Promising synergistic activity of fluconazole with bioactive Guttiferone-A and derivatives against non-albicans Candida species.

Natural products with diverse bioactivities and structures are an important source of novel chemicals with pharmaceutical potentials. Combinations of bioactive compounds with classical antimicrobial agents against drug-resistant or low-susceptible Candida spp. have been studied. Guttiferone-A and its derivatives were combined with fluconazole through the checkerboard method and tested against Candida spp. The results obtained, especially the Fractional Inhibitory Concentration Index (FICI) determined to the combinations, suggests promising results on the treatment of Candida infections, principally for species that present resistance or low antifungal susceptibility. The best result was seen for C. krusei, in which a synergic action of the association between fluconazole and Guttiferone-A resulted in a reduction of more than 100-fold in the alone inhibitory concentration (MIC) of fluconazole. Synergism was also noted in the association of fluconazole with the synthetic derivatives LFQM-79, LFQM-80 and LFQM-81 against C. glabrata, with reduction of up to four times in the alone IC of fluconazole. These results suggest the possibility of combined administration with reduction of doses and side effects of drugs conventionally used against Candida spp. and the promising therapeutic action of Guttiferone-A.

Toxic effects of two essential oils and their constituents on the mealworm beetle, Tenebrio molitor.

The study identified insecticidal effects from the cinnamon and clove essential oils in Tenebrio molitor L. (Coleoptera: Tenebrionidae). The lethal concentrations (LC50 and LC90), lethal time, and repellent effect on larvae, pupae, and adults of T. molitor after exposure to six concentrations of each essential oil and toxic compounds were evaluated. The chemical composition of the cinnamon oil was also determined and primary compounds were eugenol (10.19%), trans-3-caren-2-ol (9.92%), benzyl benzoate (9.68%), caryophyllene (9.05%), eugenyl acetate (7.47%), α-phellandrene (7.18%), and α-pinene (6.92%). In clove essential oil, the primary compounds were eugenol (26.64%), caryophyllene (23.73%), caryophyllene oxide (17.74%), 2-propenoic acid (11.84%), α-humulene (10.48%), γ-cadinene (4.85%), and humulene oxide (4.69%). Cinnamon and clove essential oils were toxic to T. molitor. In toxic chemical compounds, eugenol have stronger contact toxicity in larvae, pupae, and adult than caryophyllene oxide, followed by α-pinene, α-phellandrene, and α-humulene. In general, the two essential oils were toxic and repellent to adult T. molitor. Cinnamon and clove essential oils and their compounds caused higher mortality and repellency on T. molitor and, therefore, have the potential for integrated management programs of this insect.

Antioedematogenic activity, acetylcholinesterase inhibition and antimicrobial properties of Jacaranda oxyphylla.

Jacaranda oxyphylla Cham. (Bignoniaceae) is a shrub found in the Brazilian cerrado and used in folk medicine to treat microbial infections. The aim of this study was to carry out a phytochemical screening and evaluate antioedematogenic, antimicrobial and antiacetylcholinesterase properties of J. oxyphylla crude extracts. All extracts analysed showed presence of terpenoids, which are potentially active chemical substances. A high AChE inhibitory activity for hexane extract from leaves and for the extracts from twigs was found. Ethanol extract from leaves of J. oxyphylla showed activity against Gram-positive (Staphylococcus aureus and Bacillus cereus) and Gram-negative (Escherichia coli) bacteria. This extract was also effective in inhibiting the stages of inflammation evaluated. Biological investigation and phytochemical screening of J. oxyphylla extracts provided additional evidence of its traditional medicinal value.

Estudo farmacobotânico das folhas de Garcinia brasiliensis Mart. (Clusiaceae) / Pharmacobotanical studies of Garcinia brasiliensis Mart. (Clusiaceae) leaves

A espécie Garcinia brasiliensis Mart. (Clusiaceae), nativa da região Amazônica e cultivada em todo o território brasileiro, vem sendo bastante estudada devido seu potencial farmacológico, porém são escassos estudos que tratam da caracterização farmacobotânica desta espécie. Considerando as propriedades terapêuticas para tornar-se um medicamento fitoterápico, o presente trabalho teve como objetivos estudar a anatomia e histoquímica da folha e do pecíolo e elaborar dados macroscópicos e microscópicos que forneçam características marcantes para sua identificação além de dar subsídios para a análise farmacognóstica no controle de qualidade da droga vegetal. O material vegetal foi fixado e submetido às técnicas usuais de microscopia de luz e a testes histoquímicos. As folhas de G. brasiliensis são opostas, simples, descolores, forma elíptica com nervação peninérvia. As células epidérmicas, em vista frontal, apresentam contorno sinuoso e estômatos paracíticos somente na face abaxial. O mesofilo é dorsiventral, a nervura central apresenta contorno biconvexo e feixe vascular em forma de semi-arco fechado envolto por bainha esclerenquimática. Inclusões inorgânicas de cristais na forma de drusas e orgânicas representadas por compostos fenólicos e grãos de amidos estão dispersos ao longo de toda lâmina foliar e pecíolo. Observa-se com frequência a presença de canais secretores preenchidos por um conteúdo lipídico dispersos pelo parênquima fundamental e próximos aos feixes vasculares. Estes dados fornecem subsídios para o controle de qualidade da matéria-prima utilizada para a produção de fitoterápicos.

The Garcinia brasiliensis Mart. (Clusiaceae) species, native of the Amazon region and cultivated throughout the Brazilian territory, has been widely studied due to its pharmacological potential, but there are few studies dealing with the pharmacobotanic characterization of this species. Considering the therapeutic properties in order to become an herbal medicine, the present paper had the purpose of studying the anatomical and histochemical characterization of the leaf and petiole, as well as producing macroscopic and microscopic data that provide important characteristics for its identification, in addition to providing subsidies for the pharmacognostical analysis in order to offer elements for the quality assurance of the drug. The botanical material was prepared through the usual optical and histochemical microtechniques. The leaves of G. brasiliensis are simple, opposed, colorless, and they show an elliptical shape. As seen from the front, the epidermal cells have a sinuous contour, and paracytic stomata occur on the low surface. The leaves are hipostomatic and dorsiventral with heterogeneous mesophile. The mesophile is dorsiventral, the central midrib shows a biconvex contour and vascular system in a semi-closed arch shape surrounded by a sclerenchymatic sheath. Inorganic inclusions of crystals in the shape of druses, and organic inclusions represented by phenolic compounds and starch grains are found throughout the leaf blade and petiole. It is common to find secretory canals filled with a lipid content dispersed throughout the parenchyma and near the vascular bundles. These data support the quality assurance of the elements used to produce herbal medicines.

Pseudopolymorphism in hydroxybenzophenones: the dihydrate of 2,2',4,4'-tetrahydroxybenzophenone.

A dihydrate pseudopolymorph of bis(2,4-dihydroxyphenyl)methanone, C(13)H(10)O(5)·2H(2)O, (I), was obtained during polymorphism screening of hydroxybenzophenone derivatives. This structure, in which the molecule sits on a twofold axis, was compared with the known anhydrous form of (I) [Schlemper (1982). Acta Cryst. B38, 554-559]. The role of water in the crystal assembly was established on the basis of the known monohydrate pseudopolymorph of 3,4-dihydroxybenzophenone [Landre, Souza, Corrêa, Martins & Doriguetto (2010). Acta Cryst. C66, o463-o465].

Leishmanicidal activity of benzophenones and extracts from Garcinia brasiliensis Mart. fruits.

Infections by protozoans of the genus Leishmania are the major worldwide health problem, with high endemicity in developing countries. The drugs of choice for the treatment of leishmaniasis are the pentavalent antimonials, which exert renal and cardiac toxicity. Thus, there is a strong need for safer and more effective treatments against leishmaniasis. The present study was designated to evaluate, by a bioguided assay, the leishmanicidal activity of extracts (hexane, ethyl-acetate and ethanolic) and molecules both obtained by means of extraction from pericarps of Garcinia brasiliensis fruits. The hexane extract presented the best activity on the extracellular (promastigotes) and intracellular (amastigotes) forms of Leishmania (L.) amazonensis, when compared to the other extracts. Based on these findings, this extract was fractionated by silica gel column chromatography, affording nine fractions then resulting in three purified prenylated benzophenones - 7-epi-clusianone (1), garciniaphenone (2) and guttiferone-a (3). They showed significant activity on Leishmania (L.) amazonensis, and little toxicity for mammalian cells. Structure-activity relationships were evaluated showing that the IC(50) value displayed is dependent of prenyl groups and phenolic hydroxyls number, and inversely proportional to the hydrophobicity. Our results are promising, showing that these compounds are biologically active on Leishmania (L.) amazonensis.

Antimicrobial activity of benzophenones and extracts from the fruits of Garcinia brasiliensis.

The pericarp and seeds from fruits of Garcinia brasiliensis were subjected to extraction with hexane and ethanol. The pericarp hexane extract (PHE) and seed ethanol extract (SEE) were purified by silica gel column chromatography, which permitted isolation of the prenylated benzophenones 7-epiclusianone (1) and guttiferone-A (2), respectively. The antimicrobial activity of PHE, SEE, and compounds 1 and 2 were evaluated against Candida albicans, Staphylococcus aureus, Escherichia coli, and Bacillus cereus cultures. The minimum inhibitory concentration and minimum bactericidal concentration were established. The substances presented activity against S. aureus and B. cereus as follows: PHE, 4.0 microg/mL and 2.4 microg/mL; SEE, 10.0 microg/mL and 12.6 microg/mL; 7-epiclusianone, 1.2 microg/mL and 0.6 microg/mL; and guttiferone-A, 2.4 microg/mL and 2.4 microg/mL, respectively. The direct relationship between the lipophilic character of the structure and activity in Gram-positive bacteria was specifically observed. Therefore these extracts and prenylated benzophenones represent an interesting topic for further studies and open possibilities for an alternative control of diseases associated with Gram-positive bacteria.

Anti-inflammatory and cicatrizing activities of a carbohydrate fraction isolated from sugary kefir.

Kefir is an association of microrganisms generally grown in milk, with known probiotic activities identified from its soured suspensions. Aqueous media are also able to grow kefir, but little is known about the probiotic properties of its fermented products. This work aimed to evaluate some probiotic properties of a carbohydrate fraction isolated from sugary kefir (sugary kefir carbohydrate [SKC]). Anti-inflammatory activity of the isolated fraction of carbohydrate was tested both in vitro (cellular respirometry and macrophage culture) and in vivo (50% effective dose, rat paw edema, vascular permeability, and cicatrizing test). The results indicated no significant difference for oxygen uptake or macrophage culture between control and test groups. Rat paw edema, however, showed a significant inhibitory activity by 30 +/- 4% and 54 +/- 8% (P < .001) for carrageenan and dextran, respectively. In the cicatrizing test, animals treated with SKC cream also presented less trauma after treatments as compared to the negative control group (P < .05). The overall data suggested the SKC as a natural product that could be used as a constituent of an anti-inflammatory compound.

Antimicrobial activity of Rheedia brasiliensis and 7-epiclusianone against Streptococcus mutans.

This in vitro study evaluated the antimicrobial activity of extracts obtained from Rheedia brasiliensis fruit (bacupari) and its bioactive compound against Streptococcus mutans. Hexane, ethyl-acetate and ethanolic extracts obtained (concentrations ranging from 6.25 to 800 microg/ml) were tested against S. mutans UA159 through MIC/MBC assays. S. mutans 5-days-old biofilms were treated with the active extracts (100 x MIC) for 0, 1, 2, 3 and 4h (time-kill) and plated for colony counting (CFU/ml). Active extracts were submitted to exploratory chemical analyses so as to isolate and identify the bioactive compound using spectroscopic methods. The bioactive compound (concentrations ranging from 0.625 to 80 microg/ml) was then tested through MIC/MBC assays. Peel and seed hexane extracts showed antimicrobial activity against planktonic cells at low concentrations and were thus selected for the time kill test. These hexane extracts reduced S. mutans biofilm viability after 4h, certifying of the bioactive compound presence. The bioactive compound identified was the polyprenylated benzophenone 7-epiclusianone, which showed a good antimicrobial activity at low concentrations (MIC: 1.25-2.5 microg/ml; MBC: 10-20 microg/ml). The results indicated that 7-epiclusianone may be used as a new agent to control S. mutans biofilms; however, more studies are needed to further elucidate the mechanisms of action and the anticariogenic potential of such compound found in R. brasiliensis.

Vascular effects of 7-epiclusianone, a prenylated benzophenone from Rheedia gardneriana, on the rat aorta.

The vascular effects of 7-epiclusianone on the rat aorta were investigated. In the rat aortic rings with functional endothelia, 7-epiclusianone up to 10microM induced a concentration-dependent vasodilatation of the sustained contractions induced by phenylephrine (0.3microM). At concentrations higher than 10microM, 7-epiclusianone induced a concentration-dependent contraction in the aortic rings. The vasodilator effect of 7-epiclusianone was drastically decreased with L-NAME (100microM) as well as in endothelium-denuded aortic rings. Moreover, indomethacin (10microM) induced a significant shift to the left in the vasodilator but did not modify the vasoconstrictor effect of 7-epiclusianone. In arteries without pre-contraction, 7-epiclusianone (3-100microM) induced concentration-dependent contraction only in endothelium-intact and in the presence of L-NAME (100microM). This effect was inhibited by indomethacin (10microM) and ZM230487 (1microM), selective inhibitors of cyclooxygenase and of 5-lipoxygenase, respectively. We can conclude that at low concentrations 7-epiclusianone induces an endothelium-dependent vasodilator effect in rat aortic rings. At higher concentrations and in conditions where NO synthase was inhibited, 7-epiclusianone induces a vasocontractile effect. Nitric oxide seems to participate in the vasodilatation, while endothelial cyclooxygenase- and 5-lipoxygenase-derived products play a role in the vasoconstrictor effect.

Biological activities of 7-epiclusianone.

7-Epiclusianone, isolated from Rheedia gardneriana, was tested in several biological assays. It was active in vitro against trypomastigotes of Trypanosoma cruzi but inactive in vivo in experimentally infected mice. It was also active against Artemia salina, but inactive against the fungus Cladosporium sphaerospermum and the snail Biomphalaria glabrata.