The propolis, honey bee hive product, is a folk medicine for treating various ailments. Many important pharmaceutical properties have been ascribed to propolis, including anti-inflammatory, antimicrobial, immunormodulatory and carcinostatic activities. The purpose of this study was to examine the effects of ethanol extracted propolis(EEP) on the tumorigenesis and the growth of splenocytes and macrophages in ICR mice. Topical application of 0.2, 2 or mg/ml of EEP on the back of each mice 30 minutes before the application of 7, 12-dimethylbenz (a)anthracene(DMBA) and 12-O-tetradecanoylphorbol-13-acetate(TPA) inhibited the number of tumors per mouse by 61, 75 or 100%, respectively, and tumor size per mouse was decreased by 37, 75 or 100%, respectively. In 3-methylcholanthrene induced tumorigenesis, topical application of same doses of EEP inhibited the number of tumors per mouse by 19, 60 or 90%, and the tumor size per mouse by 58, 85 or 98%, respectively. Oral administration of mice with EEP at 0.2mg or more per day per mouse for 28days increased pulmonary metastases of the B16F10 melanoma cells in ICR mice by 240%, EEP of 3.75ug/ml or more inhibited the growth of ICR mouse spleen cells significantly(p<0.05), but EEP 0.94ug/ml or less did not affects the growth of the spleen cells in vitro. Caffeic acid phenethyl ester(CAPE), which is derived from the propolis, of 0.94ug/ml or less increased the growth of spleen cells, but at the concentations of 3.75ug/ml or more, decreased the growth of spleen cells. EEP of 3.75-15ug/ml increased the growth of mouse peritoneal macrophages, but at the concentration of 60ug/ml, decreased the growth of the macrophages significantly(p<0.01). And also, CAPE of 0.94ug/ml or less did not affects the growth of the macrophages, but at the concentrations of 3.75ug/ml or more, decreased the growth of the macrophages significantly(p<0.01). DDP or CAPE inhibited the nitric oxide production of mouse peritoneal macrophages in concentration-dependent manner regardless of the number of the macrophages in vitro. These results suggest the possibility that the EEP or CAPE might suppress the immune function by the inhibition of growth and activity of spleen cells and macrophages.
Administration, Oral ; Animals ; Bees ; Carcinogenesis* ; Ethanol ; Honey ; Macrophages* ; Macrophages, Peritoneal ; Medicine, Traditional ; Melanoma ; Methylcholanthrene ; Mice* ; Mice, Inbred ICR ; Neoplasm Metastasis ; Nitric Oxide ; Propolis* ; Spleen

OBJECTIVETo study glycyrrhizin's anticancer effect and its mechanism.

METHODS3-methylcholanthrene were injected into mice's submandibular glands to induce tumor, then transplanted the tumor pieces (1 mm3) to mice. The transplanted tumors were measured, and flow cytometry analysis and cytomorphology observation were conducted.

RESULTSGlycyrrhizin (GL) inhibited the transplanted mandibular gland fibro-sarcoma of mice and the suitable GL dose for inhibiting fibrosarcoma of mice was 1.61 mg per 20 g weight. The GL dose below 3.22 mg per 20 g weight didn't produce remarkable toxicity and side effects. GL induced cytomorphological changes of tumor cells and enhanced immunosuppression of macrophage on fibrosarcoma. The result of flow cytometry showed that tumor cell counts of GL1 and GL2 groups increased remarkably in DNA synthetic prophase, and decreased in DNA synthetic phase.

CONCLUSIONGL can inhibit transplanted mandibular gland fibro-sarcoma of mice. The anticancer mechanism of GL may be acting on related enzymes with phagocytosis. The result of flow cytometry showed that the shift of fibrosarcoma cells from G1 phase to S phase was blocked. This suggests that the anticancer action of GL is related to its inhibition of ribonucleotide reductase, a rate-limiting enzyme in DNA synthesis.

Animals ; Antineoplastic Agents ; pharmacology ; DNA, Neoplasm ; biosynthesis ; Fibrosarcoma ; chemically induced ; pathology ; Glycyrrhizic Acid ; pharmacology ; Macrophages ; physiology ; Male ; Methylcholanthrene ; Neoplasm Transplantation ; Phagocytosis

BACKGROUND: The activity of drug metabolizing enzymes and the modulation of their expression by inducers in the skin are the key factors for understanding of pharmacological and toxic effects of topically applied drugs. The role of these enzymes is of major importance, as they may contribute to determine the steady-state levels of biologically active substances. 3-Methylcholanthrene and all-trans- retinoic acid have been known to be inducers of the drug metabolizing enzymes. And all-trans- retinoic acid has many biological actions including anti-cancer effects. OBJECTIVE: The purpose of this study was to evaluate the effect of all-trans-retinoic acid on inducing the expression and modulation of genetic polymorphism of drug metabolizing enzymes as well as to estimate the role of all-trans-retinoic acid in carcinogenesis and drug interactions. METHODS: We analyzed the activities of CYP1A1(Cytochrome P450 1Al), NADPH cytochrome P450-reductase, UGT1 and GST after administration of 3-methylcholanthrene and all-trans-retinoic acid to the Sprague-Dawley male rats. We observed the inducible gene expression of CYP1A1, UGT1, GSTJt by RT-PCR and the genetic polymorphism of CYP1A1, UGT1, GSTK by PCR. RESULTS: 1. The expression of CYP1A1, NADPH cytochrome P450-reductase, UGT1 and GST was induced by 3-methylcholanthrene and all-trans-retinoic acid. That of NADPH cytochrome P450-reductase and UGT1 is pronouncedly enhanced by all-trans- retinoic acid. 2. The effects of 3-methylcholanthrene and all-trans-retinoic acid on inducing the expression of CYP1A1 and UGT1 correlated with an increase of mRNA expression levels of CYP1A1 and UGT1. The modulation of mRNA expression levels of GST was downregulated by all-trans-retinoic acid. 3. The genetic polymorphism of CYP1A1 was induced by 3-methylcholanthrene and all-trans- retinoic acid, and that of GSTM1 was not affected by the inducers. The induction of genetic polymorphism of GST was down regulated by all-trans-retinoic acid. CONCLUSION: 3-Methylcholanthrene and all-trans-retinoic acid modulate the inducible expression and genetic polymorphism of drug metabolizing enzymes differentially. All-trans-retinoic acid can modulate the metabolism of procarcinogen such as 3-methylcholanthrene by inducing drug metabolizing enzymes. Furthermore, the elucidation of the molecular mechanisms underlying the regulation of drug metabolizing enzymes by 3-methylcholanthrene, all-trans-retinoic acid and other drugs could help to understand their respective roles in drug interactions and carcinogenesis.
Animals ; Carcinogenesis ; Cytochrome P-450 CYP1A1 ; Cytochromes ; Drug Interactions ; Gene Expression* ; Humans ; Male ; Metabolism ; Methylcholanthrene ; NADP ; Polymerase Chain Reaction ; Polymorphism, Genetic ; Rats* ; Rats, Sprague-Dawley ; RNA, Messenger ; Skin* ; Tretinoin*

OBJECTIVETo explore the pathogenesis of tumors by blocking the normal differentiation process of stem cells.

METHODSBone marrow mesenchymal stem cells (BMSCs) from rats were isolated, cultured and purified by whole bone marrow adherence method. The rat BMSCs were induced to differentiate into adipocytes with dexamethasone, insulin and indomethacin. Blockage of the differentiation process was induced by 3-methylcholanthrene (3-MC).

RESULTSThe differentiation experiment showed that at 30 days after the induction, oil red O staining-positive cells occurred with increased intracytolasmic lipid droplets, characteristic for adipocytes. The differentiation blockage experiment showed that at 30 days after induction, the deposits of oil red O staining-cytoplasmic lipid droplets was significantly reduced, indicating that the blocked cells were adipocytes, but not fully differentiated. Morphological identification showed that cell contact inhibition disappeared, abnormal cell nuclei, increased number of micronucleus aberration and karyotype abnormalities, indicating that malignant transformation of the stem cells occurred after the differentiation blockage.

CONCLUSIONSThe results of this study show a blockage of the differentiation of that stem cells at the intermediate phase, and a tendency of malignant transformation of the stem cells. The results of our study provide new evidence that cancer stem cells may be originated by suppression of stem cell differentiation.

Adipocytes ; cytology ; Animals ; Bone Marrow Cells ; cytology ; drug effects ; Cell Differentiation ; drug effects ; Cell Transformation, Neoplastic ; Cells, Cultured ; Dexamethasone ; pharmacology ; Drug Combinations ; Female ; Indomethacin ; pharmacology ; Insulin ; pharmacology ; Mesenchymal Stromal Cells ; cytology ; drug effects ; Methylcholanthrene ; pharmacology ; Rats ; Rats, Wistar

OBJECTIVETo investigate the expression of two inflammation related enzymes - cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) during the experimental rat lung carcinogenesis.

METHODSEighty Wistar rats were instilled with 3-methylcholanthrene (MCA) and diethylinitrosamine (DEN) into the left lobar branchus to induce lung squamous cell carcinoma. To obtain specimen in every pathological phase during the carcinogenesis, these rats were sacrificed at different intervals. The expression of COX-2 and iNOS in every pathological phase during the carcinogenesis were examined by immunohistochemical method. The immunohistochemical scores (IHS) were calculated by combining an estimate of the percentage of immunoreactive cells with that of the stain intensity.

RESULTS155 specimens of every pathological phase during the carcinogenesis showed: hyperplasia 14, squamous metaplasia 25, dysplasia 33, carcinoma in situ 12, infiltrating carcinoma 54 and metastasis 17. Inflammation and elevated expressions of COX-2 and iNOS were shown in the precancerous lesions. The COX-2 IHS was significantly increased in dysplasia, carcinoma in situ and metastasis (P < 0.01, P < 0.05, P < 0.01 respectively). The iNOS IHS significantly increased in hyperplasia and metastasis (P < 0.05, P < 0.01 respectively). There was a positive correlation between the expression of COX-2 and iNOS (gamma = 0.601 6, P < 0.001).

CONCLUSIONCOX-2 and iNOS, two inflammation related enzymes, playing important roles in the carcinogenesis of MCA and DEN, induce rat lung squamous cell carcinoma as well as its metastasis. The relation between inflammation and carcinogenesis may partly be explained by the elevated expression of these two enzymes. Nonsteroidal antiinflammatory drug (COX-2 inhibitors) and iNOS inhibitors may possess antitumor activities because of their prevention of bronchial dysplasia, carcinogenesis and metastasis.

Animals ; Carcinogens ; adverse effects ; Carcinoma, Squamous Cell ; chemically induced ; enzymology ; pathology ; Cyclooxygenase 2 ; Female ; Immunohistochemistry ; methods ; Isoenzymes ; biosynthesis ; Lung Neoplasms ; chemically induced ; enzymology ; pathology ; Male ; Methylcholanthrene ; adverse effects ; Neoplasms, Experimental ; chemically induced ; enzymology ; pathology ; Nitric Oxide Synthase ; biosynthesis ; Nitric Oxide Synthase Type II ; Prostaglandin-Endoperoxide Synthases ; biosynthesis ; Rats ; Rats, Wistar

OBJECTIVETo investigate the dynamic expression and its relation of gelatinase A (MMP-2), its natural inhibitor (TIMP-2) and DNA index (DI) changes during carcinogenesis, invasion and metastasis in Wistar rats.

METHODSSquamous cell carcinoma of lung was induced with 3-methylcholanthrene (MCA) and diethyinitrosamine (DEN) in iodized oil by left intra-bronchial instillation in 80 Wistar rats. Immrno histochemistay (IHC) and in situ hybridigation were used in the monitor of MMP-2, TIMP-2 proteins and mRNA expression during invasion and metastasis of lung cancer in these rats, DNA index (DI) value was measured by guantitatove image analysis on feulgen stained sections.

RESULTSAlong with the carcinogenis, the average poritive MNP-2 and TIMP-2 expressions increased, with positive rates of 8.5% - 85.7% and 6.4% - 35.7%. DI value also underwent the same changes (1.47 +/- 0.54) - (2.87 +/- 0.55). The difference of MMP-2 expression in carcinoma in situ versus early carcinoma and early carcinoma versus metastatic carcinoma are statistically significant (P < 0.05). Companing lung carcinome, the contrel group and non-cancerous lesions, the elevation of MNP-2 and TIMP-2 expressions were also sigmificant (P < 0.01). The DI elevation in carcinoma in situ and dysplasia were obviously significant (P < 0.05). Meanwhile a negative relation was noted in TINP-2 and MMP-2 expressions during carcinogenesis. There was a positive relation between MMP-2 expression and DNA poikiloidy (P < 0.01), which was related to the close relationship between MMP-2 and metastasis in advanced rat lung carcinoma (P < 0.05).

CONCLUSIONThe excess degradation and disruption of basement membranes by activated MMP-2 may be a key step in inducing lung cancer invasion and metastasis. The imbalance between MMP and TIMP may be a critical factor which affects biologic behavior of lung carcinogenesis, invasion and metastasis.

Alkylating Agents ; toxicity ; Animals ; Carcinoma, Squamous Cell ; chemically induced ; genetics ; pathology ; Diethylnitrosamine ; toxicity ; Female ; Gene Expression Regulation, Neoplastic ; Lung ; drug effects ; metabolism ; pathology ; Lung Neoplasms ; chemically induced ; genetics ; pathology ; Male ; Matrix Metalloproteinase 2 ; genetics ; metabolism ; Methylcholanthrene ; toxicity ; Neoplasm Invasiveness ; Neoplasm Metastasis ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Wistar ; Tissue Inhibitor of Metalloproteinase-2 ; genetics ; metabolism

OBJECTIVETo find out the anticancer effect of Indigofera aspalathoides (I. aspalathoides) on 20-methylcholanthrene induced fibrosarcoma in rats.

METHODSFibrosarcoma was induced in Wistar strain male albino rats by 20-methylcholanthrene. Intraperitoneous (i.p.) administration of 250 mg/kg body weight/day of aqueous extract of I. aspalathoides for 30 d effectively suppressed chemically induced tumors. Parameters such as body weight, liver and kidney weight, tumor weight, mean survival time, behavioral changes, blood glucose, blood glycogen and marker enzymes such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), acid phosphatase (ACP) and 5'-nucleiotidase (5'-NT) in serum, liver and kidney and lipid profiles such as total cholesterol, phospholipids, free fatty acids in liver and kidney of control and experimental animals were studied.

RESULTSFibrosarcoma bearing animals were ferocious and anxious. The mean survival time was found to increase after the treatment. The body weights were significantly decreased (P<0.001) in group II fibrosarcoma animals which steadily increased after the treatment with I. aspalathoides. The liver and kidney weights were significantly increased whereas the tumor weights decreased as compared to the weights in untreated fibrosarcoma bearing rats. The blood glucose and the liver and kidney glycogen levels were found to decrease significantly (P<0.001) in group II animals. Elevated activities of marker enzymes were observed in serum, liver and kidney of fibrosarcoma bearing Group II animals which were normalize after I. aspalathoides treatment. In the liver and kidney of Group II animals the total cholesterol increased whereas the phospholipids and free fatty acid levels decreased (P<0.001) which were normalized after treatment.

CONCLUSIONSThe treatment by I. aspalathoides on fibrosarcoma bearing rats has improved the levels of various parameters indicating its antiproliferative and anticancer activity.

Animals ; Antineoplastic Agents ; pharmacology ; Chemoprevention ; Fibrosarcoma ; drug therapy ; pathology ; Indigofera ; chemistry ; Kidney ; drug effects ; pathology ; Liver ; drug effects ; pathology ; Liver Neoplasms, Experimental ; chemically induced ; pathology ; prevention & control ; Male ; Methylcholanthrene ; Phytotherapy ; methods ; Plant Extracts ; pharmacology ; Plant Leaves ; chemistry ; Plant Stems ; chemistry ; Rats ; Rats, Wistar ; Seeds ; chemistry