Chalcone Scaffold in Anticancer Armamentarium: A Molecular Insight

Design, synthesis, and biological evaluation of chalcone acetamide derivatives against triple negative breast cancer

Chalcones are chemical scaffolds found in natural products, particularly in plants, and are considered for structural diversity in medicinal chemistry for drug development. Herein, we designed and synthesised novel acetamide derivatives of chalcone, characterizing them using 1H NMR, 13C NMR, HRMS, and IR spectroscopic methods. These derivatives were then screened against human cancer cells for cytotoxicity using the SRB assay. Among the tested derivatives, 7g, with a pyrrolidine group, exhibited better cell growth inhibition activity against triple-negative breast cancer (TNBC) cells. Further assays, including SRB, colony formation, and fluorescent dye-based microscopic analysis, confirmed that 7g significantly inhibited MDA-MB-231 cell proliferation. Furthermore, 7g promoted apoptosis by upregulating cellular reactive oxygen species (ROS) levels and disrupting mitochondrial membrane potential (MMP). Elevated expression of pro-apoptotic proteins (Bax and caspase-3) and a higher Bax/Bcl-2 ratio with downregulation of anti-apoptotic (Bcl-2) protein levels were observed in TNBC cells. The above results suggest that 7g can promote cellular death through apoptotic mechanisms in TNBC cells.

The effect of novel nitrogen-based chalcone analogs on colorectal cancer cells: Insight into the molecular pathways

In colorectal cancer (CRC), aberrations in KRAS are associated with aggressive tumorigenesis and an overall low survival rate because of chemoresistance and adverse effects. Ergo, complementary, and integrative medicines are being considered for CRC treatment. Among which is the use of natural chalcones that are known to exhibit anti-tumor activities in KRAS mutant CRC subtypes treatment regimens. Consequently, we examine the effect of two novel compounds (DK13 and DK14) having chalcones with nitrogen mustard moiety on CRC cell lines (HCT-116 and LoVo) with KRAS mutation. These compounds were synthesized in our lab and previously reported to exhibit potent activity against breast cancer cells. Our data revealed that DK13 and DK14 treatment suppress cell growth, disturb the progression of cell cycle, and trigger apoptosis in CRC cell lines. Besides, treatment with both compounds impedes cell invasion and colony formation in both cell lines as compared to 5-FU; this is accompanied by up and down regulations of E-cadherin and Vimentin, respectively. At the molecular level, both compounds deregulate the expression and phosphorylation of β-catenin, Akt and mTOR, which are the main likely molecular mechanisms underlying these biological occurrences. Our findings present DK13 and DK14 as novel chemotherapies against CRC, through β-catenin/Akt/mTOR signaling pathways.

Finding a Novel Chalcone-Cinnamic Acid Chimeric Compound with Antiproliferative Activity against MCF-7 Cell Line Using a Free-Wilson Type Approach

In this work, we carried out the design and synthesis of new chimeric compounds from the natural cytotoxic chalcone 2',4'-dihydroxychalcone (2',4'-DHC, A) in combination with cinnamic acids. For this purpose, a descriptive and predictive quantitative structure-activity relationship (QSAR) model was developed to study the chimeric compounds' anti-cancer activities against human breast cancer MCF-7, relying on the presence or absence of structural motifs in the chalcone structure, like in a Free-Wilson approach. For this, we used 207 chalcone derivatives with a great variety of structural modifications over the α and β rings, such as halogens (F, Cl, and Br), heterocyclic rings (piperazine, piperidine, pyridine, etc.), and hydroxyl and methoxy groups. The multilinear equation was obtained by the genetic algorithm technique, using logIC₅₀ as a dependent variable and molecular descriptors (constitutional, topological, functional group count, atom-centered fragments, and molecular properties) as independent variables, with acceptable statistical parameter values (R2 = 86.93, Q2_LMO = 82.578, Q2_BOOT = 80.436, and Q2_EXT = 80.226), which supports the predictive ability of the model. Considering the aromatic and planar nature of the chalcone and cinnamic acid cores, a structural-specific QSAR model was developed by incorporating geometrical descriptors into the previous general QSAR model, again, with acceptable parameters (R2 = 85.554, Q2_LMO = 80.534, Q2_BOOT = 78.186, and Q2_EXT = 79.41). Employing this new QSAR model over the natural parent chalcone 2',4'-DHC (A) and the chimeric compound 2'-hydroxy,4'-cinnamate chalcone (B), the predicted cytotoxic activity was achieved with values of 55.95 and 17.86 µM, respectively. Therefore, to corroborate the predicted cytotoxic activity compounds A and B were synthesized by two- and three-step reactions. The structures were confirmed by ¹H and ¹³C NMR and ESI+MS analysis and further evaluated in vitro against HepG2, Hep3B (liver), A-549 (lung), MCF-7 (breast), and CasKi (cervical) human cancer cell lines. The results showed IC₅₀ values of 11.89, 10.27, 56.75, 14.86, and 29.72 µM, respectively, for the chimeric cinnamate chalcone B. Finally, we employed B as a molecular scaffold for the generation of cinnamate candidates (C-K), which incorporated structural motifs that enhance the cytotoxic activity (pyridine ring, halogens, and methoxy groups) according to our QSAR model. ADME/tox in silico analysis showed that the synthesized compounds A and B, as well as the proposed chalcones C and G, are the best candidates with adequate drug-likeness properties. From all these results, we propose B (as a molecular scaffold) and our two QSAR models as reliable tools for the generation of anti-cancer compounds over the MCF-7 cell line.

The Degree of Hydroxylation of Phenolic Rings Determines the Ability of Flavonoids and Stilbenes to Inhibit Calcium-Mediated Membrane Fusion

This paper discusses the possibility of using plant polyphenols as viral fusion inhibitors with a lipid-mediated mechanism of action. The studied agents are promising candidates for the role of antiviral compounds due to their high lipophilicity, low toxicity, bioavailability, and relative cheapness. Fluorimetry of calcein release at the calcium-mediated fusion of liposomes, composed of a ternary mixture of dioleoyl phosphatidylcholine, dioleoyl phosphatidylglycerol, and cholesterol, in the presence of 4'-hydroxychalcone, cardamonin, isoliquiritigenin, phloretin, resveratrol, piceatannol, daidzein, biochanin A, genistein, genistin, liquiritigenin, naringenin, catechin, taxifolin, and honokiol, was performed. It was found that piceatannol significantly inhibited the calcium-induced fusion of negatively charged vesicles, while taxifolin and catechin showed medium and low antifusogenic activity, respectively. As a rule, polyphenols containing at least two OH-groups in both phenolic rings were able to inhibit the calcium-mediated fusion of liposomes. In addition, there was a correlation between the ability of the tested compounds to inhibit vesicle fusions and to perturb lipid packing. We suggest that the antifusogenic action of polyphenols was determined by the depth of immersion and the orientation of the molecules in the membrane.

Discovery of a chalcone derivative as potent necroptosis inhibitor for the treatment of acute kidney injury

Necroptosis, a form of inflammation-related programmed cell death, is a major mechanism of proximal tubular cell injury in acute kidney injury (AKI). Blockade of necroptosis signaling represents a promising strategy for clinical therapy of AKI. Previously, we identified a small molecular RIPK1 inhibitor Cpd-71 with nephroprotective activities. In order to discover more nephroprotective agents, in this study, twenty chalcone derivatives were synthesized and evaluated for their anti-necroptosis and nephroprotective activities. Among the chalcone derivatives, Cpd-2 exhibited the most potent anti-necroptosis activity (IC₅₀ = 1.08 μM) and protective activity (EC₅₀ = 1.49 μM) through directly binding to RIPK1 and blocking RIPK1-RIPK3-MLKL signaling pathway. Furthermore, Cpd-2 effectively attenuated cisplatin or hypoxia/reoxygenation (H/R)-induced injury and necroptotic inflammation in renal cell models. Moreover, in cisplatin- or ischemia/reperfusion (I/R) induced AKI mouse model, detection of creatinine and urea nitrogen in blood showed that Cpd-2 improved kidney function. PAS staining and immunofluorescence analysis indicated that Cpd-2 also reduced pathological damage and inhibited inflammatory development in kidney tissues. In summary, although some chalcone derivatives have been reported to prevent kidney injury previously, our present study not only discovered a promising leading compound Cpd-2, but also provided a novel and successful practice for the development of necroptosis inhibitors from natural products derivatives as AKI therapeutic agents. This article is protected by copyright. All rights reserved.

New 1,2,3-triazole linked ciprofloxacin-chalcones induce DNA damage by inhibiting human topoisomerase I& II and tubulin polymerization

A series of novel 1,2,3-triazole-linked ciprofloxacin-chalcones 4a-j were synthesised as potential anticancer agents. Hybrids 4a-j exhibited remarkable anti-proliferative activity against colon cancer cells. Compounds 4a-j displayed IC₅₀s ranged from 2.53-8.67 µM, 8.67-62.47 µM, and 4.19-24.37 µM for HCT116, HT29, and Caco-2 cells; respectively, whereas the doxorubicin, showed IC₅₀ values of 1.22, 0.88, and 4.15 µM. Compounds 4a, 4b, 4e, 4i, and 4j were the most potent against HCT116 with IC₅₀ values of 3.57, 4.81, 4.32, 4.87, and 2.53 µM, respectively, compared to doxorubicin (IC₅₀ = 1.22 µM). Also, hybrids 4a, 4b, 4e, 4i, and 4j exhibited remarkable inhibitory activities against topoisomerase I, II, and tubulin polymerisation. They increased the protein expression level of γH2AX, indicating DNA damage, and arrested HCT116 in G2/M phase, possibly through the ATR/CHK1/Cdc25C pathway. Thus, the novel ciprofloxacin hybrids could be exploited as potential leads for further investigation as novel anticancer medicines to fight colorectal carcinoma.

Antitumor Effect of the Synthesized Chalcone Analogues on HeLa Cell Line

Chalcones represent a type of flavonoids which are located at vegetative and reproductive organs of plants and they can be metabolic progenitor molecules for several flavonoids and isoflavonoids. Many studies indicated that molecular structure of chalcone accountable for their anti-tumor, anti-inflammatory and anti-oxidant effects. The aim of our research was to investigate anti-tumor effect and mechanism of action of three synthesized chalcone analogues on HeLa cells. The anti-tumor effectiveness of chalcone analogues was compared to effects of the dehydrozingerone and cisplatin that were used as referent substances.

The viability of the treated cells was evaluated using MTT assay. Evaluation of cell death was determined by flow cytometry and cells were stained with Annexin V-FITC/7-AAD. The result of our research indicated that used chalcones have stronger antitumor effect relative to the dehydrozingerone and cisplatin.

The IC50 values of the chalcones ranged between 1.69-6.18 μM, with CH1 being more cytotoxic after 24 h of treatment, while CH3 being more cytotoxic after 48 h of treatment on HeLa cells. All investigated chalcones induced apoptosis in HeLa cells via mitochondrial pathway, which was detected expression Bax and Bcl- 2 proteins.

Our results provided evidence that chalcones induced apoptosis in HeLa cervical carcinoma through the intrinsic apoptotic pathway. These findings provide insights into the molecular mechanism of chalcones-induced cell death.

Identification of novel furo[2,3-d]pyrimidine based chalcones as potent anti-breast cancer agents: synthesis, in vitro and in vivo biological evaluation

Various substituted synthetic chalcones demonstrated potent anti-cancer activities. In the current study a series of novel furo[2,3-d]pyrimidine based chalcones were synthesized as potential anticancer agents. Among the different substituted derivatives, two of the halogen bearing chalcones, 5d and 5e, demonstrated potent anti-proliferative activity against an NCI 59 cell line, with mean GI₅₀ values of 2.41 μM and 1.23 μM, respectively. Moreover, both compounds showed pronounced cytotoxic activity (5d; 1.20 ± 0.21, 5e; 1.90 ± 0.32) against the resistant MCF-7 cell line when compared to doxorubicin; 3.30 ± 0.18. Such outcomes provoked the initiation of an in vivo anticancer assessment study, where compound 5e revealed comparable results to doxorubicin.

Chalcones against the hallmarks of cancer: a mini-review

Chalcones (1,3-diphenylpropen-1-ones) are a class of flavonoids that have been shown a broad spectrum of biological activities with therapeutic potential. Naturally occurring chalcones or synthetic chalcone derivatives have been extensively investigated as anticancer compounds. Cancer is still among the leading causes of death globally, although cancer treatments have improved over the past decades. Most of chemotherapeutic drugs target proliferating tumor cells; however, the cancer cells capabilities are also associated to tumor surround microenvironment. Thereby, the search of new compounds with a broad antitumor activity is still a great challenge. The cytotoxicity mechanisms of chalcones are beyond apoptosis induction in tumor cells, which make them promising compound for cancer therapy. In this mini-review we summarized recent studies that describe the anticancer potential of chalcones related to some of hallmarks of cancer. We shed a light on sustaining proliferative signaling, tumor-promoting inflammation, activating invasion and metastasis, inducing angiogenesis and resisting cell death.

Anticancer Activity of Natural and Synthetic Chalcones

Cancer is a condition caused by many mechanisms (genetic, immune, oxidation, and inflammatory). Anticancer therapy aims to destroy or stop the growth of cancer cells. Resistance to treatment is theleading cause of the inefficiency of current standard therapies. Targeted therapies are the most effective due to the low number of side effects and low resistance. Among the small molecule natural compounds, flavonoids are of particular interest for theidentification of new anticancer agents. Chalcones are precursors to all flavonoids and have many biological activities. The anticancer activity of chalcones is due to the ability of these compounds to act on many targets. Natural chalcones, such as licochalcones, xanthohumol (XN), panduretin (PA), and loncocarpine, have been extensively studied and modulated. Modification of the basic structure of chalcones in order to obtain compounds with superior cytotoxic properties has been performed by modulating the aromatic residues, replacing aromatic residues with heterocycles, and obtaining hybrid molecules. A huge number of chalcone derivatives with residues such as diaryl ether, sulfonamide, and amine have been obtained, their presence being favorable for anticancer activity. Modification of the amino group in the structure of aminochalconesis always favorable for antitumor activity. This is why hybrid molecules of chalcones with different nitrogen hetercycles in the molecule have been obtained. From these, azoles (imidazole, oxazoles, tetrazoles, thiazoles, 1,2,3-triazoles, and 1,2,4-triazoles) are of particular importance for the identification of new anticancer agents.

Flavonoid-Based Cancer Therapy: An Updated Review

As cancers are one of the most important causes of human morbidity and mortality worldwide, researchers try to discover novel compounds and therapeutic approaches to decrease survival of cancer cells, angiogenesis, proliferation and metastasis. In the last decade, use of special phytochemical compounds and flavonoids was reported to be an interesting and hopeful tactic in the field of cancer therapy. Flavonoids are natural polyphenols found in plant, fruits, vegetables, teas and medicinal herbs. Based on reports, over 10,000 flavonoids have been detected and categorized into several subclasses, including flavonols, anthocyanins, flavanones, flavones, isoflavones and chalcones. It seems that the anticancer effect of flavonoids is mainly due to their antioxidant and anti inflammatory activities and their potential to modulate molecular targets and signaling pathways involved in cell survival, proliferation, differentiation, migration, angiogenesis and hormone activities. The main aim of this review is to evaluate the relationship between flavonoids consumption and cancer risk, and discuss the anti-cancer effects of these natural compounds in human cancer cells. Hence, we tried to collect and revise important recent in vivo and in vitro researches about the most effective flavonoids and their main mechanisms of action in various types of cancer cells.

Synthesis, cytotoxicity and in silico study of some novel benzocoumarin-chalcone-bearing aryl ester derivatives and benzocoumarin-derived arylamide analogs

The development of new prostate cancer protein receptor cytochrome P450 17A1 inhibitors offers the possibility of generating structures of increased potency. To this end, the chalcone analogs 7 and 8 were prepared from treatment of methyl 3-oxo-3H-benzocoumarin-2-carboxylate (4) with aryl aldehydes. Treatment of 7 and 8 with three anti-inflammatory drugs, flurbiprofen, ketoprofen and ibuprofen, in the presence of POCl3/DMAP gave the ester analogs 9–12. Analogously, treatment of ethyl 3-oxo-3H-benzocoumarin-2-carboxylate (15), prepared previously from 2-hydroxy-1-naphthaldehyde (13) and dimethylmalonate (14), with various arylamines: 4-bromoaniline, 2-amino-6-methylpyridine, amino-antipyrine and 2-amino-5-nitrothiazole, in the presence of potassium tert-butoxide gave the benzocoumarine-3-arylamide analogs. The in vitro cytotoxic activities of 9–12 and 16–19 were evaluated against human prostate cancer cell lines (PC-3) and normal human liver epithelia (WRL-68) by MTT assay. Compounds 10 and 17 were the most active cytotoxic agents among the series against PC-3 cells with IC50 values of 71.35 and 78.25 μg mL–1 with SI values of 3.0 and 4.2, respectively (calculated from the cytotoxicity effects of 10 and 17 on the normal human liver epithelia [WRL-68]). Furthermore, compounds 11 and 12 were tested against breast cancer (HER2 cell lines), prostate cancer (DU-135 cell lines) and MCF-7 but were inactive. Molecular docking studies between the protein receptor CYPP450 17A1 and compounds 10 and 17 revealed that these compounds primarily form hydrophobic interactions with the receptor.

Study on the Interaction of 4'-Hydroxychalcones and their Mannich Derivatives with Calf Thymus DNA by TLC and Spectroscopic Methods, a DNA Cleavage Study

Background:

Phenolic Mannich bases derived from hydroxychalcones show remarkable cytotoxic potencies towards cancer cell lines. However, the exact mechanism of action is still partially uncleared.

Objective:

Interaction of two hydroxychalcones and their Mannich derivatives with calf thymus DNA (ctDNA) has been investigated.

Methods:

Thin-layer chromatography and UV-Vis spectroscopic method were used for studying the interaction. The binding constant has been determined by UV-Vis spectrophotometric titration. The DNA cleavage activity of the compounds was studied by agarose gel electrophoresis.

Results:

Interaction of the compounds with ctDNA exhibited relatively high intrinsic binding constant (4-5x104 M-1). The results indicate existence of weak, non-covalent interactions between the investigated derivatives with ctDNA. Some compounds showed a slight DNA cleavage activity with pBR322.

Conclusion:

The obtained results provide additional knowledge on the previously documented cytotoxicity against tumor cell lines of the hydroxychalcones and their Mannich-derivatives.

Molecular Docking of 4-ethoxychalcones on Oxidoreductase/Pirin Inhibitors and Cytotoxic Evaluation on Breast/Skin Cancer Cell Lines

Background:

The role of α, β unsaturated propenone derivatives, has attracted the chemists for its biological importance. An attempt is made to reveal the interaction between breast and skin cancer cell lines with the help of molecular docking studies.

Objective:

The study aimed to synthesize and characterize 4-ethoxychalcones for testing breast and skin cancer targets.

Methods:

A series of chalcone analogues starting from 4-ethoxyacetophenone and substituted aromatic aldehydes were synthesized, well-characterized and evaluated for their in vitro anticancer activities against human breast cancer (MDA-MB-231) and human metastatic melanoma (A-375) cell lines by MTT assay. Docking simulation was performed to study the drug-receptor interaction of chalcone scaffold on the active site of target inhibitor bound to cytochrome P450 family oxidoreductase for breast cancer and Pirin inhibiting target for skin cancer, respectively.

Results and Discussion:

After performing cytotoxic evaluation, it was observed that compounds having a substitution at the para position showed better results compared to ortho and meta positions for both the cell lines. Molecular docking studies revealed different types of interactions with selected oxidoreductase and Pirin inhibiting targets. Ligand-protein interactions and morphological changes are monitored by molecular dynamics.

Conclusion:

The presence of electron-withdrawing and donating groups on ring B marginally affected IC50 and docking scores. The stability of the binding mode of ligands having high inhibitory efficiency for compounds 8 and 10 predicted by docking studies was confirmed by molecular dynamics simulation. The pharmacokinetic parameters were found to be within the acceptable range. Further molecular dynamics study would provide the necessary information.

Direct antibacterial and antibiotic resistance modulatory activity of chalcones synthesized from the natural product 2-hydroxy-3,4,6-trimethoxyacetophenone

Antibiotic for clinical use lose its effectiveness over time due to bacterial resistance. In this work, four chalcones with modifications in their ligands were synthesized from the natural product 2-hydroxy-3,4,6-trimethoxyacetophenone, characterized by nuclear magnetic resonance (NMR) and infrared spectroscopy, and tested in bacterial models to investigate the direct and modifiers effects of the antibiotic activity of these four novel chalcones. The tests followed the broth microdilution methodology to obtain the Minimum Inhibitory Concentration (MIC). The MIC/8 of the products were used in the resistance reversion test. The chalcone 2 showed the best result in terms of direct activity, with MIC 645 μg/mL for Staphylococcus aureus and 812 μg/mL for Escherichia coli. While, for the bacterial resistance reversal test, the chalcones presented several synergistic interactions, being that chalcone 4 had the best interaction with the tested antibiotics. It was found that the type of ligand, as well as its position in the ring, interferes in the modulation of the antibiotic activity. Our results show that chalcones are strong candidates to be used as antibacterial drug or in combination with antibiotics for the treatment of infections caused by multidrug-resistant (MDR) strains.

Antitumor activity associated with hyperthermia and 4-nitrochalcone loaded in superparamagnetic poly(thioether-ester) nanoparticles

The combination of hyperthermia and chemotherapy has a potential synergic effect in antitumor activity. The development of new biocompatible and biodegradable polymers to simultaneously encapsulate magnetic nanoparticles (MNPs) and antitumoral drugs offer new cancer treatment opportunities. Here, biodegradable and biocompatible poly(thioether-ester) (PTEe) was used to encapsulate MNPs and 4-nitrochalcone (4NC) using miniemulsification and solvent evaporation. The resulting hybrid particles (MNPs-4NC-PTEe) had nanometer-scale diameters, spherical morphology, negative surface charge, high encapsulation efficiency, and superparamagnetic properties. Results showed that 4NC release occurred through diffusion. Free 4NC and MNPs + 4NC-PTEe did not have any cytotoxic effect on erythrocytes and mouse embryonic fibroblast (NIH3T3) cells. 4NC antitumor activity was verified on human cervical cancer (HeLa) and melanoma (B16F10) cells. Cellular uptake of MNPs + 4NC-PTEe nanoparticles was higher in HeLa cells compared to B16F10 and NIH3T3 cells. The hyperthermia application (115 kHz-500 Oe) potentiated the 4NC effects on HeLa and B16F10 cells when MNPs + 4NC-PTEe nanoparticles were used, indicating more effective antitumor activity. We concluded that the use of MNPs + 4NC-PTEe nanoparticles associated with hyperthermia is a promising form of treatment for some types of cancers.

Aldehyde biphenyl chalcones induce immunogenic apoptotic-like cell death and are promising new safe compounds against a wide range of hematologic cancers

Aim: Investigate the apoptotic mechanisms of two new aldehyde biphenyl chalcones on leukemia cells. Materials & methods: From a series of 71 new chalcones, we selected the two most cytotoxic. Results: JA3 and JA7 were cytotoxic not only against hematological malignancies but also against solid tumor and cancer stem cells, yet with no toxicity to normal cells. Moreover, they induced immunogenic apoptotic-like cell death independently of promyelocytic leukemia protein, with extensive mitochondrial damages downstream of endoplasmic reticulum stress. Preventing endoplasmic reticulum stress and the upregulation of proapoptotic machinery inhibited JA3- and JA7-induced cell death. Likewise, blocking receptor Fas protected cells from killing. They increased the antileukemic effect of cytarabine and vincristine and killed leukemic cells collected from patients with different acute leukemia subtypes. Conclusion: JA3 and JA7 represent new promising prototypes for the development of new chemotherapeutics.

Biological evaluation of non-basic chalcone CYB-2 as a dual ABCG2/ABCB1 inhibitor

The enhancement of drug efflux caused by ATP-binding cassette (ABC) transporters (including ABCG2 and ABCB1) overexpression is an important factor for multidrug resistance (MDR) in cancers. After testing the reversal activities of 19 chalcone and bis-chalcone derivatives on MDR cancer cell lines, we found that non-basic chalcone CYB-2 exhibited the most potent reversal activities against both ABCG2- and ABCB1-mediated MDR. The mechanistic studies show that this compound can increase the accumulation of anticancer drugs in both ABCG2- and ABCB1-overexpressing cancer cell lines, resulting from the blocked efflux function of the MDR cancer cell lines. This inhibition is due to the barred ABCG2 and ABCB1 ATPase activities rather than altering the expression or localization of ABCG2 or ABCB1 transporters. The previous studies showed that non-basic chalcones were ABCG2-specific inhibitors; however, we found that non-basic chalcone CYB-2 can be developed as an ABCG2/ABCB1 dual inhibitor to overcome MDR in cancers that co-express both ABCG2 and ABCB1. Moreover, non-basic chalcone CYB-2 has synthetic tractability compared to other chalcone-based derivatives.

Curcumin and Its Derivatives as Potential Therapeutic Agents in Prostate, Colon and Breast Cancers

Cancer is a life-threatening disease and is the second leading cause of death around the world. The increasing threats of drug-resistant cancers indicate that there is an urgent need for the improvement or development of more effective anticancer agents. Curcumin, a phenolic compound originally derived from turmeric plant (Curcuma longa L. (Zingiberaceae family)) widely known as a spice and a coloring agent for food have been reported to possess notable anticancer activity by inhibiting the proliferation and metastasis, and enhancing cell cycle arrest or apoptosis in various cancer cells. In spite of all these benefits, the therapeutic application of curcumin in clinical medicine and its bioavailability are still limited due to its poor absorption and rapid metabolism. Structural modification of curcumin through the synthesis of curcumin-based derivatives is a potential approach to overcome the above limitations. Curcumin derivatives can overcome the disadvantages of curcumin while enhancing the overall efficacy and hindering drug resistance. This article reports a review of published curcumin derivatives and their enhanced anticancer activities.

Germacrone cooperates with dexmedetomidine to alleviate high-fat diet-induced type 2 diabetes mellitus via upregulating AMPKα1 expression

The aim of the present study was to investigate the effects of germacrone (GM) and dexmedetomidine (DEX) in treating type 2 diabetes mellitus (T2DM). A high-fat diet (HFD)-induced T2DM rat model was established. The experimental rats were divided into the control group, HFD group, GM treatment group, DEX treatment group and GM + DEX treatment group. In addition, adenosine monophosphate-activated protein kinase (AMPK) inhibitor compound C (CC) was used to inhibit AMPKα1 expression. All rats received their respective treatment daily for 21 days. Blood glucose and lipid levels, apoptosis of hepatic cells, and levels of inflammatory factors and oxidative stress indicators in serum samples were evaluated. Protein expression of AMPKα1 and its downstream targets were also investigated. Results demonstrated that blood glucose concentration, blood lipid indicators (endothelin, total cholesterol, triglyceride and low density lipoprotein cholesterol), cell apoptosis in liver tissues, total oxidant status, malondialdehyde, interleukin (IL)-6, tumor necrosis factor-α (TNF-α) and IL-1β levels in serum were increased in the high-fat group compared to the control but decreased following GM and/or DEX treatment. By contrast, high-density lipoprotein cholesterol and antioxidative stress indicator superoxide dismutase (SOD) were decreased in the high-fat group but increased following GM and/or DEX treatment. Protein expression of AMPKα1 and the catabolic genes carnitine palmitoyltransferase-1, peroxisome proliferator-activated receptor-α and acyl coenzyme A were decreased whilst anabolic genes, including sterol regulatory element binding protein-1c, fatty acid synthase and diacylglycerol acyltransferase-2, were increased in the HFD group. These effects were attenuated by GM and/or DEX treatment. AMPKα1 inhibition resulted in decreased SOD and increased cell apoptosis in liver tissues as well as increased IL-6, TNF-α and IL-1β levels compared with the HFD group. However, these effects were abolished following treatment with CC, GM and DEX together. Taken together these results indicated that GM worked synergistically with DEX to attenuate symptoms of high-fat-induced T2DM, with the effect potentially involving an increase in AMPKα1 expression.

Methoxychalcones: Effect of Methoxyl Group on the Antifungal, Antibacterial and Antiproliferative Activities

BACKGROUND

Chalcones substituted by methoxyl groups have presented a broad spectrum of bioactivities, including antifungal, antibacterial and antiproliferative effects. However, a clear and unambiguous investigation about the relevance of this substituent on the chalcone framework has not been described.

OBJECTIVE

The purpose of this work is to assess the antibacterial, antifungal and antiproliferative activities of the two series of seventeen synthesized regioisomeric methoxychalcones. Series I and II were constituted by chalcones substituted by methoxyl groups on rings A (5-12) and B (13-21), respectively. In addition, the library of methoxychalcones was submitted to in silico drug-likeness and pharmacokinetics properties predictions.

METHODS

Methoxychalcones were synthesized and their structures were confirmed by NMR spectral data analyses. Evaluations of antimicrobial activity were performed against five species of Candida, two Gram-negative and five Gram-positive species. For antiproliferative activity, methoxychalcones were evaluated against four human tumorigenic cell lines, as well as human non-tumorigenic keratinocytes. Drug-likeness and pharmacokinetics properties were predicted using Molinspiration and PreADMET toolkits.

RESULTS

In general, chalcones of series I are the most potent antifungal, antibacterial and antiproliferative agents. 3', 4', 5'-Trimethoxychalcone (12) demonstrated potent antifungal activity against Candida krusei (MIC = 3.9 μg/mL), eight times more potent than fluconazole (reference antifungal drug). 3'-Methoxychalcone (6) displayed anti-Pseudomonas activity (MIC = 7.8 μg/mL). 2',5'-Dimethoxychalcone (9) displayed potent antiproliferative effect against C-33A (cervix), A-431 (skin) and MCF-7 (breast), with IC50 values ranging from 7.7 to 9.2 μM. Its potency was superior to curcumin (reference antiproliferative compound), which exhibited IC50 values ranging from 10.4 to 19.0 μM.

CONCLUSION

Our studies corroborated the relevance of methoxychalcones as antifungal, antibacterial and antiproliferative agents. In addition, we elucidated influence of the position and number of methoxyl groups toward bioactivity. In silico predictions indicated good drug-likeness and pharmacokinetics properties to the library of methoxychalcones.

Antiproliferative activity and p53 upregulation effects of chalcones on human breast cancer cells

Chalcones are valuable structures for drug discovery due to their broad bioactivity spectrum. In this study, we evaluated 20 synthetic chalcones against estrogen-receptor-positive breast cancer cells (MCF-7 line) and triple-negative breast cancer (TNBC) cells (MDA-MB-231 line). Antiproliferative screening by MTT assay resulted in two most active compounds: 2-fluoro-4’-aminochalcone (11) and 3-pyridyl-4’-aminochalcone (17). Their IC₅₀ values ranged from 13.2 to 34.7 µM against both cell lines. Selected chalcones are weak basic compounds and maintained their antiproliferative activity under acidosis conditions (pH 6.7), indicating their resistance to ion-trapping effect. The mode of breast cancer cells death was investigated and chalcones 11 and 17 were able to induce apoptosis rather than necrosis in both lines. Antiproliferative target investigations with MCF-7 cells suggested 11 and 17 upregulated p53 protein expression and did not affect Sp1 protein expression. Future studies on chalcones 11 and 17 can define their in vivo therapeutic potential.

Synthesis and Anti-inflammatory Evaluation of ( R)-, ( S)-, and (±)-Sanjuanolide Isolated from Dalea frutescens

The known chalcone (±)-sanjuanolide (1) can be isolated from Dalea frutescens. This study presents a convergent strategy for the first total synthesis of ( R)-, ( S)-, and (±)-sanjuanolide (1). The key step for synthesizing ( R)- and ( S)-1 was a Corey-Bakshi-Shibata enantioselective carbonyl reduction to construct the C-2″ configuration. ( R)-1 efficiently inhibited the lipopolysaccharides (LPS)-induced expression of tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6), while ( S)-1 produced no significant anti-inflammatory effect. ( R)-1 also effectively inhibited the mRNA expression of several inflammatory cytokines after the LPS challenge in vitro. The synthesis and biological properties of these compounds have confirmed ( R)-sanjuanolide and (±)-sanjuanolide as promising new leads for developing anti-inflammatory agents.

Anti-Trichomonas vaginalis activity of chalcone and amino-analogues

Trichomoniasis is the most common non-viral sexually transmitted disease worldwide and can lead to serious consequences in reproductive health, cancer, and HIV acquisition. The current approved treatment present adverse effects and drug resistance data on this neglected parasitic infection is underestimated. Chalcones are a family of molecules that present biological applications, such as activity against many pathogenic organisms including protozoan pathogens. Chalcone (1) and three amino-analogues (2-4) were synthesized by Claisen-Schmidt condensation reaction and had their activity evaluated against the parasitic protozoan Trichomonas vaginalis. This bioassay indicated the presence and position of the amino group on ring A was crucial for anti-T. vaginalis activity. Among these, 3'-aminochalcone (3) presented the most potent effect and showed high cytotoxicity against human vaginal cells. On the other hand, 3 was not able to exhibit toxicity against Galleria mellonella larvae, as well as the hemolytic effect on human erythrocytes. Trophozoites of T. vaginalis were treated with 3, and did not present significant reactive oxygen species (ROS) accumulation, but induced a significantly higher ROS accumulation in human neutrophils after co-incubation. T. vaginalis pyruvate:ferredoxin oxidoreductase (PFOR) and β-tubulin gene expression was not affected by 3.

Antibacterial Activity of Chalcone and Dihydrochalcone Compounds from Uvaria chamae Roots against Multidrug-Resistant Bacteria

This study presents antimicrobial properties of Uvaria chamae roots, commonly used for the treatment of various infections in south Benin. Their constituents were extracted and then fractionated in order to isolate the active ingredients. Antimicrobial susceptibility tests were performed against several multidrug-resistant bacteria using the Mueller Hilton well agar diffusion method. Results showed that ethanol extracts were highly active against Gram-positive cocci. This activity was more extensive than that measured from conventional broad-spectrum antibiotics. Indeed, vancomycin-resistant enterococcus (VRE) and methicillin-resistant Staphylococcus aureus (MRSA) strains were all sensitive to this root extract. The aim of this study was to link the antimicrobial activity of the root to chemical structures. The ion mobility mass spectrometry analysis revealed for the first time the presence of ten chalcone and dihydrochalcone structures responsible for the antimicrobial activity of Uvaria chamae ethanol extracts. Two structures were described here for the first time in these roots. These findings confirm and justify the medical properties of these roots used as a traditional medicine.

Novel 1,3,4-thiadiazole-chalcone hybrids containing catechol moiety: synthesis, antioxidant activity, cytotoxicity and DNA interaction studies

Hybrid compounds that combine the 1,3,4-thiadiazole-containing catechol moiety with a chalcone motif were synthesized and examined for their antioxidant activity, cytotoxicity, and DNA-binding activity. A series of thirteen compounds showed strong antioxidant and cytotoxic effects on human acute promyelocytic leukemia HL-60 cells. Several compounds exerted good cytotoxic activities on cervical adenocarcinoma HeLa cells. The treatment of HeLa cells with IC₅₀ and double IC₅₀ concentrations of the compounds 5a, 5c, 5f, and 5m induced a statistically significant increase in the percentage of cells within a subG1 cell cycle phase. The examined compounds caused G2/M cell cycle arrest in HeLa cells. Each of these compounds triggered apoptosis in HeLa cells through activation of caspase-3, the main effector caspase, caspase-8, which is involved in the extrinsic apoptotic pathway, and caspase-9, which is involved in the intrinsic apoptotic pathway. All of the examined compounds decreased the expression levels of MMP2 in HeLa cells and levels of protumorigenic miR-133b. Compounds 5a and 5m lowered the expression level of oncogenic miR-21 in HeLa cells. In addition, compounds 5a, 5f, and 5m decreased the expression levels of oncogenic miR-155 while the treatment of HeLa cells with compounds 5a, 5c, and 5f increased expression of tumor-suppressive miR-206. Observed effects of these compounds on expression levels of four examined miRNAs suggest their prominent cancer-suppressive activity. An investigation by absorption and fluorescence spectroscopy showed more efficient calf thymus DNA binding activity of the compound 5m in comparison to other tested compounds. Results of a pUC19 plasmid cleavage study and comet assay showed DNA damaging activities of compounds 5a and 5c.

Synthesis, Antimicrobial, and Computational Evaluation of Novel Isobutylchalcones as Antimicrobial Agents

A series of 25 new chalcones were synthesized by Claisen-Schmidt condensation, well characterized by spectroscopic data, and evaluated for their antibacterial and antifungal activities by serial tube dilution method. Among the compounds tested, A3 and A6 containing 2,4-dichlorophenyl and 2,4-difluorophenyl moiety, respectively, were found to be the most potent in the series against both bacterial and fungal strains with a MIC value of 16 µg/mL in each case. Further computational evaluation for antimicrobial activity was performed by atom based 3D-QSAR using PHASE™ software in order to have a correlation between the observed activities and predicted activities. The computational studies were in agreement with the in vitro antimicrobial results and had identified the most promising chalcones as antimicrobial agents and the responsible structural features for the proposed activity.

Cytotoxicity anticancer activities of anastrozole against breast, liver hepatocellular, and prostate cancer cells

OBJECTIVES

To investigate the cytotoxic effect of anastrozole on breast (MCF7), liver hepatocellular (HepG2), and prostate (PC3) cancer cells. Methods: This is a prospective study. Anastrozole's mechanism of apoptosis in living cells was also determined by high content screening (HCS) assay. Methylthiazol tetrazolium (MTT) assay was carried out at the Centre of Biotechnology Research's, Al-Nahrain University, Baghdad, Iraq between July 2015 and October 2015. The HCS assay was performed at the Centre for Natural Product Research  and Drug Discovery, Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia between November 2015 and February 2016. Results: The most significant cytotoxic effect of anastrozole towards 3 cancer cell lines was obtained when its concentration was 400 µg/mL. The MCF7 cells were more sensitive to anastrozole compared with the HepG2 and PC-3 cells. There was a significant increase in membrane permeability, cytochrome c and nuclear intensity when anastrozole (200 µg/mL) was used compared with doxorubicin (20 µg/mL) as a standard. Also, there was a significant decrease in cell viability and mitochondrial membrane permeability when anastrozole (200 µg/mL) was used compared with positive control. Conclusion: Anastrozole showed cytotoxic effects against the MCF7, HepG2, and PC3 cell lines as determined in-vitro by the MTT assay. The HCS technique also showed toxic effect towards MCF7. It is evident that anastrozole inhibits the aromatase enzyme preventing the aromatization mechanism; however, it has a toxic effect.

Synthesis and evaluation of modified chalcone based p53 stabilizing agents

Tumor suppressor protein p53 induces cell cycle arrest and apoptotic cell death in response to various cellular stresses thereby preventing cancer development. Activation and stabilization of p53 through small organic molecules is, therefore, an attractive approach for the treatment of cancers retaining wild-type p53. In this context, a series of nineteen chalcones with various substitution patterns of functional groups including chloro, fluoro, methoxy, nitro, benzyloxy, 4-methyl benzyloxy was prepared using Claisen-Schmidt condensation. The compounds were characterized using NMR, HRMS, IR and melting points. Evaluation of synthesized compounds against human colorectal (HCT116) and breast (CAL-51) cancer cell lines revealed potent antiproliferative activities. Nine compounds displayed GI₅₀ values in the low micromolar to submicromolar range; for example (E)-1-phenyl-3-(3,4,5-trimethoxyphenyl)prop-2-en-1-one (SSE14108) showed GI₅₀ of 0.473±0.043µM against HCT116 cells. Further analysis of these compounds revealed that (E)-3-(4-chlorophenyl)-1-phenylprop-2-en-1-one (SSE14105) and (E)-3-(4-methoxyphenyl)-1-phenylprop-2-en-1-one (SSE14106) caused rapid (4 and 8-h post-treatment) accumulation of p53 in HCT116 cells similar to its induction by positive control, Nutlin-3. Such activities were absent in 3-(4-methoxyphenyl)propiophenone (SSE14106H2) demonstrating the importance of conjugated ketone for antiproliferative and p53 stabilizing activity of the chalcones. We further evaluated p53 levels in the presence of cycloheximide (CHX) and the results showed that the p53 stabilization was regulated at post-translational level through blockage of its degradation. These chalcones can, therefore, act as fragment leads for further structure optimization to obtain more potent p53 stabilizing agents with enhanced anti-proliferative activities.

Chalcone: A Privileged Structure in Medicinal Chemistry

Privileged structures have been widely used as an effective template in medicinal chemistry for drug discovery. Chalcone is a common simple scaffold found in many naturally occurring compounds. Many chalcone derivatives have also been prepared due to their convenient synthesis. These natural products and synthetic compounds have shown numerous interesting biological activities with clinical potentials against various diseases. This review aims to highlight the recent evidence of chalcone as a privileged scaffold in medicinal chemistry. Multiple aspects of chalcone will be summarized herein, including the isolation of novel chalcone derivatives, the development of new synthetic methodologies, the evaluation of their biological properties, and the exploration of the mechanisms of action as well as target identification. This review is expected to be a comprehensive, authoritative, and critical review of the chalcone template to the chemistry community.

Functional evaluation of synthetic flavonoids and chalcones for potential antiviral and anticancer properties

Flavonoids, stilbenes, and chalcones are plant secondary metabolites that often possess diverse biological activities including anti-inflammatory, anti-cancer, and anti-viral activities. The wide range of bioactivities poses a challenge to identify their targets. Here, we studied a set of synthetically generated flavonoids and chalcones to evaluate for their biological activity, and compared similarly substituted flavonoids and chalcones. Substituted chalcones, but not flavonoids, showed inhibition of viral translation without significantly affecting viral replication in cells infected with hepatitis C virus (HCV). We suggest that the chalcones used in this study inhibit mammalian target of rapamycin (mTOR) pathway by ablating phosphorylation of ribosomal protein 6 (rps6), and also the kinase necessary for phosphorylating rps6 in Huh7.5 cells (pS6K1). In addition, selected chalcones showed inhibition of growth in Ishikawa, MCF7, and MDA-MB-231 cells resulting an IC₅₀ of 1-6µg/mL. When similarly substituted flavonoids were used against the same set of cancer cells, we did not observe any inhibitory effect. Together, we report that chalcones show potential for anti-viral and anti-cancer activities compared to similarly substituted flavonoids.

Polyphenols: Extraction Methods, Antioxidative Action, Bioavailability and Anticarcinogenic Effects

Being secondary plant metabolites, polyphenols represent a large and diverse group of substances abundantly present in a majority of fruits, herbs and vegetables. The current contribution is focused on their bioavailability, antioxidative and anticarcinogenic properties. An overview of extraction methods is also given, with supercritical fluid extraction highlighted as a promising eco-friendly alternative providing exceptional separation and protection from degradation of unstable polyphenols. The protective role of polyphenols against reactive oxygen and nitrogen species, UV light, plant pathogens, parasites and predators results in several beneficial biological activities giving rise to prophylaxis or possibly even to a cure for several prevailing human diseases, especially various cancer types. Omnipresence, specificity of the response and the absence of or low toxicity are crucial advantages of polyphenols as anticancer agents. The main problem represents their low bioavailability and rapid metabolism. One of the promising solutions lies in nanoformulation of polyphenols that prevents their degradation and thus enables significantly higher concentrations to reach the target cells. Another, more practiced, solution is the use of mixtures of various polyphenols that bring synergistic effects, resulting in lowering of the required therapeutic dose and in multitargeted action. The combination of polyphenols with existing drugs and therapies also shows promising results and significantly reduces their toxicity.

Hydroxychalcone inhibitors of Streptococcus mutans glucosyl transferases and biofilms as potential anticaries agents

Streptococcus mutans has been implicated as the major etiological agent in the initiation and the development of dental caries due to its robust capacity to form tenacious biofilms. Ideal therapeutics for this disease will aim to selectively inhibit the biofilm formation process while preserving the natural bacterial flora of the mouth. Several studies have demonstrated the efficacies of flavonols on S. mutans biofilms and have suggested the mechanism of action through their effect on S. mutans glucosyltransferases (Gtfs). These enzymes metabolize sucrose into water insoluble and soluble glucans, which are an integral measure of the dental caries pathogenesis. Numerous studies have shown that flavonols and polyphenols can inhibit Gtf and biofilm formation at millimolar concentrations. We have screened a group of 14 hydroxychalcones, synthetic precursors of flavonols, in an S. mutans biofilm assay. Several of these compounds emerged to be biofilm inhibitors at low micro-molar concentrations. Chalcones that contained a 3-OH group on ring A exhibited selectivity for biofilm inhibition. Moreover, we synthesized 6 additional analogs of the lead compound and evaluated their potential activity and selectivity against S. mutans biofilms. The most active compound identified from these studies had an IC50 value of 44μM against biofilm and MIC50 value of 468μM against growth displaying >10-fold selectivity inhibition towards biofilm. The lead compound displayed a dose dependent inhibition of S. mutans Gtfs. The lead compound also did not affect the growth of two commensal species (Streptococcus sanguinis and Streptococcus gordonii) at least up to 200μM, indicating that it can selectively inhibit cariogenic biofilms, while leaving commensal and/or beneficial microbes intact. Thus non-toxic compounds have the potential utility in public oral health regimes.

A Benzochalcone Derivative, (E)-1-(2-hydroxy-6-methoxyphenyl)-3-(naphthalen-2-yl)prop-2-en-1-one (DK-512), Inhibits Tumor Invasion through Inhibition of the TNFα-Induced NF-κB/MMP-9 Axis in MDA-MB-231 Breast Cancer Cells

Tumor invasion is a critical step in tumor metastasis. In this study, we synthesized a novel benzochalcone derivative, (E)-1-(2-hydroxy-6-methoxyphenyl)-3-(naphthalen-2-yl) prop-2-en-1-one (DK-512), and characterized its effects on tumor invasion and its mechanism of action. We found that DK-512 strongly inhibited invasion of metastatic MDA-MB-231 breast cancer cells as revealed by a three-dimensional spheroid culture system. Tumor invasion and metastasis require disruption of the extracellular matrix. Matrix metalloproteinase-9 (MMP-9) is an endopeptidase that degrades extracellular matrix components. DK-512 significantly reduced tumor necrosis factor-α- (TNFα-) induced MMP-9 mRNA expression through the inhibition of RelA nuclear factor- (NF-)κB transcription factor. As our study was assessedin vitro, further works aboutin vivoefficacy of DK-512 are needed to gain further insights into whether DK-512 could be utilized as a scaffold for the development of antimetastatic agents for breast cancer.