The effects of different high-fat (lard, soybean oil, corn oil or olive oil) diets supplemented with fructo-oligosaccharides on colonic alkaline phosphatase activity in rats.

PURPOSE: We recently reported that fermentable non-digestible carbohydrates including fructo-oligosaccharides (FOS) commonly elevate colonic alkaline phosphatase (ALP) activity and the expression of IAP-I, an ALP gene, in rats fed a high-fat (HF) diet, and also elevate gut mucins and modulate gut microbiota. This study aims to investigate whether dietary fat types influence the effect of FOS on colonic ALP activity and the luminal environment in HF-fed rats. METHODS: Male Sprague-Dawley rats were fed a diet containing 30% soybean oil, corn oil, olive oil or lard with or without 4% FOS for 2 weeks. Colon ALP activity, gene expression, and gut luminal variables including mucins and microbiota were measured. RESULTS: In the lard diet groups, dietary FOS significantly elevated colonic ALP activity and the expression of IAP-I. The elevating effect of FOS on colonic ALP activity was also observed in the olive oil diet groups, although here the IAP-I expression was not changed. However, the soybean oil and corn oil diet groups did not exhibit the elevating effect of FOS on colon ALP. Fecal ALP and mucins were significantly elevated by dietary FOS regardless of dietary fat types, and the effect of FOS was prominent in the lard diet groups. The number of Lactobacillus spp. observed in fecal matter was significantly increased by dietary FOS in the lard and olive oil diet groups, but not in the soybean oil and corn oil diets groups. CONCLUSION: This study suggests that dietary fat types may change the effect of FOS on the colonic luminal environment including the ALP activity in rats fed a high-fat diet.

Dietary inositol hexakisphosphate, but not myo-inositol, clearly improves hypercholesterolemia in rats fed casein-type amino acid mixtures and 1,1,1-trichloro-2,2-bis (p-chlorophenyl) ethane.

We have previously shown that dietary inositol hexakisphosphate (IP6) and myo-inositol prevent fatty liver in rats fed a casein-based diet containing 1,1,1-trichloro-2,2-bis (p-chlorophenyl) ethane (DDT). This study was performed to examine the comparative effects of dietary equimolar amounts of sodium IP6 (1.02%) and myo-inositol (0.2%) on the development of DDT-induced fatty liver and hypercholesterolemia in rats fed 20% casein-type amino acid mixtures designed to exclude a possible myo-inositol contaminant in casein. Thirty-six male Wistar rats were divided into 6 groups of 6 rats each for: a control group, myo-inositol-supplemented group, IP6-supplemented group, DDT-treated group, DDT + myo-inositol-supplemented group, and a DDT + IP6-supplemented group. Dietary IP6 clearly suppressed the rises in serum concentrations of cholesterol and phospholipids because of DDT feeding, but myo-inositol had no significant influence on such elevations. Dietary IP6, but not myo-inositol, caused significant body weight gain with or without DDT intake. Supplemental IP6 and myo-inositol significantly increased hepatic-free myo-inositol regardless of DDT intake and prevented fatty liver in rats fed DDT. In conclusion, dietary IP6 and myo-inositol exert similar effects on DDT-induced fatty liver and myo-inositol status but distinct effects on DDT-induced hypercholesterolemia and growth rate in rats fed casein-type amino acid mixtures.

Dietary lectin lowers serum cholesterol and raises fecal neutral sterols in cholesterol-fed rats.

This study examined the influence of a low level of dietary lectin (0.34%), at a dose that did not affect body weight or food intake, on the concentration of serum cholesterol and fecal excretion of neutral sterols in rats fed a diet containing 0.50% cholesterol and 0.13% sodium cholate for 12 d. In experiment 1, rats fed a diet with 0.34% lectin, concanavalin A, had significantly lower concentrations of serum total cholesterol and hepatic cholesterol, a higher ratio of HDL-cholesterol to total cholesterol, enhanced excretion of fecal neutral sterols and reduced apparent cholesterol absorption or digestibility as compared with rats fed a diet without lectin. Fecal excretion of acidic sterols was unaffected by dietary lectin. In contrast, dietary 0.34% lectin had no significant effect on concentrations of serum total protein or glucose. In experiment 2, we examined whether the cholesterol-lowering activity of the lectin was responsibility for its carbohydrate-binding activity. The effect of dietary lectin on concentrations of serum and hepatic cholesterol and excretion of fecal neutral sterols was prevented by simultaneous administration of methyl-alpha-D-mannopyranoside with specific affinity for the carbohydrate-binding sites of the lectin. These results suggest that dietary lectins might reduce concentrations of serum and hepatic cholesterol by a mechanism involving higher excretion of neutral sterols and that these alterations might be associated with the carbohydrate-binding activity of lectin.

Effect of dietary level of phytic acid on hepatic and serum lipid status in rats fed a high-sucrose diet.

The effect of dietary 0.02-10% sodium phytate on the hepatic and serum lipid status of rats fed a high-sucrose diet for 14 d was investigated. Hepatic levels of triglyceride and cholesterol and lipogenic enzymes activity were reduced with increasing dietary phytate level. The addition of 10% sodium phytate drastically depressed growth, food intake, and serum triglyceride and cholesterol levels.

Effects of dietary carbohydrate and myo-inositol on metabolic changes in rats fed 1,1,1-trichloro-2,2-bis (p-chlorophenyl) ethane (DDT).

This study was conducted to examine the effects of dietary carbohydrate [starch or sucrose (500 g/kg diet)] and myo-inositol (2 g/kg diet) on metabolic changes in rats fed 1,1,1-trichloro-2,2-bis (p-chlorophenyl) ethane (DDT) (0.7 g/kg diet). Dietary DDT enhanced serum and hepatic lipids and hepatic thiobarbituric acid reactive substances (TBA-RS), elevated hepatic activities of lipogenic enzymes such as malic enzyme (ME), glucose-6-phosphate dehydrogenase (G6PD) and fatty acid synthetase (FAS), increased hepatic cytochrome P-450 content and the activities of drug-metabolizing enzymes such as aminopyrine N-demethylase, glutathione S-transferase and 4-nitrophenol-UDP glucuronosyltransferase (4NP-UDPGT) and raised hepatic ascorbic acid and serum copper. Dietary sucrose promoted the increases in hepatic concentrations of total lipids, triglyceride and cholesterol, hepatic activity of ME, hepatic TBA-RS, cytochrome P-450 content and serum copper due to DDT feeding when compared to DDT administered in a starch based diet. Dietary myo-inositol significantly depressed the rises in hepatic concentrations of total lipids, triglyceride and cholesterol and the activities of ME and G6PD due to DDT feeding regardless of dietary carbohydrate quality. Dietary starch supplemented with myo-inositol potentiated the enhancements in hepatic activities of Phase II drug-metabolizing enzymes such as glutathione S-transferase and 4NP-UDPGT due to DDT feeding. These results suggest that dietary starch and myo-inositol can protect DDT fed rats against an accumulation of hepatic lipids, which might be mainly ascribed to the depression of hepatic lipogenesis. In addition, the present study implies that the supplementation of myo-inositol to high starch diet might improve the function of drug-metabolizing enzymes exposed to DDT.

Oxalic acid is available as a natural antioxidant in some systems.

Oxalic acid is found in a wide variety of plants. This study showed that oxalic acid suppressed in vitro lipid peroxidation in a concentration-dependent manner. Furthermore, oxalic acid reduced the rate of ascorbic acid oxidation in the presence of hydrogen peroxide and Cu(2+). These results suggest that oxalic acid is available as a natural antioxidant.