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665 KiB

Open AccessArticle

Synergistic Chondroprotective Effect of α-Tocopherol, Ascorbic Acid, and Selenium as well as Glucosamine and Chondroitin on Oxidant Induced Cell Death and Inhibition of Matrix Metalloproteinase-3—Studies in Cultured Chondrocytes

by Anne-Christi Graeser, Katri Giller, Heike Wiegand, Luca Barella, Christine Boesch Saadatmandi and Gerald Rimbach

Molecules 2010, 15(1), 27-39; https://doi.org/10.3390/molecules15010027 - 24 Dec 2009

Cited by 12 | Viewed by 14351

Abstract

Overproduction of reactive oxygen species and impaired antioxidant defence accompanied by chronic inflammatory processes may impair joint health. Pro-inflammatory cytokines such as interleukin-1β (IL-1β) and tumor necrosis factor alpha (TNF-α) stimulate the expression of metalloproteinases which degrade the extracellular matrix. Little is known [...] Read more.

Overproduction of reactive oxygen species and impaired antioxidant defence accompanied by chronic inflammatory processes may impair joint health. Pro-inflammatory cytokines such as interleukin-1β (IL-1β) and tumor necrosis factor alpha (TNF-α) stimulate the expression of metalloproteinases which degrade the extracellular matrix. Little is known regarding the potential synergistic effects of natural compounds such as α-tocopherol (α-toc), ascorbic acid (AA) and selenium (Se) on oxidant induced cell death. Furthermore studies regarding the metalloproteinase-3 inhibitory activity of glucosamine sulfate (GS) and chondroitin sulfate (CS) are scarce. Therefore we have studied the effect of α-toc (0.1–2.5 µmol/L), AA (10–50 µmol/L) and Se (1–50 nmol/L) on t-butyl hydroperoxide (t-BHP, 100–500 µmol/L)-induced cell death in SW1353 chondrocytes. Furthermore we have determined the effect of GS and CS alone (100–500 µmol/L each) and in combination on MMP3 mRNA levels and MMP3 secretion in IL-1β stimulated chondrocytes. A combination of α-toc, AA, and Se was more potent in counteracting t-BHP-induced cytotoxicity as compared to the single compounds. Similarly a combination of CS and GS was more effective in inhibiting MMP3 gene expression and secretion than the single components. The inhibition of MMP3 secretion due to GS plus CS was accompanied by a decrease in TNF-α production. Combining natural compounds such as α-toc, AA, and Se as well as GS and CS seems to be a promising strategy to combat oxidative stress and cytokine induced matrix degradation in chondrocytes. Full article

(This article belongs to the Special Issue Vitamins)

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139 KiB

Open AccessArticle

Production of β-Maltooligosaccharides of α- and δ-Tocopherols by Klebsiella pneumoniae and Cyclodextrin Glucanotransferase as Anti-Allergic Agents

by Kei Shimoda, Masaaki Akagi and Hiroki Hamada

Molecules 2009, 14(8), 3106-3114; https://doi.org/10.3390/molecules14083106 - 20 Aug 2009

Cited by 13 | Viewed by 10029

Abstract

The glycosylation of α- and δ-tocopherols using Klebsiella pneumoniae and cyclodextrin glucanotransferase (CGTase) was investigated. K. pneumoniae converted α- and δ-tocopherols into the corresponding β-glucosides in 10 and 8% yield, respectively. CGTase glycosylated α-tocopheryl β-glucoside to α-tocopheryl β-maltoside (51%) and α-tocopheryl β-maltotrioside (35%). [...] Read more.

The glycosylation of α- and δ-tocopherols using Klebsiella pneumoniae and cyclodextrin glucanotransferase (CGTase) was investigated. K. pneumoniae converted α- and δ-tocopherols into the corresponding β-glucosides in 10 and 8% yield, respectively. CGTase glycosylated α-tocopheryl β-glucoside to α-tocopheryl β-maltoside (51%) and α-tocopheryl β-maltotrioside (35%). On the other hand, δ-tocopheryl β-glucoside was converted into the corresponding β-maltoside (45%) and β-maltotrioside (29%) by CGTase. The β-glucoside of α-tocopherol, and β-glucoside and β-maltoside of δ-tocopherol showed inhibitory effects on IgE antibody production and on histamine release from rat peritoneal mast cells. Full article

(This article belongs to the Special Issue Vitamins)

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Review

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2029 KiB

Open AccessReview

Vitamin B₁₂: Unique Metalorganic Compounds and the Most Complex Vitamins

by Lucio Randaccio, Silvano Geremia, Nicola Demitri and Jochen Wuerges

Molecules 2010, 15(5), 3228-3259; https://doi.org/10.3390/molecules15053228 - 30 Apr 2010

Cited by 141 | Viewed by 26527

Abstract

The chemistry and biochemistry of the vitamin B₁₂ compounds (cobalamins, XCbl) are described, with particular emphasis on their structural aspects and their relationships with properties and function. A brief history of B₁₂, reveals how much the effort of chemists, biochemists [...] Read more.

The chemistry and biochemistry of the vitamin B₁₂ compounds (cobalamins, XCbl) are described, with particular emphasis on their structural aspects and their relationships with properties and function. A brief history of B₁₂, reveals how much the effort of chemists, biochemists and crystallographers have contributed in the past to understand the basic properties of this very complex vitamin. The properties of the two cobalamins, the two important B₁₂ cofactors Ado- and MeCbl are described, with particular emphasis on how the Co-C bond cleavage is involved in the enzymatic mechanisms. The main structural features of cobalamins are described, with particular reference to the axial fragment. The structure/property relationships in cobalamins are summarized. The recent studies on base-off/base-on equilibrium are emphasized for their relevance to the mode of binding of the cofactor to the protein scaffold. The absorption, transport and cellular uptake of cobalamins and the structure of the B₁₂ transport proteins, IF and TC, in mammals are reviewed. The B₁₂ transport in bacteria and the structure of the so far determined proteins are briefly described. The currently accepted mechanisms for the catalytic cycles of the AdoCbl and MeCbl enzymes are reported. The structure and function of B₁₂ enzymes, particularly the important mammalian enzymes methyltransferase (MetH) and methyl-malonyl-coenzymeA mutase (MMCM), are described and briefly discussed. Since fast proliferating cells require higher amount of vitamin B₁₂ than that required by normal cells, the study of B₁₂conjugates as targeting agents has recently gained importance. Bioconjugates have been studied as potential agents for delivering radioisotopes and NMR probes or as various cytotoxic agents towards cancer cells in humans and the most recent studies are described. Specifically, functionalized bioconjugates are used as “Trojan horses” to carry into the cell the appropriate antitumour or diagnostic label. Possible future developments of B₁₂ work are summarized. Full article

(This article belongs to the Special Issue Vitamins)

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159 KiB

Open AccessReview

An Update on Vitamin E, Tocopherol and Tocotrienol—Perspectives

by Maria Laura Colombo

Molecules 2010, 15(4), 2103-2113; https://doi.org/10.3390/molecules15042103 - 24 Mar 2010

Cited by 160 | Viewed by 22687

Abstract

Vitamin E, like tocotrienols and tocopherols, is constituted of compounds essential for animal cells. Vitamin E is exclusively synthesized by photosynthetic eukaryotes and other oxygenic photosynthetic organisms such as cyanobacteria. In order to prevent lipid oxidation, the plants mainly accumulate tocochromanols in oily [...] Read more.

Vitamin E, like tocotrienols and tocopherols, is constituted of compounds essential for animal cells. Vitamin E is exclusively synthesized by photosynthetic eukaryotes and other oxygenic photosynthetic organisms such as cyanobacteria. In order to prevent lipid oxidation, the plants mainly accumulate tocochromanols in oily seeds and fruits or in young tissues undergoing active cell divisions. From a health point of view, at the moment there is a great interest in the natural forms of tocochromanols, because they are considered promising compounds able to maintain a healthy cardiovascular system and satisfactory blood cholesterol levels. Some evidence suggests that the potency of the antioxidant effects may differ between natural or synthetic source of tocochromanols (vitamin E). Full article

(This article belongs to the Special Issue Vitamins)

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366 KiB

Open AccessReview

Synthesis and Use of Stable Isotope Enriched Retinals in the Field of Vitamin A

by Prativa B.S. Dawadi and Johan Lugtenburg

Molecules 2010, 15(3), 1825-1872; https://doi.org/10.3390/molecules15031825 - 15 Mar 2010

Cited by 10 | Viewed by 15657

Abstract

The role of vitamin A and its metabolites in the life processes starting with the historical background and its up to date information is discussed in the introduction. Also the role of 11Z-retinal in vision and retinoic acid in the biological [...] Read more.

The role of vitamin A and its metabolites in the life processes starting with the historical background and its up to date information is discussed in the introduction. Also the role of 11Z-retinal in vision and retinoic acid in the biological processes is elucidated. The essential role of isotopically enriched systems in the progress of vision research, nutrition research etc. is discussed. In part B industrial commercial syntheses of vitamin A by the two leading companies Hoffmann-La Roche (now DSM) and BASF are discussed. The knowledge obtained via these pioneering syntheses has been essential for the further synthetic efforts in vitamin A field by other scientific groups. The rest of the paper is devoted to the synthetic efforts of the Leiden group that gives an access to the preparation of site directed high level isotope enrichment in retinals. First the synthesis of the retinals with deuterium incorporation in the conjugated side chain is reviewed. Then, ¹³C-labeled retinals are discussed. This is followed by the discussion of a convergent synthetic scheme that allows a rational access to prepare any isotopomer of retinals. The schemes that provide access to prepare any possible isotope enriched chemically modified systems are discussed. Finally, nor-retinals and bridged retinals that give access to a whole (as yet incomplete) library of possible isotopomers are reviewed. Full article

(This article belongs to the Special Issue Vitamins)

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173 KiB

Open AccessReview

Vitamins and Prostate Cancer Risk

by Krishna Vanaja Donkena, R. Jeffrey Karnes and Charles Y.F. Young

Molecules 2010, 15(3), 1762-1783; https://doi.org/10.3390/molecules15031762 - 12 Mar 2010

Cited by 9 | Viewed by 13771

Abstract

Prostate cancer (PC) is the second most common cancer in men worldwide. Its prevention and treatment remain a challenge to clinicians. Here we review the relationship of vitamins to PC risk. Many vitamins and related chemicals, including vitamin A, retinoids, several B vitamins, [...] Read more.

Prostate cancer (PC) is the second most common cancer in men worldwide. Its prevention and treatment remain a challenge to clinicians. Here we review the relationship of vitamins to PC risk. Many vitamins and related chemicals, including vitamin A, retinoids, several B vitamins, vitamin C, vitamin D and vitamin E have shown their anti-cancer activities as anti-oxidants, activators of transcription factors or factors influencing epigenetic events. Although laboratory tests including the use of animal models showed these vitamins may have anti-PC properties, whether they can effectively prevent the development and/or progression of PC in humans remains to be intensively studied subjects. This review will provide up-to-date information regarding the recent outcomes of laboratory, epidemiology and/or clinical trials on the effects of vitamins on PC prevention and/or treatment. Full article

(This article belongs to the Special Issue Vitamins)

404 KiB

Open AccessReview

Gene-Regulatory Activity of α-Tocopherol

by Gerald Rimbach, Jennifer Moehring, Patricia Huebbe and John K. Lodge

Molecules 2010, 15(3), 1746-1761; https://doi.org/10.3390/molecules15031746 - 12 Mar 2010

Cited by 116 | Viewed by 19325

Abstract

Vitamin E is an essential vitamin and a lipid soluble antioxidant, at least, under in vitro conditions. The antioxidant properties of vitamin E are exerted through its phenolic hydroxyl group, which donates hydrogen to peroxyl radicals, resulting in the formation of stable lipid [...] Read more.

Vitamin E is an essential vitamin and a lipid soluble antioxidant, at least, under in vitro conditions. The antioxidant properties of vitamin E are exerted through its phenolic hydroxyl group, which donates hydrogen to peroxyl radicals, resulting in the formation of stable lipid species. Beside an antioxidant role, important cell signalling properties of vitamin E have been described. By using gene chip technology we have identified α-tocopherol sensitive molecular targets in vivo including christmas factor (involved in the blood coagulation) and 5α-steroid reductase type 1 (catalyzes the conversion of testosterone to 5α-dihydrotestosterone) being upregulated and γ-glutamyl-cysteinyl synthetase (the rate limiting enzyme in GSH synthesis) being downregulated due to a-tocopherol deficiency. α-Tocopherol regulates signal transduction cascades not only at the mRNA but also at the miRNA level since miRNA 122a (involved in lipid metabolism) and miRNA 125b (involved in inflammation) are downregulated by α-tocopherol. Genetic polymorphisms may determine the biological and gene-regulatory activity of a-tocopherol. In this context we have recently shown that genes encoding for proteins involved in peripheral α-tocopherol transport and degradation are significantly affected by the apoE genotype. Full article

(This article belongs to the Special Issue Vitamins)

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654 KiB

Open AccessReview

Vitamin K₂ in Electron Transport System: Are Enzymes Involved in Vitamin K₂ Biosynthesis Promising Drug Targets?

by Michio Kurosu and Eeshwaraiah Begari

Molecules 2010, 15(3), 1531-1553; https://doi.org/10.3390/molecules15031531 - 10 Mar 2010

Cited by 122 | Viewed by 17703

Abstract

Aerobic and anaerobic respiratory systemsallow cells to transport the electrons to terminal electron acceptors. The quinone (ubiquinone or menaquinone) pool is central to the electron transport chain. In the majority of Gram-positive bacteria, vitamin K₂ (menaquinone) is the sole quinone in the [...] Read more.

Aerobic and anaerobic respiratory systemsallow cells to transport the electrons to terminal electron acceptors. The quinone (ubiquinone or menaquinone) pool is central to the electron transport chain. In the majority of Gram-positive bacteria, vitamin K₂ (menaquinone) is the sole quinone in the electron transport chain, and thus, the bacterial enzymes catalyzing the synthesis of menaquinone are potential targets for the development of novel antibacterial drugs. This manuscript reviews the role of vitamin K in bacteria and humans, and especially emphasizes on recent aspects of menaquinones in bacterial electron transport chain and on discoveries of inhibitor molecules targeting bacterial electron transport systems for new antibacterial agents. Full article

(This article belongs to the Special Issue Vitamins)

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634 KiB

Open AccessReview

Vitamin B₆: A Molecule for Human Health?

by Hanjo Hellmann and Sutton Mooney

Molecules 2010, 15(1), 442-459; https://doi.org/10.3390/molecules15010442 - 20 Jan 2010

Cited by 187 | Viewed by 34691

Abstract

Vitamin B₆ is an intriguing molecule that is involved in a wide range of metabolic, physiological and developmental processes. Based on its water solubility and high reactivity when phosphorylated, it is a suitable co-factor for many biochemical processes. Furthermore the vitamin is [...] Read more.

Vitamin B₆ is an intriguing molecule that is involved in a wide range of metabolic, physiological and developmental processes. Based on its water solubility and high reactivity when phosphorylated, it is a suitable co-factor for many biochemical processes. Furthermore the vitamin is a potent antioxidant, rivaling carotenoids or tocopherols in its ability to quench reactive oxygen species. It is therefore not surprising that the vitamin is essential and unquestionably important for the cellular metabolism and well-being of all living organisms. The review briefly summarizes the biosynthetic pathways of vitamin B₆ in pro- and eukaryotes and its diverse roles in enzymatic reactions. Finally, because in recent years the vitamin has often been considered beneficial for human health, the review will also sum up and critically reflect on current knowledge how human health can profit from vitamin B₆. Full article

(This article belongs to the Special Issue Vitamins)

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790 KiB

Open AccessReview

The Vitamin Nicotinamide: Translating Nutrition into Clinical Care

by Kenneth Maiese, Zhao Zhong Chong, Jinling Hou and Yan Chen Shang

Molecules 2009, 14(9), 3446-3485; https://doi.org/10.3390/molecules14093446 - 9 Sep 2009

Cited by 205 | Viewed by 19771

Abstract

Nicotinamide, the amide form of vitamin B₃ (niacin), is changed to its mononucleotide compound with the enzyme nicotinic acide/nicotinamide adenylyltransferase, and participates in the cellular energy metabolism that directly impacts normal physiology. However, nicotinamide also influences oxidative stress and modulates multiple pathways [...] Read more.

Nicotinamide, the amide form of vitamin B₃ (niacin), is changed to its mononucleotide compound with the enzyme nicotinic acide/nicotinamide adenylyltransferase, and participates in the cellular energy metabolism that directly impacts normal physiology. However, nicotinamide also influences oxidative stress and modulates multiple pathways tied to both cellular survival and death. During disorders that include immune system dysfunction, diabetes, and aging-related diseases, nicotinamide is a robust cytoprotectant that blocks cellular inflammatory cell activation, early apoptotic phosphatidylserine exposure, and late nuclear DNA degradation. Nicotinamide relies upon unique cellular pathways that involve forkhead transcription factors, sirtuins, protein kinase B (Akt), Bad, caspases, and poly (ADP-ribose) polymerase that may offer a fine line with determining cellular longevity, cell survival, and unwanted cancer progression. If one is cognizant of the these considerations, it becomes evident that nicotinamide holds great potential for multiple disease entities, but the development of new therapeutic strategies rests heavily upon the elucidation of the novel cellular pathways that nicotinamide closely governs. Full article

(This article belongs to the Special Issue Vitamins)

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