During 7,12-dimethylbenz[a]anthracene Research Articles

Genistein anticancer efficacy during induced oral squamous cell carcinoma: an experimental study

BackgroundAbout 7 million people die from various types of cancer every year representing nearly 12.5% of deaths worldwide. This fact raises the demand to develop new, effective anticancer, onco-suppressive, and chemoprotective agents for the future fighting of cancers. Genistein exhibits pleiotropic functions in cancer, metabolism, and inflammation. It functions as an antineoplastic agent through its effect on the cell cycle, apoptotic processes, angiogenesis, invasion, and metastasis.Aim of the studyThe current study aimed to study the genistein onco-suppressive effects during 7,12-dimethylbenz[a]anthracene (DMBA)-induced oral carcinogenesis in hamsters’ buccal pouch utilizing flow cytometry analysis (FMA), as a fast-diagnosing tool, in addition to the histopathology.Material and methodsThe buccal mucosa of adult male Syrian hamsters was painted with paraffin oil only (group 1), DMBA mixed in mineral oil (group 2), or orally administrated genistein along with painting DMBA (group 2B). The buccal mucosa was utilized for flow cytometric analysis and histopathological examination.ResultsGrossly, DMBA-induced carcinogenesis started at the 9th week. Progressive signs appeared in the following weeks reaching to large ulcerative oral masses and exophytic nodules at the 21st week. Histologically, invasive well-differentiated oral squamous cell carcinoma (OSCC) appeared in the underlying tissues from the 12th week, showing malignant criteria. Genistein had delayed clinicopathological change, which started 6 weeks later, than the DMBA-painted hamsters, as mild epithelial dysplastic changes. This became moderate during the last 6 weeks, without dysplastic changes. Flow cytometry revealed that DMBA led to considerable variation in DNA proliferation activity, aneuploid DNA pattern, in 47.22% of hamsters and significantly raised the S-phase fragment (SPF) values, which drastically reduced after genistein treatment.ConclusionTaken together, genistein could be employed as an onco-suppressive agent for carcinogenesis. Moreover, FMA could be used as an aiding fast tool for diagnosis of cancer.

D-carvone attenuates biochemical and molecular expression via oncogenic signaling in aryl hydrocarbon-induced hamster mucosal carcinogenesis

Background: Chemo prevention through nutritional constituents has appeared as an innovative methodology to control the oral cancer incidence. The main target of this research exists to explore the chemopreventive effect of D-carvone by way of biochemical and molecular prototype during 7,12-dimethylbenz[a]anthracene (DMBA)-stimulated hamsters mucosal carcinogenesis. Materials and Methods: Topical application of 0.5% DMBA in liquid paraffin, thrice a week, for 10 weeks well developed oral squamous cell carcinoma in hamsters cheek pouch (HCP). All the same 100% tumor formation was perceived in hamsters induced with DMBA alone, but intragastric administration of D-carvone, at a dose of 10 mg/kg bw, to DMBA-treated hamster totally prevented the formation of oral tumor. Results: D-carvone significantly lessens lipid peroxidation (LPO) by-products and enhanced the status of enzymatic, non-enzymatic antioxidants, and varied the status of Phase I and II xenobiotic enzymes, favoring the secretion of cancer metabolites through downregulation of proliferating cell nuclear antigen and p53 expression during oral tumor hamsters. Conclusion: The nearby study suggests that D-carvone relies on its anti-LPO, antioxidant, xenobiotic metabolic enzymes as well as anti-cell proliferation and induced apoptosis during DMBA-induced hamster oral mucosal carcinogenesis.

Polymethoxyflavones prevent benzo[a]pyrene/dextran sodium sulfate-induced colorectal carcinogenesis through modulating xenobiotic metabolism in ICR mice

Toona sinensis leaf extract (TSL) has been shown to have anti-tumor effects on cancer cell lines. This study aimed to investigate the chemopreventive potential and the underlying mechanism of TSL during 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis.One hundred hamsters were divided into control (n = 30), carcinogenic (n = 20), preventive (n = 42), and therapeutic (n = 8) groups. The animals in carcinogenic and preventive groups were administered reverse osmosis water (carcinogenic group) or TSL (1 g/kg bw) (preventive group) by gavage daily for 4 weeks, and their bilateral pouches were painted with a 0.5% DMBA solution for 4, 9, and 12 weeks. The animals in the therapeutic group were treated with DMBA for 12 weeks prior to TSL administration for 4 weeks. Expression levels of survivin, X chromosome-linked inhibitor of apoptosis (XIAP), proliferating cell nuclear antigen (PCNA), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) proteins were analyzed by immunohistochemistry. Apoptotic activity was examined by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method, cytochrome C, and poly (ADP-ribose) polymerase (PARP).In the preventive group, the results showed significant decreases not only in the incidences of squamous cell carcinoma (SCC) (50%) and epithelial dysplasia (62.5%) but also in the tumor number, tumor volume, tumor burden, and the severity of dysplastic lesions. The down-regulation of survivin, XIAP, PCNA, iNOS, and COX-2 proteins and the increased apoptotic activity indicated anti-proliferative and apoptosis-inducing abilities of TSL on DMBA-induced HBP carcinogenesis.The results suggested that TSL might be a promising candidate for the prevention of oral cancer.

Hesperetin on Cell Surface Glycoconjugates Abnormalities and Immunohistochemical Staining with Cytokeratin in 7,12 Dimethylbenz(a)anthracene Induced Hamster Buccal Pouch Carcinogenesis.

Hesperetin, a naturally occurring citrus flavanone of the bioactive substance, possesses different pharmacological and biochemical activities including anti-cancer and anti-oxidants effect. The aim of the study to investigate that hesperetin on abnormalities of glycoconjugates (protein bound hexose, hexosamine, total sialic acid and fucose), histology (PAS staining) and immunoexpression of cytokeratin during 7,12-dimethylbenz(a)anthracene (DMBA) induced hamster buccal pouch (HBP) carcinogenesis. Oral tumors were developed in the buccal pouches of male golden Syrian hamsters by topical application of 0.5% DMBA thrice a week for 10weeks and developed morphological alterations depicted as hyperplasia, dysplasia and well-differentiated squamous cell carcinoma formation with noticeable abnormalities of glycoconjugates and cytokeratin. The protective effect of hesperetin against DMBA was evaluated by assessing immunohistochemical expression, histological sections of buccal tissues and the levels of glycoconjugates in the buccal mucosa and plasma were analyzed. Hesperetin administrated orally at a dose of 20mg/kg b.w. to hamsters treated with DMBA, significantly reduced the status of glycoconjugates and cytokeratin to the near normal range. Overall findings accomplished that hesperetin protects cell surface glycoconjugates abnormalities in DMBA induced HBP carcinogenesis.

Tumor Preventive Efficacy of Emodin in 7,12-Dimethylbenz[a]Anthracene-Induced Oral Carcinogenesis: a Histopathological and Biochemical Approach.

The aim of the present study is to focus the chemopreventive potential of Emodin during 7,12-dimethylbenz[a]anthracene (DMBA) induced hamster buccal pouch carcinogenesis. Tumors were developed in the buccal pouches of golden Syrian hamsters by painting with 0.5% DMBA thrice a week for 14weeks. The status of lipid peroxidation, antioxidants and detoxification agents were utilized as biochemical endpoints and the expression pattern of apoptotic proteins was employed as molecular endpoints in addition to the histopathological studies, to substantiate the anticancer potential of Emodin. Hamsters treated with DMBA + Emodin revealed mild to moderate precancerous lesions such as hyperplasia and dysplasia whereas 100% tumor formation was noticed in hamsters treated with DMBA alone. Also, Emodin treatment modulated the status of lipid peroxidation, antioxidants, phase I and II detoxification agents and apoptotic proteins in favor of the inhibition/reversal/suppression of the oral tumorigenesis in DMBA treated hamsters. The present study thus concludes that the chemopreventive potential of Emodin relies on its pro-apoptotic and antioxidant efficacy during DMBA induced hamster buccal pouch carcinogenesis.

Chemopreventive effect of Toona sinensis leaf extract on 7,12-dimethylbenz[a]anthracene-induced hamster buccal pouch squamous cell carcinogenesis

ObjectiveToona sinensis leaf extract (TSL) has been shown to have anti-tumor effects on cancer cell lines. This study aimed to investigate the chemopreventive potential and the underlying mechanism of TSL during 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis. MethodsOne hundred hamsters were divided into control (n=30), carcinogenic (n=20), preventive (n=42), and therapeutic (n=8) groups. The animals in carcinogenic and preventive groups were administered reverse osmosis water (carcinogenic group) or TSL (1g/kg bw) (preventive group) by gavage daily for 4 weeks, and their bilateral pouches were painted with a 0.5% DMBA solution for 4, 9, and 12 weeks. The animals in the therapeutic group were treated with DMBA for 12 weeks prior to TSL administration for 4 weeks. Expression levels of survivin, X chromosome-linked inhibitor of apoptosis (XIAP), proliferating cell nuclear antigen (PCNA), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) proteins were analyzed by immunohistochemistry. Apoptotic activity was examined by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method, cytochrome C, and poly (ADP-ribose) polymerase (PARP). ResultsIn the preventive group, the results showed significant decreases not only in the incidences of squamous cell carcinoma (SCC) (50%) and epithelial dysplasia (62.5%) but also in the tumor number, tumor volume, tumor burden, and the severity of dysplastic lesions. The down-regulation of survivin, XIAP, PCNA, iNOS, and COX-2 proteins and the increased apoptotic activity indicated anti-proliferative and apoptosis-inducing abilities of TSL on DMBA-induced HBP carcinogenesis. ConclusionsThe results suggested that TSL might be a promising candidate for the prevention of oral cancer.

Raman spectroscopy detects biomolecular changes associated with nanoencapsulated hesperetin treatment in experimental oral carcinogenesis

Recently it has been shown that Raman spectroscopy possesses great potential in the investigation of biomolecular changes of tumor tissues with therapeutic drug response in a non-invasive and label-free manner. The present study is designed to investigate the antitumor effect of hespertin-loaded nanoparticles (HETNPs) relative to the efficacy of native hesperetin (HET) in modifying the biomolecular changes during 7,12-dimethyl benz(a)anthracene (DMBA)-induced oral carcinogenesis using a Raman spectroscopic technique. Significant differences in the intensity and shape of the Raman spectra between the control and the experimental tissues at 1800–500 cm−1 were observed. Tumor tissues are characterized by an increase in the relative amount of proteins, nucleic acids, tryptophan and phenylalanine and a decrease in the percentage of lipids when compared to the control tissues. Further, oral administration of HET and its nanoparticulates restored the status of the lipids and significantly decreased the levels of protein and nucleic acid content. Treatment with HETNPs showed a more potent antitumor effect than treatment with native HET, which resulted in an overall reduction in the intensity of several biochemical Raman bands in DMBA-induced oral carcinogenesis being observed. Principal component and linear discriminant analysis (PC–LDA), together with leave-one-out cross validation (LOOCV) on Raman spectra yielded diagnostic sensitivities of 100%, 80%, 91.6% and 65% and specificities of 100%, 65%, 60% and 55% for classification of control versus DMBA, DMBA versus DMBA + HET, DMBA versus DMBA + HETNPs and DMBA + HET versus DMBA + HETNPs treated tissue groups, respectively. These results further demonstrate that Raman spectroscopy associated with multivariate statistical algorithms could be a valuable tool for developing a comprehensive understanding of the process of biomolecular changes, and could reveal the signatures of the antitumor response of drugs.

Taurine Regulates Mitochondrial Function During 7,12-Dimethyl Benz[a]anthracene Induced Experimental Mammary Carcinogenesis.

Objectives:The present study was undertaken to determine the modulatory effect of taurine on the liver mitochondrial enzyme system with reference to mitochondrial lipid peroxidation (LPO), antioxidants, major tricarboxylic acid cycle enzymes, and electron transport chain enzymes during 7,12-dimethyl benz[a]anthracene (DMBA) induced breast cancer in Sprague-Dawley rats.Methods:Animals in which breast cancer had been induced by using DMBA (25 mg/kg body weight) showed an increase in mitochondrial LPO together with decreases in enzymic antioxidants (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione-S-transferase (GST)), non-enzymic antioxidants (reduced glutathione (GSH), vitamin C, and vitamin E), in citric acid cycle enzymes (isocitrate dehydrogenase (ICDH), alpha ketoglutarate dehydrogenase (alpha KDH), succinate dehydrogenase (SDH) and malate dehydrogenase (MDH)), and in electron transport chain (ETC) complexes.Results:Taurine (100 mg/kg body weight) treatment decreased liver mitochondrial LPO and augmented the activities/levels of enzymic, and non-enzymic antioxidants, tricarboxylic acid cycle enzymes and ETC complexes.Conclusion:The results of our present study demonstrated the chemotherapeutic efficacy of taurine treatment for DMBA-induced breast carcinomas.

Monitoring the metabolic response to nanoencapsulated silibinin treatment in DMBA-induced oral carcinogenesis using endogenous fluorescence

Autofluorescence spectroscopy is a very sensitive tool for detecting early metabolic response after cancer treatment. The present work aims to investigate the chemopreventive effect of the prepared silibinin-loaded nanoparticles (SILNPs) relative to the efficacy of free silibinin (SIL) for monitoring the changes in the endogenous fluorophore emission and to quantify the metabolic changes in the redox state during 7,12-dimethylbenz[a]anthracene (DMBA) induced hamster buccal pouch (HBP) carcinogenesis using autofluorescence spectroscopy. Significant differences in the autofluorescence spectral signatures between the control and the experimental animals have been noticed under the excitation wavelength at 320 nm with emission ranging from 350–550 nm. The tumor tissues are characterized by a decrease in the emission of collagen, nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD) compared to the control tissues. Further, the optical oxidation–reduction (redox) ratio is a measure of cellular metabolism and can be determined by the relative change in the fluorescence emission intensity of NADH and FAD. The optical redox ratio will provide sufficient information on metabolic changes associated with tumor transformation. The results revealed that a significant decrease in the optical redox ratio is observed in DMBA-induced tumor tissues, which indicates increased metabolic activity compared to the control tissues. Moreover, an oral administration of SIL and its nanoparticulates restored the status of endogenous fluorophore emission and led to a higher redox ratio in the buccal mucosa of DMBA-painted animals. On a comparative basis, treatment with nanoparticulate silibinin was found to be more effective than free silibinin for reducing the formation of squamous cell carcinoma and improving the status of endogenous fluorophore emission to a near normal range in DMBA-induced hamster buccal pouch carcinogenesis. Furthermore, the diagnostic algorithms based on principal component analysis followed by linear discriminant analysis (PC–LDA) achieved an overall diagnostic sensitivity of 96.46% and specificity of 93.64% for separating the control from the experimental groups. The results of this study further suggest that the fluorescence spectroscopic technique in conjunction with PC–LDA has a potential for rapid and sensitive detection of specific metabolic alteration and changes in the endogenous fluorophores in response to anti-cancer drug treatments.

Modulating Effect of Ferulic Acid on NF-kB, COX-2 and VEGF Expression Pattern During 7, 12-Dimethylbenz(a)anthracene Induced Oral Carcinogenesis

Ferulic acid, a natural antioxidant, has the potential to prevent inflammation and to modulate angiogenesis in both in vivo and in vitro models. The present study has investigated the modulating effect of ferulic acid on the expression pattern of COX-2, NF-B and VEGF during 7,12-dimethylbenz(a)anthracene (DMBA) induced hamster buccal pouch carcinogenesis. Over expression of COX-2, NF-B and VEGF was noticed in the oral tumor tissues of hamsters treated with DMBA. Oral administration of ferulic acid at a dose of 40 mg/kg body weight to hamsters treated with DMBA completely prevented the tumor formation and downregulated the expression of COX-2, NF-B and VEGF during DMBA induced oral carcinogenesis. The present results suggest that ferulic acid might have suppressed oral tumor formation by down regulating the expression of COX-2, NF-B and VEGF during DMBA induced oral carcinogenesis.

Raman spectroscopic investigation of the chemopreventive response of naringenin and its nanoparticles in DMBA-induced oral carcinogenesis

Raman spectroscopy is a vibrational spectroscopic technique that can be used to optically probe the biomolecular changes associated with tumor progression. The aim of the present study is to investigate the biomolecular changes in chemopreventive response of prepared naringenin-loaded nanoparticles (NARNPs) relative to efficacy of free naringenin (NAR) during 7,12-dimethyl benz(a)anthracene (DMBA)-induced oral carcinogenesis by Fourier Transform Raman (FT-Raman) spectroscopy. Oral squamous cell carcinoma (OSCC) was developed in the buccal pouch of golden Syrian hamsters by painting with 0.5% DMBA in liquid paraffin three times a week for 14weeks. Raman spectra differed significantly between the control and tumor tissues, with tumors showing higher percentage signals for nucleic acids, phenylalanine and tryptophan and a lower in the percentage of phospholipids. Moreover, oral administration of free NAR and NARNPs significantly increased phospholipids and decreased the levels of tryptophan, phenylalanine and nucleic acid contents. On a comparative basis, NARNPs was found to have a more potent antitumor effect than free NAR in completely preventing the formation of squamous cell carcinoma and in improving the biochemical status to a normal range in DMBA-induced oral carcinogenesis. The present study further suggest that Raman spectroscopy could be a valuable tool for rapid and sensitive detection of specific biomolecular changes in response to chemopreventive agents.

Modulating effects of hesperidin on key carbohydrate-metabolizing enzymes, lipid profile, and membrane-bound adenosine triphosphatases against 7,12-dimethylbenz(a)anthracene-induced breast carcinogenesis

The aim of this study was to document the effect of hesperidin on the key enzyme activities of carbohydrate metabolism, lipid profile, and membrane-bound adenosine triphosphatases (ATPases) during 7,12-dimethylbenz(a)anthracene (DMBA)-induced breast carcinogenesis. Hesperidin has been reported to have multiple biological properties. Breast cancer was induced by single dose of DMBA (20mg/kg body weight (bw)). The results revealed that there was a significant increase in the activities of hexokinase, phosphoglucoisomerase, and aldolase and a concomitant decrease in the activities of glucose-6-phosphatase and fructose-1,6-diphosphatase in cancer-induced animals. The activities of ATPases were found to be decreased both in erythrocyte membrane and in the liver of mammary cancer-bearing animals. The lipid profiles such as total cholesterol, free cholesterol, phospholipids, triglycerides, and free fatty acids significantly increased and in contrast the ester cholesterol in plasma was found to be decreased, whereas it was found to be elevated in the liver of cancer-bearing groups. The altered levels of the above-mentioned biochemical parameters in cancer-bearing animals were significantly ameliorated by the administration of hesperidin at the dosage of 30mg/kg bw for 45days. The histopathological analysis of breast and liver tissues were well supported the modulatory property of hesperidin, and this might be associated with normalizing the gluconeogenesis process, stabilization of cell membranes, and modulation of lipid biosynthesis.

Modulating Effect of Lupeol on the Expression Pattern of Apoptotic Markers in 7, 12-Dimethylbenz(a)anthracene Induced Oral Carcinogenesis

Apoptosis, also known as cell suicide or programmed cell death, removes unwanted and genetically damaged cells from the body. Evasion of apoptosis is one of the major characteristic features of rapidly proliferating tumor cells. Chemopreventive agents inhibit or suppress tumor formation through apoptotic induction in target tissues. The aim of the present study was to investigate the pro-apoptotic potential of lupeol during 7,12-dimethylbenz(a) anthracene (DMBA) induced hamster buccal pouch carcinogenesis. Topical application of 0.5% DMBA three times a week for 14 weeks in the buccal pouches of golden Syrian hamsters resulted in oral squamous cell carcinoma. The expression pattern of apoptotic markers was analyzed using immunohistochemistry (p53, Bcl-2, Bax) and ELISA reader (caspase 3 and 9). In the present study, 100% tumor formation with defects in apoptotic markerexpression pattern was noticed in hamsters treated with DMBA alone. Oral administration of lupeol at a dose of 50 mg/kg bw completely prevented the formation oral tumors as well as decreased the expression p53 and Bcl-2, while increasing the expression of Bax and the activities of caspase 3 and 9. The present study thus indicated that lupeol might inhibit DMBA-induced oral tumor formation through its pro-apoptotic potential in golden Syrian hamsters.

Proapoptotic, Anti-Cell Proliferative, Anti-Inflammatory And Antiangiogenic Potential Of Carnosic Acid During 7,12 Dimethylbenz[A]Anthracene-Induced Hamster Buccal Pouch Carcinogenesis

The present study has investigated the modulating effect of carnosic acid on the expression pattern of cell proliferative (proliferating cell nuclear antigen (PCNA) cyclin D1 and a transcription factor c-fos), apoptotic (p53, Bcl-2, Bax caspase -3 and 9), inflammatory (Nuclear factor kappa B (NFκB) and cyclooxygenase-2 (COX- 2) and angiogenic (vascular endothelial growth factor (VEGF) markers during 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch carcinogenesis. Oral tumors were developed in the hamsters buccal pouches by painting with 0.5% DMBA in liquid paraffin three times a week for 14 weeks. Hundred per cent tumour formation (well-differentiated squamous cell carcinoma) accompanied by deregulation in the above mentioned molecular markers was noticed in hamsters treated with DMBA alone (tumour bearing hamsters). Oral administration of carnosic acid at dose of 10mg/kg bw to hamsters treated with DMBA not only completely prevented the tumour formation, but also corrected the abnormalities in the expression pattern of molecular markers. The present study suggests that carnosic acid might have inhibited the tumour formation by exerting anti-cell-proliferative, anti-inflammatory, anti-angiogenic and apoptotic potential during DMBA-induced hamster buccal pouch carcinogenesis.

Lupeol, A Bioactive Triterpene, Prevents Tumor Formation During 7,12-Dimethylbenz(a)anthracene Induced Oral Carcinogenesis

The oral cancer chemopreventive efficacy of lupeol, a bioactive triterpene, was assessed by monitoring the tumor incidence and using the status of phase I and II xenobiotic metabolizing enzymes, lipid peroxidation and antioxidants as biochemical end points during 7,12-dimethylbenz(a)anthracene (DMBA) induced hamster buccal pouch carcinogenesis. Oral tumors were developed in the buccal pouch of golden Syrian hamsters by painting with 0.5 % DMBA three times a week for 14 weeks. Well differentiated oral squamous cell carcinoma with marked abnormalities in the status of biochemical markers were noticed in hamsters treated with DMBA alone. Oral administration of lupeol at a dose of 50 mg/kg bw completely inhibited the formation of oral tumors and restored the status of biochemical markers during DMBA induced oral carcinogenesis. The present study thus demonstrates the chemopreventive potential of lupeol in DMBA induced oral carcinogenesis. The chemopreventive potential of lupeol is probably due to its antioxidant or free radical scavenging property and modulating effect on phase I and II xenobiotic metabolizing enzymes in favour of the excretion of carcinogenic metabolites during DMBA induced hamster buccal pouch carcinogenesis.

Apigenin prevents deregulation in the expression pattern of cell-proliferative, apoptotic, inflammatory and angiogenic markers during 7,12-dimethylbenz[a]anthracene-induced hamster buccal pouch carcinogenesis

ObjectiveMalignant tumour arises due to abnormal cell proliferation, chronic inflammation, defect in apoptotic pathway and unwanted angiogenesis. The present study has investigated the modulating effect of apigenin on expression pattern of apoptotic (p53, Bcl-2, Bax, Caspase-3 and 9) cell proliferative (PCNA, Cyclin D1, c-fos), angiogenic (VEGF) and inflammatory (NFκB, COX-2) markers during 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch carcinogenesis. Materials and methodsOral squamous cell carcinoma was developed in the buccal pouches of golden Syrian hamsters by painting with 0.5% DMBA three times a week for 14 weeks. Deregulation in the expression of the cell proliferation, apoptosis, inflammation and angiogenesis markers was noticed in hamsters treated with DMBA alone. ResultsOral administration of apigenin at a dose of 2.5mg/kgbw prevented the deregulation of the above mentioned molecular markers in hamsters treated with DMBA. ConclusionOur results thus suggest that apigenin exhibited anti-cell proliferative, anti-inflammatory, anti-angiogenic and apoptotic potential during DMBA-induced hamster buccal pouch carcinogenesis.

Pro-apoptotic and anti-inflammatory potential of andrographolide during 7,12-dimethylbenz[a]anthracene induced hamster buccal pouch carcinogenesis

Objective: Aim of the present study was to investigate the modulating effect of andrographolide on apoptotic and inflammatory markers during 7,12-dimethylbenz[a]anthracene (DMBA) induced hamster buccal pouch carcinogenesis. Methods: Oral tumors were developed in the buccal pouch of golden Syrian hamsters by painting with 0.5% DMBA in liquid paraffin three times a week for 14 weeks. The expression pattern of molecular markers were assayed using immunohistochemistry (p53, Bcl-2 and Bax), ELISA (COX-2) and real-time PCR (NFκB). Results: We noticed 100% tumor formation accompanied by deregulation in the apoptotic and inflammatory markers in the buccal mucosa of hamsters treated with DMBA alone. Oral administration of andrographolide at a dose of 50 mg/kg b.w to hamsters treated with DMBA, not only completely prevented the tumor formation but also modulated the status of above mentioned molecular markers in favor of inhibiting cell proliferation as evidenced by no tumor formation.

Protective Effect of Berberine on Expression Pattern of Apoptotic, Cell Proliferative, Inflammatory and Angiogenic Markers During 7,12-dimethylbenz(a)anthracene Induced Hamster Buccal Pouch Carcinogenesis

Investigation of expression pattern of molecular markers in oral epithelial tissues would help to assess the cell differentiation and proliferation as well as early diagnosis of precancerous and cancerous lesions of the oral cavity. Aim of the present study was to investigate the protective effect of berberine on expression pattern of apoptotic, cell proliferative, inflammatory and angiogenic markers during 7,12-dimethylbenz(a)anthracene (DMBA) induced hamster buccal pouch carcinogenesis. Immunohistochemical staining [p53, Bcl-2, Bax, Proliferating Cell Nuclear Antigen (PCNA) and Vascular Endothelial Growth Factor (VEGF)], Enzyme Linked Immuno Sorbent Assay (ELISA) [c-fos, COX-2, caspase-3 and -9] and Real-Time PCR [Cyclin D1 and NFkappaB] were utilized to assess the expression pattern of molecular markers in DMBA induced hamster buccal pouch carcinogenesis. Over expression of mutant p53, PCNA, Bcl-2 and VEGF were noticed in hamsters treated with DMBA alone. Decreased expression of Bax protein was noticed in hamsters treated with DMBA alone. Increased expression of C-fos, COX-2, NFkappaB and Cyclin D1 and decreased activities of caspase-3 and -9 were also noticed in hamsters treated with DMBA alone. Oral administration ofberberine at a dose of 75 mg kg(-1) b.w. brought back the expression of above mentioned molecular markers to near normal pattern in hamsters treated with DMBA. The present results thus suggest that berberine has potent anti-inflammatory, anti-angiogenic, anti-cell proliferative and apoptosis inducing properties in DMBA induced oral carcinogenesis.

Aberrant expression in multiple components of the transforming growth factor-β1-induced Smad signaling pathway during 7,12-dimethylbenz[a]anthracene-induced hamster buccal-pouch squamous-cell carcinogenesis

Transforming growth factor (TGF)-β1 signaling controls a plethora of cellular processes including tumorigenesis. The TGF-β1 ligand initiates signaling by binding to TGF-βreceptor II (TβRII) and allowing heterodimerization with TGF-βreceptor I (TβRI); thus, TβRI is phosphorylated by TβRII. After phosphorylation, Smad2 and Smad3 heterodimerize with Smad4, and this complex migrates to the nucleus to regulate the expression of specific target genes. However, Smad7 interrupts above signal transduction by preventing phosphorylation of Smad2 or Smad3. The objective of this study was to examine the TGF-β1-induced Smad signaling pathway during 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal-pouch squamous-cell carcinogenesis. Fifty 6-week-old male Syrian golden hamsters were divided into three experimental and two control groups (10 animals in each). Both pouches of each animal in the experimental groups were painted with 0.5% DMBA solution, and both pouches of each animal of one of the control groups were similarly treated with mineral oil; the other control group remained untreated throughout the experiment. Animals from three experimental groups were sacrificed at the end of 3rd, 9th, and 14th-weeks after DMBA treatment, respectively, and animals from two control groups were all sacrificed at 14th-weeks after the treatment. Immunohistochemical staining for TGF-β1, TβRI, TβRII, Smad2-4 and Smad7 were performed. A significant increase in the expression of Smad7 and significant decreases in the expression of TβRII, Smad 2, Smad3 and Smad4 were noted during hamster buccal-pouch carcinogenesis induced by DMBA. Our findings indicate that a disruption in TGF-β1-induced Smad signaling occurs as a result of aberrant expression of multiple components in the TGF-β1 signaling pathway during DMBA-induced hamster buccal-pouch carcinogenesis, leading to loss of TGF-β1 growth-suppressive effects on transformed pouch keratinocytes.

Genistein and daidzein, in combination, protect cellular integrity during 7,12-dimethylbenz[a]anthracene (DMBA) induced mammary carcinogenesis in Sprague-Dawley rats.

The status of glycoconjugates (protein bound hexose, hexosamine, sialic acid and fucose) in plasma or serum serve as potential biomarkers for assessing tumor progression and therapeutic interventions. Aim of the present study was to investigate the protective effect of two major soy isoflavones, genistein and daidzein, in combination on the status of glycoconjugates in plasma, erythrocyte membrane and mammary tissues during 7,12-dimethylbenz[a]anthracene (DMBA) induced mammary carcinogenesis in female Sprague-Dawley rats. A single subcutaneous injection of DMBA (25 mg rat(-1)) in the mammary gland developed mammary carcinoma in female Sprague-Dawley rats. Elevated levels of plasma and mammary tissue glycoconjugates accompanied by reduction in erythrocyte membrane glycoconjugates were observed in rats bearing mammary tumors. Oral administration of genistein + daidzein (20 mg + 20 mg kg(-1) bw/day) to DMBA treated rats significantly (p< 0.05) brought back the status of glycoconjugates to near normal range. The present study thus demonstrated that genistein and daidzein in combination protected the structural integrity of the cell surface and membranes during DMBA-induced mammary carcinogenesis.