Biofactors - Volume 13, issue 1-4

Authors: Joe A. Vinson,

Article Type: Research Article

Abstract: Tea is the second most consumed beverage around the world behind water. Epidemiological evidence points to both green and black tea consumption being protective with respect to heart disease. However, epidemiological evidence does not prove cause and effect and is potentially flawed by confounding variables. The recent evidence with respect to teas' beneficial effects from {\it in vitro} and {\it in vivo} studies in both animals and humans will be covered in this review. The comparative …benefits of green vs. black tea will be considered. Articles published through December, l999 will be included. Show more

Keywords: tea, antioxidant, heart disease, catechins

Citation: BioFactors, vol. 13, no. 1-4, pp. 127-132, 2000

Authors: Takanori Tsuda, | Fumihiko Horio, | Toshihiko Osawa,

Article Type: Research Article

Abstract: Cyanidin 3-O -\beta -d-glucoside (C3G) is included in anthocyanins, and expected to have a potency to scavenge active oxygen species in vivo. Rats were fed a diet containing C3G (2 g/kg diet) for 14 days, and then subjected to hepatic ischemia-reperfusion (I/R) as an oxidative stress model. I/R treatment elevated the liver thiobarbituric acid-reactive substance concentration and the serum activities of marker enzymes for liver injury, and lowered the liver reduced glutathione …concentration. Feeding C3G significantly suppressed these changes caused by hepatic I/R. These results indicate that C3G functions as a potent antioxidant in vivo under oxidative stress. To clarify the mechanism of action of C3G, we investigated the absorption and metabolism of C3G in rats. C3G appeared in the plasma immediately after the oral administration of C3G. Protocatechuic acid, which seems to be produced by the degradation of cyanidin, was also present in the plasma. In the liver and kidneys, C3G was metabolized to methylated form. Show more

Keywords: anthocyanin, cyanidin 3-O-\beta-d-glucoside, antioxidant, ischemia-reperfusion injury, metabolism

Citation: BioFactors, vol. 13, no. 1-4, pp. 133-139, 2000

Authors: Nobuji Nakatani,

Article Type: Research Article

Abstract: Spices and herbs are recognized as sources of natural antioxidants and thus play an important role in the chemoprevention of diseases resulting from lipid peroxidation. Our studies on spices and herbs have given us over a hundred compounds, known and new, having high antioxidant activity. From the Labiatae family, {\it Rosmarinus officinalis, Thymus vulgaris, Origanum vulgare} and {\it O. majorana} gave 26 active comopounds. Over 40 antioxidative compounds from {\it Zingiber officinale}, 26 compounds from {\it …Curcuma domestica = C. longa, C. xanthorrhiza} and {\it Z. cassumunar} were determined, these belonging to the family Zingiberaceae. From the family Myrtaceae, 25 compounds from the berries of {\it Pimenta dioica} were determined and 3 carbazoles were isolated from {\it Murraya koenigii}. Structure-activity relationships of some of the isolated compounds were also discussed. Show more

Citation: BioFactors, vol. 13, no. 1-4, pp. 141-146, 2000

Authors: Tsutomu Nakayama, | Toshihiko Hashimoto, | Katsuko Kajiya, | Shigenori Kumazawa,

Article Type: Research Article

Abstract: Interaction of tea catechins with lipid bilayers has been investigated with liposome systems. Epicatechin gallate had the highest affinity for lipid bilayers, followed by epigallocatechin gallate, epicatechin, and epigallocatechin. Epicatechin gallate and epigallocatechin gallate in the surface of lipid bilayer perturbed the membrane structure.

Keywords: catechins, polyphenols, EGCg, liposome, lipid bilayer

Citation: BioFactors, vol. 13, no. 1-4, pp. 147-151, 2000

Authors: Jen-Kun Lin, | Min-Hsiung Pan, | Shoei-Yn Lin-Shiau,

Article Type: Research Article

Abstract: Curcumin is a major component of Curcuma species, which is commonly used as a yellow coloring and flavoring agent in foods. Curcumin has shown anti-carcinogenic activity in animals as indicated by its ability to block colon tumor initiation by azoxymethane and skin tumor promotion induced by phorbol ester TPA. Curcumin possesses anti-inflammatory activity and is a potent inhibitor of reactive oxygen-generating enzymes such as lipoxygenase/cyclooxygenase, xanthine dehydrogenase/oxidase and inducible nitric oxide synthase. …Curcumin is also a potent inhibitor of protein kinase C, EGF-receptor tyrosine kinase and I\kappa B kinase. Subsequently, curcumin inhibits the activation of NF\kappa B and the expressions of c-jun, c-fos, c-myc and iNOS. It is proposed that curcumin may suppress tumor promotion through blocking signal transduction pathways in the target cells. Curcumin was first biotransformed to dihydrocurcumin and tetrahydrocurcumin and that these compounds subsequently were converted to monoglucuronide conjugates. These results suggest that curcumin-glucuronide, dihydro-curcumin-glucuronide, tetrahydrocurcumin-glucuronide and tetrahydrocurcumin are major metabolites of curcumin in mice. Show more

Keywords: curcumin, dihydrocurcumin, tetrahydrocurcumin, Curcumin-glucuronide, biotransformation

Citation: BioFactors, vol. 13, no. 1-4, pp. 153-158, 2000

Authors: Chi-Tang Ho, | Mingfu Wang, | Guor-Jien Wei, | Tzou-Chi Huang, | Mou-Tuan Huang,

Article Type: Research Article

Abstract: Rosemary and sage are common spices used in food. In our recent search of cancer chemopreventive agents from spices, the alcohol extracts of rosemary and sage showed strong antumorigenic activities. Rosemary and sage extracts contain active antioxidative factors such as phenolic diterpenes, flavonoids and phenolic acids. Here we discuss chromatographic methods used to separate and purify compounds from these spices and MS and NMR spectrometry to identify the isolated compounds. Several new compounds isolated from sage …were determined to be 6-O -caffeoyl-\beta -D-fructofuranosyl-(2 \rightarrow 1)-\beta -glucopyranoside, 1-O -caffeoyl-\beta -D-apiofuranosyl-(1 \rightarrow 6)-\beta -D-glucopyranoside, 1-O -p -hydroxybenzoyl-\beta -D-apiofuranosyl-(1 \rightarrow 6)-\beta -D-glucopyranoside, 1-O -(3-methyl-2,3,4-trihydroxybutyl)-6-O -feruloyl-\beta -D-glucopyranoside, 4-hydroxyacetophenone 4-O -[5-O -(3,5-dimethoxy-4-hydroxybenzoyl)-\beta -D-apiofrunosyl]-(1 \rightarrow 2)-\beta -D-glucopyranoside and 1-O -[2-hydroxy-5-(2-hydroxyethyl)phenyl]-6-O -trans-caffeoyl-\beta -D-glucopyranoside. Show more

Citation: BioFactors, vol. 13, no. 1-4, pp. 161-166, 2000

Authors: Koji Yamada, | Hirofumi Tachibana,

Article Type: Research Article

Abstract: Lipids and anti-oxidative factors regulate immune functions such as immunoglobulin production and chemical mediator release. For example, polyunsaturated fatty acids (PUFA) enhance IgE production of isolated rat lymphocytes, but not in the presence of \alpha -tocopherol. In addition, anti-oxidative factors such as tea polyphenols and flavonoids exert inhibitory effect on chemical mediator release from rat peritoneal exudate cells (PEC). Some of these immunoregulatory activities of food components could be expressed {\it …in vivo}. Oral administrations of perilla and fish oils or tea polyphenols led to a significant decrease of LTB_4 releasing activity of rat PEC, but IgE production enhancing activity of PUFA was not expressed in vivo. On the other hand, \alpha -tocopherol feeding enhanced serum IgA level as well as IgA productivity of mesenteric lymph node lymphocytes. These results suggest that dietary fats and antioxidants are effective for the alleviation of allergic symptom and activation of immune functions. Show more

Keywords: \alpha-Tocopherol, tea polyphenol, flavonoids, polyunsaturated fatty acid

Citation: BioFactors, vol. 13, no. 1-4, pp. 167-172, 2000

Authors: Kwang-Geun Lee, | Alyson Mitchell, | Takayuki Shibamoto,

Article Type: Research Article

Abstract: Natural leaves and flowers containing numerous aroma chemicals are widely used in aromatherapy since ancient times. In addition to their pleasant smells, aroma chemicals might have some beneficial health effects. Aroma extracts, isolated from coffee beans, soybeans, and mung beans by steam distillation under mild conditions (55^{\circ} C and 85 mm Hg) were examined for their antioxidative activities. The inhibitory effect of these extracts toward hexanal/hexanoic acid conversion was measured in the …testing solution over prolonged time periods. The inhibitory effects of these extracts toward malonaldehyde formation from lipids oxidized by Fenton's reagent were also measured. The antioxidative activity of these extracts, in particular coffee bean extract, was consistent with that of BHT or \alpha -tocopherol (vitamin E). Soybeans and mung beans extract contained maltol, which inhibits hexanal oxidation significantly. Eugenol, which is one of the major constituents of mung bean extract, exhibited potent antioxidative activity in an aldehyde/carboxylic acid assay. Antioxidants such as eugenol and maltol may play an important role in the pharmaceutical activities of natural plant extracts used for aromatherapy. Show more

Keywords: aroma chemicals, aromatherapy, antioxidants, natural essence

Citation: BioFactors, vol. 13, no. 1-4, pp. 173-178, 2000

Authors: Fereidoon Shahidi,

Article Type: Research Article

Abstract: The effect of dietary factors on health promotion and disease prevention has been an issue of interest since antiquity and has become a subject of renewed research activity in recent years. Many of the components involved are antioxidative in nature and include phenolic compounds. These phenolics exist in the free, esterified, glycosylated and polymeric forms. Scrutiny of the source materials, their subsequent extraction under optimized conditions and evaluation of activity, followed by fractionation and structure …elucidation of active components is generally necessary. Meals obtained from oilseeds, such as canola, mustard, flax, borage, and evening primrose, after oil extraction, contained a variety of antioxidative factors. The antioxidative effect of source materials, their extracts or fractions thereof, depended on the seed type, the content and chemical nature of their active components. Show more

Citation: BioFactors, vol. 13, no. 1-4, pp. 179-185, 2000

Authors: Ayako Kanazawa, | Tomohiro Sawa, | Takaaki Akaike, | Shigeru Morimura, | Kenji Kida, | Hiroshi Maeda,

Article Type: Research Article

Abstract: Lipid hydroperoxides (LOOH or oxidized oils) are known as unfavorable food components. Molecular details of the fate and mechanisms of LOOH to exert adverse effects in vivo are, however, little understood. In the present study, we demonstrated that LOOH generated alkylperoxyl radical (LOO^{\cdot } ) after reaction with various heme compounds such as myoglobin, cytochrome c , hemin, hematin, etc., but little formation of other radical species was noticed such as …L^{\cdot} or LO^{\cdot} . It was also shown that LOO^{\cdot } thus formed exhibits cytotoxicity and caused DNA damages including strand breakage and abasic site formation. This highly toxic LOO^{\cdot } is effectively scavenged by hot water extracts of vegetable (soup), flavonoids, polyphenols as well as tocopherols. Another important finding is that crude vegetable oils are rich in potent-LOO^{\cdot } scavenging activity, which exhibits potent anti-oxidant activity as well; whereas highly purified oils are scanty in such components and LOO^{\cdot } scavenging activity. These findings imply that a considerate processing in the refining of oils should be needed to retain such potent endogenous anti-oxidative radical scavenging-components. Show more

Citation: BioFactors, vol. 13, no. 1-4, pp. 187-193, 2000