scholarly journals New Investigations with Lupane Type A-Ring Azepane Triterpenoids for Antimycobacterial Drug Candidate Design

2021 ◽  
Vol 22 (22) ◽  
pp. 12542
Author(s):  
Oxana Kazakova ◽  
Roxana Racoviceanu ◽  
Anastasiya Petrova ◽  
Marius Mioc ◽  
Adrian Militaru ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Wild Strain ◽  
Type A ◽  
Antitubercular Activity ◽  
Mycobacterium Abscessus ◽  
Cell Permeability ◽  
Drug Candidate ◽  
Highly Active ◽  
Similarity Algorithm ◽  
Low Cytotoxicity

Twenty lupane type A-ring azepano-triterpenoids were synthesized from betulin and its related derivatives and their antitubercular activity against Mycobacterium tuberculosis, mono-resistant MTB strains, and nontuberculous strains Mycobacterium abscessus and Mycobacterium avium were investigated in the framework of AToMIc (Anti-mycobacterial Target or Mechanism Identification Contract) realized by the Division of Microbiology and Infectious Diseases, NIAID, National Institute of Health. Of all the tested triterpenoids, 17 compounds showed antitubercular activity and 6 compounds were highly active on the H37Rv wild strain (with MIC 0.5 µM for compound 7), out of which 4 derivatives also emerged as highly active compounds on the three mono-resistant MTB strains. Molecular docking corroborated with a machine learning drug-drug similarity algorithm revealed that azepano-triterpenoids have a rifampicin-like antitubercular activity, with compound 7 scoring the highest as a potential M. tuberculosis RNAP potential inhibitor. FIC testing demonstrated an additive effect of compound 7 when combined with rifampin, isoniazid and ethambutol. Most compounds were highly active against M. avium with compound 14 recording the same MIC value as the control rifampicin (0.0625 µM). The antitubercular ex vivo effectiveness of the tested compounds on THP-1 infected macrophages is correlated with their increased cell permeability. The tested triterpenoids also exhibit low cytotoxicity and do not induce antibacterial resistance in MTB strains.

scholarly journals Structure-Based Drug Design and Characterization of Sulfonyl-Piperazine Benzothiazinone Inhibitors of DprE1 from Mycobacterium tuberculosis

2018 ◽  
Vol 62 (10) ◽  
Author(s):  
Jérémie Piton ◽  
Anthony Vocat ◽  
Andréanne Lupien ◽  
Caroline S. Foo ◽  
Olga Riabova ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Drug Design ◽  
Antitubercular Activity ◽  
Cysteine Residue ◽  
Drug Candidate ◽  
Structure Based Drug Design ◽  
Content Type ◽  
Active Site Cysteine ◽  
Covalent Adducts

ABSTRACT Macozinone (MCZ) is a tuberculosis (TB) drug candidate that specifically targets the essential flavoenzyme DprE1, thereby blocking synthesis of the cell wall precursor decaprenyl phosphoarabinose (DPA) and provoking lysis of Mycobacterium tuberculosis. As part of the MCZ backup program, we exploited structure-guided drug design to produce a new series of sulfone-containing derivatives, 2-sulfonylpiperazin 8-nitro 6-trifluoromethyl 1,3-benzothiazin-4-one, or sPBTZ. These compounds are less active than MCZ but have a better solubility profile, and some derivatives display enhanced stability in microsomal assays. DprE1 was efficiently inhibited by sPBTZ, and covalent adducts with the active-site cysteine residue (C387) were formed. However, despite the H-bonding potential of the sulfone group, no additional bonds were seen in the crystal structure of the sPBTZ-DprE1 complex with compound 11326127 compared to MCZ. Compound 11626091, the most advanced sPBTZ, displayed good antitubercular activity in the murine model of chronic TB but was less effective than MCZ. Nonetheless, further testing of this MCZ backup compound is warranted as part of combination treatment with other TB drugs.

scholarly journals Newly developed dual topoisomerase inhibitor P8-D6 is highly active in ovarian cancer

2021 ◽  
Vol 13 ◽  
pp. 175883592110598
Author(s):  
Inken Flörkemeier ◽  
Tamara N. Steinhauer ◽  
Nina Hedemann ◽  
Magnus Ölander ◽  
Per Artursson ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Topoisomerase I ◽  
Ex Vivo ◽  
Chemotherapy Resistance ◽  
Membrane Integrity ◽  
Three Dimensional ◽  
New Drugs ◽  
Highly Active ◽  
Gynaecologic Neoplasms

Background: Ovarian cancer (OvCa) constitutes a rare and highly aggressive malignancy and is one of the most lethal of all gynaecologic neoplasms. Due to chemotherapy resistance and treatment limitations because of side effects, OvCa is still not sufficiently treatable. Hence, new drugs for OvCa therapy such as P8-D6 with promising antitumour properties have a high clinical need. The benzo[ c]phenanthridine P8-D6 is an effective inductor of apoptosis by acting as a dual topoisomerase I/II inhibitor. Methods: In the present study, the effectiveness of P8-D6 on OvCa was investigated in vitro. In various OvCa cell lines and ex vivo primary cells, the apoptosis induction compared with standard therapeutic agents was determined in two-dimensional monolayers. Expanded by three-dimensional and co-culture, the P8-D6 treated cells were examined for changes in cytotoxicity, apoptosis rate and membrane integrity via scanning electron microscopy (SEM). Likewise, the effects of P8-D6 on non-cancer human ovarian surface epithelial cells and primary human hepatocytes were determined. Results: This study shows a significant P8-D6-induced increase in apoptosis and cytotoxicity in OvCa cells which surpasses the efficacy of well-established drugs like cisplatin or the topoisomerase inhibitors etoposide and topotecan. Non-cancer cells were affected only slightly by P8-D6. Moreover, no hepatotoxic effect in in vitro studies was detected. Conclusion: P8-D6 is a strong and rapid inductor of apoptosis and might be a novel treatment option for OvCa therapy.

scholarly journals Honokiol and Magnolol: Insights into Their Antidermatophytic Effects

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2522
Author(s):  
Adriana Trifan ◽  
Andra-Cristina Bostănaru ◽  
Simon Vlad Luca ◽  
Veronika Temml ◽  
Muhammad Akram ◽  
...  
Keyword(s):  
Negative Impact ◽  
Ex Vivo ◽  
Health Concern ◽  
Ergosterol Biosynthesis ◽  
Human Neutrophils ◽  
Traditional Use ◽  
Promising Alternative ◽  
Highly Active ◽  
Tnf Α ◽  
Significant Public Health

Dermatophyte infections represent a significant public health concern, with an alarming negative impact caused by unsuccessful therapeutic regimens. Natural products have been highlighted as a promising alternative, due to their long-standing traditional use and increasing scientific recognition. In this study, honokiol and magnolol, the main bioactives from Magnolia spp. bark, were investigated for their antidermatophytic activity. The antifungal screening was performed using dermatophyte standard strains and clinical isolates. The minimal inhibitory concentration (MIC) and the minimal fungicidal concentration (MFC) were determined in accordance with EUCAST-AFST guidelines, with minor modifications. The effects on ergosterol biosynthesis were assessed in Trichophyton rubrum cells by HPLC-DAD. Putative interactions with terbinafine against T. rubrum were evaluated by the checkerboard method. Their impact on cells’ viability and pro-inflammatory cytokines (IL-1β, IL-8 and TNF-α) was shown using an ex vivo human neutrophils model. Honokiol and magnolol were highly active against tested dermatophytes, with MIC and MFC values of 8 and 16 mg/L, respectively. The mechanism of action involved the inhibition of ergosterol biosynthesis, with accumulation of squalene in T. rubrum cells. Synergy was assessed for binary mixtures of magnolol with terbinafine (FICI = 0.50), while honokiol-terbinafine combinations displayed only additive effects (FICI = 0.56). In addition, magnolol displayed inhibitory effects towards IL-1β, IL-8 and TNF-α released from lipopolysaccharide (LPS)-stimulated human neutrophils, while honokiol only decreased IL-1β secretion, compared to the untreated control. Overall, honokiol and magnolol acted as fungicidal agents against dermatophytes, with impairment of ergosterol biosynthesis.

scholarly journals Alternative to Animal Use for Detecting Biologically Active Staphylococcal Enterotoxin Type A

Toxins ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 540 ◽  
Author(s):  
Reuven Rasooly ◽  
Paula Do ◽  
Xiaohua He ◽  
Bradley Hernlem
Keyword(s):  
Ex Vivo ◽  
Interleukin 2 ◽  
Type A ◽  
Food Products ◽  
Biologically Active ◽  
Quantitative Detection ◽  
Animal Testing ◽  
Chemical Safety ◽  
Live Animal ◽  
Vitro Assay

Staphylococcal enterotoxins (SEs) are a food safety concern. Existing methods for biologically active SE detection rely on the emetic response in live kittens or monkeys. This method suffers from low sensitivity, poor reproducibility, and causes ethical concerns regarding the use of experimental animals. The Lautenberg Chemical Safety Act encourages the development and adoption of alternatives to testing on animals for chemical toxicity methodologies. In this study, we utilized the superantigenic effect of SE type A (SEA) and used an ex vivo bioassay as an alternative to live animal testing. We found that interleukin-2 (IL-2) secreted by splenocyte can be utilized for quantifiable detection of SEA in food products. To avoid food matrix interference and attenuation of signal, we separated SEA from spiked food products by employing immunomagnetic beads that were coated with an anti-SEA antibody. This ex vivo method has achieved the detection of 1 ng mL−1 of SEA, which is 107 times more sensitive than the existing live animal testing methods. However, this ex vivo bioassay requires sacrificing of mice. To overcome this limitation, we established a cell based in vitro assay using CCRF-CEM, a human CD4+ T-cell line, for the quantitative detection of SEA. Incubation of SEA with CCRF-CEM human T-cells and Raji cells led to quantifiable and dose dependent secretion of IL-2. This novel cell-based assay is highly specific to biologically active SEA, compared with the related SE toxin subtypes B, D, and E or heat inactivated SEA, which produce no secretion of IL-2. This is the first demonstration of an alternative assay that completely eliminates the use of animals for quantitative detection of active SEA.

scholarly journals Etamycin as a Novel Mycobacterium abscessus Inhibitor

2020 ◽  
Vol 21 (18) ◽  
pp. 6908
Author(s):  
Bui Thi Bich Hanh ◽  
Tae Ho Kim ◽  
June-Woo Park ◽  
Da-Gyum Lee ◽  
Jae-Sung Kim ◽  
...  
Keyword(s):  
Wild Type Strain ◽  
Standard Of Care ◽  
Mycobacterium Abscessus ◽  
Drug Candidate ◽  
Infection Model ◽  
Excellent Activity ◽  
Further Development ◽  
Clinical Drug

The increase in drug-resistant Mycobacterium abscessus, which has become resistant to existing standard-of-care agents, is a major concern, and new antibacterial agents are strongly needed. In this study, we introduced etamycin that showed an excellent activity against M. abscessus. We found that etamycin significantly inhibited the growth of M. abscessus wild-type strain, three subspecies, and clinical isolates in vitro and inhibited the growth of M. abscessus that resides in macrophages without cytotoxicity. Furthermore, the in vivo efficacy of etamycin in the zebrafish (Danio rerio) infection model was greater than that of clarithromycin, which is recommended as the core agent for treating M. abscessus infections. Thus, we concluded that etamycin is a potential anti-M. abscessus candidate for further development as a clinical drug candidate.

scholarly journals Evaluation of Ceftaroline-Avibactam Activity in vitro and ex vivo Against Mycobacterium abscessus Complex

2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S675-S675 ◽  
Author(s):  
Ruchi Pandey ◽  
Liang Chen ◽  
Elena Shashkina ◽  
Claudia Manca ◽  
Robert A Bonomo ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Mycobacterium Abscessus ◽  
Mycobacterium Abscessus Complex

scholarly journals Synthesis and In Vitro Antibacterial Activity of Quaternized 10-Methoxycanthin-6-one Derivatives

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1553 ◽  
Author(s):  
Na Li ◽  
Dan Liu ◽  
Jiang-Kun Dai ◽  
Jin-Yi Wang ◽  
Jun-Ru Wang
Keyword(s):  
Antibacterial Activity ◽  
Seed Germination ◽  
Pathogenic Bacteria ◽  
Dilution Method ◽  
Highly Active ◽  
Structure Activity ◽  
In Vitro Antibacterial Activity ◽  
Potential Activity ◽  
Low Cytotoxicity

Background: Based on our previous work, we found that 10-methoxycanthin-6-one displayed potential antibacterial activity and quaternization was an available method for increasing the antibacterial activity. Here, we explored the antibacterial activity of quaternized 10-methoxy canthin-6-one derivatives. Methods and Results: Twenty-two new 3-N-benzylated 10-methoxy canthin-6-ones were designed and synthesized through quaternization reaction. The in vitro antibacterial activity against three bacteria was evaluated by the double dilution method. Moreover, the structure–activity relationships (SARs) were carefully summarized in order to guide the development of antibacterial canthin-6-one agents. Two highly active compounds (6p and 6t) displayed 8-fold superiority (MIC = 3.91 µg/mL) against agricultural pathogenic bacteria R. solanacearum and P. syringae compared to agrochemical streptomycin sulfate, and showed potential activity against B. cereus. Moreover, these two compounds exhibited good “drug-like” properties, low cytotoxicity, and no inhibition on seed germination. Conclusions: This work provides two new effective quaternized canthin-6-one derivatives as candidate bactericide, promoting the development of natural-sourced bactericides and preservatives.

scholarly journals Efflux Attenuates the Antibacterial Activity of Q203 in Mycobacterium tuberculosis

2017 ◽  
Vol 61 (7) ◽  
Author(s):  
Jichan Jang ◽  
Ryangyeo Kim ◽  
Minjeong Woo ◽  
Jinsun Jeong ◽  
Da Eun Park ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Efflux Pump ◽  
Ex Vivo ◽  
Drug Candidate ◽  
Content Type ◽  
Tb Treatment ◽  
Pump Activity ◽  
Efflux Pump Inhibitors ◽  
Combinatorial Strategy

ABSTRACT New and improved treatments for tuberculosis (TB) are urgently needed. Recently, it has been demonstrated that verapamil, an efflux inhibitor, can reduce bacterial drug tolerance caused by efflux pump activity when administered in combination with available antituberculosis agents. The aim of this study was to evaluate the effectiveness of verapamil in combination with the antituberculosis drug candidate Q203, which has recently been developed and is currently under clinical trials as a potential antituberculosis agent. We evaluated changes in Q203 activity in the presence and absence of verapamil in vitro using the resazurin microplate assay and ex vivo using a microscopy-based phenotypic assay for the quantification of intracellular replicating mycobacteria. Verapamil increased the potency of Q203 against Mycobacterium tuberculosis both in vitro and ex vivo, indicating that efflux pumps are associated with the activity of Q203. Other efflux pump inhibitors also displayed an increase in Q203 potency, strengthening this hypothesis. Therefore, the combination of verapamil and Q203 may be a promising combinatorial strategy for anti-TB treatment to accelerate the elimination of M. tuberculosis.

scholarly journals Nef-Mediated Enhancement of Virion Infectivity and Stimulation of Viral Replication Are Fundamental Properties of Primate Lentiviruses

2007 ◽  
Vol 81 (24) ◽  
pp. 13852-13864 ◽  
Author(s):  
Jan Münch ◽  
Devi Rajan ◽  
Michael Schindler ◽  
Anke Specht ◽  
Elke Rücker ◽  
...  
Keyword(s):  
Viral Replication ◽  
Ex Vivo ◽  
Cell Receptor ◽  
Human Cells ◽  
Fundamental Properties ◽  
Highly Active ◽  
Immunodeficiency Virus ◽  
Primate Lentiviruses ◽  
Hiv 1

ABSTRACT Nef is a multifunctional accessory protein of primate lentiviruses. Recently, it has been shown that the ability of Nef to downmodulate CD4, CD28, and class I major histocompatibility complex is highly conserved between most or all primate lentiviruses, whereas Nef-mediated downregulation of T-cell receptor-CD3 was lost in the lineage that gave rise to human immunodeficiency virus type 1 (HIV-1). Whether or not other Nef activities are preserved between different groups of primate lentiviruses remained to be determined. Here, we show that nef genes from a large variety of HIVs and simian immunodeficiency viruses (SIVs) enhance virion infectivity and stimulate viral replication in human cells and/or in ex vivo infected human lymphoid tissue (HLT). Notably, nef alleles from unpassaged SIVcpz and SIVsmm enhanced viral infectivity, replication, and cytopathicity in cell culture and in ex vivo infected HLT as efficiently as those from HIV-1 and HIV-2, their human counterparts. Furthermore, nef genes from several highly divergent SIVs that have not been found in humans were also highly active in human cells and/or tissues. Thus, most primate lentiviral Nefs enhance virion infectivity and stimulate viral replication. Moreover, our data show that SIVcpz and SIVsmm Nefs do not require adaptive changes to perform these functions in human cells or tissues and support the idea that nef alleles from other primate lentiviruses would also be capable of promoting efficient virus spread in humans.

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