Miroslav Ferenčík

Beneficial health effects of milk and fermented dairy products — Review

Milk is a complex physiological liquid that simultaneously provides nutrients and bioactive components that facilitate the successful postnatal adaptation of the newborn infant by stimulating cellular growth and digestive maturation, the establishment of symbiotic microflora, and the development of gut-associated lymphoid tissues. The number, the potency, and the importance of bioactive compounds in milk and especially in fermented milk products are probably greater than previously thought. They include certain vitamins, specific proteins, bioactive peptides, oligosaccharides, organic (including fatty) acids. Some of them are normal milk components, others emerge during digestive or fermentation processes. Fermented dairy products and probiotic bacteria decrease the absorption of cholesterol. Whey proteins, medium-chain fatty acids and in particular calcium and other minerals may contribute to the beneficial effect of dairy food on body fat and body mass. There has been growing evidence of the role that dairy proteins play in the regulation of satiety, food intake and obesity-related metabolic disorders. Milk proteins, peptides, probiotic lactic acid bacteria, calcium and other minerals can significantly reduce blood pressure. Milk fat contains a number of components having functional properties. Sphingolipids and their active metabolites may exert antimicrobial effects either directly or upon digestion.

Modulatory effects of selenium and zinc on the immune system

Almost all nutrients in the diet play a crucial role in maintaining an “optimal” immune response, and both insufficient and excessive intakes can have negative consequences on the immune status and susceptibility to a variety of pathogens. We summarize the evidence for the importance of two micronutrients, selenium and zinc, and describe the mechanisms through which they affect the immune status and other physiological functions. As a constituent of selenoproteins, selenium is needed for the proper functioning of neutrophils, macrophages, NK cells, T lymphocytes and some other immune mechanisms. Elevated selenium intake may be associated with reduced cancer risk and may alleviate other pathological conditions including oxidative stress and inflammation. Selenium appears to be a key nutrient in counteracting the development of virulence and inhibiting HIV progression to AIDS. It is required for sperm motility and may reduce the risk of miscarriage. Selenium deficiency has been linked to adverse mood states and some findings suggest that selenium deficiency may be a risk factor in cardiovascular diseases. Zinc is required as a catalytic, structural and regulatory ion for enzymes, proteins and transcription factors, and is thus a key trace element in many homeostatic mechanisms of the body, including immune responses. Low zinc ion bioavailability results in limited immunoresistance to infection in aging. Physiological supplementation of zinc for 1–2 months restores immune responses, reduces the incidence of infections and prolongs survival. However, in every single individual zinc supplementation of food should be adjusted to the particular zinc status in views of the great variability in habitat conditions, health status and dietary requirements.

Hypocholesterolemic and immunostimulatory effects of orally applied Enterococcus faecium M-74 in man.

LyophilizedEnterococcus fœcium M-74 was administered to 12 adult subjects in a daily oral dose of 5× 109 bacteria for six weeks. The bacterium temporarily colonized the host intestine and its excretion with stool, persisted for five weeks after the last dose. The mean levels of serum cholesterol and LDL showed a biphasic effect—an elevation followed by a sharp decrease (on day 64 of investigation). The decrease corresponded in time with a significant increase in the ability to reduce iodonitrotetrazolium and superoxide production by peripheral neutrophils incubated with zymosan or phorbol myristate acetate, and also with an elevated production of IgG by peripheral blood mononuclear cells. Hence intake ofE. fœcium may have a hypocholesterolemic and immunostimulatory effect. It was also demonstrated thatE. fœcium significantly reduced the average activity of β-d-glucuronidase in stools.

Detection of drug-induced, superoxide-mediated cell damage and its prevention by antioxidants.

The mode of the cytotoxic activity of three benzo(c)fluorene derivatives was characterized. The observed morphological changes of lysosomes or variations of mitochondrial activity are assumed to be the consequence of cell protection against oxidative damage and/or the part of the damage process. To establish the relationship between the quantity of superoxide (O2*-) generated and the degree of damage resulting from O2*-, a simple system based on measurement of 3-(4-iodophenyl)-2-(4-nitrophenyl)-5-phenyltetrazolium chloride (INT) reductase activity in the presence of superoxide dismutase (SOD) was used. The functionality of the chosen battery of in vitro tests was proved using several known superoxide inducers: cyclosporin A (CsA) and benzo(a)pyrene (BP), as well as noninducers: citrinin (CT) and cycloheximide (CH). From the results followed that the cell growth tests are much better indices of toxicity than the other tests. The model system for the evaluation of the protective capacity of antioxidants against superoxide-induced cytotoxicity included simultaneous exposure of HeLa cells to cytotoxic drugs and to quercetin (Qe), an antioxidant of plant origin. The complete abolishment of the inhibition of cell proliferation and clonogenic survival was concluded to be due to the protective effect of the antioxidant. These observations correlated with the decrease of superoxide content as estimated by the INT-reductase assay in the presence of SOD using the same model system, as well as with the increase of intracellular SOD content and its activity.

Treatment of experimental adjuvant arthritis with the combination of methotrexate and lyophilizedEnterococcus faecium enriched with organic selenium

The efficacy of combination therapy with methotrexate (MTX) and probiotic bacteriaEnterococcus faecium enriched with organic selenium (EFSe) in rats with adjuvant arthritis was determined. Rats with adjuvant arthritis were given MTX (0.3 mg/kg 2-times weekly, orally); lyophilizedE. faecium enriched with Se (15 mg/kg, 5 d per week, orally); and a combination of MTX plus EFSe for a period of 50 d from the immunization. Levels of serum albumin, serum nitrite/nitrate concentrations, changes in hind paw swellling, arthrogram score, bone erosions, whole body bone mineral density (BMD) and bone mineral content (BMC) were assayed in the rats as variables of inflammation and destructive arthritis-associated changes. Treatment with MTX and with the combination MTX+EFSe significantly inhibited markers of both inflammation and arthritis. Significant differences in favor of combination therapy with MTX+EFSe as compared to MTX alone were seen in serum albumin concentration, hind paw swelling and arthrogram score. Reductions in radiographic scores were also more pronounced in the combination therapy group. Combination therapy, but not MTX alone, inhibited the reduction of BMD and BMC; treatment with lyophilized EFSe alone had no significant effect on adjuvant arthritis in rats. The potent therapeutic effect of low dosage MTX therapy in combination with lyophilized EFSe on adjuvant arthritis in rats was shown.

Inflammation - a Lifelong Companion. Attempt at a Non-Analytical Holistic View

Inflammation is a key component of the immune system. It has important functions in both defense and pathophysiological events maintaining the dynamic homeostasis of a host organism including its tissues, organs and individual cells. On the cellular level it is controlled by more than 400 currently known genes. Their polymorphisms and environmental conditions give rise to different genotypes in human population. Pro-inflammatory genotype, which dominates in the present population, may be advantageous in childhood but not in elderly people because it is characterized by an increased vulnerability to, and intensity of, inflammatory reactions. These reactions may be the possible reasons of chronic inflammatory diseases, especially in old age. Better understanding of complex molecular and cellular inflammatory mechanisms is indispensable for detailed knowledge of pathogenesis of many diseases, their prevention and directed drug therapy. Here we summarize the basic current knowledge on these mechanisms.

Amphiphilic detergents inhibit production of IgG and IgM by human peripheral blood mononuclear cells

All types (cationic, anionic and non-ionic) amphiphilic detergents significantly inhibited the production of both IgG and IgM by human peripheral blood mononuclear cells after polyclonal activation in vitro. The most potent inhibitors were didodecyldimethylammonium bromide (DDAB) and (1-methyldodecyl)dimethylamine N-oxide (2-ATDNO). They were able to suppress effectively the immunoglobulin production in 10(-3)-10(-8) M concentrations. A medium inhibitory effect was observed with Slovapon, sodium dodecyl sulphate (SDS) and Triton X-100, while Slovanik showed an inhibition only in concentrations higher than 10(-2)%. These results suggest that amphiphilic detergents may be characterized as potential immunotoxic substances with very negative effects on the immunoglobulin production.

Combination Treatment of Rat Adjuvant-Induced Arthritis with Methotrexate, Probiotic Bacteria Enterococcus faecium, and Selenium

Abstract: The effects of the probiotic bacteria Enterococcus faecium (EF) and selenium were studied on methotrexate (MTX) treatment in rats with adjuvant arthritis. Arthritic rats were treated orally with the following substances: lyophilized EF (15 mg/kg/day, 5 days a week), sodium selenite pentahydrate (SSe; 0.050 mg/kg containing 0.015 mg/kg selenium, 5 days a week), MTX (0.6 mg/kg/week), and their combinations for the period of 50 days from adjuvant application. Levels of serum albumin, serum nitrite/nitrate concentrations, hind paw swelling, arthrogram scores, whole‐body bone mineral density (BMD), and bone erosions were evaluated as markers of inflammation and destructive changes associated with arthritis. Long‐term preventive treatment with low‐dose MTX significantly inhibited the markers of both inflammation and arthritis. EF or SSe when administered singly or in combination had no significant effect on the given parameters in arthritic rats. EF, but not SSe, potentiated the beneficial effects of MTX, which resulted in a more significant reduction of hind paw swelling, arthrogram scores, and whole‐body BMD decrease. EF also had a tendency to improve the effect of MTX on serum albumin and nitrite/nitrate concentrations. Our results indicate that EF may increase the preventive effect of MTX treatment in rat adjuvant arthritis by improving its anti‐inflammatory and antiarthritic effects.

Lysosomal enzymes and metabolic activity of polymorphonuclear leukocytes from patients with systemic lupus erythematosus and from experimental animals after levamisole treatment.

The activity of β-d-glucuronidase (BDG) was lowered and the activity of myeloperoxidase (MPO) was elevated in polymorphonuclear leukocytes (PMNs) of SLE patients compared with normal subjects. After levamisole treatment, the activities of BDG, MPO, and lysozyme rose in PMNs of SLE patients. A higher activity of lysozyme was also observed in peritoneal PMNs of rabbits after levamisole administration. During incubation of human phagocytizing and non-phagocytizing PMNs, no effects of levamisole at concentrations of 10−3 to 10−5M were observed on the release of lysosomal enzymes. These concentrations of levamisole also did not influence INT reductase activity and production of superoxide by normal human PMNs in the presence of zymosan particles. These findings suggest that levamisole might have an effect on the actual level of lysosomal enzymes in PMNs rather than on their release.

Immunomodulatory effect of sodium dodecyl sulfate on human neutrophils and the human promyelocytic HL-60 cell line

The effect of sodium dodecyl sulfate (SDS), an anionic amphiphilic detergent, on the function of human neutrophils and of the human promyelocytic leukemia cell line HL-60 was investigated. SDS modulated the respiratory burst in human neutrophils and HL-60 cells which were stimulated with phorbol 12-myristate 13-acetate (PMA). In concentrations above 1 X 10(-6) M it also caused release of lysosomal enzymes (beta-D-glucuronidase, myeloperoxidase and lysozyme) from neutrophils. Our results demonstrate that SDS at concentrations 1 X 10(-6) M-1 X 10(-4) M strongly affect properties of human phagocytic cells.