Iron is essential for the growth of all living cells. One of the most important intracellular roles of iron is the activation of ribonucleotide reductase, which is indispensible to the production of deoxyribonucleotide necessary for DNA synthesis. Deferoxamine (DFO) is an iron chelating agent and has been known to have an antiproliferative effect in various malignant cells including hepatocellular carcinoma and the effect seems to be related to depletion of iron. This study was undertaken to investigate the effect of DFO on preneoplastic lesions in chemically induced hepatocarcinogenesis. The resistant hepatocyte model was used and Sprague Dawley rats were divided into the following groups; I: normal control, II: carcinogen administered group, III: carcinogen and DFO administered group. Rats were sacrificed at 3 days, 1 week, 2 weeks, 3 weeks, 4 weeks and 8 weeks after partial hepatectomy (PH). DFO (50 mg/kg/day, I.P.) was daily injected from 3 weeks before administration of carcinogen to the time when rats were sacrificed. Hepatic iron content was higher in group II than in group III, especially at 3 days and 1 week after PH. Hyperplastic lesions of resistant hepatocytes were less well developed in group III than in group II. Bromodeoxyuridine labelling indices of oval cells and hyperplastic lesions of resistant hepatocytes were higher in group II than in group III except for rats examined at 3 days after PH. The results suggest that DFO has an antiproliferative effect on preneoplastic lesions in hepatocarcinogenesis and it might be related to reduction of the hepatic iron.
Animal ; Deferoxamine/*pharmacology ; Diethylnitrosamine ; Liver Neoplasms, Experimental/chemically induced/*prevention & control ; Male ; Precancerous Conditions/chemically induced/*prevention & control ; Rats ; Rats, Sprague-Dawley ; Support, Non-U.S. Gov't

The anticarcinogenic effects and mechanisms of the biotechnological drugs of Panax ginseng C.A. Meyer cultivated in Russia, bioginseng, panaxel and panaxel- 5, were studied. Bioginseng was produced from a tissue culture of ginseng root cultured on standard medium, whereas panaxel and panaxel-5 were produced from ginseng tissue root cultures using standard mediums enriched with 2-carboxyethylgermanium sesquioxide and 1-hydroxygermatran-monohydrate respectively. All three ginseng drugs inhibited the development of mammary tumors induced by intramammary injections of N-methyl-N-nitrosourea (MNU) in rats, the development of the brain and spinal cord tumors induced by transplacental administration of N-ethyl-N-nitrosourea (ENU) in rats, and the development of uterine, cervical and vaginal tumors induced by intravaginal applications of 7,12-dimethylbenz(a)anthracene (DMBA) in mice. The ginseng drugs induced the cytotoxic activity of macrophages in mice, enhanced T-lymphocyte rosette formation in guinea pigs exposed to cyclophosphamide, and stimulated the production of thyroid hormones in rats. These mechanisms may contribute to the anticarcinogenic action of the ginseng drugs. The organic germanium compounds present in panaxel and panaxel-5 did not potentiate the anticarcinogenic or immuno- stimulatory effects as much as biogeinseng. Preliminary clinical trials with panaxel and bioginseng were carried out in patients with precancerous lesions of the esophagus and endometrium. Panaxel was found to have a strong therapeutic effect in patients suffering from chronic erosive esophagitis. Bioginseng induced the regression of adenomatous-cystic hyperplasia of the endometrium in some patients. Thus, we conclude that the drugs of ginseng appear to hold considerable promise for future cancer chemoprevention.
Adenocarcinoma/chemically induced/prevention & control ; Adult ; Animal ; Antineoplastic Agents, Phytogenic/*therapeutic use ; Cells, Cultured ; Cervix Neoplasms/chemically induced/prevention & control ; Clinical Trials ; Cytotoxicity Tests, Immunologic ; Disease Models, Animal ; Endometrial Neoplasms/pathology/prevention & control ; Endometrium/pathology ; Esophageal Neoplasms/pathology/prevention & control ; Esophagus/pathology ; Estradiol/blood ; Female ; Fibroadenoma/chemically induced/prevention & control ; Human ; Macrophages, Peritoneal/cytology/immunology ; Male ; Mammary Neoplasms, Experimental/chemically induced/prevention & control ; Mice ; Mice, Inbred C57BL ; Neoplasms, Experimental/chemically induced/*prevention & control ; Nervous System Neoplasms/chemically induced/prevention & control ; Panax/*metabolism ; Precancerous Conditions/pathology/*prevention & control ; Rats ; Tissue Culture ; Uterine Neoplasms/chemically induced/prevention & control ; Vaginal Neoplasms/chemically induced/prevention & control

OBJECTIVETo evaluate the chemopreventive effects of boswellic acid and curcumin on 7,12-dimethyl benzanthracene(DMBA)-induced oral carcinogenesis in the hamster cheek pouch model.

METHODSMale Syrian golden hamsters (6 - 8 weeks old, 80 - 130 g in weight) were randomly divided into seven groups, with group A serving as the untreated negative control. The left cheek pouch of the remaining hamsters was topically treated with 0.5% DMBA in mineral oil three times a week for 6 weeks. They were then randomized to six groups with group B serving as a positive control and receiving no further treatment. Groups C-G were treated topically with 5, 10 mg/L boswellic acid, 5, 10 µmol/L curcumin, or the combination of 5 mg/L boswellic acid and 5 µmol/L curcumin three times per week for 18 weeks. The animals were injected with bromodeoxyuridine intraperitoneally at 50 mg/kg 2 h prior to killing. At the 25 th week all the hamsters were sacrificed and cheek pouch tissue was harvested. One half of the tissue was snap frozen in liquid nitrogen for analysis of arachidonic acid metabolites, and the other half was fixed in 10% phosphate-buffered saline(PBS)-buffered formalin for histopathological examination.

RESULTSSix-weeks of DMBA followed by 18-weeks of topical application of boswellic acid and curcumin, both boswellic acid (5, 10 mg/L) and curcumin (5, 10 µmol/L) significantly inhibited the incidence from 93.8% to 73.9% (P > 0.05), numbers from 2.19 ± 0.98 to 1.13 ± 0.81 (P < 0.01) and size of visible tumors. Microscopically the incidence of squamous cell carcinoma and BrdU index were also significantly suppressed by boswellic acid and curcumin.

CONCLUSIONSBoth boswellic acid and curcumin were effective in preventing oral carcinogenesis in DMBA-induced hamster cheek pouch model.

9,10-Dimethyl-1,2-benzanthracene ; Animals ; Antineoplastic Agents ; therapeutic use ; Bromodeoxyuridine ; Carcinogenesis ; drug effects ; Carcinogens ; Carcinoma, Squamous Cell ; chemically induced ; pathology ; prevention & control ; Cheek ; pathology ; Cricetinae ; Curcumin ; therapeutic use ; Hyperplasia ; Leukotriene B4 ; metabolism ; Male ; Mesocricetus ; Mouth Neoplasms ; chemically induced ; pathology ; prevention & control ; Precancerous Conditions ; chemically induced ; pathology ; prevention & control ; Random Allocation ; Triterpenes ; therapeutic use