Gastric toxicity of Alendronate and Methotrexate in Walker 256 carcinosarcoma jaw model / Toxicidade gástrica de Alendronato e Metotrexato em modelo de carcinossarcoma de Walker 256 em mandíbula

Introduction: Experimental animal models represent a key tool used to elucidate the mechanisms of action and toxicity of anticancer drugs. Objective: The purpose was to establish a correlation of neoplastic growth with the combinatorial therapeutic application of sodium alendronate (ALD) and methotrexate (MTX), and to evaluate the gastrointestinal toxicity of these drugs, in the rat Walker 256 carcinosarcoma inoculation model. Methods: Female rats were selected and randomly distributed into 5 groups (n=10): negative control (NC), positive control (PC), MTX-treated group, ALD-treated group, and MTX-ALD-treated group (MTX/ALD). Tumor cells were inoculated as a suspension of 1x106cells/mL into the alveolar cavities produced by exodontia procedures. The following parameters were evaluated: body weight, tumor volume and percentage of tumor inhibition, and gastrointestinal toxicity. Results: The body weight variation was statistically significant between NC animals and PC animals, and between NC animals and ALD-treated group (p<0.01). Tumor volume variation was statistically significant between PC animals, MTX-treated group and MTX/ALD-co-treated group (p<0.05). Analysis of gastric toxicity of MTX-treated group reveled slight reduction of chief (Ch) and parietal (Pr) cellular populations; ALD-treated group exhibited gastric mucosa without histological alterations of Ch cells but intense reduction of Pr cellular population; and MTX/ALD-co-treated group presented reduction of Ch and Pr cellular populations. Conclusions: ALD does not elicit significant antitumor effects on Walker 256 carcinosarcoma cells and decreases antitumor effects of MTX due to toxicity on the gastric epithelium, which is intensified with MTX association.

Introdução: Modelos experimentais em animais representam um instrumento fundamental para elucidar os mecanismos de ação e toxicidade de drogas anticâncer. Objetivo: estabelecer uma correlação do crescimento neoplásico com a aplicação terapêutica combinatória de alendronato de sódio (ALD) e metotrexato (MTX), e avaliar a toxicidade gastrointestinal dessas drogas, no modelo de inoculação de carcinossarcoma de Walker 256 em ratos. Métodos: Ratas fêmeas foram selecionadas e distribuídas aleatoriamente em 5 grupos (n = 10): controle negativo (NC), controle positivo (PC), grupo tratado com MTX, grupo tratado com ALD e grupo tratado com MTX-ALD (MTX/ALD). As células tumorais foram inoculadas como uma suspensão de 1x106 células/mL nas cavidades alveolares produzidas por procedimentos de exodontia. Os seguintes parâmetros foram avaliados: peso corporal, volume tumoral e porcentagem de inibição tumoral e toxicidade gastrointestinal. Resultados: A variação do peso corporal foi estatisticamente significante entre animais NC e animais PC, e entre animais NC e grupo tratado com ALD (p <0,01). A variação do volume tumoral foi estatisticamente significativa entre animais PC, grupo tratado com MTX e grupo tratado com MTX / ALD (p <0,05). A análise da toxicidade gástrica do grupo tratado com MTX revelou uma ligeira redução das populações celulares principais (Ch) e parietais (Pr); o grupo tratado com ALD exibiu mucosa gástrica sem alterações histológicas de células Ch mas intensa redução da população celular Pr; e o grupo tratado com MTX / ALD apresentou redução das populações celulares Ch e Pr. Conclusões: O ALD não provoca efeitos antitumorais significativos nas células do carcinossarcoma Walker 256 e diminui os efeitos antitumorais do MTX devido à toxicidade no epitélio gástrico, que é intensificada com a associação MTX.

Cytotoxicity against tumor cell lines and anti-inflammatory properties of chitinases from Calotropis procera latex.

The role of chitinases from the latex of medicinal shrub Calotropis procera on viability of tumor cell lines and inflammation was investigated. Soluble latex proteins were fractionated in a CM Sepharose Fast-Flow Column and the major peak (LPp1) subjected to ion exchange chromatography using a Mono-Q column coupled to an FPLC system. In a first series of experiments, immortalized macrophages were cultured with LPp1 for 24 h. Then, cytotoxicity of chitinase isoforms (LPp1-P1 to P6) was evaluated against HCT-116 (colon carcinoma), OVCAR-8 (ovarian carcinoma), and SF-295 (glioblastoma) tumor cell lines in 96-well plates. Cytotoxic chitinases had its anti-inflammatory potential assessed through the mouse peritonitis model. We have shown that LPp1 was not toxic to macrophages at dosages lower than 125 µg/mL but induced high messenger RNA expression of IL-6, IL1-ß, TNF-α, and iNOs. On the other hand, chitinase isoform LPp1-P4 retained all LPp1 cytotoxic activities against the tumor cell lines with IC50 ranging from 1.2 to 2.9 µg/mL. The intravenous administration of LPp1-P4 to mouse impaired neutrophil infiltration into the peritoneal cavity induced by carrageenan. Although the contents of pro-inflammatory cytokines IL-6, TNF-α, and IL1-ß were high in the bloodstreams, such effect was reverted by administration of iNOs inhibitors NG-nitro-L-arginine methyl ester and aminoguanidine. We conclude that chitinase isoform LPp1-P4 was highly cytotoxic to tumor cell lines and capable to reduce inflammation by an iNOs-derived NO mechanism.

Endocrine disruption in Sphoeroides testudineus tissues and sediments highlights contamination in a northeastern Brazilian estuary.

In recent decades, considerable attention has been devoted to endocrine disruptor chemicals (EDC) and studies on fish feminization have increased throughout the years as a key signal for aquatic environmental contamination. The input of domestic sewage into water reservoirs is common in South American countries, especially in cities that experienced rapid population growths and unplanned urbanization. This study aimed at characterizing morphofunctional parameters of the tropical fish Sphoeroides testudineus and investigating the potential occurrence and effects of endocrine disruptors in the Pacoti River (Ceará, Brazil), often considered a reference site. After collection from the field, fish were measure/weighted and desiccated for gender identification (males, females, and undifferentiated), gonadal histology, and vitellogenin expression. From the biometric analysis, undifferentiated fish showed lower weight and length than female and male fish, although no differences in the condition index were observed. The gonadal weight of undifferentiated fish was significantly lower than those of females and males. Although this pattern was observed, gonadosomatic index (GSI) showed a different pattern, with differences being observed just between males and the other two groups (females and undifferentiated). Vitellogenin (VTG) expression was detected in many mature male and undifferentiated fish, indicating endocrine disruption. In addition, several EDCs (estrone, 17α-estradiol, 17ß-estradiol, 17α-ethinylestradiol, diethylstilbestrol, and estriol) were identified and quantified in sediments from the sampling site. These results were unexpected and indicative that the Pacoti River is impaired by estrogenic contamination.

Biomimetic oxidation of piperine and piplartine catalyzed by iron(III) and manganese(III) porphyrins.

Synthetic metalloporphyrins, in the presence of monooxygen donors, are known to mimetize various reactions of cytochrome P450 enzymes systems in the oxidation of drugs and natural products. The oxidation of piperine and piplartine by iodosylbenzene using iron(III) and manganese(III) porphyrins yielded mono- and dihydroxylated products, respectively. Piplartine showed to be a more reactive substrate towards the catalysts tested. The structures of the oxidation products were proposed based on electrospray ionization tandem mass spectrometry.

Cytotoxic guanidine alkaloids from Pterogyne nitens.

As part of a bioprospecting program aimed at the discovery of potential anticancer drugs, two new guanidine-type alkaloids, nitensidines D and E (1, 2), and the known pterogynine (3), pterogynidine (4), and galegine (5), were isolated from the leaves of Pterogyne nitens. The structures of 1 and 2 were established on the basis of spectroscopic data interpretation. These compounds were tested against a small panel of human cancer cell lines. Compound 2 exhibited cytotoxicity for HL-60 (human myeloblastic leukemia) and SF-245 (human glioblastoma) cells.

Evaluation of mutagenic effects of formocresol: detection of DNA-protein cross-links and micronucleus in mouse bone marrow.

OBJECTIVE: The genotoxic potential of formocresol was assessed by comet assay on human peripheral blood lymphocytes and in vivo micronucleus in mice. STUDY DESIGN: Peripheral blood lymphocytes, obtained from healthy donors, were exposed directly with different dilutions of formocresol for 45 minutes at 37 degrees C. To verify the possibility of formocresol to induce DNA-protein cross-links, treated lymphocytes were incubated with proteinase K. Micronucleus test was performed on male Swiss mice treated with several dilutions of formocresol by single intraperitoneal injection. After treatment, bone marrow was sampled 24 and 48 hours after formocresol administration. RESULTS: Formocresol did not produce detectable DNA damage as evaluated by comet assay. However, after proteinase K exposure, a dose-dependent increase of DNA migration was observed. Formocresol induced a significant increase in micronucleus frequencies at the highest dilution only at 24 hours after administration. CONCLUSION: Formocresol induced DNA-protein cross-links and an increased frequency of micronucleus.