DMBA-induced Mammary Carcinogenesis Research Articles

Therapeutic silencing of mTOR by systemically administered siRNA-loaded neutral liposomal nanoparticles inhibits DMBA-induced mammary carcinogenesis.

Mammary carcinogenesis possesses great challenges due to the lack of effectiveness of the multiple therapeutic options available. Gene therapy-based cancer treatment strategy provides more targeting accuracy, fewer side effects, and higher therapeutic efficiency. Downregulation of the oncogene mTOR by mTOR-siRNA is an encouraging approach to reduce cancer progression. However, its employment as means of therapeutic strategy has been restricted due to the unavailability of a suitable delivery system. A suitable nanocarrier system made up of 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine (DOPC) has been developed to prevent degradation and for proficient delivery of siRNA. This was followed by in vitro and in vivo anti-breast cancer efficiency analysis of the mTOR siRNA-loaded neutral liposomal formulation (NL-mTOR-siRNA). In our experiment, a profound reduction in MCF-7 cell growth, proliferation and invasion was ascertained following extensive downregulation of mTOR expression. NL-mTOR-siRNA suppressed tumour growth and restored morphological alterations of DMBA-induced breast cancer. In addition, neutral liposome enhanced accumulation of siRNA in mammary cancer tissues facilitating its deep cytosolic distribution within the tumour, which allows apoptosis thereby facilitating its anti-tumour potential. Hence, the current study highlighted the augmented ground for therapies aiming toward cancerous cells to diminish mTOR expression by RNAi in managing mammary carcinoma.

Induced mammary cancer in rat models: pathogenesis, genetics, and relevance to female breast cancer.

Mammary cancer, or breast cancer in women, is a polygenic disease with a complex etiopathogenesis. While much remains elusive regarding its origin, it is well established that chemical carcinogens and endogenous estrogens contribute significantly to the initiation and progression of this disease. Rats have been useful models to study induced mammary cancer. They develop mammary tumors with comparable histopathology to humans and exhibit differences in resistance or susceptibility to mammary cancer depending on strain. While some rat strains (e.g., Sprague-Dawley) readily form mammary tumors following treatment with the chemical carcinogen, 7,12-dimethylbenz[a]-anthracene (DMBA), other strains (e.g., Copenhagen) are resistant to DMBA-induced mammary carcinogenesis. Genetic linkage in inbred strains has identified strain-specific quantitative trait loci (QTLs) affecting mammary tumors, via mechanisms that act together to promote or attenuate, and include 24 QTLs controlling the outcome of chemical induction, 10 QTLs controlling the outcome of estrogen induction, and 4 QTLs controlling the outcome of irradiation induction. Moreover, and based on shared factors affecting mammary cancer etiopathogenesis between rats and humans, including orthologous risk regions between both species, rats have served as useful models for identifying methods for breast cancer prediction and treatment. These studies in rats, combined with alternative animal models that more closely mimic advanced stages of breast cancer and/or human lifestyles, will further improve our understanding of this complex disease.

Salvadora persica attenuates DMBA-induced mammary cancer through downregulation oxidative stress, estrogen receptor expression and proliferation and augmenting apoptosis

Naturally occurring phytochemicals especially polyphenolic compounds have received increasing attention as chemopreventive agents. The chemopreventive potential of the ethanolic extract of Salvadora persica L. fruits SP, (the arak tree or miswak) on 7,12-dimethylbenz (a) anthracene (DMBA)-induced mammary carcinogenesis in female albino rats was investigated in this work. Ethanolic extract of SP fruits was supplemented to the experimental groups at a concentration of 500 mg/kg body weight for 22 weeks. Administration of SP extract suppressed DMBA-induced mammary carcinogenesis as revealed by incidence of tumors in histological investigation. There was a significant reduction in cell proliferation and an increase in apoptosis with downregulation of estrogen receptor expression in the mammary tissue of SP-treated animals. Additionally, SP extract prevented the oxidative damage induced in breast tissues of DMBA-treated rats. SP treatment also decreased the viability of MCF-7 breast cancer cells and induced early and late apoptosis and induced S cell cycle arrest. The chemo-preventive properties and anticancer effects of SP could be attributed to its anti-oxidative and a high percentage of phenolic compounds and esters which were detected here in the SP fruit extract.

Mangiferin Inhibits Inflammation and Cell Proliferation, and Activates Proapoptotic Events via NF-κB Inhibition in DMBA-Induced Mammary Carcinogenesis in Rats.

The purpose of this study was to investigate the anti-inflammatory, antiproliferatiive, and proapoptotic molecular mechanisms of mangiferin (MGN) against mammary carcinogenesis induced by 7,12-dimethylbenz(a)anthracene (DMBA). Mammary cancer in rats was induced by single-dose subcutaneous injection of 0.5 ml DMBA (80 mg/kg in sesame oil) in the mammary gland. Increased tumor incidence and volume and other tumorigenic properties were observed. Further, we observed in these rats reduced antioxidant enzyme activity and elevated thiobarbituric acid reactive substance (TBARS) levels in plasma and tissues. DMBA-induced rats shows enhanced expression of the inflammatory markers NF-κBp65, COX-2, and iNOS and proliferation of PCNA and Cyclin D1, and overexpression of the antiapoptotic marker Bcl-2. Mangiferin (100 mg/kg body weight), administered orally once per day, significantly enhanced (p < 0.05) antioxidant levels and reduced TBARS levels. Moreover, MGN inhibited NF-κBp65 nucleus transcriptional activation, thereby suppressing inflammation and cell proliferation, and it increased proapoptotic proteins. Apoptosis was confirmed by TUNEL assay. In summary, MGN suppressed DMBA-induced mammary carcinogenesis through enhanced antioxidant levels, NF-κB inhibition, and positive regulation of apoptotic signals.

A Novel Ruthenium-Fluvastatin Complex Downregulates SNCG Expression to Modulate Breast Carcinoma Cell Proliferation and Apoptosis via Activating the PI3K/Akt/mTOR/VEGF/MMP9 Pathway.

Breast cancer is the most common cause of malignancy and cancer-related morbidity and death worldwide that requests effective and safe chemotherapy. Evaluation of metallodrug-based anticancer agents and statins as chemotherapeutics with fewer side effects is a largely unexplored research field. Synthesis and characterization of the ruthenium-fluvastatin complex were achieved using multiple spectroscopic techniques and thus further examined to evaluate its chemotherapeutic prospects in both MDA-MB-231 and MCF-7 cancer lines and eventually in vivo models of DMBA-induced mammary carcinogenesis in rodents. Our studies indicate that the metal and ligand chelation was materialized by the ligand's functional groups of carbonyl (=O) oxygen and hydroxyl (-OH), and the complex has been observed to be crystalline and able to chelate with CT-DNA. The complex was able to reduce cell proliferation and activate apoptotic events in breast carcinoma cell lines MCF-7 and MDA-MB-231. In addition, the complex was able to modify p53 expressions to interfere with apoptosis in the carcinoma of the breast, stimulated by the intrinsic apoptotic path assisted by Bcl2 and Bax in vivo, yet at the same point, controlling the PI3K/Akt/mTOR/VEGF pathway, as obtained from western blotting, correlates with the MMP9-regulated tumor mechanisms. Our research reveals that ruthenium-fluvastatin chemotherapy may disrupt, rescind, or interrupt breast carcinoma progression by modifying intrinsic apoptosis as well as the antiangiogenic cascade, thereby taking the role of a potential candidate in cancer therapy for the immediate future.

Nobiletin Attenuates Cell Proliferation by Modulating the Activating Protein-1 Signaling Pathway in 7,12-Dimethylbenz[a]anthracene-Induced Mammary Carcinogenesis.

Breast cancer is a widespread disease that affects women globally. Diagnostic processes and remedial approaches to breast carcinogenesis have improved in recent decades, but continuous survival of patients with breast carcinogenesis is still lacking due to increased cell proliferation. The aim of the present work is to explore the anticell proliferative effects of nobiletin (NOB) against 7,12-dimethylbenz[a]anthracene (DMBA)-treated mammary tumorigenesis in rats. We stimulate mammary carcinogenesis using oral gavage of DMBA (25 mg/kg body weight) mixed with olive oil (1 mL). This results in reduced body weight; increased liver marker enzymes such as alkaline phosphatase, acid phosphatase, aspartate aminotransferase, and alanine aminotransferase; and cell proliferative markers such as c-Jun, proliferating cell nuclear antigen, c-Fos, cyclin D1, and activating protein-1 (AP-1) in the DMBA-treated cancer-bearing animals. NOB administration improved body weight, significantly reduced hepatic marker enzymes, and altered histopathological changes. Furthermore, NOB efficiently reduced tumor cell proliferation markers in DMBA-induced mammary carcinogenesis. Overall, these results suggest that NOB has an anticell proliferative effect on DMBA-induced mammary cancer via modulation of the AP-1 signaling pathway.

Synergistic efficacy of RLIP inhibition and 2'-hydroxyflavanone against DMBA-induced mammary carcinogenesis in SENCAR mice.

Substantial evidence suggests that 7,12-dimethylbenzanthracene (DMBA)-induced mammary carcinogenesis in mice mimics human breast cancer (BC) in many respects. Therefore, it has been used extensively to evaluate preventive and therapeutic agents for human BC. Mammary carcinogenesis induced by DMBA administration in female SENsitive to CARcinogen (SENCAR) mice was characterized by histopathological analysis of the mammary glands and alterations to the phosphatidylinositol 3-kinase/protein kinase B/cyclin-dependent kinase 1 (PI3K/Akt/CDK1) pathway. We recently reported that 2'-hydroxyflavanone (2HF) is a promising diet-derived chemotherapeutic agent that suppresses BC growth in vitro and in vivo by targetinga 76 kDa ral-interacting protein (RLIP). The objective of the current study was to investigate the synergistic anticarcinogenic effects of RLIP inhibition/depletion and 2HF in an in vivo model of DMBA-induced mammary carcinogenesis in SENCAR mice. Mice were given 2HF (50 mg/kg, bw, orally on alternate days), RLIP antibody (Rab; 5 mg/kg, bw, ip weekly), RLIP antisense (RAS; 5 mg/kg, b.w., ip weekly), or a combination of 2HF + Rab + RAS. Animals were monitored daily, and 7 days after the first appearance of moribund behavior, tissues were harvested for morphological and immunohistological analysis. Western blot analyses were performed to determine the expression of anti- and proapoptotic proteins in the mammary glands. Our results reveal that 2HF, RAS, and Rab significantly prevented the carcinogenic effects of DMBA administration in the mammary glands and other organs. Further, mice treated with a combination of 2HF + RAS + Rab exhibited no carcinogenic effect of DMBA as compared to either or the single agent-treated mice. This study demonstrates for the first time the anticarcinogenic effects of 2HF and RLIP inhibition/depletion in vivo in a novel DMBA-induced model of BC in SENCAR mice and provides the rationale for further clinical investigation.

Biochemical studies evaluating the chemopreventive potential of brucine in chemically induced mammary carcinogenesis of rats

The present study was aimed to investigate the dose dependent chemopreventive activity of brucine against 7, 12-dimethylbenz (a) anthracene induced mammary gland tumorigenesis in rats. The mammary tumor was induced by a single dose of DMBA (25 mg/rat) injected subcutaneously near the mammary gland. We observed reduced body weight and increase in tumor incidence, the total number of tumors, and tumor volume in DMBA alone injected rats and also observed decreased antioxidant status (SOD, CAT, GPX, and GSH) and increased lipid peroxidation (TBARS and LOOH) in plasma and mammary tissues. Increased levels of CYP450, Cyt-b5 and decreased levels of phase II (GST and GR) biotransformation enzymes were noticed in the liver and mammary tissues. Further, increased levels of lipid profile (TC, TG, PL, and FFA) and lipoprotein (LDL and VLDL) were noticed. Whereas, decrease in the levels of HDL in plasma and decreased levels of PL and FFA in mammary tissues were observed. Oral administration of brucine in different doses (2, 4 and 8 mg/kg bw) inhibited the tumor incidence and restored the levels of biochemical markers near to normal in dose responsive manner. Biochemical findings are supported by histopathological studies. The results suggest that brucine at a dose of 8 mg/kg bw shows more significant chemopreventive activity in DMBA-induced mammary carcinogenesis.

Taxifolin binds with LXR (α & β) to attenuate DMBA-induced mammary carcinogenesis through mTOR/Maf-1/PTEN pathway.

7,12-dimethylbenz(a)anthracene(DMBA), a PAH derivative initializes cascades of signaling events that alters a variety of enzymes responsible for lipid and glucose homeostasis resulting in enhanced availability and consumption of energy producing molecules for the development of carcinogenesis. 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoAR) is a key enzyme regulating the pathway of synthesis of cholesterol whereas liver-X-receptor (LXR) regulates lipid, carbohydrate metabolism in various malignancies including mammary carcinogenesis (MC). In this study Taxifolin (TAX), a potential flavanoid has been subjected to evaluate its anti-cancer potential on (MC). We designed to screen the molecular docking analysis of TAX on LXRα, LXRβ, HMG-CoAR, mTOR and PTEN using MAESTRO tool comparing with their reference ligands. MC was developed by the administration of DMBA in the air pouch (under the mammary fat pad) of the female Sprague-Dawley rats (55 days old). After 90 days of cancer induction, the chemotherapeutic potential of TAX was evaluated by administering TAX at different doses (10, 20 and 40 mg/kg b.w./day). Then western blot and RT-qPCR analysis were performed for determination of the protein and mRNA expressions respectively. The docking analysis revealed significant interaction with LXR (α&β), HMG-CoAR, mTOR and PTEN. The docking results were validated with the enzyme inhibition assay using HMG-CoAR (EC 1.1.1.34). TAX inhibited the HMG-CoAR activity with an IC50 value of 97.54 ± 2.5 nM whereas the reference molecule pavastatin revealed an IC50 value of 84.35 ± 1.2 nM. Moreover, TAX modulated the energy regulation on DMBA-induced MC in SD-rats by significantly restoring the cancer-induced alterations in body weight, tumor growth and lipid, lipoproteins, lipid metabolizing enzymes and glycolytic enzymes. TAX interacted with LXRs, HMG-CoAR, metabolic enzymes and restored the altered metabolism that accelerates uncontrolled cell proliferation in MC. Moreover, TAX also altered the mRNA and protein expressions of HMG-CoAR, LXR (α,β), Maf1, PTEN, phosphoinositide 3-kinase (PI3K), Akt, mTOR, fatty acid synthase (FASN) and acetyl-CoA carboxylase 1 (ACC1) in a dose dependent manner. These results validate the anti-cancer potential of TAX in DMBA-induced MC through LXR-mTOR/Maf1/PTEN axis.

7,8-Dihydroxycoumarin exerts antitumor potential on DMBA-induced mammary carcinogenesis by inhibiting ERα, PR, EGFR, and IGF1R: involvement of MAPK1/2-JNK1/2-Akt pathway.

Breast cancer (BC) is a persistent and impulsive metabolic disorder with the highest prevalence in women, worldwide. 7,12-Dimethylbenz(a)anthracene (DMBA) is a potent polyaromatic hydrocarbon (PAH)-based carcinogen producing mammary carcinomas in rats resembling the human hormone-dependent BC. 7,8-Dihydroxycoumarin (78DC) is a coumarin derivative that possesses diversified and favorable pharmacology profile to be considered in anticancer research against various malignancies. The present study was intended to investigate the antiproliferative and chemotherapeutic potentials of 78DC (20, 40, and 80mg/kg BW) against DMBA (20mg in olive oil)-induced mammary carcinoma Sprague-Dawley rats. We established the in silico approach for evaluation of the effect of 78DC on hormonal (estrogen receptor-α (ERα), progesterone receptor (PR)), growth factor receptors (EGFR and IGFR), 17β-hydroxysteroid dehydrogenase type 1 (17β-HD1), and aromatase. Effect of 78DC on estrogen synthesis, tumor growth, proliferation markers (Ki-67 and PCNA), cytokines (IL-10, IL-1β, IL-12), chemokine (MCP-1), and cellular expressions of ERα, PR, EGFR, IGF1R, p-MAPK1/2, p-JNK1/2, p-Akt, 17β-HD1, and aromatase was evaluated in mammary carcinoma bearing SD rats. DMBA induces large tumor burden and histological alterations in mammary gland with a subsequent increase in ERα, PR, EGFR, IGF1R, Ki-67, proliferating cell nuclear antigen (PCNA), cytokines, and chemokine expressions. This was also correlated with the changes in rapid cell differentiation and proliferation. In contrast, 78DC treatment to the cancer-bearing animals abbreviated these changes and revealed to possess antitumorigenic and antiproliferative potentials. Further, a significant decrease in expressions of ERα, PR, EGFR, IGFR, p-MAPK1/2, p-JNK1/2, p-Akt, 17β-HD1, and aromatase signifies a reduction in estrogen sensitivity and secondary signaling pathways that may contribute to the prevention of tumor growth. The current findings revealed that 78DC potentially reduce cancer cell proliferation and reverted mammary cancer-induced changes in experimental animals in a dose-dependent manner.

Effects of Obesity on Pro-Oxidative Conditions and DNA Damage in Liver of DMBA-Induced Mammary Carcinogenesis Models.

The prevalence of the overweight and obesity is on the rise worldwide. Obesity can increase the risk of certain cancers and liver steatosis development. Previously, we reported that obesity increased liver steatosis in a mammary tumor model, but little is known about the effects of obesity in the liver in regard to global DNA methylation, DNA damage, and oxidative/nitrosative stress. Using a mammary tumor model, we investigated the effects of obesity on oxidative stress and DNA reaction. Five-week-old lean and obese female rats were used. At 50 days of age, all rats received 7,12-dimethylbenz(α)anthracene (DMBA) and were sacrificed 155 days later. HPLC with electrochemical and ultraviolet detection and LC-MS were used. Obesity caused higher (p < 0.0004) methionine levels, had no effect (p < 0.055) on SAM levels, caused lower (p < 0.0005) SAH levels, caused higher (p < 0.0005) SAM/SAH ratios, and increased (p < 0.02) global DNA methylation. Levels of free reduced GSH were not significantly lower (p < 0.08), but free oxidized GSSG was higher (p < 0.002) in obese rats. The GSH/GSSG ratio was lower (p < 0.0001), and oxidized guanosine was higher (p < 0.002) in DNA of obese rats compared to lean rats. Obesity caused significant oxidative/nitrosative stress, oxidative DNA damage, and change of DNA methylation pattern in the liver, and these changes may contribute to the development of liver steatosis in breast cancer models.

Allyl isothiocyanate, a potent chemopreventive agent targets AhR/Nrf2 signaling pathway in chemically induced mammary carcinogenesis.

In the present study, we investigated the effect of allyl isothiocyanate (AITC) on liver detoxification signaling pathway in 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary carcinogenesis. Mammary tumor was induced by a single dose of DMBA (25mg/rat) injected subcutaneously near the mammary gland in Sprague-Dawley rats. DMBA-alone-treated rats show an increased synthesis of phase I detoxification enzymes, lipid peroxidative markers, liver marker enzymes, and lipid profiles whereas, depletion of phase II detoxification enzymes and antioxidants in rat liver tissues. Oral administration of AITC restored the levels of biochemical markers in DMBA-treated rats.Furthermore, histopathological results also confirmed that AITC protects DMBA-mediated hepatocellular damage. We also observed that AITC treatment significantly downregulates AhR and upregulates the expression of Nrf2 in DMBA-treated rats. The binding efficacy of AITC with AhR and Nrf2 analysis by molecular docking studies reveals that AITC has strong interaction with AhR and Nrf2 proteins through hydrogen and hydrophobic interactions. Thus, AITC prevents DMBA-induced mammary carcinogenesis via inhibition of phase I and induction of phase II detoxification enzymes by modulating AhR/Nrf2 signaling pathway.

Protective Effect of Allyl Isothiocyanate on Glycoprotein Components in 7,12-dimethylbenz(a)anthracene Induced Mammary Carcinoma in Rats

The present study aimed to investigate the protective effect of allyl isothiocyanate (AITC) on glycoprotein components in 7,12-dimethylbenz(a)anthracene (DMBA) induced mammary carcinogenesis in female Sprague-Dawley rats. Mammary tumor was induced by a single dose of DMBA (25mg/rat) injected subcutaneously near mammary gland. The levels of glycoprotein components such as hexose, hexosamine and sialic acid were analyzed colorimetrically in plasma, mammary and liver tissues. We observed an increased levels of glycoprotein components in plasma, mammary and liver tissues in cancer bearing rats. It was further confirmed by Periodic Acid Schiff staining in mammary and liver tissues. Upon oral administration of AITC to DMBA injected rats, the abnormal changes were reverted back to near normal levels and biochemical findings are supported by histological analysis. This could be due to the anti-neoplastic potential of AITC against DMBA-induced mammary carcinogenesis. The result shows that AITC has the potential to inhibit abnormal glycosylation that favors neoplastic transformation.

Multi Floral Honey Has a Protective Effect against Mammary Cancer Induced by 7,12-Dimethylbenz(a)anthracene in Sprague Dawley Rats

This research was conducted to study the protective effect of bee honey on the 7,12-dimethylbenz(a)anthracene (DMBA)- induced breast cancer in rat model. The study consisted of three groups: honey group, positive control group (PC), and negative control group (NC) to which the carcinogen was not administered. All rats were fed the diet recommended by the American Institute of Nutrition for growing rats (AIN-93G), with addition of honey (50 g/kg diet) to the honey group. All Rats were fed their diets ad libitum on 12 hours dark/light cycle. At the age of 50 days all rats in the honey and PC groups were gavaged once by the carcinogen DMBA with a dose of 80 mg/kg body Wt. After three weeks of carcinogen administration, rats were palpated weekly to detect any tumor growth. After 18 weeks, all rats were sacrificed. The palpable structures and the mammary glands along with associated lymph nodes were removed and fixed in saline formalin and prepared for histopathological examination. The results revealed that the honey group diet significantly (p &lt; 0.05) reduced the incidence rate of mammary cancer, palpable tumor multiplicity, tumor size and weight compared to the PC group. In conclusion, multi floral honey has a protective effect against DMBA- induced mammary cancer in the initiation, promotion, and progression stages of DMBA-induced mammary carcinogenesis. However, further research is needed to reveal the mechanisms that might have contributed to the preventive effect of honey against mammary cancer.

Taxifolin Inhibits 7,12-Dimethylbenz(a)anthracene-induced Breast Carcinogenesis by Regulating AhR/CYP1A1 Signaling Pathway.

Background:Breast cancer (BC), because of its invasive characteristics, is one of the most common and deadliest cancers among the female population around the world. Research has demonstrated that AhR signaling also plays a vital role in BC initiation and development as well. Therefore, blocking this pathway to natural interferences paves a new channel for the prevention of BC. Several natural compounds such as flavonoids possess the anticancer activities against different cancers.Objective:The present study has been designed to estimate the chemotherapeutic potential of taxifolin (TAX) against 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary carcinoma in Sprague-Dawley rats.Materials and Methods:Initially, the molecular docking analysis of AhR and cytochrome P450s (CYPs) (CYP1A1 and CYP1B1) was performed using MAESTRO tool, in an attempt to rationalize the activity of TAX, based on their CYP1-binding potential. The in vitro CYP1A1 activity was determined by luciferase assay with CYP1A1 substrate luciferin CEE. The in vivo analysis was performed by administrating TAX at 10, 20, 40 mg/kg BW for 28 days intragastrically in DMBA induced (25 mg/animal dose) at 55 days of age Sprague-Dawley (SD) rats. BC initiates after 90 days of tumor induction phase. The molecular mechanism of TAX on Ahr and CYPs was also examined through the mRNA and protein expressions using reverse transcription-quantitative polymerase chain reaction and Western blotting analysis.Results:Furthermore, TAX altered the energy regulation on DMBA-induced BC in SD rats by considerably restoring the cancer-induced modulations in tumor growth. Our results showed that TAX reduced the expressions of CYP1A1 and CYP1B1 in DMBA-induced mammary carcinoma by downregulating the AhR signaling pathway.Conclusion:This study revealed that TAX might be able to act as a chemotherapeutic agent against CYP1A1- and CYP1B1-mediated cancer and the inhibition of the DMBA-induced mammary carcinogenesis in a rat model.Abbreviations used: CYPs: Cytochrome P450s; PAH: polycyclic aromatic hydrocarbons; HRP- Horseradish peroxidase; BSA: Bovine serum albumin; DTTP: Deoxythymidine Triphosphate (nucleotide); RT-qPCR: Real Time quantitative polymerase chain reaction; CADD: Computer Aided Drug Drafting.

Efficacy of Pleurotus ostreatus (Jacq. Ex Fr.) P.kumm. on 7,12-dimethylbenz(a)anthracene induced mammary carcinogenesis in female Sprague-Dawley rats

Neoplastic growth of the breast is the most common malignancy in women worldwide and its incidence has increased in most countries. In this study, we have evaluated the efficacy of Pleurotus ostreatus (Jacq. Ex Fr.) P.kumm. (P. ostreatus) an edible mushroom on modulating levels of xenobiotic metabolizing enzymes, hormonal status of estrogen and progesterone receptor (ER/PR), protein expressions and histopathological analysis in 7,12-dimethylbenz(a)anthracene (DMBA) induced mammary carcinogenesis using a rat model. DMBA was induced by single subcutaneous injection at a dosage of 25mg in 1mL vehicle. The ethanolic extract of P. ostreatus (POEet) was administered orally at a concentration of 600mg/kg bwt as pre- and post-initiation stage of treatment throughout the experimental period which was also compared with standard tamoxifen (TAM) (10mg/kg bwt). At the end of 16 weeks, our results showed the elevated phase I and depleted phase II metabolizing enzymes, over expression of (ER/PR) and the expression pattern of the proteins such as fas, fasL, caspase 3, caspase 8, caspase 9, Bax were found to be down regulated whereas p53, Bcl2, cox-2 and cyclin D1 were markedly upregulated in DMBA-induced Sprague-Dawley rats, which were significantly reversed on P. ostreatus administration. Moreover, pre-treatment with P. ostreatus showed improved response when compared to that of posttreatment. Based on scientific appraisal, we conclude that the dietary consumption of P. ostreatus might offer maximum protection against DMBA-induced mammary carcinogenesis and improving human health if used as a regular basis. Focal points•Benchside○ The potential of Pleurotus ostreatus on DMBA induced rat mammary carcinogenesis were determined by the analysis of xenobiotic metabolizing enzymes, hormonal status of ER/PR, as well as the expression of protein using western blotting techniques and histological examination of liver and mammary tissues.•Bedside○ The pharmaceutical potential of P. ostreatus are analysed for is markedly available, edible one with high protein as well as fiber with low fat content and cost effective for patient convenience.•Industry○ Mushrooms are considered as a nutraceutical functional food which can contain enriched prolific produced of novel “mycochemicals” responsible for the human health potential on various diseases and malignancies.•Community○ Standardization and refinement of mycochemical from mushrooms were help to develop the new novel active compounds which contribute for better health and also help to reduce disease burden.•Regulatory agencies○ The P. ostreatus contain several bioactive compounds which might be the key factor for the anticancer effect. This will need to be taken for labeling and pattering the compounds and tested in clinical trials.

Collected literature on isoflavones and chronic diseases

AbstractIsoflavones are organic compounds, which have been linked to the health benefits and prevention of many diseases. Common isoflavones are genistein, daidzein, and glycitein. Genistein has been researched in regard to its effect on the reduction of menopausal symptoms and reduction of cardiovascular risk factors in osteopenic, post-menopausal women. Research on daidzein focuses on bone mineral density implications in post-menopausal women, therapeutic effects early in prostate cancer, and protection against DMBA-induced mammary carcinogenesis. The most recent research on daidzein has implications for its effect on cardiovascular risk reduction. Research on glycitein focuses on it bioavailability, as well as its role in angiogenesis and invasion of malignant glioma cells. The health benefits of these specific isoflavones are instrumental in the prevention and treatment of many diseases. This review of literature focuses on the effects of genistein, daidzein, and glycitein on health outcomes, such as ...

Modulatory effect of Pleurotus ostreatus on oxidant/antioxidant status in 7, 12-dimethylbenz (a) anthracene induced mammary carcinoma in experimental rats--A dose-response study.

Worldwide, breast cancer is the second most prevalent cancer among women and its incidence is increasing alarmingly. To determine a dose-response effect of Pleurotus ostreatus on oxidant/antioxidant status in 7,12-dimethylbenz. (a) antheracene induced. (DMBA) mammary carcinoma in experimental rats. Cancer bearing female Sprague Dawley rats were orally treated with Pleurotus ostreatus ethanolic extract (POEet) (150, 300 and 600 mg/kg body weight) for 16 weeks. By means of high performance liquid chromatography (HPLC) analysis, ergosterol (48.82%) were identified and quantified in POEet. Body weight of experimental rats in each groups and the biochemical parameters of plasma, liver and mammary tissues were carried out. Histopathological analyses were also determined. Results were analyzed using SPSS software package, version 16.0. The values were analyzed by one way analysis of variance (ANOVA) followed by Duncan's multiple range test (DMRT). The result showed that depleted activities of enzymatic and non-enzymatic antioxidant level and significant elevated TBARS level were observed in DMBA group of plasma, mammary and liver tissues of experimental rats. The effects were dose.dependent and the above noted parameters were renovated to near normal after supplementation with different dose of POEet (150 mg, 300 mg and 600 mg/kg bwt). The data obtained from the study indicate that POEet at a dose of 600 mg/kg bwt possesses optimum anticancer effects against DMBA induced mammary carcinogenesis. Based on the scientific appraisal, we conclude that the POEet is having a potent antioxidant capacity; thereby it offers maximum protection against DMBA-induced mammary carcinogenesis.

Abstract 2720: Toll-like receptor 4 immunoreactivity in mammary tumors chemically induced in female Sprague-Dawley rats

Abstract Toll-like receptors (TLRs) are essential type I transmembrane glycoproteins that play a major role in inflammation and innate immune system. TLRs have been investigated in cancer research due to their dual role in tumor progression. The TLRs signaling pathways can promote survival, cell proliferation and apoptosis and its stimulation may either enhance or inhibit tumor growth and metastasis. The role of TLR4 in cancer biology has been studied but the direct relation between TLR4 and development of many cancer types, including breast cancer, is still obscure. Thus, more studies about TLR4 expression in breast cancer can help to better understanding the involvement of TLR4 in this disease. The aim of this study was to investigate the expression of TLR4 in a rat mammary carcinogenesis model. At 51 days of age, female Sprague-Dawley rats were allocated into three groups: Groups 1 and 2 (n = 12 each) were initiated for mammary carcinogenesis by a single i.g. dose of 7,12-dimethylbenz[a]anthracene (DMBA) (80mg/kg) and Group 3 (n = 6) received a single i.g. dose of sesame oil (DMBA vehicle, 1 ml/kg). Also, group 2 received five s.c. injections per week of Tamoxifen (100 μg/kg) and groups 1 and 2 received similar injections of sesame oil (Tamoxifen vehicle, 0.5 ml/kg) during 12 weeks. At week 13, the animals were euthanized and mammary tumor (groups 1 and 2) and non-altered mammary glands (group 3) were collected and processed for histophatological analysis and TLR4 expression by immunohistochemistry. The TLR4 expression was classified as weak, moderate or strong and the incidence of intensity scores in tumor samples/group was analyzed by Fisher's exact test. Significant differences when p&amp;lt;0.05. Most of mammary tumors were classified as adenocarcinomas with tubular, papillary, cribriform or mixed patterns. Also, the tumors presented an expansive growth pattern with local invasive areas but without metastasis. Besides, a tumor inflammatory response was more intensively observed in G2. The immunoreactivity for TLR4 was significantly stronger in non-altered alveolar and ductal epithelial cells (G1) than in mammary tumor epithelial cells (groups 1 and 2) (p&amp;lt; 0.001 and p = 0.007, respectively). The TLR4 immunoreactivity was more intense in mammary tumor epithelial cells from tamoxifen-treated group than in positive control group (G1), but without a significant difference. In the tumor stroma the positivity for TLR4 was observed mainly in mononuclear inflammatory cells, showing a strong positivity for this marker in groups G1 and G2 when compared to the stromal cells from non-altered mammary tissue (G1, p = 0.028, p&amp;lt; 0,001). This present study show that there is a significant reduction in TLR4 expression in tumor epithelial cells when compared to the normal compartment in this rat DMBA-induced mammary carcinogenesis model. Besides, the intensity of the inflammatory response in the tumor microenvironment can alter the immunoreactivity for TLR4. Citation Format: Joyce Regina Zapaterini, Muriele Bertagna Varuzza, Nelci Antunes Moura, Maria Aparecida Marchesan Rodrigues, Luis Fernando Barbisan. Toll-like receptor 4 immunoreactivity in mammary tumors chemically induced in female Sprague-Dawley rats. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2720. doi:10.1158/1538-7445.AM2015-2720

The effect of zinc and phytoestrogen supplementation on the changes in mineral content of the femur of rats with chemically induced mammary carcinogenesis

The aim of this study was to assess skeletal effects of zinc or zinc with phytoestrogen (resveratrol or genistein) supplementation in an animal model of rats with DMBA-induced mammary carcinogenesis. The changes in bone parameters such as the length and mass were examined, as well as the changes in concentrations of selected minerals: calcium, magnesium, zinc, iron and phosphorus. Moreover, the investigations focused on finding the differences between the levels of iron and zinc in other tissues: the liver, spleen and serum of the examined rats.Fifty-six female Sprague–Dawley rats, 40 days old, were divided into four groups, regardless of the diets: standard (77mg Zn kg/food), zinc (4.6mg/mL via gavage), zinc (4.6mg/mL) plus resveratrol (0.2mg/kgbw), and zinc (4.6mg/mL) plus genistein (0.2mg/kgbw) for a period from 40 days until 20 weeks of age. The study rats were also treated with 7,12-dimethyl-1,2-benz[a]anthracene (DMBA) to induce mammary carcinogenesis.The applied diet and the advanced mammary cancer did not affect macrometric parameters of the rats’ bones, but they strongly affected their mineral content. It was found that mammary cancer, irrespectively of the applied diet, significantly modified the iron level in the femur, liver, spleen and serum of the examined rats. In addition, zinc supplementation significantly lowered the levels of calcium, magnesium and phosphorus in the femur of rats with mammary cancer as compared with respective levels in the control group. So, it was found that additional supplementation with zinc, which is generally considered to be an antioxidant, with the co-existing mammary carcinoma, increased the unfavorable changes as concerns the stability of bone tissue. The appropriate combination of zinc and phytoestrogens (resveratrol or genistein) could help prevent or slow bone loss associated with a range of skeletal disorders in breast cancer.