In vitro activity of hypnophilin from Lentinus strigosus: a potential prototype for Chagas disease and leishmaniasis chemotherapy

Hypnophilin and panepoxydone, terpenoids isolated from Lentinus strigosus, have significant inhibitory activity onTrypanosoma cruzi trypanothione reductase (TR). Although they have similar TR inhibitory activity at 10 μg/mL (40.3 μM and 47.6 μM for hypnophilin and panepoxydone, respectively; ~100 percent), hypnophilin has a slightly greater inhibitory activity (~71 percent) on T. cruzi amastigote (AMA) growth in vitro as well as on in vitro phytohemagglutinin (PHA)-induced peripheral blood mononuclear (PBMC) proliferation (~70 percent) compared to panepoxydone (69 percent AMA inhibition and 91 percent PBMC inhibition). Hypnophilin and panepoxydone at 1.25 μg/mL had 67 percent inhibitory activity onLeishmania (Leishmania) amazonensis amastigote-like (AMA-like) growth in vitro. The panepoxydone activity was accompanied by a significant inhibitory effect on PHA-induced PBMC proliferation, suggesting a cytotoxic action. Moreover, incubation of human PBMC with panepoxydone reduced the percentage of CD16+ and CD14+ cells and down-regulated CD19+, CD4+ and CD8+ cells, while hypnophilin did not alter any of the phenotypes analyzed. These data indicate that hypnophilin may be considered to be a prototype for the design of drugs for the chemotherapy of diseases caused by Trypanosomatidae.

Antifungal activities of compounds isolated from Piper abutiloides Kunth.

Piperaceae is a family of tropical plants known to have antifungal, antibacterial, tumour-inhibitory, antiviral, antioxidant, molluscicidal and leishmanicidal activities. In this work, extracts and fractions from aerial parts of Piper abutiloides (Piperaceae), a traditional medicinal plant, were evaluated against the fungal species Candida albicans, C. parapsilosis, C. krusei, C. glabrata, C. tropicalis, Cryptococcus neoformans and Sporothrix schenckii. The results have shown that the antifungal activity of this plant can be concentrated in the hexanic fraction after partitioning its hydroalcoholic extract between hexane and 90% aqueous methanol. The chromatographic fractionation of the bioactive part was monitored with a bioautographic assay using C. glabrata, and allowed the isolation of three antifungal compounds: pseudodillapiol, eupomatenoid-6 and conocarpan. These compounds presented different potencies against the fungi tested, with the strongest effect being observed for eupomatenoid-6 against C. glabrata, which presented a minimal inhibitory concentration value of 0.3 microg spot(-1). Conocarpan showed antifungal activity without apparent cytotoxic effect on normal human lymphocytes, as assessed by the proliferation assay with human peripheral blood mononuclear cells stimulated with phytohaemaglutinin. This work reveals for the first time the occurrence of these compounds in P. abutiloides and justifies further studies to clarify their mechanisms of action.

Efeito do miriadenolídeo isolado de Alomia myriadenia (Asteraceae) sobre o tumor de Erlich ascítico no camundongo / Effect of myriadenolide isolated from Alomia myriadenia (Asteraceae) on Ehrlich tumor in its ascitic form

Estudou-se atividade antineoplásica de um produto natural isolado de Alomia myriadenia (miriadenolídeo) no modelo do tumor de Ehrlich em camundongos. Dezoito fêmeas de camundongo Swiss foram inoculadas com 2x10(7) células viáveis de tumor de Ehrlich via intraperitoneal (0,3ml) e posteriormente distribuídas aleatoriamente em três grupos que receberam: grupo I (controle) - 0,3ml de solução de Hanks; grupo II - 31µg/kg de miriadenolídeo; e grupo III - 139µg/kg de miriadenolídeo. No oitavo dia de experimento, foram realizados exames hematológicos e perfil protéico sérico eletroforético. Coletou-se todo o líquido ascítico para avaliação do volume, aparência, pH, contagem de células viáveis e inviáveis, realização de esfregaços para contagem de células claras e escuras, leucócitos e avaliação das regiões organizadoras de nucléolos argentafins (AgNORs). Foram realizados exames macro e microscópicos do baço, fígado e rins e aspirado o conteúdo da medula óssea dos fêmures direito e esquerdo de cada animal para avaliação da relação mielóide:eritróide. Não houve diferença significativa no volume, pH, contagem de células viáveis e inviáveis entre os três grupos estudados, observando-se valores de 17,6 x 10(4) células tumorais viáveis no grupo III, 27,7 x 10(4) no grupo II e 21,1 x 10(4) no grupo I. As AgNORs apresentaram-se pequenas, com distribuição difusa e incontáveis no grupo I, e em menor quantidade no grupo III. Os animais do grupo III apresentaram a menor concentração protéica total sérica (4,7g/dl) (P<0,05) quando comparados com os do grupo II (5,3g/dl) e do grupo I (5,1g/dl). Os valores de albumina foram semelhantes nos três grupos (2,6g/dl), e as globulinas totais foram maiores (P<0,05) no grupo II (2,71g/dl) quando comparadas com os valores médios do grupo III (2,11g/dl) e semelhantes ao grupo I (2,43g/dl). Não houve diferença entre alfa e beta globulinas entre os três grupos estudados, porém as gamaglobulinas foram maiores...

Antitumoral activity of a natural product of Alomia myriadenia (myriadenolide) in Ehrlich tumor in mice was studied. Eighteen Swiss female mice were intra-peritoneal inoculated 2x10(7) viable cells of Ehrlich Tumor (0.3ml) and randomly distributed in three groups receiving via intra-peritoneal on the 3rd and 5th day post-inoculation the following treatments: group I (control) - 0.3ml Hanks solution; group II: 31µg/kg myriadenolide; and group III: 139µg/kg myriadenolide. On the eighth day of the experiment blood profile and protein serum electrophoresis were performed. All ascitic liquid was collected to evaluate the volume and pH; to observe the aspect; to count viable and no viable cells, dark and clear cells, leukocytes and nucleolar organizer regions (NORs). Macro and microscopic exams were performed and bone marrow was aspirated from right and left femurs of each animal to evaluate myeloid:erythroid ratio. It was not observed difference in volume, pH, counts viable and no viable cells in the groups, although group III showed smaller number of viable tumoral cells (17.6 x 10(4)) when compared to the group II (27.7 x 10(4)) and group I (21.1 x 10(4)). The investigation of NORs to evaluate the proliferative capacity of tumoral cells after myriadenolide treatment showed that cells were smaller, uncountable and with diffuse distribution in group I. They were in lower quantity in group III. These results suggest that myriadenolide in dose 139µg/kg (group III) delay the tumoral growing and, probably, cell proliferation. The animals of group III showed lower value of total protein (4.7g/dl) (P<0.05) when compared to animals from group II (5.3g/dl) and group I (5.1g/dl). The values of albumin were similar in all groups (2.6g/dl) and total globulin was higher (P<0.05) in group II (2.71g/dl) when compared to mean values of group III (2.11g/dl) and similar to group I (2.43g/dl). The decrease of total protein in group III occurred...

Clinical and laboratory evaluation of compliance in acute lymphoblastic leukaemia.

AIM: To evaluate compliance in children with acute lymphoblastic leukaemia (ALL). METHODS: Compliance was assessed through specific interviews, annotations from medical charts, and erythrocytic determination of 6-mercaptopurine metabolites. RESULTS: A total of 39 patients who had concluded maintenance phase of chemotherapy were included in the study. Mothers were responsible for delivering 6-MP in 87% of cases. Thirty five interviewees said that medical prescription was well understood and that the main reason for non-compliance was forgetfulness. Non-compliance was detected through interviews (33.3% of the cases), reports from medical charts (30.7%), and drug determination (16.6%); 53.8% of children were found to be non-compliant. Non-compliance was significantly associated with chronic undernourishment. Although not statistically significant, there was a trend for the group of non-compliant children to be associated with low per capita family income. No significant associations of non-compliance with age at diagnosis, gender, parents' schooling level, number of family members, power consumption, and medians of absolute leucocyte or neutrophil blood counts were detected. A short follow up period precluded valid analysis on outcome. In the non-compliant group (n = 21), seven children relapsed, contrasting with three relapses in the compliant group (n = 18). CONCLUSIONS: Results suggest that non-compliance is one of the mechanisms which underlies the adverse influence of socioeconomic factors on the outcome of children with ALL. Additional studies are necessary to confirm this hypothesis. Comprehensive approaches to the problem of non-compliance are urgently needed.

An improved HPLC method for the quantitation of 6-mercaptopurine and its metabolites in red blood cells

A procedure is described for the rapid determination of the intra-erythrocyte concentration of 6-mercaptopurine (6-MP) and its metabolites, 6-thioguanine nucleotides (6-TGN) and 6-methylmercaptopurine (6-MMP). Erythrocytes (8 x 10(8) cells) in 350 æl Hanks solution containing 7.5 mg dithiothreitol were treated with 50 æl 70 percent perchloric acid. The precipitate was removed by centrifugation (13,000 g) and the supernatant hydrolyzed at 100§C for 45 min. After cooling, 100 æl was analyzed directly by HPLC using a Radialpack Resolve C18 column eluted with methanol-water (7.5:92.5, v/v) containing 100 mM triethylamine. 6-TG, 6-MP and the hydrolysis product of 6-MMP, 4-amino-5-(methylthio)carbonyl imidazole, were monitored at 342, 322 and 303 nm using a Shimadzu SPD-M10A diode array UV detector. The analytes eluted at 5.3, 6.0 and 10.2 min, respectively. The calibration curves were linear (rý > 0.998), and the analytical recoveries were 73.2 percent for 6-TG, 119.1 percent for 6-MP and 97.4 percent for 6-MMP. The intra- and inter-assay variations were highest for 6-MP (9.6 and 14.3 percent, respectively). The lowest detectable concentrations were 3, 3 and 25 pmol/8 x 10(8) erythrocytes for 6-TG, 6-MP and 6-MMP, respectively. The quantification limits (coefficients of variation <15 percent) were 8, 10 and 70 pmol/8 x 10(8) erythrocytes for 6-TG, 6-MP and 6-MMP, respectively. The method was applied to the analysis of 183 samples from 36 children under chemotherapy for acute lymphoblastic leukemia. The concentrations of the metabolites in the red cells of the patients ranged from 0 to 1934 pmol/8 x 10(8) erythrocytes for 6-TGN, and from 0 to 105.8 and 0 to 45.9 nmol/8 x 10(8) erythrocytes for 6-MP and 6-MMP, respectively. The procedure gave results that were in agreement with those obtained with other methods designed to detect cases of non-compliance with treatment, including patient interviews and medical evaluation, among others, demonstrating its applicability to monitoring the treatment of leukemic children.

An improved HPLC method for the quantitation of 6-mercaptopurine and its metabolites in red blood cells.

A procedure is described for the rapid determination of the intra-erythrocyte concentration of 6-mercaptopurine (6-MP) and its metabolites, 6-thioguanine nucleotides (6-TGN) and 6-methylmercaptopurine (6-MMP). Erythrocytes (8 x 10(8) cells) in 350 microl Hanks solution containing 7.5 mg dithiothreitol were treated with 50 microl 70% perchloric acid. The precipitate was removed by centrifugation (13,000 g) and the supernatant hydrolyzed at 100 degrees C for 45 min. After cooling, 100 microl was analyzed directly by HPLC using a Radialpack Resolve C18 column eluted with methanol-water (7.5:92.5, v/v) containing 100 mM triethylamine. 6-TG, 6-MP and the hydrolysis product of 6-MMP, 4-amino-5-(methylthio)carbonyl imidazole, were monitored at 342, 322 and 303 nm using a Shimadzu SPD-M10A diode array UV detector. The analytes eluted at 5.3, 6.0 and 10.2 min, respectively. The calibration curves were linear (r(2) > 0.998), and the analytical recoveries were 73.2% for 6-TG, 119.1% for 6-MP and 97.4% for 6-MMP. The intra- and inter-assay variations were highest for 6-MP (9.6 and 14.3%, respectively). The lowest detectable concentrations were 3, 3 and 25 pmol/8 x 10(8) erythrocytes for 6-TG, 6-MP and 6-MMP, respectively. The quantification limits (coefficients of variation <15%) were 8, 10 and 70 pmol/8 x 10(8) erythrocytes for 6-TG, 6-MP and 6-MMP, respectively. The method was applied to the analysis of 183 samples from 36 children under chemotherapy for acute lymphoblastic leukemia. The concentrations of the metabolites in the red cells of the patients ranged from 0 to 1934 pmol/8 x 10(8) erythrocytes for 6-TGN, and from 0 to 105.8 and 0 to 45.9 nmol/8 x 10(8) erythrocytes for 6-MP and 6-MMP, respectively. The procedure gave results that were in agreement with those obtained with other methods designed to detect cases of non-compliance with treatment, including patient interviews and medical evaluation, among others, demonstrating its applicability to monitoring the treatment of leukemic children.

IL-4 and IL-13 regulate the induction of indoleamine 2,3-dioxygenase activity and the control of Toxoplasma gondii replication in human fibroblasts activated with IFN-gamma.

The ability of up-regulatory [recombinant (r) IFN-gamma, rIFN-beta and rTNF-alpha] and down-regulatory (rIL-4, rIL-10 and rIL-13) cytokines to control the expression of indoleamine 2,3-dioxygenase (INDO) and anti-Toxoplasma activity in the human fibrosarcoma cell line 2C4 was evaluated. Activation of fibroblasts with rIFN-gamma, rIFN-beta and rTNF-alpha resulted in augmentation of INDO expression and activity leading to 40.0, 25.0 and 27.0 % inhibition of tachyzoite growth, respectively. An additive effect was observed when host cells were incubated with rIFN-gamma plus rTNF-alpha. With regard to the down-regulatory cytokines we observed that IL-4 as well as IL-13, but not IL-10, induced significant inhibition of IFN-gamma-induced control of parasite replication, INDO mRNA expression and tryptophan catabolism. Similarly, IL-4 but not IL-10 inhibited the cell surface expression of HLA-DR and CD2 induced by IFN-gamma. Consistent with these findings we were able to detect by reverse transcription-PCR the expression of mRNA for different chains of IL-4 and IL-13 receptors (IL-4Ralpha, IL-13Ralpha1 and IL-13Ralpha2) but not for IL-10 receptor in the 2C4 and other human lung fibroblast cell lines (LL24 and MRC5). Together our results indicate that IL-4 and IL-13, but not IL-10, are implicated in the negative regulation of IFN-gamma-induced anti-Toxoplasma activity in human cells from fibroblast lineage.

A cytotoxic diterpene from Alomia myriadenia.

An extract of the aerial parts from Alomia myriadenia Schultz-Bip. ex Baker (Asteraceae) showed significant cytotoxicity against a panel of human cancer cell lines in a screening of extracts from Brazilian Atlantic Forest plant species. Employing a bioassay-linked HPLC-electrospray/MS method, followed by semi-preparative HPLC, the active component was isolated and characterized as a mixture of epimers of the labdane diterpene 12S,16-dihydroxy-ent-labda-7,13-dien-15,16-olide.