Lester Packer

Biochemical adaptation of mitochondria, muscle, and whole-animal respiration to endurance training.

The experimental intervention of exercise training has been used to study mitochondrial biosynthesis, and the physiologic integration of subcellular, cellular, and whole-animal energetics. Gross mitochondrial composition was unchanged in rat muscle by a 10-week program of endurance treadmill running. The mitochondrial concentration of iron-sulfur clusters, cytochromes, flavoprotein, dehydrogenases, oxidases, and membrane protein and lipid, as well as the ratios of each component to the others, maintained constant proportions. The mitochondrial content of muscle, however, increased by approximately 100% as did absolute tissue oxidative capacity. The soluble portions of mitochondria maintained a constant total protein content and mass, relative to the membrane fraction, despite adaptive changes in the specific activities of some citric acid-cycle enzymes. Mitochondria from endurance-trained muscles generated normal transmembrane potentials, ADP/O ratios, and respiratory control ratios. Muscle oxidase activity was highly correlated (r = 0.92) with endurance capacity, which increased 403%. Whole-animal maximal O2 consumption (VO2max), however, increased only 14% and was a relatively poor predictor of endurance. Thus, mitochondrial factors, rather than VO2max, must play an important role in dictating the limits of endurance activity. Conversely, VO2max was strongly related to the maximal intensity of work which could be attained aerobically (r = 0.82). Comparison of O2 consumption at the mitochondrial, muscle, and whole-animal levels revealed that maximal muscle oxidase activity was not an absolute limitation to VO2max: It is concluded that other factors intervene to control the percentage of muscle O2 consumption capacity which may be utilized during exercise.

mRNA expression profile of a human cancer cell line in response to Ginkgo biloba extract: induction of antioxidant response and the Golgi system.

Supplementation of diets with plant extracts for health and prevention of degenerative diseases is popular. However the molecular basis of their therapeutic potentials are poorly defined. We hypothesized that in vitro assays that enable quantitative analysis of the gene expression profiles combined with targeted biochemical analysis can identify the potential effects of phytochemicals. The hypothesis was tested by application of GeneChips to define mRNA expressions of a human bladder cancer cell line incubated with a flavonoid containing extract of Ginkgo biloba leaves. The analysis of the transcriptional response revealed a net activation of transcription. Functional classification of the affected mRNAs showed the largest changes in the abundance of mRNAs for intracellular vesicular transport, mitochondria, transcription and antioxidants. The transcripts for hemeoxygenase-1, mitochondrial superoxide dismutase and the regulatory subunit of γ-glutamyl-cysteinyl synthetase and their encoded proteins were elevated. The extract also increased intracellular glutathione, the transcripts for DNA repair and synthesis, and decreased 3H-thymidine incorporation. These results demonstrate that a flavonoid containing extract initiates an adaptive transcriptional response that augments the “antioxidant status” of the cells and inhibits DNA damage. These in vitro studies using GeneChips demonstrated a promising strategy for identifying nutritional supplement induced cellular responses that may have a role in counteracting chronic human diseases.

Cytokine-induced glucose uptake in skeletal muscle: redox regulation and the role of α-lipoic acid

In L6 myotubes, glucose uptake stimulated by interferon (IFN)-γ or lipopolysaccharides (LPS) and a combination of LPS, IFN-γ, and tumor necrosis factor (TNF)-α was inhibited by the antioxidant pyrrolidinedithiocarbamate and potentiated in reduced glutathione (GSH)-deficient cells. Also, the stimulatory effect of LPS and IFN-γ individually, and of a combination of LPS, IFN-γ, and TNF-α, on glucose uptake was associated with an increased level of intracellular oxidants (dichlorofluorescein assay) and loss of intracellular GSH. Study of the individual effects of LPS, IFN-γ, and TNF-α as well as of a combination of the three activators provided evidence against a role of nitric oxide in mediating the stimulatory effect of the above-mentioned agents on glucose uptake. We also observed that the insulin-mimetic nutrient α-lipoic acid (LA; R-enantiomer) is able to stimulate glucose uptake in cytokine-treated cells that are insulin resistant. This study shows that cytokine-induced glucose uptake in skeletal muscle cells is redox sensitive and that, under conditions of acute infection that is accompanied with insulin resistance, LA may have therapeutic implications in restoring glucose availability in tissues such as the skeletal muscle.

Nutraceuticals in health and disease prevention

Nutraceuticals: The Link Between Nutrition and Medicine Hans K. Biesalski The Role of Vitamin E in the Emerging Field of Nutraceuticals Lester Packer and Stefan U. Weber S-Adenosylmethionine (SAMe): Preclinical and Clinical Studies in Depression Teodoro Bottiglieri S-Adenosyl-L-Methionine: The Healthy Joint Product Giorgio Stramentinoli Methyltetrahydrofolate: The Superior Alternative to Folic Acid John Scott Lycopene and Lutein: The Next Steps to the Mixed Carotenoids Robert M. Russell n-3 Polyunsaturated Fatty Acids from Fish: Effects on Coronary Artery Disease Erik Berg Schmidt and Jorn Dyerberg Lipoic Acid: A Multifunctional Nutraceutical Aalt Bast and Guido R. M. M. Haenen R-alpha-Lipoic Acid Klaus Kramer and Lester Packer Creatine: Physiology and Exercise Performance Klaus Kramer, Michael Weiss, and Heinz Liesen Plant Phenols and Cardiovascular Disease: Antioxidants and Modulators of Cell Response Fabio Virgili, Cristina Scaccini, Peter-Paul Hoppe, Klaus Kramer, and Lester Packer L(-)-Carnitine and Its Precursor gButyrobetaine Hermann Seim, Knut Eichler, and Hans-Peter Kleber Conjugated Linoleic Acid Werner G. Siems, Tilman Grune, Oliver Hasselwander, and Klaus Kramer Contributions of Different Types of Evidence Charles Hennekens The Brave New World of Foods That Make Health-Related Claims Stephen H. McNamara

Monochloramine Inhibits Phorbol Ester-inducible Neutrophil Respiratory Burst Activation and T Cell Interleukin-2 Receptor Expression by Inhibiting Inducible Protein Kinase C Activity

Monochloramine derivatives are long lived physiological oxidants produced by neutrophils during the respiratory burst. The effects of chemically prepared monochloramine (NH2Cl) on protein kinase C (PKC) and PKC-mediated cellular responses were studied in elicited rat peritoneal neutrophils and human Jurkat T cells. Neutrophils pretreated with NH2Cl (30–50 μm) showed a marked decrease in the respiratory burst activity induced by phorbol 12-myristate 13-acetate (PMA), which is a potent PKC activator. These cells, however, were viable and showed a complete respiratory burst upon arachidonic acid stimulation, which induces the respiratory burst by a PKC-independent mechanism. The NH2Cl-treated neutrophils showed a decrease in both PKC activity and PMA-induced phosphorylation of a 47-kDa protein, which corresponds to the cytosolic factor of NADPH oxidase, p47 phox . Jurkat T cells pretreated with NH2Cl (20–70 μm) showed a decrease in the expression of the interleukin-2 receptor α chain following PMA stimulation. This was also accompanied by a decrease in both PKC activity and nuclear transcription factor-κB activation, also without loss of cell viability. These results show that NH2Cl inhibits PKC-mediated cellular responses through inhibition of the inducible PKC activity.

Skeletal muscle and liver lipoyllysine content in response to exercise, training and dietary α‐lipoic acid supplementation

In human cells, α‐lipoic acid (LA) is present in a bound lipoyllysine form in mitochondrial proteins that play a central role in oxidative metabolism. The possible effects of oral LA supplementation, a single bout of strenuous exercise and endurance exercise training on the lipoyllysine content in skeletal muscle and liver tissues of rat were examined. Incorporation of lipoyl moiety to tissue protein was not increased by enhanced abundance of LA in the diet. Endurance exercise training markedly increased lipoyllysine content in the liver at rest. A bout of exhaustive exercise also increased hepatic lipoyllysine content. A significant interaction of exhaustive exercise and training to increase tissue lipoyllysine content was evident. In vastus lateralis skeletal muscle, training did not influence tissue lipoyllysine content. A single bout of exhaustive exercise, however, clearly increased the level of lipoyllysine ill the muscle. Comparison of tissue lipoyllysine data with that of free or loosely‐bound LA results showed a clear lack of association between the two apparently related parameters. Tightly protein‐bound lipoyllysine pool in tissues appeared to be independent of the loosely‐bound or free LA status in the tissue.

Bio-normalizer modulates interferon-γ-induced nitric oxide production in the mouse macrophage cell line RAW 264.7

Bio‐Normalizer, a natural health food supplement prepared from Carica papaya and some other medicinal plants was investigated to determine its effects on cellular nitric oxide (nitrogen monoxide, NO) production and inducible nitric oxide synthase (iNOS) expression. Bio‐Normalizer upregulated interferon (IFN)‐γ‐induced NO production by macrophages in a dose‐dependent manner. Such an effect of Bio‐Normalizer on NO production was not due to changes in the activity of iNOS. Reverse transcription‐potymerase chain reaction analysis revealed that the levels of iNOS mRNA were augmented by treatment of the cells with Bio‐Normalizer and IFN‐γ. The ability of Bio‐Normalizer to augment IFN‐γ‐induced iNOS mRNA expression was independent of any changes on the mRNA stability. Treatment of cells with Bio‐Normalizer alone did not affect NO production by macrophages. Tumor necrosis factor‐α and interleukin‐1β are involved in the induction of iNOS gene as well as the immune system. Bio‐Normalizer augmented the mRNA expression of these cytokines in the presence of IFN‐γ. This suggests that Bio‐Normalizer is not directly involved in the expression of iNOS, but shows synergistic interaction with IFN‐γ to induce NO synthesis.

[Mesityl]bacteriorhodopsin. The properties of an analogue of the purple membrane containing [mesityl]retinal as the chromophore

Abstract— A new synthesis of all‐trans‐[mesityl]retinal, II, (all‐trans‐3,7‐dimethyl‐9‐(2′,4′,6′‐trimethylphenyl)‐2,4,6,8,‐nonatetraenal) and 13‐cis‐[mesityl]retinal, VI, (3,7‐dimethyl‐9‐(2′4′6′‐trimethylphenyl)‐2Z,4E,6E,8E‐nonatetraenal) is reported. Combination of all‐trans‐[mesityl]retinal with bacterioopsin results in the formation of a synthetic membrane (Λmax 460) which has photocycling properties similar to the purple membrane although its cycling rate is very much slower. An M‐type intermediate can be trapped at ‐60°C. Photoreversal of the M‐intermediate to the wavelength of initial absorption is observed. Phototransformation of the initial [mesityl]bacteriorhodopsin is accompanied by conversion of the all‐frans to the 13‐cis‐isomer.

Determination of Dissolved Oxygen in Photosynthetic Systems and Protective Strategies Against its Toxic Effects in Cyanobacteria

In the study of the inhibitory effects of oxygen, photosynthetic organisms occupy a unique position. Unlike other biological systems, in which the cells are ordinarily exposed only to ambient O2 levels and often far below, the oxygenic photosynthetic cell produces its own oxygen from within. The O2 concentrations to which photosynthetic organisms are exposed, are often above those in the ambient air. Moreover, the energy utilized by the photosynthetizing cell is that of light. This energy, mainly at the ultraviolet and visible regions, can be harmful by itself, even without the risks involved with activation of molecular oxygen.