Antibacterial, antibiofilm, and antivirulence potential of the main diterpenes from Copaifera spp. oleoresins against multidrug-resistant bacteria.

To evaluate the antibacterial, antibiofilm and antivirulence potential of the main diterpenes from Copaifera spp. oleoresins against multidrug-resistant (MDR) bacteria. Antimicrobial assays included determination of the Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC), Minimum Inhibitory Concentration of Biofilm (MICB50), as well as synergistic and antivirulence assays for eight diterpenes against MDR. The tests revealed that two diterpenes (named 1 and 5) showed the best results, with MIC and MBC between 12.5 and 50 µg/mL against most MDR bacteria. These diterpenes exhibited promising MICB50 in concentration between 3.12-25 µg/mL but showed no synergistic antimicrobial activity. In the assessment of antivirulence activity, diterpenes 1 and 5 inhibited only one of the virulence factors evaluated (Dnase) produced by some strains of S. aureus at subinhibitory concentration (6.25 µg/mL). Results obtained indicated that diterpenes isolated from Copaifera oleoresin plays an important part in the search of new antibacterial and antibiofilm agents that can act against MDR bacteria.

Biosynthesis and characterization of gold nanoparticles using Brazilian red propolis and evaluation of its antimicrobial and anticancer activities.

Gold nanoparticles (AuNPs) are highlighted due to their low toxicity, compatibility with the human body, high surface area to volume ratio, and surfaces that can be easily modified with ligands. Biosynthesis of AuNPs using plant extract is considered a simple, low-cost, and eco-friendly approach. Brazilian Red Propolis (BRP), a product of bees, exhibits anti-inflammatory, anti-tumor, antioxidant, and antimicrobial activities. Here, we described the biosynthesis of AuNPs using BRP extract (AuNPextract) and its fractions (AuNPhexane, AuNPdichloromethane, AuNPethyl acetate) and evaluated their structural properties and their potential against microorganisms and cancer cells. AuNPs showed a surface plasmon resonance (SPR) band at 535 nm. The sizes and morphologies were influenced by the BRP sample used in the reaction. FTIR and TGA revealed the involvement of bioactive compounds from BRP extract or its fractions in the synthesis and stabilization of AuNPs. AuNPdichloromethane and AuNPhexane exhibited antimicrobial activities against all strains tested, showing their efficacy as antimicrobial agents to treat infectious diseases. AuNPs showed dose-dependent cytotoxic activity both in T24 and PC-3 cells. AuNPdichloromethane and AuNPextract exhibited the highest in vitro cytotoxic effect. Also, the cytotoxicity of biogenic nanoparticles was induced by mechanisms associated with apoptosis. The results highlight a potential low-cost green method using Brazilian red propolis to synthesize AuNPs, which demonstrated significant biological properties.

Targeted uptake of folic acid-functionalized polymeric nanoparticles loading glycoalkaloidic extract in vitro and in vivo assays.

Solanum lycocarpum fruits contain two major glycoalkaloids (GAs), solamargine (SM) and solasonine (SS). These compounds are reported as cytotoxic. However, they have poor water solubility and low bioavailability. To overcome these disadvantages and getting an efficient formulation the current study aimed to develop, characterize, and test the effectiveness of a nanotechnology-based strategy using poly(D,L-lactide) (PLA) nanoparticles functionalized with folate as delivery system of glycoalkaloidic extract (AE) for bladder cancer therapy. The strategic of adding folic acid into nanoformulations can increase the selectivity of the compounds to the cancer cells reducing the side effects. Our results revealed the successful preparation of AE-loaded folate-targeted nanoparticles (NP-F-AE) with particle size around 177 nm, negative zeta potential, polydispersity index <0.20, and higher efficiency of encapsulation for both GAs present in the extract (>85 %). To investigate the cellular uptake, the fluorescent dye coumarin-6 was encapsulated into the nanoparticle (NP-F-C6). The cell studies showed high uptake of nanoparticles by breast (MDA-MB-231) and bladder (RT4) cancer cells, but not for normal keratinocytes cells (HaCaT) indicating the target uptake to cancer cells. The cytotoxicity of nanoparticles was evaluated on RT4 2D culture model showing 2.16-fold lower IC50 than the free AE. Furthermore, the IC50 increased on the RT4 spheroids compared to 2D model. The nanoparticles penetrated homogeneously into the urotheliumof porcine bladder. These results showed that folate-conjugated polymeric nanoparticles are potential carriers for targeted glycoalkaloidic extract delivery to bladder cancer cells.

Isolation and characterization of 2-pyridone alkaloids and alloxazines from Beauveria bassiana.

Two novel compounds bearing heterocyclic nitrogen, 2-pyridone alkaloid (1) and alloxazine derivative (2), along with the known pretenellin B (3), pyridovericin (4) and lumichrome (5) were isolated from a culture of the entomopathogenic fungal strain Beauveria bassiana. The chemical structures of 2-pyridone alkaloid and alloxazine derivative were established on the basis of the interpretation of spectroscopic data. The isolated compounds were evaluated in a panel of five cancer cell lines and pyridovericin exhibited cytotoxicity (IC50, µM) against cancer cell lines: HL-60 (25.9 ± 0.3), HCT8 (34.6 ± 3.6), MDA-MB435 (34.8 ± 3.8) and SF295 (31.1 ± 0.6). Considering that other pyridone compounds display good cytotoxic activity, it would be suggested to obtain new semi synthetic derivatives of pyridovericin, for the development of new cytotoxic chemical entities.

A New Antileishmanial Preparation of Combined Solamargine and Solasonine Heals Cutaneous Leishmaniasis through Different Immunochemical Pathways.

Little has been done during the past 100 years to develop new antileishmanial drugs. Most infected individuals live in poor countries and have a low cash income to be attractive targets to pharmaceutical corporations. Two heterosidic steroids, solamargine and solasonine, initially identified as major components of the Brazilian plant Solanum lycocarpum, were tested for leishmanicidal activity. Both alkaloids killed intracellular and extracellular Leishmania mexicana parasites more efficiently than the reference drug sodium stibogluconate. A total of 10 µM each individual alkaloid significantly reduced parasite counts in infected macrophages and dendritic cells. In vivo treatment of C57BL/6 mice with a standardized topical preparation containing solamargine (45.1%) and solasonine (44.4%) gave significant reductions in lesion sizes and parasite counts recovered from lesions. Alkaloids present different immunochemical pathways in macrophages and dendritic cells. We conclude that this topical preparation is effective and a potential new and inexpensive treatment for cutaneous leishmaniasis.

Immunomodulatory/anti-inflammatory effects of Baccharis dracunculifolia leaves.

A possible immunomodulatory/anti-inflammatory effect of Baccharis dracunculifolia (Bd) and its major compound--caffeic acid (Ca)--on cytokines production (IL-1ß, IL-6 and IL-10) by murine macrophages was investigated. Cells were incubated with Bd and Ca, and the inhibitory concentrations were tested before or after macrophages challenge with LPS. Bd and Ca stimulated IL-1ß and inhibited IL-6 and IL-10 production. In LPS-challenge protocols, Bd prevented LPS action either before or after LPS challenge, whereas Ca prevented LPS effects only after LPS addition. Bd modulatory action on cytokines production may be at least in part mediated by Ca, since it has been shown to inhibit the transcription factor NF-κB. Further studies are still needed to evaluate Bd efficacy in inflammatory diseases, in order to explore its antiinflammatory activity in vivo.

Δ-lactam derivative from thermophilic soil fungus exhibits in vitro anti-allergic activity.

From cultures of thermophilic soil fungus Humicola grisea var thermoidea, a δ-lactam derivative (3-(2-(4-hydroxyphenyl)-2-oxoethyl)-5,6-dihydropyridin-2(1H)-one) that displayed anti-allergic activity was isolated, which was predicted by in silico computational chemistry approaches. The in vitro anti-allergic activity was investigated by ß-hexosaminidase release assay in rat basophilic leukaemia RBL-2H3 cells. The δ-lactam derivative exhibited similar anti-allergic activity (IC(50) = 18.7 ± 6.7 µM) in comparison with ketotifen fumarate (IC(50) = 15.0 ± 1.3 µM) and stronger anti-allergic activity than azelastine (IC(50) = 32.0 µM). Also, the MTT cytotoxicity assay with RBL-2H3 cells showed that δ-lactam does not display cytotoxicity at concentrations lower than 50 µM. This study suggests that the δ-lactam derivative has the potential to be used as a lead compound in the development of anti-allergic drugs for clinical use in humans.

In vitro cytotoxic activity of Baccharis dracunculifolia and propolis against HEp-2 cells.

Baccharis dracunculifolia is the most important vegetal source of propolis in southeast Brazil, and researchers have been investigating its biological properties. Propolis is a complex resinous hive product collected by bees from several plants, showing a very complex chemical composition. It has been employed since ancient times due to its therapeutic properties, such as antimicrobial, anti-inflammatory, antioxidant, immunomodulatory and antitumour activities, among others. The goal of this work was to compare the cytotoxic action of B. dracunculifolia, propolis and two isolated compounds (caffeic and cinnamic acids) on human laryngeal epidermoid carcinoma (HEp-2) cells in vitro. These cells were incubated with different concentrations of each variable, and cell viability was assessed by the crystal violet method. Lower concentrations of B. dracunculifolia (extract and essential oil), propolis, as well as caffeic and cinnamic acids, showed no cytotoxic activity against HEp-2 cells. On the other hand, elevated concentrations (50 and 100 µg per 100 µL) exerted a cytotoxic action, and propolis showed a more efficient action than its vegetal source and isolated compounds. Further investigation is still needed in order to explore the potential of these variables as antitumour agents and to understand their mechanisms of action.

Lemongrass effects on IL-1beta and IL-6 production by macrophages.

Cymbopogon citratus has been widely recognised for its ethnobotanical and medicinal usefulness. Its insecticidal, antimicrobial and therapeutic properties have been reported, but little is known about its effect on the immune system. This work aimed to investigate the in vivo effect of a water extract of lemongrass on pro-inflammatory cytokine (IL-1beta and IL-6) production by macrophages of BALB/c mice. The action of lemongrass essential oil on cytokine production by macrophages was also analysed in vitro. The chemical composition of the extract and the oil was also investigated. Treatment of mice with water extract of lemongrass inhibited macrophages to produce IL-1beta but induced IL-6 production by these cells. Lemongrass essential oil inhibited the cytokine production in vitro. Linalool oxide and epoxy-linalool oxide were found to be the major components of lemongrass water extract, and neral and geranial were the major compounds of its essential oil. Taken together, these data suggest an anti-inflammatory action of this natural product.

Anti-poliovirus activity of Baccharis dracunculifolia and propolis by cell viability determination and real-time PCR.

AIMS: The aim of this work was to evaluate the antiviral activities of Baccharis dracunculifolia (extract and essential oil), propolis and some isolated compounds (caffeic and cinnamic acids) against poliovirus type 1 (PV1) replication in HEp-2 cells. METHOD: Three different protocols (pre-, simultaneous and post-treatments) were used to verify the effect of addition time of the variables on PV1 replication by crystal violet method and relative viral RNA quantification by real-time PCR for analysing in which step of virus replication the variables could interfere. CONCLUSIONS: Data revealed that the B. dracunculifolia showed the best antiviral activity percentage in the simultaneous treatment, as well as lower relative viral quantification by real-time PCR. Variables might block partially the viral entry within cells, affect the steps of viral cycle replication into cells, or lead to RNA degradation before the virus entry into cells or after their release to the supernatant. SIGNIFICANCE AND IMPACT OF THE STUDY: Baccharis dracunculifolia is the most important botanical source of the south-eastern Brazilian propolis, and its potential for the development of new phytotherapeutic medicines has been investigated. Propolis is commonly used for its antimicrobial and immunomodulatory activities. Nevertheless, B. dracunculifolia and propolis effects on PV1 have not been investigated yet.

In vitro and in vivo effects of clove on pro-inflammatory cytokines production by macrophages.

Biological properties of clove have been reported, but little is known about its effect on the immune system. This work was aimed to investigate the effect in vivo of a water-soluble part of hydroalcoholic extract of clove on pro-inflammatory cytokines (IL-1beta and IL-6) production by macrophages of BALB/c mice. The action of the essential oil of clove on the production of these cytokines macrophages was also investigated in vitro. The chemical compositions of the extract and of the oil were also investigated. Treatment of mice with water extract of clove was found to inhibit macrophages to produce both IL-1beta and IL-6. The essential oil of clove also inhibited the production of these cytokines in vitro. Eugenol was found to be the major component of the clove extract and essential oil, and probably is the causative agent of cytokine inhibition. Taken together, these data suggest an anti-inflammatory action of this spice.

Trypanocidal structure-activity relationship for cis- and trans-methylpluviatolide.

The trypanocidal activity of racemic mixtures of cis- and trans-methylpluviatolides was evaluated in vitro against trypomastigote forms of two strains of Trypanosoma cruzi, and in the enzymatic assay of T. cruzi gGAPDH. The cytotoxicity of the compounds was assessed by the MTT method using LLC-MK2 cells. The effect of the compounds on peroxide and NO production were also investigated. The mixture of the trans stereoisomers displayed trypanocidal activity (IC50 approximately 89.3 microM). Therefore, it was separated by chiral HPLC, furnishing the (+) and (-)-enantiomers. Only the (-)-enantiomer was active against the parasite (IC50 approximately 18.7 microM). Despite being inactive, the (+)-enantiomer acted as an antagonistic competitor. Trans-methylpluviatolide displayed low toxicity for LLC-MK2 cells, with an IC50 of 6.53 mM. Furthermore, methylpluviatolide neither inhibited gGAPDH activity nor hindered peroxide and NO production at the evaluated concentrations.

Anti-inflammatory and antinociceptive activities of extract, fractions and populnoic acid from bark wood of Austroplenckia populnea.

Austroplenckia populnea (Reiss) Lund is a Brazilian plant from "cerrado", which belongs to Celastraceae family, popularity know as "marmelinho-do campo, mangabeira-brava, mangabarana, vime and maria-mole". This plant is used in folk medicine to treat dysenteries and inflammatory disorders, such as rheumatism. Austroplenckia populnea bark hydroalcoholic crude extract, and its hexane, chloroform and ethyl acetate fractions, obtained by partition, as well as the isolated populnoic acid were investigated for their anti-inflammatory (carrageenan, dextran and histamine-induced rat paw oedema, histamine-induced increase in vascular permeability, and granulomatous tissue induction) and analgesic activities (writhing and hot plate tests). The ED(50) (oral) of the crude extract for the inhibition of carragenan-induced rat paw oedema assay was determined to be 200 mg/kg, which was also used in the assays with the extract and its fractions in all other experiments. Populnoic acid was administered in the dose of 50 mg/kg. Crude extract, hexane and chloroform fractions (200 mg/kg), and indomethacin (10 mg/kg) inhibited significantly (p<0.05) the formation of the carrageenan-induced rat paw oedema, measured in third hour of experiment (peak of oedema formation) by 43.2%, 37.3%, 31.1% and 59.3%, respectively. There was a significant reduction (p<0.05) in dextran-induced rat paw oedema in all groups, while in the assay using histamine as the oedematogenic agent, only the groups treated with populnoic acid (50 mg/kg) and cyproheptadine (10 mg/kg) displayed significant reduction (p<0.05). The populnoic acid and cyproheptadine reduced the peak of oedema formation (1st hour) by 41.3% and 34.7%, respectively. Only for the groups treated with populnoic acid (50 mg/kg) and cyproheptadine (10 mg/kg) it was observed a significant (p<0.05) reduction in histamine-induced increase in vascular permeability (44.8% and 80.3%, respectively). Granulomatous tissue formation was significantly inhibited (p<0.05) by both hexane fraction (46.0%) and dexamethasone (66.2%). In the analgesic assays, the crude extract and its hexane and chloroform fractions, as well as indomethacin diminished significantly the number of writhings (p<0.05) by 69.6%, 47.2%, 44.8% and 62.8%, respectively. On the other hand, none assayed sample displayed significant result in the hot plate test. Based on the obtained results it is suggested that extracts of Austroplenckia populnea bark and populnoic acid display anti-inflammatory activity, supporting its folkloric use to treat inflammatory disorders.

Analgesic and anti-inflammatory activity of a crude root extract of Pfaffia glomerata (Spreng) Pedersen.

The anti-inflammatory and antinociceptive effects of the crude hydroalcoholic extract (PE) of Pfaffia glomerata roots was assessed in the carrageenan-induced rat paw edema at the doses of 100, 200 and 300 mg/kg, using different animal models. An anti-inflammatory dose effect response correlation of r=0.997 and Y=11.67x+0.02 was found. At the same doses, the extract-inhibited acetic acid-induced writhing in mice, but no dose response correlation was found. Oral administration of 100 mg/kg of PE and 0.5 mg/kg of dexamethazone inhibited by 29 and 61%, the granulomatous tissue formation (p>0.05), respectively. These results indicate the potential of this plant extract to treat chronic inflammation. At the assayed doses no significant activity was found in the hot plate test, as well as in the cell migration-induced by carrageenan.

Biological activity evaluation of dibenzilbutirolactones lignans derivatives against Leishmania braziliensis

This work reports the results of the in vitro assay against extracellular forms of Leishmania (viannia) braziliensis of eleven dibenzylbutyrolactone derivatives, either isolated from plants or obtained by synthesis. From these, only two showed relative biological activity against the parasite, the raceme mixtures of methylpluviatolide: IC50 = 496 mM and (-)-6,6'- dinitrocubebin: IC50 = 510,4 μM. Thus, it can be suggested that the metabolic pathway responsible for the biological activity of these compounds against this parasite genera differs from the one related to Trypanosoma cruzi, for which these compounds were quite active. This fact highly also suggests that this class of compounds is more selective against T. cruzi. Nevertheles, other lignans derivatives should be obtained to allow the fully evaluation of this class of lignans against Leishmaniosis.

Este trabalho apresenta os resultados de ensaios in vitro contra formas extracelulares de Leishmania (viannia) braziliensis de onze derivados de dibenzilbutirolactonas isolados de plantas ou obtidos através de síntese. Destes, só dois mostraram atividade biológica relativa contra o parasita, as misturas racêmicas de methilpluviatolide,: IC50 = 496 M e (-) -6,6' - dinitrocubebin: IC50 = 510,4 M. Assim, pode-se sugerir que o caminho metabólico responsável para a atividade biológica destas combinações contra estes gêneros de parasita difere do relacionado a Trypanosoma cruzi para o qual estas combinações foram bastante ativas. Este fato também sugere fortemente que essa classe de combinações é mais seletivo contra T. cruzi. Dessa forma, deveriam ser obtidos outros derivados de lignanas para permitir a completa avaliação desta classe de substâncias contra Leishmaniose.

Atividade antiinflamatória, antiúlcera gástrica e toxicidade subcrônica do extrato etanólico de própolis / Anti-inflammatory activity, gastric antiulcer and subchronic toxicity of the ethanol extract of propolis

Avaliou-se a atividade antiinflamatória do extrato etanólico de própolis - EEP, . sobre o edema desencadeado por carragenina, dextrana e histamina. O EEP apresentou dose eficaz (DE50) de 650 mg/kg (v.o), inibindo significativamente o processo inflamatório desencadeado pela carragenina, mas não inibiu o produzido por dextrana. O EEP antagonizou ainda o efeito edematogênico produzido por histamina. Nas úlceras produzidas por estresse, o EPP inibiu de forma significativa a geração dos diversos tipos classificados. Em todos os parâmetros analisados no estudo da toxicidade em fase de tratamento subcrônico , (hematológicos, bioquímicos e histopatológicos), o grupo tratado com o EEP não apresentou diferença significativa em relação ao grupo controle. Desta forma, sugere-se que na dose de 650 mg/kg (dose eficaz) não existe a presença de efeitos tóxicos que possam comprometer a utilização deste extrato.

The antlinflammatory activity of Ethanolic Extract of Propolis - EEP was evaluated on edema induced by carrageenan, dextran and hystamine. The inflammatory process induced by carrageenan was significantly reduced by the treatment with EEP (650 mg/kg, p.o), while it did not interfere in the response induced by dextran. The EEP antagonized the edematous effect produced by hystamine. The EEP promoted a significant inhibition in the generation of the ulcers induced by stress (p < 0.05). The hematological, biochemical and histopathological parameters presented no differences between treated and control groups. Therefore it can be concluded that the effective dose of 650 mg/kg of the EEP has no toxic effect which may compromise the use of this extract.

Anti-inflammatory activity of the crude extract from the fruits of Pterodon emarginatus Vog.

The vegetal species Pterodon emarginatus Vog. (Leguminosae/Papilonaceae), popularly known in Brazil as 'sucupira branca', is widely used by domestic medicine as an anti-inflammatory. From these observations, the hexanic crude extract (HCE) of the fruits was obtained and submitted for assessment of its anti-inflammatory activity. For this purpose, the following tests were used: (1) Determination of ED50 and LD50; (2) Paw edema induced by carrageenin, dextran, histamine and nystatin; (3) Peritonitis caused by carrageenin and (4) Granuloma test. The ED50 (oral) in the edema induced by carrageenin was 500 mg/kg, and LD50 (oral) was 4.02 g/kg. In the edema caused by nystatin, there was a significant inhibition by 45% (P < 0.05 student's t-test) at the 6th hour following the treatment. In the granuloma test performed in animals treated with HCE, there was an inhibition of the granulomatous tissue formation by 22%. The migration of neutrophils towards the peritoneal cavity was inhibited in HCE treated animals by 43% (P < 0.05). However, in the edema caused by dextran and histamine, there was no significant response in HCE treated animals.

Valores de DL50 em peixes e no rato tratados com pó de raízes de Derris spp e suas implicações ecotoxicológicas / LD50 in fish and rat produced by powdered roots of Derris spp and ecotoxicological implications

Os "timbós verdadeiros" (plantas do gênero Derris), originários da Amazônia Brasileira, tem demonstrado importância crescente por produzirem uma classe de compostos flavonoídicos relacionados à rotenona, que possuem atividade tóxica para peixes e mamíferos. Neste estudo foi determinado a dose letal 50% (DL50) do extrato alcoólico do pó de Derris spp para três espécies de peixes filogeneticamente diferentes e um mamífero roedor (rato). As DL50 de 2,6 microgramas/ml para Collosoma macropomum (tambaqui), 4,8 microgramas/ml para Oreochromis niloticus (tilápia), 14,2 microgramas/ml para Plecostomus sp (cascudo) e DL50 de 100,0 mg/kg para Rattus norvegicus (rato) denotam acentuadas diferenças entre os valores de DL50, principalmente entre os peixes e o rato. Isto possivelmente é devido a fatores farmaco-cinéticos que se relacionam com as diferentes barreiras teciduais encontradas pelos rotenóides quando administrados pela via oral em mamíferos

In vitro propagation of Podophyllum peltatum.

The lignan podophyllotoxin, occurring in Podophyllum emodi Wall, ex Royale and Podophyllum peltatum. L., is the starting compound for the semi-synthesis of the anticancer drugs etoposide and teniposide. In this study, we evaluate development of an in vitro propagation protocol to rapidly produce high yielding Podophyllum peltatum plants. Rhizome tips were inoculated on MS medium supplied with 4.4 microM N(6)-benzyladenine and 0.025% (w/v) activated charcoal. These explants formed terminal buds, similar to the ones found in nature. These buds were sources of in vitro bud cultures. These bud cultures were classified as: apical, axillary, and adventitious and the effects of various N(6)-benzyladenine concentrations on the three types of bud cultures were evaluated through bud, leaf, and root inductions. Cultures of axillary and adventitious buds were more proliferous for bud induction. Podophyllotoxin contents of in vitro rooted bud and plantlet cultures were similar to the content found in the wild. Plantlets and buds were acclimatized under controlled environment conditions.

Investigation of anti-inflammatory and antinociceptive activities of trans-dehydrocrotonin, a 19-nor-clerodane diterpene from Croton cajucara. Part 1.

The anti-inflammatory and antinociceptive effects of trans-dehydrocrotonin, isolated from the bark of Croton cajucara (Euphorbiaceae), were investigated using several animal models. The trans-dehydrocrotonin produced a significant inhibition of carrageenin-induced paw edema and cotton pellet granuloma in rats. It also inhibited the writhings in mice induced by acetic acid, but did not show a significant effect in the hot-plate test in mice. The LD50 of t-DCTN was 555.0 mg/kg (p.o.) for mice.