Emodin-induced hepatotoxicity is enhanced by 3-methylcholanthrene through activating aryl hydrocarbon receptor and inducing CYP1A1 in vitro and in vivo.

BACKGROUND & AIMS: Polygonum multiflorum Thunb. (PMT) is the most common traditional Chinese medicine used to treat multiple diseases, and the hepatotoxicity caused by PMT has made great concern around world. Recent results showed that emodin is the potential toxic components of PMT, but the molecular mechanisms of emodin on liver toxicity remain to be elucidated. METHODS: Evaluation of parent- and metabolite-induced cytotoxicity in emodin were compared in L02 cells and mouse model from the perspective of drug metabolizing enzymes. The effect and mechanism of emodin-induced hepatotoxicity were analyzed using electrophoretic mobility shift, promoter reporter, and high content screening. RESULTS: We showed that emodin treatment (360 mg/kg in mice, 50 µM in L02 cells) induced hepatotoxicity and enhanced reactive oxidative stress (ROS) level. Importantly, emodin-induced ROS accumulation and hepatotoxicity were attenuated in the condition of CH223191, a selective inhibitor of aryl hydrocarbon receptor (AhR), and aggravated by 3-methylcholanthrene, a selective activator of AhR. Interestingly, we performed the study on ROS mediated ER stress and mitochondrial dysfunction in emodin-induced hepatotoxicity, the results showed that emodin can decrease MMP and trigger ER stress with Ca2+ overloading and the expression of ATF4 increasing, further resulted with increased apoptosis in L02 cells and mice mortality rate, while the changes were alleviated by CH223191. Furthermore, the 5-hydroxyemodin, a metabolite by emodin through CYP1A2 enzyme, showed more severe hepatotoxicity compared to emodin. CONCLUSIONS: Our results validated that the metabolism of emodin to 5-hydroxyemodin by CYP1A played an important role in the hepatocellular toxicity of emodin and provided evidence that CYP1A1 and AhR could be used to predict and validate patient-specific liver injury of PMT or other herbs containing emodin.

Metformin alters therapeutic effects in the BALB/c tumor therapy model.

BACKGROUND: Despite considerable medical proceedings, cancer is still a leading cause of death. Major problems for tumor therapy are chemoresistance as well as toxic side effects. In recent years, the additional treatment with the antidiabetic drug metformin during chemotherapy showed promising results in some cases. The aim of this study was to develop an in vitro tumor therapy model in order to further investigate the potential of a combined chemotherapy with metformin. METHODS: Cytotoxic effects of a combined treatment on BALB/c fibroblasts were proven by the resazurin assay. Based on the BALB/c cell transformation assay, the BALB/c tumor therapy model was established successfully with four different and widely used chemotherapeutics from different categories. Namely, Doxorubicin as a type-II isomerase inhibitor, Docetaxel as a spindle toxin, Mitomycin C as an alkylating agent and 5-Fluorouracil as an antimetabolite. Moreover, glucose consumption in the medium supernatant was measured and protein expressions were determined by Western Blotting. RESULTS: Initial tests for the combined treatment with metformin indicated unexpected results as metformin could partly mitigate the cytotoxic effects of the chemotherapeutic agents. These results were further confirmed as metformin induced resistance to some of the drugs when applied simultaneously in the tumor therapy model. Mechanistically, an increased glucose consumption was observed in non-transformed cells as well as in the mixed population of malignant transformed cell foci and non-transformed monolayer cells, suggesting that metformin could also increase glucose consumption in transformed cells. CONCLUSION: In conclusion, this study suggests a cautious use of metformin during chemotherapy. Moreover, the BALB/c tumor therapy model offers a potent tool for further mechanistic studies of drug-drug interactions during cancer therapy.

PD-1-specific "Blocking" antibodies that deplete PD-1+ T cells present an inconvenient variable in preclinical immunotherapy experiments.

Therapeutic antibodies blocking PD-1-/PD-L1 interaction have achieved remarkable clinical success in cancer. In addition to blocking a target molecule, some isotypes of antibodies can activate complement, NK cells or phagocytes, resulting in death of the cell expressing the antibody's target. Human anti-PD-1 therapeutics use antibody isotypes designed to minimize such antibody-dependent lysis. In contrast, anti-PD-1 reagents used in mice are derived from multiple species, with different isotypes, and are not engineered to reduce target cell death: few studies analyze or discuss how antibody species and isotype may impact data interpretation. We demonstrate here that anti-PD-1 therapy to promote activation and proliferation of murine PD-1-expressing CD8 T cells sometimes led instead to a loss of antigen specific cells. This phenomenon was seen in two tumor models and a model of virus infection, and varied with the clone of anti-PD-1 antibody. Additionally, we compared competition among anti-PD-1 clones to find a combination that allows detection of PD-1-expressing cells despite the presence of blocking anti-PD1 antibodies in vivo. These data bring attention to the possibility of unintended target cell depletion with some commonly used anti-mouse PD-1 clones, and should provide a valuable resource for the design and interpretation of anti-PD-1 studies in mice.

Pulmonary toxicity and lung tumorigenic potential of surrogate metal oxides in gas metal arc welding-stainless steel fume: Iron as a primary mediator versus chromium and nickel.

In 2017, the International Agency for Research on Cancer classified welding fumes as "carcinogenic to humans" (Group 1). Both mild steel (MS) welding, where fumes lack carcinogenic chromium and nickel, and stainless steel (SS) increase lung cancer risk in welders; therefore, further research to better understand the toxicity of the individual metals is needed. The objectives were to (1) compare the pulmonary toxicity of chromium (as Cr(III) oxide [Cr2O3] and Cr (VI) calcium chromate [CaCrO4]), nickel [II] oxide (NiO), iron [III] oxide (Fe2O3), and gas metal arc welding-SS (GMAW-SS) fume; and (2) determine if these metal oxides can promote lung tumors. Lung tumor susceptible A/J mice (male, 4-5 weeks old) were exposed by oropharyngeal aspiration to vehicle, GMAW-SS fume (1.7 mg), or a low or high dose of surrogate metal oxides based on the respective weight percent of each metal in the fume: Cr2O3 + CaCrO4 (366 + 5 µg and 731 + 11 µg), NiO (141 and 281 µg), or Fe2O3 (1 and 2 mg). Bronchoalveolar lavage, histopathology, and lung/liver qPCR were done at 1, 7, 28, and 84 days post-aspiration. In a two-stage lung carcinogenesis model, mice were initiated with 3-methylcholanthrene (10 µg/g; intraperitoneal; 1x) or corn oil then exposed to metal oxides or vehicle (1 x/week for 5 weeks) by oropharyngeal aspiration. Lung tumors were counted at 30 weeks post-initiation. Results indicate the inflammatory potential of the metal oxides was Fe2O3 > Cr2O3 + CaCrO4 > NiO. Overall, the pneumotoxic effects were negligible for NiO, acute but not persistent for Cr2O3 + CaCrO4, and persistent for the Fe2O3 exposures. Fe2O3, but not Cr2O3 + CaCrO4 or NiO significantly promoted lung tumors. These results provide experimental evidence that Fe2O3 is an important mediator of welding fume toxicity and support epidemiological findings and the IARC classification.

Osteotoxicity of 3-methylcholanthrene in fish.

Many chemicals produced by human activities end up in the aquatic ecosystem causing adverse developmental and reproductive effects in aquatic organisms. There is evidence that some anthropogenic chemicals disturb bone formation and skeletal development but the lack of suitable in vitro and in vivo systems for testing has hindered the identification of underlying mechanisms of osteotoxicity. Several fish systems - an in vitro cell system to study extracellular matrix mineralization and in vivo systems to evaluate bone formation and skeletogenesis - were combined to collect data on the osteotoxic activity of 3-methylcholanthrene (3-MC), a polycyclic aromatic hydrocarbon. Anti-mineralogenic effects, increased incidence of skeletal deformities and reduced bone formation and regeneration were observed in zebrafish upon exposure to 3-MC. Pathway reporter array revealed the role of the aryl hydrocarbon receptor 2 (Ahr2) in the mechanisms underlying 3-MC osteotoxicity in mineralogenic cell lines. Analysis of gene expression in zebrafish larvae confirmed the role of Ahr2 in the signaling of 3-MC toxicity. It also indicated a possible complementary action of the pregnane X receptor (Pxr) in the regulation of genes involved in bone cell activity and differentiation but also in xenobiotic metabolism. Data reported here demonstrated the osteotoxicity of 3-MC but also confirmed the suitability of fish systems to gain insights into the toxic mechanisms of compounds affecting skeletal and bone formation.

Creatine supplementation with methylglyoxal: a potent therapy for cancer in experimental models.

The anti-cancer effect of methylglyoxal (MG) is now well established in the literature. The main aim of this study was to investigate the effect of creatine as a supplement in combination with MG both in vitro and in vivo. In case of the in vitro studies, two different cell lines, namely MCF-7 (human breast cancer cell line) and C2C12 (mouse myoblast cell line) were chosen. MG in combination with creatine showed enhanced apoptosis as well as higher cytotoxicity in the breast cancer MCF-7 cell line, compared to MG alone. Pre-treatment of well-differentiated C2C12 myotubes with cancerogenic 3-methylcholanthrene (3MC) induced a dedifferentiation of these myotubes towards cancerous cells (that mimic the effect of 3MC observed in solid fibro-sarcoma animal models) and subsequent exposure of these induced cancer cells with MG proved to be cytotoxic. Thus, creatine plus ascorbic acid enhanced the anti-cancer effects of MG. In contrast, when normal C2C12 muscle cells or myotubes (mouse normal myoblast cell line) were treated with MG or MG plus creatine and ascorbic acid, no detrimental effects were seen. This indicated that cytotoxic effects of MG are specifically limited towards cancer cells and are further enhanced when MG is used in combination with creatine and ascorbic acid. For the in vivo studies, tumors were induced by injecting Sarcoma-180 cells (2 × 10(6) cells/mouse) in the left hind leg. After 7 days of tumor inoculation, treatments were started with MG (20 mg/kg body wt/day, via the intravenous route), with or without creatine (150 mg/kg body wt/day, fed orally) and ascorbic acid (50 mg/kg body wt/day, fed orally) and continued for 10 consecutive days. Significant regression of tumor size was observed when Sarcoma-180 tumor-bearing mice were treated with MG and even more so with the aforesaid combination. The creatine-supplemented group demonstrated better overall survival in comparison with tumor-bearing mice without creatine. In conclusion, it may be stated that the anti-cancer effect of MG is enhanced by concomitant creatine supplementation, both in chemically transformed (by 3MC) muscle cells in vitro as well as in sarcoma animal model in vivo. These data strongly suggest that creatine supplementation may gain importance as a safe and effective supplement in therapeutic intervention with the anti-cancer agent MG.

Inhibition of Soluble Tumor Necrosis Factor Prevents Chemically Induced Carcinogenesis in Mice.

TNF is a potent promoter of carcinogenesis and potentially important target for cancer prevention. TNF is produced as functionally distinct transmembrane and soluble molecules (tmTNF and sTNF, respectively), but their individual roles in carcinogenesis are unexplored. We investigated the participation of tmTNF and sTNF in chemically induced carcinogenesis in mice. We found that injection of XPro1595, a dominant-negative TNF biologic (DN-TNF) and specific antagonist of sTNF, decreased tumor incidence and growth, and prolonged survival of 3-methylcholanthrene (MCA)-injected mice. Similar results were obtained following the exclusion of both TNF forms by either TNF-receptor 2-Fc fusion protein (TNFR2-Fc) treatment or TNF gene deletion. In addition, gene deletion of TNFR1, which is preferentially triggered by sTNF, was temporarily blocked, whereas gene deletion of TNFR2, which is preferentially triggered by tmTNF, enhanced MCA-induced carcinogenesis. Concomitantly with carcinogenesis induction, MCA increased circulating IL1α, accumulation of myeloid-derived suppressor cells (MDSC), STAT3 phosphorylation, and immunosuppression in the spleen. In sharp contrast, DN-TNF treatment dramatically decreased IL1α and increased the essential immunoregulatory cytokines IL1ß, IL12p70, and IL17 in the peripheral blood of MCA-injected mice. In addition, MDSC accumulation, STAT3 phosphorylation, and immunosuppression in MCA-injected mice were prevented by DN-TNF treatment, TNFR2-Fc treatment, and/or gene deletion of TNF or TNFR1, but not deletion of TNFR2. These findings reveal that sTNF is both an essential promoter of carcinogenesis and a pivotal regulator of MDSCs, and indicate that sTNF could be a significant target for cancer prevention and therapy. Cancer Immunol Res; 4(5); 441-51. ©2016 AACR.

Adaptations of Arginine's Intestinal-Renal Axis in Cachectic Tumor-Bearing Rats.

Malignancies induce disposal of arginine, an important substrate for the immune system. To sustain immune function, the tumor-bearing host accelerates arginine's intestinal-renal axis by glutamine mobilization from skeletal muscle and this may promote cachexia. Glutamine supplementation stimulates argi-nine production in healthy subjects. Arginine's intestinal-renal axis and the effect of glutamine supplementation in cancer cach-exia have not been investigated. This study evaluated the long-term adaptations of the interorgan pathway for arginine production following the onset of cachexia and the metabolic effect of glutamine supplementation in the cachectic state. Fischer-344 rats were randomly divided into a tumor-bearing group (n = 12), control group (n = 7) and tumor-bearing group receiving a glutamine-enriched diet (n = 9). Amino acid fluxes and net fractional extractions across intestine, kidneys, and liver were studied. Compared to controls, the portal-drained viscera of tumor-bearing rats took up significantly more glutamine and released significantly less citrulline. Renal metabolism was unchanged in the cachectic tumor-bearing rats compared with controls. Glutamine supplementation had no effects on intestinal and renal adaptations. In conclusion, in the cachectic state, an increase in intestinal glutamine uptake is not accompanied by an increase in renal arginine production. The adaptations found in the cachectic, tumor-bearing rat do not depend on glutamine availability.

Crocetin downregulates the proinflammatory cytokines in methylcholanthrene-induced rodent tumor model and inhibits COX-2 expression in cervical cancer cells.

The effect of crocetin (C20H24O4) on methylcholanthrene- (MCA-) induced uterine cervical cancer in mice was studied in this paper. After the mice were treated orally with crocetin, maleic dialdehyde (MDA), polymorphonuclear cells (PMN), interleukin-1ß (IL-1ß), and tumor necrosis factor-α (TNF-α) were examined by ELISA or immunohistochemistry. The inducible nitric oxide synthase (iNOS) activation in HeLa cells was analyzed using fluorescence microscopy for light microscopic examination. The MCA mice showed a significant increase in plasma MDA, PMN, IL-1ß, TNF-α, and nitrates levels. At the same time, the mRNA level of COX-2 in HeLa cells was also significantly increased. These changes were attenuated by crocetin supplementation in the MCA mice. Crocetin supplementation in the MCA mice also showed protection against cervical cancer. These results suggest that crocetin may act as a chemopreventive and an anti-inflammatory agent.

Dehydroepiandrosterone sulfate and cytochrome P450 inducers alleviate fatty liver in male rats fed an orotic acid-supplemented diet.

The effects of the peroxisome proliferator, dehydroepiandrosterone sulfate (DHEAS), and the typical cytochrome P450 (CYP) inducers phenobarbital (PB) and 3-methylcholanthrene (3-MC) on fatty liver were examined in rats. Treating rats with orotic acid caused marked accumulation of lipid droplets in the liver. This effect of orotic acid was almost eradicated by co-treatment with DHEAS and PB. While DHEAS or PB alone also alleviated fatty liver, treatment with 3-MC caused little effect on a reduction in lipid droplets. Histopathological examinations revealed numerous peroxisomes in the liver of rats treated with DHEAS. In addition, a significant increase in the expression on hepatic CYPs was observed in rats the fatty liver of which was attenuated. Regarding other enzymes associated with hepatic fatty acid oxidation, the expression levels of sirtuin 1, sirtuin 6, and carnitine palmitoyltransferase 1 were also upregulated most markedly by treatment with DHEAS alone. Thus, the attenuation in fatty liver observed in the present study is likely due to peroxisome proliferation and the induction of fatty acid-metabolizing enzymes by DHEAS and typical CYP inducers.

Catechins in tea suppress the activity of cytochrome P450 1A1 through the aryl hydrocarbon receptor activation pathway in rat livers.

Polycyclic aromatic hydrocarbons (PAHs) and halogenated aromatic hydrocarbons (HAHs) develop various adverse effects through activation of an aryl hydrocarbon receptor (AhR). The suppressive effects of brewed green tea and black tea on 3-methylcholanthrene (MC)-induced AhR activation and its downstream events were examined in the liver of rats. Ad-libitum drinking of green tea and black tea suppressed MC-induced AhR activation and elevation of ethoxyresorufin O-deethylase activity in the liver, whereas the teas themselves did not induce them. Tea showed a suppressive fashion on the expression of cytochrome P450 1A1 (CYP1A1). Tea suppressed the AhR activation induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) ex vivo. A part of catechins and theaflavins was present in plasma and liver as conjugated and intact forms. The results of this study suggested that active component(s) of tea are incorporated in the liver and suppress the activity of CYP1As through the AhR activation pathway.

Comparison of serum and tissue levels of trace elements in different models of cervical cancer.

Cervical cancer is a leading cause of death by cancer among women worldwide. It is necessary to develop and refine cervical cancer models to more accurately reflect human tumor type. The relevance of cervical cancer to trace element was studied in this paper. By means of quantitative trace element analysis in models and patients with cervical cancer, the tissue and serum levels of trace elements in papillomaviruses-induced cancer models were more similar to that of patients than the levels in models induced by HeLa cell and methylcholanthrene. The results reflect papillomaviruses model most accurately mimic in vivo carcinogenesis of patients with cervical cancer. It will have a superior predictive value over HeLa cell and methylcholanthrene models in pre-clinical trials. The papillomaviruses-induced cervical cancer can provide more reliable models for testing the efficacy of drugs in treating human cancers.

Proteomic profiling of the hypothalamus in a mouse model of cancer-induced anorexia-cachexia.

BACKGROUND: Anorexia-cachexia is a common and severe cancer-related complication but the underlying mechanisms are largely unknown. Here, using a mouse model for tumour-induced anorexia-cachexia, we screened for proteins that are differentially expressed in the hypothalamus, the brain's metabolic control centre. METHODS: The hypothalamus of tumour-bearing mice with implanted methylcholanthrene-induced sarcoma (MCG 101) displaying anorexia and their sham-implanted pair-fed or free-fed littermates was examined using two-dimensional electrophoresis (2-DE)-based comparative proteomics. Differentially expressed proteins were identified by liquid chromatography-tandem mass spectrometry. RESULTS: The 2-DE data showed an increased expression of dynamin 1, hexokinase, pyruvate carboxylase, oxoglutarate dehydrogenase, and N-ethylmaleimide-sensitive factor in tumour-bearing mice, whereas heat-shock 70 kDa cognate protein, selenium-binding protein 1, and guanine nucleotide-binding protein Gα0 were downregulated. The expression of several of the identified proteins was similarly altered also in the caloric-restricted pair-fed mice, suggesting an involvement of these proteins in brain metabolic adaptation to restricted nutrient availability. However, the expression of dynamin 1, which is required for receptor internalisation, and of hexokinase, and pyruvate carboxylase were specifically changed in tumour-bearing mice with anorexia. CONCLUSION: The identified differentially expressed proteins may be new candidate molecules involved in the pathophysiology of tumour-induced anorexia-cachexia.

Timing of antioxidant supplementation is critical in improving anorexia in an experimental model of cancer.

Increased oxidative stress may contribute to cancer anorexia, which could be ameliorated by antioxidant supplementation. methylcholanthrene (MCA) sarcoma-bearing Fisher rats were studied. After tumour inoculation, rats were randomly assigned to standard diet (CTR group, n = 6), or to an antioxidant-enriched diet (AOX group, n = 8). Eight more rats (STD-AOX group) switched from standard to antioxidant diet when anorexia developed. At the end of the study, food intake (FI, g/d), body weight and tumour weight (g) were recorded, and plasma samples were obtained. On day 16, anorexia has appeared only in CTR and STD-AOX animals. At the end of the study, FI in AOX animals was still higher than in the other groups (p = 0.08). No differences in body and tumour weights were observed among groups. However, hydrogen peroxide and interleukin-1ß levels were significantly reduced only in AOX rats. Data obtained suggest that early antioxidant supplementation improves cancer anorexia, ameliorates oxidative stress and reduces inflammation.

Chemopreventive property of Trichosanthes dioica root against 3-methylcholanthrene-induced carcinogenesis in albino mice.

This work reports the chemopreventive property of hydroalcoholic extract of the Trichosanthes dioica root (TDA) against 3-methylcholanthrene (3-MC)-induced carcinogenesis in Swiss albino mice. TDA was administered orally at 2 and 4 mg/kg for 45 days after 24 hours of a single subcutaneous administration of 3-MC (200 µg) in mice. The mice were observed for 15 weeks to record tumor incidence (fibrosarcoma) and survival. After 15 weeks the mice were killed for the evaluation of hematological profiles and hepatic biochemical parameters viz lipid peroxidation, reduced glutathione, glutathione-S-transferase, superoxide dismutase, and catalase. TDA treatment markedly reduced tumor incidence and prolonged the life span of sarcoma-bearing mice compared with 3-MC control mice. Hematological profiles of TDA-treated mice were restored significantly to normal levels. TDA treatment significantly modulated the liver biochemical parameters compared with 3-MC control. Therefore, TDA possesses remarkable cancer chemopreventive efficacy plausibly mediated by multiple mechanisms in Swiss albino mice.

Evaluation of radiogallium-labeled, folate-embedded superparamagnetic nanoparticles in fibrosarcoma-bearing mice.

CONTEXT: Elevated expression of the folate receptor (FR) occurs in many human malignancies. Thus, folate targeting is widely utilized in drug delivery purposes specially using nano-radioactive agents. AIMS: In this work, we report production and biological evaluation of gallium-67 labeled superparamagnetic iron oxide nanoparticles, embedded by folic acid ( 67 Ga-SPION-folate) complex especially in tumor-bearing mice for tumor imaging studies. SETTINGS AND DESIGN: The structure of SPION-folate was confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and foureir transform infrared spectroscopy (FT-IR) analyses. The radiolabeled SPION-folate formation was confirmed by instant thin layer chromatography (ITLC). Tumor induction was performed by the use of poly-aromatic hydrocarbon injection in rodents as reported previously. MATERIALS AND METHODS: [ 67 Ga]-SPION-folate was shown to possess a particle size of ≈ 5-10 nm using instrumental methods followed by ITLC test. Biocompatibility of the compound was investigated using an 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay followed by stability tests and tumor accumulation studies in fibrosarcoma-bearing mice after subcutaneous (s.c.) application. STATISTICAL ANALYSIS USED: All values were expressed as mean ± standard deviation (mean ± SD) and the data were compared using Student t-test. Statistical significance was defined as P<0.05. RESULTS: [ 67 Ga]-SPION-folate was prepared by a modified co-precipitation method possessing a particle size of ≈ 5-10 nm using instrumental methods (>95% radiochemical purity). Biodistribution studies demonstrated tumor:blood, tumor:bone and tumor:muscle ratios of 4.23, 4.98 and 11.54 respectively after 24 h. CONCLUSIONS: Due to the nano-scale size and high-penetrative property of the developed folate-containing nano-complex, this system can be an interesting drug delivery modality with therapeutic applications and folate receptor-targeting behavior, while possessing paramagnetic properties for thermotherapy.

Mediating effects of aryl-hydrocarbon receptor and RhoA in altering brain vascular integrity: the therapeutic potential of statins.

We have demonstrated previously that focal adhesion kinase (FAK)/RhoA alteration by the aryl-hydrocarbon receptor (AhR) agonist 3-methylcholanthrene (3MC) is involved in the antimigratory effects of 3MC in human umbilical vascular endothelial cells. Here, we identified that signaling properties and molecular mechanisms of RhoA/ß-catenin were both implicated in alterations to blood-brain barrier integrity. The mechanisms of action were the down-regulation of integrin, the extracellular matrix, and adherens junction stability. PTEN phosphorylation by 3MC-mediated AhR/RhoA activation increased the proteasomal degradation of ß-catenin through PKCδ/pGSK3ß-mediated ß-catenin phosphorylation; the crucial roles of AhR/RhoA in this process were verified by using gain- or loss-of-function experiments. The decrease in ß-catenin led to decreased expression of fibronectin and α5ß1 integrin. Additionally, protein interactions among FAK, VE-cadherin, vinculin, and ß-actin were simultaneously decreased, resulting in adherens junction instability. Novel functional TCF/LEF1 binding sites in the promoter regions of fibronectin and α5/ß1 integrin were identified by electrophoretic mobility shift and chromatin immunoprecipitation assays. The results indicate that the binding activities of ß-catenin decreased in mouse cerebrovascular endothelial cells treated with 3MC. In addition, simvastatin and pravastatin treatment reversed 3MC-mediated alterations in mouse cerebrovascular endothelial cells by RhoA inactivation, and the in vitro findings were substantiated by an in vivo blood-brain barrier assay. Thus, endothelial barrier dysfunction due to 3MC occurs through AhR/RhoA-mediated ß-catenin down-regulation, which is reversed by simvastatin treatment in vivo.

Estimation of trace elements in mace (Myristica fragrans Houtt) and their effect on uterine cervix cancer induced by methylcholanthrene.

In the present work, trace elemental analysis of mace (Myristica fragrans Houtt) was carried out by the atomic absorption spectrometry technique. The concentrations of various elements analyzed in this medicine were ranked in decreasing order: selenium (Se) > zinc (Zn) > magnesium (Mg) > iron (Fe) > calcium (Ca) > manganese (Mn) > lead (Pb). The concentrations of Mg, Zn, Fe, Mn, Ca, and Se were significantly decreased in serum of methylcholanthrene tumor models (P < 0.001) compared with the control and mace groups. It is consistent with the result of tumor incidence. These trace elements could be directly or indirectly responsible for the antitumor activity of mace. The inorganic elements in this folk remedy can partly account for the antitumor.

Cigarette smoking, coffee drinking, and ingestion of charcoal-broiled beef as potential modifiers of drug therapy and confounders of clinical trials.

A pathway of research is described, leading from the finding of an inhibitory effect of 3-methylcholanthrene on the carcinogenicity of an aminoazo dye, to the induction of drug-metabolizing enzymes by 3-methylcholanthrene, benzo[a]pyrene, and other polycyclic aromatic hydrocarbons, to the demonstration of enhanced drug metabolism in cigarette smokers, coffee drinkers, and people who eat charcoal-broiled beef. The results of these studies indicate that cigarette smoking, coffee drinking, and the ingestion of charcoal-broiled beef (all resulting in exposure to polycyclic aromatic hydrocarbons) can influence the dosing regimen needed for proper drug therapy and are potential confounders of clinical trials with drugs metabolized by polycyclic aromatic hydrocarbon-inducible enzymes.

Antiproliferative role of Indigofera aspalathoides on 20 methylcholanthrene induced fibrosarcoma in rats.

OBJECTIVE: To find out the anticancer effect of Indigofera aspalathoides (I. aspalathoides) on 20-methylcholanthrene induced fibrosarcoma in rats. METHODS: Fibrosarcoma 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. RESULTS: Fibrosarcoma 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. CONCLUSIONS: The treatment by I. aspalathoides on fibrosarcoma bearing rats has improved the levels of various parameters indicating its antiproliferative and anticancer activity.