Flavonoids composition, antioxidant, anticholinesterase, and cytotoxic activities of flowers extract of Senna cearensis Afr. Fern.

The Senna genus has a wide diversity of species, with an interesting chemical composition of secondary metabolites and applications as medicine. The folk medicine, mainly in developing countries, uses species of Senna to treat seizures, epilepsy and constipation. Though the recognized bioactivity, some Brazilian native species of Senna remain unexplored, such as Senna cearensis, a native species of Caatinga. This is the first report about the bioactivity of the flowers of S. cearensis Afr. Fern., a native species of northeast Brazil. In this communication, flavonoids and catechins are identified in S. cearensis flowers and the chemical composition is linked with its antioxidant, anticholinesterase, and cytotoxic activities. By UPLC-QTOF, some compounds that belong to the class of flavonoids were identified. They are: catechin, epigallocatechin, guibourtinidol-(4α-8)-catechin, and cassiaflavan-(Cat)-epicatechin. The cytotoxic activity is more noticeable for the HL60 (leukemia) cell line with a cell growth inhibition (GI%) of 81.65 ± 5.65.

Chemical composition, in vitro cytotoxic and anticholinesterase activities of flower extracts of Senna spectabilis var. excelsa and Senna macranthera.

In this study, we investigated the phenolic and antioxidant content, cytotoxic, and anticholinesterase activities of flower extracts of Senna spectabilis var. excelsa and Senna macranthera. The antioxidant activities performed by the DPPH and ABTS methods showed that the extracts possess good antioxidant activity, with emphasis on the S. macranthera extract, which obtained results very similar to the rutin pattern. In the evaluation of the cytotoxic activity, the species S. spectabilis var. excelsa presented expressive cytotoxicity against the cellular lines PC3 and HL60 with IC50 values 21.08 and 31.37 µg mL-1, respectively. The results of anticholinesterase activity showed that both the plants induced enzyme inhibition, reaching 14 mm of inhibition in the case of S. spectabilis var. excelsa. The good results obtained in this work may be related to the presence of compounds such as apigenin-7-apioglucoside, quercetin 3,4'-diglucoside, cassine and spectaline identified in the extracts in our previous work.

Hydrazones derived from natural aldehydes: in vitro cytotoxic evaluation and in silico pharmacokinetic predictions / Hidrazonas derivadas de aldehídos naturales: evaluación citotóxica in vitro y determinación del perfil farmacocinético in silico / Hidrazonas derivadas de aldeídos naturais: avaliação citotóxica in vitro e determinação de perfil farmacocinético in silico

SUMMARY Introduction: Recent research has reported the cytotoxic potential of hydrazones against various strains of cancer cells. Aim: To evaluate the anticancer activity in vitro and the pharmacokinetic profile of six synthesized hydrazonic compounds, identified as vanillin 1-phthalazinylhydrazone (VAN-1); 2,4-dinitrophenylhydra-zone vanillin (VAN-2); phenylhydrazone cinnamaldehyde (CIN-1); isonicotinoyl hydrazone cinnamaldehyde (CIN-2); cinnamaldehyde 1-phthalazinylhydrazone (CIN-3); and 2,4-dinitrophenylhydrazone cinnamaldehyde (CIN-4). The cytotoxic activity was evaluated against four strains of cancer cells. Methodology: The pharmacokinetic parameters of absorption, distribution, metabolism, excretion, and toxicity (ADME/T) of the hydrazones were evaluated using the PreADMET program. Results: Hydrazones derived from cinnamaldehyde (CIN-1 and CIN-2) showed high cytotoxic activity against leukemic (HL-60) and glioblastomas (SF-295) cell lines. The pharmacokinetic profile of the hydrazones showed that, in general, the hydrazones presented satisfactory characteristics of ADME/T. In addition, it was observed that CIN-2 presented the most promising in silico profile, showing high intestinal absorption, desirable distribution profile related to plasma protein binding, adequate renal excretion, and low toxicity. The ADME/T profile of the CIN-1 compound highlighted its potential as a promising antineoplastic agent with action of the CNS, more specifically against glioblastomas.

RESUMEN Introducción: Investigaciones recientes han informado del potencial citotóxico de las hidrazonas contra varias líneas de células cancerosas. Objetivo: Evaluar la actividad anticancerígena in vitro y el perfil farmacocinético de seis compuestos hidrazónicos sintetizados, identificados como vainillina 1-ftalazinilhidrazona (VAN-1); vainillina 2,4-dinitrofenilhidrazona (VAN-2); fenilhidrazona cinamal-dehído (CIN-1); cinamaldehído de isonicotinoil hidrazona (CIN-2); cinamalde-hído 1-ftalazinilhidrazona (CIN-3); y 2,4-dinitrofenilhidrazona cinamaldehído (CIN-4). Se evaluó la actividad citotóxica frente a cuatro líneas celulares cancerosas. Metodología: Los parámetros farmacocinéticos de absorción, distribución, metabolismo, excreción y toxicidad (ADME/T) de las hidrazonas se evaluaron mediante el programa PreADMET. Resultados: Las hidrazonas derivadas del cinamaldehído (CIN-1 y CIN-2) mostraron una alta actividad citotóxica contra las líneas celulares leucémicas (HL-60) y glioblastomas (SF-295). El perfil farmacocinético de las hidrazonas mostró que, en general, las hidrazonas mostraban características satisfactorias de ADME/T. Además, se observó que CIN-2 presentó el perfil in silico más prometedor, presentando alta absorción intestinal, perfil de distribución deseable relacionado con la unión a proteínas plasmáticas, excreción renal adecuada y baja toxicidad. El perfil ADME/T del compuesto CIN-1 destacó su potencial como agente antineoplásico prometedor con acción sobre el SNC, más específicamente contra los glioblastomas.

RESUMO Introdução: Pesquisas recentes relataram o potencial citotóxico das hidrazonas contra várias linhagens de células cancerígenas. Objetivo: Validara atividade anti-câncer in vitro e o perfil farmacocinético de seis compostos hidrazônicos sintetizados, identificados como vanilina 1-ftalazinil-hidrazona (VAN-1); vanilina 2,4-dinitrofenil-hidrazona (VAN-2); cinnamaldeído de fenil-hidrazona (CIN-1); cinamaldeído isonicotinoil-hidrazona (CIN-2); 1-ftalazinil-hidrazona de cinnamaldeído (CIN-3); e cinamaldeído de 2,4-dinitrofenil-hidrazona (CIN-4). A atividade citotóxica foi avaliada contra quatro linhagens de células cancerígenas. Metodologia: Os parâmetros farmacocinéticos de absorção, distribuição, metabolismo, excreção e toxicidade (ADME/T) das hidrazonas foram avaliados utilizando o programa PreADMET. Resulados: As hidrazonas derivadas do cinnamaldeído (CIN-1 e CIN-2) apresentaram alta atividade citotóxica contra as linhagens celulares leucêmicas (HL-60) e de glioblastomas (SF-295). O perfil farmacocinético das hidrazonas mostrou que, em geral, as hidrazonas apresentaram características satisfatórias de ADME/T. Além disso, observou-se que a CIN-2 apresentou o perfil in silico mais promissor, exibindo alta absorção intestinal, perfil de distribuição desejável relacionado à ligação às proteínas plasmáticas, excreção renal adequada e baixa toxicidade. O perfil ADME/T do composto CIN-1 destacou seu potencial como um agente antineoplásico promissor com ação do SNC, mais especificamente contra glioblastomas.

Diphenyl Ditelluride: Redox-Modulating and Antiproliferative Properties.

Tellurium is a rare element that has been regarded as a toxic, nonessential element, and its biological role is not clearly established. In addition, the biological effects of elemental tellurium and some of its organic and inorganic derivatives have been studied, leading to a set of interesting and promising applications. Diphenyl ditelluride (DPDT), an organic tellurium derivate, showed antioxidant, antigenotoxic, antimutagenic, and anticancer properties. The antioxidant and prooxidant properties of DPDT are complex and depend on experimental conditions, which may explain the contradictory reports of these properties. In addition, DPDT may exert its effects through different pathways, including distinct ones to those responsible for chemotherapy resistance phenotypes: transcription factors, membrane receptors, adhesion, structural molecules, cell cycle regulatory components, and apoptosis pathways. This review aims to present recent advances in our understanding of the biological effects, therapeutic potential, and safety of DPDT treatment. Moreover, original results demonstrating the cytotoxic effects of DPDT in different mammalian cell lines and systems biology analysis are included, and emerging approaches for possible future applications are inferred.

Synthesis and Antibacterial Activity of Mefloquine-Based Analogs Against Sensitive and Resistant Mycobacterium tuberculosis Strains.

Background and Introduction: Mefloquine, a drug used to prevent and treat malaria is described possessing activity against the Mycobacterium tuberculosis (Mtb) as well as against multidrugresistant tuberculosis (MDR) and other types of bacteria. Despite their importance, few compounds based on the Mefloquine nucleus have been synthesized and evaluated against TB. MATERIALS AND METHODS: For the synthesis of all the compounds based on the Mefloquine nucleus we used a synthetic route which utilized the key derivative 4-methoxy-2,8-bis(trifluoromethyl)quinoline 2 as starting material. The compounds 3 (a-c), 4 (a-b) were synthesized after one step by reaction of 2 with appropriate amines substituted. The chloro derivatives 5 and 6 were obtained from compounds 4b and 4a by treatment with SOCl2 in CH2Cl2 at reflux in 75 and 80% yield, respectively. The analogue 6 was converted to 7 after treatment with ethanolamine under heating at 90oC in 64% yield and to the azido derivative 8 in 56% after reaction with sodium azide in MeOH at reflux for 2 h. The analogue 9 was obtained after reaction of 5 with ethanolamine at 90oC for 1 h in 90% yield. All the new compounds were identified by detailed spectral data, including 1H NMR, 13C NMR and high resolution mass spectra. All the compound were evaluated for their in vitro antibacterial activity against sensitive Mycobacterium tuberculosis ATCC 27294, using the microplate Alamar Blue assay (MABA). The more active compounds 3c, 7, and 9 were also evaluated against resistant strain SR 2571/0215 (resistant to Rifampicin and Isoniazid) by above method. All compounds were tested against three cancer cell lines: SF-295 (glioblastoma), HCT-116 (colon) and PC-3 (prostate) using the MTT assay. RESULTS: All the planned ten compounds were synthetically obtained in good global yield, displaying activity against sensitive Mycobacterium tuberculosis in vitro, with exception of one, with MIC values between 37.2 and 154.8 µM. The compounds 3c (37.2 µM), 7 (68.1 µM) and 9 (65.6 µM) showed the highest activity in this series with MIC values similar when compare to the standard Mefloquine (30 - 60 µM), being 3c the most potent. The more active compounds 3c, 7, and 9 were also evaluated against resistant strain, displaying MIC of 37.2, 136.2 and 65.6 µM, respectively. All compounds were tested against three cancer cell lines and showed low cytotoxicity. CONCLUSION: All synthesized compounds, with the exception of 5, exhibited activity against the Mtb. Compound 3c was the most potent against resistant and sensitive Mtb in this series, with MIC value of 37.2 µM. All compounds showed low cytotoxicity. These findings could be considered a good model to develop possible lead compounds in the fight against TB based on Mefloquine nucleus.

In vivo antitumor effect, induction of apoptosis and safety of Remirea maritima Aubl. (Cyperaceae) extracts.

BACKGROUND: Remirea maritima has been widely used in the treatment of diarrhea, kidney disease, and high fever and for therapeutic purposes, such as an analgesic and anti-inflammatory. However, few scientific research studies on its medicinal properties have been reported. PURPOSE: The present study aimed to investigate the anticancer potential of aqueous extract (AE), 40% hydroalcoholic extracts (40HA) and 70% (70HA) from R. maritima in experimental models and to identify its phytochemical compounds. METHODS: The chemical composition of AE, 40HA and 70HA was assessed by HPLC-DAD and ESI-IT-MS/MS. In vitro activity was determined on cultured tumor cell, NCI-H385N (Broncho-alveolar carcinoma), OVCAR-8 (Ovarian carcinoma) and PC-3M (prostate carcinoma) by the MTT assay, and the in vivo antitumor activity was assessed in Sarcoma 180-bearing mice. Toxicological parameters were also evaluated as well as the humoral immune response. RESULTS: Among the aqueous and hydroalcoholic extracts of R. maritima, only 40HA showed in vitro biological effect potential, presenting IC50 values of 27.08, 46.62 and >50µg/ml for OVCAR-8, NCI-H385M and PC-3M cells lines, respectively. Regarding chemical composition, a mixture of isovitexin-2''-O-ß-D-glucopyranoside, vitexin-2''-O-ß-D-glucopyranoside, luteolin-7-O-glucuronide and 1-O-(E)-caffeoyl-ß-D-glucose were identified as the major phytochemical compounds of the extracts. In the in vivo study, the tumor inhibition rates were 57.16-62.57% at doses of 25mg/kg and 50mg/kg, respectively, and the tumor morphology presented increasing numbers of apoptotic cells. Additionally, 40HA also demonstrated significantly increased of OVA-specific total Ig. CONCLUSIONS: 40HA exhibited in vitro and in vivo anticancer properties without substantial toxicity that could be associated with its immunostimulating properties.

Evaluation of the cytotoxic and antitumour effects of the essential oil from Mentha x villosa and its main compound, rotundifolone.

OBJECTIVES: The aim of this study was to investigate the cytotoxic and antitumour effects of the essential oil from the leaves of Mentha x villosa (EOMV) and its main component (rotundifolone). METHODS: In-vitro cytotoxic activity of the EOMV and rotundifolone was determined on cultured tumour cells. In-vivo antitumour activity of the EOMV was assessed in sarcoma 180-bearing mice. KEY FINDINGS: The EOMV displayed cytotoxicity against human tumour cell lines, showing IC50 values in the range of 0.57-1.02 µg/ml in the HCT-116 and SF-295 cell lines, respectively. Rotundifolone showed weak cytotoxicity against HCT-116, SF-295 and OVCAR-8 cell lines (IC50 > 25.00 µg/ml). Tumour growth inhibition rates were 29.4-40.5% and 25.0-45.2% for the EOMV treatment by intraperitoneal (50-100 mg/kg/day) and oral (100-200 mg/kg/day) administration, respectively. The EOMV did not significantly affect body mass and macroscopy of the organs. CONCLUSIONS: The EOMV possesses significant antitumour activity with low systemic toxicity, possibly due to the synergistic action of its minor constituents.

Mauritic acid: a new dammarane triterpene from the roots of Mauritia flexuosa L.f. (Arecaceae).

A new dammarane triterpene named mauritic acid (1) was isolated from the roots of Mauritia flexuosa L.f. The complete structural assignment of this new compound was elucidated from spectroscopic methods. Moreover, this compound was evaluated for its cytotoxicity against human cancer cell lines (OVCAR-8, PCM3, NCIH358M and different leukaemia cell strains). The mauritic acid presented significant cytotoxicity against OVCAR-8, PCM3 and NCIH358M cell lines with IC50 3.02, 2.39 and 6.19 µM, respectively. The triterpenes 1 and 2 were also tested for their antimicrobial activity against 15 strains of microorganisms, including fungi and bacteria, with the best minimal inhibitory concentration values ranging from 50.8 to 203.5 µM.

Comet assay and micronucleus test in circulating erythrocytes of Aequidens tetramerus exposed to methylmercury.

BACKGROUND: Comet assay and micronucleus test have been used increasingly to evaluate the genotoxicity of many metals and their organic compounds in aquatic ecosystems. The use of endemic aquatic organisms as biological sentinels has proved useful in environmental monitoring. In this study, the genetic damage caused by methylmercury (MeHg) in Aequidens tetramerus (commonly called acará-sela) was assessed using the comet assay and by testing for micronucleus and other nuclear abnormalities. MATERIALS AND METHODS: Specimens were acclimatized in individual aquariums to laboratory conditions and then exposed to 2 mg l(-1)MeHg. Peripheral blood samples were obtained from specimens of A. tetramerus and subjected to the comet and micronucleus assays. RESULTS: The comet assay showed a significant increase of tailed nucleoids in the erythrocytes of fish treated with MeHg (p<0.0001). Our results in the micronucleus test also indicated that MeHg is potentially mutagenic (p<0.003), with more nuclear morphological alterations than typical micronuclei. CONCLUSION: The combination of both assays - comet and micronucleus - is adequate and advantageous for genotoxicity evaluation. The level of damage detected by comet assay was higher than that found in the micronucleus test and the damage index increased with a longer exposure of fish to this xenobiotic; such damage is often not inherited by future cellular generations and, for this reason, cannot be detected by the micronucleus assay. Our results also demonstrated that A. tetramerus is an adequate model for biological studies that evaluate genotoxic effects in aquatic environments.

Cytotoxic profile of natural and some modified bufadienolides from toad Rhinella schneideri parotoid gland secretion.

Cutaneous secretions of toad species are an important source of bufadienolides, compounds that exhibit interesting structural features and biopharmacological properties. Here we describe the isolation of bufadienolides from the Brazilian toad Rhinella schneideri parotoid glands secretion, including: marinobufagin (1), bufalin (2), telocinobufagin (3), hellebrigenin (4), and the atypical 20S,21R-epoxymarinobufagin (5) besides the widespread beta-sitosterol (6). Starting from natural bufadienolides four derivatives were prepared: 3beta-acetoxy-marinobufagin (7), 3beta-acetoxy-bufalin (8), 3beta-acetoxy-telocinobufagin (9), and 3beta-acetoxy-20S,21R-epoxymarinobufagin (10). The cytotoxic evaluation showed that all natural bufadienolides and their derivatives exhibited moderate to strong activity against human HL-60, SF-295, MDA-MB-435, and HCT-8 cancer cell strains without hemolysis of mouse erythrocytes. The acetylated bufadienolides (7-9) and the epoxide 10 showed lesser peripheral blood lymphocytes (PBLs) inhibitory activity than their precursors, suggesting that chemical modifications on such compounds can play an important role on the modulation of their cytotoxic profile.

New antimalarial and cytotoxic 4-nerolidylcatechol derivatives.

4-Nerolidylcatechol (1) was isolated from cultivated Pothomorphe peltata root on a multigram scale using straight-forward solvent extraction-column chromatography. New semi-synthetic derivatives of 1 were prepared and tested in vitro against multidrug-resistant Plasmodium falciparum K1 strain. Mono-O-methyl, mono-O-benzyl, O,O-dibenzyl and O,O-dibenzoyl derivatives 2-8 exhibited IC(50) in the 0.67-22.52 microM range. Mono-O-methyl ethers 6 and 7 inhibited the in vitro growth of human tumor cell lines HCT-8 (colon carcinoma), SF-295 (central nervous system), LH-60 (human myeloblastic leukemia) and MDA/MB-435 (melanoma). In general, derivatives 2-8 are more stable to light, air and pH at ambient temperatures than their labile, natural precursor 1. These derivatives provide leads for the development of a novel class of antimalarial drugs with enhanced chemical and pharmacological properties.

Cytotoxic alkylpiperidine alkaloids from the Brazilian marine sponge Pachychalina alcaloidifera.

Four bis-piperidine alkaloids, madangamine F (1), haliclonacyclamine F (2). and arenosclerins D (3) and E (4), have been isolated from the marine sponge Pachychalina alcaloidifera and have been identified by analysis of spectroscopic data. The alkaloids displayed cytotoxic activity against different cancer cell lines. These results support the hypothesis of a common biogenetic origin for the Haplosclerida bis-piperidine and bis-pyridine alkaloids.