Design, synthesis, molecular docking as histone deacetylase (HDAC8) inhibitors, cytotoxicity and antibacterial evaluation of novel 6-(4-(4-aminophenylsulfonyl)phenylamino)-5H-benzo[a]phenoxazin-5-one derivatives

Anticancer Activity of Benzo[a]phenoxazine Compounds Promoting Lysosomal Dysfunction

Specific cancer therapy remains a problem to be solved. Breast and colorectal cancer are among the cancers with the highest prevalence and mortality rates. Although there are some therapeutic options, there are still few effective agents for those cancers, which constitutes a clinical problem that requires further research efforts. Lysosomes play an important role in cancer cells' survival, and targeting lysosomes has gained increased interest. In recent years, our team has been synthetizing and testing novel benzo[a]phenoxazine derivatives, as they have been shown to possess potent pharmacological activities. Here, we investigated the anticancer activity of three of the most potent derivatives from our library, C9, A36, and A42, on colorectal- and breast-cancer-derived cell lines, and compared this with the effect on non-neoplastic cell lines. We observed that the three compounds were selective for the cancer cells, namely the RKO colorectal cancer cell line and the MCF7 breast cancer cell line. In both models, the compounds reduced cell proliferation, cell survival, and cell migration, accumulated on the lysosome, and induced cell death accompanied by lysosomal membrane permeabilization (LMP), increasing the intracellular pH and ROS accumulation. Our results demonstrated that these compounds specifically target lysosomes from cancer cells, making them promising candidates as LMP inducers for cancer therapy.

In Vitro and In Vivo Biological Evaluation of Novel 1,4-Naphthoquinone Derivatives as Potential Anticancer Agents

A novel library of naphthoquinone derivatives (3-5 aa) was synthesized and evaluated for their anticancer properties. Specifically, compounds 5 i, 5 l, 5 o, 5 q, 5 r, 5 s, 5 t, and 5 v demonstrated superior cytotoxic activity against the cancer cell lines that were studied. All the studied compounds exhibited a higher selectivity index (SI) and a favourable safety profile than the standard drug doxorubicin. Notably, compound 5 v displayed a greater cytotoxic effect on MCF-7 cells (IC50=1.2 μM, and 0.9 μM at 24 h and 48 h, respectively) compared to the standard drug doxorubicin (IC50=2.4 μM, and 2.1 μM at 24 h and 48 h, respectively). To further investigate the mechanism of cytotoxic effect, additional anticancer studies were conducted with 5 v in MCF-7 cells. The studies are including morphological changes, AO/EB (acridine orange/ethidium bromide) double staining, apoptosis analysis, cell colony assay, SDS-PAGE and Western blotting, cell cycle analysis, and detecting reactive oxygen species (ROS) assay. The findings showed that 5 v triggered cytotoxic effects in MCF-7 cells through the initiation of cell cycle arrest at the G1/S phase and necrosis. In vivo ecotoxicity studies indicated that 5 v had lower toxicity towards zebrafish larvae (LC50=50.15 μM) and had an insignificant impact on cardiac functions. In vivo xenotransplantation of MCF-7 cells in zebrafish larvae demonstrated a significant reduction in tumour volume in the xenograft. Approximately 95 % of the zebrafish larvae with 5 v xenografts survived after 10 days of the treatment. Finally, a computational modelling study was conducted on four protein receptors, namely ER, EFGR, BRCA1, and VEFGR2. The findings highlight the importance of the aminonaphthoquinone moiety, amide linkage, and propyl thio moiety in enhancing the anticancer properties. 5 v exhibited superior drug-likeness features and docking scores (-9.1, -7.1, -8.9, and -10.9 kcal/mol) compared to doxorubicin (-7.2, -6.1, -6.9, and -7.3 kcal/mol) against ER, EFGR, BRCA1, and VEGFR2 receptors, respectively. Therefore, the notable antitumor effects of naphthoquinone derivatives (3-5 aa) suggest that these molecular frameworks may play a role in the development of promising anticancer agents for cancer treatment.

A New Cu/Fe Layer Double Hydroxide Nanocomposite Exerts Anticancer Effects against PC-3 Cells by Inducing Cell Cycle Arrest and Apoptosis

Prostate cancer treatment poses significant challenges due to its varying aggressiveness, potential for metastasis, and the complexity of treatment options. Balancing the effectiveness of therapies, minimizing side effects, and personalizing treatment strategies are ongoing challenges in managing this disease. Significant advances in the use of nanotechnology for the treatment of prostate cancer with high specificity, sensitivity, and efficacy have recently been made. This study aimed to synthesize and characterize a novel Cu/Fe layer double hydroxide (LDH) nanocomposite for use as an anticancer agent to treat prostate cancer. Cu/Fe LDH nanocomposites with a molar ratio of 5:1 were developed using a simple co-precipitation approach. FT-IR, XRD, SEM, TEM, TGA, and zeta potential analyses confirmed the nanocomposite. Moreover, the MTT cell viability assay, scratch assay, and flow cytometry were utilized to examine the prospective anticancer potential of Cu/Fe LDH on a prostate cancer (PC-3) cell line. We found that Cu/Fe LDH reduced cell viability, inhibited cell migration, induced G1/S phase cell cycle arrest, and triggered apoptotic effect in prostate cancer cells. The findings also indicated that generating reactive oxygen species (ROS) formation could improve the biological activity of Cu/Fe LDH. Additionally, Cu/Fe LDH showed a good safety impact on the normal lung fibroblast cell line (WI-38). Collectively, these findings demonstrate that the Cu/Fe LDH nanocomposite exhibited significant anticancer activities against PC-3 cells and, hence, could be used as a promising strategy in prostate cancer treatment.

Biological Activity of Naphthoquinones Derivatives in the Search of Anticancer Lead Compounds

Naphthoquinones are a valuable source of secondary metabolites that are well known for their dye properties since ancient times. A wide range of biological activities have been described highlighting their cytotoxic activity, gaining the attention of researchers in recent years. In addition, it is also worth mentioning that many anticancer drugs possess a naphthoquinone backbone in their structure. Considering this background, the work described herein reports the evaluation of the cytotoxicity of different acyl and alkyl derivatives from juglone and lawsone that showed the best activity results from a etiolated wheat coleoptile bioassay. This bioassay is rapid, highly sensitive to a wide spectrum of activities, and is a powerful tool for detecting biologically active natural products. A preliminary cell viability bioassay was performed on cervix carcinoma (HeLa) cells for 24 h. The most promising compounds were further tested for apoptosis on different tumoral (IGROV-1 and SK-MEL-28) and non-tumoral (HEK-293) cell lines by flow cytometry. Results reveal that derivatives from lawsone (particularly derivative 4) were more cytotoxic on tumoral than in non-tumoral cells, showing similar results to those obtained with of etoposide, which is used as a positive control for apoptotic cell death. These findings encourage further studies on the development of new anticancer drugs for more directed therapies and reduced side effects with naphthoquinone skeleton.

Novel Benzo[a]phenoxazinium Chlorides Functionalized with Sulfonamide Groups as NIR Fluorescent Probes for Vacuole, Endoplasmic Reticulum, and Plasma Membrane Staining

The demand for new fluorophores for different biological target imaging is increasing. Benzo[a]phenoxazine derivatives are fluorochromophores that show promising optical properties for bioimaging, namely fluorescent emission at the NIR of the visible region, where biological samples have minimal fluorescence emission. In this study, six new benzo[a]phenoxazinium chlorides possessing sulfonamide groups at 5-amino-positions were synthesized and their optical and biological properties were tested. Compared with previous probes evaluated using fluorescence microscopy, using different S. cerevisiae strains, these probes, with sulfonamide groups, stained the vacuole membrane and/or the perinuclear membrane of the endoplasmic reticulum with great specificity, with some fluorochromophores capable of even staining the plasma membrane. Thus, the addition of a sulfonamide group to the benzo[a]phenoxazinium core increases their specificity and attributes for the fluorescent labeling of cell applications and fractions, highlighting them as quite valid alternatives to commercially available dyes.

Targeting Lysosomes in Colorectal Cancer: Exploring the Anticancer Activity of a New Benzo[a]phenoxazine Derivative

Colorectal cancer (CRC) has been ranked as one of the cancer types with a higher incidence and one of the most mortal. There are limited therapies available for CRC, which urges the finding of intracellular targets and the discovery of new drugs for innovative therapeutic approaches. In addition to the limited number of effective anticancer agents approved for use in humans, CRC resistance and secondary effects stemming from classical chemotherapy remain a major clinical problem, reinforcing the need for the development of novel drugs. In the recent years, the phenoxazines derivatives, Nile Blue analogues, have been shown to possess anticancer activity, which has created interest in exploring the potential of these compounds as anticancer drugs. In this context, we have synthetized and evaluated the anticancer activity of different benzo[a]phenoxazine derivatives for CRC therapy. Our results revealed that one particular compound, BaP1, displayed promising anticancer activity against CRC cells. We found that BaP1 is selective for CRC cells and reduces cell proliferation, cell survival, and cell migration. We observed that the compound is associated with reactive oxygen species (ROS) generation, accumulates in the lysosomes, and leads to lysosomal membrane permeabilization, cytosolic acidification, and apoptotic cell death. In vivo results using a chicken embryo choriollantoic membrane (CAM) assay showed that BaP1 inhibits tumor growth, angiogenesis, and tumor proliferation. These observations highlight that BaP1 as a very interesting agent to disturb and counteract the important roles of lysosomes in cancer and suggests BaP1 as a promising candidate to be exploited as new anticancer lysosomal-targeted agent, which uses lysosome membrane permeabilization (LMP) as a therapeutic approach in CRC.

Antibacterial and Antibiofilm Potency of Menadione Against Multidrug-Resistant S. aureus

Menadione is an analogue of 1,4-naphthoquinone (1,4-NQ) that possesses enormous pharmaceutical potential. The minimum inhibitory concentration (MIC) of menadione was determined against eighteen pathogens of the ESKAPE category, including thirteen multidrug-resistant (MDR) and five standard strains. From a total of eighteen pathogens, five strains of S. aureus (four: MDR and one: Standard strain) were considered further for detailed studies. This study included the determination of minimum bactericidal concentration (MBC), time-kill assay, scanning electron microscopic technique (SEM), and detection of reactive oxygen species (ROS). Additionally, the effect of menadione on biofilms of three strains of S. aureus was performed through crystal violet assay, SEM, and confocal laser scanning microscopy (CLSM). Menadione exerted substantial antibacterial activity against S. aureus (S8, S9, NCIM 5021) at a lower MIC (64 µg/mL). Whereas, the MIC of 256 µg/mL was displayed against J2 and J4 (MDR and biofilm-forming strains). The time-killing effect of menadione against S. aureus strains was observed after 9 h at MBCs of 64 µg/mL (NCIM 5021), 128 µg/mL (S8, S9), and 512 µg/mL (J2, J4). Enhanced levels of ROS in all five S. aureus were observed in presence of menadione (MICs and MBCs). The relation of enhanced ROS due to menadione activity invigorated us to explore its effect on S. aureus biofilms. We report menadione-mediated inhibition (> 90%) of biofilm formation (at respective MICs) and effect on preformed biofilms (> 85%) at 1024 µg/mL. Menadione possessing antibacterial and antibiofilm potentials are imperative in the era of multidrug resistance developed by bacterial pathogens.

Design, synthesis, characterization, enzymatic inhibition evaluations, and docking study of novel quinazolinone derivatives

In this study, novel quinazolinone derivatives 7a-n were synthesized and evaluated against metabolic enzymes including α-glycosidase, acetylcholinesterase, butyrylcholinesterase, human carbonic anhydrase I, and II. These compounds exhibited high inhibitory activities in comparison to used standard inhibitors with K_i values in the range of 19.28-135.88 nM for α-glycosidase (K_i value for standard inhibitor = 187.71 nM), 0.68-23.01 nM for acetylcholinesterase (K_i value for standard inhibitor = 53.31 nM), 1.01-29.56 nM for butyrylcholinesterase (K_i value for standard inhibitor = 58.16 nM), 10.25-126.05 nM for human carbonic anhydrase I (K_i value for standard inhibitor = 248.18 nM), and 13.46-178.35 nM for human carbonic anhydrase II (K_i value for standard inhibitor = 323.72). Furthermore, the most potent compounds against each enzyme were selected in order to evaluate interaction modes of these compounds in the active site of the target enzyme. Cytotoxicity assay of the title compounds 7a-n against cancer cell lines MCF-7 and LNCaP demonstrated that these compounds do not show significant cytotoxic effects.

Simple Fluorescence Turn-On Chemosensor for Selective Detection of Ba2+ Ion and Its Live Cell Imaging

A phenoxazine-based fluorescence chemosensor 4PB [(4-(tert-butyl)-N-(4-((4-((5-oxo-5H-benzo[a]phenoxazin-6-yl)amino)phenyl)sulfonyl)phenyl)benzamide)] was designed and synthesized by a simple synthetic methods. The 4PB fluorescence chemosensor selectively detects Ba²⁺ in the existence of other alkaline metal ions. In addition, 4PB showed high selectivity and sensitivity for Ba²⁺ detection. The detection limit of 4PB was 0.282 μM and the binding constant was 1.0 × 10⁶ M^-1 in CH₃CN/H₂O (97.5:2.5 v/v, HEPES = 1.25 mM, pH 7.3) medium. This chemosensor functioned through the intramolecular charge transfer (ICT) mechanism, which was further confirmed by DFT studies. Live cell imaging in MCF-7 cells confirmed the cell permeability of 4PB and its capability for specific detection of Ba²⁺ in living cells.

Synthesis and Antimicrobial Evaluation of 1,4-Naphthoquinone Derivatives as Potential Antibacterial Agents

1,4-Naphthoquinones are an important class of compounds present in a number of natural products. In this study, a new series of 1,4-naphthoquinone derivatives were synthesized. All the synthesized compounds were tested for in vitro antimicrobial activity. In this present investigation, two Gram-positive and five Gram-negative bacterial strains and one pathogenic yeast strain were used to determine the antibacterial activity. Naphthoquinones tested for its antibacterial potencies, among seven of them displayed better antimicrobial activity against Staphylococcus aureus (S. aureus; 30-70 μg/mL). Some of the tested compounds showed moderate to low antimicrobial activity against Pseudomonas aeruginosa (P. aeruginosa) and Salmonella bongori (S. bongori; 70-150 μg/mL). In addition, most active compounds against S. aureus were evaluated for toxicity to human blood cells using a hemolysis assay. For better understanding, reactive oxygen species (ROS) generation, time-kill kinetic study, and apoptosis, necrosis responses were investigated for three representative compounds.

Highly Flexible Electrospun Hybrid (Polyurethane/Dextran/Pyocyanin) Membrane for Antibacterial Activity via Generation of Oxidative Stress

A hybrid nanofibrous mat consisting of polyurethane, dextran, and 10 wt % of biopigment (i.e., pyocyanin) was facilely fabricated using a direct-conventional electrospinning method. The field emission scanning electron microscopy showed the bead-free fibers with a twisted morphology for the pyocyanin-loaded mat. The addition of pyocyanin enables the unprecedented approach to tailor the hydrophilicity of hybrid mat, as verified from the water contact measurement. Thermomechanical stabilities of electrospun mats were investigated in terms of thermogravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis. The bacterial inhibition test revealed that the antibacterial activity of electrospun mat containing pyocyanin was 98.54 and 90.2% toward Escherichia coli and Staphylococcus aureus, respectively. By the combined efforts of rapid release of pyocyanin and oxidative stress, the PU-dextran-pyocyanin (PUDP) electrospun mat significantly declined the viable cell number that disrupts the cell morphology. Hence, the proposed PUDP electrospun mat must meet the requirements of efficient antimicrobial material in various applications such as disinfectant wiping, food packaging, and textile industries.

Synthesis, molecular docking and biological evaluation of novel 6-(4-(4-aminophenylsulfonyl)phenylamino)-5H-benzo[a]phenothiazin-5-one derivatives

A novel series of 6-(4-(4-aminophenylsulfonyl)phenylamino)-5H-benzo[a]phenothiazin-5-one derivatives have been synthesized and examined for their in vitro antibacterial activity against a panel of Gram-positive and Gram-negative bacteria. Among these, N-(4-(4-(5-oxo-5H-benzo[a]phenothiazin-6-ylamino)phenylsulfonyl)phenyl)-3,5-bis(trifluoromethyl)benzamide (3n) (0.4 μg/mL) and 4-ethyl-N-(4-(4-(5-oxo-5H-benzo[a]phenothiazin-6-ylamino)phenylsulfonyl)phenyl)benzamide (3l) (0.6 μg/mL) systems exhibited a potent inhibitory activity against Gram-positive organism Bacillus subtilis, when compare to the other synthesized compounds. Sparfloxacin (9.76 μg/mL), Norfloxacin (no activity) were employed as the standard drugs. An evaluation of the cytotoxicity of the title compounds (1, 2, 3a-n) revealed that they displayed low toxicity (26-115 mg/L) against cervical cancer cell line (SiHa). The results of these studies suggest that, phenothiazin-5-one derivatives are interesting binding agents for the development of new Gram-positive and Gram-negative antibacterial agents. To understand the interactions with protein receptors, docking simulation was done with crystal structures of B.subtilis (YmaH) and histone deacetylase (HDAC8) to determine the probable binding conformation.