Sensitive spectrofluorimetric and mass spectroscopic methods for the determination of nucleic acid damage induced by photosensitized anti-inflammatory drugs: Comparative study

Comparison of the mechanisms of DNA damage following photoexcitation and chemiexcitation

In this review, we compare the mechanisms and consequences of electronic excitation of DNA via photon absorption or photosensitization, as well as by chemically induced generation of excited states. The absorption of UV radiation by DNA is known to produce cyclobutane pyrimidine dimers (CPDs) and thymine pyrimidone photoproducts. Photosensitizers are known to enable such transformations using UV-A and visible light by generating triplet species able to transfer energy to DNA. Conversely, chemiexcitation of DNA is a process related to the formation of high energy peroxides whose decomposition leads to triplet excited species. In practice, both photoexcitation and chemiexcitation produce reactive excited species able to promote some DNA nucleobases to their excited state. We discuss the effect of epigenetic methylation modifications of DNA and the role of endogenous and exogenous photosensitizers on the formation of DNA photoproducts via triplet-triplet energy transfer as well as oxidative DNA damages. The mechanisms of pathogenic pathway involving the generation of CPDs via chemiexcitation (namely dark CPDs, dCPDs) are discussed and compared with photoexcitation considering their spatiotemporal characteristics. Recognition of the multifaceted noxious effects of UV radiation opens new horizons for the development of effective electronically excited quenchers, thereby providing a crucial step toward mitigating DNA photodamage.

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.

Functionalized fennel extract-mediated alumina/cerium oxide nanocomposite potentiometric sensor for the determination of diclofenac sodium medication

The current work suggests a new, ultrasensitive green functionalized sensor for the determination of anti-inflammatory medication diclofenac sodium (DCF). Alumina (Al2O3) and cerium oxide (CeO2) nanoparticles (NPs) have attracted great interest for their use as outstanding and electroactive nanocomposite in potentiometric and sensory research due to their ultrafunctional potential. The formed nanoparticles have been confirmed using various spectroscopic and microscopic techniques. The fennel extract-mediated Al2O3/CeO2 nanocomposite (Al2O3/CeO2 NCS) modified coated wire membrane sensor developed in this study was used to quantify DCF in bulk and commercial products. Diclofenac sodium was coupled with phosphomolybdic acid (PMA) to generate diclofenac phosphomolybdate (DCF-PM) as an active ion-pair in the existence of polyvinyl chloride (PVC) and o-nitrophenyl octyl ether (o-NPOE). Clear peaks at 270, and 303 nm with band gaps of 4.59 eV and 4.09 eV were measured using UV-vis spectroscopy of Al2O3 and CeO2, respectively. The crystallite sizes of the formed nanoparticles were XRD-determined to be 30.13 ± 8, 17.72 ± 3, and 35.8 ± 0.5 nm for Al2O3, CeO2, and Al2O3/CeO2 NCS, respectively. The developed sensor showed excellent response for the measurement and assay of DCF, with a linearity between 1.0 × 10-9 and 1.0 × 10-2 mol L-1. EmV = (57.76) log [DCF] +622.69 was derived. On the other hand, the typical type DCF-PM presented a potentiometric response range of 1.0 × 10-5-1.0 × 10-2 mol L-1 and a regression equation of EmV = (56.97) log [DCF]+367.16. The functionalized sensor that was proposed was successful in determining DCF in its commercial tablets with percent recovery 99.95 ± 0.3. Method validation has been used to improve the suitability of the suggested potentiometric technique, by studying various parameters with respect to the international council harmonization requirements for analytical methodologies.

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.

Characterization of chitosan- and β-cyclodextrin-modified forms of magnesium-doped hydroxyapatites as enhanced carriers for levofloxacin: loading, release, and anti-inflammatory properties

An advanced form of magnesium-rich hydroxyapatite (Mg·HAP) was modified with two types of biopolymers, namely chitosan (CH/Mg·HAP) and β-cyclodextrin (CD/Mg·HAP), producing two types of bio-composites. The synthesized materials were developed as enhanced carriers for levofloxacin to control its loading, release, and anti-inflammatory properties. The polymeric modification significantly improved the loading efficiency to 281.4 mg g-1 for CH/Mg·HAP and 332.4 mg g-1 for CD/Mg·HAP compared with 218.3 mg g-1 for Mg·HAP. The loading behaviors were determined using conventional kinetic and isotherm models and mathematical parameters of new equilibrium models (the monolayer model of one energy). The estimated density of effective loading sites (Nm (LVX) = 88.03 mg g-1 (Mg·HAP), 115.8 mg g-1 (CH/Mg·HAP), and 138.5 mg g-1 (CD/Mg·HAP)) illustrates the markedly higher loading performance of the modified forms of Mg·HAP. Moreover, the loading energies (<40 kJ mol-1) in conjunction with the capacity of each loading site (n > 1) and Gaussian energies (<8 kJ mol-1) signify the physical trapping of LVX molecules in vertical orientation. The addressed materials validate prolonged and continuous release behaviors. These behaviors accelerated after the modification procedures, as the complete release was identified after 160 h (CH/Mg·HAP) and 200 h (CD/Mg·HAP). The releasing behaviors are regulated by both diffusion and erosion mechanisms, according to the kinetic investigations and diffusion exponent analysis (>0.45). The entrapping of LVX into Mg·HAP induces its anti-inflammatory properties against the generation of cytokines (IL-6 and IL-8) in human bronchial epithelia cells (NL20), and this effect displays further enhancement after the integration of chitosan and β-cyclodextrin.

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.

Discovery of novel benzimidazole acyclic C-nucleoside DNA intercalators halting breast cancer growth

Breast cancer continues to be the most frequent cancer worldwide. In practice, successful clinical outcomes were achieved via targeting DNA. Along with the advances in introducing new DNA-targeting agents, the "sugar approach" design was employed herein to develop new intercalators bearing pharmacophoric motifs tethered to carbohydrate appendages. Accordingly, new benzimidazole acyclic C-nucleosides were rationally designed, synthesized and assayed via MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay to evaluate their cytotoxicity against MCF-7 and MDA-MB-231 breast cancer cells compared to normal fibroblasts (Wi-38), compared to doxorubicin. (1S,2R,3S,4R)-2-(1,2,3,4,5-Pentahydroxy)pentyl-1H-5,6-dichlorobenzimidazole 7 and (1S,2R,3S,4R)-2-(1,2,3,4,5-pentahydroxy)pentyl-1H-naphthimidazole 13 were the most potent and selective derivatives against MCF-7 (half-maximal inhibitory concentration [IC50 ] = 0.060 and 0.080 µM, selectivity index [SI] = 9.68 and 8.27, respectively) and MDA-MB-231 cells (IC50  = 0.299 and 0.166 µM, SI = 1.94 and 3.98, respectively). Thus, they were identified as the study hits for mechanistic studies. Both derivatives induced DNA damage at 0.24 and 0.29 μM, respectively. The DNA damage kinetics were studied compared to doxorubicin, where they both induced faster damage than doxorubicin. This indicated that 7 and 13 showed a more potent DNA-damaging effect than doxorubicin. Docking simulations within the DNA double strands highlighted the role of both the heterocyclic core and the sugar side chain in exhibiting key H-bond interactions with DNA bases.

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.

Inclusion of Nitrofurantoin into the Realm of Cancer Chemotherapy via Biology-Oriented Synthesis and Drug Repurposing

Structural modifications of the antibacterial drug nitrofurantoin were envisioned, employing drug repurposing and biology-oriented drug synthesis, to serve as possible anticancer agents. Eleven compounds showed superior safety in non-cancerous human cells. Their antitumor efficacy was assessed on colorectal, breast, cervical, and liver cancer cells. Three compounds induced oxidative DNA damage in cancer cells with subsequent cellular apoptosis. They also upregulated the expression of Bax while downregulated that of Bcl-2 along with activating caspase 3/7. The DNA damage induced by these compounds, demonstrated by pATM nuclear shuttling, was comparable in both MCF7 and MDA-MB-231 (p53 mutant) cell lines. Mechanistic studies confirmed the dependence of these compounds on p53-mediated pathways as they suppressed the p53-MDM2 interaction. Indeed, exposure of radiosensitive prostatic cancer cells to low non-cytotoxic concentrations of compound 1 enhanced the cytotoxic response to radiation indicating a possible synergistic effect. In vivo antitumor activity was verified in an MCF7-xenograft animal model.

Mechanism-Based Sonodynamic–Chemo Combinations against Triple-Negative Breast Cancer

Due to its noninvasive nature, site-confined irradiation, and high tissue penetrating capabilities, ultrasound (US)-driven sonodynamic treatment (SDT) has been proven to have broad application possibilities in neoplastic and non-neoplastic diseases. However, the inefficient buildup of sonosensitizers in the tumor site remarkably impairs SDT efficiency. The present work proposes a deep-penetrating sonochemistry nanoplatform (Pp18-lipos@SRA737&DOX, PSDL) comprising Pp18 liposomes (Pp18-lipos, Plipo), SRA737 (a CHK1 inhibitor), and doxorubicin (DOX) for the controlled formation of reactive oxygen species (ROS) and release of DOX and SRA737 upon US activation, therefore increasing chemotherapeutic effectiveness and boosting SDT efficacy. Therein, the antitumor activities of DOX have been attributed to its intercalation into the nucleus DNA and induction of cell apoptosis. CHK1 evolved to respond to DNA damage and repair the damage via cell cycle progression. SRA737 is a potent and orally bioavailable clinical drug candidate for inhibiting CHK1, demonstrating adjuvant anticancer effect in vitro and in vivo. It was interesting to find that SRA737 carried into Plipo@DOX could significantly alleviate G2/M cell cycle arrest and aggravate DNA double-strand injuries, resulting in significant cell death. The developed US-switchable nanosystem provides a promising strategy for augmenting sono-chemotherapy against breast cancer controllably and precisely.

Two novel "release-on-demand" fluorescent biosensors for probing UV-induced DNA damage induced in single stranded and double stranded DNA: Comparative study

Light in the UVC spectral region damages both single-strand (ssDNA) and double-strand DNA (dsDNA), and contributes to the formation of mutagenic photoproducts. In-vivo studies show greater damage for ssDNA compared to dsDNA. However, excited-state spectroscopy shows that dsDNA has longer excited-state lifetime than ssDNA, which increases the probability of damage for dsDNA. However, lack of a direct comparison of in-vitro ssDNA and dsDNA damage rates precludes the development of a model that elucidates the molecular factors responsible for damage. In this work, two novel sensitive "release-on-demand" biosensors are developed for the selective probing of DNA-damage and comparing the rate of DNA damage in ssDNA and dsDNA. The two biosensors involve the use of EvaGreen and Hoechst dyes for the sensitive probing of DNA-damage. The results show that ssDNA is damaged at a faster rate than dsDNA in the presence of UVC light (200-295 nm). Furthermore, we examined the effect of G/C composition on the damage rate for mostly A/T ssDNA and dsDNA oligonucleotides. Our results show that DNA damage rates are highly dependent on the fraction of guanines in the sequence, but that in-vitro dsDNA always exhibits an overall slower rate of damage compared to ssDNA, essentially independent of sequence.

Investigation of nucleic acid damage induced by a novel ruthenium anti-cancer drug using multiple analytical techniques: Sequence specificity and damage kinetics

Cis-diacetonitrilo-bis(bipyridine) ruthenium(II) chloride is a recently introduced cis-platin analogue that has anti-cancer properties with lower side effects. However, the sequence dependence of its DNA damaging mechanism is unclear. Here, we present a simple, sensitive, multiplexed mix-and-read assay for ascertaining the molecular mechanism of DNA damage induced by the studied ruthenium complex (Ru-complex). The damage kinetics and sequence specificity for the Ru-complex induced DNA damage are examined by studying the induced damage in various oligonucleotide sequences by EvaGreen-DNA intercalator probe. High-through-put measurements were established using a 96-well microplate platform that allows multiple sequences to be measured simultaneously. The results show that the extent of damage increases with an increasing number of guanines, with considerable amount of damage at GA, GT and GC sites, in particular. Furthermore, the interaction of Ru-complex with DNA was confirmed using thermal analysis and MALDI-TOF-MS. Results indicate that the activated Ru-complex preferentially binds via both mono- and di-adduct formation at G and GG sites, respectively. Moreover, the developed method was successfully applied for the determination of the potency of the studied Ru-complex to induce DNA damage in K-Ras and N-Ras family of genes, one of the most common oncogenic events in cancer.

Photodegradation of Anti-Inflammatory Drugs: Stability Tests and Lipid Nanocarriers for Their Photoprotection

The present paper provides an updated overview of the methodologies applied in photodegradation studies of non-steroidal anti-inflammatory drugs. Photostability tests, performed according to international standards, have clearly demonstrated the photolability of many drugs belonging to this class, observed during the preparation of commercial forms, administration or when dispersed in the environment. The photodegradation profile of these drugs is usually monitored by spectrophotometric or chromatographic techniques and in many studies the analytical data are processed by chemometric procedures. The application of multivariate analysis in the resolution of often-complex data sets makes it possible to estimate the pure spectra of the species involved in the degradation process and their concentration profiles. Given the wide use of these drugs, several pharmaceutical formulations have been investigated to improve their photostability in solution or gel, as well as the pharmacokinetic profile. The use of lipid nanocarriers as liposomes, niosomes or solid lipid nanoparticles has demonstrated to both minimize photodegradation and improve the controlled release of the entrapped drugs.

Photosensitizing Medications and Skin Cancer: A Comprehensive Review

(1) The incidence of skin cancer is increasing in the United States (US) despite scientific advances in our understanding of skin cancer risk factors and treatments. In vitro and in vivo studies have provided evidence that suggests that certain photosensitizing medications (PSMs) increase skin cancer risk. This review summarizes current epidemiological evidence on the association between common PSMs and skin cancer. (2) A comprehensive literature search was conducted to identify meta-analyses, observational studies and clinical trials that report on skin cancer events in PSM users. The associated risks of keratinocyte carcinoma (squamous cell carcinoma and basal cell carcinoma) and melanoma are summarized, for each PSM. (3) There are extensive reports on antihypertensives and statins relative to other PSMs, with positive and null findings, respectively. Fewer studies have explored amiodarone, metformin, antimicrobials and vemurafenib. No studies report on the individual skin cancer risks in glyburide, naproxen, piroxicam, chlorpromazine, thioridazine and nalidixic acid users. (4) The research gaps in understanding the relationship between PSMs and skin cancer outlined in this review should be prioritized because the US population is aging. Thus the number of patients prescribed PSMs is likely to continue to rise.

Insight into chitosan/zeolite-A nanocomposite as an advanced carrier for levofloxacin and its anti-inflammatory properties; loading, release, and anti-inflammatory studies

Chitosan/zeolite-A nanocomposite (CH/ZA) was synthesized as a potential carrier for levofloxacin (LVOX) of enhanced technical properties. The CH/ZA composite displayed enhanced loading capacity (425 mg/g) as compared to chitosan (188.8 mg/g) and zeolite-A (234.6 mg/g). The loading behavior follows Pseudo-Second-order and Langmuir as kinetic and isotherm models. The equilibrium studies, Gaussian energy (8.15 KJ/mol), and thermodynamic parameters demonstrate homogenous and monolayer loading by complex chemical and physical reactions that are of spontaneous and exothermic nature. The CH/ZA composite is of slow and continuous release profile (200h) with 94.3% as the maximum release percentage. The release reactions are of non-Fickian behavior involving both diffusion and erosion mechanisms. The loading of LVOX into CH/ZA induced its anti-inflammatory effect against the cytokine production (IL-6 and IL-8) within the human bronchial epithelia cells (NL20). The cytotoxicity studies on the normal cells demonstrated a high safety value for the composite.