apoptosis in lipopolysaccharide-stimulated RAW 264.7 macrophages through the inhibition of Bcl-2 expression, which regulates pro-inflammatory caspase-1 activation and interleukin-1beta release. Also, cucurbitacin R arrested the cell cycle in the G(2)/M phase and increased the subG(0) population in lipopolysaccharide-stimulated RAW 264.7 macrophages. Moreover, it increased the expression of proteins p53 and p21, down-regulated the expression of Bcl-2, activated the activity of caspase-1 and augmented the production of interleukin-1beta. Finally, the transfection of RAW 264.7 macrophages with a Bcl-2 expression plasmid produced the inhibition of apoptosis and caspase-1 activation/interleukin-1beta release induced by cucurbitacin R in RAW 264.7 cells. CONCLUSIONS AND IMPLICATIONS: Taken together, these results point to a new apoptotic process in which interleukin-1beta release is directly regulated by Bcl-2 status; this contributes to the evidence that apoptotic processes do not induce inflammation.

Shikonin reduces oedema induced by phorbol ester by interfering with IkappaBalpha degradation thus inhibiting translocation of NF-kappaB to the nucleus.

BACKGROUND AND PURPOSE: In the present paper we studied the effect of shikonin on ear oedema induced by 12-O-tetradecanoylphorbol-13-acetate (TPA), and determined the mechanisms through which shikonin might exert its topical anti-inflammatory action. EXPERIMENTAL APPROACH: Acute ear oedema was induced in mice by topical application of TPA. The in vitro assays used macrophages RAW 264.7 cells stimulated with lipopolysaccharide. Cyclooxygenase-2, inducible nitric oxide synthase, protein kinase Calpha, extracellular signal-regulated protein kinase (ERK), phosphorylated ERK (pERK), c-Jun N-terminal kinase (JNK), pJNK, p38, p-p38, p65, p-p65, inhibitor protein of nuclear factor-kappaB (NF-kappaB) (IkappaBalpha) and pIkappaBalpha were measured by Western blotting, activation and binding of NF-kappaB to DNA was detected by reporter gene and electrophoretic mobility shift assay, respectively, and NF-kappaB p65 localization was detected by immunocytochemistry. KEY RESULTS: Shikonin reduced the oedema (inhibitory dose 50 = 1.0 mg per ear), the expression of cyclooxygenase-2 (70%) and of inducible nitric oxide synthase (100%) in vivo. It significantly decreased TPA-induced translocation of protein kinase Calpha, the phosphorylation and activation of ERK, the nuclear translocation of NF-kappaB and the TPA-induced NF-kappaB-DNA-binding activity in mouse skin. Moreover, in RAW 264.7 cells, shikonin significantly inhibited the binding of NF-kappaB to DNA in a dose-dependent manner and the nuclear translocation of p65. CONCLUSIONS AND IMPLICATIONS: Shikonin exerted its topical anti-inflammatory action by interfering with the degradation of IkappaBalpha, thus inhibiting the activation of NF-kappaB.

Inhibition of transcription factors by plant-derived compounds and their implications in inflammation and cancer.

Inflammation is a general term used to describe various pathological processes with diverse causes that can include infection, trauma, or an autoimmune response. Due to its many causes, the inflammatory response involves multiple and varied mediators, including vasoactive amines, free radicals, and both lipidic and peptidic mediators. Medicinal plants and the compounds derived from them are a good source of new and specific inhibitors of the inflammatory process. The past decade has witnessed many important discoveries in this field, with new findings challenging the more traditional views of pharmacologists. Various studies, for example, have demonstrated the positive effects of plant-derived phenolics, which act as anti-oxidants, free radical scavengers, and inhibitors of nitric-oxide synthase, cyclooxygenase, and lipoxygenase. The anti-inflammatory activity of chalcones has been correlated with the induction of heme oxygenase-1 while phlorotannins have been found to inhibit matrix metalloproteinase, which is implicated in arthritis, chronic inflammation, and wrinkle formation. Sesquiterpene lactones have been studied as inhibitors of NF-kappaB activity and the relationship between their chemical structure and pharmacological activity has been clearly established. Recently, cucurbitacins have been described as inhibitors of JAK -STAT and NF-AT functions related to inflammation; they were also found to induce apoptosis of cells involved in the inflammatory response. This review focuses mainly on the effects of natural products on transcription factors, which are the most promising targets for designing new active drugs against inflammation and cancer.

In vitro and in vivo effects of Ranunculus peltatus subsp. baudotii methanol extract on models of eicosanoid production and contact dermatitis.

Ranunculus (Crowfoot) species are numerous and they are all reputed to be counter-irritants and are used in several topical conditions. In order to study the pharmacological mechanisms of action underlying this popular use, a methanol extract of Ranunculus peltatus was tested in vitro in various assays involving eicosanoid and human elastase release by intact cells as well as in vivo, with models of delayed-type hypersensitivity (DTH) contact dermatitis. The extract proved to be a selective inhibitor of the cyclooxygenase-1 pathway, producing the total inhibition of 12-(S)-HHTrE release at 200 microg/mL, while leaving both 5-lipoxygenase and 12-lipoxygenase activities unaffected at the same dose. The n-hexane, chloroform and ethyl acetate fractions of the crude methanol extract inhibited LTB(4) release by intact rat peritoneal neutrophils, but more polar fractions were inactive and did not increase the 5-LOX activity as seen previously for extracts of other Ranunculus species. In the in vivo models, the methanol extract reduced the dinitrofluorobenzene (DNFB)-induced oedema by 40%, but failed to inhibit the oedema brought on by oxazolone. The results agree with the age-old assertion that Water Crowfoot species can be used as a topical antiinflammatory remedy without the prominent irritant action that accompanies the application of non-aquatic Ranunculus species.

Demethylnobiletin inhibits delayed-type hypersensitivity reactions, human lymphocyte proliferation and cytokine production.

BACKGROUND AND PURPOSE: Our aim was to examine the effect of demethylnobiletin on various experimental models of delayed-type hypersensitivity (DTH) reactions and to determine its influence on the mediators and enzymes involved in these reactions. EXPERIMENTAL APPROACH: DTH was induced in mice by oxazolone, dinitrofluorobenzene (DNFB) and sheep red blood cells (SRBC). The effect of demethylnobiletin on the ensuing DTH was studied, especially in relation to oedema formation, cell infiltration and tissue damage. Its activity on different mediators implicated in DTH reactions was also determined and its effect on nitric oxide synthase (NOS)-2 analysed. Finally, its influence on T lymphocyte proliferation, apoptosis and caspase 3 activity was tested. KEY RESULTS: DTH reactions were all reduced by demethylnobiletin. The experimental results suggest that the compound may act by reducing cell infiltration and by suppressing mediators such as interleukin-2 (IC50=1.63 microM), interleukin-4 (IC50=2.76 microM), tumour necrosis factor-alpha (IC50=0.66 microM), interferon-gamma (IC50=1.35 microM), and interleukin-1 beta (46% at 2.5 microM) and by concomitantly increasing the production of the anti-inflammatory cytokine, interleukin-10. In addition, while demethylnobiletin affected nitric oxide production, it did not modify NOS-2 expression. Finally, demethylnobiletin inhibited proliferation of T cells and induced their apoptosis. CONCLUSIONS AND IMPLICATIONS: Demethylnobiletin decreased DTH reactions induced by various agents. This finding, along with the fact that the compound has a low toxicity and exhibits several other interesting properties, could pave the way for other structurally related citroflavonoids to be used as pharmacological agents in complementary therapies.

Effects of plant alkylphenols on cytokine production, tyrosine nitration and inflammatory damage in the efferent phase of contact hypersensitivity.

BACKGROUND AND PURPOSE: The phenolic compounds isoprenylhydroquinone glucoside (IHG), 3,5-dicaffeoylquinic acid (DCA), and its methyl ester (DCE) have previously been shown to inhibit both contact hypersensitivity (CHS) and peroxynitrite reactivity. The present work seeks to establish a relationship between the anti-inflammatory effect and the release of cytokines and tyrosine nitration in skin. EXPERIMENTAL APPROACH: Murine CHS was developed by means of sensitization and challenge with dinitrofluorobenzene (DNFB) or oxazolone. Ear swelling was measured 24 and 96 h after challenge. Interleukin (IL)-1beta, IL-4, and tumour necrosis factor (TNF)-alpha were measured by ELISA; and the expression of inducible nitric oxide synthase (iNOS) was detected by Western blotting. Histological samples were analysed for 3-nitrotyrosine. KEY RESULTS: In the oxazolone model, DCE reduced the 24 h swelling by 54% whereas the effect of DCA was lower (40% inhibition). All the test compounds reduced IL-1beta values 24 h after challenge with DNFB or oxazolone, DCE particularly inhibited IL-4 production (74% and 78%, respectively; P<0.01). Tyrosine nitration was also markedly reduced by DCE. In general, the test compounds limited the presence of polymorphonuclear (PMN) leukocytes in the skin. CONCLUSIONS AND IMPLICATIONS: These results suggest that the effect of 3,5-dicaffeoylquinic esters on CHS is associated with a decrease in the production of interleukins, but not with the inhibition of iNOS expression. Moreover, esterification of the carboxyl group at C-1 enhanced protection against tyrosine nitration in the skin.

Anti-inflammatory profile of dehydrocostic acid, a novel sesquiterpene acid with a pharmacophoric conjugated diene.

Sesquiterpene acids are natural products that, in contrast with the thoroughly studied sesquiterpene lactones, have received little pharmacological attention. A good source of this class of compounds is Inula viscosa (Asteraceae), a plant with documented anti-inflammatory effects. The present paper gives the results of our investigations on the biochemical mechanisms involved in the anti-inflammatory activity of one such compound, dehydrocostic acid. The most salient findings were that in vitro dehydrocostic acid inhibits leukotriene B(4) production (IC(50)=22 microM), elastase activity (IC(50)=43 microM) and bee venom phospholipase A(2) activity (IC(50)=17 microM). Furthermore, this sesquiterpenoid was effective on some models of acute edema induced by PLA(2) and 12-O-tetradecanoylphorbol 13-acetate (TPA) Comparison of these data with that known for ilicic acid firmly suggests that the presence of a semiplanar ring A is essential for an improved inhibitory activity on inflammatory mediators.

Medicinal plants and antimicrobial activity.

In the present paper, we analyze the past, present and future of medicinal plants, both as potential antimicrobial crude drugs as well as a source for natural compounds that act as new anti-infection agents. In the past few decades, the search for new anti-infection agents has occupied many research groups in the field of ethnopharmacology. When we reviewed the number of articles published on the antimicrobial activity of medicinal plants in PubMed during the period between 1966 and 1994, we found 115; however, in the following decade between 1995 and 2004, this number more than doubled to 307. In the studies themselves one finds a wide range of criteria. Many focus on determining the antimicrobial activity of plant extracts found in folk medicine, essential oils or isolated compounds such as alkaloids, flavonoids, sesquiterpene lactones, diterpenes, triterpenes or naphtoquinones, among others. Some of these compounds were isolated or obtained by bio-guided isolation after previously detecting antimicrobial activity on the part of the plant. A second block of studies focuses on the natural flora of a specific region or country; the third relevant group of papers is made up of specific studies of the activity of a plant or principle against a concrete pathological microorganism. Some general considerations must be established for the study of the antimicrobial activity of plant extracts, essential oils and the compounds isolated from them. Of utmost relevance is the definition of common parameters, such as plant material, techniques employed, growth medium and microorganisms tested.

Dual inhibition of cyclooxygenase-1 and 5-lipoxygenase by aerial part of Bupleurum fruticescens methanol extract.

The effect of the methanol extract from aerial parts of Bupleurum fruticescens on the release of eicosanoids and hydrolytic enzymes was determined on in vitro cell systems. The extract had a significant effect on 5-lipoxygenase (5-LOX) activity, inhibiting both LTB4 and 5(S)-HETE production with IC50 values of 112 microg/ml and 95 microg/ml, respectively. At concentrations of 200 microg/ml, the extract also inhibited cyclooxygenase-1 (90%) and elastase activities (54%). The 12-LOX activity in intact platelets was not affected; a fact, which suggests that phospholipase A2 (PLA2) activity, is not modified by the extract.

Influence of traditional Chinese anti-inflammatory medicinal plants on leukocyte and platelet functions.

The enzymes 5-lipoxygenase and elastase are therapeutic targets in dermatological disorders such as psoriasis. Fifteen extracts from traditional Chinese medicinal plants used to treat topical inflammations were screened for their inhibitory effect on lipoxygenase, cyclooxygenase and elastase activity in intact leukocytes and platelets. Astragalus membranaceus, Forsythia suspensa and Poria cocos inhibited 5-lipoxygenase, with IC50 values of 141, 80 and 141 microg mL(-1), respectively. The latter two species, along with Angelica dahurica and Angelica pubescens, also inhibited elastase (IC50 values of 80, 123, 68 and 93 microg mL(-1), respectively), while A. pubescens, Atractylodes macrocephala, Lentinus edodes, Rehmannia glutinosa and Paeonia lactiflora selectively inhibited 12-(S)-HHTrE production, a valid marker of cyclooxygenase activity. The inhibition of phospholipase A(2) activity by P. cocos is discussed. Dehydrotumulosic and pachymic acids, which have been isolated from P. cocos, were shown to inhibit leukotriene B(4) release. The results indicate that both P. cocos and F. suspensa are potentially valuable species in the management of skin pathologies involving chronic inflammation.

Pharmacological approach to the pro- and anti-inflammatory effects of Ranunculus sceleratus L.

Ranunculus sceleratus is a widespread species with unique toxicological and pharmacological activities. The present study seeks to assess this species' ability, both in vitro and in vivo, to modulate processes involved in inflammations. To this end, different extracts from the aerial parts of the plant were tested in several models of acute inflammation induced by tetradecanoylphorbol acetate (TPA), arachidonic acid (AA), and carrageenan, as well as in two models of delayed hypersensitivity induced by oxazolone and dinitrofluorobencene (DNFB). The extracts were also assayed in models of eicosanoid and elastase release by intact cells. When tested in vivo, all of the extracts showed anti-inflammatory or neutral effects. In vitro, non-polar extracts of this species were able to inhibit eicosanoid production, whereas polar extracts enhanced the synthesis of 5(S)-HETE, LTB(4) and 12(S)-HHTrE. The hypothesis of a "counter-irritant" mechanism of action has thus been proposed and is also discussed herein.

New acetophenone glucosides isolated from extracts of Helichrysum italicum with antiinflammatory activity.

Three new acetophenone glucosides (4-6), three known aglycons (1-3), and a benzo-gamma-pyrone glucoside (7) were isolated from the CH(2)Cl(2), EtOAc, and BuOH extracts from the aerial parts of Helichrysum italicum. All the compounds tested showed antiinflammatory activity in a 12-O-tetradecanoylphorbol 13-acetate (TPA)-induced mouse ear edema test, and the ID(50) value of compound 2, the most active compound, was determined.

Topical anti-inflammatory activity of some Asian medicinal plants used in dermatological disorders.

The topical anti-inflammatory activity of extracts from Cassia angustifolia, Rheum palmatum, Coptis chinensis, Phellodendron amurense and Scutellaria baicalensis, plants used in traditional East Asian medicine against different skin disorders, was studied. Though in different degree, all the extracts significantly inhibited the edema induced by 12-O-tetradecanoylphorbol-13-acetate (TPA), in both single or multiple application, oxazolone, and arachidonic acid (AA). None of the extracts inhibited in vitro the activity of phospholipase A(2) (PLA(2)) from Naja naja.

In vivo anti-inflammatory activity of saponins from Bupleurum rotundifolium.

Seven oleanane-type triterpene saponins were isolated from the methanolic extract of the aerial parts of Bupleurum rotundifolium. They were identified on the basis of their spectral data as 3-O-[alpha-L-rhamnopyranosyl (1-->2)-beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl]-28-O-[beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl] echinocystic acid (saponin 1), 3-O-[alpha-L-rhamnopyranosyl (1-->2)-beta-D-glucopyranosyl (1-->2)-beta-D-fucopyranosyl] 11-methoxy-primulagenin A (saponin 2), rotundioside E (saponin 3), rotundioside F (saponin 4), 3beta-sulfate, 28-O-[beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl] ester of primulagenin A (saponin 5), rotundioside C (saponin 6) and 3-O-[alpha-L-rhamnopyranosyl (1-->2)-beta-D-glucopyranosyl (1-->2)-beta-D-fucopyranosyl] 11-methoxy-16beta,21alpha,28-trihydroxyolean-12-ene (saponin 7). All these saponins proved to be effective against TPA-induced ear edema in mice. Their ID50 were determined to be 248, 288, 128, 99 and 297 nmol/ear for saponin 1, 2, 3, 4 and 6, respectively. Saponins 3 and 6 were also active on a TPA multiple-dose model of skin chronic inflammation.