Berberine-fluconazole microparticle-based combination therapy to treat candidiasis infections.

AIM: This study aims to incorporate alginate microparticles containing berberine and fluconazole into two different types of pharmaceutical formulations, to subsequently evaluate the antifungal activity against Candida albicans. METHODS AND RESULTS: Alginate microparticles containing BBR (berberine) and FLU (fluconazole) were produced by the spray-drying technique, characterized and incorporated in two pharmaceutical formulations, a vaginal cream and artificial saliva. Broth microdilution, checkerboard, time-kill curve, and scanning electron microscopy were carried out to determine the antifungal effects of BBR and FLU against C. albicans. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values of free BBR were 125 µg ml-1. Synergism between BBR and FLU was demonstrated by a fractional inhibitory concentration index (FICI) = 0.0762. The time-kill curve for the combination BBR + FLU showed a more pronounced decrease in fungal growth in comparison to free drugs, and an antibiofilm effect of BBR occurred in the formation and preformed biofilm. CONCLUSION: Alginate microparticles containing BBR and FLU were obtained and incorporated in a vaginal cream and artificial saliva. Both formulations showed good stability, antifungal effects, and organoleptic characteristics, which suggest that BBR-FLU microparticles in formulations have potential as antifungal therapy.

Synthetic dibenzylideneketones as promising anti-herpes simplex virus type 1 agents.

New antiviral agents for the treatment of herpes simplex virus type 1 (HSV-1) infection, which causes a highly prevalent and incurable disease, are needed. Here, we report for the first time the in vitro anti-HSV-1 activity of two dibenzylideneketone compounds: DBK1 and DBK2. DBK1 demonstrated virucidal activity, and high-resolution scanning electron microscopy showed that it caused morphological changes in the HSV-1 envelope. DBK2 was able to reduce HSV-1 plaque size in vitro. The DBKs are promising anti-HSV-1 candidates, as they exhibit low toxicity and exert an antiviral effect by acting at the early stages of HSV-1-host cell interaction.

Chemical composition and insecticidal activity of Garcinia gardneriana (Planchon & Triana) Zappi (Clusiaceae) essential oil / Composición química y actividad insecticida del aceite esencial de Garcinia gardneriana (Planchon & Triana) Zappi (Clusiaceae)

The present study aimed to analyze the chemical composition of the essential oil from Garcinia gardneriana (Planchon & Triana) Zappi leaves and fruits, and to determine its acaricidal activity on Rhipicephalus microplusy larval packet test and larvicidal action on Aedes aegyptiby larval immersion test. The chemical analysis of the essential oil by gas chromatography-mass spectrometry identified sesquiterpene hydrocarbons and oxygenated sesquiterpenes in bacupari leaves and fruits, and α-cedrene, α-chamigrene, α-trans-bergamotene, and ß-curcumene as major compounds. Essential oil from leaves of G. gardneriana presented acaricidal activity on R. microplus (LC50= 4.8 mg/mL; LC99= 10.8 mg/mL) and larvicidal effect on A. aegypti (LC50= 5.4 mg/mL; LC99 = 11.6 mg/mL), where as essential oil from the fruits of G. gardneriana showed LC50= 4.6 mg/mL and LC99= 8.9 mg/mL against R. microplus and LC50= 6.4 mg/mL and LC99= 13.9 mg/mL against A. aegypti. These results thus demonstrate the potential acaricidal and larvicidal activity of essential oil of G. gardneriana, offering new perspectives for the realization of bioassays from this essential oil.

El presente estudio tuvo como objetivo analizar la composición química del aceite esencial de las hojas y frutos de Garcinia gardneriana (Planchon & Triana) Zappi, y determinar su actividad acaricida en Rhipicephalus microplus y larvicida en Aedes aegypti empleando la prueba de inmersión de larvas. El análisis químico del aceite esencial por cromatografía de gases-espectrometría de masas identificó hidrocarburos sesquiterpénicos y sesquiterpenos oxigenados en hojas y frutos de bacupari, y α-cedreno, α-chamigreno, α-trans-bergamoteno y ß-curcumeno como compuestos principales. El aceite esencial obtenido de las hojas de G. gardneriana presentó actividad acaricida en la garrapata del ganado (LC50= 4,8 mg/mL; LC99= 10,8 mg/mL) y actividad larvicida en A. aegypti (LC50= 5,4 mg/mL; LC99= 11,6 mg/mL), así como, el aceite esencial obtenido de los frutos de G. gardneriana mostró LC50= 4,6 mg/mL y LC99= 8,9 mg/mL contra las larvas de garrapatas de ganado y LC50= 6,4 mg/mL y LC99= 13,9 mg/mL en las larvas de A. aegypti. Por lo tanto, estos resultados demuestran la actividad acaricida y larvicida del aceite essencial de G. gardneriana, ofreciendo nuevas perspectivas para la realización de bioensayos a partir de este aceite esencial.

Larvicidal activity of piperovatine and dichloromethane extract from Piper corcovadensis roots against mosquitoes Aedes aegypti L / Actividad larvicida de piperovatina y extracto de diclorometano de las raíces de Piper corcovadensis contra mosquitos vectores del dengue Aedes aegypti L

The research of new substances capable of controlling the Aedes aegypti mosquito is urgent due to the increase in the transmission of the diseases such as dengue, chikungunya and Zika virus by the vector. Thus, the aim of this study was to evaluate the larvicidal activity of crude extract of Piper corcovadensis roots, a native plant from Brazil, and of the isolated compound piperovatine against larvae of A. aegypti by the larval immersion test. The lethal concentration that killed 50% (LC50) and 99% (LC99) of larvae was determined by Probit analysis. The results indicated high larvicidal activity on A. aegypti larvae for crude extract of Piper corcovadensis roots with LC50 of 4.86 µg/mL and LC99 of 15.50 µg/mL and piperovatine with LC50 of 17.78 µg/mL and LC99 of 48.55 µg/mL. This work opens new perspectives to the development of future products with crude extract of Piper corcovadensis roots and piperovatine that can be applied to mosquito control.

La investigación de nuevas sustancias capaces de controlar el mosquito Aedes aegypti es urgente debido al aumento en la transmisión de enfermedades como el dengue, el chikungunya y el virus Zika por el vector. Por lo tanto, el objetivo de este estudio fue evaluar la actividad larvicida del extracto crudo de las raíces de Piper corcovadensis, una planta nativa de Brasil, y del compuesto aislado piperovatine contra larvas de A. aegypti mediante la prueba de inmersión larvaria. La concentración letal que mató al 50% (LC50) y al 99% (LC99) de larvas se determinó mediante análisis Probit. Los resultados indicaron una alta actividad larvicida en larvas de A. aegypti para extracto crudo de las raíces de Piper corcovadensis con LC50 de 4.86 µg/mL y LC99 de 15.50 µg/mL y piperovatine con LC50 de 17.78 µg/mL y LC99 de 48.55 µg/mL. Este trabajo abre nuevas perspectivas para el desarrollo de futuros productos con extracto crudo de las raíces de Piper corcovadensis y piperovatine que pueden aplicarse al control de mosquitos.

Quinoxaline derivatives as potential antitrypanosomal and antileishmanial agents.

Continuous efforts have been made to discover new drugs for the treatment of Chagas' disease, human African trypanosomiasis, and leishmaniasis. We have previously reported the synthesis and antileishmanial and antitrypanosomal (Y strain) properties of 2,3-disubstituted quinoxalines. Considering their promising antiparasitic potential, the present study was conducted to expand our search and take advantage of high-throughput assays to investigate the effects of quinoxaline derivatives against Leishmania donovani, Trypanosoma brucei, and Trypanosoma cruzi (Tulahuen strain). These compounds were active against the kinetoplastid parasites that were evaluated. The 2-chloro-3-methylsulfoxylsulfonyl and 2-chloro-3-methylsulfinyl quinoxalines were the most potent, and some of these derivatives were even more active than the reference drugs. Although the 2,3-diaryl-substituted quinoxalines were not active against all of the parasites, they were active against T. brucei and intracellular amastigotes of T. cruzi, without interfering with mammalian cell viability. These compounds presented encouraging results that will guide our future studies on in vivo bioassays towards the mode of action.

In vitro Cytotoxicity and Anti-herpes Simplex Virus Type 1 Activity of Hydroethanolic Extract, Fractions, and Isolated Compounds from Stem Bark of Schinus terebinthifolius Raddi.

BACKGROUND: Herpes simplex virus type 1 (HSV-1) is associated with orofacial infections and is transmitted by direct contact with infected secretions. Several efforts have been expended in the search for drugs to the treatment for herpes. Schinus terebinthifolius is used in several illnesses and among them, for the topical treatment of skin wounds, especially wounds of mucous membranes, whether infected or not. OBJECTIVE: To evaluate the cytotoxicity and anti-HSV-1 activity of the crude hydroethanolic extract (CHE) from the stem bark of S. terebinthifolius, as well as its fractions and isolated compounds. MATERIALS AND METHODS: The CHE was subjected to bioguided fractionation. The anti-HSV-1 activity and the cytotoxicity of the CHE, its fractions, and isolated compounds were evaluated in vitro by SRB method. A preliminar investigation of the action of CHE in the virus-host interaction was conducted by the same assay. RESULTS: CHE presented flavan-3-ols and showed anti-HSV-1 activity, better than its fractions and isolated compounds. The class of substances found in CHE can bind to proteins to form unstable complexes and enveloped viruses, as HSV-1 may be vulnerable to this action. Our results suggest that the CHE interfered with virion envelope structures, masking viral receptors that are necessary for adsorption or entry into host cells. CONCLUSION: The plant investigated exhibited potential for future development treatment against HSV-1, but further tests are necessary, especially to elucidate the mechanism of action of CHE, as well as preclinical and clinical studies to confirm its safety and efficacy. SUMMARY: Crude hydroethanolic extract (CHE) presents promising activity against herpes simplex virus type 1 (HSV 1), with selectivity index (SI) = 22.50CHE has flavan-3-ols in its composition, such as catechin and gallocatechinThe fractions and isolated compounds obtained from CHE by bioguided fractionation are less active than the CHE against HSV-1CHE interferes with viral entry process in the host cell and acts directly on the viral particle. Abbreviations used: HSV: Herpes simplex virus, CHE: Crude hydroethanolic extract, WF: Water fraction, AF: Ethyl-acetate fraction, MPLC: Medium-performance liquid chromatography, TLC: Thin-layer chromatography, NMR: Nuclear magnetic resonance, ESI-MS: Electrospray ionization mass spectrometry, SRB: Sulforhodamine B, CPE: Cytopathic effect, CC50: 50% cytotoxic concentration, EC50: 50% effective concentration, PBS: Phosphate-buffered saline.

Cell death and ultrastructural alterations in Leishmania amazonensis caused by new compound 4-Nitrobenzaldehyde thiosemicarbazone derived from S-limonene.

BACKGROUND: The treatment of leishmaniasis with pentavalent antimonials is problematic because of their toxicity. Investigations of potentially active molecules are important to discover less toxic drugs that are viable economic alternatives for the treatment of leishmaniasis. Thiosemicarbazones are a group of molecules that are known for their wide versatility and biological activity. In the present study, we examined the antileishmania activity, mechanism of action, and biochemical alterations produced by a novel molecule, 4-nitrobenzaldehyde thiosemicarbazone (BZTS), derived from S-limonene against Leishmania amazonensis. RESULTS: BZTS inhibited the growth of the promastigote and axenic amastigote forms, with an IC50 of 3.8 and 8.0 µM, respectively. Intracellular amastigotes were inhibited by the compound with an IC50 of 7.7 µM. BZTS also had a CC50 of 88.8 µM for the macrophage strain J774A1. BZTS altered the shape, size, and ultrastructure of the parasites, including damage to mitochondria, reflected by extensive swelling and disorganization of the inner mitochondrial membrane, intense cytoplasmic vacuolization, and the presence of concentric membrane structures inside the organelle. Cytoplasmic lipid bodies, vesicles inside vacuoles in the flagellar pocket, and enlargement were also observed. BZTS did not induce alterations in the plasma membrane or increase annexin-V fluorescence intensity, indicating no phosphatidylserine exposure. However, it induced the production of mitochondrial superoxide anion radicals. CONCLUSIONS: The present results indicate that BZTS induced dramatic effects on the ultrastructure of L. amazonensis, which might be associated with mitochondrial dysfunction and oxidative damage, leading to parasite death.

Trypanocidal activity of guaianolide obtained from Tanacetum parthenium (L.) Schultz-Bip. and its combinational effect with benznidazole.

In the present study, we evaluated the in vitro antiprotozoal activity of a guaianolide (11,13-dehydrocompressanolide) isolated from Tanacetum parthenium against Trypanosoma cruzi and investigated the possible combinational effect of guaianolide and benznidazole. The isolated compound was shown to be effective against T. cruzi, with IC50 values of 18.1±0.8 and 66.6±1.3 µM against the multiplicative epimastigote and amastigote forms, respectively. The best results were obtained against trypomastigotes, with an EC50 of 5.7±0.7 µM. The guaianolide presented no toxicity in LLCMK2 cells (CC50 of 93.5 µM) and was 16.4-fold more selective for trypomastigotes. The study of the combinational effect of benznidazole and guaianolide revealed the presence of a synergistic effect against the epimastigote form and marginal additive effect against the trypomastigote form. Striking morphological changes were observed in epimastigotes treated with guaianolide, such as thinning and stretching of the cell body and flagellum and changes in the format of the cell body with apparent leakage of the cytoplasmic content in trypomastigote forms. The ultrastructural analysis of epimastigotes revealed the presence of membranes that involved organelles and formation of myelin-like figures. Flow cytometry revealed a cell volume reduction and decrease in mitochondrial membrane potential. However, no major changes in cell membrane integrity were found in the epimastigote form treated with guaianolide.

Intramuscular and topical treatment of cutaneous leishmaniasis lesions in mice infected with Leishmania amazonensis using coumarin (-) mammea A/BB.

Treatment of cutaneous leishmaniasis remains limited to a few available options. Recent studies showed in vitro antileishmanial activity of (-) mammea A/BB, a coumarin isolated from leaves of Calophyllum brasiliense. Moreover, the dichloromethane crude extract and hexane fraction from this plant demonstrated in vivo activity in mice infected with Leishmania amazonensis. We evaluated the antileishmanial activity of (-) mammea A/BB in the L. amazonensis BALB/c mice model. The animals were given intramuscular and topical treatment with (-) mammea A/BB for 30 consecutive days. The results demonstrated that 18mg/kg/d intramuscularly or 0.2% topically of (-) mammea A/BB significantly reduced the size of skin lesions in footpads of mice compared with those in the control group (p<0.05). The activity of Glucantime(®) (corresponding to 27mg/kg/d of pentavalent antimony) administered intramuscularly was similar to that of (-) mammea A/BB (p<0.05) by both routes of administration. The histopathological evaluation showed no changes in the organs analyzed. These results indicate that the coumarin obtained from C. brasiliense is the antileishmanially active compound and can be used to control the development of cutaneous leishmaniasis lesions caused by L. amazonensis.

Activity of spray-dried microparticles containing pomegranate peel extract against Candida albicans.

Pomegranate has attracted interest from researchers because of its chemical composition and biological properties. It possesses strong antioxidant activity, with potential health benefits, and also antimicrobial properties. The aim of this study was to produce microparticles containing pomegranate extract by the spray-drying technique, utilizing alginate or chitosan as encapsulating agents. Characterization and antifungal assays were carried out. Production yields were about 40% for alginate microparticles and 41% for chitosan. Mean diameters were 2.45 µm and 2.80 µm, and encapsulation efficiencies were 81.9% and 74.7% for alginate and chitosan microparticles, respectively. The spray-drying process preserved the antifungal activity against Candida albicans. These results could be useful for developing dosage forms for treating candidiasis, and should be further investigated in in vivo models.

4-Acetoxydolastane diterpene from the Brazilian brown alga Canistrocarpus cervicornis as antileishmanial agent.

Natural marine products have shown an interesting array of diverse and novel chemical structures with potent biological activities. Our study reports the antiproliferative assays of crude extracts, fraction and pure compound (4R,9S,14S)-4α-acetoxy-9ß,14α-dihydroxydolast-1(15),7-diene (1) obtained from brown alga Canistrocarpus cervicornis showing the antileishmanial activity. We showed that 1 had a dose-dependent activity during 72 h of treatment, exhibiting IC(50) of 2.0 µg/mL, 12.0 µg/mL, and 4.0 µg/mL for promastigote, axenic amastigote and intracellular amastigote forms of Leishmania amazonensis, respectively. A cytotoxicity assay showed that the action of the isolated compound 1 was 93.0 times less toxic to the macrophage than to the protozoan. Additionally, compound 1 induced ultrastructural changes, including extensive mitochondrial damage; decrease in Rh123 fluorescence, suggesting interference with the mitochondrial membrane potential; and lipid peroxidation in parasite cells. The use of 1 from C. cervicornis against L. amazonensis parasites might be of great interest as a future alternative to the development of new antileishmanial drugs.

Antimicrobial activity of Piper gaudichaudianum Kuntze and its synergism with different antibiotics.

One of the oldest forms of medical practice is the use of plants for the treatment and prevention of diseases that affect humans. We have studied the antimicrobial activity and synergism of Piper gaudichaudianum Kuntze with different antibiotics. The crude extract from the leaves of P. gaudichaudianum was submitted to chromatographic separation, resulting in five fractions. Fraction F3 contained a chromone (2,2-dimethyl-6-carboxycroman-4-one), and fraction F2 contained isomers that are prenylated derivatives of benzoic acid [4-hydroxy-(3',7'-dimethyl-1'-oxo-octa-E-2'-6'-dienyl)benzoic acid and 4-hydroxy-(3',7'-dimethyl-1'-oxo-octa-2'-Z-6'-dienyl) benzoic acid]. The chemical structures of both compounds were determined by analysis of ¹H-NMR, ¹³C-NMR, COZY, DEPT, HMQC, and HMBC spectral data, and by comparison with data in the literature. The crude extract, fraction F2, and fraction F3 showed good activity against Staphylococcus aureus, Bacillus subtilis, and Candida tropicalis. The two benzoic acid derivatives only showed activity against S. aureus and B. subtilis. The bioauthographic analysis showed an inhibition zone only in fraction F2. Fractions F2 and F3 showed synergism in combination with ceftriaxone, tetracycline, and vancomycin. Morphological changes in form and structure were found by scanning electron microscopy in S. aureus treated with the combination of fraction F2 with vancomycin.

Trypanocidal activity of oxoaporphine and pyrimidine-ß-carboline alkaloids from the branches of Annona foetida Mart. (Annonaceae).

Phytochemical investigation of the branches of Annona foetida Mart. led to isolation from the CH(2)Cl(2) extract of four alkaloids: Atherospermidine (1), described for the first time in this species, liriodenine (2), O-methylmoschatoline (3), and annomontine (4). Their chemical structures were established on the basis of spectroscopic data from IR, MS, NMR (1D and 2D), and comparison with the literature. Compounds 2-4 showed potent trypanocidal effect when evaluated against epimastigote and trypomastigote forms of Trypanosoma cruzi.

Thiophene derivatives with antileishmanial activity isolated from aerial parts of Porophyllum ruderale (Jacq.) Cass.

Porophyllum ruderale (Jacq.) Cass. is a plant native to Brazil and in the northwest region of the state of Paraná, Brazil, aerial parts of P. ruderale have been used popularly in the treatment of lesions caused by Leishmania sp.. In this study the antileishmanial and cytotoxic activities of the crude extract, fractions, and isolated compounds from aerial parts of P. ruderale was evaluated. The dichloromethane extract was submitted to chromatography to yield compounds active against Leishmania amazonensis. Their structures were established by comparison of their spectroscopic data with literature values. The activities of crude extract against promastigote and axenic amastigote forms of L. amazonensis (IC(50)) were 60.3 and 77.7 µg/mL, respectively. Its cytotoxic activity against macrophage cells (CC(50)) was 500 µg/mL. The thiophene derivatives isolated were: 5-methyl-2,2':5',2"-terthiophene (compound A) and 5'-methyl-[5-(4-acetoxy-1-butynyl)]-2,2'-bithiophene (compound B). The activity of compound A against promastigote and axenic amastigote forms were 7.7 and 19.0 µg/mL and of compound B were 21.3 and 28.7 µg/mL, respectively. The activity of the isolated compounds against promastigote and axenic amastigote forms was better than that of the crude extract and more selective against protozoa than for macrophage cells.

Antifungal effects of Ellagitannin isolated from leaves of Ocotea odorifera (Lauraceae).

Ocotea odorifera is a medicinal plant that is popularly known in Brazil as "canela-sassafrás" and is used to treat dermatosis. This study investigated the antifungal properties of O. odorifera. The methanol extract of O. odorifera was submitted to successive chromatographic separation and yielded Tellimagrandin II (TEL). Candida parapsilosis strain ATCC 22019 was used to determine the minimum inhibitory (MIC) and fungicidal concentrations, and to study the synergistic action with nystatin (NYS), amphotericin (AMP), and fluconazole (FLU). After treatment, the morphology of the yeast was analysed by scanning electron microscopy. Cytotoxicity was assessed in Vero cells, and genotoxicity by the micronucleus test. The TEL structure was proposed based on NMR and comparison with literature data and ESI-MSMS analysis. The compound showed potent inhibitory activity against C. parapsilosis, with a MIC of 1.6 µM. TEL acted synergistically with NYS, AMP, and FLU, and caused morphological alterations in the yeast cells. The methanolic extract showed low cytotoxicity in vitro and in vivo, and was not mutagenic in mice (P < 0.05). The use of O. odorifera in traditional medicine seems to have a valid basis, in view of the antifungal activity of TEL demonstrated in this study, and may contribute to potential drug development.

Effect of elatol, isolated from red seaweed Laurencia dendroidea, on Leishmania amazonensis.

In the present study, we investigated the antileishmanial activity of sesquiterpene elatol, the major constituent of the Brazilian red seaweed Laurencia dendroidea (Hudson) J.V. Lamouroux, against L. amazonensis. Elatol after 72 h of treatment, showed an IC(50) of 4.0 µM and 0.45 µM for promastigote and intracellular amastigote forms of L. amazonensis, respectively. By scanning and transmission electron microscopy, parasites treated with elatol revealed notable changes compared with control cells, including: pronounced swelling of the mitochondrion; appearance of concentric membrane structures inside the organelle; destabilization of the plasma membrane; and formation of membrane structures, apparently an extension of the endoplasmic reticulum, which is suggestive of an autophagic process. A cytotoxicity assay showed that the action of the isolated compound is more specific for protozoa, and it is not toxic to macrophages. Our studies indicated that elatol is a potent antiproliferative agent against promastigote and intracellular amastigote forms, and may have important advantages for the development of new anti-leishamanial chemotherapies.

In vitro antifungal activity of the berberine and its synergism with fluconazole.

Berberine with and without fluconazole was tested by an agar disk diffusion assay in which clinical isolates of Candida albicans were applied onto yeast extract-peptone-dextrose agar plate. Berberine, which had no intrinsic antifungal activity at the concentration tested, exerted a powerful antifungal activity in combination of fluzonazole. Combinations of berberine and fluconazole were also tested by the checkerboard assay to determine whether they had favorable or unfavorable antifungal interactions. The MIC of fluconazole was 1.9 microg/ml when the drug was tested alone and decreased to 0.48 microg/ml in the presence of berberine concentrations of 1.9 microg/ml. However, berberine at concentrations of >1.9 microg/ml combined with a fluconazole supra-MIC (i.e., >1.9 microg/ml) eliminated the residual turbidity in the incubation wells. This endpoint fitted to the definition of MIC-0 (optically clear wells) and reflected the absence of a trailing effect, which is the result of a residual growth at fluconazole concentrations greater than the MIC.

Chemical Composition and Antimicrobial Properties of Piper ovatum Vahl.

The chemical composition of the essential oil obtained from the leaves of Piperovatum Vahl by hydrodistillation was analyzed by GC-MS. The main constituents found were delta-amorphene (16.5 %), cis-muurola-4(14),5-diene (14.29 %) and gamma-muurolene(13.26%). The crude extracts and isolated compounds were screened for their antimicrobial activity. Hydroalcoholic extracts of different parts of Piper ovatum Vahl, essential oil andamides isolated from leaves were tested against Gram-positive and Gram-negative bacteria and Candida species. All extracts and amides were active against Bacillus subtilis andCandida tropicalis, including clinical strains. Essential oil was active against C. tropicalis.These amides showed an inhibitory effect on the adherence of C. tropicalis ATCC 28707 on cover glasses at 10 microg/mL, but did not show morphological alterations at the tested concentrations. Amides were identified as piperovatine and piperlonguminine, and showed MIC values of 15.6 and 31.2 microg/mL to B. subtilis and 3.9 microg/mL to C. tropicalis, and low toxic effects to Vero cells and macrophages.

Characterisation of potential virulence markers in Pseudomonas aeruginosa isolated from drinking water.

Pseudomonas aeruginosa isolates from tap water, mineral water, and artesian well water were investigated for their ability to produce different potential virulence factors or markers such as hemolysins, hemaglutinins, cytotoxins and their ability to adhere to epithelial cells and to abiotic surfaces. The susceptibility to antibiotics, human serum sensitivity and the survival of P. aeruginosa isolates in a chlorinated environment were also examined. Of the 30 isolates tested, 16 possessed the capacity to adhere to abiotic surfaces, and 28 to adhere to epithelial cells; 30 were capable of producing hemolysins, 27 produced cytotoxins, 9 hemagglutinins, and 18 were classified as serum-resistant. For the lowest concentration of chlorine (0.2 mg/l) tested, no killing of biofilm bacteria could be discerned, even after prolonged exposure to the agent. Although all the drinking water isolates were susceptible to aztreonam, cefepime, ceftazidime, ciprofloxacin, imipenem, meropenem, piperacillin-tazobactam, and polymyxin, the P. aeruginosa isolates were resistant to one or more antibiotics. The increasing prevalence of resistance in the isolates from environmental sources may have important therapeutic implications. A notable proportion of the P. aeruginosa isolates from drinking water were able to develop virulence factors, and the incidence of virulence properties was not statistically different among the three sources. A more extensive study of the virulence properties of this bacterium by toxic assays on animals should be explored. Still more interesting would be toxicity assays on immuno-deficient animals with isolates from drinking water in order to better understand the health risk these bacteria may present.

Trypanosoma cruzi: antiprotozoal activity of parthenolide obtained from Tanacetum parthenium (L.) Schultz Bip. (Asteraceae, Compositae) against epimastigote and amastigote forms.

This study reports the activity of crude extracts, fractions and parthenolide (pure compound) obtained from Tanacetum parthenium against two forms of the parasite Trypanosoma cruzi. Feverfew is a traditional herbal medicine that has been used for the treatment of migraine, fever and arthritis. Activity against epimastigote forms was observed for crude extracts, fractions and parthenolide, and a progressive increase in the antitrypanosomal effect was observed in the course of the purification process. The pure compound showed IC50/96h and IC90/96h of 0.5 microg/ml and 1.25 microg/ml, respectively. The cytotoxic effect of parthenolide in LLMCK2 cells was 3.2 microg/ml (CC50/96h) and the selectivity index was 6.4. No hemolysis was detected for the pure compound. The internalization index of T. cruzi in LLMCK2 cells was reduced almost 51% at the concentration of 2 microg/ml of parthenolide, and 96.6% at 4 microg/ml. Scanning and transmission electron microscopy permitted observation of morphological modifications and ultrastructural alterations.