In vitro and in vivo antineoplastic activity of a novel bromopyrrole and its potential mechanism of action

AbstractMicrotubules (MTs) are structural units in the cytoskeleton. In brain cells they are responsible for axonal transport, information processing, and signaling mechanisms. Proper function of these processes is critical for healthy brain functions. Alcohol and substance use disorders (AUD/SUDs) affects the function and organization of MTs in the brain, making them a potential neuroimaging marker to study the resulting impairment of overall neurobehavioral and cognitive processes. Our lab reported the first brain-penetrant MT-tracking Positron Emission Tomography (PET) ligand [11C]MPC-6827 and demonstrated its in vivo utility in rodents and non-human primates. To further explore the in vivo imaging potential of [11C]MPC-6827, we need to investigate its mechanism of action. Here, we report preliminary in vitro binding results in SH-SY5Y neuroblastoma cells exposed to ethanol (EtOH) or cocaine in combination with multiple agents that alter MT stability. EtOH and cocaine treatments increased MT stability and decreased free tubulin monomers. Our initial cell-binding assay demonstrated that [11C]MPC-6827 may have high affinity to free/unbound tubulin units. Consistent with this mechanism of action, we observed lower [11C]MPC-6827 uptake in SH-SY5Y cells after EtOH and cocaine treatments (e.g., fewer free tubulin units). We are currently performing in vivo PET imaging and ex vivo biodistribution studies in rodent and nonhuman primate models of AUD and SUDs and Alzheimer's disease.

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Bacteriophage-derived CHAP domain protein, P128, kills Staphylococcus cells by cleaving interpeptide cross-bridge of peptidoglycan

Microbiology ◽

10.1099/mic.0.079111-0 ◽

2014 ◽

Vol 160 (10) ◽

pp. 2157-2169 ◽

Cited By ~ 13

Author(s):

Sudarson Sundarrajan ◽

Junjappa Raghupatil ◽

Aradhana Vipra ◽

Nagalakshmi Narasimhaswamy ◽

Sanjeev Saravanan ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Mechanism Of Action ◽

Catalytic Domain ◽

Antibiotic Sensitivity ◽

High Sensitivity ◽

Common Mechanism ◽

Cross Bridge ◽

Sensitivity Pattern

P128 is an anti-staphylococcal protein consisting of the Staphylococcus aureus phage-K-derived tail-associated muralytic enzyme (TAME) catalytic domain (Lys16) fused with the cell-wall-binding SH3b domain of lysostaphin. In order to understand the mechanism of action and emergence of resistance to P128, we isolated mutants of Staphylococcus spp., including meticillin-resistant Staphylococcus aureus (MRSA), resistant to P128. In addition to P128, the mutants also showed resistance to Lys16, the catalytic domain of P128. The mutants showed loss of fitness as shown by reduced rate of growth in vitro. One of the mutants tested was found to show reduced virulence in animal models of S. aureus septicaemia suggesting loss of fitness in vivo as well. Analysis of the antibiotic sensitivity pattern showed that the mutants derived from MRSA strains had become sensitive to meticillin and other β-lactams. Interestingly, the mutant cells were resistant to the lytic action of phage K, although the phage was able to adsorb to these cells. Sequencing of the femA gene of three P128-resistant mutants showed either a truncation or deletion in femA, suggesting that improper cross-bridge formation in S. aureus could be causing resistance to P128. Using glutathione S-transferase (GST) fusion peptides as substrates it was found that both P128 and Lys16 were capable of cleaving a pentaglycine sequence, suggesting that P128 might be killing S. aureus by cleaving the pentaglycine cross-bridge of peptidoglycan. Moreover, peptides corresponding to the reported cross-bridge of Staphylococcus haemolyticus (GGSGG, AGSGG), which were not cleaved by lysostaphin, were cleaved efficiently by P128. This was also reflected in high sensitivity of S. haemolyticus to P128. This showed that in spite of sharing a common mechanism of action with lysostaphin, P128 has unique properties, which allow it to act on certain lysostaphin-resistant Staphylococcus strains.

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Response of Cisplatin Resistant Skov-3 Cells to [Pt(O,O′-Acac)(γ-Acac)(DMS)] Treatment Revealed by a Metabolomic 1H-NMR Study

Molecules ◽

10.3390/molecules23092301 ◽

2018 ◽

Vol 23 (9) ◽

pp. 2301 ◽

Cited By ~ 12

Author(s):

Federica De Castro ◽

Michele Benedetti ◽

Giovanna Antonaci ◽

Laura Del Coco ◽

Sandra De Pascali ◽

...

Keyword(s):

Ovarian Carcinoma ◽

1H Nmr ◽

Mechanism Of Action ◽

Culture Media ◽

Epithelial Ovarian Carcinoma ◽

Multivariate Statistical ◽

Nmr Study ◽

First Time

The novel [Pt(O,O′-acac)(γ-acac)(DMS)], Ptac2S, Pt(II) complex has recently gained increasing attention as a potential anticancer agent for its pharmacological activity shown in different tumor cell lines, studied both in vitro and in vivo. The mechanism of action of Ptac2S, operating on non-genomic targets, is known to be very different from that of cis-[PtCl2(NH3)2], cisplatin, targeting nucleic acids. In this work, we evaluated the cytotoxicity of Ptac2S on the cisplatin resistant Epithelial Ovarian Carcinoma (EOC), SKOV-3 cells, by the MTT assay. A 1H-NMR metabolomic approach coupled with multivariate statistical analysis was used for the first time for Ptac2S to figure out the biological mechanisms of action of the complex. The metabolic variations of intracellular metabolites and the composition of the corresponding extracellular culture media were compared to those of cisplatin (cells were treated at the IC50 doses of both drugs). The reported comparative metabolomic analysis revealed a very different metabolic profile between Ptac2S and cisplatin treated samples, thus confirming the different mechanism of action of Ptac2S also in the Epithelial Ovarian Carcinoma (EOC), SKOV-3 cells line. In particular, higher levels of pyruvate were observed in Ptac2S treated, with respect to cisplatin treated, cells (in both aqueous and culture media). In addition, a very different lipid expression resulted after the exposure to the two drugs (Ptac2S and cisplatin). These results suggest a possible explanation for the Ptac2S ability to circumvent cisplatin resistance in SKOV-3 cells.

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In vitro and in vivo effects of fumonisins : toxicity and mechanism of action

JSM Mycotoxins ◽

10.2520/myco1975.1994.1 ◽

1994 ◽

Vol 1994 (39) ◽

pp. 1-12 ◽

Cited By ~ 2

Author(s):

K. A. Voss ◽

W. J. CHAMBERLAIN ◽

R. T. RILEY ◽

C. W. BACON ◽

W. P. NORRED

Keyword(s):

Mechanism Of Action ◽

In Vivo Effects

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Comparative in vivo studying of potential antineoplastic properties among of amino-acid derivative glycosides of the indolocarbazole (detailed report)

Russian Journal of Biotherapy ◽

10.17650/1726-9784-2018-17-2-71-77 ◽

2018 ◽

Vol 17 (2) ◽

pp. 71-77

Author(s):

I. S. Golubeva ◽

O. V. Goryunova ◽

N. P. Yavorskaya

Keyword(s):

Amino Acid ◽

Computer Method ◽

Antineoplastic Activity ◽

Amino Acid Derivative ◽

Optimum Dose ◽

Tumor Growth Inhibition ◽

Antineoplastic Effect ◽

Significant Probability

Introduction.The existence of the active metabolite (amino acid) residue in the of an indolocarbazole molecule changes physical-chemical and pro-medicinal properties of aminoacid derivatives glycosides of indolocarbazole. The computer method has earlier foretold low probability of their cytotoxic activity in vitro that was confirmed in the MTT-test on 5 lines of tumor cells. The same computer method predicted significant probability of antineoplastic activity of aminoacid derivatives glycosides of indolocarbazole in vivo that demands the experimental check. Purpose of the study– assessment of aminoacid derivatives glycosides of indolocarbazole as potential antitumor medications.Materials and methods.The research of antineoplastic activity of aminoacid derivatives glycosides of indolocarbazole was performed on mice tumoral models – cervical cancer СС5. Abdominal injections were made to CBA/Lac mice 5 times a day with 24 h interval. Observation of animals was continued till their death. The antineoplastic effect of medicines was estimated according to tumor growth inhibition, increase in life expectancy of experiental mice in comparison with control animals.Results.The optimum dose for this number of compounds, equal to 100 mg/kg is titrated. The antineoplastic activity of aminoacid derivatives glycosides of indolocarbazole on the model СС5 is estimated.Conclusions.On the basis of the obtained data the expanded research of antineoplastic properties of the selected 5 aminoacid derivatives glycosides of indolocarbazole is supposed to perform in vivo.

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Active Substances from Callicarpa nudiflora Exert Anti-Cervicitis Effects and Regulate NLRP3-Associated Inflammation

Molecules ◽

10.3390/molecules26206217 ◽

2021 ◽

Vol 26 (20) ◽

pp. 6217

Author(s):

Tianchi Liu ◽

Ruiqi Wang ◽

Chenpeng Liu ◽

Jiahong Lu ◽

Yitao Wang ◽

...

Keyword(s):

Chinese Medicine ◽

Ethanol Extract ◽

Inflammatory Factor ◽

Potential Mechanism ◽

Active Components ◽

New Agents ◽

Scientific Support ◽

Active Substances

Luohuazizhu suppository is a Traditional Chinese Medicine used in clinic to treat cervicitis, which is prepared from Callicarpa nudiflora Hook. et Arn (C. nudiflora), an herbal Chinese medicine named Luohuazizhu. This study aimed to figure out the active constituents of C. nudiflora and the potential mechanism for its anti-cervicitis effect. The ethanol extract in C. nudiflora (CNE) and the different fractions of CNE extracted by petroleum ether (CNE-p), dichloromethane (CNE-d), and n-butanol (CNE-b) were tested in vivo for their anti-cervicitis effects. Then the isolated compounds from the CNE-p were tested in vitro for their anti-inflammatory activities. The results displayed that CNE-p, CNE-d, and CNE-b exhibited adequate anti-cervicitis effects, with CNE-p showing the highest efficacy. Further experiment demonstrated that CNE-p could significantly inhibit the expression of NLRP3 in vitro. Six diterpenoids obtained from the CNE-p showed the ability to regulate inflammatory factor levels in vitro. Among these compounds, compounds 1 (callicarpic acid A) and 2 (syn-3,4-seco-12S-hydroxy-15,16-epoxy-4(18),8(17),3(16),14(15)-labdatetraen-3-oic acid) were the most effective agents, and they also inhibited the expression level of NLRP3 in vitro. The results confirmed that C. nudiflora has significant anti-cervicitis effects and the diterpenoids were most likely to be its active components. These data provide scientific support for the clinic usage of Luohuazizhu suppository and the development of new agents in treating cervicitis.

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Skrining Mekanisme Kerja Daun Malaka (Phyllanthus emblica L.) Sebagai Antidiabetes

Talenta Conference Series Tropical Medicine (TM) ◽

10.32734/tm.v1i3.271 ◽

2018 ◽

Vol 1 (3) ◽

pp. 106-110

Author(s):

Novi Irwan Fauzi ◽

Seno Aulia Ardiansyah ◽

Saeful Hidayat

Keyword(s):

Mechanism Of Action ◽

Inhibitory Activity ◽

Leaf Extract ◽

Test Method ◽

Diabetic Rat ◽

Phyllanthus Emblica ◽

Insulin Sensitizer ◽

Water Fraction

Daun malaka (Phyllanthus emblica L.) mempunyai potensi digunakan sebagai alternatif obat antidiabetes. Daun malaka menunjukkan efek hipoglikemia pada tikus yang diinduksi aloksan. Namun, mekanisme kerjanya belum diketahui pasti. Penelitian ini dilakukan dalam rangka skrining mekanisme kerja daun malaka sebagai antidiabetes. Skrining mekanisme kerja dilakukan terhadap fraksi air daun malaka melalui uji aktivitas inhibisi enzim α-glukosidase serta α-amilase secara in vitro dan pengujian aktivitas insulin-sensitizer terhadap ekstrak daun malaka dengan metode tes toleransi insulin secara in vivo. Fraksi air daun malaka menunjukkan aktivitas inhibisi terhadap enzim α-glukosidase serta α-amilase dengan nilai IC50 (Inhibitor Concentration 50) pada kedua enzim tersebut berturut-turut adalah 0,87% dan 8,64% b/v. Pada uji aktivitas insulin sensitizer, pemberian ekstrak daun malaka dapat meningkatkan sensitivitas insulin pada tikus diabet dengan kondisi resistensi insulin. Nilai KTTI pada kelompok tikus diabet yang diberi ekstrak daun malaka dosis 100 dan 500 mg/kgbb tikus (74,89 dan 75,57) lebih tinggi dibandingkan kelompok tikus diabet (38,41) dan kadar glukosa darah yang lebih rendah selama interval waktu pengukuran. Daun malaka telah diketahui mampu meningkatkan sekresi insulin dan pada penelitian ini menunjukkan aktivitas inhibisi enzim α-glukosidase serta α-amilase secara in vitro dan menunjukkan aktivitas insulinsensitizer pada tikus diabet dengan kondisi resistensi insulin. Malaka leaf (Phyllanthus emblica L.) has the potential to be used as an alternative antidiabetic drug. Malacca leaves showed hypoglycemia effect in rat induced by alloxan. However, the mechanism of action is not yet known. This study was conducted to evaluate the mechanism of action of Malaka leaves as antidiabetic. Screening of the mechanism of action was carried out on the water fraction of Malaka leaf byinhibitory activity examination on α-glucosidase and α-amylase by in vitro studyand Evaluation of insulin-sensitizer activity of Maaka leaf leaf extract was conducted by invivo insulin tolerance test method. Malaka leaf water fraction showed inhibitory activity against the α-glucosidase and α-amylase with IC50 values (Inhibitory Concentration 50) of0.87% and 8.64% b / v on both enzyme, respectively. The evaluation of insulin sensitizer revelead that administration ofMalaka leaf extract can increase insulin sensitivity in diabetic rat with insulin resistance.KTTI values in diabetic rats given malaka extract at the dose of 100 and 500 mg / kg BW (74.89 and 75.57) were higher than diabetics rat (38.41) and the extract also decrease blood glucose levels during measurement time intervals . Malaka leafhas been known to increase insulin secretion and the study showedthe inhibitory activity on α-glucosidase and α-amylase by in vitro study and showed insulinsensitizer activity in diabetic rat with insulin resistance.

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Structure-based mechanism of action of a viral poly(ADP-ribose) polymerase 1-interacting protein facilitating virus replication

IUCrJ ◽

10.1107/s2052252518013854 ◽

2018 ◽

Vol 5 (6) ◽

pp. 866-879 ◽

Cited By ~ 1

Author(s):

Woo-Chang Chung ◽

Junsoo Kim ◽

Byung Chul Kim ◽

Hye-Ri Kang ◽

JongHyeon Son ◽

...

Keyword(s):

Mechanism Of Action ◽

Molecular Mechanisms ◽

Lytic Replication ◽

Transcription Activator ◽

Interacting Protein ◽

Murine Gammaherpesvirus ◽

Unit Structure ◽

Parp 1

Poly(ADP-ribose) polymerase 1 (PARP-1), an enzyme that modifies nuclear proteins by poly(ADP-ribosyl)ation, regulates various cellular activities and restricts the lytic replication of oncogenic gammaherpesviruses by inhibiting the function of replication and transcription activator (RTA), a key switch molecule of the viral life cycle. A viral PARP-1-interacting protein (vPIP) encoded by murine gammaherpesvirus 68 (MHV-68) orf49 facilitates lytic replication by disrupting interactions between PARP-1 and RTA. Here, the structure of MHV-68 vPIP was determined at 2.2 Å resolution. The structure consists of 12 α-helices with characteristic N-terminal β-strands (Nβ) and forms a V-shaped-twist dimer in the asymmetric unit. Structure-based mutagenesis revealed that Nβ and the α1 helix (residues 2–26) are essential for the nuclear localization and function of vPIP; three residues were then identified (Phe5, Ser12 and Thr16) that were critical for the function of vPIP and its interaction with PARP-1. A recombinant MHV-68 harboring mutations of these three residues showed severely attenuated viral replication both in vitro and in vivo. Moreover, ORF49 of Kaposi's sarcoma-associated herpesvirus also directly interacted with PARP-1, indicating a conserved mechanism of action of vPIPs. The results elucidate the novel molecular mechanisms by which oncogenic gammaherpesviruses overcome repression by PARP-1 using vPIPs.

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Venetoclax enhances T cell-mediated anti-leukemic activity by increasing ROS production

Blood ◽

10.1182/blood.2020009081 ◽

2021 ◽

Author(s):

JongBok Lee ◽

Dilshad H. Khan ◽

Rose Hurren ◽

Mingjing Xu ◽

Yoosu Na ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Mechanism Of Action ◽

Adoptive Cell Therapy ◽

Complete Response ◽

Ros Generation ◽

Activated T Cells ◽

Treatment Naïve

Venetoclax, a Bcl-2 inhibitor, in combination with the hypomethylating agent, Azacytidine, achieves complete response with or without count recovery in approximately 70% of treatment-naïve elderly patients unfit for conventional intensive chemotherapy. However, the mechanism of action of this drug combination is not fully understood. We discovered that Venetoclax directly activated T cells to increase their cytotoxicity against AML in vitro and in vivo. Venetoclax enhanced T cell effector function by increasing ROS generation through inhibition of respiratory chain supercomplexes formation. In addition, Azacytidine induced a viral-mimicry response in AML cells by activating the STING/cGAS pathway, thereby rendering the AML cells more susceptible to T-cell mediated cytotoxicity. Similar findings were seen in patients treated with Venetoclax as this treatment increased ROS generation and activated T cells. Collectively, this study demonstrates a new immune mediated mechanism of action for Venetoclax and Azacytidine in the treatment of AML and highlights a potential combination of Venetoclax and adoptive cell therapy for patients with AML.

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