Evaluation of the in vitro trypanocidal activity of triterpenes uvaol, betulinic acid and its semi-synthetic derivatives against the Y strain of Trypanosoma cruzi / Avaliação da atividade tripanocida in vitro dos triterpenos uvaol, ácido betulínico e seus derivados semissintéticos contra a cepa Y de Trypanosoma cruzi

Chagas disease is a neglected tropical disease that affects millions of people worldwide. Trypanosoma cruzi (T. cruzi) is the causative agent of Chagas disease and its transmission occurs through blood meal by triatomine bugs, being oral transmission the most common form. More than 100 years after the disease´s discovery, benzonidazole is the only efficient drug against T. cruzi; however, this drug has numerous serious side effects and is only efficient in the acute phase of the disease. Natural products, such as triterpenes, have been an important source of new substances to combat human parasitology. In this study, two triterpenes, uvaol and betulinic acid, were tested against the parasite T. cruzi. The best results of in vitro tests were observed for uvaol with an IC50 value of 70.3 µM against the trypomastigost forms and an IC50 value of 90.6 µM against the amastigost forms. Three semi-synthetic derivatives of betulinic acid were obtained; the acetylated derivative showed excellent results against trypomastigotes forms (IC50 = 15.67 µM), but was not active against the amastigotes forms. The cytotoxic MTT test was also performed on LLCMK2 cells (Macaca mullata kidney epithelial cells) and betulinic acid showed the highest selectivity index (SI) with a value of 1.3

In Vitro Schistosomicidal Activity of Some Brazilian Cerrado Species and Their Isolated Compounds

, Struthanthus syringifolius (Mart.) (Loranthaceae), and Schefflera vinosa (Cham. & Schltdl.) Frodin (Araliaceae) are plant species from the Brazilian Cerrado whose schistosomicidal potential has not yet been described. The crude extracts, fractions, the triterpenes betulin, oleanolic acid, ursolic acid and the flavonoids quercetin 3- Schistosoma mansoni adult worms and the bioactive n-hexane fractions of the mentioned species were also analyzed by GC-MS. Betulin was able to cause worm death percentage values of 25% after 120 h (at 100 μM), and 25% and 50% after 24 and 120 h (at 200 μM), respectively; besides the flavonoid quercetin 3-O-β-d-rhamnoside promoted 25% of death of the parasites at 100 μM. Farther the flavonoids quercetin 3-O-β-d-glucoside and quercetin 3-O-β-d-rhamnoside at 100 μM exhibited significantly reduction in motor activity, 75% and 87.5%, respectively. Biological results indicated that crude extracts of R. montana, S. vinosa, and M. langsdorffii and some n-hexane and EtOAc fractions of this species were able to induce worm death to some extent. The results suggest that lupane-type triterpenes and flavonoid monoglycosides should be considered for further antiparasites studies

Essential Oils of Protium of the Adolpho Ducke Forest Reserve: Protium crassipetalum, P. heptaphyllum subs. ulei, P. pilosissimum and P. polybotryum

The essential oils from samples collected in the Adolpho Ducke Forest Reserve in the state of Amazonas were obtained by hydrodistillation and analyzed by GC-MS. The chemical composition of essential oils was characterized by high percentage of sesquiterpenoids. The oils of Protium crassipetalum leaves and branches showed predominance of α-copaene (19.6 and 15.2 %) and trans-caryophyllene (16.4 and 10.1 %), respectively, besides spathulenol (13.9 %), detected in the oil from the leaves. The main constituents in leaves of P. heptaphyllum subs. ulei were α-copaene (11.8 %), trans-caryophyllene (16.9 %) and germacrene B (12.8%). The oils of P. pilosissimum were marked by presence of β-sesquiphellandrene (24.3 %) in leaves and selin-11-en-4-α-ol of branches. Khusimone (35.9 %) was found to be the major constituent in the oil from P. polybotryum. The present study is intended as a contribution to the knowledge of the composition of the essential oils of the aerial parts of this biological reserve. © 2013 Har Krishan Bhalla & Sons

Síntese, atividade antimicrobiana e estudo in silico de 1,2,4-oxadiazóis derivados do levulinato de etila

This study analyzes the antileishmanial activity of the crude ethanol extract, fractions, and isolated compounds of A. othonianum nuts. Antileishmanial activity was evaluated against Leishmania amazonensis promastigotes in vitro. The phytochemical study was performed by high-performance liquid chromatography-high-resolution mass spectrometry-diode array detector (HPLC-HRMS-DAD) and by preparative HPLC. HPLC-HRMS-DAD analysis of the bioactive extract confirmed the presence of ten alkyl phenol derivatives that had previously been isolated from A. occidentale. Bioassay-guided isolation afforded cardanol triene, cardanol diene, cardanol monoene, cardol triene, anacardic acid triene, anacardic acid diene, and anacardic acid monoene. Cardol triene gave an IC50 of 80.66 µM. The obtained data suggest that the evaluated extract, fractions, and cardol triene had moderate activity against L. amazonensis promastigotes. This is the first description of alkyl phenols in A. othonianum.Este estudo visou avaliar a atividade antileishmanial do extrato bruto etanólico, frações e substâncias isoladas obtidos das castanhas de A. othonianum. A atividade antileishmania foi avaliada por ensaio in vitro nas formas promastigotas de Leishmania amazonensis. O estudo fitoquímico foi realizado por cromatografia líquida de alta eficiência - espectrometria de massa de alta resolução - detector de arranjo de diodos (CLAE-EMAR-DAD) e por CLAE-preparativa. A análise por CLAE-EMAR-DAD do extrato bioativo confirmou a presença de dez derivados de alquil-fenóis previamente isolados de A. occidentale.  A investigação bioguiada resultou no isolamento do cardanol trieno, cardanol dieno, cardanol monoeno, cardol trieno, ácido anacárdico trieno, ácido anacárico dieno e ácido anacárico monoeno. O cardol trieno apresentou uma CI50 de 80,66 µM. Os dados obtidos sugeriram que o extrato, frações e o cardol trieno possuem atividade moderada no ensaio nas formas promastigotas de L. amazonensis. Este é o primeiro relato de alquil-fenóis em A. othonianum

Curcumin Generates Oxidative Stress and Induces Apoptosis in Adult Schistosoma mansoni Worms.

Inducing apoptosis is an interesting therapeutic approach to develop drugs that act against helminthic parasites. Researchers have investigated how curcumin (CUR), a biologically active compound extracted from rhizomes of Curcuma longa, affects Schistosoma mansoni and several cancer cell lines. This study evaluates how CUR influences the induction of apoptosis and oxidative stress in couples of adult S. mansoni worms. CUR decreased the viability of adult worms and killed them. The tegument of the parasite suffered morphological changes, the mitochondria underwent alterations, and chromatin condensed. Different apoptotic parameters were determined in an attempt to understand how CUR affected adult S. mansoni worms. CUR induced DNA damage and fragmentation and increased the expression of SmCASP3/7 transcripts and the activity of Caspase 3 in female and male worms. However, CUR did not intensify the activity of Caspase 8 in female or male worms. Evaluation of the superoxide anion and different antioxidant enzymes helped to explore the mechanism of parasite death further. The level of superoxide anion and the activity of Superoxide Dismutase (SOD) increased, whereas the activity of Glutathione-S-Transferase (GST), Glutathione reductase (GR), and Glutathione peroxidase (GPX) decreased, which culminated in the oxidation of proteins in adult female and male worms incubated with CUR. In conclusion, CUR generated oxidative stress followed by apoptotic-like-events in both adult female and male S. mansoni worms, ultimately killing them

Chemical study of Adenocalymma axillarum crude leaf extract and isolated compounds

Adenocalymma axillarum (K.Schum.) L.G. Lohmann is a liana belonging to the family Bignoniaceae. In traditional medicine, the genus Adenocalymma is used to treat fever, skin ailments, and body, joint, and facial muscle pains, and it is also applied as cosmetic. Biological assays conducted with the A. axillarum crude leaf ethanol extract have indicated leishmanicidal activity and absence of cytotoxicity. This study aimed to analyze the A. axillarum leaf ethanol crude extract by high-performance liquid chromatography-high-resolution mass spectrometry- diode array detector (HPLC-HRMS-DAD) and to evaluate the leishmanicidal and cytotoxic activities of this crude extract, its fractions, and isolated compounds. HPLC-HRMS-DAD analysis of this extract revealed that it consisted mainly of flavonoids, with nine major compounds. Extract purification yielded 4-hydroxy-N-methylproline, 6-β-hydroxyipolamiide, quercetin-3-O-robinobioside, hyperin, isorhamnetin-3-O-robinobioside, and 3’-O-methylhyperin, which were identified by Nuclear Magnetic Resonance. The isolated compounds were inactive against Leishmania amazonensis promastigotes and human lung fibroblast cells

Investigation on the 19S ATPase proteasome subunits (Rpt1 6) conservation and their differential gene expression in Schistosoma mansoni.

The ubiquitin-proteasome system is responsible for degradation of the majority of intracellular proteins in eukaryotic cells. The 26S proteasome proteolytic complex is composed of a 20S core particle responsible for protein degradation and the 19S lid which plays a role in the recognition of polyubiquitinated substrates. The 19S regulatory particle (Rps) is composed of ATPase (Rpt) and non-ATPase (Rpn) subunits. In this study, we analyzed the expression profile of 19S Rpt subunits in the larvae and adult stage of the Schistosoma mansoni life cycle. Conventional reverse transcriptase polymerase chain reaction (RT-PCR) revealed that the majority of the 19S Rpt subunits amplified at the expected molecular masses for various investigated stages. In addition, SmRpt1, SmRpt2, and SmRpt6 transcript levels were increased in 3 h-cultured schistosomula and reasonably maintained until 5 h in culture, as revealed by qRT-PCR. Phylogenetic analysis of 19S Rpt subunits showed high structural conservation in comparison to other Rpt orthologues. The mRNA expression profile of 19S Rpt subunits did not correlate with 26S proteasome proteolytic activity as judged by a 14C-casein-degrading assay, in the early cultured schistosomula. Taken together, these results revealed a differential expression profile for 19S Rpt subunits whose transcript levels could not be directly associated to 26S proteasome activity

<i>In vitro</i> effect of CUR on the viability of adult <i>S</i>. <i>mansoni</i> worms as measured by MTT assay.

<p>Couples of adult worms were incubated with different concentrations of CUR for 6, 12, or 24 h. Adult (A) female and (B) male <i>S</i>. <i>mansoni</i> worms were separated, and the viability was measured by the MTT assay at 550 nm. In the negative control groups, couples of adult worms were incubated with RMPI 1640 medium or with RPMI 1640 medium with 0.1% DMSO. In the positive control groups, couples of adult worms were incubated with PZQ (1.56 μM) or heat-killed at 56°C. Values are expressed as the mean ± S.E.M of three independent experiments. An asterisk indicates statistically significant differences as compared to the negative control group (RPMI 1640 medium with 0.1% DMSO) (***<i>p <</i> 0.001).</p

CUR induces formation of the superoxide anion in adult <i>S</i>. <i>mansoni</i> worms.

<p>Couples of adult worms were incubated with CUR at 12.5 to 100 μM for 6, 12, or 24 h. After incubation, (A) female and (B) male <i>S</i>. <i>mansoni</i> worms were separated, and the level of superoxide anion was measured by the NBT assay at 620 nm. Couples of adult worms incubated with RPMI 1640 with 0.1% DMSO were used as negative control, and couples of adult worms incubated with RPMI 1640 medium with 100 μM hydrogen peroxide were used as positive control. The results represent the mean ± SEM of three independent experiments. An asterisk indicates statistically significant differences as compared to the negative control group (RPMI 1640 medium with 0.1% DMSO) (**<i>p</i> < 0.01, ***<i>p</i>< 0.001).</p