No abstract

Atherosclerosis and cancer are ranked among the most serious health problems in human medicine. Various predictive and etiological factors, biomarkers and molecular pathways of disease development and progression common to atherosclerosis and cancer suggest that the two most common diseases in worldwide dimension are far more closely aligned than previously believed. It is hypothesized that atherosclerosis and cancer are variants of a similar disease process. Shared disease progression in atherosclerosis and cancer is the emergence of similar novel approaches to therapy. On previous knowledge, it may be hypothesized that not only common approaches to therapy but also preventive strategies could be efficacious in both diseases. The results of in vitro and in vivo animal experiments, clinical and epidemiological studies and also the results of our experiments using animal experimental models of atherosclerosis and carcinogenesis indicate that probiotics, prebiotics, plants and their extracts and poly-unsaturated fatty acids could be effectively used in prevention of both atherosclerosis and colorectal cancer and decrease the disease risk. Future research should answer the question whether probiotic microorganisms and natural bioactive substances could effectively influence the molecular mechanisms in pathogenesis of atherosclerosis and cancer.

The aim of the present study was to evaluate the effect of the new probiotic strain Lactobacillus plantarum on chemically induced carcinogenesis in rats. Sprague dowley rats (n = 33) were divided into control and experimental groups and were fed a conventional laboratory diet. In the experimental group, rats were treated with the probiotic at the dose of 1 × 10 9 CFU (colonyforming units)/ml. Two weeks after the beginning of the trial, N,N-dimethylhydrazine (chemical carcinogen) injections were applied s.c. at the dose of 21 mg/kg b.w., 5 × weekly. At the end of the 8-month experimental period, faeces samples were taken from the rats and used for laboratory analysis. The counts of lactobacilli and coliforms and bacterial enzyme activity were determined. The probiotic strain L. plantarum as single species or in combination with oil (Lini oleum virginale) decreased the count of total coliforms and increased lactobacilli in faeces of rats. Application of probiotic microorganisms significantly (P < 0.05) decreased the activities of bacterial enzymes (β-galactosidase and β-glucuronidase) compared to the control group rats. The results of this study indicate that probiotic microorganisms could exert a preventive effect on colon carcinogenesis induced by N,N-dimethylhydrazine.

Natural bioactive supplements have been extensively studied as preventive agents. The aim of this study was to investigate the efficacy of inulin enriched with oligofructose and Hyppocastani extractum siccum as preventive agents of experimentally induced colon carcinogenesis in rats. Colon carcinogenesis was induced by N,N dimethylhydrazine (DMH) in a dose of 21mg/kg body weight s.c., five times at weekly intervals. Sprague Dawley rats (n = 45) were divided into a control group without DMH; control group with injected DMH; group receiving inulin and injected DMH; group receiving Hyppocastani extractum siccum and injected DMH; group receiving inulin and Hyppocastani extractum siccum and injected DMH. The beneficial effects of natural compounds were determined by analysis of caecal parameters such as pH, composition of microflora, activity of bacterial glycolytic enzymes and production of short-chain fatty acids (SCFA). The counts of coliforms were decreased in the groups receiving inulin enriched with oligofructose (P < 0.01), Hyppocastani extractum siccum (P < 0.001) and the combination of these supplements (P < 0.001). The counts of lactobacilli were significantly increased in all experimental groups receiving natural compounds (P < 0.01; P < 0.001). Experimental groups receiving natural compound alone and in combination resulted in a significant decrease in the activity of β-glucuronidase (P < 0.01; P < 0.001). Administration of inulin and Hyppocastani extractum siccum separately significantly increased the concentration of SCFA compared to the control group with DMH. The achieved results indicate the beneficial effect of prebiotics and plant extracts on metabolic processes in the colon and suggest that they could exert a preventive effect on colon carcinogenesis induced by DMH.Keywords: carcinogenesis; prebiotics; plant extract; prevention List of abbreviations DMH = N, N dimethylhydrazine; SCFA = short chain fatty acid; CRC = colorectal cancer; α-GAL = α-galactosidase;

It is well known that in patients with obstructive sleep apnea syndrome (OSAS) the apnea-hypopnea index (AHI) is significantly decreased during slow wave sleep (SWS). It used to be explained by the ability of SWS to stabilize the upper airways against collapse. Another explanation, which is the focus of the current study, is that it is just a result of high instability of SWS to obstructive apnea exposure, i.e. high susceptibility of SWS to transition into lighter sleep stages during exposure to obstructive apneas. A retrospective chart review was performed on 560 males who underwent an overnight polysomnography. Two hundred and eighty-seven patients were eligible for the study. They were divided into 3 groups according to different AHI level. All three groups had a higher SWS occurrence in the lateral position than in the supine position. A special fourth group of patients was created with severe OSAS in the supine position but with very mild OSAS in the lateral position. This group had, in the lateral position, (A) higher AHI in NREM sleep (4.1±3.1/h vs. 0.7±1.2/h, p<0.001) as well as (B) higher SWS occurrence (27.7±15.0 % vs. 21.4±16.2 % of NREM sleep, p<0.05), than the group with the lowest AHI in the study, i.e. AHI<5/h in NREM sleep. These data suggest that strong coincidence between SWS and low AHI is the result of the high instability of SWS to obstructive apnea exposure. The data also support the presence of SWS-rebound in OSAS patients in the lateral body position.