Control of the growth of Alicyclobacillus acidoterrestris in industrialized orange juice using rosemary essential oil and nisin.

The use of rosemary essential oil (RO) and its combination with nisin (RO+N) in preventing the multiplication of Alicyclobacillus acidoterrestris in orange juice was evaluated. The minimum inhibitory and bactericidal concentrations (MIC and MBC) for RO were both 125 µg ml-1 while RO+N displayed a synergistic effect. The use of RO and RO+N at concentrations of 1, 4 and 8× MIC in orange juice for 96 h was evaluated in terms of their sporicidal effectiveness. With regard to the action against A. acidoterrestris spores, RO at 8× MIC was sporostatic, whereas RO+N at 1× MIC was sporicidal. Morphological changes in the structure of the micro-organism after treatment were also observed by microscopy. Furthermore, flow cytometric analysis showed that most cells were damaged or killed after treatment. In general, the antioxidant activity after addition of RO+N decreased with time. The results demonstrate that using the combination of RO and nisin can prevent the A. acidoterrestris growth in orange juice.

Ketoconazole-loaded poly-(lactic acid) nanoparticles: Characterization and improvement of antifungal efficacy in vitro against Candida and dermatophytes.

OBJECTIVE: In order to improve the effect of ketoconazole, poly-lactic acid (PLA) nanoparticles containing ketoconazole were prepared, characterized and tested against dermatophytes and Candida spp planktonic and biofilm cells. METHODS: The ketoconazole-PLA nanoparticles obtained by nanoprecipitation were characterized using dynamic light scattering, scanning electron microscopy, transmission electron microscopy, and differential scanning calorimetry. In addition, quantification of encapsulated ketoconazole and the in vitro release profile were determined. Antifungal susceptibility tests against dermatophytes Trichophyton rubrum, Trichophyton mentagrophytes, and Microsporum gypseum and yeasts Candida albicans, C. dubliniensis, C. krusei, C. parapsilosis, and C. tropicalis were performed. RESULTS: Spherical nanoparticles, with a mean diameter of 188.5nm and an encapsulation efficiency of 45% ketoconazole, were obtained. The nanoparticles containing ketoconazole had superior antifungal activity against all tested fungi strains than free ketoconazole. Inhibition of yeast biofilm formation was also achieved. CONCLUSION: Ketoconazole-PLA nanoparticles resulted in better antifungal activity of ketoconazole nanoparticles than free drug against dermatophytes and Candida species, indicating a promising tool for the development of therapeutic strategies.

Preparation, characterization and antidermatophytic activity of free- and microencapsulated cinnamon essential oil.

Essential oils (EO) are effective natural antimicrobials but are susceptible to oxidation. Microencapsulation improves EO stability, reduces toxicity, and controls release. The aim of this study was preparation, characterization and antidermatophytic activity of free and microencapsulated cinnamon essential oil (MP). MP were prepared by the spray drying method and the success of MP encapsulation was confirmed by UV-vis spectroscopy, dynamic light scattering (DLS), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infrared (FT-IR) spectroscopy. The antifungal effect of EO and MP was evaluated by the broth microdilution method against Microsporum gypseum and Trichophyton mentagrophytes. The checkerboard method was used to assess synergistic interactions. Fluorescence microscopy and scanning electron microscopy were used to investigate the inhibition of hyphal growth by EO and MP. A cytotoxic assay was performed using the VERO cell line. Microencapsulated cinnamon essential oil was found to be micrometric, with a round, regular structure. The minimum inhibitory concentration of EO was found to be between 125-250µg/mL, while that of MP was 220.5-440.5µg/mL. EO was synergistic with fluconazole while microencapsulated oil was less cytotoxic than EO.

Piper regnellii extract biopolymer-based microparticles: production, characterization and antifungal activity.

AIMS: This study aims to improve characteristics of Piper regnellii extract to make it applicable in formulations to treat dermatophytosis, also known as ringworm. METHODS AND RESULTS: Microparticles (MPs) were produced by spray drying with gelatin, alginate and chitosan as encapsulating agents; characterized by scanning electron microscopy, encapsulation efficiency, thermal analyses and X-ray diffraction; and tested against Trichophyton rubrum by broth microdilution. Produced MPs had a mean diameter less than 2 µm, an increase in stability and release of the extract and good results for encapsulation efficiency, being 85·6% to gelatin MP, 71·3% to chitosan MP and 60·6% to alginate. MPs preserved the antifungal activity of P. regnellii extract T. rubrum. CONCLUSION: Microencapsulation provided a significant improvement in the stability of the P. regnellii extract and better solubilization of chemical compounds, maintaining the antifungal effect against T. rubrum. SIGNIFICANCE AND IMPACT OF THE STUDY: These results are useful for developing a formulation to treat fungal infections caused by dermatophyte species.

Antimicrobial effects of Piper hispidum extract, fractions and chalcones against Candida albicans and Staphylococcus aureus.

Three chalcones, 2'-hydroxy-4,4',6'-trimethoxychalcone, 2'-hydroxy-4,4',6'-tetramethoxychalcone, and 3,2'-dihydroxy-4,4',6'-trimethoxychalcone, were isolated from the leaves of Piper hispidum in a bioguided fractionation of crude extract. The antimicrobial activity of crude extract of P. hispidum leaves was determined against bacteria Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus and yeasts Candida albicans, C. parapsilosis and C. tropicalis. Fractions and chalcones were tested against C. albicans and S. aureus. The checkerboard assay was performed to assess synergic interactions between extract and antifungal drugs, and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) reduction assay was used to evaluate anti-biofilm effects of extract. The extract was active against yeasts, S. aureus and B. subtilis with MIC values between 15.6 and 62.5µg/mL. Synergistic effects of extract associated with fluconazole and nystatin were observed against C. albicans, with fractional inhibitory concentration indices of 0.37 and 0.24, respectively. The extract was also effective against C. albicans and S. aureus biofilm cells at concentrations of 62.5 and 200µg/mL, respectively. Thus, P. hispidum may be a possible source of bioactive substances with antimicrobial properties.

Antidermatophytic activity of hydroalcoholic extracts from Rosmarinus officinalis and Tetradenia riparia.

Rosmarinus officinalis and Tetradenia riparia are used in folk medicine for the treatment of disease, including infectious diseases and skin disorders. The purpose of this study was to investigate the antifungal activity of hydroalcoholic extracts from R. officinalis and T. riparia against strains of Trichophyton rubrum, T. mentagrophytes and Microsporum gypseum. Hydroalcoholic extracts prepared with dried leaves from R. officinalis, Psidium guajava and T. riparia were assayed against dermatophyte species by the microdilution technique and by microscopy. R. officinalis and T. riparia were the most active against dermatophytes, as determined from the minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC), and were investigated further. Fluorescence microscopy and scanning electron microscopy were used to investigate inhibition of hyphal growth by the two extracts, and showed a strong inhibition and an irregular growth pattern. Both extracts showed good action against dermatophytes, inhibiting fungal growth and causing alterations in their hyphae. Therefore, R. officinalis and T. riparia are potential sources of new compounds for the development of antifungal drugs.

Effects of fluconazole treatment of mice infected with fluconazole-susceptible and -resistant Candida tropicalis on fungal cell surface hydrophobicity, adhesion and biofilm formation.

BACKGROUND: The incidence of Candida tropicalis less susceptible to fluconazole (FLC) has been reported in many parts of the world. OBJECTIVES: The aim of this study was to examine the changes of putative virulence attributes of Candida tropicalis accompanying the development of resistance to FLC in vitro and in vivo. MATERIALS AND METHODS: A FLC-resistant strain (FLC-R) was obtained after sequential exposure of a clinical isolate FLC-sensitive (FLC-S) to increasing concentrations of the antifungal. The course of infection by both strains was analyzed in BALB/c mice. Analyses of gene expression were performed by real-time polymerase chain reaction PCR. The cell surface hydrophobicity, adhesion and biofilm formation were also determined. RESULTS: Development of resistance to FLC could be observed after 15 days of subculture in azole-containing medium. Overexpression of MDR1 and ERG11 genes were observed in FLC-R, and this strain exhibited enhanced virulence in mice, as assessed by the mortality rate. All mice challenged with the FLC-R died and FLC-treatment caused earlier death in mice infected with this strain. All animals challenged with FLC-S survived the experiment, regardless of FLC-treatment. Overall, FLC-R derivatives strains were significantly more hydrophobic than FLC-S strains and showed greater adherence and higher capacity to form biofilm on polystyrene surface. CONCLUSIONS: The expression of virulence factors was higher in FLC-R-C. tropicalis and it was enhanced after FLC-exposure. These data alert us to the importance of identifying microorganisms that show resistance to the antifungals to establish an appropriate management of candidiasis therapy.

Further evidence of the trypanocidal action of eupomatenoid-5: confirmation of involvement of reactive oxygen species and mitochondria owing to a reduction in trypanothione reductase activity.

Our group assays natural products that are less toxic and more effective than available nitroheterocycles as promising therapeutic options for patients with Chagas disease. Our previous study reported the trypanocidal activity of eupomatenoid-5, a neolignan isolated from the leaves of Piper regnellii var. pallescens, against the three main parasitic forms of Trypanosoma cruzi. The present study further characterizes the biochemical and morphological alterations induced by this compound to elucidate the mechanisms of action involved in the cell death of T. cruzi. We show that eupomatenoid-5 induced oxidative imbalance in the three parasitic forms, especially trypomastigotes, reflected by a decrease in the activity of trypanothione reductase and increase in the formation of reactive oxygen species (ROS). A reduction of mitochondrial membrane potential was then triggered, further impairing the cell redox system through the production of more ROS and reactive nitrogen species. Altogether, these effects led to oxidative stress, reflected by lipid peroxidation and DNA fragmentation. These alterations are key events in the induction of parasite death through various pathways, including apoptosis, necrosis, and autophagy.

Effects of (-) mammea A/BB isolated from Calophyllum brasiliense leaves and derivatives on mitochondrial membrane of Leishmania amazonensis.

We have previously demonstrated antileishmanial activity on Leishmania amazonensis of the natural (1-2), synthetic (7) and derivatives of coumarin (-) mammea A/BB (3-6) isolated from the dichloromethane extract of Calophyllum brasiliense leaves. The aim of the present study was to evaluate morphological and ultrastructural alterations in Leishmania amazonensis induced by these compounds. In promastigote forms, all seven compounds produced significant morphological and ultrastructural alterations, as revealed by scanning and transmission electron microscopy. The compound 5,7-dihydroxy-8-(2-methylbutanoyl)-6-(3-methylbutyl)-4-phenyl-chroman-2-one (3), the most active antileishmanial with LD50 of 0.9 µM), induced cell shrinkage and a rounded appearance of the cells. Parasites incubated in the presence of compound (3) showed ultrastructural changes, such as the appearance of mitochondrial swelling with a reduction in the density of the mitochondrial matrix and the presence of vesicles inside the mitochondrion, indicating damage and significant change in this organelle; abnormal chromatin condensation, alterations in the nuclear envelope, intense atypical cytoplasmic vacuolization, and the appearance of autophagic vacuoles were also observed. In addition, the compound (3) may be acting to depolarize the mitochondrial membrane potential of the cells, leading to death of the parasite.

Beta-carboline-3-carboxamide derivatives as promising antileishmanial agents.

Leishmaniasis has an overwhelming impact on global public health especially in tropical and subtropical countries and the currently available antileishmanial drugs have serious side effects and low efficacy. Natural and synthetic compounds have been tested in the past few years against Leishmania and the beta-carboline class of compounds have shown great results in antiparasitic chemotherapy. In the present study, three 1-substituted beta-carboline-3-carboxamides (3-5) and 1-substituted beta-carboline-3-carboxylic acid (2) were synthesized and screened for in vitro activity against L. amazonensis. Compound 5 (N-benzyl 1-(4-methoxy)phenyl-9H-beta-carboline-3-carboxamide) had the best activity against promastigote and axenic amastigote forms with IC(50) of 2·6 and 1·0 µM, respectively. Its CC(50) on macrophages cell line was higher than 2457·0 µM with an SI ratio of 930·2. Against intracellular amastigote forms, it had a dose-dependent relationship with a 50% growth inhibitory concentration of 1·0 µM. Through morphological and ultrastructure analysis of promastigote forms treated with compound 5, alterations on cell shape and number of flagella and nuclear membrane damage were observed. For this, compound 5 supports the idea for more in vitro and in vivo studies.

Antileishmanial activity of an essential oil from the leaves and flowers of Achillea millefolium.

An essential oil was recently extracted from the leaves and flowers of yarrow (Achillea millefolium) and tested for in-vitro activity against Leishmania amazonensis and murine macrophages (i.e. the J774G8 cell line). The median inhibitory concentration (IC(50)) against L. amazonensis promastigotes was 7.8 µg/ml whereas the survival of amastigotes of this pathogen, within peritoneal murine macrophages, was halved by treatment with the oil at 6.5 µg/ml. The mean value for the median cytotoxic concentration of the oil, measured against adherent (uninfected) J774G8 macrophages, was 72.0 µg/ml (i.e. 9.2 and 11.0 times higher, respectively, than the IC(50) against the promastigotes and intracellular amastigotes). Scanning electron microscopy revealed that the oil caused morphological changes in the treated parasites, including alterations in their shape and size. In transmission electron microscopy, promastigotes treated with the oil (at the IC(50) of 7.8 µg/ml) showed various ultrastructural alterations, including changes in the flagellar membrane, abnormal membrane structures, rupture of the plasma membrane, atypical vacuoles, myelin-like figures, and vesicles that resembled autophagic vacuoles.

In vitro anti-trypanosomal activity of elatol isolated from red seaweed Laurencia dendroidea.

SUMMARY: Chagas' disease is a debilitating but comparatively neglected illness that affects about 15 million people. There is an urgent need to develop new, more effective, and less-toxic compounds. In this study, we assessed the in vitro anti-trypanosomal activity of the sesquiterpene elatol from the Brazilian red seaweed Laurencia dendroidea. We used electron microscopy to evaluate the effect of elatol on the morphology and ultrastructure of the parasite. Elatol showed a dose-dependent effect against the epimastigote, trypomastigote, and amastigote forms, with IC50 values of 45.4, 1.38, and 1.01 microm, respectively. Observation of treated intracellular amastigotes by light microscopy demonstrated a total elimination of the infection at a dose of 3.0 microm. In addition, the compound did not affect the red blood cells, and the CC50 value for LLCMK2 cells was 27.0 microm. Transmission and scanning electron micrographs showed aberrant-shaped cells and breaks in the plasma membrane, prominent swollen mitochondria, and extensive formation of cytoplasmic vacuoles in all the forms. This is the first report of the anti-trypanosomal effect of the sesquiterpene elatol.

Effects of a methanolic fraction of soybean seeds on the transcriptional activity of peroxisome proliferator-activated receptors (PPAR)

Since the anti-inflammatory, antidiabetic and hypolipidemic effects of soy isoflavones may be mediated by activation of peroxisome proliferator-activated receptors (PPAR), the present study investigated whether the methanolic fractions obtained from soybean seeds (E1) and soybean seed coats with hypocotyls (E2) could influence PPARα, PPARγ and PPARβ/δ transcriptional activity. The isoflavones from E1 and E2 were quantified by HPLC analysis. E1 and E2 were rich in isoflavones (daidzin, glycitin, genistin, malonyldaidzin, malonylglycitin, malonylgenistin, daidzein, glycitein, and genistein). Moreover, E1 and E2 showed no evidence of genetically modified material containing the gene CP4 EPSPS. To investigate PPAR transcriptional activity, human promonocytic U-937 cells were treated with E1 and E2 (200, 400, 800, and 1600 µg/mL), positive controls or vehicle. Data are reported as fold-activation of the luciferase reporter driven by the PPAR-responsive element. Dose-response analysis revealed that E1 and E2 induced the transcriptional activity of PPARα (P < 0.001), with activation comparable to that obtained with 0.1 mM bezafibrate (positive control) at 1600 µg/mL (4-fold) and 800 µg/mL (9-fold), respectively. In addition, dose-response analysis revealed that E1 and E2 activated PPARβ/δ (P < 0.05), and the activation at 800 µg/mL (4- and 9-fold, respectively) was comparable to that of 0.1 mM bezafibrate (positive control). However, no effect on PPARγ was observed. Activation of PPARα is consistent with the lipid-lowering activity of soy isoflavones in vivo, but further studies are needed to determine the physiological significance of PPARβ/δ activation.

Effects of a methanolic fraction of soybean seeds on the transcriptional activity of peroxisome proliferator-activated receptors (PPAR).

Since the anti-inflammatory, antidiabetic and hypolipidemic effects of soy isoflavones may be mediated by activation of peroxisome proliferator-activated receptors (PPAR), the present study investigated whether the methanolic fractions obtained from soybean seeds (E1) and soybean seed coats with hypocotyls (E2) could influence PPARalpha, PPARgamma and PPARbeta/delta transcriptional activity. The isoflavones from E1 and E2 were quantified by HPLC analysis. E1 and E2 were rich in isoflavones (daidzin, glycitin, genistin, malonyldaidzin, malonylglycitin, malonylgenistin, daidzein, glycitein, and genistein). Moreover, E1 and E2 showed no evidence of genetically modified material containing the gene CP4 EPSPS. To investigate PPAR transcriptional activity, human promonocytic U-937 cells were treated with E1 and E2 (200, 400, 800, and 1600 microg/mL), positive controls or vehicle. Data are reported as fold-activation of the luciferase reporter driven by the PPAR-responsive element. Dose-response analysis revealed that E1 and E2 induced the transcriptional activity of PPARalpha (P < 0.001), with activation comparable to that obtained with 0.1 mM bezafibrate (positive control) at 1600 microg/mL (4-fold) and 800 microg/mL (9-fold), respectively. In addition, dose-response analysis revealed that E1 and E2 activated PPARbeta/delta (P < 0.05), and the activation at 800 microg/mL (4- and 9-fold, respectively) was comparable to that of 0.1 mM bezafibrate (positive control). However, no effect on PPARgamma was observed. Activation of PPARalpha is consistent with the lipid-lowering activity of soy isoflavones in vivo, but further studies are needed to determine the physiological significance of PPARbeta/delta activation.

Antiviral activity and mode of action of a peptide isolated from Sorghum bicolor.

In this paper, we describe the purification of an antiviral peptide from seeds of Sorghum bicolor L. by a procedure that included gel filtration, ion exchange, and high-performance liquid chromatography (HPLC) in a reversed-phase column. Its molecular weight, determined by chromatographic mobility on the Shim-pack DIOL-150 gel permeation column in HPLC, was found to be 2000Da. The peptide designated 2kD peptide strongly inhibited the replication of herpes simplex virus type 1 (HSV-1), dose-dependently, at 40-90% of the control level, after incubation with 10-50 microM of the peptide, with EC(50) and EC(90) values of 6.25 and 15.25 microM, respectively. The IC(50) value of the 2kD peptide against Vero cells was 250 microM. Pre-incubation of HSV-1 with various concentrations of the 2kD peptide showed dose-dependent cytopathic effects (CPE) reduction patterns at concentrations from 6.25 to 50 microM. The presence of the 2kD peptide before HSV-1 infections showed moderate inhibition of virus-induced CPE as compared to during or after infections, with EC(50) values of 12.5, 6.25, and 6.25 microM, respectively. Similar results were observed when the 2kD peptide was assayed against bovine herpes virus (BHV), an enveloped virus like HSV-1. On the other hand, the 2kD peptide showed weak activity against poliovirus type 1, a non-enveloped virus. Taken together, these results indicate that the 2kD peptide was able not only to inhibit the initiation and the spread of infection, but also had an in vitro prophylactic effect against HSV-1 infection.

Antibacterial activity of indole alkaloids from Aspidosperma ramiflorum

We evaluated the antibacterial activities of the crude methanol extract, fractions (I-V) obtained after acid-base extraction and pure compounds from the stem bark of Aspidosperma ramiflorum. The minimum inhibitory concentration (MIC) was determined by the microdilution technique in Mueller-Hinton broth. Inoculates were prepared in this medium from 24-h broth cultures of bacteria (10(7) CFU/mL). Microtiter plates were incubated at 37°C and the MICs were recorded after 24 h of incubation. Two susceptibility endpoints were recorded for each isolate. The crude methanol extract presented moderate activity against the Gram-positive bacteria B. subtilis (MIC = 250 µg/mL) and S. aureus (MIC = 500 µg/mL), and was inactive against the Gram-negative bacteria E. coli and P. aeruginosa (MIC > 1000 µg/mL). Fractions I and II were inactive against standard strains at concentrations of <=1000 µg/mL and fraction III displayed moderate antibacterial activity against B. subtilis (MIC = 500 µg/mL) and S. aureus (MIC = 250 µg/mL). Fraction IV showed high activity against B. subtilis and S. aureus (MIC = 15.6 µg/mL) and moderate activity against E. coli and P. aeruginosa (MIC = 250 µg/mL). Fraction V presented high activity against B. subtilis (MIC = 15.6 µg/mL) and S. aureus (MIC = 31.3 µg/mL) and was inactive against Gram-negative bacteria (MIC > 1000 µg/mL). Fractions III, IV and V were then submitted to bioassay-guided fractionation by silica gel column chromatography, yielding individual purified ramiflorines A and B. Both ramiflorines showed significant activity against S. aureus (MIC = 25 µg/mL) and E. faecalis (MIC = 50 µg/mL), with EC50 of 8 and 2.5 µg/mL for ramiflorines A and B, respectively, against S. aureus. These results are promising, showing that these compounds are biologically active against Gram-positive bacteria.

Antibacterial activity of indole alkaloids from Aspidosperma ramiflorum.

We evaluated the antibacterial activities of the crude methanol extract, fractions (I-V) obtained after acid-base extraction and pure compounds from the stem bark of Aspidosperma ramiflorum. The minimum inhibitory concentration (MIC) was determined by the microdilution technique in Mueller-Hinton broth. Inoculates were prepared in this medium from 24-h broth cultures of bacteria (10(7) CFU/mL). Microtiter plates were incubated at 37 masculineC and the MICs were recorded after 24 h of incubation. Two susceptibility endpoints were recorded for each isolate. The crude methanol extract presented moderate activity against the Gram-positive bacteria B. subtilis (MIC = 250 microg/mL) and S. aureus (MIC = 500 microg/mL), and was inactive against the Gram-negative bacteria E. coli and P. aeruginosa (MIC > 1000 microg/mL). Fractions I and II were inactive against standard strains at concentrations of < or =1000 microg/mL and fraction III displayed moderate antibacterial activity against B. subtilis (MIC = 500 microg/mL) and S. aureus (MIC = 250 microg/mL). Fraction IV showed high activity against B. subtilis and S. aureus (MIC = 15.6 microg/mL) and moderate activity against E. coli and P. aeruginosa (MIC = 250 microg/mL). Fraction V presented high activity against B. subtilis (MIC = 15.6 microg/mL) and S. aureus (MIC = 31.3 microg/mL) and was inactive against Gram-negative bacteria (MIC > 1000 microg/mL). Fractions III, IV and V were then submitted to bioassay-guided fractionation by silica gel column chromatography, yielding individual purified ramiflorines A and B. Both ramiflorines showed significant activity against S. aureus (MIC = 25 microg/mL) and E. faecalis (MIC = 50 microg/mL), with EC50 of 8 and 2.5 microg/mL for ramiflorines A and B, respectively, against S. aureus. These results are promising, showing that these compounds are biologically active against Gram-positive bacteria.

Neolignanas e análise do óleo essencial das folhas de Piper regnellii (Miq.) C. DC. var. pallescens (C. DC.) Yunck / Neolignans and the analysis of the essential oil of Piper regnellii (Miq.) C. DC. var. pallescens (C. DC.) Yunck leaves

O óleo essencial das folhas de Piper regnellii (Miq.) C. DC. var. pallescens (C. DC.) Yunck Piparaceae, coletadas no Horto de Plantas Medicinais da Universidade Estadual de Maringá, foi obtido por hidrodestilação. Uma análise preliminar por CG/EM e RMN 13C foi realizada. O b-mirceno (70 por cento) foi identificado como componente majoritário através da comparação dos espectros de massa e RMN 13C com dados da literatura. Quatro neolignanas foram isoladas do extrato hidroetanólico das folhas e identificadas: eupomatenóide-6, eupomatenóide-5, eupomatenóide-3 e conocarpano. As estruturas dessas substâncias foram estabelecidas por meio de estudos de RMN ¹H e 13C, ¹H x ¹H - COSY, HETCOR, HMBC, gNOE e EM.

The essential oil of Piper regnellii (Miq.) C. DC. var. pallescens (C. DC.) Yunck Piparaceae leaves, which were collected at a tree farm named Horto de Plantas Medicinais of the Universidade Estadual de Maringá, was obtained by hydrodistillation. A preliminary analysis by GC/MS was carried out. b-mirceno (70 percent) was identified as the main constituent by comparing MS and 13C NMR with the literature data. Four neolignans were isolated from the leaves and identified: eupomatenoid-6, eupomatenoid-5, eupomatenoid-3 and conocarpan. Their structures were established by extensive ¹H and 13C NMR, ¹H x ¹H - COSY, HETCOR, HMBC, gNOE and MS spectral studies.

Evaluation of the antioedematogenic, free radical scavenging and antimicrobial activities of aerial parts of Tillandsiastreptocarpa Baker-Bromeliaceae.

The crude methanolic extract of the aerial parts of Tillandsiastreptocarpa was investigated for their acute toxicity and antioedematogenic, antioxidant and antimicrobial activities. Also, the antioedematogenic activity of the hexane fraction resulting from the partition of the crude methanolic extract was evaluated. The methanolic extract and the hexane fraction showed significant (P < 0.05) inhibition of ear oedema, observed at 2 mg/ear in the croton oil-induced mice ear oedema test. In the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging test, a high reactivity and potent antioxidant effect (IC(50) = 0.0056%, w/v) were observed for the methanolic extract. The antimicrobial activity assay showed that the crude methanolic extract was inactive toward Escherichiacoli, Staphylococcusaureus, Pseudomonasaeruginosa, Bacillussubtilis, Candidaalbicans, C. parapsilosis, C. krusei and C. tropicalis (MIC > 500 microg/ml). The methanolic extract showed no toxic effect on mice at a single dose of 2000 mg/kg (p.o). Common side effects including mild diarrhoea, loss of weight and depression were not recorded. The compounds cycloartenol, 4',5-dihydroxy-3',7-dimethoxyflavanone and a mixture of the steroids stigmasterol, beta-sitosterol and campesterol, were isolated from the hexane fraction and identified by spectroscopic methods.

Avaliação da atividade antibacteriana e antifúngica de extratos de plantas utilizados na medicina popular

Foram selecionados extratos de 13 plantas utilizadas na medicina popular brasileira para avaliar a atividade antimicrobiana. Destes, 10 extratos apresentaram níveis variados de atividade antibacteriana. Cinco dos extratos testados, apresentaram compostos com valores de Rf similares a de compostos antibacterianos visíveis na bioautografia. Três destas plantas pertencem à família Compositae indicando que o mesmo composto pode ser responsável pela atividade antibacteriana destas plantas. Atividade anticandida foi observada em 9 extratos de plantas. Os resultados podem explicar o uso etnobotânico das espécies estudadas para o tratamento de várias doenças infecciosas.

Extracts of 13 Brazilian medicinal plants were screened for their antimicrobial activity against bacteria and yeast. Of these, 10 plant extracts showed varied levels of antibacterial activity. Five of the plant extracts presented compounds with Rf values similar to the antibacterial compounds visible on bioautogram. Of these, three plants belong to the Compositae family. This may mean that the same compounds are responsible for the antibacterial activity in these plants. Anticandidal activity was detected in 9 plant extracts. The results might explain the ethnobotanical use of the studied species for the treatment of various infectious diseases.