Fucoxanthin and lipid metabolism: A minireview.

AIMS: Accumulating data suggest that food supplementation with seaweeds which traditionally are an important part of food culture in South-East Asian countries might lead to essential health benefits. In this short review, we summarize findings from experimental studies on the effects of fucoxanthin (a carotenoid derived from brown seaweeds) on lipid metabolism, adiposity, and related conditions and discuss the possible underlying mechanisms. DATA SYNTHESIS: Supplementation of fucoxanthin or its derivatives consistently attenuated body and visceral fat weight gain, lipid accumulation in the liver, decreases insulin resistance, and improves the plasma lipid profile in rodents fed a high-fat diet. It should however be noted that in diabetic/obese KK-Ay mice with genetically compromised insulin signaling, fucoxanthin might increase the plasma levels of cholesterol and low-density lipoproteins. The anti-obesity effects of fucoxanthin are apparently mediated by the hormones leptin and adiponectin through their common target AMK-activated protein kinase, resulting in downregulation of lipogenic enzymes and upregulation of lipolytic enzymes. Fucoxanthin also suppresses adipocyte differentiation and induces the expression of uncoupling proteins in visceral adipose tissue. CONCLUSIONS: The results of experimental studies suggest that consumption of fucoxanthin and its derivatives as nutritional supplements is a promising option for prevention and treatment of obesity and a wide variety of related pathologies, including metabolic syndrome, type 2 diabetes, and heart disease. Yet, clinical trials are warranted to assess a therapeutic value of fucoxanthin.

[Effects of relic microorganism B. sp. on development, gaseous exchange, spontaneous motor activity, stress resistance and survival of Drosophila melanogaster].

The effect of relic microorganism B. sp., living in severe environment of Siberian permafrost during thousands and millions of years, on development and stress resistance of Drosophila melanogaster has been studied. In manipulating with such objects with practically "eternal life span", molecular carriers of the unprecedented longevity potential and possibilities of their transmission to other biological objects should primarily be addressed. Here we discuss for the first time the influence of B. sp. application on development, survival, stress resistance and the gross physiological predictors of aging rate in D. melanogaster. To establish optimal and toxic doses, wide range of B. sp. concentrations were tested (1-500 million cells of B. sp. per 1 ml of the flies feeding medium). Surprisingly, no toxic effects of B. sp. could be registered even on such a "sensitive" model as the developing larvae. In fact, the rate of development, survival and body mass gradually increased with elevation of B. sp. concentration. The gain of higher body mass within shorter periods of development could indicate enhanced anabolic and/ or declined catabolic effects of B. sp. Higher motor activity and gaseous exchange rates were observed in imagoes developed on the mediums with B. sp. application. Survival of these flies at the heat shock (30 min at 38 degrees C) and ultraviolet irradiation (60 min, 50W UV lamp) was increased, indicating elevated stress resistance, apparently due to stimulation of DNA-repair and chaperone-mediated protection of macromolecules. Further research is clearly warranted to identify more efficient anti-stress and antiaging preparations and schemes of B. sp. application on models of laboratory mammals and human cell cultures.

[The activity of gas metabolism, thermoregulation, and antioxidant enzymes in aging C57Bl/6 mice].

The distribution type and correlative links between physiological and biochemical indices characterizing functional condition of the systems of gaseous exchange (V(O2) and V(CO2)), thermoregulation (body temperature and coefficient of thermoconductivity) and antioxidant defense have been studied in 62 young (3-5 mo.) and 58 old (23-26 mo.) male C57Bl/ 6 mice. The coefficients of variation differed significantly depending on the variable but not the age-group. Mean values of V(O2) and V(CO2), body temperature and thermoconductivity, but not activities of the antioxidant enzymes, declined in aging. Moreover, the activities of catalase, glutathione-peroxidase and glutathionereductase, i.e. enzymes involved in regulation of hydrogen peroxide level, increased in aging. The correlations between V(O2) and V(CO2), V(O2) and body temperature or V(O2) and the liver pH, as well as between the antioxidant enzyme activities exhibited little age-changes. However, three-dimensional non-linear models revealed significant age-changes in relations between the studied variables.

[Catalase and glutathione-peroxidase: qualitatively different correlations with the rate of oxygen consumption]. / Katalaza i glutationperokxidaza: kachestvenno razlichnaia korreliatsiia so skorost'iu potrebleniia kisloroda.

Correlative relations of the liver supernatant enzymatic activity of catalase (CAT) and glutathione-peroxidase (GP) with the velocities of oxygen consumption (VO2) and carbon dioxide exhalation (VCO2) were analyzed by the two- and three-dimensional linear and non-linear statistical methods in mice. It is shown that despite the close functions, CAT and GP, nevertheless, exhibit opposite correlative and regressive links with the gaseous exchange indices. As was found by the pairwise linear method, the activity correlation with VO2 was positive for CAT, but negative for GP. The opposite patterns of correlation were also apparent under the three-dimensional non-linear analysis.

[Correlative links between superoxide dismutase, catalase and glutathione peroxidase activities in mouse liver]. / Korreliativnye sviazi mezhdu aktivnost'iu superoksiddismutazy, katalazy i glutationperoksidazy pecheni myshei.

Qualitative and quantitative differences in correlative and regressive links between superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase were assessed in the mice liver by two- and three-dimensional statistical methods. Paired linear correlation analysis indicated SOD-CAT tandem as the correlatively acting enzymatic pair. Three-dimensional analysis revealed uniform response surfaces which exhibited higher activities at disproportional values of the other two and lower activities at proportional activities of the other two enzymes. The direct effect of the enzymes on each other was positive [table: see text] while the effect of their product was always negative.

[Correlation between gaseous exchange rate, body temperature, and mitochondrial protein content in the liver of mice]. / Koreliatsiina zalezhnist' mizh hazoobminom, temperaturoiu tila ta vmistom mitokhondrial'noho bilka pechinki myshei.

Correlative and regressive relations between the gaseous exchange, thermoregulation and mitochondrial protein content were analyzed by two- and three-dimensional statistics in mice. It has been shown that the pair wise linear methods of analysis did not reveal any significant correlation between the parameters under exploration. However, it became evident at three-dimensional and non-linear plotting for which the coefficients of multivariable correlation reached and even exceeded 0.7-0.8. The calculations based on partial differentiation of the multivariable regression equations allow to conclude that at certain values of VO2, VCO2 and body temperature negative relations between the systems of gaseous exchange and thermoregulation become dominating.

[Characteristics of the effect of implantation of the human ApoA1 gene on the condition of hepatocytes in rats of varying age]. / Osobennosti vliianiia implantatsii gena ApoA1 cheloveka na sostoianie gepatotsitov krys raznogo vozrasta.

The results obtained show the essential changes in functional state of hepatocyte's plasmatic membrane due to the implantation of human ApoA1 gene to the rat liver. The changes in phospholipid composition, hyperpolarization, increase in activity of membrane bound enzymes, cytochrome P-450 and biosynthesis of liver total proteins have been found. The essential changes characterizing cell effect were more marked in the adult rats, and membrane effect in the old ones.

[The effect of the implantation of the human apo A-I gene on the function of the hepatocyte plasma membrane in rats]. / Vliianie implantatsii gena apoAI cheloveka na sostoianie plazmaticheskoi membrany gepatotsitov krys.

Evidences are given that implantation of human apo A-I gene to experimental animals induces essential changes in the functional state of hepatocyte plasmatic phospholipid composition, hyperpolarization development, as well as changes in the Na, K-ATPase and adenylate cyclase activities. The presence of generalized cell reaction is evidenced from the fact than biosynthesis of summary proteins gets enhanced during the above changes.

[Effect of reduced caloric intake on circadian rhythm of gas exchange and heat production in old rats]. / Vliianie ogranichennogo po kaloriinosti ratsiona na tsirkadnyi rhythm gazoobmena i teploproduktsii u starykh krys.

Fifty male Wistar rats at the age of 24 months were divided into two equal groups (test and control). Test animals received a 2-fold reduced ration. At the age of 32 months all the animals were examined for gas exchange and heat production circadian rhythm. The test animals were 3 hours fast compared to controls in maximal values of gas exchange, rectal temperature and heat conductivity, while relevant mean daily values did not change. The circadian rhythm of the above values in test animals corresponded to that of younger rats indicating higher performance of the underlying mechanisms and explaining longer survival of the test rats, who had less rates of gas exchange and rectal temperature variability and lower heat circulation coefficient.

[Effect of emotional-pain stress on RNA and protein synthesis in rats of different age]. / Vliianie émotsional'no-bolevogo stressa na sintez RNK i belka raznogo vozrasta.

The intensity of RNA and protein biosynthesis is studied in different tissues as well as in active and low-active fractions of liver chromatin, when adult and old rats are subjected to emotional-painful stress during 3 days. Significant stimulation of RNA and protein biosynthesis in chromatin fractions in liver and total RNA and protein in adrenals and hypothalamus is observed.

[Effect of adrenergic and cholinergic blocking agents on the intensity of RNA and protein biosynthesis in the liver of adult and old rats]. / Vliianie adreno- i kholinoblokatorov na intensivnost' biosinteza RNK i belka pecheni vzroslykh i starykh krys.

The uptake of labelled precursors of RNA and protein and their incorporation into corresponding macromolecules were studied in the liver of adult and old rats after pharmacological blockade of the adreno- and cholinoreceptors. The data obtained suggest direct neural regulation of transcription and translation intensity as well as the weakening of these mechanisms in aging.

[Lipid peroxidation and the life span of Drosophila melanogaster]. / Perekisnoe okislenie lipidov i prodolzhitel'nost' zhizni u drozofil Drosophila melanogaster.

Studies have been made on the relationship between incubation temperature (20-30 degrees C) of D. melanogaster and the life span as well as the content of various products of lipid peroxidation. It was shown that the increase in the environmental temperature results in the decrease in the life span, the content of unsaturated fatty acids and conjugated hydroxyperoxids; ketodienic content increases. Strong correlation was observed between the life span and the content of peroxidation products. As it is indicated by coefficients of bifactorial linear regression with interaction, conjugated hydroperoxids and ketodiens exert negative influence on the life span. Their combined effect on the life span is less significant than the sum of their separate effects, which indicates the existence of common "canals" of their influences on the life span.

[Distribution of the species-specific lifespan in various taxonomic animal groups]. / Raspredelenie vidovoi prodolzhitel'nosti zhizni v razlichnykh taksonomicheskikh gruppakh zhivotnykh.

A distribution of specific lifespan has been studied in different taxonomic groups of animals. A positive skewness has been observed in animal kingdom as well as in smaller taxonomic groups. The skewness is higher in groups with relatively short lifespan (Insecta, Rotatoria, Mollusca). A coefficient of variation and excess is also higher in the above groups. A comparison of these coefficients with paleontological age of the group allows to conclude that evolutionary progress of animals was accompanied by the increase in skewness, variation and excess of specific lifespan distribution.

[Effect of electrostimulation of the hypothalamus on protein biosynthesis in organs of adult and aged rats]. / Vliianie élektrostimuliatsii gipotalamusa na biosintez belka v raznykh organakh vzroslykh i starykh krys.

The effect of hypothalamus electrical stimulation on total protein biosynthesis was studied in skeletal muscle, heart, liver, adrenal cortex and thyroid gland of adult rats. In adult animals hypothalamus stimulation provokes a pronounced increase in 3H-leucine incorporation into total protein of all tissues, as well as into liver chromatin proteins. No significant changes were observed in protein biosynthesis when hypothalamus of old rats was stimulated. This can serve as evidence of age-related decrease in the ability of the hypothalamus to stimulate protein synthesis in peripheral tissues.

[Effect of hydrocortisone on RNA synthesis in the liver of rats of different ages]. / Vliianie gidrokortizona na sintez RNK v pecheni krys raznogo vozrasta.

Hydrocortisone effect on the transcription intensity of several RNA syntheses in the liver of rats of different age was studied in vivo and in vitro. It was shown that hydrocortisone injection to young and adult animals leads to marked stimulation of RNA synthesis in hepatocytes, manifested in increased specific radioactivity of RNA fractions or enhanced RNA-polymerase A and B activities. In old rats the intensity of the nuclear precursor synthesis of ribosome RNA is also significantly grows under hormone influence, whereas the informative RNA intensity does not markedly change.

[Relation between membrane potential changes and DNA, RNA and protein synthesis in regenerating liver cells after partial hepatectomy]. / O sviazi izmenenii velichiny membrannogo potentsiala i sinteza DNK, RNK i belka v kletkakn regeneriruiushchei pecheni posle chastichnoi gepatéktomii.

Variations in the membrane potential and in DNA, RNA and protein synthesis were studied in experiments on rats at varying times after hepatectomy. Hyperpolarization of the hepatocyte plasmatic membrane was shown to develop during liver regeneration along with activation of DNA, RNA and protein synthesis. Actinomycin D prevented the development of hyperpolarization and activation of RNA and protein synthesis. Administration of liver filtrates from hepatectomized rats to intact recipients induced hyperpolarization of liver cells. Activation of protein biosynthesis following hepatectomy resulted in hyperpolarization of the cell membrane, this action being mediated via formation of a specific membrane-active factor.