The basic parapharmaceuticals in the Polish diet include natural anti-oxidants - bioflavonoids found in berry fruit. They were proven to have the ability to regulate genetic transcription and increase the synthesis of nitric oxide which counteracts dysfunction of the vascular endothelium. They also display anti-oxidant action through the inhibiting effect on cyclooxygenase - COX-2, and increase the level of adiponectin. We have also more and more proof of the important biological role of short-chained fatty acids formed as a result of fermentation of fibre by probiotic bacteria. Through their effects on peroxisome proliferators activated receptors (PPAR), butyric and propionic acids may reduce the expression of adhesion molecules and exert anti-inflammatory action both in the gastrointestinal tract as well as systemically.
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Adhesion and migration of leukocytes into the surrounding tissue are crucial steps in inflammation, immunity and atherogenesis. Expression of cell adhesion molecules by endothelial cells plays a role in these processes. Propionate is a naturally occurring short chain fatty acid produced by bacterial fermentation of dietary fibre. High intake of dietary fibre has been associated with an improved bowel function and with a reduced risk of cardiovascular disease. However, the molecular mechanisms responsible for these effects remain unknown. In this study, the effects of propionate on the expression of endothelial leukocyte adhesion molecules by cytokine-stimulated human umbilical vein endothelial cells (HUVEC) were investigated. Pretreatment of HUVEC with propionate significantly inhibited the tumor necrosis factor-alpha (TNF-)-induced expression of vascular cell adhesion molecule-1 (VCAM-1) and intracellular adhesion molecule-1 (ICAM-1) in a time- and dose-dependent manner. At 10 mM, propionate also inhibited the interleukin-1 (IL-1)-mediated VCAM-1 and ICAM-1 expression, with the latter effect being more pronounced, as well as decreased the TNF--induced VCAM-1 and ICAM-1 mRNA expression in a similar manner. The decrease in VCAM-1 and ICAM-1 expression was associated with a reduction of adherence of monocytes and lymphocytes to the cytokine-stimulated HUVEC. In addition, propionate significantly inhibited the TNF--induced activation of nuclear factor-kappa B (NF-B) and significantly increased the expression of peroxisome proliferator-activated receptor alpha (PPAR) in HUVEC. These results demonstrate that propionate may have antiinflammatory and possibly antiatherogenic properties. Our findings warrant further investigation into the therapeutic effects of propionate on a number of pathological events involving leukocyte recruitment.
Wehr, H., Naruszewicz, M., Nowicka, G. and Dziedziak, W.: Influence of experimental diets on cholesterol and triglyceride levels of rabbit blood serum lipoproteins. Acta physiol, pol., 1938. 39 (3): 202-206. Groups of rabbits were fed for six weeks various diets: standard died + ethanol, high-cholesterol diet and a high-cholesterol +: ethanol one. During the next six weeks every diet was supplemented with a fresh vegetable (carrot). Cholesterol and triglycerides were determined in the whole serum and in lipoprotein fractions. In rabbits fed standard diet ethanol caused a moderate elevation of VLDL cholesterol and triglyceride and LDL cholesterol levels. In animals on high-cholesterol diet cholesterol and triglyceride conćentrations in these fractions were very high. Simultaneous consumption of large amounts of cholesterol and of ethanol resulted in a greater rise of cholesterol concentration in the whole serum and in VLDL and LDL fraction than did high-cholesterol diet alone. Addition of carrot caused a pronounced reduction of serum cholesterol concentration in animals fed all kinds of diets. The reduction concerned mainly VLDL.