In the resent study, the effects of vitamins E and C on the levels of neuro- transmitters and acetylcholinesterase activity in the brains of rats treated with scopo-lamine, an inducer of dementia, were examined. Fifty male Sprague-Dawley rats at the age of 5 wk were divided into five groups after 1 wk of adaptation and fed five different diets for 6 wk: a no-scopolamine group, which was a scopolamine-untreated group fed only a basal diet; a scopolamine-treated group fed a basal diet; a vitamin E-supplemented scopolamine-treated group; a vitamin C-supplemented scopolamine-treated group; and a vitamins E and C-supplemented scopolamine-treated group. Scopolamine was twice administered by in-traperitoneal injection (300 mg/kg, body weight), 3 d and 20 min prior to sacrifice. Brain acetylcholinesterase activity was markedly reduced by scopolamine injection. However, the supplementation of vitamins E and C in the diet significantly increased the reduced brain acetylcholinesterase activity up to the level of the scopolamine-untreated group. Brain sero-tonin concentration in the vitamin C-supplemented scopolamine-treated group was signifi-cantly higher than that in the scopolamine-treated group. However, there were no signifi-cant differences in brain dopamine and norepinephrine concentrations among all groups. In, conclusion, supplementation with vitamin E and/or vitamin C might be useful in main-taining brain acetylcholinesterase activity at the normal level and serotonin concentration for some extent under the condition to induce dementia by scopolamine administration.

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This study investigated the effects of L-carnitine on insulin-like growth factor-I/II (IGF-I/II) and insulin-like growth factor binding proteins (IGFBPs) in streptozotocin (STZ)-induced diabetic rats. Each rat in the three L-carnitine-treated groups was injected subcutaneously with L-carnitine, 50 (D50), 100 (D100), or 200 (D200) mg/kg body weight every other day for four weeks, and animals in normal (N) and diabetic (DM) groups re-ceived saline by the same method. Diabetic rats had significantly lower carnitine concentra-tions in serum and liver compared with normal rats. Total carnitine concentrations were in-creased dose-dependently by carnitine treatment. Total IGF-I in serum from diabetic rats was increased dose-dependently by carnitine treatment, but was statistically significant only in the D200 group. The expression of liver IGF-I mRNA was lower in diabetic rats than in normal rats and increased by L-carnitine treatment. L-Carnitine treatment of diabetic rats had no effect on the levels of IGF-II in serum, liver, and kidney. Although the levels of IGF-II in serum and kidney of diabetic rats were increased in comparison with normal rats, IGF-II mRNA was not expressed in liver. Diabetic rats had markedly lower IGFBP-3 than normal rats did, and IGFBP-3 was increased by L-carnitine treatment. These results demonstrate that L-carnitine treatment of diabetic rats modulates the IGFs/IGFBPs axis. Especially note-worthy is that L-carnitine at a dose of 200 mg/kg/48 h for four weeks was able to restore serum total IGF-I in STZ-induced diabetic rats to nearly normal levels.

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The effect of dietary cyclodextrins on liver and serum lipids and cecal organic acid production was investigated. Male Wistar rats were fed a.basal diet and a diet contain-ing 5% of α-, β-, or γ-cyclodextrin. The body weight gain in rats fed the α-cyclodextrin diet was not significantly different from rats fed the other three kinds of diets. The feeding of di-etary α-cyclodextrin increased total lipid and phospholipids in the liver. β-Cyclodextrin sig-nificantly lowered serum total cholesterol and phospholipid levels compared with the basaldiet et al. A decrease in serum triacylglycerol levels was also observed in β-cyclodextrin-fed rats. Dietary α-cyclodextrin significantly increased the weight of cecal tissues and contents, and an approximate fourfold increase in acetate, propionate, and total organic acids was noted, indicating the fermentibility of β-cyclodextrin compared with the basal diet. It seems likely that the suppression of serum cholesterol levels by α- and, 3-cyclodextrins might be due to the increasing acetate and propionate productions in the cecum.

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The antidiabetic activity of Momordica charantia L. (Cucurbitaceae) was investigated in KK-Ay mice, an animal model with type 2 diabetes with hyperinsulinemia. The water extract of the fruit of Momordica charantia L. (MC) reduced the blood glucose of KK-Ay mice 3 weeks after oral administration (p<0.01) and also significantly lowered the serum insulin of KK-Ay mice under similar conditions (p<0.01). However, MC did not affect the blood glucose in normal mice. MC-treated KK-Ay mice blood glucose significantly decreased in an insulin tolerance test. Moreover, the muscle content of facilitative glucose transporter isoform 4 (GLUT4) protein content in the plasma membrane fraction from muscle significantly increased in the orally MC-treated mice when compared with that of the controls (p<0.01). These results suggest that the antidiabetic effect of MC is derived, at least in part, from a decrease in insulin resistance because of the increase of GLUT4 protein content in the plasma membrane of the muscle.

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The branched-chain a-ketoacid dehydrogenase (BCKDH) complex is the rate-limiting enzyme in the catabolism of branched-chain amino acids. In the present study, we examined the effects of exercise training on the activity and enzyme expression of the he-patic BCKDH complex in diabetic rats. The rats were prepared by intravenous injections of streptozotocin (50 mg/kg BWW), and exercise training was accomplished by treadmill run-ning for 45 min/d for 4 wk. The total and actual activities of hepatic BCKDH complex were significantly increased to 160% by 4 wk of diabetes. On the other hand, diabetic rats in the trained group had the same level of activities as those in the normal rats, indicating that ex-ercise training inhibited the diabetes-induced increase in the enzyme activities. The activity state (% active form) of the enzyme complex was about 100% in all groups and was not af-fected by diabetes or training. The protein amounts of the enzyme subunits (El a and E2) and the abundance of mRNA for the E2 subunit, but not for the other subunits, in the liver had the same trend as the activities. These results suggest that the capacity for branched-chain amino acid catabolism in streptozotocin-induced diabetic rats is reduced by exercise training and that this modification is associated with the suppression of diabetes-induced BCKDH complex expression in the liver.

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The aim of this study was to investigate the effect of probiotic, i.e., fermented milk prepared with Lactobacillus casei strain Shirota, on colonic motility by the strain gauge force transducer (SGFT) in a pig model. The contractions of the circular muscle layer of the cecum, upper colon, lower colon, and terminal colon in pigs were directly measured in conscious status by this method. This method was useful for quantitatively evaluating the effects of stimuli on colonic motility. Feeding significantly stimulated the motilities of the upper and lower colon. Defecation significantly stimulated the motilities of the upper and terminal colon. Two weeks' feeding of the fermented milk significantly activated the response to feeding in four portions of the large intestine. It increased motility of the terminal colon that did not promote defecation. The frequency of defecation from 9:00 to 10:00 (the period just after the morning meal) increased significantly, but from 0:00 to 1:00 (the midnight period) it decreased as a result of the ingestion of fermented milk. Such effects of the fermented milk on motility of the terminal colon are discussed in relation to the movement of digesta. The effects may relate to the stimulation of colonic fermentation as shown by a decrease in fecal pH.

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Flavonoids, a group of polyphenolic compounds, exist naturally and serve as antioxidants in vegetables, fruits, and so on. The inhibition of low density lipoprotein (LDL) oxidation may be an effective way to prevent or delay the progression of atherosclerosis. In the present study, we analyzed the radical scavenging capacity of 10 flavonoids (catechin, epicatechin [EC], epigallocatechin [EGC], epicatechin gallate [ECg], epigallocatechin gallate [EGCg], myricetin, quercetiji, apigenin, kaempferol, and luteolin) toward 1, 1-Biphenyl-2-picryl-hydrazyl [DPPH]. After 20 min of incubation, EGCg was the most effective DPPH radi-cal scavenger, luteolin being the least active of this flavonoid group. The mutual antioxidant effect of flavonoids with a-tocopherol (a-toc) on LDL oxidizability was investigated by using the lipophilic azo radical initiator 2, 2'-azobis(4-methoxy-2, 4-dimethylvaleronitrile) [AMVN-CH₃O]. An inhibitory effect of flavonoids on LDL oxidation was observed in the order of luteolin>ECg>EC>quercetin>catechin>EGCg>EGC>myricetin>kaempferol>apigenin. The shortened lag time induced by higher doses of a-toc (6 mg/100 mL) was re-stored by flavonoids. These results suggest that 1) radical trapping effects of flavonoids differ according to their structure, and 2) flavonoids act as hydrogen donors to a-toc radical; fur-thermore, by interaction with a-toc, they have a greater potential to delay the oxidation of LDL.

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In male C3H/He mice, which frequently develop spontaneous liver tumorige-nesis, 5 wk of age and weighing about 20 g, the comparative effects on liver tumor inci-dence from the feeding of olive oil (OLI), safflower oil (SAP), and linseed oil (US) diets for 50 wk, the concentrations of total cholesterol (T-CHOL), triacylglycerol (TG), lipid peroxides in the plasma and liver, and the activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the plasma were examined. The changes in body weight and liver weight were not different among dietary groups. The number of mice bearing liver ade-noma was greater in the SAP group than in the OLI and US groups. Liver carcinoma was observed in the SAP group, but not in the OLI and US groups. The concentrations of T-CHOL in the plasma and liver were higher in the OLI group than in the other groups. TG levels in the plasma and liver were highest in the OLI group and followed in order by the SAP and US groups. The concentration of plasma lipid peroxide was higher in the US group than in the other groups. Liver lipid peroxide content was extremely high in the US group, medium in the SAP group, and low in the OUT group. The activity of AST was highest in the OUT group and followed in order by the SAP and LIS groups. ALT activity was higher in the OUT group than in the other groups. A positive relationship between spontaneous liver tumorigenesis and the concentrations of T-CHOL, TG, and lipid peroxide or AST and ALT activities was hardly observed. These results suggested that spontaneous tumorigenesis in the liver of male C3H/He mice bred for 50 wk was suppressed by being supplied with OUT and LIS, compared with SAP, which had no direct relation to the concen-trations of T-CHOL, TG, and lipid peroxide in the plasma and liver and the activities of plasma AST and ALT.

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