Mass spectrometry-based metabolomics approach and in vitro assays revealed promising role of 2,3-dihydroquinazolin-4(1H)-one derivatives against colorectal cancer cell lines.

Colorectal cancer (CRC) is the most frequent form of gastrointestinal cancer and one of the major causes of human mortality worldwide. Many of the current CRC therapies have limitations due to multidrug resistance and/or severe side effects. Quinazoline derivatives are promising lead compounds with a wide range of pharmacological actions. In this study, the effect of seven synthesized 2,3-dihydroquinazolin-4(1H)-one analogues as potential anticancer agents against two CRC cell lines (HCT116 and SW480) was investigated using cell viability proliferation, migration, adhesion and invasion assays. A liquid chromatography-mass spectrometry (LC-MS/MS) metabolomics approach was used to identify the underlying biochemical pathways disturbed in treated-HCT116 cells. Cell viability proliferation assay revealed that four compounds (C2, C3, C5, and C7) had IC50 < 10 µM with C5 displaying the most potent cytotoxic effect (IC50 1.4 and 0.3 µM against HCT116 and SW480, respectively). Additionally, the compounds showed suppression of wound closure after 72 h, and both C2 and C5 significantly decreased the number of adherent cells and suppressed HCT116 cells invasion. Metabolomics study revealed that C5 induced significant perturbations in the level of several metabolites including spermine, polyamines, glutamine, creatine and carnitine, and altered biochemical processes essential for cell proliferation and progression such as amino acids biosynthesis and metabolism, redox homeostasis, energy related processes (e.g., fatty acid oxidation, second Warburg like effect) and one-carbon metabolism. Our findings indicate that 2,3-dihydroquinazolin-4(1H)-one analogues, particularly C5, have promising anticancer properties, and shed light on the role of metabolomics in identifying new therapeutic targets and providing better understanding of the pathways altered in treated cancer cells.

Molecular and metabolic alterations of 2,3-dihydroquinazolin-4(1H)-one derivatives in prostate cancer cell lines.

Prostate cancer (PC) is the second most common tumor in males worldwide. The lack of effective medication and the development of multidrug resistance towards current chemotherapeutic agents urge the need to discover novel compounds and therapeutic targets for PC. Herein, seven synthesized 2,3-dihydroquinazolin-4(1H)-one analogues were evaluated for their anticancer activity against PC3 and DU145 cancer cell lines using MTT, scratch-wound healing, adhesion and invasion assays. Besides, a liquid chromatography mass spectrometry (LC-MS)-based metabolomics approach was followed to identify the biochemical pathways altered in DU145 cancer cells upon exposure to dihydroquinazolin derivatives. The seven compounds showed sufficient cytotoxicity and significantly suppressed DU145 and PC3 migration after 48 and 72 h. C2 and C5 had the most potent effect with IC50 < 15 µM and significantly inhibited PC cell adhesion and invasion. Metabolomics revealed that C5 disturbed the level of metabolites involved in essential processes for cancer cell proliferation, progression and growth including energy production, redox homeostasis, amino acids and polyamine metabolisms and choline phospholipid metabolism. The data presented herein highlighted the importance of these compounds as potential anticancer agents particularly C5, and pointed to the promising role of metabolomics as a new analytical approach to investigate the antiproliferative activity of synthesized compounds and identify new therapeutic targets.

Antitubercular, Cytotoxicity, and Computational Target Validation of Dihydroquinazolinone Derivatives.

A series of 2,3-dihydroquinazolin-4(1H)-one derivatives (3a-3m) was screened for in vitro whole-cell antitubercular activity against the tubercular strain H37Rv and multidrug-resistant (MDR) Mycobacterium tuberculosis (MTB) strains. Compounds 3l and 3m with di-substituted aryl moiety (halogens) attached to the 2-position of the scaffold showed a minimum inhibitory concentration (MIC) of 2 µg/mL against the MTB strain H37Rv. Compound 3k with an imidazole ring at the 2-position of the dihydroquinazolin-4(1H)-one also showed significant inhibitory action against both the susceptible strain H37Rv and MDR strains with MIC values of 4 and 16 µg/mL, respectively. The computational results revealed the mycobacterial pyridoxal-5'-phosphate (PLP)-dependent aminotransferase (BioA) enzyme as the potential target for the tested compounds. In vitro, ADMET calculations and cytotoxicity studies against the normal human dermal fibroblast cells indicated the safety and tolerability of the test compounds 3k-3m. Thus, compounds 3k-3m warrant further optimization to develop novel BioA inhibitors for the treatment of drug-sensitive H37Rv and drug-resistant MTB.

Anti-tubercular activity and molecular docking studies of indolizine derivatives targeting mycobacterial InhA enzyme.

A series of 1,2,3-trisubstituted indolizines (2a-2f, 3a-3d, and 4a-4c) were screened for in vitro whole-cell anti-tubercular activity against the susceptible H37Rv and multidrug-resistant (MDR) Mycobacterium tuberculosis (MTB) strains. Compounds 2b-2d, 3a-3d, and 4a-4c were active against the H37Rv-MTB strain with minimum inhibitory concentration (MIC) ranging from 4 to 32 µg/mL, whereas the indolizines 4a-4c, with ethyl ester group at the 4-position of the benzoyl ring also exhibited anti-MDR-MTB activity (MIC = 16-64 µg/mL). In silico docking study revealed the enoyl-acyl carrier protein reductase (InhA) and anthranilate phosphoribosyltransferase as potential molecular targets for the indolizines. The X-ray diffraction analysis of the compound 4b was also carried out. Further, a safety study (in silico and in vitro) demonstrated no toxicity for these compounds. Thus, the indolizines warrant further development and may represent a novel promising class of InhA inhibitors and multi-targeting agents to combat drug-sensitive and drug-resistant MTB strains.

ADMET Profiling in Drug Discovery and Development: Perspectives of In Silico, In Vitro and Integrated Approaches.

In the drug discovery setting, undesirable ADMET properties of a pharmacophore with good predictive power obtained after a tedious drug discovery and development process may lead to late-stage attrition. The earlystage ADMET profiling has brought a new dimension to lead drug development. Although several high-throughput in vitro models are available for ADMET profiling, the in silico methods are gaining more importance because of their economic and faster prediction ability without the requirements of tedious and expensive laboratory resources. Nonetheless, in silico ADMET tools alone are not accurate, and therefore, ideally adopted along with in vitro and or in vivo methods in order to enhance the predictability power. This review summarizes the significance and challenges associated with the application of in silico tools as well as the possible scope of in vitro models for integration to improve the ADMET predictability power of these tools.

Voltammetric Determination of Ascorbic Acid in Pharmaceutical Formulations Using Modified Iodine-Coated Platinum Electrode / Determinación voltamétrica del ácido ascórbico en formulaciones farmacéuticas utilizando un electrodo de platino modificado recubierto de yodo

Background: Despite the high reactivity of the platinum electrode, the iodine-coated platinum electrode shows obvious inertness toward adsorption and surface processes. For that, iodine-coated platinum electrodes accommodate themselves to interesting voltammetric applications. Objectives: This study reports using the modified iodine-coated polycrystalline platinum electrode as a voltammetric sensor for ascorbic acid determination in pharmaceutical formulations. Methods: The developed voltammetric method based on recording cyclic voltammograms of ascorbic acid at iodine-coated electrode The optimized experimental parameters for the determination of ascorbic acid were using 0.1 M KCl as a supporting electrolyte with a scan rate of 50mV/s. Results: The anodic peak related to ascorbic acid oxidation was centered at nearly 0.28V. An excellent and extended linear dependence of the oxidative peak current on the concentration of ascorbic acid was observed in the range 2.84x10-3 - 5.68 mM. The limit of detection (LOD) and limit of quantitation (LOQ) were 1.0 µM and 3.01 µM, respectively, attesting to the method's sensitivity. The investigation for the effect of potential interference from multivitamin tablet ingredients (vitamins B1, B6, B12, folic acid, citric acid, sucrose, glucose, and zinc) indicated specific selectivity toward ascorbic acid and the absence of any electrochemical response toward these components. Recovery results in the range 98.93±2.78 - 99.98±5.20 for spiked standard ascorbic acid in pharmaceutical formulations further confirmed the potential applicability of the developed method for the determination of ascorbic acid in real samples. Conclusions: The developed method was successfully applied to the analysis of ascorbic acid (vitamin C), and the obtained results were in good agreement with the labeled values; besides, the statistical tests indicated no significant difference at p=0.05 with a 95% confidence level

Antecedentes: A pesar de su alta reactividad, el electrodo de platino recubierto de yodo muestra una inercia evidente hacia la adsorción y los procesos superficiales. Por ello, los electrodos de platino recubiertos de yodo se adaptan a interesantes aplicaciones voltamétricas. Objetivos: Este estudio informa sobre el uso del electrodo de platino policristalino recubierto de yodo modificado como sensor voltamétrico para la determinación del ácido ascórbico en formulaciones farmacéuticas. Métodos: El método voltamétrico desarrollado se basa en el registro de voltamperogramas cíclicos del ácido ascórbico en el electrodo recubierto de yodo Los parámetros experimentales optimizados para la determinación del ácido ascórbico fueron utilizando KCl 0,1 M como electrolito de soporte con una velocidad de barrido de 50mV/s. Resultados: El pico anódico relacionado con la oxidación del ácido ascórbico se centró en casi 0,28V. Se observó una excelente y extendida dependencia lineal de la corriente del pico oxidativo con respecto a la concentración de ácido ascórbico en el rango 2,84x10-3 - 5,68 mM. El límite de detección (LOD) y el límite de cuantificación (LOQ) fueron 1,0 µM y 3,01 µM, respectivamente, lo que demuestra la sensibilidad del método. La investigación del efecto de la interferencia potencial de los ingredientes de las tabletas multivitamínicas (vitaminas B1, B6, B12, ácido fólico, ácido cítrico, sacarosa, glucosa y zinc) indicó una selectividad específica hacia el ácido ascórbico y la ausencia de cualquier respuesta electroquímica hacia estos componentes. Los resultados de recuperación en el rango de 98,93±2,78 - 99,98±5,20 para el ácido ascórbico estándar adicionado en formulaciones farmacéuticas confirmaron además la potencial aplicabilidad del método desarrollado para la determinación del ácido ascórbico en muestras reales. Conclusiones: El método desarrollado se aplicó con éxito al análisis de ácido ascórbico (vitamina C), y los resultados obtenidos coincidieron con los valores etiquetados; además, las pruebas estadísticas no indicaron diferencias significativas a p=0,05 con un nivel de confianza del 95%

Current advances in the clinical development of anti-tubercular agents.

Tuberculosis (TB) is a communicable airborne infectious disease caused by the Mycobacterium tuberculosis (MTB) that primarily affects the lungs, and can disseminate to other parts of the body. MTB is one of the most dangerous pathogens, killing about 1.4 million people annually worldwide. Although the standard treatment of TB is comprised of four anti-TB drugs, the emergence of multidrug-resistant (MDR) and extensive drug-resistant (XDR) strains in the recent past and associated side effects have affected the tailor-made regimens. Notably, existing therapies approved by the World Health Organisation (WHO) can only treat less than 50% of drug-resistant TB. Therefore, an expeditious pace in the TB research is highly needed in search of effective, affordable, least toxic novel drugs with shorter regimens to reach the goals viz. 2020 milestones End TB strategy set by the WHO. Currently, twenty-three drug-like molecules are under investigation in different stages of clinical trials. These newer agents are expected to be effective against the resistant strains. This article summarizes the properties, merits, demerits, and the probability of their success as novel potential therapeutic agents.

n-3 polyunsaturated N-acylethanolamines are CB2 cannabinoid receptor-preferring endocannabinoids.

Anandamide, the first identified endogenous cannabinoid and TRPV1 agonist, is one of a series of endogenous N-acylethanolamines, NAEs. We have generated novel assays to quantify the levels of multiple NAEs in biological tissues and their rates of hydrolysis through fatty acid amide hydrolase. This range of NAEs was also tested in rapid response assays of CB1, CB2 cannabinoid and TRPV1 receptors. The data indicate that PEA, SEA and OEA are not endocannabinoids or endovanilloids, and that the higher endogenous levels of these metabolites compared to polyunsaturated analogues are a correlate of their slow rates of hydrolysis. The n-6 NAEs (AEA, docosatetraenoyl and docosapentaenoyl derivatives) activated both CB1 and CB2 receptors, as well as TRPV1 channels, suggesting them to be 'genuine' endocannabinoids and 'endovanilloids'. The n-3 NAEs (eicosapentaenoyl, docosapentaenoyl and docosahexaenoyl derivatives) activated CB2 receptors and some n-3 NAEs (docosapentaenoyl and docosahexaenoyl derivatives) also activated TRPV1 channels, but failed to activate the CB1 receptor. We hypothesise that the preferential activation of CB2 receptors by n-3 PUFA NAEs contributes, at least in some part, to their broad anti-inflammatory profile.

Cannabinoid ligands, receptors and enzymes: Pharmacological tools and therapeutic potential.

Endocannabinoids have been identified to have roles in numerous physiological and pathological processes. Largely due to the association of the effects of Cannabis administration on mental states, the CNS impact of the endocannabinoid system has been the most intensively studied. Here, we provide a brief summary of the endocannabinoid system, comprising the receptors and the multiple endogenous lipid derivatives which activate them, as well as the enzymes which control the levels of these lipid derivatives. We identify pharmacological tools which may be used to interrogate the endocannabinoid system, as well as current and future options to exploit the system in the clinic.