A styrylpyrone dimer isolated from Aniba heringeri causes apoptosis in MDA-MB-231 triple-negative breast cancer cells.

The styrylpyrone dehydrogoniothalamin (1) and two of its dimers (2 and 3) were isolated from the leaves of Aniba heringeri (Lauraceae). Compound 3 is new, while 1 and 2 are being reported for the first time in this species. Structures were determined by 1D- and 2D-NMR spectroscopy, mass spectrometry, and optical rotation data. Cytotoxic effects and selectivity indices were evaluated in five neoplastic cell lines-PC-3 (prostate), 786-0 (renal), HT-29 (colon), MCF-7, and MDA-MB-231 (breast)-and a non-neoplastic cell line, (NIH/3T3, murine fibroblast). Compound 1 inhibited cell growth by 50% (GI50) at concentrations in the 90.4-175.7 µM range, while 2 proved active against MCF-7 and MDA-MB-231 breast cells (GI50 = 12.24, and 34.22 µM, respectively). Compound 3 showed strong cytotoxicity (GI50 = 4.4 µM) against MDA-MB-231 (an established basal triple-negative breast carcinoma (TNBC) cell line), with a high selective index of 35. This compound was subsequently evaluated for apoptosis induction in MDA-MB-231 cells, using GI50 and 50% lethal concentrations (LC50). Flow cytometry analysis showed that at LC50 compound 3 induced cell death with phosphatidylserine externalization and caspase-3 activation. Apoptotic genes were measured by RT-qPCR, revealing an upregulation of BAX, with an increase in expression of the BAX/BCL2 ratio in treated cells. Fluorescence microscopy disclosed morphological changes related to apoptosis. Overall, these findings showed compound 3 to be a promising prototype against TNBC cells that tend to respond poorly to conventional therapies.

Myricitrin from Combretum lanceolatum Exhibits Inhibitory Effect on DNA-Topoisomerase Type IIα and Protective Effect Against In Vivo Doxorubicin-Induced Mutagenicity.

Flavonoids-compounds abundant in balanced daily diets-have been extensively investigated for biological activity. The pronounced antiproliferative effects of flavonoids have prompted studies to elucidate their mode of action against tumor cells. The anticancer properties of myricetin, a 3',4',5'-tri-hydroxylated flavonol, have been confirmed for a number of neoplasms, but myricitrin, its 3-O-rhamnoside derivative found in fruits and other parts of edible plants, has been scarcely investigated as a chemopreventive agent. This study evaluated the antiproliferative potential of myricitrin obtained from Combretum lanceolatum (Combretaceae) against MCF7 (breast), PC-3 (prostate), HT-29 (colon), 786-0 (kidney), and HL-60 (acute promyelocytic leukemia) cancer cell lines, using the sulforhodamine B and tetrazolium salt assays. Myricitrin proved most effective in inhibiting growth of HL-60 cells (GI50 = 53.4 µmol·L-1), yet showed weak antiproliferative activity against other cell lines. Possible cytotoxic mechanisms involving inhibition of topoisomerases I and IIα by myricitrin were also evaluated, revealing inhibitory activity only against topoisomerase IIα. The results suggested that topoisomerase IIα inhibition is the probable mechanism responsible for the antiproliferative activity of myricitrin. In vivo mutagenicity by myricitrin and its possible antimutagenic effect on doxorubicin-induced DNA damage were also investigated by performing the somatic mutation and recombination test (SMART) on Drosophila melanogaster. Myricitrin proved nonmutagenic to the offspring of standard (ST) and high-bioactivation (HB) crosses, while cotreatments with doxorubicin revealed the antimutagenic properties of myricitrin, even under conditions of high metabolic activation.

Evaluation of the Antitumor Potential of the Resorcinolic Lipid 3-Heptyl-3,4,6-trimethoxy-3H-isobenzofuran-1-one in Breast Cancer Cells.

BACKGROUND/AIM: In recent years, the search for new anticancer experimental agents derived from natural products or synthetic analogues, such as resorcinolic lipids, has received increased attention. The present study aimed to evaluate the antitumor potential, describe the cell death mechanism and the effects of 3-Heptyl-3,4,6-trimethoxy-3Hisobenzofuran-1-one (AMS35AA) in combination with different chemotherapeutic agents in the MCF-7 cell line. MATERIALS AND METHODS: Analysis of cytotoxic, genotoxic, membrane integrity, cell death and gene expression induced by the compound was performed. RESULTS: The AMS35AA and its association with 5-FU demonstrated reduction of cell viability; increase of cell death; enhancement of genomic damage and accumulation of cells in G2/M phase. CONCLUSION: AMS35AA has potential for breast cancer treatment since it is capable of exerting cytotoxic and cytostatic effects in a breast cell line and also could be an adjuvant in cancer therapy when combined with 5-FU.

Isolation and molecular characterization of Leishmania infantum in urine from patients with visceral leishmaniasis in Brazil.

Leishmania infantum is a protozoan that causes visceral leishmaniasis, a potentially deadly neglected tropical disease. The gold standard for diagnosis has traditionally been detection of amastigotes in bone marrow or spleen aspirates, but this is an invasive procedure that carries the risk of serious complications. Newer PCR techniques are opening new avenues and tissues for testing. Therefore, we tested if amastigotes and DNA from L. infantum could be detected in patient urine. We detected L. infantum DNA in six out of 30 urine samples from patients with visceral leishmaniasis and the promastigotes were isolated in culture from the urine of one patient. These results suggest the feasibility of using urine samples to diagnose visceral leishmaniasis, especially in acute cases or renal infection, providing a valuable tool for doctors and clinicians to use for screening and diagnosis of leishmaniasis in patients.

Molecular characterization of Leishmania infantum in domestic cats in a region of Brazil endemic for human and canine visceral leishmaniasis.

Leishmaniasis is a "neglected tropical disease" and serious public health issue in Brazil. While dogs are recognized as particularly important reservoirs, recent reports of domestic cats infected with Leishmania sp. in urban areas suggest their participation in the epidemiological chain of the parasite in endemic areas. The aim of this study was to screen domestic cats for Leishmania sp. infection in an area where human and canine visceral leishmaniasis are endemic, followed by the identification of the species circulating in cats. We collected peripheral blood, lymph-node aspirates and bone marrow from 100 adult animals, both male and female, and analyzed the samples using cytological and molecular (PCR) detection techniques. We detected Leishmania in 6% of animals, which were then analyzed by RFLP-PCR to identify the species. Leishmania infantum (synonym: L. chagasi), a species responsible for visceral leishmaniasis in humans and other animals, was identified from all six samples. Amastigotes were observed in the peripheral blood, bone marrow and lymph-node aspirates in 4 of the 6 PCR-positive animals. The presence of infected cats in endemic areas should not be neglected, because it demonstrates the potential role of these animals in the biological cycle of the pathogen.

Further constituents of Galianthe thalictroides (Rubiaceae) and inhibition of DNA topoisomerases I and IIα by its cytotoxic ß-carboline alkaloids.

A new cytotoxic ß-carboline alkaloid, 1-methyl-3-(2-hydroxypropan-2-yl)-2-(5-methoxy-9H-ß-carbolin-1-yl)-cyclopentanol (1), was isolated from roots of Galianthe thalictroides, together with the alkaloid 1-(hydroxymethyl)-3-(2-hydroxypropan-2-yl)-2-(5-methoxy-9H-ß-carbolin-1-yl)-cyclopentanol (2), the anthraquinones 1-methyl-alizarin and morindaparvin-A, the coumarin scopoletin, homovanillic alcohol, (-)-epicatechin, and the steroids stigmast-4-en-3-one, 4,22-stigmastadien-3-one, campest-4-en-3-one, stigmast-4-en-3,6-dione, 6-ß-hydroxy-stigmast-4-en-3-one, stigmasterol, campesterol, ß-sitosterol, and ß-sitosterol-3-O-ß-D-glucopyranoside. Among the previously known compounds, homovanillic alcohol is a novel finding in Rubiaceae, while 1-methyl-alizarin, morindaparvin-A, scopoletin, stigmast-4-en-3-one, 4,22-stigmastadien-3-one, campest-4-en-3-one, stigmast-4-en-3,6-dione, and 6-ß-hydroxy-stigmast-4-en-3-one is reported for the first time in the genus Galianthe. The cytotoxic ß-carboline alkaloids 1 and 2 exhibited potent antitopoisomerase I and IIα activities and strong evidence is provided for their action as topoisomerase IIα poisons and redox-independent inhibitors.

Application of Fenton, photo-Fenton, solar photo-Fenton, and UV/H2O2 to degradation of the antineoplastic agent mitoxantrone and toxicological evaluation.

In the present study, selected advanced oxidation processes (AOPs)-namely, photo-Fenton (with Fe(2+), Fe(3+), and potassium ferrioxalate-FeOx-as iron sources), solar photo-Fenton, Fenton, and UV/H2O2-were investigated for degradation of the antineoplastic drug mitoxantrone (MTX), frequently used to treat metastatic breast cancer, skin cancer, and acute leukemia. The results showed that photo-Fenton processes employing Fe(III) and FeOx and the UV/H2O2 process were most efficient for mineralizing MTX, with 77, 82, and 90% of total organic carbon removal, respectively. MTX probably forms a complex with Fe(III), as demonstrated by voltammetric and spectrophotometric measurements. Spectrophotometric titrations suggested that the complex has a 2:1 Fe(3+):MTX stoichiometric ratio and a complexation constant (K) of 1.47 × 10(4) M(-1), indicating high MTX affinity for Fe(3+). Complexation partially inhibits the involvement of iron ions and hence the degradation of MTX during photo-Fenton. The UV/H2O2 process is usually slower than the photo-Fenton process, but, in this study, the UV/H2O2 process proved to be more efficient due to complexing of MTX with Fe(III). The drug exhibited no cytotoxicity against NIH/3T3 mouse embryonic fibroblast cells when oxidized by UV/H2O2 or by UV/H2O2/FeOx at the concentrations tested.

Ixodid fauna and zoonotic agents in ticks from dogs: first report of Rickettsia rickettsii in Rhipicephalus sanguineus in the state of Mato Grosso do Sul, mid-western Brazil.

Ticks from 148 dogs from the urban area of the municipality of Campo Grande, state of Mato Grosso do Sul, Brazil, were collected, classified and analyzed using polymerase chain reaction (PCR) for the identification of Rickettsia spp., Trypanosoma cruzi and Leishmania spp. A total of 2015 ticks were collected. The species Rhipicephalus sanguineus (98.9 %) and Amblyomma cajennense (1.1 %) were identified. Molecular analysis revealed that no tick samples were infected by T. cruzi. Regarding Leishmania spp., tick samples from 36 dogs spread across all regions of the municipality were positive for L. chagasi. One tick sample was positive for Rickettsia spp. (gltA gene) in the PCR reaction. This sample was submitted to further PCR based on the ompA gene and the amplicon was sequenced. Identity of 100 % was found with homologous sequences of R. rickettsii available in GenBank. This paper is the first to report the natural infection of R. sanguineus by R. rickettsii in the municipality of Campo Grande, state of Mato Grosso do Sul, mid-western Brazil.