Specific antitumor activity and mechanism of protonic bis-phenanthroline / 药学学报

Hepatocellular carcinoma (HCC) is a common malignant tumor worldwise. The incidence rate of HCC is high and is easy to metastasis and recurrence, which seriously affects human health. Traditional chemical drugs have some challenges such as toxicity, side effects, and multidrug resistance, thus it is urgent to find new drugs and effective targets. Here we synthesized a novel chemical, protonic bis-phenanthroline (H-BP), and the antitumor effect was investigated in the study. The results showed that H-BP could selectively inhibit the proliferation of tumor cells and cause HCC apoptosis. And also, in HCC tumor-bearing mice, H-BP could effectively prevent the growth of tumor mass, even completely eliminate the tumor at medium dose (5 mg·kg-1) and high dose (10 mg·kg-1), and meanwhile H-BP has no significant effect on the body weight of mice. The experimental protocol was approved by the Animal Ethics Committee of Southwest University, and the experimental operation was strictly carried out in accordance with the ethical principles of animal use and care. Mechanism studies showed that H-BP induced HCC apoptosis was related to down-regulation the expression of pleomorphic adenoma gene like-2 (PLAGL2), a oncogene transcription factor, resulting in the down-regulation of PLAGL2 downstream proteins hypoxia inducible factor and β-catenin. This study not only introduces the dimerization method to form novel compounds that will provide a new approach for drug design, but also suggests that PLAGL2 may be an effective target in tumor therapy.

Effect of potassium bisperoxo (1,10-phenanthroline) oxovanadate on proliferation and cell cycle in HT22 cells / 中国药理学与毒理学杂志

OBJECTIVE To explore whether different concentrations of potassium bisperoxo (1,10-phenanthroline) oxovanadate [BPV (phen)) affect cell cycle by regulating the expression of DNA meth-yltranferases (DNMT) and cell cycle-related genes. METHODS HT22 cells were treated with BPV (phen) 0.3 and 3 μ mol • L-1 for 24 h. The cell viability was detected by MTS assay, cell cycle was detected by flow cytometry, the activity of DNMT was detected by ELISA, the mRNA expressions of p21, DNMT1, DNMT3A and DNMT3B were measured with real-time quantitative PCR, while the levels of corresponding proteins were measured by Western blotting. RESULTS Compared with the DMSO control group, BPV(phen) 0.3 μ mol• L-1 did not affect cell viability, but the cell viability of BPV(phen) 3 pmol-L-1 increased signifi-cantly (P<0.05). There was no significant difference in cell cycle between DMSO control and BPV(phen) 0.3 nmol-L-1 group, but the proportion of cells in S phase increased((76.0±1.6)%)(P<0.05) and in G2 phase decreased ((2.1 ±1.5)%) (P<0.05) of BPV(phen) 3.0 μ mol • L-1 group. The intracellular DNMT activity of BPV(phen) 3.0 Mmol • L-1 group was significantly increased compared with the DMSO control group (F<0.05). There was no significant difference in the mRNA expressions of p21, DNMT1, DNMT3A and DNMT3B between DMSO control and BPV(phen) 0.3 μ mol • L-1 group, but all increased in BPV(phen) 3.0 μ mol • L-1 group (P<0.05, P<0.01). Western blotting results showed that there was no significant difference in the protein expressions of P21, DNMT1, DNMT3A and DNMT3B between DMSO control and BPV (phen) 0.3 μ mol • L-1 group, but only the protein expressions of DNMT3B and P21 of BPV (phen) 3.0 μ mol • L-1 group increased significantly (F<0.05). CONCLUSION BPV(phen) can regulate the expression of downstream and cell cycle-related genes by altering the expression of DNMTs, which in turn affects the growth and proliferation of HT22 cells.

In Vitro Antifungal Activity of (1)-N-2-Methoxybenzyl-1,10-phenanthrolinium Bromide against Candida albicans and Its Effects on Membrane Integrity

Metal-based drugs, such as 1,10-phenanthroline, have demonstrated anticancer, antifungal and antiplasmodium activities. One of the 1,10-phenanthroline derivatives compounds (1)-N-2-methoxybenzyl-1,10-phenanthrolinium bromide (FEN), which has been demonstrated an inhibitory effect on the growth of Candida spp. This study aimed to explore the in vitro antifungal activity of FEN and its effect on the membrane integrity of Candida albicans. The minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC) of FEN against planktonic C. albicans cells were determined using the broth microdilution method according to the Clinical and Laboratory Standards Institute guidelines. Cell membrane integrity was determined with the propidium iodide assay using a flow cytometer and were visualized using scanning electron microscopy (SEM). Planktonic cells growth of C. albicans were inhibited by FEN, with an MIC of 0.39–1.56 µg/mL and a MFC that ranged from 3.125 to 100 µg/mL. When C. albicans was exposed to FEN, the uptake of propidium iodide was increased, which indicated that membrane disruption is the probable mode of action of this compound. There was cells surface changes of C. albicans when observed under SEM.

The effect of inhibitors on photosynthetic electron transport chain in canola leaf discs / Efeito de inibidores na cadeia de transporte de elétrons fotossintética em discos foliares de canola

The mechanisms of photosynthetic electron transport can be elucidated by inhibition of electron flow through the use of specific substances that, when combined with the chlorophyll chlorophyll a fluorescence emission was measured to investigate the effect of several inhibitors of the photosynthetic electron transport chain in canola leaf discs. Leaf discs were incubated in the dark for 2 hours in different solutions: (a) water ­ control; (b) DCMU at 500 µM; (c) phenanthroline at 10 mM; and (d) hydroxylamine at 10, 50, 100 and 200 mM. Similar effects were observed between DCMU and phenanthroline, the initial fluorescence value was altered, but not the maximum fluorescence, with the disappearance of the IP phase. Hydroxylamine interacted and inhibited the oxygen evolving complex and caused an imbalance between the rate of QA reduction by photosystem II and the rate of QA oxidation by photosystem I.

Os mecanismos de transporte de elétrons podem ser elucidados pela inibição do fluxo de elétrons pelo uso de substâncias específicas que, juntamente com a técnica de fluorescência da clorofila, torna-se uma ferramenta importante para detalhar a cadeia de transporte de elétrons. Neste trabalho, a emissão da fluorescência da clorofila foi mensurada para investigar o efeito dos diferentes inibidores da cadeia de transporte de elétrons fotossintéticos de discos foliares de canola. Os discos foliares foram incubados no escuro durante 02 h em diferentes soluções: (a) água - controle, (b) 500 uM de DCMU, (c) 10 mM de fenantrolina, e (d) 10, 50, 100 e 200 mM de hidroxilamina. Foram observados efeitos similares entre DCMU e fenantrolina, o valor da fluorescência inicial foi alterado, contudo a fluorescência máxima não se alterou, havendo o desaparecimento da fase de IP. Hidroxilamina interagiu e inibiu o complexo de evolução de oxigênio e causou desequilíbrio entre a taxa de redução QA pelo fotossistema II e a taxa de oxidação QA pelo fotossistema I.

Trichomonas vaginalis Metalloproteinase Induces mTOR Cleavage of SiHa Cells

Trichomonas vaginalis secretes a number of proteases which are suspected to be the cause of pathogenesis; however, little is understood how they manipulate host cells. The mammalian target of rapamycin (mTOR) regulates cell growth, cell proliferation, cell motility, cell survival, protein synthesis, and transcription. We detected various types of metalloproteinases including GP63 protein from T. vaginalis trophozoites, and T. vaginalis GP63 metalloproteinase was confirmed by sequencing and western blot. When SiHa cells were stimulated with live T. vaginalis, T. vaginalis excretory-secretory products (ESP) or T. vaginalis lysate, live T. vaginalis and T. vaginalis ESP induced the mTOR cleavage in both time- and parasite load-dependent manner, but T. vaginalis lysate did not. Pretreatment of T. vaginalis with a metalloproteinase inhibitor, 1,10-phenanthroline, completely disappeared the mTOR cleavage in SiHa cells. Collectively, T. vaginalis metallopeptidase induces host cell mTOR cleavage, which may be related to survival of the parasite.

Comparison of disc and MIC reduction methods with polymerase chain reaction for the detection of metallo-β-lactamase in Pseudomonas aeruginosa.

Purpose: The present study was undertaken to evaluate the screening antibiotic, confirmatory phenotypic test and agent against PCR as gold standard and to detect the prevalent MBL gene. Materials and Methods: Three hundred and twenty-six Pseudomonas aeruginosa isolates were screened for resistance to Imipenem (IPM), Meropemem (MEM) and Ceftazidime (CAZ) by disc diffusion. Isolates resistant to any of these were considered screen test-positive for MBL and were subjected to Double disc synergy test (DDST) and Disc potentiation test (DPT: Using IPM, MEM and CAZ alone and with EDTA), Minimum inhibitory concentration (MIC) reduction [four-fold or more reduction in MIC of IPM and MEM in presence of chelators: EDTA and 1,10-phenanthroline (EPI/EPM: EDTA-phenanthroline- Imipenem/Meropenem Broth Microdilution method)] and polymerase chain reaction (PCR) for blaIMP and blaVIM . Results: Screen test-positives by MEM and CAZ were 19.3% as against 17.8% by IPM. MEMDDST, DPT and EPM confirmed 100% screen-test positives as against 93.7% by CAZ DDST and DPT-2, 76.2% by CAZ DPT-1, 88.9% by IPM DDST, 85.7% by IPM DPT-1 and 92.1% by EPI. IPMand CAZ DDST together confirmed 100% while IPM and CAZ DPT-2 confirmed 96.8%. All 63 screen-test positives showed the presence of blaVIM . Conclusions: MEM was found to be the best screening and confirmatory agent for MBL detection and blaVIM was found to be the prevalent MBL gene in this part of the country.

Development and validation of spectrophotometric and spectrofluorimetric methods for simultaneous determination of Tofisopam.

Two simple, rapid and accurate spectrophotometric and spectrofluorimetric methods developed for the determination of Tofisopam (TF) in pure form and in pharmaceutical formulation. The spectrophotometric method (A) is based on the reduction of ferric into ferrous in presence of 1, 10-phenanthroline to give an orange –red colored ferroin complex measured at 510 nm. Method (B) spectrofluorimetric method is based on the oxidative coupling reaction of TF with 3-methylbenzothiazolin-2-one hydrazone (MBTH) hydrochloride in presence of cerium (IV) ammonium sulfate in an acidic medium. The quenching effect of TF on the fluorescence of excess cerous ions is measured at the emission λem 345 nm with excitation λex at 296 nm. The factors affecting the reactions were carefully studied and optimized. Beer,s law is obeyed in the range of 2-12 μg ml-1 for both methods with the mean percentages recovery of 100.04 ± 0.445 and 99.29 ± 0.563 for method (A) and (B), respectively. The two proposed methods were successfully applied for the determination of TF in Nodeprine tablets. Statistical comparison between the results obtained by these methods and that obtained by the official method for the determination of the drug was done, and it was found that there was no significant differences between them.

EVALUACIÓN DE LA ACTIVIDAD CITOTÓXICA Y ANTIMICROBIANA DEL COMPUESTO [Ag(phen)2]salH) / EVALUATION OF THE CITOTOXICITY AND ANTIMICROBIAL ACTIVITY OF THE [Ag(phen)2]salH COMPOUND / AVALIAÇÂO DA ACTIVIDADE CITOTÓXICA E ANTIMICROBIANA DO COMPOSTO [Ag(phen)2]salH

En este artículo se evaluó la actividad antimicrobiana y citotóxica de un nuevo complejo de plata(I) con el ión salicilato y 1,10-fenantrolina. La caracterización de este compuesto se realizó por espectroscopia de resonancia magnética nuclear de protón y carbono-13 (RMN ¹H y 13C), espectroscopia de absorción en la región de infrarrojo (IR), análisis térmico (TG/DSC) y análisis elemental (CHN). Los resultados obtenidos a través de estos métodos sugieren la formación del compuesto con fórmula empírica [Ag(phen)2] salH. Cuando fue comparada la actividad antimicrobiana y citotóxica de este complejo con otros compuestos de plata(I) y cobre(II) de actividad conocida, se observó que el ligante 1,10-fenantrolina incrementa estas propiedades. El compuesto en estudio, presenta la mayor inhibición del crecimiento bacteriano, los microorganismos Gram positivos fueron los más susceptibles. La actividad citotóxica fue evaluada en un panel de cinco líneas celulares tumorales humanas: MDA-MB231, PC-3, HT-29, HEp-2 y A549. A las concentraciones evaluadas, el compuesto produjo una respuesta citotóxica dosis-dependiente en todas las líneas celulares tumorales, particularmente para las líneas tumorales HT-29, MDA-MB231 y A549. Todo esto, sugiere su gran potencial para usos quimioterapéuticos.

This article evaluated the antimicrobial and cytotoxic activity of a new complex of silver(I) with the salicylate ion and 1,10-phenanthroline. The characteriza-tion of this compounds was performed by nuclear magnetic resonance spectroscopy of proton and carbon-13 (RMN ¹H y 13C), spectroscopy absorption in the infrared (IR), thermal analysis (TG/DCS) and elemental analysis (CHN). The results ob-tained through these methods suggest the formation of the compound with empiri-cal formula Ag(phen)2]salH 4. When was compared the antimicrobial activity and cytotoxicity of the complex with other compounds of silver(I) and copper(II) of known activity, we observed that 1, 10-phenalthroline ligand increases these properties. The compound under study has the highest inhibition of bacterial growth, Gram-positive microorganisms were the most susceptible. The cytotoxic activity was tested against a panel of fve human cancer cell lines: MDA-MB231, PC-3, HT-29, HEp-2 and A549. At the concentrations tested, the compound pro-duced a dose-dependent cytotoxic res-ponse against all tumor cell lines, parti-cularly against the HT-29, MDA-MB231 and A549 cell lines. All this suggests its potential chemotherapeutic use.

Neste artigo avaliou-se a atividade antimicrobiana e citotóxica de um novo complexo de prata(I) com o íon sali-cilato e 1,10-fenantrolina. A caracterização deste composto foi realizada por espectroscopia de ressonância magnética nuclear de próton e carbono-13 (RMN ¹H e 13C), espectroscopia de absorção na região de infravermelho (IV), análise térmico (TG/DSC), análi-se elementar (CHN). Os resultados ob-tidos através destes métodos sugerem a formação do composto com fórmula empírica [Ag(phen)2]salH. Quando foi comparada a atividade antimicrobiana e citotóxica deste complexo com outros compostos de prata(I) e cobre(II) de ati-vidade conhecida, observou-se que o ligante 1,10-fenantrolina aumenta essas propriedades. O composto em estudo apresenta maior inibição do crescimento bacteriano, os microorganismos Gram-positivos foram os mais suscetíveis. A atividade citotóxica foi avaliada em um painel de cinco linhas de células tu-morais humanas: MDA-MB231, PC-3, HT-29, HEp-2 e A549. Com as concen-trações avaliadas, o composto deu uma resposta citotóxica dose-dependência em todas as linhagens de células tumo-rais, particularmente para as linhas de células tumorais HT-29, MDA-MB231 e A549. Tudo isso, sugere, um grande potencial para aplicações em quimioterapia.

Efeito da 1, 10-fenantrolina e seus derivados complexados em metal na atividade proteolítica de Leishmania braziliensis / Effect of 1, 10-phenanthroline and its complexed metal derivatives in proteolytic activity of Leishmania braziliensis

Leishmanioses são um grupo de doenças com um largo espectro de manifestações clínicas, as quais variam desde lesões cutâneas até o envolvimento visceral severo, podendo levar ao ótibo. A leishmaniose é, ainda hoje, uma doença negligenciada, estando entre os agravos prioritários do programa de pesquisa sobre doenças da pobreza da Organização Mundial da Saúde (OMS). Além de não haver vacinas disponíveis, a terapia é baseada em medicamentos injetáveis que causam sérios efeitos colaterais, tornando o tratamento inviável para muitos países endêmicos. Drogas derivadas de metal representam um novo arsenal terapêutico antimicrobiano e anti-câncer. Os inibidores de peptidase/agentes quelantes tais como 1,10-fenantrolina e seus derivados, no estado livre de metal ou como ligantes com metais de transição, interferem com a função de vários sistemas biológicos. Em trabalhos anteriores, nosso grupo descreveu que o parasito L. braziliensis produziu moléculas gp63 sensíveis a 1,10-fenantrolina. No presente trabalho, demonstramos a distribuição celular da molécula gp63 em uma cepa virulenta de L. braziliensis por meio de análises bioquímicas e imuno-histoquímica. Depois disso, relatamos os efeitos inibitórios de três compostos derivados da 1,10-fenantrolina, 1,10-fenantrolina-5,6-dioma (phendio), [Cu(phendio)2] e [Ag(phendio)2], nas atividades metalopeptidases celulares e extracelulares produzidas por promastigotas de L. braziliensis, bem como as suas ações sobre a viabilidade do parasita e na interação com as células de macrófagos murinos. As moléculas gp63 foram detectadas em compartimentos de parasitos, incluindo membrana citoplasmatica e bolsa flagelar. O tratamento de promastigotas de L. braziliensis durante 1 hora com 1,10-fenantrolina e seus derivados resultou numa inibição significativa da viabilidade celular e mostrou um mecanismo de ação irreversível. Estes inibidores de metalopeptidases induziram apoptose em promastigotas de L. braziliensis, demonstrada através ...

Leishmaniasis is a group of diseases with a wide spectrum of clinical manifestations, which range from self-limited skin lesions to severe visceral involvement that can lead to death. Leishmaniasis is still a neglected disease, and it is among the priorities of the research program on diseases of poverty of World Health Organization (TDR/WHO). There is no available vaccine and the treatment is based on drugs that cause serious side effects, and are unaffordable in several endemic countries. Metal-based drugs represent a novel antimicrobial and anti-cancer therapeutics arsenal. Peptidase inhibitors/chelating agents such as 1,10-phenanthroline and its substituted derivatives, either the metal-free state or as ligands coordinated to transition metals, interfere with crucial functions of several biological systems. In previous works, our group described that L. braziliensis produced gp63 molecules sensible to 1,10-phenanthroline. Herein, we initially studied the cellular distribution of gp63 in a virulent strain of L. braziliensis by biochemical and immunocytochemical analyses. After that, we reported the inhibitory effects of three 1,10-phenanthroline derivative compounds, 1,10-phenanthroloine-5,6-dione (phendio), [Cu(phendio)2] and [Ag(phendio)2], on both cellular and extracellular metallopeptidase activities produced by L. braziliensis promastigotes as well as their actions on the parasite viability and on the interaction with murine macrophage cells. The gp63 molecules were detected in several parasite compartments, including cytoplasm, membrane lining the cell body and flagellum, and flagellar pocket. The treatment of L. braziliensis promastigotes for 1 hour with 1,10-phenanthroline and its derivatives resulted in a significant inhibition of cell viability and showed an irreversible mechanism of action. These metallopeptidase inhibitors induced apoptosis in L. braziliensis promastigotes as judged by annexin/propidium iodide staining and TUNEL assays ...