Natural products hybrids: 3,5,4′-Trimethoxystilbene-5,6,7-trimethoxyflavone chimeric analogs as potential cytotoxic agents against diverse human cancer cells

Design, synthesis and evaluation of acetylcholine-antitumor lipid hybrids led to identification of a potential anticancer agent disrupting the CDK4/6-Rb pathway in lung cancer

Hybridization of acetylcholine with antitumor lipids (ATLs) was explored to achieve novel potential anticancer agents. The combination with a 2-stearoxyphenyl moiety substantially enhanced the anticancer activity of the acetylcholine hybrids. Compounds 6, 8, 9 and 10 exhibited pronounced anticancer activities higher than edelfosine and stPEPC and NSC43067. Compounds 6, 8, 9 and 10 also showed broad-spectrum anticancer activity against diverse cancer cells including lung, ovarian, renal, prostate, leukaemia, colon, CNS, melanoma, and breast cancer cells. Compounds 6 and 8 were potent compounds eliciting single digit low micromolar GI50 values. Compound 6 was the most potent against non-small cell lung cancer, ovarian cancer, renal cancer, and prostate cancer. Meanwhile, compound 8 was the most potent against leukaemia, colon cancer, CNS cancer, melanoma, and breast cancer. Exploration of the mechanism of action of compound 6 in A549 non-small cell lung cancer cells showed that it triggers cell cycle arrest in the G0/G1 phase via disruption of the CDK4/6-Rb pathway and induces apoptosis via the activation of caspases, upregulation of BAX and cleavage of PARP. Overall, the results present acetylcholine-ATL hybrids 6 and 8 as potential anticancer agents for possible further development.

2-Dodecyl-6-Methoxycyclohexa-2,5-Diene-1,4-Dione from Averrhoa carambola L. roots: Suppressing hepatocellular carcinoma progression through ROS accumulation and p53 pathway-mediated apoptosis

This study explores the anti-tumor effects of 2-dodecyl-6-methoxycyclohexa-2,5-diene-1,4-dione (DMDD), a compound derived from Averrhoa carambola L roots, on hepatocellular carcinoma (HCC) cells and a xenograft mouse model, focusing on its underlying mechanisms. Cell viability following DMDD treatment was assessed using the CCK-8 assay. Flow cytometry determined changes in cell cycle distribution and apoptosis rates, while migration and invasion capabilities were assessed using wound healing and transwell assays, respectively. Transcriptome sequencing (RNA-seq) was conducted to analyze differential gene expression and pathway enrichment. Z-VAD-FMK, a pan-caspase inhibitor, was used to confirm the apoptotic mechanism induced by DMDD. The expression levels of p53, Bax, Bcl-2, and cleaved caspase 3 were quantified via Western blot analysis. A xenograft mouse model was developed to assess the in vivo effects of DMDD on HCC. DMDD suppressed proliferation, migration, and invasion, and induced apoptosis in Huh7 and Hep3b cells. RNA-seq revealed significant enrichment of p53 and apoptosis signaling pathways among differentially expressed genes. DMDD downregulated Bcl-2 expression and upregulated p53, Bax and cleaved caspase 3. In addition, Z-VAD-FMK partially inhibited DMDD-induced apoptosis. DMDD also inhibited tumor growth in mice. DMDD effectively inhibited tumor growth in HCC cell lines and xenograft models, potentially through ROS elevation and p53-mediated activation of the intrinsic apoptotic pathway.

Exploring cyclopropylamine containing cyanopyrimidines as LSD1 inhibitors: Design, synthesis, ADMET, MD analysis and anticancer activity profiling

In this series we report the structure-based design, synthesis and anticancer activity evaluation of a series of eighteen cyclopropylamine containing cyanopyrimidine derivatives. The computational predictions of ADMET properties revealed appropriate aqueous solubility, high GI absorption, no BBB permeability, no Lipinski rule violations, medium total clearance and no mutagenic, tumorigenic, irritant and reproductive toxic risks for most of the compounds. Compounds VIIb, VIIi and VIIm emerged as the most potent anticancer agents among all compounds evaluated against 60 cancer cell lines through the one-dose (10 µM) sulforhodamine B assay. Further, the multiple dose cell viability studies against cancer cell lines MOLT-4, A549 and HCT-116 revealed results consistent with the one-dose assay, besides sparing normal cell line HEK-293. The three potent compounds also displayed potent LSD1 inhibitory activity with IC50 values of 2.25, 1.80 and 6.08 µM. The n-propyl-thio/isopropyl-thio group bonded to the pyrimidine ring and unsubstituted/ electron donating group (at the para- position) attached to the phenyl ring resulted in enhanced anticancer activity. However, against leukemia cancer, the electron donating isopropyl group remarkably enhanced anti-cancer activity. Our findings provide important leads, which merit further optimization to result in better cancer therapeutics.

Oxidative Stress and Chronic Myeloid Leukemia: A Balance between ROS-Mediated Pro- and Anti-Apoptotic Effects of Tyrosine Kinase Inhibitors

The balanced reciprocal translocation t (9; 22) (q34; q11) and the BCR-ABL fusion gene, which produce p210 bcr-abl protein production with high tyrosine kinase activity, are characteristics of chronic myeloid leukemia, a myeloproliferative neoplasm. This aberrant protein affects several signaling pathways connected to both apoptosis and cell proliferation. It has been demonstrated that tyrosine kinase inhibitor treatment in chronic myeloid leukemia acts by inducing oxidative stress and, depending on its level, can activate signaling pathways responsible for either apoptosis or survival in leukemic cells. Additionally, oxidative stress and reactive oxygen species generation also mediate apoptosis through genomic activation. Furthermore, it was shown that oxidative stress has a role in both BCR-ABL-independent and BCR-ABL-dependent resistance pathways to tyrosine kinases, while patients with chronic myeloid leukemia were found to have a significantly reduced antioxidant level. The ideal environment for tyrosine kinase inhibitor therapy is produced by a favorable oxidative status. We discuss the latest studies that aim to manipulate the redox system to alter the apoptosis of cancerous cells.

Discovery of a stilbenoid-flavanone hybrid as an antitumor Wnt/β-catenin signaling pathway inhibitor

A series of designed stilbenoid-flavanone hybrids featuring sp3-hybridized C2 and C3 atoms of C-ring was evaluated against colorectal cancers presented compounds 4, 17, and 20 as the most potential compounds among explored compounds. Evaluation of the anticancer activity spectrum of compounds 4, 17, and 20 against diverse solid tumors presented compounds 17 and 20 with interesting anticancer spectrum. The potencies of compounds 17 and 20 were assessed in comparison with FDA-approved anticancer drugs. Compound 17 was the, in general, the most potent showing low micromolar GI50 values that were more potent than the standard FDA-approved drugs against several solid tumors including colon, brain, skin, renal, prostate and breast tumors. Compound 17 was subjected for evaluation against normal cell lines and was subjected to a mechanism study in HCT116 colon cancer cells which presented it as an inhibitor of Wnt signaling pathway triggering G2/M cell cycle arrest though activation of p53-p21 pathway as well as intrinsic and extrinsic apoptotic death of colon cancer cells. Compound 17 might be a candidate for further development against diverse solid tumors including colon cancer.

Flavones and Related Compounds: Synthesis and Biological Activity

This review focuses on the synthesis and biological activity of flavones and their related flavonoidic compounds, namely flavonols and aurones. Among the biological activities of natural and synthetic flavones and aurones, their anticancer, antioxidant, and antimicrobial properties are highlighted and detailed in this review. Starting from the structures of natural flavones acting on multiple anticancer targets (myricetin, genkwanin, and other structurally related compounds), new flavone analogs were recently designed and evaluated for their anticancer activity. The most representative compounds and their anticancer activity are summarized in this review. Natural flavones recognized for their antimicrobial properties (baicalein, luteolin, quercetol, apigenin, kaempferol, tricin) have been recently derivatized or structurally modulated by chemical synthetic methods in order to obtain new effective antimicrobial flavonoidic derivatives with improved biological properties. The most promising antimicrobial agents are systematically highlighted in this review. The most applied method for the synthesis of flavones and aurones is based on the oxidative cyclization of o-hydroxychalcones. Depending on the reaction conditions and the structure of the precursor, in some cases, several cyclization products result simultaneously: flavones, flavanones, flavonols, and aurones. Based on the literature data and the results obtained by our research group, our aim is to highlight the most promising methods for the synthesis of flavones, as well as the synthetic routes for the other structurally related cyclization products, such as hydroxyflavones and aurones, while considering that, in practice, it is difficult to predict which is the main or exclusive cyclization product of o-hydroxychalcones under certain reaction conditions.

Functionalized Cyclopentenones with Low Electrophilic Character as Anticancer Agents

In this study were synthesized non-Michael acceptor cyclopentenones (CP) from biomass derivative furfural as anticancer agents. Cyclic enones, both from natural sources and synthetic analogues, have been described as cytotoxic agents. Most of these agents were unsuccessful in becoming valuable therapeutic agents due to toxicity problems derived from unselective critical biomacromolecule alkylation. This may be caused by Michael addition to the enone system. Ab initio studies revealed that 2,4-substituted CPs are less prone to Michael additions, and as such were tested three families of those derivatives. We prepare the new CPs from furfural through a tandem furan ring opening/Nazarov electrocyclization and further functionalization. Experimentally the 2,4-substituted CPs exhibited no reactivity towards sulphur nucleophiles, while maintaining cytotoxicity against HT-29, MCF-7, NCI-H460, HCT-116 and MDA-MB 231 cells lines. Moreover, the selected CP are non-toxic against healthy HEK 293T cell lines and present proper calculated drug-like properties.

Design, synthesis, and evaluation of new anti-inflammatory natural products amide derivatives endowed with anti-blood cancer activity towards development of potential multifunctional agents against hematological cancers

New amide derivatives of the natural product 5,6,7-trimethoxyflavanone were designed as multifunctional antiproliferative molecules against blood cancer and the associated inflammatory conditions. The targeted compounds were synthesized efficiently in three linear steps employing known chalcone starting materials. Compounds 2h, 2i, 2l, 2t, 2v and 2x having bromo or nitro substituted-phenyl rings elicited potential inhibitory effects on macrophages production of nitric oxide, PGE₂ and TNF-α which are proinflammatory mediators involved in tumorigenesis and progression of blood cancer. Additionally, evaluation of direct inhibitory effects on the growth of diverse blood cancers including leukemia, lymphoma, and myeloma cell lines unveiled compound 2v as the most potential molecules eliciting at least five-folds the potency of the standard imatinib drug over the used diverse blood cancers. Furthermore, compound 2v showed good selectivity to blood cancer cells rather than normal MRC5 cells. Moreover, compound 2v triggered death of HL60 leukemia cells via apoptosis induction. In conclusion, the natural product-derived compound 2v might serve as a multifunctional lead compound for further development of agents for treatment of blood cancers.

Synthesis and Biological Evaluation of O6-Aminoalkyl-Hispidol Analogs as Multifunctional Monoamine Oxidase-B Inhibitors towards Management of Neurodegenerative Diseases

Oxidative catabolism of monoamine neurotransmitters by monoamine oxidases (MAOs) produces reactive oxygen species (ROS), which contributes to neuronal cells' death and also lowers monoamine neurotransmitter levels. In addition, acetylcholinesterase activity and neuroinflammation are involved in neurodegenerative diseases. Herein, we aim to achieve a multifunctional agent that inhibits the oxidative catabolism of monoamine neurotransmitters and, hence, the detrimental production of ROS while enhancing neurotransmitter levels. Such a multifunctional agent might also inhibit acetylcholinesterase and neuroinflammation. To meet this end goal, a series of aminoalkyl derivatives of analogs of the natural product hispidol were designed, synthesized, and evaluated against both monoamine oxidase-A (MAO-A) and monoamine oxidase-B (MAO-B). Promising MAO inhibitors were further checked for the inhibition of acetylcholinesterase and neuroinflammation. Among them, compounds 3aa and 3bc were identified as potential multifunctional molecules eliciting submicromolar selective MAO-B inhibition, low-micromolar AChE inhibition, and the inhibition of microglial PGE₂ production. An evaluation of their effects on memory and cognitive impairments using a passive avoidance test confirmed the in vivo activity of compound 3bc, which showed comparable activity to donepezil. In silico molecular docking provided insights into the MAO and acetylcholinesterase inhibitory activities of compounds 3aa and 3bc. These findings suggest compound 3bc as a potential lead for the further development of agents against neurodegenerative diseases.

Scaffold hopping of N-benzyl-3,4,5-trimethoxyaniline: 5,6,7-Trimethoxyflavan derivatives as novel potential anticancer agents modulating hippo signaling pathway

Scaffold hopping of N-benzyl-3,4,5-trimethoxyaniline afforded 5,6,7-trimethoxyflavan derivatives that were efficiently synthesized in four linear steps. As lung cancer is the most lethal cancer, twenty-three synthesized compounds were evaluated against a panel of lung cancer cells. Amongst, compounds 8q and 8e showed interesting activity. Hence, compounds 8q and 8e were evaluated against panels of diverse cancers. Compounds 8q and 8e showed broad spectrum anticancer activity. However, compound 8q was more effective and, hence, was advanced for potency evaluation and characterization. Compound 8q showed comparable potencies to gefitinib, and oxaliplatin against lung and colorectal cancers, respectively, and superior potencies to temozolomide, dacarbazine, cisplatin, enzalutamide, methotrexate, imatinib against brain, skin, ovary, prostate, breast, and blood cancers, respectively. Compound 8q increased cleaved PARP, caspase 3, and 7 inducing apoptosis. In addition, it inhibited cyclins A, B₁, H and cdc25c, and increased p53 triggering cell cycle arrest in G₂/M phase. Moreover, it decreased YAP and increased LATS1 and p-mob1/mob1 activating hippo signaling. Furthermore, it decreased p-PI3K/PI3k, p-mTOR/mTOR and p-P70S6K/P70S6K inhibiting PI3k pathway. Together, these findings present compound 8q as a potential anticancer lead compound for further development of potential agents.

Betulinic Acid-Brosimine B Hybrid Compound Has a Synergistic Effect with Imatinib in Chronic Myeloid Leukemia Cell Line, Modulating Apoptosis and Autophagy

Chronic myeloid leukemia (CML) is a myeloproliferative disease characterized by the formation of the BCR-ABL (breakpoint cluster region-Abelson) oncoprotein. As many patients display therapeutic resistance, the development of new drugs based on semisynthetic products represents a new potential therapeutic approach for treating the disease. In this study, we investigated the cytotoxic activity, possible mechanism of action of a hybrid compound of betulinic acid (BA) and brosimine B in CML cell lines that are sensitive (K-562) and resistant (K-562R) to imatinib, in addition to evaluating lower doses of imatinib in combination with the hybrid compound. The effects of the compound, and its combination with imatinib, on apoptosis, cell cycle, autophagy and oxidative stress were determined. The compound was cytotoxic in K-562 (23.57 ± 2.87 μM) and K-562R (25.80 ± 3.21 μM) cells, and a synergistic effect was observed when it was associated with imatinib. Apoptosis was mediated by the caspase 3 and 9 intrinsic pathway, and cell cycle evaluation showed arrest at G0/G1. In addition, the hybrid compound increased the production of reactive oxygen species and induced autophagy by increasing LC3II and Beclin-1 mRNA levels. Results suggest that this hybrid compound causes the death of both imatinib-sensitive and -resistant cell lines and may hold potential as a new anticancer treatment against CML.

Escaping ESKAPE resistance: in vitro and in silico studies of multifunctional carbamimidoyl-tethered indoles against antibiotic-resistant bacteria

Combining the hybridization and repurposing strategies, six compounds from our in-house library and having a designed hybrid structure of MBX-1162, pentamidine and MMV688271 were repurposed as potential antibacterial agents. Among, compounds 1a and 1d elicited potential sub-µg ml-1 activity against the high-priority antibiotic-resistant Gram-positive members of ESKAPE bacteria as well as antibiotic-susceptible Gram-positive bacteria. Furthermore, they showed potential low µg ml-1 activity against the explored critical-priority antibiotic-resistant Gram-negative members of ESKAPE bacteria. In time-kill assay, compound 1a has effective 0.5 and 0.25 µg ml-1 antibacterial lethal concentrations against MRSA in exponential growth phase. In silico investigations predicted compounds 1a and 1d as inhibitors of the open conformation of undecaprenyl diphosphate synthase involved in bacterial isoprenoid synthesis. In addition, compounds 1a and 1d were predicted as inhibitors of NADPH-free but not NADPH-bound form of ketol-acid reductoisomerase and may also serve as potential B-DNA minor groove binders with possible differences in the molecular sequence recognition. Overall, compounds 1a and 1d are presented as multifunctional potential antibacterial agents for further development against high- and critical-priority Gram-positive and Gram-negative antibiotic-resistant ESKAPE bacterial pathogens as well as antibiotic-susceptible Gram-positive bacterial pathogens.

Bestatin analogs-4-quinolinone hybrids as antileishmanial hits: Design, repurposing rational, synthesis, in vitro and in silico studies

Amongst different forms of leishmaniasis, visceral leishmaniasis caused by L. donovani is highly mortal. Identification of new hit compounds might afford new starting points to develop novel therapeutics. In this lieu, a rationally designed small library of bestatin analogs-4-quinolone hybrids were prepared and evaluated. Analysis of SAR unveiled distinct profiles for hybrids type 1 and type 2, which might arise from their different molecular targets. Amongst type 1 bestatin analog-4-quinolone hybrids, hybrid 1e was identified as potential hit inhibiting growth of L. donovani promastigotes by 91 and 53% at 50 and 25 μM concentrations, respectively. Meanwhile, hybrid 2j was identified amongst type 2 bestatin analog-4-quinolone hybrids as potential hit compound inhibiting growth of L. donovani promastigotes by 50 and 38% at 50 and 25 μM concentrations, respectively. Preliminary safety evaluation of the promising hit compounds showed that they are 50-100 folds safer against human derived monocytic THP-1 cells relative to the drug erufosine. In silico study was conducted to predict the possible binding of hybrid 1e with methionine aminopeptidases 1 and 2 of L. donovani. Molecular dynamic simulations verified the predicted binding modes and provide more in depth understanding of the impact of hybrid 1e on LdMetAP-1 and LdMetAP-2.

Improving Properties of Podophyllic Aldehyde-Derived Cyclolignans: Design, Synthesis and Evaluation of Novel Lignohydroquinones, Dual-Selective Hybrids against Colorectal Cancer Cells

New lignohydroquinone conjugates (L-HQs) were designed and synthesized using the hybridization strategy, and evaluated as cytotoxics against several cancer cell lines. The L-HQs were obtained from the natural product podophyllotoxin and some semisynthetic terpenylnaphthohydroquinones, prepared from natural terpenoids. Both entities of the conjugates were connected through different aliphatic or aromatic linkers. Among the evaluated hybrids, the L-HQ with the aromatic spacer clearly displayed the in vitro dual cytotoxic effect derived from each starting component, retaining the selectivity and showing a high cytotoxicity at short (24 h) and long (72 h) incubation times (4.12 and 0.0450 µM, respectively) against colorectal cancer cells. In addition, the cell cycle blockade observed by flow cytometry studies, molecular dynamics, and tubulin interaction studies demonstrated the interest of this kind of hybrids, which docked adequately into the colchicine binding site of tubulin despite their large size. These results prove the validity of the hybridization strategy and encourage further research on non-lactonic cyclolignans.

Design, synthesis and evaluation of 5-chloro-6-methylaurone derivatives as potential anti-cancer agents

A series of novel 5-chloro-6-methylaurone derivatives (6a-p) were synthesized and characterized by various spectroscopic techniques. The synthesized compounds were tested for anticancer activity against 60-human cancer cell line panel derived from nine cancer types at NCI, Bethesda, USA. Among the synthesized compounds, six compounds (6e, 6f, 6h, 6i, 6k and 6 m) exhibited growth inhibition and cytotoxic activity against various human cancer cell lines in one-dose data. The most potent compound among the series, 6i was active against 55 out of 60 human cancer cell lines. Compound 6i showed remarkable % growth inhibition and cytotoxicity against various cancer cell lines exhibiting % GI in the range 36.05-199.03. The compound 6i was further evaluated for five dose assay and exhibited GI50 1.90 µM and 2.70 µM against melanoma and breast cancer cell lines respectively. Further evaluation of 6i for five-dose assay exhibited a diverse spectrum of anti-cancer activity towards all the 60 human cancer cell line panel with the selectivity index ratio ranging 0.854-1.42  and 0.66-1.35  for GI50 and TGI respectively. Based on one-dose and five-dose data compound 6i was further evaluated for cell apoptosis against MDA-MB-468 breast cancer cell line and was found to induce early apoptosis in cells explaining its mode of action. The in-silico studies for the synthesized compounds as LSD1 inhibitors (2H94) have shown better docking score and binding energy comparable to vafidemstat. All the compounds followed Lipinski rule of five. These findings concluded that the compound 6i could lead to the development of a promising therapeutic anticancer agent.

Positional scanning of natural product hispidol's ring-B: discovery of highly selective human monoamine oxidase-B inhibitor analogues downregulating neuroinflammation for management of neurodegenerative diseases

Multifunctional molecules might offer better treatment of complex multifactorial neurological diseases. Monoaminergic pathways dysregulation and neuroinflammation are common convergence points in diverse neurodegenerative and neuropsychiatric disorders. Aiming to target these diseases, polypharmacological agents modulating both monoaminergic pathways and neuroinflammatory were addressed. A library of analogues of the natural product hispidol was prepared and evaluated for inhibition of monoamine oxidases (MAOs) isoforms. Several molecules emerged as selective potential MAO B inhibitors. The most promising compounds were further evaluated in vitro for their impact on microglia viability, induced production of proinflammatory mediators and MAO-B inhibition mechanism. Amongst tested compounds, 1p was a safe potent competitive reversible MAO-B inhibitor and inhibitor of microglial production of neuroinflammatory mediators; NO and PGE2. In-silico study provided insights into molecular basis of the observed selective MAO B inhibition. This study presents compound 1p as a promising lead compound for management of neurodegenerative disease.

Biologically synthesized black ginger-selenium nanoparticle induces apoptosis and autophagy of AGS gastric cancer cells by suppressing the PI3K/Akt/mTOR signaling pathway

BACKGROUND

Despite being a promising strategy, current chemotherapy for gastric cancer (GC) is limited due to adverse side effects and poor survival rates. Therefore, new drug-delivery platforms with good biocompatibility are needed. Recent studies have shown that nanoparticle-based drug delivery can be safe, eco-friendly, and nontoxic making them attractive candidates. Here, we develop a novel selenium-nanoparticle based drug-delivery agent for cancer treatment from plant extracts and selenium salts.

RESULTS

Selenium cations were reduced to selenium nanoparticles using Kaempferia parviflora (black ginger) root extract and named KP-SeNP. Transmission electron microscopy, selected area electron diffraction, X-ray diffraction, energy dispersive X-ray, dynamic light scattering, and Fourier-transform infrared spectrum were utilized to confirm the physicochemical features of the nanoparticles. The KP-SeNPs showed significant cytotoxicity in human gastric adenocarcinoma cell (AGS cells) but not in normal cells. We determined that the intracellular signaling pathway mechanisms associated with the anticancer effects of KP-SeNPs involve the upregulation of intrinsic apoptotic signaling markers, such as B-cell lymphoma 2, Bcl-associated X protein, and caspase 3 in AGS cells. KP-SeNPs also caused autophagy of AGS by increasing the autophagic flux-marker protein, LC3B-II, whilst inhibiting autophagic cargo protein, p62. Additionally, phosphorylation of PI3K/Akt/mTOR pathway markers and downstream targets was decreased in KP-SeNP-treated AGS cells. AGS-cell xenograft model results further validated our in vitro findings, showing that KP-SeNPs are biologically safe and exert anticancer effects via autophagy and apoptosis.

CONCLUSIONS

These results show that KP-SeNPs treatment of AGS cells induces apoptosis and autophagic cell death through the PI3K/Akt/mTOR pathway, suppressing GC progression. Thus, our research strongly suggests that KP-SeNPs could act as a novel potential therapeutic agent for GC.

Synthesis, biological evaluation and docking studies of methylene bearing cyanopyrimidine derivatives possessing a hydrazone moiety as potent Lysine specific demethylase-1 (LSD1) inhibitors: A promising anticancer agents

A series of novel cyanopyrimidine-hydrazone hybrids were synthesized and characterized with various spectroscopic techniques. The synthesized compounds were tested at NCI, USA, on a 60-cell line panel and most of the compounds showed remarkable cytotoxic activity against different cancer cell lines. Compound 5a was found to be the most potent compound of the series and it was further selected for five dose assays wherein it exhibited GI50 value of 0.414 µM and 0.417 µM against HOP-62 and OVCAR-4 cell lines respectively. The in-silico mechanistic studies indicated that these compounds are acting through inhibition of lysine specific demethylase 1 (LSD1) as evident from in to vitro LSD1 inhibition activity of compounds. Among various synthesized derivatives, compound 5a was found to have IC50-value of 0.956 µM. In addition, absorption, distribution, metabolism, excretion and toxicity profile (ADMET) was assessed for these novel derivatives to get an insight on their pharmacokinetic/dynamic attributes which revealed that synthesized compounds showed acceptable metabolic stability in human liver microsomes with minimal inhibition of cytochrome P450s (CYPs). The results indicated that compound 5a could be a promising lead compound for further development as a therapeutic agent for anticancer activity.

Exploring the Natural Compounds in Flavonoids for Their Potential Inhibition of Cancer Therapeutic Target MEK1 Using Computational Methods

The Mitogen-Activated Protein Kinase (MAPK) signaling pathway plays an important role in cancer cell proliferation and survival. MAPKs' protein kinases MEK1/2 serve as important targets in drug designing against cancer. The natural compounds' flavonoids are known for their anticancer activity. This study aims to explore flavonoids for their inhibition ability, targeting MEK1 using virtual screening, molecular docking, ADMET prediction, and molecular dynamics (MD) simulations. Flavonoids (n = 1289) were virtually screened using molecular docking and have revealed possible inhibitors of MEK1. The top five scoring flavonoids based on binding affinity (highest score for MEK1 is -10.8 kcal/mol) have been selected for further protein-ligand interaction analysis. Lipinski's rule (drug-likeness) and absorption, distribution, metabolism, excretion, and toxicity predictions were followed to find a good balance of potency. The selected flavonoids of MEK1 have been refined with 30 (ns) molecular dynamics (MD) simulation. The five selected flavonoids are strongly suggested to be promising potent inhibitors for drug development as anticancer therapeutics of the therapeutic target MEK1.

In Vitro Cytotoxicity and Apoptosis Inducing Evaluation of Novel Halogenated Isatin Derivatives

BACKGROUND

Isatin (1H-indole-2,3-dione) and its derivatives have been utilized in a variety of biological activities. Anticancer compounds were the most extensively highlighted and explored among the range of beneficial properties.

OBJECTIVE

Herein, we report the targeting effect of halogenated isatin derivatives on cancer cell mitochondria and their antiproliferative mechanism.

METHODS

A series of novel 5-halo-Isatin derivatives consisting of the 5-Amino-1,3,4-thiadiazole-2-thiol scaffold were synthesized and easily conducted in good yields through a condensation reaction between keto groups of Isatin and primary amine under alcoholic conditions, followed by S-benzylation. The compounds were fully characterized using spectroscopic methods such as 1H-NMR, FTIR, mass spectroscopy and then tested in vitro towards three cancer cell lines HT-29 (colon cancer), MCF-7 (breast cancer), and SKNMC (neuroblastoma). Apoptosis induction was investigated through assessment of caspase 3 and mitochondrial membrane potential.

RESULTS

The most potent compounds of 5b, 5r (IC50 = 18,13 μM), and 5n (IC50 = 20,17 μM) were found to show strong anticancer activity, especially for MCF7 cells. Further anticancer mechanism studies indicated that 5b and 5r induced apoptosis through the intrinsic mitochondrial pathway.

CONCLUSION

This research demonstrated that 5b and 5r have an anticancer property via the modulation of oxidative stress-mediated mitochondrial apoptosis and immune response, which deserves further studies on their clinical applications.

Effect of the dichloro-substitution on antiproliferative activity of phthalimide-thiazole derivatives. Rational design, synthesis, elastase, caspase 3/7, and EGFR tyrosine kinase activity and molecular modeling study

Phthalimide derivatives are a promising group of anticancer drugs, while aminothiazoles have great potential as elastase inhibitors. In these context fourteen phthalimido-thiazoles containing a dichloro-substituted phenyl ring with high antiproliferative activity against various cancer cell lines were designed and synthesized. Among the screened derivatives, compounds 5a-5e and 6a-6f showed high activity against human leukemia (MV4-11) cells with IC₅₀ values in the range of 5.56-16.10 µM. The phthalimide-thiazoles 5a, 5b and 5d showed the highest selectivity index (SI) relative to MV4-11 with 11.92, 10.80 and 8.21 values, respectively. The antiproliferative activity of compounds 5e, 5f and 6e, 6f against human lung carcinoma (A549) cells is also very high, with IC₅₀ values in the range of 6.69-10.41 µM. Lead compounds 6e and 6f showed elastase inhibition effect, with IC₅₀ values about 32 μM with mixed mechanism of action. The molecular modeling studies showed that the binding energies calculated for all set of compounds are strongly correlated with the experimentally determined values of IC₅₀. The lead compound 6e also increases almost 16 times caspase 3/7 activity in A549 cells compared to control. We have also demonstrated that compound 6f reduced EGFR tyrosine kinase levels in A549 cells by approximately 31%. These results clearly suggest that 3,4-dichloro-derivative 6e and 3,5-dichloro-derivative 6f could constitute lead dual-targeted anticancer drug candidates.

Therapeutic Potential of Natural Products in Treatment of Cervical Cancer: A Review

Cervical cancer is the fourth most common cancer among women worldwide. Though several natural products have been reported regarding their efficacies against cervical cancer, there has been no review article that categorized them according to their anti-cancer mechanisms. In this study, anti-cancerous natural products against cervical cancer were collected using Pubmed (including Medline) and google scholar, published within three years. Their mechanisms were categorized as induction of apoptosis, inhibition of angiogenesis, inhibition of metastasis, reduction of resistance, and regulation of miRNAs. A total of 64 natural products suppressed cervical cancer. Among them, Penicillium sclerotiorum extracts from Cassia fistula L., ethanol extracts from Bauhinia variegate candida, thymoquinone obtained from Nigella sativa, lipid-soluble extracts of Pinellia pedatisecta Schott., and 1'S-1'-acetoxychavicol extracted from Alpinia conchigera have been shown to have multi-effects against cervical cancer. In conclusion, natural products could be attractive candidates for novel anti-cancer drugs.

Resveratrol and other Stilbenes: Effects on Dysregulated Gene Expression in Cancers and Novel Delivery Systems

Trans-resveratrol (RESV), pterostilbene, trans-piceid and trans-viniferins are bioactive stilbenes present in grapes and other plants. Several groups applied biotechnology to introduce their synthesis in plant crops. Biochemical interaction with enzymes, regulation of non-coding RNAs, and activation of signaling pathways and transcription factors are among the main effects described in literature. However, solubility in ethanol, short half-life, metabolism by gut bacteria, make the concentration responsible for the effects observed in cultured cells difficult to achieve. Derivatives obtained by synthesis, trans-resveratrol analogs and methoxylated stilbenes show to be more stable and allow the synthesis of bioactive compounds with higher bioavailability. However, changes in chemical structure may require testing for toxicity. Thus, the delivery of RESV and its natural analogs incorporated into liposomes or nanoparticles, is the best choice to ensure stability during administration and appropriate absorption. The application of RESV and its derivatives with anti-inflammatory and anticancer activity is presented with description of novel clinical trials.

Reprofiling of pyrimidine-based DAPK1/CSF1R dual inhibitors: identification of 2,5-diamino-4-pyrimidinol derivatives as novel potential anticancer lead compounds

Hybridization of reported weakly active antiproliferative hit 5-amino-4-pyrimidinol derivative with 2-anilino-4-phenoxypyrimidines suggests a series of 2,5-diamino-4-pyrimidinol derivatives as potential antiproliferative agents. Few compounds belonging to the proposed series were reported as CSF1R/DAPK1 inhibitors as anti-tauopathies. However, the correlation between CSF1R/DAPK1 signalling pathways and cancer progression provides motives to reprofile them against cancer therapy. The compounds were synthesised, characterized, and evaluated against M-NFS-60 cells and a kinase panel which bolstered predictions of their antiproliferative activity and suggested the involvement of diverse molecular targets. Compound 6e, the most potent in the series, showed prominent broad-spectrum antiproliferative activity inhibiting the growth of hematological, NSCLC, colon, CNS, melanoma, ovarian, renal, prostate and breast cancers by 84.1, 52.79, 72.15, 66.34, 66.48, 51.55, 55.95, 61.85, and 60.87%, respectively. Additionally, it elicited an IC50 value of 1.97 µM against M-NFS-60 cells and good GIT absorption with Pe value of 19.0 ± 1.1 × 10-6 cm/s (PAMPA-GIT). Molecular docking study for 6e with CSF1R and DAPK1 was done to help to understand the binding mode with both kinases. Collectively, compound 6e could be a potential lead compound for further development of anticancer therapies.

Synthesis of Tamoxifen-Artemisinin and Estrogen-Artemisinin Hybrids Highly Potent Against Breast and Prostate Cancer

In the search for new and effective treatments of breast and prostate cancer, a series of hybrid compounds based on tamoxifen, estrogens, and artemisinin were successfully synthesized and analyzed for their in vitro activities against human prostate (PC-3) and breast cancer (MCF-7) cell lines. Most of the hybrid compounds exhibit a strong anticancer activity against both cancer cell lines - for example, EC50 (PC-3) down to 1.07 μM, and EC50 (MCF-7) down to 2.08 μM - thus showing higher activities than their parent compounds 4-hydroxytamoxifen (afimoxifene, 7; EC50 =75.1 (PC-3) and 19.3 μM (MCF-7)), dihydroartemisinin (2; EC50 =263.6 (PC-3) and 49.3 μM (MCF-7)), and artesunic acid (3; EC50 =195.1 (PC-3) and 32.0 μM (MCF-7)). The most potent compounds were the estrogen-artemisinin hybrids 27 and 28 (EC50 =1.18 and 1.07 μM, respectively) against prostate cancer, and hybrid 23 (EC50 =2.08 μM) against breast cancer. These findings demonstrate the high potential of hybridization of artemisinin and estrogens to further improve their anticancer activities and to produce synergistic effects between linked pharmacophores.

Design and synthesis of novel Flavone-based histone deacetylase inhibitors antagonizing activation of STAT3 in breast cancer

Histone deacetylases (HDACs) inhibitors have demonstrated a great clinical achievement in hematological malignancies. However, the efficacy of HDACs inhibitors in treating solid tumors remains limited due to the complicated tumor microenvironment. In this study, we designed and synthesized a class of novel HDACs inhibitors based on the structure of flavones and isoflavones, followed by biological evaluation. To be specific, a lead compound 15a was discovered with strong anti-proliferative effects on a variety of solid tumor cells, especially for breast cancer cells with resistance to SAHA. Studies demonstrated that 15a could significantly inhibit the activity of HDAC 1, 2, 3 (class I) and 6 (class IIB), leading to a dose-dependent accumulation of acetylated histones and α-Tubulin, cell cycle arrest (G1/S phase) and apoptosis in breast cancer cells. Furthermore, the lead compound 15a could also antagonize the activation of STAT3 induced by HDACs inhibition in some breast cancer cells, which further reduced the level of pro-survive proteins in tumor cells and enhanced anti-tumor activity regulated by STAT3 signaling in vivo. Overall, our findings demonstrated that the novel compound 15a might be a HDACs inhibitor candidate, which could be used as promising chemotherapeutic agent for breast cancer.

Anti-Breast Cancer Effect of 2-Dodecyl-6-Methoxycyclohexa-2,5-Diene-1,4-Dione in vivo and in vitro Through MAPK Signaling Pathway

Background

2-Dodecyl-6-methoxycyclohexa-2,5-diene-1,4-dione (DMDD) has been reported to inhibit a variety of cancer cell lines. The purpose of this study was to investigate the effects of DMDD on 4T1 breast cancer cells and the effects of DMDD on 4T1 breast cancer in mice and its molecular mechanisms.

Methods

4T1 breast cancer cells were treated with different concentrations of DMDD, and their proliferation, apoptosis, cell-cycle distribution, migration, and invasion were detected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT, Acridine orange and ethidium bromide dual staining analysis (AO/EB) dual staining, flow cytometry, scratch test, and the Transwell assay. Relative quantitative real-time qPCR analysis and Western blot were applied to examine the expression levels of related genes and proteins. In animal experiments, we established a xenograft model to assess the anti-breast cancer effects of DMDD by evaluating the inhibition rate. The apoptotic activity of DMDD was evaluated by hematoxylin-eosin (HE) staining, transmission electron microscope (TEM) analysis and TdT-mediated dUTP nick end labeling (TUNEL) assays. The mRNA expression levels of MAPK pathway components were detected by relative quantitative real-time qPCR. In addition, the protein expression levels of MAPK pathway components were assessed through immunohistochemical assays and Western blotting.

Results

Experiments showed that DMDD could inhibit the proliferation, migration, invasion of 4T1 cells and induce cellular apoptosis and G1 cell cycle arrest. Moreover, DMDD down-regulated the mRNA expressions of raf1, mek1, mek2, erk1, erk2, bcl2, and up-regulated the mRNA expression of bax. DMDD reduced the protein expressions of p-raf1, p-mek, p-erk, p-p38, Bcl2, MMP2, MMP9 and increased the protein expressions of Bax and p-JNK. The results showed that DMDD can effectively reduce the tumor volume and weight of breast cancer in vivo, up-regulate the expression of IL-2, down-regulate the expression of IL-4 and IL-10, induce the apoptosis of breast cancer cells in mice, and regulate the expression of genes and proteins of the MAPK pathway.

Conclusion

Our study indicates that DMDD can inhibit proliferation, migration, and invasion and induces apoptosis and cell-cycle arrest of 4T1 breast cancer cells. Also, our findings indicate that DMDD induces the apoptosis of breast cancer cells and inhibits the growth in mice. Its mechanism may be related to the MAPK pathway.

Resveratrol - A comprehensive review of recent advances in anticancer drug design and development

Resveratrol is a natural polyphenolic stilbene isolated from various plants, foods and beverages with a broad spectrum of biological and pharmacological properties through modulating diverse targets and signaling pathways. Particularly, it has attracted a great deal of attention as a promising and multitarget anticancer agent due to its potential use in chemoprevention and chemotherapy of various tumors. However, unfavorable pharmacokinetics/pharmacodynamics profile such as poor bioavailability restricted its applications. Therefore, medicinal chemists have synthesized a lot of novel derivatives and analogues of resveratrol using different modification strategies to overcome these limitations and improve anticancer efficacy. Herein, we reviewed the design, synthesis, structure-activity relationship and mechanism of the most potent and privileged resveratrol-based compounds that showed promising anticancer activities in the last five years. We classified these compounds into the ten different categories based on their chemical structure similarities.

Thiazolidine-2,4-dione-based irreversible allosteric IKK-β kinase inhibitors: Optimization into in vivo active anti-inflammatory agents

Selective kinase inhibitors development is a cumbersome task because of ATP binding sites similarities across kinases. On contrast, irreversible allosteric covalent inhibition offers opportunity to develop novel selective kinase inhibitors. Previously, we reported thiazolidine-2,4-dione lead compounds eliciting in vitro irreversible allosteric inhibition of IKK-β. Herein, we address optimization into in vivo active anti-inflammatory agents. We successfully developed potent IKK-β inhibitors with the most potent compound eliciting IC₅₀ = 0.20 μM. Cellular assay of a set of active compounds using bacterial endotoxin lipopolysaccharide (LPS)-stimulated macrophages elucidated significant in vitro anti-inflammatory activity. In vitro evaluation of microsomal and plasma stabilities showed that the promising compound 7a is more stable than compound 7p. Finally, in vivo evaluation of 7a, which has been conducted in a model of LPS-induced septic shock in mice, showed its ability to protect mice against septic shock induced mortality. Accordingly, this study presents compound 7a as a novel potential irreversible allosteric covalent inhibitor of IKK-β with verified in vitro and in vivo anti-inflammatory activity.

The Anti-Proliferative Activity of the Hybrid TMS-TMF-4f Compound Against Human Cervical Cancer Involves Apoptosis Mediated by STAT3 Inactivation

We previously reported the potential anti-proliferative activity of 3-(5,6,7-trimethoxy-4-oxo-4H-chromen-2-yl)-N-(3,4,5-trimethoxyphenyl) benzamide (TMS-TMF-4f) against human cancer cells; however, the underlying molecular mechanisms have not been investigated. In the present study, TMS-TMF-4f showed the highest cytotoxicity in human cervical cancer cells (HeLa and CaSki) and low cytotoxicity in normal ovarian epithelial cells. Annexin V-FITC and propidium iodide (PI) double staining revealed that TMS-TMF-4f-induced cytotoxicity was caused by the induction of apoptosis in both HeLa and CaSki cervical cancer cells. The compound TMS-TMF-4f enhanced the activation of caspase-3, caspase-8, and caspase-9 and regulated Bcl-2 family proteins, which led to mitochondrial membrane potential (MMP) loss and resulted in the release of cytochrome c and Smac/DIABLO into the cytosol. Also, TMS-TMF-4f suppressed both constitutive and IL-6-inducible levels of phosphorylated STAT3 (p-STAT3) and associated proteins such as Mcl-1, cyclin D1, survivin, and c-Myc in both cervical cancer cells. STAT-3 overexpression completely ameliorated TMS-TMF-4f-induced apoptotic cell death and PARP cleavage. Docking analysis revealed that TMS-TMF-4f could bind to unphosphorylated STAT3 and inhibit its interconversion to the activated form. Notably, intraperitoneal administration of TMS-TMF-4f (5, 10, or 20 mg/kg) decreased tumor growth in a xenograft cervical cancer mouse model, demonstrated by the increase in TUNEL staining and PARP cleavage and the reduction in p-STAT3, Mcl-1, cyclin D1, survivin, and c-Myc expression levels in tumor tissues. Taken together, our results suggest that TMS-TMF-4f may potentially inhibit human cervical tumor growth through the induction of apoptosis via STAT3 suppression.

Coix lacryma-jobi var. ma-yuen Stapf sprout extract induces cell cycle arrest and apoptosis in human cervical carcinoma cells

Background

Cervical cancer is the second-leading cause of cancer-related mortality in females. Coix lacryma-jobi L. var. ma-yuen (Rom.Caill.) Stapf ex Hook. f. is the most widely recognized medicinal herb for its remedial effects against inflammation, endocrine system dysfunctions, warts, chapped skin, rheumatism, and neuralgia and is also a nourishing food.

Methods

To investigate the activity of Coix lacryma-jobi sprout extract (CLSE) on cell proliferation in human cervical cancer HeLa cells, we conducted a Cell Counting Kit-8 (CCK-8) assay. Flow-cytometric analysis and western blot analysis were performed to verify the effect of CLSE on the regulation of the cell cycle and apoptosis in HeLa cells.

Results

We observed that CLSE significantly inhibited cell proliferation. Furthermore, CLSE dose-dependently promoted cell cycle arrest at the sub-G1/ S phase in HeLa cells, as detected by bromodeoxyuridine (BrdU) staining. The cell-cycle-arrest effects of CLSE in HeLa cells were associated with downregulation of cyclin D1 and cyclin-dependent kinases (CDKs) 2, 4, and 6. Moreover, CLSE induced apoptosis, as determined by flow-cytometric analysis and nuclear DNA fragmentation with Annexin V/propidium iodide (PI) and 4′6′-diamidino-2-phenylindole (DAPI) staining. Induction of apoptosis by CLSE was involved in inhibition of the antiapoptotic protein B-cell lymphoma 2 (Bcl-2) and upregulation of the apoptotic proteins p53, cleaved poly (ADP-ribose) polymerase (PARP), cleaved caspase-3, and cleaved caspase-8. Finally, we observed that CLSE inactivated the phosphoinositide 3-kinase (PI3K) and protein kinase B (AKT) pathways.

Conclusions

CLSE causes cell cycle arrest and apoptotic cell death through inactivation of the PI3K/AKT pathway in HeLa cells, suggesting it is a viable therapeutic agent for cervical cancer owing to its anticancer effects.

Optimization study towards more potent thiazolidine-2,4-dione IKK-β modulator: Synthesis, biological evaluation and in silico docking simulation

Inhibition of IKK-β (inhibitor of nuclear factor kappa-B kinase subunit beta) has been broadly documentedas a promising approach for treatment of acute and chronic inflammatory diseases, cancer, and autoimmune diseases. Recently, we have identified a novel class of thiazolidine-2,4-diones as structurally novel modulators for IKK-β. Herein, we report a hit optimization study via analog synthesis strategy aiming to acquire more potent derivative(s), probe the structure activity relationship (SAR), and get reasonable explanations for the elicited IKK-β inhibitory activities though an in silico docking simulation study. Accordingly, a new series of eighteen thiazolidine-2,4-dione derivatives was rationally designed, synthesized, identified with different spectroscopic techniques and biologically evaluated as noteworthy IKK-β potential modulators. Successfully, new IKK-β potent modulators were obtained, including the most potent analog up-to-date 7m with IC₅₀ value of 260 nM. A detailed structure activity relationship (SAR) was discussed and a mechanistic study for 7m was carried out indicating its irreversible inhibition mode with IKK-β (K_inact value = 0.01 (min^-1). Furthermore, the conducted in silico simulation study provided new insights for the binding modes of this novel class of modulators with IKK-β.

Investigating the Anticancer Activity of Isatin/Dihydropyrazole Hybrids

A series of isatin-dihydropyrazole hybrids have been synthesized in order to assess their potential as anticancer agents. In particular, 12 compounds were evaluated for their antiproliferative activity toward A549, IGR39, U87, MDA-MB-231, MCF-7, BT474, BxPC-3, SKOV-3, and H1299 cell lines, and human foreskin fibroblasts. Four compounds exhibited interesting antiproliferative activity and were further examined to determine their EC₅₀ values toward a panel of selected tumor cell lines. The best compounds were then investigated for their induced mechanism of cell death. Preliminary structure-activity relationship indicates that the presence of a substituent such as a chlorine atom or a methyl moiety in position 5 of the isatin nucleus is beneficial for the antitumor activity. EMAC4001 proved the most promising compound within the studied series with EC₅₀ values ranging from 0.01 to 0.38 μM.

Dicerandrol B: a natural xanthone dimer induces apoptosis in cervical cancer HeLa cells through the endoplasmic reticulum stress and mitochondrial damage

Background

Dicerandrol B is a natural antitumor agent that can be isolated from the endophytic fungus, Phomopsis sp. The present study investigated the effects of dicerandrol B on human cervical cancer HeLa cells.

Materials and methods

In this study, dicerandrol B was identified by electrospray ionization mass spectrometry and nuclear magnetic resonance spectroscopy. We used MTT to detect the cell viability. Flow cytometry was used to analyze the apoptosis and cell cycle. Western blot was used to examine the expression of related proteins.

Results

Dicerandrol B was isolated from the endophytic fungus Phomopsis sp. The MTT assay and flow cytometry showed that dicerandrol B significantly inhibited HeLa cell viability and induced G2/M cell cycle arrest. Western blot analysis demonstrated that dicerandrol B increased the levels of GRP78, ubiquitin, cleaved PARP, and Bax protein, decreased the levels of PARP and Bcl-2 protein, and caused an increase in the Bax/Bcl-2 ratio in HeLa cells. Dicerandrol B increased the production of ROS in HeLa cells, which was attenuated by the antioxidant N-acetyl-l-cysteine.

Conclusion

These findings suggest that dicerandrol B induces apoptosis in human HeLa cells, possibly through the endoplasmic reticulum stress and mitochondrial apoptotic pathways. This suggests that dicerandrol B possesses strong anticancer activity in cervical cancer and provides insight into the underlying mechanisms.

Resveratrol analog, N-(4-methoxyphenyl)-3,5-dimethoxybenzamide induces G2/M phase cell cycle arrest and apoptosis in HeLa human cervical cancer cells

In this study, several resveratrol analogs were synthesized and evaluated in search of a more effective anti-proliferative resveratrol analog. Among the evaluated resveratrol analogs, we have identified N-(4-methoxyphenyl)-3,5-dimethoxybenamide (MPDB) as a potent anti-proliferative compound. Treatment with MPDB resulted in G₂/M phase cell cycle arrest, which was accompanied by alteration of G₂/M-related protein expression and phosphorylation. MPDB-induced G₂/M arrest was blocked by transfection of ATM/ATR siRNAs, indicating the critical role of ATM/ATR in G₂/M phase arrest. In addition, treatment with MPDB displayed the activation of caspase and decreased Bcl-xl protein expression after 20 h in HeLa cells. Moreover, MPDB increased cytosolic cytochrome c release and Fas and Fas-L protein expression, indicating intrinsic and extrinsic apoptosis pathway, respectively. These results suggest that MPDB is a new and potent compound that induces ATM/ATR-dependent G₂/M phase cell cycle arrest and apoptosis, implicating it as a putative candidate in the investment of cervical cancer therapy.