Supraphysiological dosages of vitamins and their implications in man

Summary Some recent evidence on the benefits and hazards of elevated dosages of vitamins is summarized. Special emphasis is given on the safety of vitamins A, D, K₁ and B₆. Furthermore, the possibly beneficial effects of vitamins for athletic performance as well as the preventive potential of antioxidative vitamins and of carotenoids against cancer are discussed.     

You are what you eat, and so are your children: the impact of micronutrients on the epigenetic programming of offspring

The research field of fetal programming has developed tremendously over the years and increasing knowledge suggests that both maternal and paternal unbalanced diet can have long-lasting effects on the health of offspring. Studies implicate that macronutrients play an important role in fetal programming, although the importance of micronutrients is also becoming increasingly apparent. Folic acid and vitamins B2, B6 and B12 are essential for one-carbon metabolism and are involved in DNA methylation. They can therefore influence the programming of the offspring’s epigenome. Also, other micronutrients such as vitamins A and C, iron, chromium, zinc and flavonoids play a role in fetal programming. Since it is estimated that approximately 78 % of pregnant women in the US take vitamin supplements during pregnancy, more attention should be given to the long-term effects of these supplements on offspring. In this review we address several different studies which illustrate that an unbalanced diet prior and during pregnancy, regarding the intake of micronutrients of both mother and father, can have long-lasting effects on the health of adult offspring.     

Les tests microbiologiques pour la détermination des vitamines

Summary The qualities required by a microorganism to work as test object are studied, so as the utilized methods to measure development.The different, watersoluble vitamins from the group B: thiamin, riboflavin, nicotinic acid, adermin (pyridoxin), pantothenic acid, -alanin, biotin, p-aminobenzoic acid, mesoinositol, enable the creation of a useful test with a selected microorganism.The problem of the vitaminic factors of the soil is one of those which can only be studied with help of microbiological tests. The presence of vitamins in the soil is proved. Their origin is discussed. Their action and that of vitamins voluntary added to the soil is studied. It is shown that the qualities of soil and manures have a marked influence on the thiamin rate of the studied plant.A cycle is suggested to show how the action of growth factors enable to understand the natural relations existing between the auxo-heterotrophic and the auxo-autotrophic organisms. The growth factors of the soil participate to the biological balance ruling life in and on the soil. The necessity of an ecological vitaminology is being considered.     

Die biologische Bedeutung der Vitamine

Summary The vital importance of the vitamins resides in theircoferment function, which enables them to catalyse enzymatic processes in living tissues. The term coferment is used in this connection to designate organic compounds of relatively low molecular weight, which in conjunction with the specific proteinous apoferments bring about the transformation of definite substrates. The vitamins are, however, catabolized like ordinary substrates when they come into contact with enzymatic systems in which they have no coferment function. This explains why normal life cannot be sustained, if the living organisms do not receive asnutritional factors the vitamins which they cannot synthesize. From a biochemical point of view not only exogenous hypo- or avitaminoses but all pathological changes may be regarded as the sequelae of disturbances in one or several enzymatic systems. The vitamins may exert a regulating influence also in these enzymatic disturbances which are not directly caused by vitamin deficiency. In such cases they will act asrèmedies.     

Vitamins and other metabolites in various sera commonly used for cell culturing

Many cell culture media use different sera to enhance growth. We assayed vitamins and some related metabolites in different sera and identified the concentration of: thiamin, biotin, folates, riboflavin, pantothenates, nicotinates, vitamins B6, B12, A, E, C, and carotenes and some related metabolites: biopterins, free inositol, free and total choline, total carnitines in chicken, horse, rabbit, goat, pig, calf, newborn calf, fetal calf and human sera. Results indicate that vitamin and metabolite content of different sera vary. Such variations could produce fluctuant effects on cell culturings if the metabolite content of the serum is not documented.     

Der Vitamingehalt der Moste verschiedener Rebenarten und -sorten

Summary The vitamins pyridoxine, pantothenic acid, niacin, and biotin in the musts of about 100 different species and varieties of vines were determined microbiologically. Musts of vines of the speciesVitis vinifera differed from wild species ofVitis by a lower amount of pyridoxine and pantothenic acid. The low content of these vitamins is suspected of being coupled with good cultural characters.      

Increased sensitivity to pentobarbital in rats fed a diet lacking flavonoids.

Pentobarbital-sensitivity is highly increased in rats fed a diet lacking flavonoids; sleeping time was found to be increased by 42 and 30% as compared with rats fed a normal diet. These studies confirm our previous statement according to which for the rat, benzopyrones are vitamins.     

Effect of alpha-tocopherol (vitamin E) on the utilization of vitamin A and induction of cytochrome P 450 in rats receiving DDT]

During detoxication processes of DDT, there is, in the Rat, interference between vitamins A and E (D.1.alpha-tocopherol acetate). Vitamin E spares retinal and has a slighter but significant influence on P 450 cytochrome induction. These results are discussed.     

Vitamintrennungen an Ionenaustauscherpapieren

Summary A simple new method is described for the separation of water-soluble vitamins, using ion exchange-papers.     

Chemical evidence for interactions between vitamins E and C

Experimental proof is provided for interactions between radicals of vitamin E/vitamin C as generated by air-oxidized lipids (liquid fraction of subcutaneous chicken fat). Using ESR spectroscopy, hydrogen atom exchange is shown to take place between vitamin C and the radical of vitamin E. Sequential consumption of these two vitamins in oxidized lipid, first vitamin C then vitamin E, is demonstrated by means of differential pulse polarography. These results elucidate the in vitro radical scavenging functions attributed to vitamin E and vitamin C as well as their synergism in lipid antioxidation.     

Aus der Chemie der Naturstoffe

Summary This lecture was held in Zürich to commemorate the 70^th birthday of Prof.Paul Karrer; it briefly outlines his life-work as a scientist and then reviews, in greater detail, some of his important work in various fields: vegetable dyestuffs (carotenoids), vitamins (particularly vitamins A, E and K) and curare alkaloids.As is the purpose of this lecture, a review is also given of the author's own work: ergot alkaloids and their derivatives; cardiac glycosides of squill, digitalis etc.; and finally, the most recent results of research on chlorophyll — the crystallization of natural chlorophylla andb after many years of endeavour.

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ErstePaul-Karrer-Vorlesung, gehalten im Rahmen der öffentlichen Feier zum 70. Geburtstag von Prof.Paul Karrer, am 25. April 1959 in der Aula der Universität Zürich.     

Protective effect of vitamins against trichothecene toxicity towards Saccharomyces cerevisiae

Several trichothecene mycotoxins were shown to inhibit the growth of Saccharomyces cerevisiae. This effect was most pronounced with the macrocyclic trichothecenes, especially verrucarin A. Much less growth inhibition was observed with T-2 toxin. Verrucarol, diacetoxyscirpenol, acetyl T-2 toxin, HT-2 toxin, T-2 tetraol and neosolaniol were inactive at a concentration of 75 micrograms of toxin per disc. Incubation of S. cerevisiae with verrucarin A together with vitamins resulted in a decrease in toxicity. Pyridoxine-HCl, Ca-pantothenate, thiamine-HCl and alpha-tocopheryl acetate were amongst the most potent of the vitamins tested which reversed growth inhibition, overcoming the inhibitory potential of the toxins.     

Chemical evidence for interactions between vitamins E and C

Summary Experimental proof is provided for interactions between radicals of vitamin E/vitamin C as generated by air-oxidized lipids (liquid fraction of subcutaneous chicken fat). Using ESR spectroscopy, hydrogen atom exchange is shown to take place between vitamin C and the radical of vitamin E. Sequential consumption of these two vitamins in oxidized lipid, first vitamin C then vitamin E, is demonstrated by means of differential pulse polarography. These results elucidate the in vitro radical scavenging functions attributed to vitamin E and vitamin C as well as their synergism in lipid antioxidation.The authors very much thank Dr A. Dieffenbacher and P. Ducret for the preparation of the chicken fat fraction.     

Wirkung der Glutaminsäure auf die experimentelle Isoniazid-Schädigung peripherer Nerven bei Ratten

Summary Glutamic acid does not, either in small or in large doses, inhibit the degeneration of the medullary sheath of peripheral nerves in rats, induced within 15 days by addition of 0.25% of isoniazid to their diet. The detoxicating effect of glutamic acid, as described byCedrangolo ¹, thus only applies to the general toxic symptoms of the acute INH-intoxication, as is the case for vitamins B₂, B₁₂, A, E, K, and niacinamide.     

Effects of storage and processing on the nutritive value of certain Nigerian foods

The effects of storage and processing on the nutritive value of two Nigerian foods--raw cowpea (Vigna unguiculata) flour and palm oil, have been investigated. Increased retention of both thiamine and riboflavin as a result of increased water activity (Aw) were recorded for cowpea flour stored for 6 months. A storage temperature of 5 degrees C led to minimal losses of both vitamins in the stored flour. Differences in physico-chemical characteristics were observed between palm oil produced by the traditional method and that produced by a modern commercial method. Increasing Aw led to decreasing loss of unsaturation in the traditionally-produced palm oil during 4-week storage at ambient temperature (25 degrees C).     

Effect of aspirin and vitamins C and E on synovial rheumatoid arthritic and other cells.

Normal and rheumatoid arthritic human synovial cells, normal rat muscle and bone cells, were cultured with combinations of aspirin (acetylsalicytic acid), vitamins C and E. Aspirin reduced percent growth of all cells by about 1/5 relative to controls. High vitamin C eradicated arthritic cells. In combinations, vitamin C was most important in eradicating arthritic cells. A low-vitamin C combination was most effective in reducing arthritic cell populations, while having little effect on normal cells. Vitamin E retarded but did not prevent the action of vitamin C.     

Effects of storage and processing on the nutritive value of certain Nigerian foods

Summary The effects of storage and processing on the nutritive value of two Nigerian foods-raw cowpea (Vigna unguiculata) flour and palm oil, have been investigated. Increased retention of both thiamine and riboflavin as a result of increased water activity (A_w) were recorded for cowpea flour stored for 6 months. A storage temperature of 5°C led to minimal losses of both vitamins in the stored flour. Differences in physico-chemical characteristics were observed between palm oil produced by the traditional method and that produced by a modern commercial method. Increasing A_w led to decreasing loss of unsaturation in the traditionally-produced palm oil during 4-week storage at ambient temperature (25°C).     

Protective effect of vitamins against trichothecene toxicity towardsSaccharomyces cerevisiae

Summary Several trichothecene mycotoxins were shown to inhibit the growth ofSaccharomyces cerevisiae. This effect was most pronounced with the macrocyclic trichothecenes, especially verrucarin A. Much less growth inhibition was observed with T-2 toxin. Verrucarol, diacetoxyscirpenol, acetyl T-2 toxin, HT-2 toxin, T-2 tetraol and neosolaniol were inactive at a concentration of 75 g of toxin per disc. Incubation ofS. cerevisiae with verrucarin A together with vitamins resulted in a decrease in toxicity. Pyridoxine-HCl, Ca-pantothenate, thiamine-HCl and -tocopheryl acetate were amongst the most potent of the vitamins tested which reversed growth inhibition, overcoming the inhibitory potential of the toxins.9 December 1986The authors thank Dr J. Behrend, Makor Company, Israel, for a generous gift of verrucarin A and roridin A.     

Effect of aspirin and vitamins C and E on synovial rheumatoid arthritic and other cells

Summary Normal and rheumatoid arthritic human synovial cells, normal rat muscle and bone cells, were cultured with combinations of aspirin (acetylsalicytic acid), vitamins C and E. Aspirin reduced percent growth of all cells by about 1/5 relative to controls. High vitamin C eradicated arthritic cells. In combinations, vitamin C was most important in eradicating arthritic cells. A low-aspirin, low-vitamin C combination was most effective in reducing arthritic cell populations, while having little effect on normal cells. Vitamin E retarded but did not prevent the action of vitamin C.Acknowledgment. This work was supported by NRC grant No. A 6445 to Dr Bhakthan, Department of Kinesiology, Simon Fraser University.     

Expression and function of nuclear receptor co-activator 4: evidence of a potential role independent of co-activator activity

Nuclear receptor coactivator 4 (NcoA4), also known as androgen receptor-associated protein 70 (ARA70), was initially discovered as a component of Ret-Fused Gene expressed in a subset of papillary thyroid carcinomas. Subsequent studies have established NcoA4 as a coactivator for a variety of nuclear receptors, including peroxisome proliferator activated receptors α and γ, and receptors for steroid hormones, vitamins D and A, thyroid hormone, and aryl hydrocarbons. While human NcoA4 has both LXXLL and FXXLF motifs that mediate p160 coactivator nuclear receptor interactions, this ubiquitously expressed protein lacks clearly defined functional domains. Several studies indicate that NcoA4 localizes predominantly to the cytoplasm and affects ligand-binding specificity of the androgen receptor, which has important implications for androgen-independent prostate cancer. Two NcoA4 variants, which may exert differential activities, have been identified in humans. Recent studies suggest that NcoA4 may play a role in development, carcinogenesis, inflammation, erythrogenesis, and cell cycle progression that may be independent of its role as a receptor coactivator. This review summarizes what is currently known of the structure, expression, regulation, and potential functions of this unique protein in cancerous and non-cancerous pathologies.