Carcinogenesis In Rats Research Articles

Antitumor and Antibacterial Efficacy of Gallium Nanoparticles Coated by Ellagic Acid.

Cancer is a mortality contributor worldwide, and breast cancer is the most common among women. Despite the numerous breast cancer therapeutic strategies, they either have limitations or sometimes are resisted by cancer, so new approaches are needed to tackle those restrictions. Nanotechnology offers exciting leaps in the diagnosis and treatment of cancer, especially breast cancer. The main objective of this study was to investigate the effect of the newly synthesized gallium nanoparticles coated by Ellagic acid (EA-GaNPs) on the induced mammary gland carcinogenesis in female rats and their antibacterial activities comparison with standard antibiotics (Ketoconazole (100 μg/ml) and Gentamycin (4 μg/ml)) by disc diffusion method using eight different microbial species. The antitumor efficacy of EA-GaNPs was conducted both in vitro and in in vivo. The result of antimicrobial activity of EA-Ga NPs (1 mg/1 mL) revealed moderate toxicity behavior against Gram-positive {Staphylococcus aureus, Bacillus subtilis, Bacillus cereus) and Gram-negative pathogenic bacteria {Escherichia coli, Proteus vulgarfs) also, antifungal activity was detected against {Aspergillus terreus). In vitro study showed that EA-GaNPs inhibited human breast cancer cell line (MCF-7) proliferation with IC50 of 2.86 μg/ml. Although in vivo; the administration of EA-GaNPs to DMBA-treated rats ameliorated the hyperplastic state of mammary gland carcinogenesis induced by DMBA. Additionally, EA-GaNPs administration significantly modulated the activities of ALT and AST, as well as the levels of urea and creatinine in serum. Also, EA-GaNPs administration improved the antioxidant state by increasing Superoxide dismutase activity and GSH content, and decreasing malondialdehyde content in the mammary tissue, besides enhancing the apoptotic activity through elevating the levels of caspase-3 and decreasing the protein intensities of protein kinase B & phosphatidyl inositide 3-kinases. Furthermore, a significant decrease in serum Total iron-binding capacity accompanied by a significant increase in the level of calcium was noted. So, it can be concluded that the newly synthesized nanoparticles EA-GaNPs have an efficient antitumor activity that was manifested by reduction of the viability on the human breast cancer cell line (MCF-7) in vitro. Also, in vivo against the chemically induced mammary gland carcinogenesis in a female rat model. Histopathological findings were in harmony with biochemical and molecular results showing the effectiveness of EA-GaNPs against mammary carcinogenesis. Therefore, EA-GaNPs could be a promising, potent anti-cancer compound.

Effect of Eremomastax polysperma on some Tumour Markers of 7,12-Dimethylbenz(A) Anthracene Induced Mammary Carcinogenesis in Female Rats

Effect of Eremomastax polysperma on some Tumour Markers of 7,12-Dimethylbenz(A) Anthracene Induced Mammary Carcinogenesis in Female Rats

The state of pro- and antioxidant systems in rats with DMH-induced colon carcinogenesis on the background of extracorporeal detoxification

Aim: Cancer is one of the leading causes of death in the world. The aim of this research was to study the indices of pro- and antioxidant systems in rats with dimethylhydrazine (DMH)-induced colon carcinogenesis on the background of the enterosorbent AUT-M use. Materials and methods: The study was performed on 70 white male rats weighing 200–250 g. Adenocarcinoma of the colon was simulated by subcutaneous injection of the DMH (Sigma-Aldrich Chemie, Japan) at a dose of 7.2 mg/kg once a week during 7 months. Enterosorbent AUT-M was administered intragastrically daily for 21 days after simulation of carcinogenesis at a dose of 1 ml of suspension per 100 g of animal body weight. The state of the pro- and antioxidant systems was studied by the content of oxidative modification of proteins products (OMP), the activity of superoxide dismutase (SOD), catalase (CAT), contents of ceruloplasmin (CP) and reduced glutathione (GSH). Results: It was found that DMH-induced colon carcinogenesis in rats is accompanied by disorders in the antioxidant defense system and activation of free radical oxidation processes. Enterosorbent AUT-M provides a significant reduction in the content of OMP370 and OMP430 in both blood serum and liver homogenate of rats. Moreover, the use of enterosorbent AUT-M demonstrated a significant increase in the activity of SOD, CAT, content of GSH and a decrease in CP content in investigated tissues. Conclusion: The use of enterosorbent AUT-М demonstrated prominent potential suppression for oxidative stress and positive effect on antioxidant defense system in rats with DMH-induced colon carcinogenesis.

Nigella Sativa’s Protection Against 7,12 Dimethylbenz [A] Anthracene -Induced Colon Carcinogenesis in Rats

Colon cancer is the third most common cause of death from cancer worldwide. Recently, natural products have been widely used as an alternative therapy for colon cancer. Previous studies have reported that Nigella sativa has chemopreventive activity in vitro and in vivo.This study aimed to evaluate the effect of Nigella sativa seed (NSS) on rat-colon cell after initiation of 7,12-dimethylbenz [a] anthracene. Rats were divided into five groups, 12 rats in each group: Group I was given 7,12dimetilbenz [a] anthracene (DMBA) orally 20 mg/kgBW twice a week for five weeks, group V is the solvent control group was given corn oil. The other three groups were given DMBA + NSS, at the dosage of 250 mg/kgBW, 500 mg/kgBW and 750 mg/kgBW. NSS extract was dissolved in corn oil and administered daily per oral during the next two weeks before and during the initiation of DMBA. After 16 weeks, all rats were sacrificed. H&E staining showed that necrosis activity was lower in treated groups compared to DMBA group. AgNOR staining showed mAgNOR was significantly decrease following the increasing dose of NSS (250 mg/kgBW, 500 mg/kgBW and 750 mg/kgBW) were subsequently 1.62 ± 0.086, 1.60 ± 0.101 and 1.39 ± 0.049 (p<0.05). The results showed that NNS reduce the damage of colon cells and inhibit colon cell proliferation in DMBA induced rats.

THERAPEUTIC PROFILING OF NANO ENCAPSULATED DIOSGENIN VIA ATTENUATING HORMONAL STATUS, CELL PROLIFERATION, INFLAMMATORY RESPONSES, AND APOPTOSIS IN AN ANIMAL MODEL OF MAMMARY ONCOGENESIS

Objective: The central motive of this study is to explore the therapeutic impact of Diosgenin encapsulated Chitosan nanoparticles (DG@CS-NP) on mammary carcinogenesis in female Sprague Dawley rats via modulating hormonal status, cell proliferation, inflammatory responses, and Apoptosis. Methods: 7,12-dimethylbenz(a)anthracene (DMBA) was administered subcutaneously near the mammary gland (25 mg/kg b. wt) to provoke mammary tumor in female Sprague Dawley rats. Following the progress of a tumor, DMBA-induced tumor-bearing rats were medicated orally with 5 mg/kg b. wt of DG@CS-NP. Consequently, the expression of ER, PR, PCNA, Cyclin D1, NF-κB, TNF-α, Bcl-2, Caspases-3, and p53 in experimental rats were revealed via architectural immunohistochemistry. Further, Diosgenin interactions with these proteins were evidently confirmed by molecular docking analysis. Results: As a result, we noticed diminished levels of ER, PR, PCNA, Cyclin D1, NF-κB, TNF-α, and Bcl-2 expressions in DG@CS-NP medicated rats as well as with elevated levels of Caspases-3 and p53 expressions. In DMBA rats, the expressions were vice versa. Additionally, molecular docking analyses support these outcomes by highlighting the strong interaction between Diosgenin and breast cancer targets. Conclusion: These reports prove that DG@CS-NP imposes its therapeutic impact by hormonal adjustments, downregulating proteins involved in inflammation and cellular proliferation, and thereby promotes apoptosis by impeding apoptotic inhibitors.

Cold exposure and capsaicin promote 1,2-dimethylhyrazine-induced colon carcinogenesis in rats correlates with extracellular matrix remodeling.

BACKGROUNDExtracellular matrix (ECM) remodeling and stiffening, which are correlated with tumor malignancy, drives tumor development. However, the relationship between ECM remodeling and rat experimental model of 1,2-dimethylhyrazine (DMH)-induced colorectal cancer (CRC) imposed by cold and capsaicin exposure remains unclear.AIMTo explore the effects of cold exposure and capsaicin on ECM remodeling and ECM enzymes in DMH-induced CRC.METHODSFor histopathological analysis, the sections of colon tissues were stained with hematoxylin and eosin, Masson’s trichrome, Picrosirius red, and Weigert’s Resorcin-Fuchsin to observe the remodeling of collagen and elastin. Additionally, the protein expression level of type I collagen (COL I), type 3 collagen (COL III0, elastin, matrix metalloproteinase (MMP) 1, MMP2, MMP9, and tissue-specific matrix metalloproteinase 1 (TIMP1) was assessed by immunohistochemistry. The messenger RNA (mRNA) levels of COL I, COL III, elastin, and lysyl oxidase-like-2 (LOXL2) in the colon tissues of rats was measured by reverse-transcriptase quantitative polymerase chain reaction.RESULTSAlthough no differences were observed in the proportion of adenomas, a trend towards the increase of invasive tumors was observed in the cold and capsaicin group. The cold exposure group had a metastasis rate compared with the other groups. Additionally, abnormal accumulation of both collagen and elastin was observed in the cold exposure and capsaicin group. Specifically, collagen quantitative analysis showed increased length, width, angle, and straightness compared with the DMH group. Collagen deposition and straightness were significantly increased in the cold exposure group compared with the capsaicin group. Cold exposure and capsaicin significantly increased the protein levels of COL I, elastin, and LOXL2 along with increases in their mRNA levels in the colon tissues compared with the DMH group, while COL III did not show a significant difference. Furthermore, in immunohistochemical evaluations, MMP1, MMP2, MMP9, and TIMP1 staining increased in the cold exposure and capsaicin group compared with the DMH group.CONCLUSIONThese results suggest that chronic cold and capsaicin exposure further increased the deposition of collagen and elastin in the colonic tissue. Increased COL I and elastin mRNA and protein levels expression may account for the enhanced ECM remodel and stiffness variations of colon tissue. The upregulated expression of the LOXL2 and physiological imbalance between MMP/TIMP activation and deactivation could contribute to the progression of the CRC resulting from cold and capsaicin exposure.

Age-dependent effects on radiation-induced carcinogenesis in the rat thyroid

Childhood radiation exposure is a known thyroid cancer risk factor. This study evaluated the effects of age on radiation-induced thyroid carcinogenesis in rats irradiated with 8 Gy X-rays. We analyzed cell proliferation, cell death, DNA damage response, and autophagy-related markers in 4-week-old (4W) and 7-month-old (7M) rats and the incidence of thyroid tumors in 4W, 4-month-old (4M), and 7M rats 18 months after irradiation. Cell death and DNA damage response were increased in 4W rats compared to those in controls at 1 month post-irradiation. More Ki-67-positive cells were observed in 4W rats at 12 months post-irradiation. Thyroid tumors were confirmed in 61.9% (13/21), 63.6% (7/11), and 33.3% (2/6) of irradiated 4W, 4M, and 7M rats, respectively, compared to 0%, 14.3% (1/7), and 16.7% (1/6) in the respective nonirradiated controls. There were 29, 9, and 2 tumors in irradiated 4W, 4M, and 7M rats, respectively. The expression of several autophagy components was downregulated in the area surrounding radiation-induced thyroid carcinomas in 4W and 7M rats. LC3 and p62 expression levels decreased in radiation-induced follicular carcinoma in 4W rats. Radiosensitive cells causing thyroid tumors may be more prevalent in young rats, and abrogation of autophagy may be associated with radiation-induced thyroid carcinogenesis.

Research Profile: Dr. Jeevan K. Prasain

Dr. Jeevan K. Prasain is an associate professor of pharmacology and toxicology at the University of Alabama at Birmingham. His current research focuses on delineation of unconventional cyclooxygenase (Cox)-independent prostaglandin (PG) synthesis mechanism, mass spectrometry-based metabolomics/lipidomics, biological activity, and uptake and metabolisms of dietary botanicals in vitro and in vivo. Dr. Prasain received his MSc in chemistry from Tribhuvan University located in Kathmandu, Nepal and went on to obtain his PhD in Japan from the Toyama Medical and Pharmaceutical University in pharmaceutical sciences. During his PhD tenure, he devoted much of his studies to natural product chemistry resulting in the discovery of several novel bioactive diarylheptanoids, subjects he went on to publish in several papers. After the completion of his PhD, he was awarded the Canadian Government Visiting Fellowship at the Biotechnology Research Institute (BRI) in Montreal, Canada to pursue postdoctoral research. During his time at BRI, Dr. Prasain was involved in drug discovery and high throughput screening of bioactive natural products from natural product libraries and their analysis by tandem mass spectrometry. Through this research, Dr. Prasain later went on to be a recipient of a Science and Technology Award at RIKEN in Tokyo Japan where he developed a mass spectrometry method for analysis of antibiotic cytochalasins. Based on his experiences in natural products research, he developed a great interest in dietary polyphenols in the promotion of health and prevention of chronic disease. Dr. Prasain joined the University of Alabama at Birmingham (UAB) as a postdoctoral fellow with Dr. Stephen Barnes in 2001, where he was later promoted to Assistant Professor in 2003. One of his research focuses was on the understanding of antidiabetic effects of puerarin, an isoflavone C-glucoside from Kudzu root and its metabolism and bioavailability. Kudzu root is well-known in traditional Chinese medicine, and various kudzu root based dietary supplements are available in the US market. Prasain's lab, in collaboration with Dr. Elias Meezan, also at UAB, demonstrated that puerarin treatment significantly improves glucose tolerance in C57 BL/6J ob/ob mice, an animal model of Type 2 diabetes mellitus. Specifically, puerarin blunts the rise in blood glucose levels after i.p. administration of glucose. Prasain et al. also found that in contrast to its O-glucoside isomer daidzin, puerarin is essentially absorbed without undergoing metabolism and is excreted in the urine mainly as an unchanged parent. In addition, in collaboration with Dr. Clinton Grubbs at UAB on the role of cranberry juice in bladder cancer prevention in animals, Prasain et al. demonstrated that commercially available cranberry juice concentrate can prevent urinary bladder cancers dose-dependently in N-butyl-N-(4-hydroxybutyl)-nitrosamine (OH-BBN) induced bladder carcinogenesis in rats when compared to the control group. This study also indicated that cranberry compounds once ingested reach the urinary bladder and concentrate in the urine in either the intact or in the metabolized forms and may prevent against the progression of carcinogenesis. This is because bladder cancers occur almost exclusively in the bladder epithelium, which is directly exposed to the urine stored in the bladder. In 2009, Dr. Prasain received an NIH R21 funding for investigating urinary metabolites of cranberry that protect against bladder cancer. The primary focus of this project was to understand what cranberry metabolites stored in the bladder are bioavailable and which metabolites are responsible against bladder carcinogenesis. The other focus of Dr. Prasain's lab is in the area of lipidomics, particularly profiling and characterizing PGs and other signaling lipids using tandem mass spectrometry. Using a combination of genetics, microinjection, and mass spectrometry, the late Dr. Michael Miller's and Dr. Prasain's labs discovered that C. elegans oocytes secrete sperm attractants F-series PGs derived from polyunsaturated fatty acid precursors. This NIH funded research led to an unanticipated discovery that C. elegans and mice generate specific F-series PGs without Cox enzymes. Over the past several years, much of the Dr. Prasain's lab effort has been to identify genes essential for Cox-independent PG synthesis and the signaling mechanisms that regulate PG functions in reproductive biology. The authors declare no conflict of interest.

Pharmacological and Toxicological evaluation of selenium in combination with thiamine in chemically induced hepatocarcinogenesis

Hepatocellular carcinoma (HCC) is currently holding the second rank as a fatal cancer globally. Our hypothesis projects the combined effect of selenium (3mg/kg) and thiamine in combination as an effective treatment for DENA induced carcinogenesis in Wistar rats with an intra-peritoneal single dose of 200mg/kg body weight. Data obtained proved to show a remarkable alteration in body weight and liver profile of DENA exposed rats which were restored by administration of selenium and thiamine combination; our histological reports also revealed reparative changes in the trabaculie mesh work of hepatic cells at higher doses than the normal dietary requirement. Outcomes of the protocol showed remarkable fruitful results for the justification of combined selenium and thiamine as anticancer therapy.

Capsaicin Encapsulated Chitosan Nanoparticles Augments Anticarcinogenic and Antiproliferative Competency Against 7,12 Dimethylbenz(a)anthracene Induced Experimental Rat Mammary Carcinogenesis

Background: Capsaicin is a powerful phytochemical spotted in chilies, starkly tied up with a bunch of health benefits but its clinical applications in cancer therapy are limited due to its poor solubility, and low bioavailability. Nanotechnology offers a strategy to discover new formulations for hydrophobic agent.
 Aim: The main intent of the current research was to investigate the effect of Capsaicin encapsulated chitosan nanoparticles (CAP@CS-NP) on 7,12-Dimethylbenz(a)anthracene (DMBA) induced mammary carcinogenesis in rats.
 Methodology: Mammary tumor was induced in female rats by injecting DMBA (25mg/kg b.wt) at the first week of the experiment. After 7 weeks, CAP@CS-NP (4mg/kg b.wt) was administered orally to DMBA induced tumor bearing rats for 21 days (thrice per week). The experiment was terminated at the end of the 14th week and their plasma and tissue sections were analyzed.
 Results: We found that significantly elevated levels of lipid peroxidation and diminished levels of antioxidant status in plasma, liver and mammary tissues. Increased levels of detoxification phase I enzymes and dropped levels of phase II enzymes in liver and mammary tissues in DMBA induced tumor bearing rats. As a result, oral administration of CAP@CS-NP suppressed the tumor growth, significantly raised body weight and restored abnormal enzymatic levels to near normal ranges. Additionally, histopathological and immunohistochemical analysis were also confirmed that CAP@CS-NP protects DMBA mediated cellular disruption and also inhibits abnormal cell proliferation.
 Conclusion: These findings suggest that nano encapsulation of CAP@CS-NP could be useful in targeted drug delivery and act as a promising chemotherapeutic agent to treat mammary carcinogenesis.

Amelioration of oxidative stress, inflammation and tumor promotion by Tin oxide-Sodium alginate-Polyethylene glycol-Allyl isothiocyanate nanocomposites on the 1,2-Dimethylhydrazine induced colon carcinogenesis in rats

Colorectal cancer (CRC) is a frequently diagnosed cancer that primarily affects the digestive system and an imperative cause of mortalities worldwide. In this work, we formulated the Tin oxide-Sodium alginate-Polyethylene glycol-Allyl isothiocyanate nanocomposites (SAP-Ally-NCs) and investigated its anticancer role against the DMH-provoked CRC in rats. The formulated SAP-Ally-NCs were characterized different techniques. The CRC was provoked to the rats via injecting 20 mg/kg of DMH and then administered with the formulated SAP-Ally-NCs for 16 weeks. The bodyweight changes and the polyp’s incidences were detected and tabulated. The status of lipid peroxidation and antioxidant enzymes were studied by standard techniques. The inflammatory markers and xenobiotic enzymes level was scrutinized using respective kits. The mRNA expressions of various signaling molecules were examined by RT-PCR. The liver and colon tissues were examined microscopically to detect the histological changes. The formulated SAP-Ally-NCs treatment appreciably improved the body weight gain and suppressed the polyp’s incidences in the DMH-challenged animals. SAP-Ally-NCs treated animals were demonstrated the notable reduction in the lipid peroxidation and inflammatory cytokines and elevated the antioxidant enzymes i.e. CAT and SOD activity. SAP-Ally-NCs administered animals exhibited the noticeable reduction in the expression of PCNA, cyclin-D1, iNOS, and COX-2 in the colon tissues. The histological findings also unveiled the therapeutic role of SAP-Ally-NCs. In conclusion, the SAP-Ally-NCs demonstrated the potent anticancer action against the DMH-provoked CRC in rats. In future, it could be a potent chemotherapeutic agent to the CRC.

Chemopreventive Effect of Stoechospermum marginatum against Experimental Colon Carcinogenesis Induced by 1, 2-Dimethyl Hydrazine

Background: Colon cancer is the one most prevalent malignancy in the world and its incidence is increasing due to changing life styles, environmental factors, etc. Conventional chemotherapy for cancer is limited due to development of chemoresistance and severe side effects. Natural products have received great attention in the recent years owing to its reduced toxicity and side effects. The present was undertaken to evaluate chemopreventive potential of ethanolic extract of Stoechospermum marginatum in experimentally induced colon carcinogenesis in rats. Methods: Healthy male wistar rats were divided into 6 groups and received following treatments: Vehicle (Group I); S. marginatum extract (Group II), DMH alone (Group III), DMH + 5-Fluorouracil (Group IV), DMH +S. marginatum extract at 100 mg/kg (Group V) and DMH +S. marginatum extract at 200 mg/kg (Group VI). Colon tumour was induced using 1, 2-dimethylhydrazine (DMH). Result: S. marginatum extract ameliorated oxidative damaging effects of DMH. S. marginatum extract increased expression of Bax, caspase 3 and caspase 9; decreased expression of Bcl-2 and restored levels of COX-2 compared to tumor control. Reduced aberrant crypt foci, hyperplastic and inflammatory changes in colon were observed with S. marginatum compared to tumour control. The findings suggest chemopreventive potential of S. marginatum.

The immunomodulatory effects of topiramate on azoxymethane-induced colon carcinogenesis in rats: The role of the inflammatory cascade, vascular endothelial growth factor, AKT/mTOR/MAP kinase signaling and the apoptotic markers

BackgroundColon cancer is a malignant condition that affects the lower gastrointestinal tract and has unfavorable prognosis. Its mechanisms range from enhanced production of reactive oxygen species, inflammatory changes in the colon microenvironment and affection of the apoptotic pathways. Due to the high incidence of resistance of colon cancer to the traditional chemotherapeutic agents, a need for finding safe/effective agents that can attenuate the malignant changes had emerged. ObjectiveTo investigate the possible immunomodulatory and antitumor effects of topiramate on azoxymethane-induced colon cancer in rats. MethodologyFifty male Wistar rats were randomized into five equal groups as follows: Control; azoxymethane-induced colon cancer; azoxymethane + methyl cellulose; azoxymethane + topiramate small dose; and azoxymethane + topiramate large dose. The body weight gain, serum carcinoembryonic antigen (CEA), tissue antioxidant status, proinflammatory cytokines, vascular endothelial growth factor (VEGF), Nrf2/HO-1 content, p-AKT, mTOR, p38 MAP kinase, caspase 9, nerve growth factor beta and beclin-1 were measured. Also, parts of the colon had undergone histopathological and immunohistochemical evaluation. Key findingsTopiramate improved the body weight gain, decreased serum CEA, augmented the antioxidant defenses in the colonic tissues with significant amelioration of the inflammatory changes, decline in tissue VEGF and p-AKT/mTOR/MAP kinase signaling and increased Nrf2/HO-1 content in a dose-dependent manner when compared to rats treated with azoxymethane alone. In addition, topiramate, in a dose-dependent manner, significantly enhanced apoptosis and improved the histopathological picture in comparison to animals treated with azoxymethane alone. ConclusionTaking these findings together, topiramate might serve as a new effective adjuvant line of treatment of colon cancer.

Effect of Kefir, Yacon (Smallanthus sonchifolius) and the Association Between Yacon and Kefir on Intestinal Physiology in Rats With Colon Cancer

Abstract Objectives To evaluate the effect of consumption of yacon flour, kefir and the association between them on colon cancer induced by 1,2-dimethylhydrazine (DMH) in male Wistar rats, SCFA production, fecal pH and intestinal permeability. Methods The study was conducted with 60 adult Wistar rats divided into 5 groups. For 5 weeks, groups T, Y, K and YK received 1,2-dimethylhydrazine (DMH) to induce colon cancer. After 5 weeks of DMH administration, animals in groups C and T received the standard diet, group Y received a diet with yacon flour with 5% FOS, group K received 1mL /day of kefir and the YK group received a diet with yacon and kefir, for 15 weeks. After euthanasia, intestinal lesions, intraluminal pH, short-chain fatty acids (SCFA) and intestinal permeability were analyzed. Results An increase in macroscopic lesions was observed in groups K (58%) and YK (42%) and a reduction of 5% in group Y, compared to group T. In addition, an increase in neoplastic changes was observed in all groups compared to group T: Y (33%), K (67%) and YK (78%). There was no significant difference in the concentrations of acetate and proprionate, pH, lactulose and mannitol between groups, and butyrate was not found in the samples. Conclusions The consumption of yacon flour, kefir and their association did not influence intestinal physiology and promoted the worsening of the development of colon carcinogenesis in rats. Funding Sources FAPES - Fundação de Amparo à Pesquisa e Inovação do Espírito Santo CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico

Ellagitannins from jabuticaba (Myrciaria jaboticaba) seeds attenuated inflammation, oxidative stress, aberrant crypt foci, and modulated gut microbiota in rats with 1,2 dimethyl hydrazine-induced colon carcinogenesis

Since dietary factors are thought to be responsible for high colon cancer risk, we investigated the chemopreventive effect of jabuticaba seed extract (LJE) by administering yogurt with or without LJE against 1,2 dimethyl hydrazine (DMH)-induced colon carcinogenesis in rats. Results showed that LJE contained a total phenolic content of 57.16 g/100 g of seed extract in which 7.67 and 10.09 g/100 g represented total flavonoids and ellagitannins, respectively. LJE protected DNA and human LDL against induced in vitro oxidation, which was associated with the ellagitannin content and with the free-radical scavenging and reducing capacities. LJE alone had a non-clastogenicity/aneugenicity property, but in combination with cisplatin, it enhanced the chromosome aberrations in cancer cells. In colon cancer-induced rats, yogurt with or without LJE caused a reduction in pro-inflammatory parameters, decreased the RNA expression of antiapoptotic cytokines and increased the expression of proapoptotic cytokines. Moreover, LJE attenuated colon cancer initiation and progression by decreasing aberrant crypt foci and LJE recovered the gut microbiome. Together, this evidence suggests that LJE provides chemopreventive protection against colon cancer development by reducing inflammation and increasing proapoptotic pathways.

Local Immune Changes in Early Stages of Inflammation and Carcinogenesis Correlate with the Collagen Scaffold Changes of the Colon Mucosa.

Simple SummaryChronic colitis and colon cancer develop for alteration of the mucosa homeostatic regulation, also involving TGF-β1. Dextran sulphate sodium (DSS)-induced colitis and azoxymethane (AOM)-induced colorectal carcinogenesis animal models allow for the investigation of the pathological evolution steps. Since chronic inflammation is a common factor, we aimed to explore in rat models the colon mucosa immunological and structural conditions at one month after the end of the inductions, a transition period between acute effects and established lesions. We found, in comparison to healthy controls, downregulation of inflammatory cytokines (except IL-6) and of TGF-β1. At the same time, the collagen scaffold was significantly remodelled in both groups. We conclude that the pro-inflammatory cytokines, in front of a downregulated TGF-β1, sustained a smouldering inflammation with structural changes preparing the niche of both pathologies (ulcerative colitis with fibrosis; tumour). The collagen scaffold changes pointing to an unnoticed inflammation may be suggested as a possible pre-neoplastic condition marker.Continuous activation of the immune system inside a tissue can lead to remodelling of the tissue structure and creation of a specific microenvironment, such as during the tumour development. Chronic inflammation is a central player in stimulating changes that alter the tissue stroma and can lead to fibrotic evolution. In the colon mucosa, regulatory mechanisms, including TGF-β1, avoid damaging inflammation in front of the continuous challenge by the intestinal microbiome. Inducing either DSS colitis or AOM colorectal carcinogenesis in AVN-Wistar rats, we evaluated at one month after the end of each treatment whether immunological changes and remodelling of the collagen scaffold were already in development. At this time point, we found in both models a general downregulation of pro-inflammatory cytokines and even of TGF-β1, but not of IL-6. Moreover, we demonstrated by multi-photon microscopy the simultaneously presence of pro-fibrotic remodelling of the collagen scaffold, with measurable changes in comparison to the control mucosa. The scaffold was significantly modified depending on the type of induced stimulation. These results suggest that at one month after the end of the DSS or AOM inductions, a smouldering inflammation is present in both induced conditions, since the pro-inflammatory cytokines still exceed, in proportion, the local homeostatic regulation of which TGF-β1 is a part (inflammatory threshold). Such an inflammation appears sufficient to sustain remodelling of the collagen scaffold that may be taken as a possible pathological marker for revealing pre-neoplastic inflammation.

Protective Role of Vanillic Acid against Diethylnitrosamine- and 1,2-Dimethylhydrazine-Induced Hepatocarcinogenesis in Rats.

This study aimed to evaluate the cancer chemopreventive activity of vanillic acid (VA) in diethylnitrosamine- and 1,2-dimethylhydrazine-induced liver and colon carcinogenesis in rats. VA did not induce the formation of hepatic glutathione S-transferase placental form (GST-P) positive foci and colonic aberrant crypt foci, demonstrating no carcinogenic activity. VA (75 mg kg−1 body weight) could significantly reduce the number and areas of hepatic GST-P positive foci when administered before carcinogen injections, but no such effect was seen when it was administered after carcinogen injection. No protection was seen in the colon when VA was treated before or after carcinogen injection. Immunohistochemical studies demonstrated the decreased expression of proliferating cell nuclear antigen and the induction of apoptosis. Mechanistic studies showed that VA significantly induced the expression of GSTA-5 and Nrf-2 genes, which are associated with the detoxification system. Likewise, the antiproliferative effect was noticed by the reduction of Cyclin D1 expression. The apoptotic activity may be due to the upregulation of Caspase-3 and Bad levels and downregulation of the Bcl-2 level. These data suggest that VA exhibited significant protection against diethylnitrosamine- and 1,2-dimethylhydrazine-induced hepatocarcinogenesis, which might be related to the induction of the detoxifying enzyme, the reduction of proliferation and the induction of apoptosis.

Protective Effects of Antioxidant Chlorophyllin in Chemically Induced Breast Cancer Model In vivo.

Glutathione-related enzymes belong to the protection mechanism of the cells against harmful oxidative damage and chemicals. Glutathione S-transferase (GST) is frequently over-expressed in various cancer cells and is involved in drug resistance. Chlorophyllin is an antioxidant molecule interfering with the GST P1-1 activity. The purpose of this study is to evaluate the short- and long-term protective effects of chlorophyllin as an antioxidant molecule on DNA damage, antioxidant enzyme activities, trace elements, and minerals in chemically induced breast cancer model in vivo. In our study, N-methyl-N-nitrosourea (MNU) was used for inducing breast carcinogenesis in female Sprague-Dawley rats. A total of 36 rats were divided into groups as short term and long term. Each group was divided into four sub-groups as control group received physiological saline solution (n= 3), Chl group (n= 5) received chlorophyllin, MNU group (n= 5) was administered MNU, and Chl + MNU group (n= 5) was treated with both chlorophyllin and MNU. Results illustrated that chlorophyllin had a significant anti-genotoxic effect in the short term, and glutathione-related enzyme activities were protected by chlorophyllin treatment in MNU-induced breast cancer model. Additionally, MNU administration impaired mineral and trace element levels including Na, Mg, K, Fe, Zn, and Co in the liver, kidney, spleen, heart, and tumor tissues; however, adverse effects of MNU were recovered upon chlorophyllin treatment in the indicated tissues of the rats. In conclusion, chlorophyllin can be used as an antioxidant molecule to ameliorate adverse effects of MNU by enhancing antioxidant enzyme activities and regulating trace element and mineral balance in several organs and tumor tissue in the breast cancer model.

Phyllanthin prevents diethylnitrosamine (DEN) induced liver carcinogenesis in rats and induces apoptotic cell death in HepG2 cells

Liver cancer is a critical clinical condition with augmented malignancy, rapid progression, and poor prognosis. Liver cancer often initiates as fibrosis, develops as cirrhosis, and results in cancer. For centuries, medicinal plants have been incorporated in various liver-associated complications, and recently, research has recognized that many bioactive compounds from medicinal plants may interact with targets related to liver disorders. Phyllanthin from the Phyllanthus species is one such compound extensively used by folklore practitioners for various health benefits. However, most practices continue to be unrecognized scientifically. Hence, in this work, we investigated the protective role of phyllanthin on diethylnitrosamine (DEN) induced liver carcinoma in Wistar Albino rats and the anti-tumor potential on human hepatocellular carcinoma (HCC) HepG2 cells. The DEN-challenged liver cancer in experimental rats caused increased liver weight, 8-OHD, hepatic tissue injury marker, lipid peroxidation, and tumor markers levels. Remarkably, phyllanthin counteracted the DEN effect by ameliorating all the liver function enzymes, oxidative DNA damage, and tumor-specific markers by enhanced anti-oxidant capacity and induced caspase-dependent apoptosis through the mTOR/ PI3K signaling pathway. MTT assay demonstrated that phyllanthin inhibited the HepG2 cell growth in a dose-dependent manner. Fascinatingly, phyllanthin did not demonstrate any substantial effect on the normal cell line, HL7702. In addition, HepG2 cells were found in the late apoptotic stage upon treatment with phyllanthin as depicted by acridine orange/ethidium bromide staining. Overall, this work offers scientific justification that phyllanthin can be claimed to be a safe candidate with potential chemotherapeutic activity against HCC.

The Protective Role of Urtica dioica Seed Extract Against Azoxymethane-Induced Colon Carcinogenesis in Rats

The aim of this study was to investigate the protective role of Urtica dioica seed (UDS) extract against azoxymethane (AOM)-induced colon carcinogenesis in rats. Thirty-two male Wistar albino rats were divided into four groups: Control, AOM, AOM + UDS, and UDS. The AOM and AOM + UDS groups were induced by AOM (15 mg/kg body weight) subcutaneously once a week for 10 weeks. AOM + UDS and UDS groups additionally received fed with pellets included 30 ml/kg UDS extract. At the end of the trial, blood and colon tissue samples were taken from the rats following necropsy. The gross and histopathological findings revealed that the administration of UDS extract significantly decreased lesions including aberrant cript foci, adenoma, and adenocarcinoma formation both numerically and dimensionally. Immunohistochemically, slight CEA and COX-2, strong Caspase-3 immune-expressions were detected in the group AOM + UDS compared to AOM group. Biochemical examinations indicated that a markedly increase in the malondialdehyde and fluctuated antioxidant defense system constituents levels such as reduced glutathione, glutathione s-transferase, glutathione peroxidase, superoxide dismutase were restored in AOM + UDS group. These results reveal that the UDS may act as a chemopreventive dietary agent, inducing apoptosis, resulting in a significant reduction of colon carcinogenesis.