Cladonia verticillaris (lichen) indicates negative impacts derived from the combustion of biodiesel blends: an alert for the environmental management for biofuels use.

The use of biodiesel blends with petroleum diesel in vehicular engines demands the evaluation of the possible impacts and effects of the gases emitted from their combustion on the environment. Among studies on these questions, biomonitoring using lichens is a viable alternative, given their interactions with the elements dispersed in the atmosphere, as well as its sensitivity and capacity to retain contaminants. In this study, we analyzed the effects of gas emissions from the combustion of biodiesel mixture with petroleum diesel on Cladonia verticillaris thalli. Samples of the lichen (10 g) were exposed to the gases emitted by the exhaust of the generator engine during the combustion process of biodiesel mixtures to petroleum diesel (7% (B7), 10% (B10), 40% (B40), 50% (B50), and 70% (B70)). At 90 days after exposure, samples were analyzed for n-alkane profiles, thallus morphology, photosynthetic pigment contents, and secondary lichen metabolites (protocetraric and fumarprotocetraric acids). Sets B7 and B10 showed better resistance of the lichen to pollutants. Set B40 showed a high stress evidenced by the chain elongation of n-alkanes structure and high chlorophyll production, presenting high morphological damages when compared to the control sets, B7 and B10. The results showed significant reductions of n-alkanes profiles for mixtures with high concentrations of biodiesel (B50 and B70), as well as decreases in the chlorophyll content. These groups showed an increase in the synthesis of secondary metabolites, corroborating the hypothesis that high concentrations of biodiesel in the mixture with petroleum diesel have greater impacts on the lichen. Schematic model for demonstration of using the lichen Cladonia verticillaris as biomonitor of effects from gas emissions from the combustion of biodiesel blends with petroleum diesel by a stationary engine.

Schistosomicidal effect of divaricatic acid from Canoparmelia texana (Lichen): In vitro evaluation and ultrastructural analysis against adult worms of Schistosoma mansoni.

In this study we evaluated the in vitro effect of divaricatic acid against coupled worms of Schistosoma mansoni. The schistosomicidal effect was evaluated through the bioassay of motility and mortality, cellular viability of the worms and ultrastructural analysis through Scanning Electron Microscopy. To evaluate the cytotoxicity of divaricatic acid, a cell viability assay was performed with human peripheral blood mononuclear cells. Divaricatic acid proved effect against S. mansoni after 3 hours of exposure. At the end of 24 h the concentrations of 100 - 200 µM presented lethality to the worms. Motility changes were observed at sublethal concentrations. The IC50 obtained by the cell viability assay for S. mansoni was 100.6 µM (96.24 - 105.2 µM). Extensive damage to the worm's tegument was observed such as peeling, erosion, bubbles, edema, damage and loss of tubercles and spines, fissures and tissue ruptures. No cytotoxicity was observed in human peripheral blood mononuclear cells. This report provides data showing the schistosomicidal effect of divaricatic acid on S. mansoni, causing death, motile changes and ultrastructural damage to worms. In addition, divaricatic acid was shown to be non-toxic to human peripheral blood mononuclear cells at concentrations effective on S. mansoni.

Sublethal concentrations of usnic acid potassium salt impairs physiological parameters of Biomphalaria glabrata (Say, 1818) (Pulmonata: Planorbidae) infected and not infected with Schistosoma mansoni.

Schistosomiasis is a public health problem in many developing countries. The mollusc Biomphalaria glabrata is the most important vector of Schistosoma mansoni in South America. The population control of this vector to prevent the spread of schistosomiasis is currently done with the application of highly toxic molluscicide to the environment. The screening of substances in sublethal concentrations that have deleterious effects on physiological parameters is very relevant for the control of schistosomiasis, since the effectiveness of disease prevention increases if it acts on population control of the vector and on reproduction and elimination in S. mansoni cercariae. The objective of this study was to evaluate the reproductive parameters (fecundity and fertility), intra-mollusk effect (sporocysts I (72 h) and II (14 days after)) on the development of cercariae of S. mansoni and the immune cell profile of B. glabrata exposed to sublethal concentrations (LC25 - 0.5 µg/mL and LC50 - 0.92 µg/mL) of the usnic acid potassium salt (potassium usnate). LC 25 and LC 50 significantly reduced (p < 0.05) the fecundity of B. glabrata when treated infected and/or not exposed to infection, while unviable embryos were not observed in sporocyst stage I, being only significant (p < 0.05) for mollusks infected and treated with LC50 on sporocyst II. LC25 and LC50 of the potassium usnate caused significant reductions (p < 0.05) in the production and cercarial shedding when evaluated on sporocysts I and II. In addition, the mortality of infected and treated B. glabrata in the sporocyst II phase was quite marked after the 9th week of infection. Regarding the immunological cell profile of uninfected B. glabrata, both concentrations led to immunomodulatory responses, with significant morphological changes predominant of hemocytes that entered programmed cell death (apoptosis). It was concluded that the application of LC25 and LC50 from the potassium usnate could be useful in the population control of B. glabrata, since it interferes both in their biology and physiology and in the reproduction of the infectious agent of schistosomiasis mansoni.

In vitro activity of usnic acid potassium salt against different developmental stages of Schistosoma mansoni: An ultrastructural study.

Currently, the control of schistosomiasis is based on a single drug, praziquantel, which is effective against all species of Schistosoma but only in the adult stage, presenting a schistosomicidal deficit at the other developmental stages of the parasites. Recently our research group has demonstrated that the potassium salt of usnic acid (PS-UA) presented schistosomicidal property against couples of adult worms of S. mansoni. Thus, the present study seeks to report for the first time the in vitro activity of PS-UA against different developmental stages of S. mansoni (schistosomules and young worms). As schistosomicide parameters, we evaluated motility, mortality, cell viability of the worms and tegument changes by scanning electron microscopy (SEM). After 3 h exposure, PS-UA was lethal to schistosomules at concentrations of 100 and 50 µM, whereas for concentrations 25 and 12.5 µM, 38 and 18% of mortality and 62 and 24% changes in motility, respectively, were reached. Yet for schistosomules, concentration of 25 µM caused 90 and 100% of death after 6 and 12 h, respectively. In the concentration of 12.5 µM at intervals of 12 and 24 h mortality was 68 and 100%, respectively. For young worms, after 3 h of exposure at concentrations of 200 and 100 µM caused 57 and 27% mortality, respectively. After 12 and 24 h, these concentrations caused mortality of 90 and 100% and 47 and 60% respectively. After 24 h, concentrations of 50 and 25 µM caused 80 and 30% change in motility, respectively. However, at the 12.5 µM concentration no change was observed. In addition, PS-UA reduced the cellular viability of young worms by 50.98% and 85.87% at concentrations of 100 and 200 µM, respectively. In both stages of worms and at different exposure intervals, PS-UA caused alterations such as: dorsoventral contraction, peeling, swelling, blisters, erosion, exposure of subtegumental tissue and disintegration of tegument. According to the results, changes in motility and mortality caused by PS-UA against schistosomules and young worms were concentration and time-dependents, also PS-UA even at low concentration, was able to cause profound ultrastructural changes in the integument of the worms. PS-UA is a promising candidate as prophylactic agent in the control of schistosomiasis mansoni.

Potassium usnate, a water-soluble usnic acid salt, shows enhanced activity against Schistosoma mansoni in vitro.

Here, we report enhanced the in vitro effect of potassium usnate on coupled adult Schistosoma mansoni worms at different time intervals and concentrations. The evaluated schistosomicidal parameters were the following: motility, mortality, fecundity and integumentary changes, as viewed in photomicrographs. Potassium usnate was able to cause 100 and 50% mortality at 100 and 50 µM concentrations, respectively, after 24 h of exposure, while 25 and 12.5 µM concentrations caused changes in motility at 48 and 72 h, and lethality at 96 and 120 h respectively. Eggs were not detected at any of the concentrations analyzed. Photomicrographs revealed morphological tegument alterations within all periods of observation, such as swelling, blisters, dorsoventral contraction, short and curved worms. In conclusion, our results indicate that potassium usnate represents a possible candidate for a new drug in the control of schistosomiasis.

Usnic Acid Potassium Salt: Evaluation of the Acute Toxicity and Antinociceptive Effect in Murine Model.

To obtain usnic acid potassium salt (PS-UA), the usnic acid (UA) was extracted and purified from the lichen Cladonia substellata, and modified to produce PS-UA. The structure was determined by 1H-NMR, IR and elemental analysis, ratified through computational models, as well as identification the site of K+ insertion in the molecule. Antinociceptive activity was detected through contortions in mice induced by acetic acid and formalin (phases I and II) after treatments with 10 and 20 mg/kg of PS-UA, indicating interference in both non-inflammatory and inflammatory pain. After oral administration at doses of 500, 1000 and 2000 mg/kg, no deaths of mice with treatments below 2000 mg/kg were observed. Except for body weight gain, food and water consumption decreased with treatments of 1000 and 2000 mg/kg, and the number of segmented leukocytes was higher for both treatments. Regarding serum levels, cholesterol and triglycerides decreased, however, there was an increase in hepatic transaminases with both treatments. Liver and kidney histological changes were detected in treatments of 2000 mg/kg, while the spleen was preserved. The PS-UA demonstrated antinociceptive activity while the acute toxicity at the concentration of 2000 mg/kg was the only dose that presented morphological changes in the liver and kidney.

Usnic acid potassium salt from Cladonia substellata (Lichen): Synthesis, cytotoxicity and in vitro anthelmintic activity and ultrastructural analysis against adult worms of Schistosoma mansoni.

We report for the first time the in vitro effect of Potassium Salt, derived from Usnic Acid (PS-UA), isolated from the lichen Cladonia substellata Vanio, on couples of Schistosoma mansoni. As schistosomicide parameters, we evaluated mortality, motility, cell viability of the worms and tegument changes by scanning electron microscopy (SEM). Exposure to a concentration of 100 µM caused 75% mortality after 3 h. After 6 h, changes in motility in concentrations of 50 and 25 µM are evidenced. After 12 h and 24h, the concentrations of 50 and 100 µM caused 6.25% and 87.5% and 50% and 100% mortality, respectively. PS-UA reduced the cell viability of the worms by 27.36% and 52.82% at concentrations 50 and 100 µM, respectively. Through SEM we observed progressive dose-and time-dependent, alterations such as swelling, blisters, dorsoventral contraction, erosion until disintegration of the tubercles in the tegument of male and female. PS-UA did not alter the viability of human peripheral blood mononuclear cells and showed high selectivity indices (IC50 > 200 µM). Our results indicate that PS-UA represents a possible candidate for a new anthelmintic drug in the control of schistosomiasis.

Phytochemical and biological evaluation of metabolites produced by alginate-immobilized Bionts isolated from the lichen Cladonia substellata vain.

In this work, new biotechnological procedures have been optimized on the basis of immobilization in alginate of bionts isolated from the lichen C. substellata. From these immobilizates, soluble and biologically active phenolics can be obtained. During bionts-immobilization, stictic, norstictic and usnic acids were secreted to the medium. The amount produced of each of them differed depending on the immobilization time, the precursor supplied and the type of biont used. Greater amounts of stictic acid were detected and maintained over time in all bioreactors. The opposite occurs in non-immobilized thallus. Virtually, all lichen phenols exhibit antioxidant activity to a greater or lesser degree, so that the antioxidant capacity of stictic acid (82.13% oxidation inhibition) was tested. The soluble extract of immobilized algae co-incubated in sodium acetate with fungal hyphae contained carbohydrates and exhibited a potent antioxidant capacity after 13 days of immobilization (94.87%). Therefore, attempts have been made to relate both parameters. On the other hand, the growth of Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae was inhibited by phenolic compounds produced by immobilizates, although the organic extract of the whole lichen showed the highest activity due to a possible synergy with other indeterminate compounds. Thus, C. substellata immobilized bionts are a potential source of different natural antioxidant and antimicrobial compounds.

Potassium usnate toxicity against embryonic stages of the snail Biomphalaria glabrata and Schistosoma mansoni cercariae.

The snail Biomphalaria glabrata is the most important vector for Schistosoma mansoni. Control of this vector to prevent the spread of schistosomiasis is currently performed with the application of a niclosamide molluscicide, which is highly toxic to the environment. Screening of substances that show embryotoxic molluscicidal potential as well as have detrimental effects on cercariae is very relevant for the control of schistosomiasis, as the efficacy of prevention of the disease is increased if it acts as a molluscicide as well as on the cercariae of S. mansoni. The aim of this work was to evaluate the effect of potassium usnate derived from usnic acid on different stages of embryonic development of B. glabrata and on S. mansoni cercariae. After 24 h of exposure, potassium usnate showed embryotoxic activity across all embryonic stages. The values obtained from the LC50 for the embryonic stages were the following: blastula 5.22 µg/mL, gastrula 3.21 µg/mL, trochophore 3.58 µg/mL, veliger 2.79, and hippo stage 2.52 µg/mL. Against S. mansoni cercariae, it had LC90 and 100% mortality at concentrations of 2.5 and 5 µg/mL in 2 h of exposure. In conclusion, this is the first report of potassium usnate toxicity on the embryonic stages of B. glabrata and cercariae of S. mansoni, and this study shows the potassium usnate as a promising agent for the control of mansoni schistosomiasis.

Indigofera suffruticosa Mill. (Anil): Plant Profile, Phytochemistry, and Pharmacology Review.

Indigoferasuffruticosa Mill. (Fabaceae) is known as anil or anileira and also with other names, due to the production of a blue pigment, which is commonly used for yarn dyeing. It is distributed in some states of Brazil (Pernambuco, Paraíba, Mato Grosso, São Paulo, Bahia, Pará, and others) and is used in the popular medicine as a febrifuge, antispasmodic, diuretic, abortive, analgesic, purgative, or soothing agent against stomach and urinary problems, jaundice, and ulcers and also as an insecticide. In addition, I. suffruticosa can be used as animal feed. This review aimed at providing important data on the botanical, distribution, ethnopharmacology, phytochemical, pharmacological, and toxicity of I. suffruticosa based on the scientific literature. Information on I. suffruticosa was gathered via the Internet (from Elsevier, NCBI, and Sci-Hub) and libraries in the period from February to March 2016. More than 40 chemical compounds have been identified and a few compounds isolated, and the main origins are the essential oils, organic extracts, and aqueous extracts of different parts of the plant. I. suffruticosa and its active compounds possess wide pharmacological actions in the literature, such as anti-inflammatory, antibacterial, antifungal, antioxidative, antitumor, antimutagenic, anticonvulsant, gastroprotective, and hepatoprotective activities. Therefore, as an important traditional popular medicine, further studies on I. suffruticosa are required for the development of new drugs and therapeutics for various diseases.

Toxicity of Usnic Acid from Cladonia substellata (Lichen) to embryos and adults of Biomphalaria glabrata.

This study reports the molluscicidal activity of usnic acid isolated from Cladonia substellata Vanio (lichen) on embryos at various stages of development and in adult mollusks of Biomphalaria glabrata. The toxicity of usnic acid was also evaluated through Artemia salina larvae mortality. Usnic acid was extracted with diethyl ether, isolated, purified, and its structure confirmed by analyzing the spectra of proton nuclear magnetic resonance. LC90 for 24 h of exposure were 1.62, 4.45, 5.36, and 4.49 µg mL-1 for blastula, gastrula, trocophore, and veliger embryonic stages, respectively, and 3.45 µg mL-1 for adult snails; LC50 of usnic acid against A. salina was 2.46 µg mL-1. LC90 assessed 7 days after exposure was 2.56 µg mL-1 for adult mollusks. In conclusion, these findings demonstrate that under laboratory conditions usnic acid has teratogenic and molluscicide potential to control the aquatic snail B. glabrata and may prove to be a promising candidate in the search for new molluscicide agents, but further detailed studies on its molluscicidal effect and possible environmental effects are needed.

Hepatic toxicity caused by PLGA-microspheres containing usnic acid from the lichen C ladonia substellata (AHTI) during pregnancy in Wistar rats.

This study aimed to evaluate the teratogenic and hepatotoxic potential of the usnic acid encapsulated into PLGA-microspheres. In total, 12 female Wistar rats in pregnancy were randomly distributed in the control group (n= 6) that received 1.0 mL of physiological solution and treatment group (n= 6) that received 25 mg/kg of encapsulated usnic acid by oral administration. All females were euthanized at day 20 of pregnancy and their fetuses were removed and analyzed. During the pregnancy was observed a reduction in weight gain. There was no difference in serum transaminases levels analyzed as well as any difference in liver weight in both groups. The histomorphometric analysis of the liver from the treatment group revealed an increase in number of hepatocytes and a decrease in nuclear area of these cells. Moreover, no alteration was observed in cell area of hepatocytes or number of Kupffer cells. The fetuses had an increase in total number of hepatocytes and a reduction in the amount of megakaryocytes. These results show the hepatotoxic potential of usnic acid during pregnancy. However, its toxicity can be minimized by encapsulation in microspheres.

Hepatic toxicity caused by PLGA-microspheres containing usnic acid from the lichen C ladonia substellata (AHTI) during pregnancy in Wistar rats

ABSTRACT This study aimed to evaluate the teratogenic and hepatotoxic potential of the usnic acid encapsulated into PLGA-microspheres. In total, 12 female Wistar rats in pregnancy were randomly distributed in the control group (n= 6) that received 1.0 mL of physiological solution and treatment group (n= 6) that received 25 mg/kg of encapsulated usnic acid by oral administration. All females were euthanized at day 20 of pregnancy and their fetuses were removed and analyzed. During the pregnancy was observed a reduction in weight gain. There was no difference in serum transaminases levels analyzed as well as any difference in liver weight in both groups. The histomorphometric analysis of the liver from the treatment group revealed an increase in number of hepatocytes and a decrease in nuclear area of these cells. Moreover, no alteration was observed in cell area of hepatocytes or number of Kupffer cells. The fetuses had an increase in total number of hepatocytes and a reduction in the amount of megakaryocytes. These results show the hepatotoxic potential of usnic acid during pregnancy. However, its toxicity can be minimized by encapsulation in microspheres.

Molecular modeling and cytotoxicity of diffractaic acid: HP-ß-CD inclusion complex encapsulated in microspheres.

In this pioneer study, 2-hydroxypropyl-ß-cyclodextrin (HP-ß-CD) was used to improve the solubility of the diffractaic acid (DA) via inclusion complex (DA:HP-ß-CD). Subsequently, DA:HP-ß-CD was incorporated into poly-ε-caprolactone (PCL) microspheres (DA:HP-ß-CD-MS). Microspheres containing DA (DA-MS) or DA:HP-ß-CD (DA:HP-ß-CD-MS) were prepared using the multiple W/O/W emulsion-solvent evaporation technique. The phase-solubility diagram of DA in HP-ß-CD (10-50mM) showed an AL type curve with a stability constant K1:1=821M-1. 1H NMR, FTIR, X-ray diffraction and thermal analysis showed changes in the molecular environment of DA in DA:HP-ß-CD. The molecular modeling approach suggests a guest-host complex formation between the carboxylic moiety of both DA and the host (HP-ß-CD). The mean particle size of the microspheres were ∅DA-MS=5.23±1.65µm and ∅DA:HP-ß-CD-MS=4.11±1.39µm, respectively. The zeta potential values of the microspheres were ζDA-MS=-7.85±0.32mV and ζDA:HP-ß-CD-MS=-6.93±0.46mV. Moreover, the encapsulation of DA:HP-ß-CD into microspheres resulted in a more slower release (k2=0.042±0.001; r2=0.996) when compared with DA-MS (k2=0.183±0.005; r2=0.996). The encapsulation of DA or DA:HP-ß-CD into microspheres reduced the cytotoxicity of DA (IC50=43.29µM) against Vero cells (IC50 of DA-MS=108.48µM and IC50 of DA:HP-ß-CD-MS=142.63µM).

Bactericidal Activity of Usnic Acid-Loaded Electrospun Fibers.

BACKGROUND: Usnic acid has been progressively reported in the literature as one of the most important lichen metabolites characterized by a rich diversity of applications such as antifungal, antimicrobial, antiprotozoal and antiviral agent. Particularly, antimicrobial activity of usnic acid can be improved by encapsulation of active molecules in enteric electrospun fibers, allowing the controlled release of active molecule at specific pH. Few relevant patents to the topic have been reviewed and cited. METHODS: Bactericidal activity of usnic acid-loaded electrospun fibers of Eudragit L-100 and polyvinylpyrrolidone was examined against Staphylococcus aureus using inhibition hales methodology. RESULTS: The controlled release of active material at high pH is established after 10 minutes of interaction with media and results in reasonable activity against S. aureus, as detected by inhibition hales. CONCLUSION: The strong biological activity of usnic acid-loaded electrospun fibers provides a promising application for corresponding material as a bactericidal agent for wound healing treatment.

Ultrastructural analysis of Leishmania infantum chagasi promastigotes forms treated in vitro with usnic acid.

Leishmaniasis is considered by the World Health Organization as one of the infectious parasitic diseases endemic of great relevance and a global public health problem. Pentavalent antimonials used for treatment of this disease are limited and new phytochemicals emerge as an alternative to existing treatments, due to the low toxicity and cost reduction. Usnic acid is uniquely found in lichens and is especially abundant in genera such as Alectoria, Cladonia, Evernia, Lecanora, Ramalina, and Usnea. Usnic acid has been shown to exhibit antiviral, antiprotozoal, antiproliferative, anti-inflammatory, and analgesic activity. The aim of this study was to evaluate the antileishmanial activity of usnic acid on Leishmania infantum chagasi promastigotes and the occurrence of drug-induced ultrastructural damage in the parasite. Usnic acid was effective against the promastigote forms (IC50=18.30±2.00 µg/mL). Structural and ultrastructural aspects of parasite were analyzed. Morphological alterations were observed as blebs in cell membrane and shapes given off, increasing the number of cytoplasmic vacuoles, and cellular and mitochondrial swelling, with loss of cell polarity. We concluded that the usnic acid presented antileishmanial activity against promastigote forms of Leishmania infantum chagasi and structural and ultrastructural analysis reinforces its cytotoxicity. Further, in vitro studies are warranted to further evaluate this potential.

Determination of Teloschistes flavicans (sw) norm anti-inflammatory activity.

BACKGROUND: Lichens produce a variety of substances that possesses pharmacological actions. However, rare products are submitted to rigorous scientific tests or have the risk potential or side effects evaluated. The lack of medical and sanitary control, absence of accurate botanical identification or purity certification, founded in diverse natural products, may represent great danger to population health. This work aimed to evaluate toxic effects and anti-inflammatory action in vivo of Teloschistes flavicans (Sw.) Norm. (TFN) unrefined extracts, as well as determinate its main constituents. METHODS: The carrageenan induced paw edema and cotton pellet implant induced granuloma methods were utilized, besides a classic acute toxicity test. TFN acetone extract inhibited carrageenan paw edema on 60, 120, and 180 min (inhibition percentiles of 45.03%, 60.59% and 41.72%). RESULTS: TFN ethereal (inhibition percentiles of 23.95% and 29.01%) and chloroform (inhibition percentiles of 28.8% and 22.04%) extracts inhibited edema on 120 and 180 min. None of the extract inhibited the granuloma development. None of the extract caused death or other acute toxicity signs. Vicanicine (60.26% in ethereal extract and 51.17% in acetone extract), parietine (9.60% in ethereal extract and 15.38% on second), falacinol (0.78% in ether and 14.95% in acetone) and very low concentration of falacinal (0.15% in ethereal extract and 3.32% in acetone extract) were detected in the medicine. CONCLUSIONS: The tested extracts have antiedematogenic activity, but are not effective on subchronic inflammation. The extracts do not present toxic effects in administered doses.

Effects of essential oils from Cymbopogon citratus (DC) Stapf., Lippia sidoides Cham., and Ocimum gratissimum L. on growth and ultrastructure of Leishmania chagasi promastigotes.

The current therapy for leishmaniasis, which affects annually about 2 million people, is far from satisfactory. All available drugs require parenteral administration and are potentially toxic. Plant essential oils have been traditionally used in folk medicine and appear as valuable alternative source for chemotherapeutic compounds. In this study, we demonstrated the effect of essential oils from Cymbopogon citratus, Lippia sidoides, and Ocimum gratissimum on growth and ultrastructure of Leishmania chagasi promastigote forms. Steam distillation was used to isolate the essential oils, and their constituents were characterized by gas chromatography coupled to mass spectrometry and nuclear magnetic resonance. All essential oils showed in vitro inhibitory action on L. chagasi promastigotes growth in a dose-dependent way, with IC(50)/72 h of 45, 89, and 75 microg/mL for C. citratus, L. sidoides, and O. gratissimum, respectively. Drastic morphological alterations were observed in all essential oil-treated parasites, including cell swelling, accumulation of lipid droplets in the cytoplasm, and increase of acidocalcisome volume. Furthermore, aberrant-shaped cells with multi-septate body were observed by scanning electron microscopy, suggesting an additional effect on cytokinesis. Taken together, our data show that these essential oils affect the parasite viability being the C. citratus essential oil the most effective against L. chagasi.

Plasmodium immobilization of Physarella oblonga (Berk. & Curt.) Morgan (Myxomycetes) using kaolinite as a matrix of entrapment.

The possibility of using kaolinite-immobilized plasmodium fragments of Physarella oblonga (Berk. & Curt.) Morgan to maintain their metabolic activity was examined. The immobilization process was carried out with 1 mg of plasmodium of P. oblonga entrapped in 10 g of kaolinite. Sodium acetate (1 mM) was used as a metabolic precursor. The collection of fractions was carried out during a one month period, and extracted with ether/ethyl acetate and chloroform/acetonitrile. The extractions from plasmodium in natura were accomplished with the same solvents. The extracts obtained were analyzed in a spectrophotometer at 266 nm and 310 nm, and by thin layer chromatography to assess the productivity of the immobilized plasmodium. The absorbances of the extracts in both wavelengths and the chromatographic tests showed the synthesis of compounds by the immobilized material. Three chromatographic spots were observed in the extracts obtained from the immobilized plasmodium. Two spots coincided with the R(f) values and coloration of the spots observed for the material in natura used as a reference. The kaolinite-immobilized plasmodium of P. oblonga can remain metabolically active for at least one month at room temperature and ambient light conditions.

Detecção de atividade antibacteriana in vitro nos extratos brutos obtidos a partir do plasmódio de Physarella oblonga (Berk. & Curt.) Morgan (Myxomycetes)

Utilizando-se o teste de difusão em meio sólido, detectou-se atividade antibacteriana em extratos de Physarella oblonga (Physaraceae) obtidos a partir de imobilização plasmodial e do plasmódio in natura. Os extratos foram ativos contra Staphylococcus aureus (halos=14 mmf) e Mycobacterium smegmatis (halos=12 mmf e 13 mmf). Menor inibição foi observada frente a Bacillus subtilis (halos=10 mmf e 9 mmf) e Pseudomonas aeruginosa (halos=10 mmf e 8 mmf). Escherichia coli apresentou resistência a todos os extratos testados. O cromatograma evidenciou semelhanças na composição química dos extratos, justificando as similaridades no potencial inibitório de ambos, sendo as substâncias com Rf 0,91 e 0,82, presentes em ambas as amostras, os prováveis inibidores do crescimento bacteriano.

Diffusion solid medium test was used to detect antibacterial activity in Physarella oblonga (Physaraceae) extracts obtained from plasmodial immobilization and in natura plasmodium. The extracts presented activity against Staphylococcus aureus (halos=14 mmf) and Mycobacterium smegmatis (halos=12 mmf e 13 mmf). Slower inhibition was obtained against Bacillus subtilis (halos=10 mmf e 9 mmf) and Pseudomonas aeruginosa (halos=10 mmf e 8 mmf). Escherichia coli presented resistence to all tested extracts. The chromatogram revealed likeness in the chemical composition of the extracts, explaining similarities in inhibitory potential. The substances with Rf 0,91 and 0,82, present in both extracts, could be inhibitor agents of bacterial growth.