ABSTRACT
The inhibitory effects of novel prodrugs, inclusion complexes of 3-(4'-geranyloxy-3'-methoxyphenyl)-2-trans propenoic acid (GOFA) and auraptene (AUR) with beta-cyclodextrin (CD), on colon carcinogenesis were investigated using an azoxymethane (AOM)/dextran sodium sulfate (DSS) model. Male CD-1 (ICR) mice initiated with a single intraperitoneal injection of AOM (10 mg/kg body weight) were promoted by the addition of 1.5% (w/v) DSS to their drinking water for 7 days. They were then given a basal diet containing 2 dose levels (100 and 500 ppm) of GOFA/beta-CD or AUR/beta-CD for 15 weeks. At Week 18, the development of colonic adenocarcinoma was significantly inhibited by feeding with GOFA/beta-CD at dose levels of 100 ppm (63% reduction in multiplicity, p < 0.05) and 500 ppm (83% reduction in the multiplicity, p < 0.001), when compared with the AOM/DSS group (multiplicity: 3.36 +/- 3.34). In addition, feeding with 100 and 500 ppm (p < 0.01) of AUR/beta-CD suppressed the development of colonic adenocarcinomas. The dietary administration with GOFA/beta-CD and AUR/beta-CD inhibited colonic inflammation and also modulated proliferation, apoptosis and the expression of several proinflammatory cytokines, such as nuclear factor-kappaB, tumor necrosis factor-alpha, Stat3, NF-E2-related factor 2, interleukin (IL)-6 and IL-1beta, which were induced in the adenocarcinomas. Our findings indicate that GOFA/beta-CD and AUR/beta-CD, especially GOFA/beta-CD, are therefore able to inhibit colitis-related colon carcinogenesis by modulating inflammation, proliferation and the expression of proinflammatory cytokines in mice.
Subject(s)
Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/prevention & control , Coumarins/therapeutic use , beta-Cyclodextrins/therapeutic use , Animals , Colonic Neoplasms/drug therapy , Colonic Neoplasms/pathology , Colorectal Neoplasms/epidemiology , Colorectal Neoplasms/mortality , Diterpenes/therapeutic use , Humans , Immunohistochemistry , Incidence , Inflammation/drug therapy , Inflammation/etiology , Inflammation/pathology , Inflammatory Bowel Diseases/complications , Inhibitor of Apoptosis Proteins , Interleukin-1beta/metabolism , Interleukin-6/metabolism , Male , Mice , Mice, Inbred ICR , Microtubule-Associated Proteins/metabolism , NF-kappa B/metabolism , Proliferating Cell Nuclear Antigen/metabolism , Propionates/therapeutic use , Repressor Proteins , Survivin , Tumor Necrosis Factor-alpha/metabolismABSTRACT
Trans-dehydrocrotonin has antiulcerogenic and antitumor activities. A complex of beta-cyclodextrin with dehydrocrotonin was developed to improve the delivery of dehydrocrotonin. Complex in solid state was evaluated using X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA) and scanning electron microscopy (SEM). X-ray diffraction and scanning electron microscopy studies showed that dehydrocrotonin exists in a semicrystalline state in the complexed form with beta-cyclodextrin. Differential scanning calorimetry studies showed the existence of a complex of dehydrocrotonin with beta-cyclodextrin. The thermal gravimetric analysis studies confirmed the differential scanning calorimetry results of the complex. Free dehydrocrotonin and the dehydrocrotonin/beta-cyclodextrin inclusion complex were assayed in freshly isolated rat hepatocytes and in V79 cells. Cytotoxicity was determined using nucleic acid content, methylthiazoletetrazolium (MTT) reduction and neutral red uptake assays. In all assays, there was a large reduction (3.5-16.1-fold) in the cytotoxicity of dehydrocrotonin in hepatocytes when complexed with beta-cyclodextrin, whereas for V79 cells the decrease in cytotoxicity was 1.7- and 1.87-fold for MTT reduction and nucleic acid content assays, respectively. The lower cytotoxicity of the dehydrocrotonin/beta-cyclodextrin complex compared to free dehydrocrotonin in rat hepatocytes and V79 cells suggests that such a complex may be useful for the administration of dehydrocrotonin in vivo.
Subject(s)
Diterpenes, Clerodane/pharmacology , Fibroblasts/drug effects , Hepatocytes/drug effects , beta-Cyclodextrins/pharmacology , Animals , Calorimetry, Differential Scanning , Cell Line , Cell Survival/drug effects , Cells, Cultured , Diterpenes, Clerodane/chemistry , Dose-Response Relationship, Drug , Fibroblasts/cytology , Fibroblasts/metabolism , Hepatocytes/cytology , Hepatocytes/metabolism , Inhibitory Concentration 50 , Male , Microscopy, Electron, Scanning , Nucleic Acids/metabolism , Rats , Rats, Wistar , Thermogravimetry , X-Ray Diffraction , beta-Cyclodextrins/chemistryABSTRACT
The effects of beta-cyclodextrin (betaCD) inclusion complexation on the ability of violacein to prevent gastric ulceration in mice were studied. Violacein-betaCD inclusion complexes were prepared in 1:1 and 1:2 molar ratios and analysed by differential scanning calorimetry and powder X-ray diffractometry. Violacein previously administered orally at 10 mg/kg significantly reduced indomethacin-induced gastric lesions, as well as 100 mg/kg of cimetidine (positive control). However, betaCD complexation in both molar ratios significantly potentiated the protective action of violacein. In the HCl--ethanol-induced gastric ulcer model, violacein and the 1:2 inclusion complex (10 mg/kg, p.o.) inhibited gastric damage by almost 85%, whereas a 63% reduction was observed for the positive control, lansoprazole, at 30 mg/kg. In contrast, treatment with the 1:1 inclusion complex resulted in almost total disappearance of the antiulcer activity in this model. No significant changes in stress-induced gastric injury were found. In addition, the 1:2 inclusion complex improved the antilipoperoxidant activity of violacein in rat liver cells exposed to t-butyl hydroperoxide, whereas the 1:1 complex was less active than violacein. In summary, the 1:2 betaCD inclusion complex has gastroprotective properties similar to or higher than that of violacein. An increase in mucosal defensive mechanisms and protection against peroxidative damage might be involved.
Subject(s)
Anti-Ulcer Agents/pharmacology , Cyclodextrins/pharmacology , Indoles/pharmacology , Animals , Cells, Cultured , Chemistry, Pharmaceutical , Cimetidine/pharmacology , Disease Models, Animal , Ethanol/adverse effects , Hepatocytes/drug effects , Hydrochloric Acid/adverse effects , Indomethacin/adverse effects , Indomethacin/antagonists & inhibitors , Lipid Peroxidation/drug effects , Male , Malondialdehyde/metabolism , Mice , Rats , Rats, Wistar , Stomach Ulcer/chemically induced , Stomach Ulcer/drug therapy , Stomach Ulcer/prevention & control , Stress, Physiological/physiopathology , tert-Butylhydroperoxide/adverse effectsABSTRACT
Violacein, a pigment isolated from Chromobacterium violaceum, has been reported to have multiple biological activities including in vitro antitumor effects. Certain anticancer agents are known to induce apoptosis in human tumor cell lines. In this work, our aim was to investigate the effectiveness of violacein/beta-cyclodextrin (beta-CD)-containing systems to produce lethal effects in the human promyelocytic leukemia cell line HL60. Using the MTT tetrazolium reduction test, IC(50) for the inclusion complexes (1:1 and 1:2 violacein:beta-CD molar ratios) and violacein alone were less than 1 microM. Violacein and violacein/beta-CD complexes were able to induce NBT reduction. Moreover, by using the Feulgen reaction, all the compounds were found to trigger apoptosis in HL60 cells, inducing around 35% of DNA fragmentation, as analyzed through the diphenylamine assay. In addition, caspases seem to play an important role in the activation of the executioner phase of apoptosis induced by violacein and its derivatives.
