Biofactors - Volume 13, issue 1-4

Authors: Hajime Ohigashi, | Toshihiko Osawa, | Junji Terao, | Shaw Watanabe, | Toshikazu Yoshikawa,

Article Type: Other

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

Authors: Harald Osmundsen, | Pierre Clouet,

Article Type: Research Article

Abstract: Some metabolic effects of dietary marine oils, or of dietary eicosapentaenoic or docosahexaenoic acid are reviewed. It is pointed out that docosahexaenoic acid appears more effective as regards induction of peroxisomal \beta -oxidation. Similarly, docosahexaenoic appears more powerful in terms of suppression of hepatic \Delta ^9 -desaturase activity and mRNA-levels. The potential inhibitory effect of polyunsaturated fatty acids, particularly docosahexaenoic acid, on mitochondrial \beta -oxidation is discussed. Experiments with …rats suggesting that the hypolipidaemic response of eicosapentaenoic acid is more marked when the fatty acid was given to fed rats, as compared to fasted rats, are discussed. Show more

Citation: BioFactors, vol. 13, no. 1-4, pp. 5-8, 2000

Authors: Takashi Ide,

Article Type: Research Article

Abstract: The activities of hepatic fatty acid oxidation enzymes in rats fed linseed and perilla oils rich in \alpha -linolenic acid (\alpha -18:3) were compared with those in the animals fed safflower oil rich in linoleic acid (18:2) and saturated fats (coconut or palm oil). Mitochondrial and peroxisomal palmitoyl-CoA (16:0-CoA) oxidation rates in the liver homogenates were significantly higher in rats fed linseed and perilla oils than in those fed saturated fats and safflower oil. …The fatty oxidation rates increased as dietary levels of \alpha -18:3 increased. Dietary \alpha -18:3 also increased the activity of fatty acid oxidation enzymes except for 3-hydroxyacyl-CoA dehydrogenase. Unexpectedly, dietary \alpha -18:3 caused great reduction in the activity of 3-hydroxyacyl-CoA dehydrogenase measured with short- and medium-chain substrates but not with long-chain substrate. Dietary \alpha -18:3 significantly increased the mRNA levels of hepatic fatty acid oxidation enzymes including carnitine palmitoyltransferase I and II, mitochondrial trifunctional protein, acyl-CoA oxidase, peroxisomal bifunctional protein, mitochondrial and peroxisomal 3-ketoacyl-CoA thiolases, 2, 4-dienoyl-CoA reductase and \Delta ^3 , \Delta ^2 -enoyl-CoA isomerase. Fish oil rich in very long-chain n -3 fatty acids caused similar changes in hepatic fatty acid oxidation. Regarding the substrate specificity of \beta -oxidation pathway, mitochondrial and peroxisomal \beta -oxidation rate of \alpha -18:3-CoA, relative to 16:0- and 18:2-CoAs, was higher irrespective of the substrate/albumin ratios in the assay mixture or dietary fat sources. The substrate specificity of carnitine palmitoyltransferase I appeared to be responsible for the differential mitochondrial oxidation rates of these acyl-CoA substrates. Dietary fats rich in \alpha -18:3-CoA relative to safflower oil did not affect the hepatic activity of fatty acid synthase and glucose 6-phosphate dehydrogenase. It was suggested that both substrate specificities and alterations in the activities of the enzymes in \beta -oxidation pathway play a significant role in the regulation of the serum lipid concentrations in rats fed \alpha -18:3. Show more

Keywords: \alpha-Linolenic acid, fatty acid oxidation enzyme, gene expression

Citation: BioFactors, vol. 13, no. 1-4, pp. 9-14, 2000

Authors: Morio Saito,

Article Type: Research Article

Abstract: Changes in susceptibility of tissues to lipid peroxidation were investigated in rats after ingestion of oxidation-prone docosahexaenoic acid (C_{22:6n-3} ). Lipid peroxide levels in the liver, kidney and testis increased concomitant with increases in the peroxidizability indices calculated from the fatty acid composition of tissue total lipids. However, even in these cases, the lipid peroxides were not increased to the levels expected from the peroxidizability indices of these tissues, and thus no tissue …injury was recognized. When low level of vitamin~E was given to rats, the lipid peroxide levels of liver, kidney and testis nearly coincided with the peroxidizability indices of these tissues, where the cell injuries were observed as well. The mechanisms of defense to suppress lipid peroxide levels below the peroxidizability indices in normal vitamin~E administration were presumed to be due to enhanced antioxidative function in the tissues mediated primarily by vitamin E, ascorbic acid and glutathione, and also to increased incorporation of docosahexaenoic acid into neutral lipids and phosphatidylethanolamine in the tissues, probably leading to acquiring stability against oxidative attack. Owing to these suppressive mechanisms, physiological efficacy of n-3 fatty acids may be exerted effectively. Show more

Keywords: docosahexaenoic acid, lipid peroxide, peroxidizability index, fatty acid composition, vitamin E, ascorbic acid, glutathione

Citation: BioFactors, vol. 13, no. 1-4, pp. 15-24, 2000

Authors: Katsumi Imaizumi, | Yosef Adan, | Kenichi Shibata,

Article Type: Research Article

Abstract: Effects of dietary fats include the development of arteriosclerosis in humans and experimental animals, in addition to hypercholesterolemia. None of the preceding studies explicitly compared the effects of individual fatty acids. To address these issues, we chose exogenously hypercholesterolemic (ExHC) rats and apolipoprotein (apo) E deficient mice as a model for atherosclerosis and assessed the individual role of fatty acids in animals' susceptibility to atherosclerosis. The rats fed on the diet containing DHA or …EPA, compared with those fed on the safflower oil (SO) diet, lowered serum cholesterol concentration, prevented platelet aggregation and slowed thickening in the ascending aorta. Apo E deficient mice developed hypercholesterolemia and severe lesion area in aortic root and arch, to a similar extent when they received DHA or SO. These results suggest a direct action of polyunsaturated fatty acids in the arterial wall, in addition to their effects on hypocholesterolemic and haemodynamic action. Show more

Keywords: atherosclerosis, eicosapentaenoic acid, docosahexaenoic acid

Citation: BioFactors, vol. 13, no. 1-4, pp. 25-28, 2000

Authors: Akira Tokumura, | Tuneki Sumida, | Masaoki Toujima, | Kentaro Kogure, | Kenji Fukuzawa,

Article Type: Research Article

Abstract: Lipid peroxidation is involved in the pathogenesis of chronic diseases including atherosclerosis. Oxidized lipoprotein has diverse biological activities and is believed to initiate atheroma formation and maturate fatty plaque. The active components of oxidized lipoproteins still remain to be clarified, but a likely candidate is the phosphatidylcholine (PC) having an {\it sn}-2-short-chain acyl group with a methyl, hydroxyl, aldehydic or carboxylic terminal. These unique PCs, formed by oxidative fragmentation of the polyunsaturated …acyl group of the parent PC in liposomes, low density lipoproteins and blood plasma, induce platelet aggregation through the activation of the receptor for platelet-activating factor (PAF), due to their resemblance in structure with PAF. We have found that PAF-like lipids regulate DNA synthesis and production of nitric oxide independently of the activation of the PAF receptor in vascular smooth muscle cells. Regulation of vascular cell function through two distinct signaling pathways mediated by PAF-like lipids provides new insight into the mechanism of induction of atherosclerosis. Show more

Keywords: platelet-activating factor, oxidized phosphatidylcholine, oxidized low density lipoprotein, atherosclerosis

Citation: BioFactors, vol. 13, no. 1-4, pp. 29-33, 2000

Authors: Sam J. Bhathena,

Article Type: Research Article

Abstract: Significant interactions exist between fatty acids and the endocrine system. Hormones affect the metabolism of fatty acids and the fatty acid composition of tissue lipids. The principal hormones involved in lipid metabolism are insulin, glucagon, catecholamines, cortisol and growth hormone. The concentrations of these hormones are altered in chronic degenerative conditions such as diabetes and cardiovascular disease, which in turn lead to alterations in tissue lipids. Lipogenesis and lipolysis, which modulate fatty …acid concentrations in plasma and tissues, are under hormonal control. Neuropeptides are involved in lipid metabolism in brain and other tissues. Polyunsaturated fatty acids (PUFA) are also precursors for eicosanoids including prostaglandins, leukotrienes, and thromboxanes, which have hormone-like activities. Fatty acids in turn alter both hormone and neuropeptide concentrations and their receptors. Saturated and trans fatty acids (TFA) decrease insulin concentration leading to insulin resistance. In contrast, PUFA increase plasma insulin concentration and decrease insulin resistance. In humans, omega-3 PUFA alter the levels of opioid peptides in plasma. Show more

Citation: BioFactors, vol. 13, no. 1-4, pp. 35-39, 2000

Authors: Tomohito Hamazaki, | Miho Itomura, | Shigeki Sawazaki, | Yoko Nagao,

Article Type: Research Article

Abstract: DHA is abundant in the brain. Deficiency of DHA changes behavior in animals. The purpose of the present studies was to clarify the effect of DHA intake on hostility and plasma catecholamines. In study 1, forty-one students took either DHA-rich oil capsules containing 1.5--1.8 g DHA/d (17 females and 5 males) or control oil capsules containing 97% males) for 3 mon in a double blind fashion. They took a psychological test (P-F Study) at the start and end …of the study. Study 1 started at the end of summer vacation and ended in the middle of mental stress of final exams. In the control group, hostility measured by P-F Study was significantly increased at the end of the study as compared with that measured at the start (+58 %) was not significantly changed in the DHA group (-14 %) double blind two-mon study (study 2), we measured plasma catecholamines and cortisol of students (3 females and 4 males for the DHA group and the same numbers for the control) at the start and end of the study. In study 2 the students were under a continuous stress of final exams that lasted for two mon throughout the whole study period. The plasma cortisol did not change in either group, but the norepinephrine concentration was significantly decreased in the DHA group (-31 %) group. These effects of DHA intake may be applied to people under psychological stress. Show more

Citation: BioFactors, vol. 13, no. 1-4, pp. 41-45, 2000

Authors: Kei Nakachi, | Satoru Matsuyama, | Satoshi Miyake, | Masami Suganuma, | Kazue Imai,

Article Type: Research Article

Abstract: The significance of drinking green tea in prevention of two of the main lifestyle-related diseases, cancer and cardiovascular disease, was demonstrated in terms of a prospective cohort study on a total of 8,552 general residents in Saitama Prefecture, Japan. On the basis of the follow-up study, we revealed decreased relative risk of cancer incidence for those consuming over 10 cups a day, compared with those consuming below 3 cups: 0.54 (95% men, 0.57 (0.34--0.98) for women, …and 0.59 (0.35--0.98) for both sexes. Furthermore, a significant delay in cancer onset was associated with increased consumption of green tea. Next, decreased relative risk of death from cardiovascular disease was 0.58 (0.34--0.99) for men, 0.82 (0.49--1.38) for women, and 0.72 (0.60--1.04) for members of both sexes consuming over 10 cups a day. Finally, we evaluated the life-prolonging effects of drinking green tea on cumulative survival, using the life table. Show more

Keywords: green tea, cancer, cardiovascular disease, prospective cohort study

Citation: BioFactors, vol. 13, no. 1-4, pp. 49-54, 2000

Authors: Teruo Miyazawa,

Article Type: Research Article

Abstract: Green tea is consumed as a popular beverage in Japan and throughout the world. During the past decade, epidemiological studies have shown that tea catechin intake is associated with lower risk of cardiovascular disease [1,2]. In vitro biochemical studies have reported that catechins, particularly epigallocatechin-3-gallate (EGCg), help to prevent oxidation of plasma low-density lipoprotein (LDL) [3,4,5]. LDL oxidation has been recognized to be an important step in the formation of atherosclerotic plaques and subsequent …cardiovascular disease [6]. Metabolic studies have shown that EGCg supplement is incorporated into human plasma at a maximum concentration of 4400 pmol/mL [7,8,9,10]. Such concentrations would be enough to exert antioxidative activity in the blood stream. The potent antioxidant property of tea catechin may be beneficial in preventing the oxidation of LDL. It is of interest to examine the effect of green tea catechin supplementation on antioxidant capacity of plasma in humans by measuring plasma phosphatidylcholine hydroperoxide (PCOOH) as a marker of oxidized lipoproteins. Show more

Citation: BioFactors, vol. 13, no. 1-4, pp. 55-59, 2000

Authors: Makoto Shimizu, | Yoko Kobayashi, | Miho Suzuki, | Hideo Satsu, | Yusei Miyamoto,

Article Type: Research Article

Abstract: Intestinal glucose uptake is mainly performed by its specific transporters, such as SGLT 1, GLUT 2 and 5 expressed in the intestinal epithelial cells. By using human intestinal epithelial Caco-2 cells we observed that intestinal glucose uptake was markedly inhibited by tea extracts. While several substances in green tea seem to be involved in this inhibition, catechins play the major role and epicatechin gallate (ECg) showed the highest inhibitory activity. Since our Caco-2 cells did not …express enough amount of SGLT 1, the most abundant intestinal glucose transporter, the effect of ECg on SGLT 1 was evaluated by using brush border membrane vesicles obtained from the rabbit small intestine. ECg inhibited SGLT 1 in a competitive manner, although ECg itself was not transported via the glucose transporters. These results suggest that tea catechins could play a role in controlling the dietary glucose uptake at the intestinal tract and possibly contribute to blood glucose homeostasis. Show more

Keywords: glucose transporters, catechins, intestinal cells, absorption

Citation: BioFactors, vol. 13, no. 1-4, pp. 61-65, 2000

Authors: Masami Suganuma, | Eisaburo Sueoka, | Naoko Sueoka, | Sachiko Okabe, | Hirota Fujiki,

Article Type: Research Article

Abstract: Among various biochemical and biological activities of tea polyphenols, we believe inhibition of the expression and release of tumor necrosis factor-\alpha (TNF-\alpha ) is crucial, since our study with TNF-\alpha -deficient mice has revealed that TNF-\alpha is an essential factor in tumor promotion. We found that EGCG dose-dependently inhibited AP-1 and NF-\kappa B activation in BALB/3T3 cells treated with okadaic acid, resulting in inhibition of …TNF-\alpha gene expression. Furthermore, treatment with 0.1% gene expression as well as TNF-\alpha protein level in the lung of TNF-\alpha transgenic mice; and IL-1\beta and IL-10 gene expression in the lung was also inhibited by treatment with green tea extract, indicating that green tea inhibits both TNF-\alpha and the cytokines induced by TNF-\alpha in organs. We recently found synergistic effects of EGCG and cancer preventive agents such as tamoxifen and sulindac, on cancer preventive activity. Taken together, the results show that green tea is efficacious as a non-toxic cancer preventive for humans. Show more

Keywords: EGCG, sulindac, tamoxifen, tumor promotion

Citation: BioFactors, vol. 13, no. 1-4, pp. 67-72, 2000

Authors: Chung S. Yang, | Jee Y. Chung, | Guang-yu Yang, | Chuan Li, | Xiaofeng Meng, | Mao-Jung Lee,

Article Type: Research Article

Abstract: Tea {\it (Camellia sinensis)} preparations have been shown to inhibit tumorigenesis at the initiation, promotion, and progression stages in different animal models. The anti-proliferative effects of tea polyphenols may be a key mechanism, especially in the NNK-induced lung tumorigenesis model with mice. Studies with cell lines have demonstrated that tea polyphenols inhibit cell proliferation and induce apoptosis. The effective concentrations used in these studies (20--100 \mu M) are usually higher than those …observed in blood and tissues of humans and animals, which are in the low micromolar range. Glucuronide and sulfate conjugated and methylated catechins as well as ring fission products (due to intestinal microflora) have been observed in human plasma and urine. Purified green and black tea polyphenols inhibited the H-{\it ras} induced mitogen-activated protein kinases, AP-1 activities, and the growth of 30.7b Ras 12 and BES21 cells. Among the catechins, both the galloyl structure on the B ring and the gallate moiety are important for the inhibition. Both (- )-epigallocatechin-3-gallate and theaflavin-3,3' -digallate inhibited the phosphorylation of c-jun and p44/42 (ERK 1/2). More mechanistic and human studies in these areas will help us to understand the possible inhibitory action of tea against carcinogenesis in humans. Abbreviations: EGCG, (- )-epigallocatechin-3-gallate; EGC, (- )-epigallocatechin; ECG, (- )-epicatechin-3-gallate; EC, (- )-epicatechin; NNK, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone; DGT, decaffeinated green tea; MAP kinase, mitogen activating protein kinase; AP-1, activator protein-1; NF\kappa B, nucleoprotein factor \kappa B. Show more

Citation: BioFactors, vol. 13, no. 1-4, pp. 73-79, 2000

Authors: Mamoru Isemura, | Kouichi Saeki, | Takashi Kimura, | Sumio Hayakawa, | Takeshi Minami, | Masaki Sazuka,

Article Type: Research Article

Abstract: Epigallocatechin gallate (EGCg) and theaflavins, a major constituent of green tea infusion and the constituents of black tea, respectively, were found to inhibit matrix metalloproteinases (MMPs) which are intimately associated with tumor invasion and metastasis. EGCg and related polyphenols exhibited apoptosis-inducing activity for several cancer cell lines including human stomach and colon cancer cells. Comparison of the activity of these compounds revealed the importance of the number and the steric disposition of …hydroxyl groups. A pyrogallol-type structure in a molecule is a minimum requirement for apoptosis induction of catechin compounds and that in the B ring has an important role in the activity. These data would provide useful information for designing anti-cancer agents on the basis of anti-inhibitory activity for MMPs and/or apoptosis-inducing activity. Show more

Keywords: epigallocatechin gallate, matrix metalloproteinase, apoptosis, tea polyphenol, anti-cancer agent

Citation: BioFactors, vol. 13, no. 1-4, pp. 81-85, 2000

Authors: Hoyoku Nishino, | Harukuni Tokuda, | Michiaki Murakoshi, | Yoshiko Satomi, | Mitsuharu Masuda, | Mari Onozuka, | Shino Yamaguchi, | Junko Takayasu, | Jun Tsuruta, | Masato Okuda, | Frederick Khachik, | Tomio Narisawa, | Nobuo Takasuka, | Masamichi Yano,

Article Type: Research Article

Abstract: Various natural carotenoids were proven to have anticarcinogenic activity. Epidemiological investigations have shown that cancer risk is inversely related to the consumption of green and yellow vegetables and fruits. Since \beta -carotene is present in abundance in these vegetables and fruits, it has been investigated extensively as possible cancer preventive agent. However, various carotenoids which co-exist with \beta -carotene in vegetables and fruits also have anti-carcinogenic activity. And some of …them, such as \alpha -carotene, showed higher potency than \beta -carotene to suppress experimental carcinogenesis. Thus, we have carried out more extensive studies on cancer preventive activities of natural carotenoids in foods; i.e., lutein, lycopene, zeaxanthin and \beta -cryptoxanthin. Analysis of the action mechanism of these natural carotenoids is now in progress, and some interesting results have already obtained; for example, \beta -cryptoxanthin was suggested to stimulate the expression of RB gene, an anti-oncogene, and p73 gene, which is known as one of the p53-related genes. Based on these results, multi-carotenoids (mixture of natural carotenoids) seems to be of interest to evaluate its usefulness for practice in human cancer prevention. Show more

Keywords: natural carotenoids, multi-carotenoids, cancer prevention

Citation: BioFactors, vol. 13, no. 1-4, pp. 89-94, 2000

Authors: Dae Joong Kim, | Nobuo Takasuka, | Hoyoku Nishino, | Hiroyuki Tsuda,

Article Type: Research Article

Abstract: An investigation was conducted to assess the chemopreventive potential of lycopene (LP), a naturally occurring hydrocarbon carotenoid found in tomatoes and their products, administered during the post-initiation stage in a multiorgan carcinogenesis model. One hundred eighteen B6C3F_1 mice of both sexes were subjected to combined treatment with diethylnitrosamine (DEN), N -methyl-N -nitrosourea (MNU) and 1,2-dimethylhydrazine (DMH) from day 11 after birth to week 9 (DMD treatment) …(groups 1 and 2) or given their vehicles (group 3). Then group 1 received LP (25 or 50 ppm in drinking water) for 21 weeks from weeks 11 to 32. Group 2 served as a carcinogen alone control and group 3 was given only LP (25 or 50 ppm). The incidences and multiplicities of lung adenomas plus carcinomas combined in male mice in group 1 receiving LP 50~ppm were significantly decreased as compared to the DMD alone or DMD and LP 25 ppm group values (75.0 vs 18.8%, While hepatocellular carcinomas were lacking in the DMD and LP groups, two cases were found in the DMD alone group (not statistically significant). The values for aberrant crypt foci (ACF) and tumors in the colon and kidney did not show any significant variation among the carcinogen-treated subgroups. The results of this study provide evidence that the tomato carotenoid, lycopene, may have potential as a chemopreventive agent against carcinogenesis in the male lung. Show more

Keywords: chemoprevention, lycopene (LP), mouse multiorgan carcinogenesis, lung cancer

Citation: BioFactors, vol. 13, no. 1-4, pp. 95-102, 2000

Authors: Teruo Kawada, | Yasutomi Kamei, | Atsushi Fujita, | Yoshifumi Hida, | Nobuyuki Takahashi, | Etsuro Sugimoto, | Tohru Fushiki,

Article Type: Research Article

Abstract: The adipocyte differentiation program is regulated by the sequential expression of transcriptional activators, mainly peroxisome proliferator activated receptor (PPAR) families. In the present study, we have decided to systematically examine the effects of vitamin A and its precursors, carotenoids and retinoids, on terminal differentiation from preadipocytes to adipocytes on the cellular and molecular aspects. The effects of active form of vitamin A, retinoic acid (RA), are believed to be mediated by specific nuclear receptor …proteins [retinoic acid receptor (RAR)] which are members of the steroid and thyroid/retinoid receptor superfamily of ligand dependent transcriptional regulators. RAR\alpha , RAR\gamma , RXR\alpha , and RXR\beta mRNA were abundant in adipose tissue and 3T3-L1 adipose cells. The autoregulated amplification of RAR\gamma mRNA was observed by these own ligands in 3T3-L1 cells. And, RA inhibited PPAR\gamma 2 expression more effectively and caused concomitantly a greater inhibition of adipocyte differentiation. These results suggest that the inhibitory action of adipocyte differentiation by carotenoids and retinoids are exhibited through the RAR up-regulation and the suppression of PPAR\gamma 2. The nature of the cross talk of vitamin A actions between the RARs, RXRs and PPARs via co-activator in adipose tissue will likely prove to be important for understanding the process of adipogenesis. Show more

Keywords: carotenoids, retinoids, vitamin A, nuclear receptor, adipocyte differentiation, fat soluble vitamin, peroxisome proliferator activated receptor

Citation: BioFactors, vol. 13, no. 1-4, pp. 103-109, 2000

Authors: Yoshifumi Tomita,

Article Type: Research Article

Citation: BioFactors, vol. 13, no. 1-4, pp. 111-112, 2000

Authors: Augustin Scalbert, | St\'ephanie D\'eprez, | Isabelle Mila, | Anne-Marie Albrecht, | Jean-Fran\c{c}ois Huneau, | Sylvie Rabot,

Article Type: Research Article

Abstract: Proanthocyanidins share common properties with other polyphenols, in particular their reducing capacity and ability to chelate metal ions. However, their polymeric nature clearly makes them different. They have a high affinity for proteins and their absorption through the gut barrier is likely limited to the molecules of low polymerization degree and to the metabolites formed by the colonic microflora, as suggested by {\it in vitro} experiments. The nutritional significance of proanthocyanidins is discussed in relation to …their physico-chemical properties and bioavailability. Show more

Keywords: proanthocyanidins, protein complexation, metal ion complexation, antioxidant capacity, bioavailability

Citation: BioFactors, vol. 13, no. 1-4, pp. 115-120, 2000

Authors: Takashi Yoshida, | Tsutomu Hatano, | Hideyuki Ito,

Article Type: Research Article

Abstract: Structure and function of polypehnols with high molecular weights (tannins) were briefly reviewed to better understand the significance of polyphenol-rich foods and beverages. In a survey of bioactive ellagiannins with a macrocyclic structure and/or a gluconic acid core, some new oligomeric ellagitannins (eucarpanins and elaeagnatins) have been found in species of Myrtaceae and Elaeagnaceae, and their structures were elucidated by spectroscopic and chemical methods. Cytotoxic activity against human oral tumor cell lines …and antibacterial activity against {\it Helicobacter pylori} have been evaluated for the ellagitannins obtained from both plants, and related compounds. The macrocyclic dimers, oentothein B, camelliin B and woodfordin C showed a remarkable cytotoxicity against human oral squamous cell carcinoma, but not against normal cells. These active tannins induced apoptosis of tumor cells. A potent antibacterial activity against {\it Helicobacter pylori} was exhibited by monomeric ellagitannins such as tellimagrandin I and stricitinin. Show more

Keywords: tannins, macrocyclic ellagitannin oligomers, ellagitannin with gluconic acid core, anti-{\it Helicobacter pylori} activity, cytotoxicity against human oral tumor cells

Citation: BioFactors, vol. 13, no. 1-4, pp. 121-125, 2000

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

Authors: Hirotomo Ochi, | Rong-Zhu Cheng, | Sachi Sri Kantha, | Masao Takeuchi, | Narasimhan Ramarathnam,

Article Type: Research Article

Abstract: It is widely accepted that oxidative stress (OS) is a major causative factor for many of the age-related dysfunctions and specific diseases. Since the oxidative stress state (OSS) of an individual depends on hereditary, dietary, and environmental factors, there is a large heterogeneity in the population that may be related to disease incidence and longevity. Hence there is a need to assess how well an individual is coping against OS. The Japan Institute for the Control …of Aging (JaICA) and Genox have jointly developed a profiling technique to measure the ``Oxidative Stress Profiles (JaICA-Genox OSP)'' of individuals and laboratory test animals. The JaICA-Genox OSP consists of about 45 different assays measuring the levels of oxidative damage in lipids and nucleic acids, and the antioxidant defenses in the serum. In addition, several bio-markers for cardiovascular disease risk are also measured, and assays to measure specific age- and sex-related hormones in the serum and urine, and race elements in serum, urine, and drinking water are also undertaken. This overview discusses the designing of the JaICA-Genox OSP and its application in the testing of human subjects. Show more

Keywords: oxidative stress, bio-markers, profiling technique, cardiovascular disease risk factors, age-related hormones, trace elements

Citation: BioFactors, vol. 13, no. 1-4, pp. 195-203, 2000

Authors: Claudine Berr,

Article Type: Research Article

Abstract: Cognitive impairment is a major component of age-related dementing diseases and it has been suggested that it could share the same pathological pathways with neurodegenerative processes and cerebrovascular lesions. The free radical theory of ageing could be one of these pathways. Implication of free radical damage in processes related to cerebral ageing is a good argument in favour of the hypothesis that antioxidants may protect against cognitive impairment. Observational studies (mostly cross-sectional) of relationships …between cognitive impairment and antioxidant status are based on the evaluation of dietary intake or on the levels of carotenoids, selenium and vitamins A, C and E in plasma or red blood cells. More convincing results were obtained on vitamin C and carotenoids. Despite some limitations, the comparison between results obtained in various populations is becoming increasingly informative and these studies argue for a protective effect of antioxidants on cognitive performance. Show more

Keywords: antioxidants, systemic markers, ageing, cognition, epidemiology

Citation: BioFactors, vol. 13, no. 1-4, pp. 205-209, 2000

Authors: Takuji Tanaka, | Hiroyuki Kohno, | Yoshiaki Tsukio, | Shiro Honjo, | Mikio Tanino, | Masaki Miyake, | Keiji Wada,

Article Type: Research Article

Abstract: Obacunone and limonin are bitter limonoids in citrus. Their modifying effects on the development of aberrant crypt foci (ACF), the activity of detoxification enzymes, glutathione S -transferase (GST) and quinone reductase (QR), and cell proliferation activity were investigated in male F344 rats treated with azoxymethane (AOM). Obacunone and limonin were administered in the diet, during the initiation (for 4 weeks) or postinitiation phase (for 4 weeks) of AOM-induced tumorigenesis. Feeding of obacunone and …limonin (0.02% 0.05%) and 28-42% ability to reduce the proliferating cell nuclear antigen-labeling index in crypts and correlated well with the prevention of ACF. In a subsequent long-term experiment (38 weeks), in which rats were initiated with AOM and fed 0.05% the initiation or post-initiation phase, both compounds in diet caused significant reduction (65%- colonic adenocarcinoma. Thus, citrus bitter limonoids obacunone and limonin possess chemopreventive effects on chemically induced rat colon carcinogenesis. Show more

Keywords: limonoids, obacunone, limonin, inhibition, colon carcinogenesis, rats

Citation: BioFactors, vol. 13, no. 1-4, pp. 213-218, 2000

Authors: Kazuyoshi Okubo, | Yumiko Yoshiki,

Article Type: Research Article

Abstract: We propose that the reactive oxygen species/hydrogen donor/mediator system (XYZ system) is a new chemiluminescence system for the measurement of reactive oxygen scavenging activity. By using this method, we demonstrated the role of triterpenoid on a reactive oxygen scavenging system. DDMP (2,3-dihydro-2,5-dihydroxy-6-methyl-4H -pyran-4-one) conjugated saponin from soybean, produced a low level light emission in the presence of H_2 O_2 (X) and gallic acid (Y). The soybean saponin acted …as a mediator (Z) on the reactive oxygen scavenging system. When comparing the data of photon emission properties of saponin with that of cholic acids, it concludes that DDMP moiety of soybean saponin plays an important role rather than the aglycon moiety in the radical scavenging system. Show more

Keywords: chemiluminescence, soybean, saponin, triterpenoid

Citation: BioFactors, vol. 13, no. 1-4, pp. 219-223, 2000

Authors: Mou-Tuan Huang, | Vladimir Badmaev, | Yu Ding, | Yue Liu, | Jian-Guo Xie, | Chi-Tang Ho,

Article Type: Research Article

Abstract: Boswellin (BE), a methanol extract of the gum resin exudate of {\it Boswellia serrata}, contains naturally occurring triterpenoids, \beta -boswellic acid and its structural related derivatives, has been used as a traditional medicine for the treatment of inflammatory and arthritic diseases. Topical application of BE to the backs of mice markedly inhibited 12-O -tetradecanoylphorbol-13-acetate (TPA)-induced increases in skin inflammation, epidermal proliferation, the number of epidermal cell layers, and tumor promotion …in 7,12-dimethylbenz[a]anthracene (DMBA)-initiated mice. Feeding 0.2% BE in the diet to CF-1 mice for 10--24 weeks reduced the accumulation of parametrial fat pad weight under the abdomen, and inhibited azoxymethane (AOM)-induced formation of aberrant crypt foci (ACF) by 46%. acid, 11-keto-\beta -boswellic acid or 3-O -acetyl-11-keto-\beta -boswellic acid (Fig. 1) to human leukemia HL-60 cell culture inhibited DNA synthesis in HL-60 cells in a dose-dependent manner with IC_{50} values ranging from 0.6 to 7.1 \mu M. These results indicate that \beta -boswellic acid and its derivatives (the major constituents of Boswellin) have anti-carcinogenic, anti-tumor, and anti-hyperlipidemic activities. Show more

Keywords: boswellin, triterpenoid, triterpene acid, boswellic acid, cancer prevention

Citation: BioFactors, vol. 13, no. 1-4, pp. 225-230, 2000

Authors: Masayuki Yoshikawa, | Hisashi Matsuda,

Article Type: Research Article

Abstract: Oleanolic acid glycosides from several medicinal foodstuffs were found to show potent inhibitory activity on the increase of serum glucose levels in oral glucose-loaded rats. By examination of the structure-activity relationships, the 3-O-glucuronide moiety and the 28-carboxyl group in oleanolic acid glycosides were required to exert the hypoglycemic activity. Oleanolic acid glycosides were found to have neither insulin-like nor insulin-releasing activity, but they inhibited gastric emptying and glucose-uptake in the small intestine. …Investigation of the mode of action revealed that the inhibition of gastric emptying was mediated by capsaicin-sensitive sensory nerves and the central nervous system. Furthermore, oleanolic acid glycosides were suggested to suppress the gastric emptying by stimulating the release and/or production of dopamine to act through dopamine_2 receptors, which in turn causes the release of prostaglandins. Show more

Citation: BioFactors, vol. 13, no. 1-4, pp. 231-237, 2000

Authors: Robert. T. Rosen, | Richard D. Hiserodt, | Elaine K. Fukuda, | Reginald J. Ruiz, | Zhengyi Zhou, | Joseph Lech, | Sharon L. Rosen, | Thomas G. Hartman,

Article Type: Research Article

Abstract: Gas Chromatography--Mass Spectrometry (GC- MS) was the major technique used to determine various metabolites after consumption of dehydrated granular garlic and an enteric-coated garlic preparation, in breath, plasma, and simulated gastric fluids. A special short-path thermal desorption device [1] was used as an introduction technique for the gas chromatograph for the determination of volatiles. These garlic preparations release allicin, which decomposes in stomach acid or with time in the intestine to release allyl …sulfides, disulfides and other volatiles, some of which are postulated to be metabolized by glutathione and/or S-adenosylmethionine to form allyl methyl sulfide, the main sulfur containing volatile metabolite. S-Allylcysteine, a non-volatile bioactive component of aged garlic preparations, was determined in human plasma and urine by HPLC-MS using the negative ion atmospheric pressure chemical ionization mode (APcI)- MS. The technique of selected ion monitoring was used for quantitation. A synthetic internal standard of deuterated S-allylcysteine was added to the plasma or urine to ensure recovery and to obtain reliable quantitative data. Show more

Keywords: allicin, S-allylcysteine, liquid chromatography, mass spectrometry, garlic metabolites

Citation: BioFactors, vol. 13, no. 1-4, pp. 241-249, 2000

Authors: Toyohiko Ariga, | Kentaro Tsuji, | Taiichiro Seki, | Tadaaki Moritomo, | Jun-ichiro Yamamoto,

Article Type: Research Article

Abstract: The antiplatelet activity of methyl allyltrisulfide (MATS), a component commonly present in steam-distilled garlic oil, has been demonstrated by the authors. MATS inhibits arachidonic acid cascade at the reaction site with PGH synthase. However, this enzyme catalyzes two successive reactions, from arachidonic acid to PGG_2 , and from PGG_2 to PGH_2 . The present study revealed that MATS inhibited the latter reaction. In addition, our recent findings that …to a promyelocytic leukemia cell HL60, Allium oils shows marked anti-neoplastic effects representing both growth suppression and differentiation activities are described. The garlic oil and onion oil showed almost equal ability in inducing the proliferation, which measured either by nitroblue-tetrazolium reducing activity assay or by flow cytometry for detecting CD11b expression. The combination use of one of these oils with all-trans retinoic acid or with dimethyl sulfoxide lead to the marked differentiation of the cells, and their effects were estimated to be synergistic. Show more

Keywords: sulfide compounds, allyl methyl trisulfide, arachidonic acid cascade, cell differentiation, garlic oil

Citation: BioFactors, vol. 13, no. 1-4, pp. 251-255, 2000

Authors: Hiroyuki Nishimura, | Tomonari Takahashi, | C. Hanny Wijaya, | Atsushi Satoh, | Toyohiko Ariga,

Article Type: Research Article

Abstract: Sulfur compounds contributed to the health promotion in {\it Allium} species are produced via enzymic and thermal reactions. Potent antithrombotic agents which have been identified as allyl trisulfides, dithiins, and ajoene in garlic ({\it A. sativum}) and caucas ({\it A. victorialis}) are thermochemically transformed from allicin (allyl 2-propenethiosulfinate). The leaves and stems of Japanese domestic {\it Allium} plant, {\it A. victorialis} L. which is widely distributed in the northern part of Japan, under the name …``Gyoja-ninniku'' is a nutritious vegetable. The significant flavor compounds of caucas are methyl allyl disulfide (Chinese chive odor), diallyl disulfide (garlic-like odor), and dimethyl disulfide and methyl allyl trisulfide (pickles-like odor) among more than 85 peaks on the gas chromatogram. 2-Vinyl-4H -1,3-dithiin and 3,4-dihydro-3-vinyl-1,2-dithiin as platelet aggregation inhibitors were found eliminated in dichloromethane extract of caucas. The significant health promoting factors, allyl trisulfides and dithiins were relatively increased when caucas was cooked on a frying pan. Show more

Keywords: Allium victorialis, disulfides, trisulfides, vinyldithiins, antithrombotic activity, radical scavenger

Citation: BioFactors, vol. 13, no. 1-4, pp. 257-263, 2000

Authors: Naohide Kinae, | Hideki Masuda, | Il Shik Shin, | Michiyo Furugori, | Kayoko Shimoi,

Article Type: Research Article

Abstract: Wasabi ({\it Wasabi japonica}) and horseradish ({\it Cholearia armoracia}) are used as spices of daily foodstuffs. Allylisothiocyanate (AIT) is a potent component in both plants and occurs by grating them. It is well known that AIT shows inhibitory effect on the growth of food poisoning bacteria and fungi. In this work, several functional properties of roots and leaves from wasabi and horseradish were examined in vitro. Each sample showed peroxidase activity. They also exhibited antioxidative and …superoxide scavenging potency. Antimutagenic activity was observed toward 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline [MeIQx], a well-known mutagen/carcinogen in broiled fish and meat. They also decreased His^+ revertant colonies of 3-chloro-4-dichloromethyl-5-hydroxy-2(5H )-furanone (MX) in the Ames test, a strong mutagen and carcinogen in chlorine disinfected tap water. Isolation of antimutagenic components in wasabi root was done. Three components including (- )-(R)-7-methylsulfinylheptyl isothiocyanate were identified. These data show that wasabi and horseradish might be potent functional foods for keeping human health. Show more

Keywords: wasabi, horseradish, antioxidative activity, radical scavenging potency, antimutagenic activity

Citation: BioFactors, vol. 13, no. 1-4, pp. 265-269, 2000

Authors: Yasujiro Morimitsu, | Kazuhiro Hayashi, | Yoko Nakagawa, | Fumihiko Horio, | Koji Uchida, | Toshihiko Osawa,

Article Type: Research Article

Abstract: 6-Methylsulfinylhexyl isothiocyanate (MS-ITC) was isolated from wasabi ({\it Wasabia japonica}, Japanese domestic horseradish) as a potential inhibitor of human platelet aggregation {\it in vitro} through our extensive screening of vegetables and fruits. In the course of another screening for the induction of glutathione S -transferase (GST) activity in RL34 cells, MS-ITC was inadvertently isolated from wasabi as a potential inducer of GST. MS-ITC administered to rats or mice also showed both activities …{\it in vivo}. As a result from elucidation of the platelet aggregation inhibition and the GST induction mechanisms of MS-ITC, the isothiocyanate moiety of MS-ITC plays an important role for antiplatelet and anticancer activities because of its highly reactivity with sulfhydryl (-SH) groups in biomolecules (GSH, cysteine residue in a certain protein, etc.). Show more

Keywords: isothiocyanate, platelet aggregation, phase II enzyme, glutathione s-transferase, cancer chemoprevention

Citation: BioFactors, vol. 13, no. 1-4, pp. 271-276, 2000

Authors: N. Yoshida, | H. Manabe, | Y. Terasawa, | H. Nishimura, | F. Enjo, | H. Nishino, | T. Yoshikawa,

Article Type: Research Article

Abstract: Leukocyte-endothelial cell interactions, which are mediated by various adhesion molecules, are a crucial event in inflammatory reactions including atherosclerosis. \alpha -Tocopherol (\alpha -Toc) has been used for protection and therapy of vascular diseases because of its antioxidant activity. The objective of the present study was to determine effect of \alpha -Toc on endothelial-dependent adhesive interactions with leukocytes elicited by oxidized low density lipoprotein (oxLDL). Incubation of HUVEC with oxLDL …(100 \mu g/mL) increased expression of proteins and messenger RNA of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) on enzyme immunoassay and northern blotting assay; pretreatment with \alpha -Toc reduced in a dose dependent manner. Adherence of polymorphonuclear leukocytes (PMN) or mononuclear leukocytes (MNC) to oxLDL-activated HUVEC was much increased compared with that to unstimulated HUVEC. Treatment of HUVEC with \alpha -Toc, monoclonal antibody to ICAM-1 or VCAM-1 inhibited adherence of PMN or MNC in a dose dependent manner. These results suggest that \alpha -Toc works as anti-atherogenic agent through inhibiting endothelial-dependent adhesive interactions with leukocytes induced by oxLDL. Show more

Keywords: \alpha-Tocopherol, adhesion molecules, leukocytes, endothelial cells

Citation: BioFactors, vol. 13, no. 1-4, pp. 279-288, 2000