In vitro antioxidant and antiproliferative effects of ellagic acid and its colonic metabolite,urolithins, on human bladder cancer T24 cells

Urolithins were the metabolites of ellagic acid by intestinal flora in gastrointestinal tract. In previous research, it was found that urolithins could mainly inhibit prostate cancer and colon cancer cell growth. However, there is no report about bladder cancer therapy of urolithins. In this paper, three urolithin-type compounds (urolithin A, urolithin B, 8-OMe-urolithin A) and ellagic acid were evaluated for antiproliferative activity in vitro against human bladder cancer cell lines T24. The IC₅₀ values for T24 cell inhibition were 43.9, 35.2, 46.3 and 33.7 μM for urolithin A, urolithin B, 8-OMe-urolithin A and ellagic acid, respectively. After the administration of urolithins and ellagic acid, we found these compounds could increase mRNA and protein expression of Phospho-p38 MAPK, and decrease mRNA and protein expression of MEKK1 and Phospho-c-Jun in T24 cells. Caspase-3 was also activated and PPAR-γ protein expression increased in drug-induced apoptosis. And what’s more, the antioxidant assay afforded by three urolithins and EA treatments were associated with decreases in the intracellular ROS and MDA levels, and increased SOD activity in H₂O₂-treated T24 cells. The results suggested that these compounds could inhibit cell proliferation by p38-MAPK and/or c-Jun medicated caspase-3 activation and reduce the oxidative stress status in bladder cancer.     

Indicine N-oxide binds to tubulin at a distinct site and inhibits the assembly of microtubules: A mechanism for its cytotoxic activity

Indicine N-oxide, a pyrrolizidine alkaloid present in the plant Heliotropium indicum had shown promising cytotoxic activity in various tumor models. The compound exhibited severe toxicity to hepatocytes and bone marrow cells. The present work was aimed to evaluate the molecular mechanism of the toxicity of indicine N-oxide. We found that indicine N-oxide inhibited the proliferation of various cancer cell lines in a concentration dependent manner with IC₅₀ ranging from 46 to 100 μM. At the half maximal inhibitory concentration it blocked the cell cycle progression at mitosis without significantly altering the organization of the spindle and interphase microtubules. The toxicities of the compound at higher concentrations are attributed to its severe depolymerizing effect on both the interphase and spindle microtubules. Binding studies using purified goat brain tubulin indicated that indicine N-oxide binds to tubulin at a distinct site not shared by colchicine or taxol. It decreased the polymer mass of both purified tubulin and MAP-rich tubulin. It was found to induce cleavage of DNA using pUC18 plasmid. The interactions of indicine N-oxide on DNA were also confirmed by computational analysis; which predicted its binding site at the minor groove of DNA. These studies bring to light that the toxicities of indicine N-oxide were due to its DNA damaging effects and depolymerization of microtubules.     

Essential oils of Salvia bracteata and Salvia rubifolia from Lebanon: Chemical composition,antimicrobial activity and inhibitory effect on human melanoma cells

Aim of the study

Salvia bracteata Banks et Sol. and Salvia rubifolia Boiss. are known in folk medicine of Lebanon for the treatment of microbial infections, cancer, urinary and pulmonary problems. In the present study the chemical composition and antimicrobial activity of essential oils from aerial parts of Salvia bracteata and Salvia rubifolia collected in Lebanon were evaluated. The oils were also tested for their potential antiproliferative effects against M14 human melanoma cells.

Material and methods

The oils were studied by GC and GC–MS and their antibacterial activity (MIC and MBC) was tested against ten bacteria species using the broth dilution method. The inhibitory effect on human melanoma cells (measurement of cell vitality, cell membrane integrity and genomic DNA fragmentation) was studied using MTT assay, calculation of LDH release and COMET assay.

Results

The oils showed a good antibacterial activity (MIC = 50 μg/ml) against Gram+ bacteria. They besides exhibited an inhibitory effect on the human cancer cells examined inducing also apoptotic cell death, but the oil of Salvia rubifolia was significantly (p < 0.001) more active as compared to the oil of Salvia bracteata.

Conclusion

The results on the pharmacological activities of these Salvia species provide an in vitro scientific support for the use of these plants in traditional herbal preparations.     

Synthesis and antiproliferative activity in vitro of 2-aminobenzimidazole derivatives

A novel series of Schiff bases 1-11, the derivatives of 2-aminobenzimidazole and substituted aromatic aldehydes, has been synthesised. Compounds 1-11 reduced by NaBH(4) formed 2-benzylaminobenzimidazoles 12-21. 2-(o-Bromobenzylamino)benzimidazole (15) acylated by cinnamoyl chloride gave 2-(o-bromobenzylamino)-1-cinnamoylbenzimidazole (22). Long heating of 15 and 19 with p-nitrocinnamoyl or cinnamoyl chloride led to the formation of pyrimido[1,2-a]benzimidazol-4-ones 23 and 24. The structures of 1-24 were identified by the results of elemental analysis and their IR, (1)H NMR and MS spectra. Among the compounds 1-24 evaluated for their antiproliferative activity in vitro, 16, 19, 20 and 22 exhibited cytotoxic activity against the cells of human cancer cell lines, namely SW707 (rectal), HCV29T (bladder), A549 (lung) and T47D (breast cancer).     

Synthesis and in vitro antileukemic activity of new 4-triazenopyrazole derivatives

Several new 4-(3,3-dimethyltriazeno)-5-benzamidopyrazole derivatives were prepared by reacting 4-diazo-5-benzamidopyrazole derivatives with dimethylamine. The compounds were tested at 10 microM for their vitro antileukemic activity against K562 (Human chronic myelogenous leukemia) and Raji (human Burkitt limphoma ) cell lines. Dacarbazine and methotrexate were used for comparative purpose. The 3-methyl-4-(3,3-dimethyltriazeno)-5-(substituted benzamido)pyrazoles, bearing the pyrazole nucleus free at 1 position, resulted more active than the 1-(substituted phenyl)-3-methyl-4-(3,3-dimethyltriazeno)-5-benzamidopyrazoles. Dacarbazine at 10 microM showed no activity in the above tests. The observed difference among Dacarbazine and the active 4-triazenopyrazoles migth be explained admiting that these last compounds, differently by Dacarbazine, did not follow a mechanism of action based on the cytochrome P-450 induced demethylation. The most active compound 2d showed growth inhibition values of 97.8 and 99.4% against K562 and Raji cell lines respectively. Methotrexate inhibition values at 0.2 microM against the above cell lines were 86.7 and 75.1% respectively.     

Liposomes containing distamycins: preparation, characterization and antiproliferative activity

This article describes the production and characterization of two liposome formulations containing antitumor drugs, namely distamycin A (Dist) and a new alkyl derivative of distamycin A (C₁₆-Dist). Egg-PC/cholesterol liposomes (4:1 mol/mol) were prepared by reverse phase evaporation technique followed by extrusion through polycarbonate filters. The encapsulation efficiency was found to be almost complete for C₁₆-Dist (99.8%), while native distamycin A showed a lower yield (19.0%). The in vitro antiproliferative activity of the distamycins-containing liposomes determined on human leukaemic K562 cells, was 11-fold and 8-fold higher for native and alkyl derivative distamycin A, respectively, compared with that of the corresponding free drugs. Liposomal formulations show an increase in the activity and specificity of distamycins in experimental antitumor therapy.     

Effect of antiproliferative agents on vascular function in normal and in vitro balloon-injured porcine coronary arteries

Local infusion of antiproliferative agents following coronary balloon angioplasty is used in vivo. This study examined the effects of the antiproliferative agents paclitaxel (5-beta, 20-Epoxy-1,2-alpha,4,7-beta,10-beta,13-alpha-Hexahydroxy-Tax-11-en-9-one 4,10-Diacetate 2_Benzoate 13-Ester with (2R,3S)-N-Benzoyl-3-Phenylisoserine; 10 and 50 microM), farnesyl protein transferase inhibitor III (FPT III, (E,E)-2-[2-Oxo-2-[(3,7,11-trimethyl-2,6,10-dodecatrienyl) oxy] amino] ethyl] phosphonic acid, (2,2-dimethyl-1-oxopropoxy) methyl ester, sodium); 10 and 25 microM), perillyl alcohol (4-isopropenyl-cyclohexenecarbinol; 1 and 2 mM) and Van 10/4 (Decahydro-1,1,4,7-tetramethyl-1H-cycloprop[e]azulen-4-o-[2-(3-methylpent-2-enoyl)-fucopyranoside]; 10 and 25 microM) on normal and in vitro balloon-injured porcine coronary arteries. Short-term (30 min) incubation had no effect on contraction or relaxation. Overnight incubation with 25 microM Van 10/4-attenuated contraction while perillyl alcohol abolished contractility completely. Endothelium-dependent relaxation was significantly attenuated by the higher concentration of paclitaxel, FPT III and Van 10/4. Stretch injury significantly enhanced sensitivity to 3-morpholinosydnonimine (SIN-1) while attenuating relaxation to calcimycin. Drug incubation (15 min) had no effect on these responses. In conclusion, paclitaxel, FPT III and Van 10/4 have no detrimental effects on vascular function after short-term administration to normal or stretch-injured arteries.     

In-vitro antiproliferative activity of benzopyranone derivatives in comparison with standard chemotherapeutic drugs

The cytotoxic activities of five new benzopyranone derivatives containing basic amino side chain are described. Their cytotoxicities against ER(+) MCF‐7 and ER(–) MDA‐MB‐231 human breast cancer cell lines, and Ishikawa human endometrial cell line were determined after 72 h drug exposure employing CellTiter‐Glo assay at concentrations ranging from 0.01–1.0 × 10⁵ nM. The antiproliferative activities of these compounds were compared to tamoxifen (TAM), 4‐hydroxytamoxifen (4‐OHT, active metabolite of tamoxifen), and raloxifene (RAL). In‐vitro results indicated that compounds 9 , 10 , 12 , and 13 were more potent than TAM against the human breast cancer cell lines with IC₅₀ < 20 µM. The in‐silico structure–activity relationships of these compounds and their binding mode within the estrogen receptor (ER) binding site using AutoDock vina are discussed.