Chalcone arrests cell cycle progression and induces apoptosis through induction of mitochondrial pathway and inhibition of nuclear factor kappa B signalling in human bladder cancer cells

1,3-Diphenylpropenone ameliorates TNBS-induced rat colitis through suppression of NF-κB activation and IL-8 induction

In the present study, we examined whether newly synthesized phenylpropenone derivatives, by inhibiting NF-κB activity, would inhibit IL-8 expression, inflammation and abnormal angiogenesis, resulting in amelioration of disease conditions. The phenylpropenone derivatives inhibited NF-κB transcriptional activity, which correlated with their suppressive activity against TNF-α-induced adhesion of U937 human monocytic cells to HT-29 human colonic epithelial cells, an in vitro model of IBD. Among the derivatives, 1,3-diphenylpropenone (DPhP) was most efficacious, and it significantly suppressed TNF-α-induced production of IL-8 which is a proinflammatory and proangiogenic cytokine. The anti-inflammatory activity of DPhP was also confirmed in the trinitrobenzene sulfonic acid (TNBS)-induced rat colitis model. DPhP was protective against the TNBS-induced inflammatory responses, which included weight loss, increased myeloperoxidase activity and mucosal damage. In the colon tissue, DPhP inhibited TNBS-induced NF-κB nuclear translocation, IL-8 and TNF-α expressions, and abnormal angiogenesis. In addition, DPhP also suppressed IL-8-induced angiogenesis, which was revealed by an in vivo assay using chick chorioallantoic membrane. Furthermore, the level of IL-6, a pleiotropic cytokine which is implicated in the pathogenesis of IBD and colitis-associated cancer, was suppressed by DPhP in rat colon tissue and serum. In conclusion, the results suggest that DPhP is a potential dual-acting IBD drug candidate targeting both inflammation and abnormal angiogenesis, possibly through the NF-κB and IL-8 signaling pathway.

Activity of novel quinoxaline-derived chalcones on in vitro glioma cell proliferation

Gliomas are the most common and devastating tumors of the central nervous system (CNS). Many pieces of evidence point out the relevance of natural compounds for cancer therapy and prevention, including chalcones. In the present study, eight synthetic quinoxaline-derived chalcones, structurally based on the selective PI3Kγ inhibitor AS605240, were evaluated for anti-proliferative activity and viability inhibition using glioma cell lines from human and rat origin (U-138 MG and C6, respectively), at different time-periods of incubation and concentrations. The results revealed that four chalcones (compounds 1, 6, 7 and 8), which present methoxy groups at A-ring, displayed higher efficacies and potencies, being able to inhibit either cell proliferation or viability, in a time- and concentration-dependent manner, with an efficacy that was greater than that seen for the positive control compound AS605240. Flow cytometry analysis demonstrated that incubation of C6 cells with compound 6 led to G1 phase arrest, likely indicating an interference with apoptosis. Furthermore, compound 6 was able to visibly inhibit AKT activation, allied to the stimulation of ERK MAP-kinase. The chalcones tested herein, especially those displaying a methoxy substituent, might well represent promising molecules for the adjuvant treatment of glioma progression.

Induction of apoptosis and cell cycle arrest in L-1210 murine lymphoblastic leukaemia cells by (2E)-3-(2-naphthyl)-1-(3'-methoxy-4'-hydroxy-phenyl)-2-propen-1-one

OBJECTIVES

New compounds with biological targets and less cytotoxicity to normal cells are necessary for cancer therapy. In this work ten synthetic chalcones derived from 2-naphtaldehyde were evaluated for their cytotoxic effect in murine acute lymphoblastic leukemia cells L-1210.

METHODS

A series of ten chalcones derived from 2-naphtaldehyde and corresponding acetophenones were prepared by aldolic condensation, using methanol as solvent under basic conditions, at room temperature for 24 h. The cell viability was determined by MTT colorimeter method. The cell cycle phase analysis was carried out by flow cytometry after propidium iodide staining. The apoptosis induction was assessed by exposure to phosphatidylserine (ANNEXIN V-FITC). Cytometric analysis was performed to evaluate the expression of p53, Bcl-2 and Bax protein. The caspase-3 expression was studied by immunoblotting analysis.

KEY FINDINGS

A preliminary screening of a series of ten chalcones derived from 2-naphtaldehyde showed that chalcone 8, (2E)-3-(2-naphtyl)-1-(3'-methoxy-4'-hydroxy-phenyl)-2-propen-1-one, had the highest cytotoxic effect (IC50 of 54 microM), but not in normal human lymphocytes. To better understand the cytotoxic mechanism of chalcone 8, its effect on cell cycle and apoptosis was assessed. Our results showed that chalcone 8 caused cell cycle arrest in the G2/M phase and a significant increase in the proportion of cells in the subG0/G1 phase. Our results also demonstrated that chalcone 8 promoted a modification in Bax:Bcl-2 ratio and increased p53 expression and caspase-3 activation.

CONCLUSIONS

The studied chalcone 8 has cytotoxic effect against L-1210 lymphoblastic leukaemic cells, and this effect is associated with increase of p-53 and Bax expression.

Dietary chalcones with chemopreventive and chemotherapeutic potential

Chalcones are absorbed in the daily diet and appear to be promising cancer chemopreventive agents. Chalcones represent an important group of the polyphenolic family, which includes a large number of naturally occurring molecules. This family possesses an interesting spectrum of biological activities, including antioxidative, antibacterial, anti-inflammatory, anticancer, cytotoxic, and immunosuppressive potential. Compounds of this family have been shown to interfere with each step of carcinogenesis, including initiation, promotion and progression. Moreover, numerous compounds from the family of dietary chalcones appear to show activity against cancer cells, suggesting that these molecules or their derivatives may be considered as potential anticancer drugs. This review will focus primarily on prominent members of the chalcone family with an 1,3-diphenyl-2-propenon core structure. Specifically, the inhibitory effects of these compounds on the different steps of carcinogenesis that reveal interesting chemopreventive and chemotherapeutic potential will be discussed.

The role of chalcones in suppression of NF-κB-mediated inflammation and cancer

Although consumption of fruits, vegetables, spices, cereals and pulses has been associated with lower incidence of cancer and other chronic diseases, how these dietary agents and their active ingredients minimize these diseases, is not fully understood. Whether it is oranges, kawa, hops, water-lilly, locorice, wax apple or mulberry, they are all connected by a group of aromatic ketones, called chalcones (1,3-diaryl-2-propen-1-ones). Some of the most significant chalcones identified from these plants include flavokawin, butein, xanthoangelol, 4-hydroxyderricin, cardamonin, 2',4'-dihydroxychalcone, isoliquiritigenin, isosalipurposide, and naringenin chalcone. These chalcones have been linked with immunomodulation, antibacterial, antifungal, antiviral, anti-inflammatory, antioxidant, anticancer, and antidiabetic activities. The current review, however, deals with the role of various chalcones in inflammation that controls both the immune system and tumorigenesis. Inflammatory pathways have been shown to mediate the survival, proliferation, invasion, angiogenesis and metastasis of tumors. How these chalcones modulate inflammatory pathways, tumorigenesis and immune system is the focus of this review.

Effects of a combretastatin A4 analogous chalcone and its Pt-complex on cancer cells: A comparative study of uptake, cell cycle and damage to cellular compartments

The combretastatin A4 analogous chalcone (2E)-3-(3-hydroxy-4-methoxyphenyl)-1-(3,4,5-trimethoxyphenyl)prop-2-en-1-one 1 and its dichloridoplatinum(II) (6-aminomethylnicotinate) complex 2 were previously found to be highly active against a variety of cancer cell lines while differing in their apoptosis induction and long-term regrowth retardation (Schobert et al. [1]). Further differences were identified now. The cellular uptake of complex 2, like that of oxaliplatin, occurred mainly via organic cation transporters (OCT-1/2; ∼32%) and copper transporter related proteins (Ctr1; ∼24%), whereas that of chalcone 1 was dependent on endocytosis (∼80%). Complex 2 was more tumour-specific than 1 concerning neural cells. This was apparent from the ratios of IC(50)(48h) values against primary astrocytes versus human glioma cells U87 (>7000 for complex 2; 55 for compound 1). In tubulin-rich neurons and 518A2 melanoma cells complex 2 disrupted microtubules and actin filaments. Cancer cells treated with 2 could repair the cytoskeletal damage but ceased to proliferate and perished. Complex 2 was particularly cytotoxic against P-gp-rich cells. It acted as a substrate for ABC-transporters of types BCRP, MRP3, and MRP1 and so was less active against the corresponding cancer cell lines. Complex 2 arrested the cell cycle of the melanoma cells in G(1) and G(2)/M phases. A fragmentation of their Golgi apparatus was observed by TEM for incubation with complex 2 but not with 1. In conclusion, unlike chalcone 1, its platinum complex 2 is highly cell line specific, is taken up via cell-controlled transporters and induces apoptosis by triggering multiple targets.

Chalcones and dihydrochalcones augment TRAIL-mediated apoptosis in prostate cancer cells

Chalcones and dihydrochalcones exhibit chemopreventive and antitumor activity. TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) is a natural endogenous anticancer agent. We examined the cytotoxic and apoptotic effect of chalcones and dihydrochalcones on TRAIL-mediated apoptosis in LNCaP prostate cancer cells. The cytotoxicity was evaluated by the MTT and LDH assays. The apoptosis was detected using annexin V-FITC by flow cytometry and fluorescence microscopy. The DeltaPsim was evaluated using DePsipher staining by fluorescence microscopy. Our study showed that two tested chalcones (chalcone and 2',6'dihydroxy-4'-methoxychalcone) and three dihydrochalcones (2',6'-dihydroxy-4'4-dimethoxydihydrochalcone, 2',6'-dihydroxy-4'-methoxydihydro- chalcone, and 2',4',6'-trihydroxydihydrochalcone, called phloretin) markedly augmented TRAIL-induced apoptosis and cytotoxicity in LNCaP cells and confirmed the significant role of chalcones in chemoprevention of prostate cancer.

Comparative evaluation of cytotoxicity and antioxidative activity of 20 flavonoids

Flavonoids are common dietary components with many health benefits shown through epidemiological studies. However, the fact that flavonoids also act as pro-oxidants and mutagens makes the safety of flavonoids uncertain when used at higher doses. To give a preliminary evaluation on the correlation between beneficial and harmful effects of flavonoids, the antioxidative activity and cytotoxicity of 20 flavonoids from food and herbs were investigated in vitro. The results indicated that luteolin, hydroxygenkwanin, and kaempferol possessed significant dual properties, whereas flavokawain B, flavokawain C, cardamonin, and uvangoletin showed a marked cytotoxicity. The relationships between structure and antioxidant and cytotoxic activity are intensively discussed. In view of the toxicity, the intake of flavonoids in large amounts should not yet be encouraged.