Protective effect of Myrsine parvifolia plant extract against the inflammatory process induced by Bothrops jararaca snake venom.

Accidents involving snakes from the genus Bothrops sp. constitute the most important cause of snake envenomation in Brazil. The Myrsine genus has been reported to be used in folk medicine against snakebites. In this work, the phytochemical profiles and ability of extracts from Myrsine parvifolia leaves to reduce the inflammatory process (edema, vascular permeability increase and leukocyte migration) induced by Bothrops jararaca venom were investigated in vivo. Chemical compounds were identified by chromatographic and spectroscopy techniques. Total polyphenol, tannin, and flavonoid contents were determined by spectrophotometric methods. Swiss male mice received an oral administration of extracts (100 mg/kg) in different protocols. Paw edema, intraperitoneal vascular permeability and pleurisy models in mice were used to evaluate the antiophidic potential of the extracts. Paw edema was induced by subplantar injection of B. jararaca venom and quantified as the increase in paw volume. Changes in vascular permeability were assessed by measuring the amount of Evans blue dye extravasation. Leukocyte migration was assessed by total and differential counts in the pleural cavity washes. Myricetin, myricetin-3-O-ß-arabinopyranoside, quercetin and kaempferol were isolated from the ethyl acetate extract and identified as the primary compounds of the dichloromethane extract. Terpenes and fatty acids were identified in the hexane and dichloromethane extracts. The pretreated group with hydroethanolic and dichloromethane extract reduced total edema (40 and 52%, respectively), vascular permeability increase (32.4 and 32.2%, respectively) and leukocyte influx into the pleural cavity (42 and 39%, respectively), while the group treated with hexane extract showed only reduced edema (37%) induced by B. jararaca venom. The hydroethanolic extract showed better results in all of the tests performed and was also administered by the protocol of post-poisoning, showing maintenance of paw edema reduction and cell migration. These data indicate a potential anti-inflammatory activity of M. parvifolia in poisoning by B. jararaca, especially to reduce local poison effects.

Polymeric Caffeic Acid Is a Safer Mucosal Adjuvant That Augments Antigen-Specific Mucosal and Systemic Immune Responses in Mice.

Infections remain a major threat to human lives. To overcome the threat caused by pathogens, mucosal vaccines are considered a promising strategy. However, no inactivated and/or subunit mucosal vaccine has been approved for human use, largely because of the lack of a safe and effective mucosal adjuvant. Here, we show that enzymatically synthesized polymeric caffeic acid (pCA) can act as a potent mucosal adjuvant in mice. Intranasal administration of ovalbumin (OVA) in combination with pCA resulted in the induction of OVA-specific mucosal IgA and serum IgG, especially IgG1. Importantly, pCA was synthesized from caffeic acid and horseradish peroxidase from coffee beans and horseradish, respectively, which are commonly consumed. Therefore, pCA is believed to be a highly safe material. In fact, administration of pCA did not show distinct toxicity in mice. These data indicate that pCA has merit for use as a mucosal adjuvant for nasal vaccine formulations.

Immunostimulatory effects of the standardized extract of Tinospora crispa on innate immune responses in Wistar Kyoto rats.

Tinospora crispa (TC) has been used in folkloric medicine for the treatment of various diseases and has been reported for several pharmacological activities. However, the effects of TC extract on the immune system are largely unknown. Therefore, the present study was aimed to investigate the immunomodulatory effects of a standardized 80% ethanol extract of the stem of TC on innate immune responses. Male Wistar Kyoto rats were treated daily at 100 mg/kg, 200 mg/kg, and 400 mg/kg doses of the extract for 21 days by oral gavage. The immunomodulatory potential of TC was evaluated by determining its effect on chemotaxis and phagocytic activity of neutrophils isolated from the blood of rats. To further elucidate the mechanism of action, its effects on the proliferation of T- and B-lymphocytes and T-lymphocytes subsets (CD4+ and CD8+) and on the secretion of Th1 and Th2 cytokines were also monitored. The main components of the extracts, syringin and magnoflorine, were identified and quantitatively analyzed in the extracts by using a validated reversed-phase high-performance liquid chromatography method. It was observed that the chemotactic activity of neutrophils obtained from extract-treated rats increased as compared to controls. A dose-dependent increase in the number of migrated cells and phagocytosis activity of neutrophils was observed. Dose-dependent increase was also observed in the T- and B-lymphocytes proliferation stimulated with concanavalin A (5 µg/mL) and lipopolysaccharide (10 µg/mL), and was statistically significant at 400 mg/kg (P>0.01). Apart from cell-mediated immune response, the concentrations of Th1 (TNF-α, IL-2, and IFN-γ) and Th2 (IL-4) cytokines were significantly increased in sera of rats treated with different doses as compared with the control group. From these findings, it can be concluded that TC possesses immunostimulatory activity and has therapeutic potential for the prevention of immune diseases.

N-acetylcysteine advancement of surfactant therapy in experimental meconium aspiration syndrome: possible mechanisms.

Meconium aspiration syndrome (MAS) is meconium-induced respiratory failure of newborns associated with activation of inflammatory and oxidative pathways. For severe MAS, exogenous surfactant treatment is used which improves respiratory functions but does not treat the inflammation. Oxidative process can lead to later surfactant inactivation; hence, surfactant combination with antioxidative agent may enhance the therapeutic effect. Young New Zealand rabbits were instilled by meconium suspension and treated by surfactant alone, N-acetylcysteine (NAC) alone or by their combination and oxygen-ventilated for 5 h. Blood samples were taken before and 30 min after meconium application and 30 min, 1, 3 and 5 h after the treatment for evaluating of oxidative damage, total leukocyte count, leukocyte differential count and respiratory parameters. Leukocyte differential was assessed also in bronchoalveolar lavage fluid. NAC alone had only mild therapeutic effect on MAS. However, the combination of NAC and surfactant facilitated rapid onset of therapeutic effect in respiratory parameters (oxygenation index, PaO(2)/FiO(2)) compared to surfactant alone and was the only treatment which prevented neutrophil migration into the lungs, oxidative damage and lung edema. Moreover, NAC suppressed IL-8 and IL-beta formation and thus seems to be favorable agent for improving surfactant therapy in MAS.

Optimization and pharmacological validation of a leukocyte migration assay in zebrafish larvae for the rapid in vivo bioactivity analysis of anti-inflammatory secondary metabolites.

Over the past decade, zebrafish (Danio rerio) have emerged as an attractive model for in vivo drug discovery. In this study, we explore the suitability of zebrafish larvae to rapidly evaluate the anti-inflammatory activity of natural products (NPs) and medicinal plants used in traditional medicine for the treatment of inflammatory disorders. First, we optimized a zebrafish assay for leukocyte migration. Inflammation was induced in four days post-fertilization (dpf) zebrafish larvae by tail transection and co-incubation with bacterial lipopolysaccharides (LPS), resulting in a robust recruitment of leukocytes to the zone of injury. Migrating zebrafish leukocytes were detected in situ by myeloperoxidase (MPO) staining, and anti-inflammatory activity was semi-quantitatively scored using a standardized scale of relative leukocyte migration (RLM). Pharmacological validation of this optimized assay was performed with a panel of anti-inflammatory drugs, demonstrating a concentration-responsive inhibition of leukocyte migration for both steroidal and non-steroidal anti-inflammatory drugs (SAIDs and NSAIDs). Subsequently, we evaluated the bioactivity of structurally diverse NPs with well-documented anti-inflammatory properties. Finally, we further used this zebrafish-based assay to quantify the anti-inflammatory activity in the aqueous and methanolic extracts of several medicinal plants. Our results indicate the suitability of this LPS-enhanced leukocyte migration assay in zebrafish larvae as a front-line screening platform in NP discovery, including for the bioassay-guided isolation of anti-inflammatory secondary metabolites from complex NP extracts.

Anti-inflammatory activity of Ocimum americanum L. essential oil in experimental model of zymosan-induced arthritis.

Essential oils are potential sources of novel components for medicinal use. The present study was performed to investigate the composition and anti-inflammatory activity of Ocimum americanum L. essential oil (OEO) and its components in an experimental model of zymosan-induced arthritis and paw edema. The essential oil was obtained by hydro-distillation and analyzed by gas chromatography-mass spectrometry. Twenty-six components, representing 98.9% of the total oil, were characterized, with linalool (19.63%) and 1,8-cineole (17.27%) as the main components. The OEO and its two constituents inhibited leukocyte influx into the synovial space and reduced paw edema induced by zymosan. The OEO also inhibited interferon-γ levels but did not reduce transforming growth factor-ß levels. Additionally, the OEO protected against leukocyte influx into the synovial membrane and cartilage destruction in knee joints in arthritic mice. These findings indicate that the essential oil of Ocimum americanum L. exerted significant anti-inflammatory effects, likely related to its main compounds.

Compound A, a dissociated glucocorticoid receptor modulator, reduces dengue virus-induced cytokine secretion and dengue virus production.

Dengue Virus (DENV) infection is an important mosquito-borne viral disease and its clinical symptoms range from a predominantly febrile disease, dengue fever (DF), to dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Increased levels of cytokines - the so-called 'cytokine storm', contribute to the pathogenesis of DHF/DSS. In this study, we compared the expression of cytokine genes between mock-infected and DENV-infected HepG2 cells using a real-time PCR array and revealed several up-regulated chemokines and cytokines, including CXCL10 and TNF-α. Compound A (CpdA), a plant-derived phenyl aziridine precursor containing anti-inflammatory action and acting as a dissociated nonsteroidal glucocorticoid receptor modulator, was selected as a candidate agent to modulate secretion of DENV-induced cytokines. CpdA is not a glucocorticoid but has an anti-inflammatory effect with no metabolic side effects as steroidal ligands. CpdA significantly reduced DENV-induced CXCL10 and TNF-α secretion and decreased leukocyte migration indicating for the first time the therapeutic potential of CpdA in decreasing massive immune activation during DENV infection.

Anti-inflammatory activity of ethanol extract and fractions from Couroupita guianensis Aublet leaves.

ETHNOPHARMACOLOGICAL RELEVANCE: Couroupita guianensis Aublet, 'macacarecuia', 'abricó-de-macaco', 'castanha-de-macaco' and 'amêndoa-dos-andes', is found in tropical regions and is widely used in the treatment of tumors, pain, and inflammatory processes. AIM OF THE STUDY: Ethanol extract and hexane and ethyl acetate fractions were evaluated in models of inflammatory pain (formalin-induced licking) and acute inflammation (carrageenan-induced peritonitis). MATERIALS AND METHODS: Ethanol extract, hexane and ethyl acetate fractions (10, 30 or 100 mg/kg, p.o.) and the reference drugs dexamethasone (5 mg/kg), morphine (5 mg/kg, s.c.), and acetylsalicylic acid (100 mg/kg, p.o.) were tested in formalin-induced licking response and carrageenan-induced peritonitis. RESULTS: All three doses from Couroupita guianensis fractions significantly reduced the time that the animal spent licking the formalin-injected paw in first and second phases. However, only higher doses (30 and 100 mg/kg) were able to inhibit the leukocyte migration into the peritoneal cavity after carrageenan injection. In this model, the 100 mg/kg dose almost abolished the cell migration. It was also observed that protein concentration resulted from extravasation to the peritoneum and nitric oxide (NO) productions were significantly reduced. Cytokines production was differently affected by the treatment. TNF-α production was reduced after ethanol extract and ethyl acetate fraction pre-treatment whereas hexane fraction had effect only with 100 mg/kg dose. IL-1ß production was inhibited only after hexane fraction pre-treatment. The inhibitory effect observed was not due to a direct cytotoxic effect on cells nor to a NO-scavenger activity. The effect was due to a direct inhibition on NO production by the cells. CONCLUSIONS: The results show that Couroupita guianensis fractions have anti-inflammatory effect, partly due to a reduction on cell migration and a inhibition on cytokines and inflammatory mediators production.

Anti-inflammatory and cicatrizing activities of thymol, a monoterpene of the essential oil from Lippia gracilis, in rodents.

ETHNOPHARMACOLOGICAL RELEVANCE: Lippia gracilis Schauer (Verbenaceae) has long been recognized in folk medicine as a medicinal plant. The essential oil of Lippia gracilis has antimicrobial activity and is used externally to treat cutaneous diseases, burns, wounds, and ulcers. Recently, our research group demonstrated that the essential oil of Lippia gracilis leaves possesses antinociceptive and anti-inflammatory actions and its major component identified was thymol. The objective of this study was to assess the anti-inflammatory and wound healing activities of thymol in rodents. MATERIALS AND METHODS: For the anti-inflammatory analysis the paw oedema and peritonitis models were used, followed by the assessment of the mieloperoxidase (MPO) activity, total cell counting, and histological analysis. The animals were treated (i.p., n=6/group) with thymol (10, 30, and 100 mg/kg), dexamethasone (2 mg/kg), or vehicle (1% Tween 80). In order to assess the wound healing potential, thymol was vehiculated into collagen-based dressing films and a biological wound healing test was conducted. The retraction index of the wounds and histological analysis were performed on the 3rd, 7th, 14th, and 21th days, split into three groups: undressed wounds (CTR), dressed with collagen-based films (COL), and dressed with collagen-based containing thymol (COLTHY) films. RESULTS: Thymol reduced significantly the oedema (100 mg/kg, P<0.001) and, besides, diminished the influx of leukocytes to the injured area (10, 30, and 100 mg/kg), according to the assessment of MPO activity (P<0.001), total cell count (P<0.05), and histological analysis. Wounds dressed with COLTHY films showed significantly bigger wound retraction rates (7 and 14 day, P<0.05) and improved the granulation reaction, as well provided better collagenization density and arrangement during wound healing. CONCLUSIONS: This study suggests that thymol is a promising compound to be used in treatment of inflammatory processes as well as wound healing. The pharmacological actions of Lippia gracilis in popular medicine practices may be related, at least in part, to the presence of thymol in the essential oil.

Rosmarinus officinalis L. essential oil inhibits in vivo and in vitro leukocyte migration.

Rosmarinus officinalis L. (Lamiaceae), popularly known as rosemary, is used for food flavoring and in folk medicine as an antispasmodic, analgesic, antirheumatic, diuretic, and antiepileptic agent. Few studies have shown the anti-inflammatory effects of rosemary essential oil (REO). This study evaluated the effects of REO on leukocyte migration through in vivo leukocyte migration and in vitro chemotaxis assay. REO was analyzed by using gas chromatography-mass spectometry, and the main components identified were camphor (27.59%), 1,8-cineole (15.74%), α-pinene (16.58%), and ß-myrcene (10.02%). In rats, administration of REO reduced the number of leukocytes that rolled, adhered, and migrated to the scrotal chamber after carrageenan injection. All doses of REO tested significantly inhibited leukocyte chemotaxis induced by casein. The effects of REO on leukocyte migration highlight an important mechanism of the anti-inflammatory action of rosemary.

The effect of montelukast in a model of gouty arthritis induced by sodium monourate crystals.

Non-steroidal anti-inflammatory drugs (NSAIDS) are the first line of therapy in acute gouty arthritis. NSAIDs inhibit the cyclooxygenase pathway, but not the lipooxygenase activity and can have many adverse effects and thus have a limited effect on the control of inflammation in this disease. In this work we studied the effect of montelukast on the cellular inflammatory infiltrate in a model of murine arthritis induced by sodium monourate crystals (SMU), using a subcutaneous air cavity (air pouch) in BALB/c mice. Seven groups of BALB/c mice (n = 4) were distributed into five experimental groups and two inflammatory control groups, a positive and a negative one. Previous to SMU exposure, the experimental groups received montelukast (1 and 0.01 mg/Kg/w) and/or indomethacine (2.5 mg/Kg/w), followed by administration of SMU in the air pouch. The total and differential counts of inflammatory cells were analyzed after 2, 6, 12 and 24 hours. Montelukast, significantly reduced the total number of cells (p < 0.05), with a predominant impact on polymorphonuclear over mononuclear cells, especially after 12 hours of the medication. The montelukast/indometacine combination showed an additive effect. Our data show that montelukast has an anti-inflammatory effect in the model of gouty arthritis. Consequently, anti-leukotrienes could represent a new and effective therapy, either isolated or combined with conventional therapy of gouty arthritis.

The effect of montelukast in a model of gouty arthritis induced by sodium monourate crystals / Efecto de montelukast en un modelo de artritis gotosa inducido por cristales de monourato de sodio

Non-steroidal anti-inflammatory drugs (NSAIDS) are the first line of therapy in acute gouty arthritis. NSAIDs inhibit the cyclooxygenase pathway, but not the lipooxygenase activity and can have many adverse effects and thus have a limited effect on the control of inflammation in this disease. In this work we studied the effect of montelukast on the cellular inflammatory infiltrate in a model of murine arthritis induced by sodium monourate crystals (SMU), using a subcutaneous air cavity (air pouch) in BALB/c mice. Seven groups of BALB/c mice (n = 4) were distributed into five experimental groups and two inflammatory control groups, a positive and a negative one. Previous to SMU exposure, the experimental groups received montelukast (1 and 0.01 mg/Kg/w) and/or indomethacine (2.5 mg/Kg/w), followed by administration of SMU in the air pouch. The total and differential counts of inflammatory cells were analyzed after 2, 6, 12 and 24 hours. Montelukast, significantly reduced the total number of cells (p<0.05), with a predominant impact on polymorphonuclear over mononuclear cells, especially after 12 hours of the medication. The montelukast/indometacine combination showed an additive effect. Our data show that montelukast has an anti-inflammatory effect in the model of gouty arthritis. Consequently, anti-leukotrienes could represent a new and effective therapy, either isolated or combined with conventional therapy of gouty arthritis.

En artritis gotosa aguda las drogas antiinflamatorias no esteroideas son la primera línea terapéutica. Este tratamiento no es satisfactorio porque inhibe la ciclooxigenasa sin modificar la actividad de la lipooxigenasa, y puede acompañarse de numerosos efectos adversos. Investigamos el efecto de montelukast sobre el infiltrado celular inflamatorio en un modelo de artritis múrida inducida por cristales de monourato de sodio (MUS) en el modelo experimental de la bolsa de aire (air pouch). Siete grupos de ratones BALB/c (n = 4) fueron distribuidos en cinco grupos experimentales y dos grupos controles inflamatorios: positivo y negativo. Los grupos experimentales recibieron, montelukast (1 y 0,01 mg/Kg/p) y/o indometacina (2,5 mg/Kg/p) por vía oral, previo a la administración de MUS en la bolsa del aire. El conteo absoluto y diferencial de las células inflamatorias fue analizado después de 2, 6, 12 y 24 horas de tratamiento. El tratamiento con montelukast redujo significativamente el número total de células presentes en el infiltrado inflamatorio (p < 0,05), con un efecto mayor sobre polimorfonucleares que sobre las células mononucleares, y con un máximo efecto a las 12 horas después de la administración del medicamento. La combinación montelukast/indometacina mostró un efecto aditivo. Los resultados demuestran que montelukast tiene un efecto antiinflamatorio en el modelo de la artritis gotosa. Por lo tanto, los anti-leucotrienos podrían representar una nueva y eficaz terapia, aislada o en combinación con la terapéutica convencional, para la artritis gotosa.

Effects of Himatanthus lancifolius on human leukocyte chemotaxis and their adhesion to integrins.

The aim of this work was to investigate the anti-inflammatory activities of the uleine-rich fraction extracted from the barks of Himatanthus lancifolius (Muell. Arg.) Woodson (Apocynaceae). To achieve this, we focused on its in vitro effects on some steps of the inflammatory response using peripheral human leukocytes. The results presented herein show that the uleine-rich fraction significantly inhibits the migration of casein-induced granulocytes and their adhesion to fibronectin and vitronectin, along with mononuclear cells, by down-regulating the expression of alpha 4beta1 and alpha5beta1 integrins. The data suggest that H. LANCIFOLIUS has the potential of interferring with leukocyte trafficking through its uleine-rich fraction, emphasizing its usefulness in inflammatory conditions. DEXA:dexamethasone disodium phosphate FN:fibronectin PMN:polymorphonuclear URF:uleine-rich fraction VN:vitronectin.

Antinociceptive and anti-inflammatory activities of Aquilaria sinensis (Lour.) Gilg. Leaves extract.

AIM OF THE STUDY: The analgesic and anti-inflammatory activities of the ethanol extract of Aquilaria sinensis (Lour.) Gilg. Leaves were observed in various experimental models related to nociception and inflammation, so as to provide some evidence for its traditional use. MATERIALS AND METHODS: Acetic acid-induced writhing and a hot plate test in mice were used to evaluate its analgesic activity. On the other hand, its anti-inflammatory activity was observed in xylene or carrageenan-induced edema, carboxymethylcellulose sodium (CMC-Na)-induced leukocyte migration in mice and lipopolysaccharide (LPS)-induced nitric oxide (NO) release from mouse peritoneal macrophages in vitro. RESULTS: The ethanol extract significantly inhibited acetic acid-induced writhing after single oral administration at doses of 424 and 848 mg extract/kg, and the response to the thermal stimulus in mice at the dose of 848 mg/kg. Meanwhile, the ethanol extract also remarkably lessened xylene-induced ear swelling, carrageenan-induced paw edema, and CMC-Na-induced leukocyte migration. Furthermore, the extract considerably reduced NO release from LPS-stimulated macrophages with IC50 of 80.4 mg/ml. CONCLUSION: These findings suggest that Aquilaria sinensis (Lour.) Gilg. Leaves extract present notable analgesic and anti-inflammatory activities, which support its folkloric use for some diseases related with painful and inflammatory conditions such as trauma etc.