Novel inexpensive ‘turn-on’ fluorescent biosensor for the sensitive detection of DNA damage induced by epirubicin

Analytical-Quality-by-Design Fluoroprobes for Quantitation of Entecavir and Penciclovir in Spiked Human Plasma and Content Uniformity Testing: Insights of DNA Mismatching, Three-Colors Assessment and Sustainability Profiling

Entecavir and penciclovir are nucleoside-analog antiviral drugs structurally related to guanine that act by inhibiting the active viral replication process. Through this study, the quantitation of both drugs was carried out using two fluorescent probes, referred to as fluoroprobes. The first type was prepared by the addition of surfactants such as Tween 80 and sodium dodecyl sulfate (micelle-enhanced fluoroprobes), while the second type includes the formation of a tertiary complex of drug-terbium-DNA (Tb-DNA fluoroprobes). The preparation of the fluoroprobes was optimized using analytical quality by design (AQbD) via I-optimal design. A positive effect of the selected antiviral drugs on DNA mismatching was observed. The analytical procedures were validated according to ICH guidelines with a linearity range of 2.0-40.0 μM and 25.0-300.0 nM for micelle-enhanced and Tb-DNA fluoroprobes, respectively. The analytical procedures were evaluated in compliance with the three-color (GBW) assessments: greenness (using AGREE and ComplexGAPI metrics), blueness (using the BAGI tool), and whiteness (using the RGB algorithm). The sustainability profiles were established using the efficient-valid-green (EVG) framework. Both types of fluoroprobes were successfully applied to quantify entecavir and penciclovir in content uniformity testing and spiked human plasma as a simpler and cheaper alternative to hyphenated analytical techniques.

Structure optimization and molecular dynamics studies of new tumor-selective s-triazines targeting DNA and MMP-10/13 for halting colorectal and secondary liver cancers

A series of triazole-tethered triazines bearing pharmacophoric features of DNA-targeting agents and non-hydroxamate MMPs inhibitors were synthesized and screened against HCT-116, Caco-2 cells, and normal colonocytes by MTT assay. 7a and 7g surpassed doxorubicin against HCT-116 cells regarding potency (IC50 = 0.87 and 1.41 nM) and safety (SI = 181.93 and 54.41). 7g was potent against liver cancer (HepG-2; IC50 = 65.08 nM), the main metastatic site of CRC with correlation to MMP-13 expression. Both derivatives induced DNA damage at 2.67 and 1.87 nM, disrupted HCT-116 cell cycle and triggered apoptosis by 33.17% compared to doxorubicin (DNA damage at 0.76 nM and 40.21% apoptosis induction). 7g surpassed NNGH against MMP-10 (IC50 = 0.205 μM) and MMP-13 (IC50 = 0.275 μM) and downregulated HCT-116 VEGF related to CRC progression by 38%. Docking and MDs simulated ligands-receptors binding modes and highlighted SAR. Their ADMET profiles, drug-likeness and possible off-targets were computationally predicted.

Exploiting spirooxindoles for dual DNA targeting/CDK2 inhibition and simultaneous mitigation of oxidative stress towards selective NSCLC therapy; synthesis, evaluation, and molecular modelling studies

The unique structure of spirooxindoles and their ability to feature various pharmacophoric motifs render them privileged scaffolds for tailoring new multitarget anticancer agents. Herein, a stereoselective multicomponent reaction was utilized to generate a small combinatorial library of pyrazole-tethered spirooxindoles targeting DNA and CDK2 with free radical scavenging potential as an extra bonus. The designed spirooxindoles were directed to combat NSCLC via inducing apoptosis and alleviating oxidative stress. The series' absolute configuration was assigned by X-ray diffraction analysis. Cytotoxicity screening of the developed spirooxindoles against NSCLC A549 and H460 cells compared to normal lung fibroblasts Wi-38 revealed the sensitivity of A549 cells to the compounds and raised 6e and 6h as the study hits (IC50 ∼ 0.09 μM and SI > 3). They damaged DNA at 24.6 and 35.3 nM, and surpassed roscovitine as CDK2 inhibitors (IC50 = 75.6 and 80.2 nM). Docking and MDs simulations postulated their receptors binding modes. The most potent derivative, 6e, induced A549 apoptosis by 40.85% arresting cell cycle at G2/M phase, and exhibited antioxidant activity in a dose-dependent manner compared to Trolox as indicated by DPPH scavenging assay. Finally, in silico ADMET analysis predicted the drug-likeness properties of 6e.

Sensitive "release-on-demand" fluorescent genosensors for probing DNA damage induced by commonly used cardiovascular drugs: Comparative study

Cardiovascular drugs (CVDs) are agents working on the heart and the vascular system to treat many cardiovascular disorders. Such disorders represent the leading cause for morbidity and mortality worldwide. The treatment regimen includes different administered drugs on chronic basis. The cumulative drugs in human body coincides with exposure to electromagnetic radiations from different sources leading to drug-radiation interaction that may lead to drug photosensitization. Such photosensitization may lead to mutagenesis, cancer, and cell death due to molecular damage to DNA. This work involves the application of two bioluminescent genosensors; Terbium chloride and EvaGreen are utilized to investigate potential DNA damage caused by frequently used CVDs following UVA irradiation. A variety of CVDs are investigated. Ten drugs; Amiloride, Atorvastatin, Captopril, Enalapril, Felodipine, Hydrochlorothiazide, Indapamide, Losartan, Triamterene and Valsartan are studied. The study's findings showed that such drugs induced DNA damage following UVA irradiation. The induced DNA damage altered the fluorescence of terbium chloride and EvaGreen genosensors, proportionally. The results are confirmed by viscosity measurements reflecting the possible intercalation of CVDs with DNA. Also, the work is applied on calf thymus DNA to mimic the actual biological variability. The demonstrated bioluminescent genosensors provide automatic, simple and low-cost methods for assessing DNA-drug interactions.

Triggering Breast Cancer Apoptosis via Cyclin-Dependent Kinase Inhibition and DNA Damage by Novel Pyrimidinone and 1,2,4-Triazolo[4,3-a]pyrimidinone Derivatives

Combinations of apoptotic inducers are common clinical practice in breast cancer. However, their efficacy is limited by the heterogeneous pharmacokinetic profiles. An advantageous alternative is merging their molecular entities in hybrid multitargeted scaffolds exhibiting synergistic activities and uniform distribution. Herein, we report apoptotic inducers simultaneously targeting DNA and CDK-2 (cyclin-dependent kinase-2) inspired by studies revealing that CDK-2 inhibition sensitizes breast cancer to DNA-damaging agents. Accordingly, rationally substituted pyrimidines and triazolopyrimidines were synthesized and assayed by MTT against MCF-7, MDA-MB231, and Wi-38 cells compared to doxorubicin. The N-(4-amino-2-((2-hydrazinyl-2-oxoethyl)thio)-6-oxo-1,6-dihydropyrimidin-5-yl)acetamide 5 and its p-nitrophenylhydrazone 8 were the study hits against MCF-7 (IC50 = 0.050 and 0.146 μM) and MDA-MB231 (IC50 = 0.826 and 0.583 μM), induced DNA damage at 10.64 and 30.03 nM, and inhibited CDK-2 (IC50 = 0.172 and 0.189 μM). 5 induced MCF-7 apoptosis by 46.75% and disrupted cell cycle during S phase. Docking and MD simulations postulated their stable key interactions.

Identification of new 5-(2,6-dichlorophenyl)-3-oxo-2,3-dihydro-5H-thiazolo[3,2-a]pyrimidine-7-carboxylic acids as p38α MAPK inhibitors: Design, synthesis, antitumor evaluation, molecular docking and in silico studies

In pursuit of discovering novel scaffolds that demonstrate potential inhibitory activity against p38α MAPK and possess strong antitumor effects, we herein report the design and synthesis of new series of 17 final target 5-(2,6-dichlorophenyl)-3-oxo-2,3-dihydro-5H-thiazolo[3,2-a]pyrimidine-7-carboxylic acids (4-20). Chemical characterization of the compounds was performed using FT-IR, NMR, elemental analyses and mass spectra of some representative examples. With many compounds showing potential inhibitory activity against p38α MAPK, two derivatives, 8 and 9, demonstrated the highest activity (>70 % inhibition) among the series. Derivative 9 displayed IC50 value nearly 2.5 folds more potent than 8. As anticipated, they both showed explicit interactions inside the kinase active site with the key binding amino acid residues. Screening both compounds for cytotoxic effects, they exhibited strong antitumor activities against lung (A549), breast (MCF-7 and MDA MB-231), colon (HCT-116) and liver (Hep-G2) cancers more potent than reference 5-FU. Their noticeable strong antitumor activity pointed out to the possibility of an augmented DNA binding mechanism of antitumor action besides their kinase inhibition. Both 8 and 9 exhibited strong ctDNA damaging effects in nanomolar range. Further mechanistic antitumor studies revealed ability of compounds 8 and 9 to arrest cell cycle in MCF-7 cells at S phase, while in HCT-116 treated cells at G0-G1 and G2/M phases. They also displayed apoptotic induction effects in both MCF-7 and HCT-116 with total cell deaths more than control untreated cells in reference to 5-FU. Finally, the compounds were tested for their anti-migratory potential utilizing wound healing assay. They induced a significant decrease in wound closure percentage after 24 h treatment in the examined cancer cells when compared to untreated control MCF-7 and HCT-116 cells better than 5-FU. In silico computation of physicochemical parameters revealed the drug-like properties of 8 and 9 with no violation to Lipinski's rule of five as well as their tolerable ADMET parameters, thus suggesting their utilization as potential future drug leads amenable for further optimization and development.

Analytical Methodologies for the Estimation of Oxazolidinone Antibiotics as Key Members of anti-MRSA Arsenal: A Decade in Review

Gram-positive bacterial infections are among the most serious diseases related with high mortality rates and huge healthcare costs especially with the rise of antibiotic-resistant strains that limits treatment options. Thus, development of new antibiotics combating these multi-drug resistant bacteria is crucial. Oxazolidinone antibiotics are the only totally synthetic group of antibiotics that showed activity against multi-drug resistant Gram positive bacteria including MRSA because of their unique mechanism of action in targeting protein synthesis. This group include approved marketed members (tedizolid, linezolid and contezolid) or those under development (delpazlolid, radezolid and sutezolid). Due to the significant impact of this class, larger number of analytical methods were required to meet the needs of both clinical and industrial studies. Analyzing these drugs either alone or with other antimicrobial agents commonly used in ICU, in the presence of pharmaceutical or endogenous biological interferences, or in the presence of matrix impurities as metabolites and degradation products poses a big analytical challenge. This review highlights current analytical approaches published in the last decade (2012-2022) that dealt with the determination of these drugs in different matrices and discusses their advantages and disadvantages. Various techniques have been described for their determination including chromatographic, spectroscopic, capillary electrophoretic and electroanalytical methods. The review comprises six sections (one for each drug) with their related tables that depict critical figures of merit and some experimental conditions for the reviewed methods. Furthermore, future perspectives about the analytical methodologies that can be developed in the near future for determination of these drugs are suggested.

Sensitive MALDI-TOF MS and 'turn-on' fluorescent genosensor for the determination of DNA damage induced by CNS acting drugs

The genotoxic and carcinogenic adverse effects of various drugs should be considered for assessing drug benefit/risk ratio. On that account, the scope of this study is to examine the kinetics of DNA damage triggered by three CNS acting drugs; carbamazepine, quetiapine and desvenlafaxine. Two precise, simple and green approaches were proposed for probing drug induced DNA impairment; MALDI-TOF MS and terbium (Tb³⁺) fluorescent genosensor. The results revealed that all the studied drugs induced DNA damage manifested by the MALDI-TOF MS analysis as a significant disappearance of the DNA molecular ion peak with the appearance of other peaks at smaller m/z indicating the formation of DNA strand breaks. Moreover, significant enhancement of Tb³⁺ fluorescence occurred, proportional to the amount of DNA damage, upon incubation of each drug with dsDNA. Furthermore, the DNA damage mechanism is examined. The proposed Tb³⁺ fluorescent genosensor showed superior selectivity and sensitivity and is significantly simpler and less expensive than other methods reported for the detection of DNA damage. Moreover, the DNA damaging potency of these drugs was studied using calf thymus DNA in order to clarify the potential safety hazards associated with the studied drugs on natural DNA.

Novel genosensor for probing DNA mismatches and UV-induced DNA damage: Sequence-specific recognition

Human genome is continuously susceptible to changes that may lead to undesirable mutations causing various diseases and cancer. Vast majority of techniques has investigated the discrimination between base-pair mismatched nucleic acid, but many of these techniques are time-consuming, complex, expensive, and limited to the detection of specific type of dsDNA mismatches. In this study, we introduce a simple mix-and-read assay for the sensitive and cost-effective analysis of DNA base mismatches and UV-induced DNA damage using Hoechst genosensor dye (H258). This dye is a minor groove binder that undergoes a drastic conformational change upon binding with mismatch DNA. The difference in binding affinity between perfectly matched and mismatched DNA was studied for sequences at different base mismatch locations and finally, extended for the detection of dsDNA damage by UVC radiation in calf thymus DNA. In addition, a comparative DNA damage kinetic study was performed using H258 (minor groove binder) and EvaGreen (intercalating) dye to get insight on assay selectivity and sensitivity with dye binding mechanism. The result shows good reproducibility making H258 genosensor a cheaper alternative for DNA mismatch and damage studies with possibility of extension for in-vitro detection of hot spots of DNA mutations.