RÉSUMÉ
Introduction: Based on extensive data from oncology research, the use of phytochemicals or plant-based nutraceuticals is considered an innovative tool for cancer management. This research aimed to analyze the oncostatic properties of Salvia officinalis L. [Lamiaceae; Salviae officinalis herba] using animal and in vitro models of breast carcinoma (BC). Methods: The effects of dietary administered S. officinalis in two concentrations (0.1%/SAL 0.1/and 1%/SAL 1/) were assessed in both syngeneic 4T1 mouse and chemically induced rat models of BC. The histopathological and molecular evaluations of rodent carcinoma specimens were performed after the autopsy. Besides, numerous in vitro analyses using two human cancer cell lines were performed. Results and Conclusion: The dominant metabolites found in S. officinalis propylene glycol extract (SPGE) were representatives of phenolics, specifically rosmarinic, protocatechuic, and salicylic acids. Furthermore, the occurrence of triterpenoids ursolic and oleanolic acid was proved in SPGE. In a mouse model, a non-significant tumor volume decrease after S. officinalis treatment was associated with a significant reduction in the mitotic activity index of 4T1 tumors by 37.5% (SAL 0.1) and 31.5% (SAL 1) vs. controls (set as a blank group with not applied salvia in the diet). In addition, salvia at higher doses significantly decreased necrosis/whole tumor area ratio by 46% when compared to control tumor samples. In a rat chemoprevention study, S. officinalis at a higher dose significantly lengthened the latency of tumors by 8.5 days and significantly improved the high/low-grade carcinomas ratio vs. controls in both doses. Analyses of the mechanisms of anticancer activities of S. officinalis included well-validated prognostic, predictive, and diagnostic biomarkers that are applied in both oncology practice and preclinical investigation. Our assessment in vivo revealed numerous significant changes after a comparison of treated vs. untreated cancer cells. In this regard, we found an overexpression in caspase-3, an increased Bax/Bcl-2 ratio, and a decrease in MDA, ALDH1, and EpCam expression. In addition, salvia reduced TGF-ß serum levels in rats (decrease in IL-6 and TNF-α levels were with borderline significance). Evaluation of epigenetic modifications in rat cancer specimens in vivo revealed a decline in the lysine methylations of H3K4m3 and an increase in lysine acetylation in H4K16ac levels in treated groups. Salvia decreased the relative levels of oncogenic miR21 and tumor-suppressive miR145 (miR210, miR22, miR34a, and miR155 were not significantly altered). The methylation of ATM and PTEN promoters was decreased after S. officinalis treatment (PITX2, RASSF1, and TIMP3 promoters were not altered). Analyzing plasma metabolomics profile in tumor-bearing rats, we found reduced levels of ketoacids derived from BCAAs after salvia treatment. In vitro analyses revealed significant anti-cancer effects of SPGE extract in MCF-7 and MDA-MB-231 cell lines (cytotoxicity, caspase-3/-7, Bcl-2, Annexin V/PI, cell cycle, BrdU, and mitochondrial membrane potential). Our study demonstrates the significant chemopreventive and treatment effects of salvia haulm using animal or in vitro BC models.
RÉSUMÉ
The purpose of this study was to assess the potential effects of Rhus coriaria L. (sumac) and of Cinnamomum zeylanicum L. bark on the selected serum cytokines as possible serum tumor markers - interleukin-6 (IL-6), interleukin-10 (IL-10), and tumor necrosis factor-α (TNF-α) in the rat model of mammary carcinogenesis. R. coriaria and C. zeylanicum bark were used as the chemopreventive-therapeutic agents taken by rats in the powder form in the diet at two different concentrations during the entire period of two experiments carried out separately: lower concentration 1 g/kg - 0.1% and higher concentration 10 g/kg - 1%. The serum levels of cytokines of IL-6, IL-10, and TNF-α were determined using an enzyme-linked immunosorbent assay. In the first experiment treated with R. coriaria, a significant decrease in serum levels of IL-6 and TNF-α was present at higher concentrations compared to the chemoprevention-free control group. R. coriaria at lower concentrations non-significantly reduced the serum levels of IL-6 and TNF-α when compared to controls. A significant decrease in serum levels of TNF-α was present at higher concentrations compared to lower concentrations. The significant effect of R. coriaria on the serum levels of IL-10 was not observed. In the second experiment treated with C. zeylanicum bark, a significant decrease in serum levels of IL-6 was observed in lower and higher concentrations compared to the chemoprevention-free control group. C. zeylanicum bark non-significantly reduced the serum levels of TNF-α and had no effect on the serum levels of IL-10. In conclusion, R. coriaria and C. zeylanicum bark demonstrated significant anti-inflammatory effects by analyzing the selected serum cytokine levels in the rat breast carcinoma model. Observed anti-inflammatory effects of both plant-natural substances were associated with their anticancer activities in rats.
Sujet(s)
Cytokines , Rhus , Rats , Animaux , Interleukine-10 , Cinnamomum zeylanicum , Interleukine-6 , Facteur de nécrose tumorale alpha , Écorce , Extraits de plantes/pharmacologie , Anti-inflammatoires/pharmacologie , CarcinogenèseRÉSUMÉ
BACKGROUND: Clostridioides (Clostridium) difficile is the most common nosocomial pathogen and antibiotic-related diarrhea in health-care facilities. Over the last few years, there was an increase in the incidence rate of C. difficile infection cases in Slovakia. In this study, the phenotypic (toxigenicity, antimicrobial susceptibility) and genotypic (PCR ribotypes, genes for binary toxins) patterns of C. difficile isolates from patients with CDI were analyzed, from July to August 2016, taken from hospitals in the Horne Povazie region of northern Slovakia. The aim of the study was also to identify hypervirulent strains (e.g., the presence of RT027 or RT176). METHODS: The retrospective analysis of biological samples suspected of CDI were analyzed by GDH, anaerobic culture, enzyme immunoassay on toxins A/B, multiplex "real-time" PCR and PCR capillary-based electrophoresis ribotyping, and by MALDI TOF MS. RESULTS: C. difficile isolates (n = 44) were identified by PCR ribotyping, which revealed five different ribotypes (RT001, 011, 017, 081, 176). The presence of hypervirulent RT027 was not identified. The C. difficile isolates (RT001, 011, 081, 176) were susceptible to metronidazole and vancomycin. One isolate RT017 had reduced susceptibility to vancomycin. A statistically significant difference between the most prevalent PCR ribotypes, RT001 and RT176, regarding variables such as albumin, CRP, creatinine, the length of hospitalization (p = 0.175), and glomerular filtration (p = 0.05) was not found. CONCLUSION: The results of PCR capillary-based electrophoresis ribotyping in the studied samples showed a high prevalence of RT176 and 001.
RÉSUMÉ
The global pandemic of coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is having a tremendous impact on the global economy, health care systems and the lives of almost all people in the world. The Central European country of Slovakia reached one of the highest daily mortality rates per 100,000 inhabitants in the first 3 months of 2021, despite implementing strong prophylactic measures, lockdowns and repeated nationwide antigen testing. The present study reports a comparison of the performance of the Standard Q COVID-19 antigen test (SD Biosensor) with three commercial RT-qPCR kits (vDetect COVID-19-MultiplexDX, gb SARS-CoV-2 Multiplex-GENERI BIOTECH Ltd. and Genvinset COVID-19 [E]-BDR Diagnostics) in the detection of infected individuals among employees of the Martin University Hospital in Slovakia. Health care providers, such as doctors and nurses, are classified as "critical infrastructure", and there is no doubt about the huge impact that incorrect results could have on patients. Out of 1231 samples, 14 were evaluated as positive for SARS-CoV-2 antigen presence, and all of them were confirmed by RT-qPCR kit 1 and kit 2. As another 26 samples had a signal in the E gene, these 40 samples were re-isolated and subsequently re-analysed using the three kits, which detected the virus in 22, 23 and 12 cases, respectively. The results point to a divergence not only between antigen and RT-qPCR tests, but also within the "gold standard" RT-qPCR testing. Performance analysis of the diagnostic antigen test showed the positive predictive value (PPV) to be 100% and negative predictive value (NPV) to be 98.10%, indicating that 1.90% of individuals with a negative result were, in fact, positive. If these data are extrapolated to the national level, where the mean daily number of antigen tests was 250,000 in April 2021, it points to over 4700 people per day being misinterpreted and posing a risk of virus shedding. While mean Ct values of the samples that were both antigen and RT-qPCR positive were about 20 (kit 1: 20.47 and 20.16 for Sarbeco E and RdRP, kit 2: 19.37 and 19.99 for Sarbeco E and RdRP and kit 3: 17.47 for ORF1b/RdRP), mean Ct values of the samples that were antigen-negative but RT-qPCR-positive were about 30 (kit 1: 30.67 and 30.00 for Sarbeco E and RdRP, kit 2: 29.86 and 31.01 for Sarbeco E and RdRP and kit 3: 27.47 for ORF1b/RdRP). It confirms the advantage of antigen test in detecting the most infectious individuals with a higher viral load. However, the reporting of Ct values is still a matter of ongoing debates and should not be conducted without normalisation to standardised controls of known concentration.
Sujet(s)
COVID-19 , SARS-CoV-2 , Contrôle des maladies transmissibles , Europe , Hôpitaux , Humains , Sensibilité et spécificité , Slovaquie/épidémiologieRÉSUMÉ
Comprehensive scientific data provide evidence that isolated phytochemicals or whole plant foods may beneficially modify carcinogenesis. The aim of this study was to evaluate the oncostatic activities of Rhus coriaria L. (sumac) using animal models (rat and mouse), and cell lines of breast carcinoma. R. coriaria (as a powder) was administered through the diet at two concentrations (low dose: 0.1% (w/w) and high dose: 1 % (w/w)) for the duration of the experiment in a syngeneic 4T1 mouse and chemically-induced rat mammary carcinoma models. After autopsy, histopathological and molecular analyses of tumor samples in rodents were performed. Moreover, in vitro analyses using MCF-7 and MDA-MB-231 cells were conducted. The dominant metabolites present in tested R. coriaria methanolic extract were glycosides of gallic acid (possible gallotannins). In the mouse model, R. coriaria at a higher dose (1%) significantly decreased tumor volume by 27% when compared to controls. In addition, treated tumors showed significant dose-dependent decrease in mitotic activity index by 36.5% and 51% in comparison with the control group. In the chemoprevention study using rats, R. coriaria at a higher dose significantly reduced the tumor incidence by 20% and in lower dose non-significantly reduced tumor frequency by 29% when compared to controls. Evaluations of the mechanism of oncostatic action using valid clinical markers demonstrated several positive alterations in rat tumor cells after the treatment with R. coriaria. In this regard, histopathological analysis of treated tumor specimens showed robust dose-dependent decrease in the ratio of high-/low-grade carcinomas by 66% and 73% compared to controls. In treated rat carcinomas, we found significant caspase-3, Bax, and Bax/Bcl-2 expression increases; on the other side, a significant down-regulation of Bcl-2, Ki67, CD24, ALDH1, and EpCam expressions and MDA levels. When compared to control specimens, evaluation of epigenetic alterations in rat tumor cells in vivo showed significant dose-dependent decrease in lysine methylation status of H3K4m3 and H3K9m3 and dose-dependent increase in lysine acetylation in H4K16ac levels (H4K20m3 was not changed) in treated groups. However, only in lower dose of sumac were significant decreases in the expression of oncogenic miR210 and increase of tumor-suppressive miR145 (miR21, miR22, and miR155 were not changed) observed. Finally, only in lower sumac dose, significant decreases in methylation status of three out of five gene promoters-ATM, PTEN, and TIMP3 (PITX2 and RASSF1 promoters were not changed). In vitro evaluations using methanolic extract of R. coriaria showed significant anticancer efficacy in MCF-7 and MDA-MB-231 cells (using Resazurin, cell cycle, annexin V/PI, caspase-3/7, Bcl-2, PARP, and mitochondrial membrane potential analyses). In conclusion, sumac demonstrated significant oncostatic activities in rodent models of breast carcinoma that were validated by mechanistic studies in vivo and in vitro.
Sujet(s)
Antinéoplasiques d'origine végétale/pharmacologie , Marqueurs biologiques tumoraux/métabolisme , Tumeurs du sein/traitement médicamenteux , Régulation de l'expression des gènes tumoraux/effets des médicaments et des substances chimiques , Extraits de plantes/pharmacologie , Rhus/composition chimique , Animaux , Apoptose , Marqueurs biologiques tumoraux/génétique , Tumeurs du sein/métabolisme , Tumeurs du sein/anatomopathologie , Cycle cellulaire , Prolifération cellulaire , Femelle , Humains , Souris , Souris de lignée BALB C , Souris nude , microARN/génétique , Rat Sprague-Dawley , Cellules cancéreuses en culture , Tests d'activité antitumorale sur modèle de xénogreffeRÉSUMÉ
Comprehensive oncology research suggests an important role of phytochemicals or whole plant foods in the modulation of signaling pathways associated with anticancer action. The goal of this study is to assess the anticancer activities of Cinnamomum zeylanicum L. using rat, mouse, and cell line breast carcinoma models. C. zeylanicum (as bark powder) was administered in the diet at two concentrations of 0.1% (w/w) and 1% (w/w) during the whole experiment in chemically induced rat mammary carcinomas and a syngeneic 4T1 mouse model. After autopsy, histopathological and molecular evaluations of mammary gland tumors in rodents were carried out. Moreover, in vitro analyses using MCF-7 and MDA-MB-231 cells were performed. The dominant metabolites present in the tested C. zeylanicum essential oil (with relative content over 1%) were cinnamaldehyde, cinnamaldehyde dimethyl acetal, cinnamyl acetate, eugenol, linalool, eucalyptol, limonene, o-cymol, and α-terpineol. The natural mixture of mentioned molecules demonstrated significant anticancer effects in our study. In the mouse model, C. zeylanicum at a higher dose (1%) significantly decreased tumor volume by 44% when compared to controls. In addition, treated tumors showed a significant dose-dependent decrease in mitotic activity index by 29% (0.1%) and 45.5% (1%) in comparison with the control group. In rats, C. zeylanicum in both doses significantly reduced the tumor incidence by 15.5% and non-significantly suppressed tumor frequency by more than 30% when compared to controls. An evaluation of the mechanism of anticancer action using valid oncological markers showed several positive changes after treatment with C. zeylanicum. Histopathological analysis of treated rat tumor specimens showed a significant decrease in the ratio of high-/low-grade carcinomas compared to controls. In treated rat carcinomas, we found caspase-3 and Bax expression increase. On the other hand, we observed a decrease in Bcl-2, Ki67, VEGF, and CD24 expressions and MDA levels. Assessment of epigenetic changes in rat tumor cells in vivo showed a significant decrease in lysine methylation status of H3K4m3 and H3K9m3 in the high-dose treated group, a dose-dependent increase in H4K16ac levels (H4K20m3 was not changed), down-regulations of miR21 and miR155 in low-dose cinnamon groups (miR22 and miR34a were not modulated), and significant reduction of the methylation status of two out of five gene promoters-ATM and TIMP3 (PITX2, RASSF1, PTEN promoters were not changed). In vitro study confirmed results of animal studies, in that the essential oil of C. zeylanicum displayed significant anticancer efficacy in MCF-7 and MDA-MB-231 cells (using MTS, BrdU, cell cycle, annexin V/PI, caspase-3/7, Bcl-2, PARP, and mitochondrial membrane potential analyses). As a conclusion, C. zeylanicum L. showed chemopreventive and therapeutic activities in animal breast carcinoma models that were also significantly confirmed by mechanistic evaluations in vitro and in vivo.
Sujet(s)
Antinéoplasiques d'origine végétale/administration et posologie , Tumeurs du sein/traitement médicamenteux , Cinnamomum zeylanicum/composition chimique , Huile essentielle/administration et posologie , Écorce/composition chimique , Animaux , Antinéoplasiques d'origine végétale/composition chimique , Antinéoplasiques d'origine végétale/pharmacologie , Tumeurs du sein/génétique , Tumeurs du sein/métabolisme , Lignée cellulaire tumorale , Prolifération cellulaire/effets des médicaments et des substances chimiques , Survie cellulaire/effets des médicaments et des substances chimiques , Relation dose-effet des médicaments , Femelle , Histone/métabolisme , Humains , Cellules MCF-7 , Souris , microARN/génétique , Huile essentielle/composition chimique , Huile essentielle/pharmacologie , Huiles végétales/administration et posologie , Huiles végétales/composition chimique , Huiles végétales/pharmacologie , Rats , Tests d'activité antitumorale sur modèle de xénogreffeRÉSUMÉ
AIM: This experimental in vitro study examined differences in the expression and activity of calcium release-activated calcium (CRAC) channels of human term-pregnant and non-pregnant myometrium. MATERIAL AND METHODS: The tissue samples were obtained from term-pregnant myometrium in labor of women undergoing cesarean section and from non-pregnant myometrium of women undergoing total hysterectomy due to uterine myoma. The expression of Orai1 protein, a pore-forming subunit of CRAC channels, in human myometrium was examined using immunohistochemistry. CRAC channel involvement in the amplitude and frequency of myometrial contractions was evaluated in vitro using a tissue bath method with a CRAC ion channel blocker 3-fluropyridine-4-carboxylic acid (FPCA). RESULTS: Decreased Orai1 expression was observed in human term-pregnant laboring myometrium compared with non-pregnant myometrium. However, the initial oxytocin-induced contraction of myometrium was significantly suppressed at different doses of FPCA in both non-pregnant human isolated myometrium and non-pregnant myometrium. The frequency of contractions was the most significantly reduced at the lowest dose of FPCA in non-pregnant myometrium and remained suppressed at all doses of FPCA in term-pregnant myometrium. Salbutamol was shown as more effective in suppression of amplitude in term-pregnant isolated myometrium. CONCLUSION: Our results provide the first information about the changes in the Orai1 protein expression and activity of human myometrial CRAC channels in term-pregnant laboring myometrium.
Sujet(s)
Myomètre/métabolisme , Protéine ORAI1/métabolisme , Contraction utérine/métabolisme , Salbutamol/pharmacologie , Inhibiteurs des canaux calciques/pharmacologie , Femelle , Humains , Acides isonicotiniques/pharmacologie , Myomètre/effets des médicaments et des substances chimiques , Protéine ORAI1/génétique , Grossesse , Contraction utérine/effets des médicaments et des substances chimiques , Contraction utérine/génétiqueRÉSUMÉ
Previous studies in the field of cancer research have suggested a possible role for statins in the reduction of risk in certain malignancies. The purpose of these studies was to examine the chemopreventive effects of pravastatin alone and in combination with pineal hormone melatonin in the N-methyl-N-nitrosourea-induced mammary carcinogenesis model. Pravastatin was given orally (1 00 mg/kg) and melatonin was added to the water (20 µg/ml). Chemoprevention began seven days prior to carcinogen administration and subsequently continued for 15 weeks until autopsy. At autopsy, mammary tumours were removed and prepared for histopathological and immunohistochemical analysis. Parameters of experimental carcinogenesis, mechanism of action (biomarkers of apoptosis, angiogenesis and proliferation) and side effects after long-term treatment in animals were assessed. Pravastatin alone suppressed tumour frequency by 20.5% and average tumour volume by 15% compared with controls. Combined administration of the drugs decreased tumour frequency by 69% and lengthened tumour latency by nine days compared with control animals. The ration between high and low grade carcinomas was apparently reduced in both treated groups. The analysis of carcinoma cells showed significant expression increase in caspase-3 and caspase-7 after pravastatin treatment; however, combined treatment even more pronounced increase in the expression of both caspases. Regarding VEGFR-2 expression, a small effect in carcinomas of both treated groups was found. In plasma metabolism evaluation, pravastatin alone significantly decreased levels of glucose and triacylglycerols. Our results suggest a mild anti-neoplastic effect of pravastatin in this rat mammary gland carcinoma model. Statins co-administered with other suitable drug (e.g. melatonin) should be further evaluated for tumour-preventive properties.
Sujet(s)
Antinéoplasiques/pharmacologie , Carcinome canalaire du sein/traitement médicamenteux , Tumeurs expérimentales de la mamelle/traitement médicamenteux , Mélatonine/pharmacologie , Pravastatine/pharmacologie , Agents alcoylants/pharmacologie , Animaux , Antioxydants/pharmacologie , Apoptose/effets des médicaments et des substances chimiques , Épithélioma in situ/induit chimiquement , Épithélioma in situ/traitement médicamenteux , Épithélioma in situ/anatomopathologie , Carcinome canalaire du sein/induit chimiquement , Carcinome canalaire du sein/anatomopathologie , Carcinome papillaire/induit chimiquement , Carcinome papillaire/traitement médicamenteux , Carcinome papillaire/anatomopathologie , Modèles animaux de maladie humaine , Synergie des médicaments , Femelle , Inhibiteurs de l'hydroxyméthylglutaryl-CoA réductase/pharmacologie , Tumeurs expérimentales de la mamelle/induit chimiquement , Tumeurs expérimentales de la mamelle/anatomopathologie , 1-Méthyl-1-nitroso-urée/pharmacologie , Rat Sprague-DawleyRÉSUMÉ
In the last decades plant substances have become a leading form of treatment of many respiratory symptoms, including cough. It has been shown that compounds purified form polysaccharides from Adhatoda vasica, Withania somnifera, and Glycyrrhiza glabra have various biological activities, such as antioxidant, anti-inflammatory, immunomodulating, antispasmodic action, or antiallergic properties, and they often act as cough suppressants. This work demonstrates new natural substitutes for synthetic antitussives whose application is associated with numerous adverse effects. We investigated pharmacodynamic characteristics of arabinogalacatan samples extracted from A. vasica, W. somnifera, and G. glabra. These extracts showed the ability to reduce citric acid-induced cough in awake guinea pigs after oral administration in a dose of 50mg/kg. The strongest antitussive effect (81%) was found after application of the extract from G. glabra. There was a 67% cough suppression with A. vasica and 61% with W. somnifera, which was comparable with the antitussive activity of codeine (62%).
Sujet(s)
Antitussifs/pharmacologie , Toux/traitement médicamenteux , Phytothérapie/méthodes , Préparations à base de plantes/pharmacologie , Polyosides/pharmacologie , Animaux , Cochons d'Inde , Humains , Mâle , Extraits de plantes/pharmacologieRÉSUMÉ
Allergic asthma is the most frequent disease of the respiratory tract. The aim of the current experimental and clinical studies was to find new sources of drugs able to control asthmatic inflammation and airway hyperresponsiveness. Our experimental studies were focused on efficiency evaluation of substances able to influence activities of ion channels, phosphodiesterase (PDE) isoforms, substances from the group of polyphenols and NO metabolism modulators during experimentally induced allergic asthma.
RÉSUMÉ
AIM: The aim of this study was to assess the participation of ligand-sensitive potassium large conductance calcium-activated ion channels (BK(Ca2+) ) and adenosine triphosphate (ATP)-sensitive potassium ion channels (K(ATP) ) using its openers (NS1619 and pinacidil) in the contractility of human term pregnant myometrium in in vitro conditions. METHODS: Human myometrium tissue samples were collected from term pregnant laboring women who had to undergo cesarean section. The contractility of myometrium was induced by the application of oxytocin into the organ bath. Myometrial strips were incubated with the opener of BK(Ca2+) potassium ion channels NS1619 and its antagonist tetraethylammonium or with the opener of K(ATP) potassium ion channels pinacidil and its antagonist glibenclamide. RESULTS: K(ATP) potassium ion channel's opener pinacidil significantly decreased amplitude of myometrial contractions (P < 0.05) as well as frequency of myometrial contractions (P < 0.05) provoked by oxytocin in human term pregnant myometrium in in vitro conditions. The inhibition of the human myometrial contractions of pinacidil was significantly antagonized by its specific antagonist glibenclamide (P < 0.05). BK(Ca2+) potassium ion channel's opener NS1619 did not significantly affect the contractile activity of human term pregnant myometrium induced by the application of oxytocin in in vitro conditions. CONCLUSION: In our experimental study we found that the participation of BK(Ca2+) and K(ATP) potassium ion channels in the contractility of human term pregnant myometrium in labor is probably different.
Sujet(s)
Canaux KATP/physiologie , Canaux potassiques calcium-dépendants de grande conductance/physiologie , Myomètre/physiologie , Contraction utérine/physiologie , Benzimidazoles/pharmacologie , Femelle , Humains , Techniques in vitro , Canaux KATP/effets des médicaments et des substances chimiques , Canaux potassiques calcium-dépendants de grande conductance/effets des médicaments et des substances chimiques , Modulateurs du transport transmembranaire/pharmacologie , Ocytocine , Pinacidil/pharmacologie , Grossesse , Contraction utérine/effets des médicaments et des substances chimiquesRÉSUMÉ
BACKGROUND: Monotherapy with aromatase inhibitors has no established role in premenopausal breast cancer in women and is an area of future exploration. MATERIALS AND METHODS: In this study, chemopreventive effects of anastrozole in the model of N-methyl-N-nitrosourea-induced premenopausal mammary carcinogenesis in female rats were evaluated. Anastrozole was dietarily administered at two concentrations: 0.05 mg/kg (ANA 0.05) and 0.5 mg/kg (ANA 0.5). Basic parameters of experimental carcinogenesis and side-effects on selected organs after anastrozole treatment in animals were assessed. RESULTS: In the ANA 0.5 group, anastrozole suppressed tumor incidence by 40% (p<0.05) and tumor frequency by 57% (p<0.01), as well as lengthening the latency period by 10 days (p=0.084) compared to control animals. Adverse effects of anastrozole on the genital system (uterus and vagina) and lipid and bone metabolism in rats were not found. Anastrozole did not alter serum concentrations of estradiol, testosterone or dehydroepiandrosterone in animals. An increase in the body weight gain of rats in the ANA 0.5 group compared with the controls (p<0.01) was observed. CONCLUSION: This study is the first about the antineoplastic effects of anastrozole in a model of premenopausal mammary carcinogenesis in female rats.