Chemical composition, antifungal, and anti-virulence action of the stem bark of Hancornia speciosa Gomes (Apocynaceae) against Candida spp.

ETHNOPHARMACOLOGICAL RELEVANCE: Hancornia speciosa Gomes is a fruit and medicinal species used for treating infectious diseases of the genitourinary system. However, its mechanism of action against microbes is still not fully understood. Infections in the genitourinary system caused by Candida spp. are associated with its fungal resistance and pathogenicity. New plant-derived compounds are an alternative to fight these Candida infections. AIM OF THE STUDY: The objective of this study was to evaluate the anti-Candida effects of extracts of the stem bark of H. speciosa. This research investigated the chemical composition of sulfuric ether (EEHS) and methanolic (MEHS) extracts, their drug-modifying action on fluconazole, and their anti-virulence action on the morphological transition of Candida species. MATERIALS AND METHODS: The extracts (EEHS and MEHS) of the stem bark of H. speciosa were chemically characterized via qualitative phytochemical screening and by liquid chromatography coupled with mass spectrometry (UPLC-MS-ESI-QTOF). The extracts were evaluated regarding their antifungal effects and fluconazole-modifying activity against Candida albicans, Candida krusei, and Candida tropicalis using the broth microdilution method. Additionally, the study evaluated the inhibition of fungal virulence in Candida species through morphological transition assays. RESULTS: The phytochemical screening revealed the presence of anthocyanidins, anthocyanins, aurones, catechins, chalcones, flavones, flavonols, flavanones, leucoanthocyanidins, tannins (condensed and pyrogallic), and xanthones in both extracts of the stem bark of H. speciosa. The UPLC-MS-ESI-QTOF analysis identified the same compounds in both extracts, predominating phenolic compounds. Some compounds were first time recorded in this species: gluconic acid, cinchonain IIb, cinchonain Ib isomer, and lariciresinol hexoside isomers. Most of the intrinsic antifungal activity was observed for the MEHS against C. krusei (IC50: 58.41 µg/mL). At subinhibitory concentrations (MC/8), the EEHS enhanced the action of fluconazole against all Candida strains. The MEHS exhibited greater efficacy than fluconazole inhibiting C. krusei growth. The EEHS completely inhibited hyphae appearance and reduced pseudohyphae formation in C. albicans. CONCLUSION: The stem bark of H. speciosa is a rich source of bioactive compounds, especially phenolic. Phenolic compounds can have important roles in fighting infectious diseases of the genitourinary system, such as candidiasis. The extracts of H. speciosa improved the action of the drug fluconazole against Candida species, inhibited hyphae appearance, and reduced pseudohyphae formation. The results of this study can support the development of new therapeutics against resistant strains of Candida.

UPLC-QTOF-MS/MS-based metabolomic approach and gastroprotective effect of two chemotypes of Egletes viscosa (L.) less. against ethanol-induced gastric ulcer in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Egletes viscosa (L.) (macela) is a native wild herb that can be found in different states of northeastern Brazil. The infusions of its flower buds are traditionally used for the treatment of gastrointestinal disorders. E. viscosa possesses two chemotypes (named A and B), distinguishable by the composition of the essential oil from the flower buds. Although there are previous studies of the gastroprotective effect of the isolated constituents of E. viscosa, its infusions have not been investigated yet. AIM OF THE STUDY: The present study aimed to evaluate and compare the chemical composition and the gastroprotective effect of flower bud infusions of E. viscosa from chemotype A (EVCA) and chemotype B (EVCB). MATERIALS AND METHODS: Sixteen infusions were brewed with flower buds according to the traditional preparation mode and were analyzed through a UPLC-QTOF-MS/MS based metabolomic approach for determination of their metabolic fingerprints and quantification of bioactive compounds. Afterward, these data were analyzed by chemometric methods (OPLS-DA) for discrimination of the two chemotypes. Additionally, infusions of EVCA and EVCB (50, 100 and 200 mg/kg, p.o.) were evaluated on gastric ulcers induced by absolute ethanol (96%, 0.2 mL, p.o.) in mice. To elucidate the gastroprotective mechanisms, the effect of EVCA and EVCB on gastric acid secretion and gastric wall mucus was determined and the role of TRPV1 channels, prostaglandins, nitric oxide and KATP channels were assessed. Moreover, the oxidative stress-related parameters and the histological aspects of the stomach tissue were analyzed. RESULTS: The chemotypes can be discriminated from each other using UPLC-QTOF-MS/MS chemical fingerprints. Both chemotypes presented similar chemical compositions, consisting basically of caffeic acid derivatives, flavonoids and diterpenes. The quantification of bioactive compounds demonstrated that chemotype A possesses more ternatin, tanabalin and centipedic than chemotype B. EVCA and EVCB (50, 100 and 200 mg/kg, p.o.) significantly decreased the severity of ethanol-induced gastric lesions, as shown by a reduction in histological alterations and leucocyte infiltration in gastric tissue. The gastroprotective mechanism of both infusions involves an antioxidant effect, maintenance of gastric mucus and reduction gastric secretion. Stimulation of endogenous prostaglandins and nitric oxide release, activation of TRPV1 channels, and KATP channels are also involved in the gastroprotection of the infusions. CONCLUSION: The gastroprotective effect of EVCA and EVCB was equivalent and mediated through antioxidant and antisecretory actions, including the activation of TRPV1 receptors, stimulation of endogenous prostaglandins and nitric oxide, and opening of KATP channels. The presence of caffeic acid derivatives, flavonoids and diterpenes in both infusions is involved in mediating this protective effect. Our findings support the traditional use of infusions of E. viscosa for gastric disorders regardless of the chemotype.

Endophytic Fungus of Achyrocline satureioides: Molecular Identification, Chemical Characterization, and Cytotoxic Evaluation of its Metabolites in Human Melanoma cell line.

Endophytic fungi are important sources of anticancer compounds. An endophytic fungus was isolated from the medicinal plant Achyrocline satureioides, and molecularly identified as Biscogniauxia sp. (family Xylariaceae) based on partial nucleotide sequences of the internal transcribed spacer genomic region (GenBank Accession No. ON257911). The chemical characterization and cytotoxic properties of secondary metabolites produced by Biscogniauxia sp. were evaluated in a human melanoma cell line (A375). The fungus was grown in potato-dextrose liquid medium for 25 days, and the extracted compounds were subjected to solid-phase fractionation to obtain the purified FDCM fraction, for which the metabolites were elucidated via ultra-performance chromatography coupled to a mass spectrometer. In the present study, 17 secondary metabolites of Biscogniauxia sp., including nine polyketide derivatives, five terpenoids, and three isocoumarins, were putatively identified. This is the first study to report of the ability of Biscogniauxia sp. in the production of isocoumarin orthosporin; the terpenoids nigriterpene A and 10-xylariterpenoid; the polyketide derivatives daldinin C, 7'dechloro-5'-hydroxygriseofulvin, daldinone D, Sch-642305, curtachalasin A, cytochalasin E, epoxycytochalasins Z8, Z8 isomer, and Z17. Furthermore, this study has reported the biosynthesis of Sch-642305 by a Xylariaceae fungus for the first time. FDCM significantly reduced the viability and proliferation of human melanoma cells at half-maximal inhibitory concentrations ​​of 10.34 and 6.89 µg/mL, respectively, and induced late apoptosis/necrosis and cell cycle arrest in G2/M phase after 72 h of treatment. Given its ability to produce unique metabolites with promising cytotoxic effects, Biscogniauxia sp. of A. satureioides may be a reservoir of compounds with important therapeutic applications.

Modeling the effect of Croton blanchetianus Baill essential oil on pathogenic and spoilage bacteria.

This study aimed to evaluate and model the antimicrobial action of different concentrations of Croton blanchetianus essential oil (CBEO) on the behavior of six bacterial species in vitro. CBEO extraction was performed by hydrodistillation and characterized by CG-MS. CBEO solutions in culture media were tested at 0.90, 1.80, 2.71, and 4.51 mg of CBEO/mL, against foodborne bacteria: pathogenic bacteria (Staphylococcus aureus, Listeria monocytogenes and Salmonella Enteritidis at 35 °C), a non-pathogenic Escherichia coli (at 35 °C), and spoilage bacteria (Weissella viridescens and Leuconostoc mesenteroides at 30 °C). The CBEO major compounds were eucalyptol, α-pinene, sativene, E-caryophyllene, bicyclogermacrene, and spatulenol. Baranyi and Roberts (growth) and Weibull (inactivation) primary models, along with power and hyperbolic secondary models, were able to describe the data. CBEO inactivated L. monocytogenes, S. aureus, L. mesenteroides and W. viridescens at all applied concentrations. CBEO did not inactivate S. Enteritidis and E. coli, but their growth rates were reduced.

Anti-inflammatory withajardins from the leaves of Athenaea velutina.

Withajardins, uncommon modified withanolide-type steroids, have been isolated exclusively from plants of the Solanaceae family so far. Two undescribed withajardins and the known tuboanosigenin were isolated from the hexane/EtOAc 1:1 extract from Athenaea velutina leaves. Their structures were established by an extensive analysis of 1D and 2D-NMR and HRMS data. The absolute configuration was determined by X-ray diffraction (withajardin L and tuboanosigenin) and circular dichroism (CD) analyses (withajardin M). The anti-inflammatory activity of compounds was evaluated through the inhibition of the lipopolysaccharide (LPS)-induced nitric oxide (NO), TNF-α, and IL-6 release in RAW264.7 cells. The cell viability effects to RAW 264.7 cells showed IC50 values of 74.4-354.4 µM. The compounds attenuated LPS-induced release of NO and decreased pro-inflammatory cytokines TNF-α and IL-6 in RAW264.7 cells.

Anti-Candida Properties of Gossypium hirsutum L.: Enhancement of Fungal Growth, Biofilm Production and Antifungal Resistance.

(1) Background: Candida is a genus of yeasts with notable pathogenicity and significant ability to develop antimicrobial resistance. Gossypium hirsutum L., a medicinal plant that is traditionally used due to its antimicrobial properties, has demonstrated significant antifungal activity. Therefore, this study investigated the chemical composition and anti-Candida effects of aqueous (AELG) and hydroethanolic (HELG) extracts obtained from the leaves of this plant. (2) Methods: The extracts were chemically characterized by UPLC-QTOF-MS/MS, and their anti-Candida activities were investigated by analyzing cell viability, biofilm production, morphological transition, and enhancement of antifungal resistance. (3) Results: The UPLC-QTOF-MS/MS analysis revealed the presence of twenty-one compounds in both AELG and HELG, highlighting the predominance of flavonoids. The combination of the extracts with fluconazole significantly reduced its IC50 values against Candida albicans INCQS 40006, Candida tropicalis INCQS 40042, and C. tropicalis URM 4262 strains, indicating enhanced antifungal activity. About biofilm production, significant inhibition was observed only for the AELG-treated C. tropicalis URM 4262 strain in comparison with the untreated control. Accordingly, this extract showed more significant inhibitory effects on the morphological transition of the INCQS 40006 and URM 4387 strains of C. albicans (4) Conclusions: Gossypium hirsutum L. presents promising antifungal effects, that may be potentially linked to the combined activity of chemical constituents identified in its extracts.

Evidence for antioxidant and anti-inflammatory potential of mango (Mangifera indica L.) in naproxen-induced gastric lesions in rat.

This study investigated the anti-inflammatory and antioxidant effects of hydroalcoholic extracts of mango peel and pulp on oxidative damage in a naproxen-induced gastric injury rat model. The extracts were assessed for antioxidant activity (ABTS and FRAP methods), and the phenolic profile was investigated with UPLC-QToF-MSE . Gastric damage was evaluated in vivo by assessing the membrane lipid peroxidation (malondialdehyde (MDA) content), myeloperoxidase (MPO) enzyme activity, and glutathione (GSH) content. Mango peel and pulp contained high contents of bioactive compounds, particularly phenolics (69.50-5.287.70 mg gallic acid equivalents/100 g), carotenoids (651.30-665.50 µg/100 g), and vitamin C (21.59-108.19 mg/100 g). UPLC-QToF-MSE analysis identified 17 phenol compounds, including gallotannins, glycosylated flavonoids, and xanthone. The hydroalcoholic extracts of mango peel and pulp (LPe and LPu, respectively) significantly reduced the MPO activity and MDA content. In addition to preventing naproxen-induced GSH decline, LPe (30 mg/kg) and LPu (10 mg/kg) restored its content to normal levels. LPe and LPu neutralized the oxidizing agents triggered by naproxen and reduced the severity of gastric lesions owing to their antioxidant properties.

Untargeted GC/MS-based approach for identification of anti-inflammatory alkaloids from Hippeastrum elegans (Amaryllidaceae) using a human neutrophil model.

Hippeastrum elegans is an Amaryllidaceae species producing alkaloids with pharmaceutical potential including lycorine and galanthamine. Herein, we developed a non-targeted metabolomic study associated to chemometrics and biological evaluations to identify the H. elegans constituents that were able to reduce the human neutrophils proinflammatory mechanisms. The alkaloid fractions were extracted from bulbs cultivated for 15 months (m) and harvested in six harvest periods (5, 7, 9, 11, 13, and 15 m). The GC-MS analysis allowed the detection of 41 alkaloids being 31 identified. All alkaloid components varied over the cultivation and most of them were lycorine-type skeletons. Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) distinguished three groups according to the chemical profile (group I: 5, 7, and 9 m; group II: 11 m and group III: 13 and 15 m). Therefore, the biological assays were only performed with one of the representative samples of each group: 7 m, 11 m and 15 m. None of them was toxic to human neutrophils by LDH activity and MTT test. The 7 m and 15 m-alkaloid fractions showed anti-inflammatory effects by reducing human neutrophil degranulation. However, the former one was more effective in inhibiting the cell activation based on the reduction of myeloperoxidase (MPO) release and reactive oxygen species (ROS) production. Afterwards, Partial Least Squares analysis (PLS) indicated lycorine and 11,12-dehydro-2-methoxy-assoanine as the compounds responsible for the anti-inflammatory activity of the bioactive fraction. Thus, the 7 m-alkaloid fraction of H. elegans seems to be a promising anti-inflammatory drug that deserves additional research.

UPLC-HRMS and NMR applied in the evaluation of solid-phase extraction methods as a rational strategy of dereplication of Phyllanthus spp. aiming at the discovery of cytotoxic metabolites.

The classical approach to drug discovery from natural products (NP's) requires strenuous and complex purification steps for the isolation and structural elucidation. Modern strategies as dereplication aim to accelerate the identification of known compounds present in a crude or partially purified extract. In this work, we investigated the influence of the solid-phase extraction (Oasis, Plexa, and Agilent C18 cartridges with and without organic modifiers) chemical profile obtained by UPLC-QTOF-MS and NMR and cytotoxicities of aqueous extracts from Phyllanthus niruri and P. amarus. Our results showed differences between the SPE cartridges and the mass recovered. P. niruri showed higher mass recovery than P. amarus indicating a higher amount of secondary metabolites. The UPLC-QTOF-MS analysis revealed that P. niruri crude extract presents higher contents of phenolic compounds than P. amarus. According to NMR analysis, P. niruri contained more tyrosine, corilagin, and glycosidic residues while P. amarus, presented higher content of ellagic acid. The different stationary phases, as well as mobile phases for exploratory SPE, enabled the exploitation of the different chemical functionalities within the Phyllanthus species. The SPE (MeOH:H2O 70:30 with C18 cartridges) samples showed greater in vitro cytotoxicity than the crude extracts, with IC50 ranging from 8.01 to 94.92 µg mL-1 against the tumor lines tested. The solid phase extraction allowed the concentration of molecules with desirable physicochemical characteristics, which might increase the hit of therapeutically useful substances.

Endophytic Fungus Isolated From Achyrocline satureioides Exhibits Selective Antiglioma Activity-The Role of Sch-642305.

Glioblastoma is the most devastating primary brain tumor. Current treatment is palliative, making necessary the development of new therapeutic strategies to offer alternatives to patients. Therefore, endophytes represent an interesting source of natural metabolites with anticancer potential. These microorganisms reside in tissues of living plants and act to improve their growth. Evidence revealed that several medicinal plants are colonized by endophytic fungi producer of antitumor metabolites. Achyrocline satureioides is a Brazilian medicinal plant characterized by its properties against gastrointestinal disturbances, anticancer and antioxidant effects. However, there are no reports describing the endophytic composition of A. satureioides. The present study proposes the isolation of endophytic fungus from A. satureioides, extract preparation, phytochemical characterization and evaluation of its antiglioma potential. Our data showed that crude extracts of endophyte decreased glioma viability with IC50 values of 1.60-1.63 µg/mL to eDCM (dichloromethane extract) and 37.30-55.12 µg/mL to eEtAc (ethyl acetate extract), respectively. Crude extracts induced cell death by apoptosis with modulation of redox status. In order to bioprospect anticancer metabolites, endophytic fungus extracts were subjected to guided fractionation and purification yielded five fractions of each extract. Six of ten fractions showed selective antiproliferative activity against glioma cells, with IC50 values ranged from 0.95 to 131.3 µg/mL. F3DCM (from eDCM) and F3EtAc (from eEtAc) fractions promoted C6 glioma toxicity with IC50 of 1.0 and 27.05 µg/mL, respectively. F3EtAc fraction induced late apoptosis and arrest in G2/M stage, while F3DCM promoted apoptosis with arrest in Sub-G1 phase. Moreover, F3DCM increased antioxidant defense and decreased ROS production. Additionally, F3DCM showed no cytotoxic activity against astrocytes, revealing selective effect. Based on promising potential of F3DCM, we identified the production of Sch-642305, a lactone, which showed antiproliferative properties with IC50 values of 1.1 and 7.6 µg/mL to C6 and U138MG gliomas, respectively. Sch-642305 promoted arrest on cell cycle in G2/M inducing apoptosis. Furthermore, this lactone decreased glioma cell migration and modulated redox status, increasing superoxide dismutase and catalase activities and enhancing sulfhydryl content, consequently suppressing reactive species of oxygen generation. Taken together, these results indicate that metabolites produced by endophytic fungus isolated from A. satureioides have therapeutic potential as antiglioma agent.

Chemical Composition of Essential Oil of Leaves from Lippia schaueriana Mart. Collected in the Caatinga Area.

Lippia schaueriana Mart. (Verbenaceae) is an endemic species of Caatinga with a restricted distribution to the states of Bahia and Pernambuco, which presents itself as a potential source of raw material for extraction of essential oil and exploitation by the chemical and pharmaceutical industries. Considering that there are no reports in the literature of research carried out with this species, this paper aimed to establish-for the first time-the chemical composition of its essential oil. The essential oil of the dry leaves at room temperature was obtained by hydrodistillation after 3 h of extraction and the phytochemical analyzes were done by gas chromatography coupled to mass spectrometry (GC/MS). The main compounds found in the oil of leaves were piperitone oxide (51.25%), caryophyllene (17.76%), limonene (8.06%), spathulenol (6.63%), and piperitone (2.90%). The piperitone oxide is a compound described in the literature that shows antinociceptive, cardiovascular, analgesic, and relaxing activities, as well as fungicidal and insecticidal effect, which gives it an interesting potential for the alternative control of agricultural pests.

Metabolomic profile of Schinopsis brasiliensis via UPLC-QTOF-MS for identification of biomarkers and evaluation of its cytotoxic potential.

Schinopsis brasiliensis is a plant typically found in the caatinga biome (northeastern Brazil). Its leaves and bark have been used for the treatment of health dysfunctions such as cough, influenza, diarrhea, throat inflammation, and sexual impotence. However, there is a lack of knowledge regarding the chemical composition and pharmacological activities of this plant. High-performance liquid chromatography coupled to high-resolution mass spectrometry (UPLC-QTOF-MSE) allowed the partial identification of 33 compounds, including isomers from leaf, branch, and bark samples, with 16 compounds reported for the first time (corilagin, chlorogenic acid, and quercetin derivatives) in S. brasiliensis. Principal component analysis efficiently distinguished the respective parts of the plant. Orthogonal partial least squares discriminatory analysis, together with the variable importance in projection and S-Plot graphs were used to identify 23 biomarker compounds associated with cytotoxic activity against a colorectal cancer cell line.

Chemical profiling of guarana seeds (Paullinia cupana) from different geographical origins using UPLC-QTOF-MS combined with chemometrics.

Paullinia cupana, commonly known as guarana, is an Amazonian fruit whose seeds are used to produce the powdered guarana, which is rich in caffeine and consumed for its stimulating activity. The metabolic profile of guarana from the two largest producing regions was investigated using UPLC-MS combined with multivariate statistical analysis. The principal component analysis (PCA) showed significant differences between samples produced in the states of Bahia and Amazonas. The metabolites responsible for the differentiation were identified by orthogonal partial least squares discriminant analysis (OPLS-DA). Fourteen phenolic compounds were characterized in guarana powder samples, and catechin, epicatechin, B-type procyanidin dimer, A-type procyanidin trimer and A-type procyanidin dimer were the main compounds responsible for the geographical variation of the samples.

Composição química e eficácia do óleo essencial e do extrato etanólico de Alpinia zerumbet sobre Staphylococcus aureus / Chemical composition and efficacy of essential oil and ethanol extract of Alpinia zerumbet on Staphylococcus aureus

O presente trabalho descreve a atividade antibacteriana do óleo essencial e do extrato etanólico das folhas de Alpinia zerumbet (colônia) sobre cepas de Staphylococcus aureus isoladas de vacas com mastite subclínica e cepas padrão ATCC 29213 e ATCC 25923, por meio do método de difusão em ágar. Foram utilizados 10 tratamentos contendo diferentes concentrações do óleo essencial e do extrato etanólico (100,0; 50,0; 25,0; 12,5 e 6,3 mg.mL-1) e o grupo controle (álcool etílico a 50% e Tween a 1%). Os constituintes majoritários do óleo essencial foram p -cimeno (32,72%), 1,8-cineol (24,05%) e 4-terpineol (20,23%), sendo esses determinados por cromatografia a gás acoplada a espectrometria de massas e cromatografia a gás com detector de ionização de chama (CG-EM/DIC). No extrato etanólico foi detectado o ácido elágico e três flavonoides: rutina, quercetina e campferol, por meio de cromatografia a líquido de alta eficiência acoplada a detector de arranjo de diodo (CLAE-DAD). Todas as cepas apresentaram sensibilidade aos tratamentos com óleo essencial e extrato etanólico. A melhor resposta foi obtida com o óleo essencial de A. zerumbet que, na concentração de 100 mg.mL-1 proporcionou inibição total do crescimento bacteriano. Esses resultados sugerem o potencial antibacteriano do óleo essencial e do extrato etanólico de A. zerumbet no controle da mastite bovina.(AU)

The present work describes the antibacterial activity of the essential oil and the ethanol extract from leaves of Alpinia zerumbet (colônia) on Staphylococcus aureus strains isolated from cows with subclinical mastitis and standard strains ATCC 29213 and ATCC 25923, using the agar diffusion method. Ten treatments containing different concentrations of essential oil and ethanol extract (100.0; 50.0; 25.0; 12.5 and 6.3 mg.mL-1) and the control group (50% ethyl alcohol and 1% Tween solutions) were used for antimicrobial testing. The major constituents of the essential oil were p -cimeno (32.72%), 1.8-cineol (24.05%) and 4-terpineol (20.23%), which were determined by gas chromatographymass spectrometry and gas chromatography - flame ionization detector (CG-MS/FID). Ellagic acid and three flavonoids (rutin, quercetin and campferol) were detected in the ethanol extract by means of high performance liquid chromatography-photodiode array detector (HPLC-PDA). All strains showed sensitivity to the treatments with essential oil and the ethanol extract. The best response was obtained with A. zerumbet essential oil at a 100 mg.mL-1, showing complete inhibition of bacterial growth. These results demonstrate the antibacterial potential of essential oil and ethanol extract of A. zerumbet in the control of bovine mastitis.(AU)

Vasorelaxant and antihypertensive effects of methanolic fraction of the essential oil of Alpinia zerumbet.

Alpinia zerumbet is used in folk medicine in Brazil to treat hypertension. However, several pathways involved in the mechanism of vasorelaxation are still unclear. This study was designed to verify the antihypertensive effect of the methanolic fraction of the essential oil of A. zerumbet (MFEOAz) and to characterize its mechanism of action. The thoracic aortic rings from the Wistar rats were perfused in the organ chambers filled with Kreb's solution, where the tension of each ring was measured. The antihypertensive effect of MFEOAz was assessed in rats submitted to chronic hypertension by inhibition of nitric oxide synthesis by indirect measurement of blood pressure with indirect tail cuff method. MFEOAz relaxed phenylephrine and KCl-induced contraction of either endothelium-intact or endothelium-denuded rat aortic rings in a concentration-dependent manner. Pre-incubation with MFEOAz (100 and 300 µg/mL) in Ca(2+)-free Krebs solution attenuated phenylephrine- or caffeine-induced contraction. Pre-incubation with L-NAME, ODQ, wortmannin, atropine, indomethacin, catalase, SOD, TEA, 4-aminopyridine, glibenclamide, apamin, charybdotoxin, or iberiotoxin did not affect MFEOAz-induced relaxation. The intragastric administration of MFEOAz induced an antihypertensive effect. MFEOAz it seems inhibited the calcium influx via voltage-operated calcium channels and receptor-operated calcium channels, as well as inhibition of calcium mobilization from intracellular stores.

Effects of amburoside A and isokaempferide, polyphenols from Amburana cearensis, on rodent inflammatory processes and myeloperoxidase activity in human neutrophils.

The present study evaluated the anti-inflammatory activity of amburoside A (a phenol glucoside) and isokaempferide (a flavonol) isolated from the trunk bark of Amburana cearensis, a medicinal plant used in northeast Brazil for the treatment of asthma. Animals (male Wistar rats or Swiss mice) pre-treated with amburoside A (25 and 50 mg/kg) or isokaempferide (12.5, 25 and 50 mg/kg), orally or intraperitoneally, showed a significant inhibition of the paw oedema induced by carrageenan (1%), prostaglandin E(2) (30 nmol/paw), histamine (200 microg/paw) or serotonin (200 microg/paw). Histological and morphometric evaluations of the rat paw oedema induced by carrageenan showed that amburoside A and isokaempferide also inhibited the accumulation of inflammatory cells. Amburoside A reduced significantly the paw oedema and the increase in vascular permeability induced by dextran, as related to the control group. Similar results were observed with the isokaempferide pre-treatment. Furthermore, amburoside A or isokaempferide inhibited both leucocyte and neutrophil migrations, in mouse peritoneal cavity, after the carrageenan injection. The polyphenols were not cytotoxic and blocked N-formyl-methyl-leucyl-phenylalanine-induced myeloperoxidase release and activity in human neutrophils. In addition, amburoside A and isokaempferide at 50 and 100 microg/ml concentrations reduced significantly the lipopolysaccharide-mediated increase in tumour necrosis factor-alpha (TNF-alpha) levels. These results provide, for the first time, evidence to support the anti-inflammatory activity of amburoside A and isokaempferide that seems to be related to an inhibition of inflammatory mediators, such as TNF-alpha, as well as histamine, serotonin and prostaglandin E(2), besides leucocyte infiltration in a dose- or concentration-dependent manner. These anti-inflammatory effects can be explained, at least in part, by the ability of these compounds to reduce neutrophil degranulation, myeloperoxidase activity, mediators as well as TNF-alpha secretion.