By breeding and feeding salt to spontaneously hypertensive rats (SHR) continuously over a long period (until 60wk old), rats with systolic blood pressures (SBP) of over 270mmHg were prepared. It was studied whether or not supplying large amounts of vitamin C (200mg/rat/d) over this period might bring any beneficial effect to blood pressure. Moreover, physico-chemical studies were performed to measure the components and enzymes in the blood and urine at 53 and 60 wk-old, and biochemical studies on vitamin C were also carried out in this experiment. Male (14 rats: 7wk-old, 100-105g) and female (15 rats: 7 wk-old, 95-100g) SHR were divided into three groups and bred continuously for 53wk. The A group rats were given salt (2.5g/100g of diet), the B group rats were given salt and vitamin C (500mg/100mL of drinking water), and the C group rats were controls. The results showed almost the same tendencies between male and female rats. The body weights of the SHR in groups A and B were slightly lower than group C. The amount of food intake in groups A and B was almost the same as group C. The amount of water intake was, in the order from highest to lowest, group A, B and C. The SBP of group A rats exhibited the highest value among the three groups. The SBP of group B rats given vitamin C simulta-neously with the salt resulted in a low blood pressure level close to that of the controls (group C). Furthermore, the DBP (diastolic blood pressure) also reflected the antihyperten-sive effect of vitamin C as well. The heartbeat of the rats was highest in group A, and was comparable to the value in the rats receiving vitamin C simultaneously with salt. For the tests on occult blood and protein in the urine, group A rats showed strong positive reactions, whereas the group B and C rats had decreased results for both tests. The organ weights of the liver, stomach, spleen, adrenal gland and kidneys per 100g rat body weight were not different among the three groups. The values for the bilirubin content, and the enzyme activities of ALT and AST in the blood showed to be the highest in the male rats of group A. The values from the group B rats decreased near to the normal value like the control group. Vitamin C was found to decrease the blood pressure in SHR, and also to work effectively to protect liver and kidney functions even under the condition of very high blood pressure, as high as 250mmHg.

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The effect of a-tocopheryl succinate (TS) on protein kinase C (PKC) activity was examined. TS increased the auto-phosphorylation of PKC in vascular smooth muscle cells. Furthermore TS activated isolated PKC-like phorbol 12-myristate 13-acetate (PMA), although it was required at a significantly higher concentration than PMA for PKC activation. Molecular superimposition of the TS on PMA by computation suggested that TS took an active binding conformation to the PKC-like PMA, but that the conformational population was about 1/1 000. Consequently, we conclude that TS interacts directly with PKC, and activates it by taking an active conformation like PMA.

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L-Gulono-γ-lactone oxidase (GULO), which catalyzes the last step of ascorbic acid biosynthesis, is missing in humans. The whole structure of the human gene homologue for this enzyme was disclosed by a computer-assisted search. Only five exons, as compared to 12 exons constituting the functional rat GULO gene, remain in the human genome. A comparison of these exons with those of their functional counterparts in rat showed that there are two single nucleotide deletions, one triple nucleotide deletion, and one single nucleotide insertion in the human sequence. When compared in terms of colons, the human sequence has a deletion of a single amino acid, two stop colons, and two aberrant colons missing one nucleotide besides many amino acid substitutions. A comparison of the remaining human exon sequences with the corresponding sequences of the guinea pig nonfunctional GULO gene revealed that the same substitutions from rats to both species occurred at a large number of nucleotide positions. From analyses of the molecular evolution of Alu sequences in the human GULO gene homologue, it is thought that two Alu sequences were inserted in the vicinity of a presumed position of lost exon 11 during the same period as GULO lost its function. It is predicted that six LINE-1 sequences located in and near the gene homologue were inserted not during that period.

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In this study, we examined the effects of sesamin and vegetable oil on the concentrations of polyunsaturated fatty acid (PUPA) and lipids (triacylglycerol, free cholesterol, and phospholipid), and n-oxidation enzyme activities in the rat liver. Rats were fed a diet containing 5% (low-fat diet) or 20% (high-fat diet) salad oil (rapeseed oil: soybean oil, 7:3) with or without sesamin (0.5% w/w) for 4 wk. As a result, the concentrations of linoleic acid (LA, n-6), α-linolenic acid (ALA, n-3), and total PUPA in the liver increased significantly as the result of the high-fat diet. In the high-fat diet groups, sesamin administration decreased the concentrations of LA, ALA, and total PUPA to almost the same level as the low-fat diet group, while it increased the concentrations of dihomo-γ-linolenic acid (DGLA, n-6) and arachidonic acid (AA, n-6). The activities of carnitine acyltransferase and acyl-CoA dehydrogenase in liver mitochondria were enhanced by the intake of the high-fat diet, and were further enhanced by the administration of sesamin. Peroxisomal acyl-CoA oxidase activity was also enhanced by sesamin, while it was not affected by the dietary fat level. These results suggest that sesamin suppressed the increase of hepatic PUPA concentration caused by feeding the high-fat diet through enhancing the enzyme activities of fatty acid β-oxidation and PUPA metabolism from LA and ALA.

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The aims of this study were to evaluate the antioxidative effect of a traditional Taiwanese vegetable, Houttugnia cordata Thunb. (H, cordata), by subjecting rodents to oxidized frying oil-induced oxidative stress, and to examine the antimutagenic effects of H. cordata using the Ames test. Forty-eight Sprague-Dawley rats were fed a diet of 0, 2, or 5% H. cordata and 15% fresh oil or oxidized frying oil (OFO) for 28 d. Levels of polyphenol in the feces, plasma, and liver were determined. The LDL lag time, plasma total antioxidant status (TAS), and levels of thiobarbituric acid-reactive substances (TBARS) were used as antioxidative indices, and the protein carbonyl group was used as an oxidative index. The results showed that the polyphenol content decreased in the plasma and increased in the feces when administering OFO, and the apparent absorption of polyphenol also decreased. The polyphenol content in plasma increased when giving H. cordata. There was a higher polyphenol concentration in the water extracts of H. cordata than in the methanol extracts. The OFO-fed groups had higher plasma TBARS and hepatic protein carbonyl group concentrations and shorter LDL lag times than those of the control group. The total TAS was elevated and the LDL lag time was prolonged when fed with H. cordata. In addition, both water and methanol extracts of H. cordata had an antimutagenic effect on benzo(a)pyrene, aflatoxin B₁, and OFO, and showed a dose-dependent response using the Ames test. The antimutagenic ability of water extracts was higher than that of the methanol extracts. In conclusion, the polyphenol in H. cordata is easily absorbed and metabolized by rodents. H. cordata showed both antioxidative and antimutagenic properties under OFO feeding-induced oxidative stress.

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The antioxidant activities of Chlorella in vitro and in vivo were investigated. Chlorella showed a strong antioxidant effect compared to various vegetables in a 1, 1-diphe-nyl-2-picrylhydrazyl (DPPH) radical scavenging assay. To evaluate the antioxidant and anticataract effects in vivo, a 7.3% Chlorella powder was fed to rats with Streptozotocin-induced diabetes for 11 wk. At the end of the experiment, Chlorella had decreased the blood glycated hemoglobin (hemoglobin Ale) and serum cholesterol levels significantly, however, it had not affected the serum glucose concentration. The serum lipid peroxide value (TBARS value) in the rats fed Chlorella was lower than that of the control rats. In the liver and kidney, Chlorella also reduced chemiluminescent intensities. In addition, it delayed the development of lens opacities. The lens lipid peroxide content of the rats fed Chlorella was lower than that of the control rats, however the differences were not significant. These results indicate that Chlorella has antioxidant activity and may be beneficial for the prevention of diabetic complications such as cataracts.

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The oral administration of pectin to rats reduced and delayed the peak plasma triacylglycerol concentration. Pectin inhibited the hydrolysis of trioleoylglycerol emulsified with soybean phosphatidylcholine by pancreatic, carboxylester, and lingual lipases in a concentration-dependent manner. However, the effective concentration of pectin for lingual lipase was 100 times lower than that for pancreatic lipase. Pectin did not inhibit the tributyrin- and p-nitrophenylbutyrate-hydrolyzing activities by pancreatic and carboxylester lipase. When low molecular weight pectin was assayed, pectin at a molecular weight of 90, 000 (MW 90) most strongly inhibited three lipase activities. When the effect of pH on pectin inhibition was analyzed using pancreatic lipase, strong inhibition was observed at an acidic pH (below pH 7.0). In the assay system, the pancreatic lipase protein levels in the supernatant and fat layer were estimated by Western blotting with an anti-pancreatic lipase antibody. Pectin reduced the amount of pancreatic lipase protein in the fat layer in a concentration-dependent manner and concomitantly increased that in the supernatant. These results suggest that pectin may interact with emulsified substrates and inhibit the adsorption of lipase to the surface of substrate emulsion.

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It has been known that Hyssopus offlcinalis (hyssop) is a herb that grows in the wild and is a source of natural antioxidants. We previously reported that α-glucosidase inhibitors, (2S, 3S)1-O-β-D-6'-O-cinnamoylglucopyranosyl-3-(3'', 5''-dimethoxy-4''-hydroxy-phenyl)-1, 2, 3-propanetriol and (2S, 3S)1-O-β-D-glucopranosyl-3-(3'', 5''-dimethoxy-4 hydroxy-phenyl)-1, 2, 3-propanetriol, from the dry leaves of hyssop, were isolated. This study examined the α-glucosidase inhibitory effects of hyssop extracts on intestinal carbohydrate absorption in rat everted gut sac and carbohydrate-loaded hyperglycemia in mice. In the everted gut sac experiment, 10mM sucrose- and 5mM maltose-treated increases in glucose concentration in the serosal compartment were inhibited in the presence of 0.5 and 1.0mg/mL hyssop extracts, although a 10mM glucose-induced increase in serosal glucose was not inhibited by the extracts. Additionally, hyperglycemia in sucrose- and maltose-loaded mice was significantly suppressed at an early stage, within 30 to 60 min by oral pre-administration of 300 and 100mg/kg hyssop extracts, respectively. These findings suggest that hyssop extracts inhibited the digestion of complex carbohydrates, but not that of absorbable monosaccharide, and might be a useful supplemental food for hyperglycemia.

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This study was designed to determine if oral sodium Selenite supplementation to Se-depleted rat pups furnishes protection against hyperoxic lung injury. Twelve female rats were bred and fed a Se-deficient (0.04ppm Se) diet during pregnancy and lactation. Pups were supplemented either with 0 or 3.2 ng Se/g body weight daily from days 2 to 7. On day 4, two litters were mixed, with half of the pooled litter assigned to an air environment and the other half to an oxygen environment. Dams cross-fostered pups for 4 d. Selenite supplementation increased pup plasma and liver selenium concentration and the liver activity of glutathione peroxidase (GPx). However, lung GPx activity was more affected by oxygen exposure than Selenite supplementation. While oral Se supplementation of the pups showed a tendency for decreased incidence of lung injury with oxygen exposure, this apparent effect was not statistically significant. Selenium-supplemented pups also showed a trend toward larger internal surface area and lung volume than selenium-depleted pups. These data indicate that early postnatal selenium repletion via direct oral Selenite supplementation may be beneficial to rat pups against hyperoxic lung injury.

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Since kale (Brassica oleracea var, acephala), a cruciferous vegetable with a high level of vitamins and functional compounds beneficial to health and wellness, has become widely used in the juice industry, a precise method for quality control of vegetable species is necessary. We describe here a DNA-based identification method to distinguish kale from cabbage (Brassica oleracea var. capitata), a closely related species, which can be inadvertently mixed with kale during the manufacturing process. Using genomic DNA from these vegeta-bles and combinatory sets of nucleotide primers, we screened for random amplified polymorphic DNA (RAPD) fragments and found three cabbage-specific fragments. These RAPD fragments, with lengths of 1.4, 0.5, and 1.5kb, were purified, subcloned, and sequenced. Based on sequence-tagged sites (STS), we designed sets of primers to detect cabbage-specific identification (CAI) DNA markers. Utilizing the CAI markers, we successfully distinguished more than 10 different local cabbage accessions from 20 kale accessions, and identified kale juices experimentally spiked with different amounts of cabbage.

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