Effects of dietary myo-inositol or phytic acid on hepatic concentrations of lipids and hepatic activities of lipogenic enzymes in rats fed on corn starch or sucrose

Cellular and Molecular Activities of IP6 in Disease Prevention and Therapy

IP6 (phytic acid) is a naturally occurring compound in plant seeds and grains. It is a poly-phosphorylated inositol derivative that has been shown to exhibit many biological activities that accrue benefits in health and diseases (cancer, diabetes, renal lithiasis, cardiovascular diseases, etc.). IP6 has been shown to have several cellular and molecular activities associated with its potential role in disease prevention. These activities include anti-oxidant properties, chelation of metal ions, inhibition of inflammation, modulation of cell signaling pathways, and modulation of the activities of enzymes and hormones that are involved in carbohydrate and lipid metabolism. Studies have shown that IP6 has anti-oxidant properties and can scavenge free radicals known to cause cellular damage and contribute to the development of chronic diseases such as cancers and cardiovascular diseases, as well as diabetes mellitus. It has also been shown to possess anti-inflammatory properties that may modulate immune responses geared towards the prevention of inflammatory conditions. Moreover, IP6 exhibits anti-cancer properties through the induction of cell cycle arrest, promoting apoptosis and inhibiting cancer cell growth. Additionally, it has been shown to have anti-mutagenic properties, which reduce the risk of malignancies by preventing DNA damage and mutations. IP6 has also been reported to have a potential role in bone health. It inhibits bone resorption and promotes bone formation, which may help in the prevention of bone diseases such as osteoporosis. Overall, IP6's cellular and molecular activities make it a promising candidate for disease prevention. As reported in many studies, its anti-inflammatory, anti-oxidant, and anti-cancer properties support its inclusion as a dietary supplement that may protect against the development of chronic diseases. However, further studies are needed to understand the mechanisms of action of this dynamic molecule and its derivatives and determine the optimal doses and appropriate delivery methods for effective therapeutic use.

Effects of nonantibiotic growth promoter combinations on growth performance, nutrient utilization, digestive enzymes, intestinal morphology, and cecal microflora of broilers

Given the ban on antibiotic growth promoters, the effects of nonantibiotic alternative growth promoter combinations (NAGPCs) on the growth performance, nutrient utilization, digestive enzyme activity, intestinal morphology, and cecal microflora of broilers were evaluated. All birds were fed pellets of two basal diets-starter (0-21 d) and grower (22-42 d)-with either enramycin (ENR) or NAGPC supplemented. 1) control + ENR; 2) control diet (CON, basal diet); 3) control + mannose oligosaccharide (MOS) + mannanase (MAN) + sodium butyrate (SB) (MMS); 4) control + MOS + MAN + Bacillus subtilis (BS) (MMB); 5) control + MOS + fruit oligosaccharide (FOS) + SB (MFS); 6) control + FOS + BS (MFB); 7) control + MOS + FOS + MAN (MFM); 8) control + MOS + BS + phytase (PT) (MBP). ENR, MOS, FOS, SB, MAN, PT, and BS were added at 100, 2,000, 9,000, 1,500, 300, 37, and 500 mg/kg, respectively. The experiment used a completely random block design with six replicates per group: 2400 Ross 308 broilers in the starter phase and 768 in the grower phase. All NAGPCs significantly improved body weight gain (P < 0.01), utilization of dry matter, organic matter, and crude protein (P < 0.05), villus height and villus height/crypt depth in the jejunum and ileum (P < 0.01), and decreased the feed conversion ratio (P < 0.01) at d 21 and 42. MMS, MMB, MFB, and MFM duodenum trypsin, lipase, and amylase activities increased significantly (P < 0.05) at d 21 and 42. On d 21 and 42, MMS, MMB, and MBP increased the abundance of Firmicutes and Bacteroides whereas MMB, MFB, and MBP decreased the abundance of Proteobacteria, compared to ENR and CON. Overall, the NAGPCs were found to have some beneficial effects and may be used as effective antibiotic replacements in broilers.

Sex-Specific Effects of Myo-Inositol Ingested During Lactation in the Improvement of Metabolic Health in Adult Rats

SCOPE

To examine the effects of myo-inositol supplementation during lactation in male and female rats on metabolic parameters and its potential to reverse metabolic alterations associated with a moderate gestational calorie restriction.

METHODS AND RESULTS

The offspring of control and 25% gestational calorie-restricted rats are supplemented with myo-inositol or vehicle throughout lactation and exposed to a Western diet (WD) from 5 to 7 months of age. Blood parameters are measured and gene expression and protein levels in retroperitoneal white adipose tissue (rWAT) and liver are analyzed. In male offspring, but not in females, myo-inositol supplementation resulted in lower fasting triglyceride and insulin levels and HOMA-IR at 7 months, and reversed the alterations in these parameters due to gestational calorie restriction. The expression pattern of key genes in metabolism in rWAT and liver support the beneficial effect of myo-inositol supplementation in reversing metabolic alterations programmed by gestational calorie restriction in male rats.

CONCLUSIONS

Myo-inositol supplementation at physiological doses during lactation improves metabolic health and prevents the programmed trend to develop insulin resistance and hypertriglyceridemia in male rats acquired by inadequate fetal nutrition and exacerbated by a diabetogenic diet in adulthood. The absence of clear effects in females deserves further investigation.

Effects of Dietary Supplementation with Myo-inositol on Hepatic Expression of Glycolytic and Fructolytic Enzyme Genes in Rats Fed a High-sucrose Diet

We examined effects of a major lipotrope, myo-inositol, on the expression of primary glycolytic (glucokinase and phosphofructokinase) and fructolytic enzyme (ketohexokinase [KHK] and aldolase B) genes in the livers of rats fed a control diet, high-sucrose diet, or high-sucrose diet supplemented with 0.5% myo-inositol for 14 d. Supplementation with myo-inositol decreased the hepatic expression of fructolytic enzyme genes, but not that of glycolytic enzyme genes, and the levels of triglycerides, fatty acid synthase, and KHK proteins in high-sucrose diet-induced fatty liver. The study results suggest that myo-inositol represses primary fructlysis, but not glycolysis, in high-sucrose diet-induced fatty liver.

Myo-inositol improves growth performance and regulates lipid metabolism of juvenile Chinese mitten crab (Eriocheir sinensis) fed different percentage of lipid

This study evaluated the effects of dietary myo-inositol (MI) on growth performance, antioxidant status and lipid metabolism of juvenile Chinese mitten crab (Eriocheir sinensis) fed different percentage of lipid. Crabs (4·58 (sem 0·05) g) were fed four diets including a normal lipid diet (N, containing 7 % lipid and 0 mg/kg MI), N with MI supplementation (N + MI, containing 7 % lipid and 1600 mg/kg MI), a high lipid diet (H, containing 13 % lipid and 0 mg/kg MI) and H with MI supplementation (H + MI, containing 13 % lipid and 1600 mg/kg MI) for 8 weeks. The H + MI group showed higher weight gain and specific growth rate than those in the H group. The dietary MI could improve the lipid accumulations in the whole body, hepatopancreas and muscle as a result of feeding on the high dietary lipid (13 %) in crabs. Besides, the crabs fed the H + MI diets increased the activities of antioxidant enzymes but reduced the malondialdehyde content in hepatopancreas compared with those fed the H diets. Moreover, dietary MI enhanced the expression of genes involved in lipid oxidation and exportation, yet reduced lipid absorption and synthesis genes expression in the hepatopancreas of crabs fed the H diet, which might be related to the activation of inositol 1,4,5-trisphosphate receptor (IP3R)/calmodulin-dependent protein kinase kinase-β (CaMKKβ)/adenosine 5'-monophosphate-activated protein kinase (AMPK) signalling pathway. This study demonstrates that MI could increase lipid utilisation and reduce lipid deposition in the hepatopancreas of E. sinensis fed a high lipid diet through IP3R/CaMKKβ/AMPK activation. This work provides new insights into the function of MI in the diet of crustaceans.

Molar ratios of dietary phytate to minerals and iron status of female residential students in University of Dhaka, Bangladesh

BACKGROUND

Female undergraduate students may undergo many health implications due to the transition from secondary to undergraduate level.

AIM

The study was aimed to assess molar ratios of phytate to minerals (calcium, zinc, and iron) in the diets, and to measure the iron status of resident female students at Dhaka University.

METHODS

In total, 180 female students between 18-26 years of age from 3 dormitories of Dhaka University were selected for the study. Dietary intake information was collected over three consecutive days. Multiple-Pass 24-hour recall. Blood hemoglobin and serum ferritin levels were analyzed for sub-sample (20 participants from each dormitory).

RESULTS

The mean dietary intake of phytate, calcium, zinc, and iron were estimated at 347.11, 181.04, 6.59, and 7.14 mg/day, and hemoglobin and serum ferritin at 11.34 g/dl, and 18.48 ng/ml, respectively. The respective molar ratios of phytate: calcium, phytate: zinc, phytate: iron and phytate × calcium: zinc were 0.13, 5.27, 4.20, and 21.26 in the diet of the respondents. The prevalence of anemia, iron deficiency and iron deficiency anemia among the respondents was found to be 51.7%, 48.4%, and 28.3%, respectively. Linear regression analysis showed that only zinc intake had positive association with hemoglobin, while iron and zinc intake had a significant positive, and phytate:iron molar ratio had a significant negative association with serum ferritin concentration (p < 0.05). After adjusting all significant determinants of serum ferritin, no predictors have found significant.

CONCLUSIONS

Larger and more specific research is needed to clearly understand the mechanism behind anemia and iron deficiency among female residential students.

Inositol and Non-Alcoholic Fatty Liver Disease: A Systematic Review on Deficiencies and Supplementation

Liver lipid accumulation is a hallmark of non-alcoholic fatty liver disease (NAFLD), broadly associated with insulin resistance. Inositols (INS) are ubiquitous polyols implied in many physiological functions. They are produced endogenously, are present in many foods and in dietary supplements. Alterations in INS metabolism seems to play a role in diseases involving insulin resistance such as diabetes and polycystic ovary syndrome. Given its role in other metabolic syndromes, the hypothesis of an INS role as a supplement in NAFLD is intriguing. We performed a systematic review of the literature to find preclinical and clinical evidence of INS supplementation efficacy in NAFLD patients. We retrieved 10 studies on animal models assessing Myoinosiol or Pinitol deficiency or supplementation and one human randomized controlled trial (RCT). Overall, INS deficiency was associated with increased fatty liver in animals. Conversely, INS supplementation in animal models of fatty liver reduced hepatic triglycerides and cholesterol accumulation and maintained a normal ultrastructural liver histopathology. In the one included RCT, Pinitol supplementation obtained similar results. Pinitol significantly reduced liver fat, post-prandial triglycerides, AST levels, lipid peroxidation increasing glutathione peroxidase activity. These results, despite being limited, indicate the need for further evaluation of INS in NAFLD in larger clinical trials.

Targeting the Inositol Pyrophosphate Biosynthetic Enzymes in Metabolic Diseases

In mammals, a family of three inositol hexakisphosphate kinases (IP6Ks) synthesizes the inositol pyrophosphate 5-IP7 from IP6. Genetic deletion of Ip6k1 protects mice from high fat diet induced obesity, insulin resistance and fatty liver. IP6K1 generated 5-IP7 promotes insulin secretion from pancreatic β-cells, whereas it reduces insulin signaling in metabolic tissues by inhibiting the protein kinase Akt. Thus, IP6K1 promotes high fat diet induced hyperinsulinemia and insulin resistance in mice while its deletion has the opposite effects. IP6K1 also promotes fat accumulation in the adipose tissue by inhibiting the protein kinase AMPK mediated energy expenditure. Genetic deletion of Ip6k3 protects mice from age induced fat accumulation and insulin resistance. Accordingly, the pan IP6K inhibitor TNP [N2-(m-trifluorobenzyl), N6-(p-nitrobenzyl)purine] ameliorates obesity, insulin resistance and fatty liver in diet induced obese mice by improving Akt and AMPK mediated insulin sensitivity and energy expenditure. TNP also protects mice from bone loss, myocardial infarction and ischemia reperfusion injury. Thus, the IP6K pathway is a potential target in obesity and other metabolic diseases. Here, we summarize the studies that established IP6Ks as a potential target in metabolic diseases. Further studies will reveal whether inhibition of this pathway has similar pleiotropic benefits on metabolic health of humans.

Phytic acid actions on hepatic lipids and gut microbiota in rats fed a diet high in sucrose is influenced by dietary fat level

Phytic acid (PA) or myoinositol intake was recently reported by our group to suppress hepatic lipogenic gene expression and modulate gut microbiota in rats fed a high-sucrose diet (HSC). The aim of this study was to investigate the effect of PA and dietary fat level on fatty liver and gut microbiota in rats fed an HSC diet. Male Sprague-Dawley rats were fed a high-fat (HF), HSC diet or a low-fat (LF), HSC diet with or without 1.02% sodium PA for 12 days. Hepatic lipid levels, hepatic enzyme activity, and expression of the enzymes and transcriptional factors related to lipid metabolism, cecal organic acids, and fecal microbiota were evaluated. PA intake depressed hepatic total lipid and triglyceride levels; reduced hepatic activity and expression of lipogenic enzymes; elevated fecal proportion of Lactobacillus spp; and increased cecal succinate level in rats fed the LF diet. The HF diet, when compared with the LF diet, depressed hepatic total lipid and triglyceride levels; reduced hepatic activity and expression of lipogenic enzymes; increased hepatic expression of carnitine palmitoyl-transferase 1a and cAMP-responsive element binding protein 3-like 3; and elevated fecal proportions of Lactobacillus spp and Bifidobacterium spp. In the HF diet groups, PA intake did not affect the factors associated with hepatic lipid metabolism and gut microbiota. In conclusion, dietary fat level could change the effect of PA on hepatic lipid metabolism and gut microbiota and, in turn, could alter the degree of nutritional importance of PA in rats fed an HSC diet.

The uses of microbial phytase as a feed additive in poultry nutrition – a review

Most of the phosphorus (P) in feed ingredients is present as phytate, which is poorly available for absorption in the gastrointestinal tract of different poultry species due to the lack of endogenous phytase. The supplementation of phytase increases the utilization of P by hydrolyzing phytate, which consequently may reduce the excretion of P in the environment. In addition, it has been suggested that phytase may improve the feed utilization, weight gain, egg production and egg traits, nutrient digestibility, energy availability, retention of important minerals in blood and bones. Thus, the effectiveness of phytase on performance and Ca and P absorption in layer chickens fed corn-soybean based diets has been well recognized. The current review briefly discusses the supplementation of phytase in the diet of poultry on performance and egg production and characteristics as well as amino acids and minerals availability.

Intake of phytic acid and myo-inositol lowers hepatic lipogenic gene expression and modulates gut microbiota in rats fed a high-sucrose diet

Dietary phytic acid (PA) was recently reported by our group to suppress hepatic lipogenic gene expression and modulate gut microbiota in rats fed a high-sucrose (HSC) diet. The present study aimed to investigate whether the modulatory effects of PA depend on the dietary carbohydrate source and are attributed to the myo-inositol (MI) ring of PA. Male Sprague-Dawley rats were fed an HSC or a high-starch (HSR) diet with or without 1.02% sodium PA for 12 days. Subsequently, the rats were fed the HSC diet, the HSC diet containing 1.02% sodium PA or an HSC diet containing 0.2% MI for 12 days. The HSC diet significantly increased the hepatic triglyceride (TG) concentration as well as the activity and expression of hepatic lipogenic enzymes compared with the HSR diet. The increases were generally suppressed by dietary PA with a concomitant increase in the fecal and cecal ratios of Lactobacillus spp. In rats fed the HSR diet, PA intake did not substantially affect the factors associated with hepatic lipid metabolism or gut microbiota composition. The effects of MI intake were similar to that of PA intake on hepatic lipogenesis and gut microbiota in rats fed the HSC diet. These results suggest that dietary PA downregulates hepatic lipogenic gene expression and modulates gut microbiota composition in rats fed an HSC diet but not in rats fed an HSR diet. The MI ring of PA may be responsible for the effects of PA intake on hepatic lipogenic gene expression and gut microbiota.

Dietary phytic acid prevents fatty liver by reducing expression of hepatic lipogenic enzymes and modulates gut microflora in rats fed a high-sucrose diet

OBJECTIVES

The aim of this study was to investigate the effect of phytic acid (PA) on fatty liver and gut microflora in rats fed a high-sucrose (HSC) diet.

METHODS

Three groups of rats were fed a high-starch (HSR) diet or an HSC diet with or without 1.02% sodium PA for 12 d. We evaluated hepatic weight, total lipids, and triacylglycerol (TG) levels, the activities and expression of hepatic lipogenic enzymes (glucose-6-phosphate dehydrogenase, malic enzyme 1, and fatty acid synthetase), and fecal microflora.

RESULTS

The HSC diet significantly increased hepatic total lipids and TG levels, and the activities and expression of the hepatic lipogenic enzymes compared with the HSR diet. These upregulations were clearly suppressed by dietary PA. Consumption of PA elevated the fecal ratio of Lactobacillus spp. and depressed the ratio of Clostridium cocoides, and suppressed the elevation in the ratio of C. leptum induced by the HSC diet.

CONCLUSION

This work showed that dietary PA ameliorates sucrose-induced fatty liver through reducing the expression of hepatic lipogenesis genes and modulates gut microflora in rats.

New hypotheses for the health-protective mechanisms of whole-grain cereals: what is beyond fibre?

Epidemiological studies have clearly shown that whole-grain cereals can protect against obesity, diabetes, CVD and cancers. The specific effects of food structure (increased satiety, reduced transit time and glycaemic response), fibre (improved faecal bulking and satiety, viscosity and SCFA production, and/or reduced glycaemic response) and Mg (better glycaemic homeostasis through increased insulin secretion), together with the antioxidant and anti-carcinogenic properties of numerous bioactive compounds, especially those in the bran and germ (minerals, trace elements, vitamins, carotenoids, polyphenols and alkylresorcinols), are today well-recognised mechanisms in this protection. Recent findings, the exhaustive listing of bioactive compounds found in whole-grain wheat, their content in whole-grain, bran and germ fractions and their estimated bioavailability, have led to new hypotheses. The involvement of polyphenols in cell signalling and gene regulation, and of sulfur compounds, lignin and phytic acid should be considered in antioxidant protection. Whole-grain wheat is also a rich source of methyl donors and lipotropes (methionine, betaine, choline, inositol and folates) that may be involved in cardiovascular and/or hepatic protection, lipid metabolism and DNA methylation. Potential protective effects of bound phenolic acids within the colon, of the B-complex vitamins on the nervous system and mental health, of oligosaccharides as prebiotics, of compounds associated with skeleton health, and of other compounds such as alpha-linolenic acid, policosanol, melatonin, phytosterols and para-aminobenzoic acid also deserve to be studied in more depth. Finally, benefits of nutrigenomics to study complex physiological effects of the 'whole-grain package', and the most promising ways for improving the nutritional quality of cereal products are discussed.

Effect of dietary sodium phytate and microbial phytase on the lipase activity and lipid metabolism of broiler chickens

The objective of the present study was to investigate the effect of dietary phytate and microbial phytase on the lipase activity, lipid metabolism and mRNA expressions of fatty acid synthase (FASN) and leptin in broiler chickens. The study was conducted as a 2 x 3 factorial arrangement of treatments with phytate phosphorus at 0.20 and 0.40 % (added as the sodium phytate) and supplemental microbial phytase at 0, 500, or 1000 phytase units/kg. The results showed that phytase improved (P < 0.05) the growth performance and ileal digestibility of nutrients of broilers, but phytate had no effect (P>0.05) on these parameters, except the decrease (P < 0.01) in the digestibility of Ca. Phytate decreased (P < 0.05) the lipase activity, serum total cholesterol (T-CHO) and hepatic TAG, and elevated (P < 0.01) serum NEFA and HDL cholesterol. Phytase decreased (P < 0.05) serum NEFA, but increased (P < 0.01) serum T-CHO and hepatic TAG. Phytate and phytase also influenced (P < 0.01) the mRNA expressions of leptin in the liver. There were significant (P < 0.05) interactions of phytate and phytase on the concentrations of serum TAG and LDL cholesterol, hepatic NEFA and T-CHO, and the mRNA expressions of FASN. The results suggest that phytate and phytase can affect lipase activity and lipid metabolism of broiler chickens.

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.

Effect of diet containing phytate and phytase on the activity and messenger ribonucleic acid expression of carbohydrase and transporter in chickens

The effect of dietary phytate and phytase on carbohydrase activity and hexose transport was investigated in broiler chickens. Diets containing phytate P (2.2 or 4.4 g/kg) with different phytase dose rates (0, 500, or 1,000 phytase units/kg) were fed to 504 female Cobb chicks for 3 wk. Diets containing high phytate concentrations depressed (P < 0.05) BW and G:F, whereas phytase supplementation improved (P < 0.05) the performance of birds. In the duodenum, phytate decreased (P < 0.05) the activities of disaccharidases, Na(+)K(+)-ATPase, and glucose concentrations by 5 to 11%, but phytase enhanced (P < 0.05) the concentrations of amylase, sucrase, maltase, Na(+)K(+)-ATPase, and glucose by 5 to 30%. In the jejunum, phytate decreased (P < 0.05) the concentrations of amylase, sucrase, Na(+)K(+)-ATPase, and glucose by 10 to 22%, and phytase alleviated the negative effect of phytate on the above variables. Ingestion of diets containing phytate also decreased (P < 0.05) serum amylase activity and glucose concentration, and phytase enhanced (P < 0.05) serum concentrations of amylase, sucrase, maltase, Na(+)K(+)-ATPase, and glucose. There were also interactions (P < 0.05) between phytate and phytase on the concentrations of serum amylase, duodenal amylase, sucrase, and jejunal glucose. Enzymatic analysis at a molecular level showed that neither phytate nor phytase influenced the mRNA expression of sucrase-isomaltase in the small intestine. Also, the investigation into the sodium glucose cotransporter gene may challenge the mechanism by which phytate interferes with glucose utilization, as partly indicated by bird performance, and transmembrane transport because diets containing increased phytate upregulated (P < 0.05) the mRNA expression of the sodium glucose cotransporter gene in duodenum and did not influence it in the jejunum. These results indicate that phytate can impair endogenous carbohydrase activity and digestive competence, and phytase can ameliorate these effects for chickens.

In vivo metabolic effects of naringenin in the ethanol consuming rat and the effect of naringenin on adipocytes in vitro

Naringenin is a bioactive flavanone involved in the inhibition of drug metabolism which exhibits antioxidant, anti-inflammatory and anticancerogenic properties and which recently appeared to be a factor mitigating the hyperlipidaemic effects in rats and rabbits. In the performed experiment, the effect of naringenin, administered intragastrically (50 mg/kg) for 2 weeks to normal and ethanol drinking rats, on insulin and leptin levels and on some metabolic parameters was investigated. Naringenin did not change the hormone levels in any group of rats. Blood glucose, triglyceride, total, esterified and free cholesterol and high-density lipoprotein-cholesterol concentrations were also unaffected by this compound. Only free fatty acids were elevated after the naringenin treatment in the water-drinking rats. In spite of unchanged glucose and insulin concentrations in blood, the tested flavanone reduced the glucose/insulin ratio in ethanol-receiving rats. Liver triglycerides, elevated due to ethanol ingestion, were partially normalized by naringenin. Other tested parameters like liver glycogen and cholesterol, muscle triglycerides and glycogen were not altered in any group of rats. The influence of naringenin (62.5, 125, 250 and 500 microM) on basal and insulin-stimulated glucose conversion to lipids (lipogenesis) as well as on basal and epinephrine-stimulated glycerol release (lipolysis) in the isolated rat adipocytes was also tested. The basal and the stimulated lipogenesis tended to be decreased in the presence of the flavanone (250 microM). This inhibitory effect intensified and was statistically significant at the highest concentration of naringenin. The tested compound did not evoke any effect on basal lipolysis while the epinephrine-stimulated process was limited at the highest concentration of the flavanone. Naringenin (62.5, 125, 250 and 500 microM) had no effect on leptin secretion from the isolated rat adipocytes. Results obtained in our studies demonstrate that naringenin exerts a very weak influence on carbohydrate and lipid metabolism of normal and ethanol-consuming rats and on metabolism of isolated rat adipocytes.

Protection against cancer by dietary IP6 and inositol

Inositol hexaphosphate (IP(6)) is a naturally occurring polyphosphorylated carbohydrate, abundantly present in many plant sources and in certain high-fiber diets, such as cereals and legumes. In addition to being found in plants, IP(6) is contained in almost all mammalian cells, although in much smaller amounts, where it is important in regulating vital cellular functions such as signal transduction, cell proliferation, and differentiation. For a long time IP(6) has been recognized as a natural antioxidant. Recently IP(6) has received much attention for its role in cancer prevention and control of experimental tumor growth, progression, and metastasis. In addition, IP(6) possesses other significant benefits for human health, such as the ability to enhance immune system, prevent pathological calcification and kidney stone formation, lower elevated serum cholesterol, and reduce pathological platelet activity. In this review we show the efficacy and discuss some of the molecular mechanisms that govern the action of this dietary agent. Exogenously administered IP(6) is rapidly taken up into cells and dephosphorylated to lower inositol phosphates, which further affect signal transduction pathways resulting in cell cycle arrest. A striking anticancer action of IP(6) was demonstrated in different experimental models. In addition to reducing cell proliferation, IP(6) also induces differentiation of malignant cells. Enhanced immunity and antioxidant properties also contribute to tumor cell destruction. Preliminary studies in humans show that IP(6) and inositol, the precursor molecule of IP(6), appear to enhance the anticancer effect of conventional chemotherapy, control cancer metastases, and improve quality of life. Because it is abundantly present in regular diet, efficiently absorbed from the gastrointestinal tract, and safe, IP(6) + inositol holds great promise in our strategies for cancer prevention and therapy. There is clearly enough evidence to justify the initiation of full-scale clinical trials in humans.

Effects of dietary myo-inositol, D-chiro-inositol and L-chiro-inositol on hepatic lipids with reference to the hepatic myo-inositol status in rats fed on 1,1,1-trichloro-2,2-bis (p-chlorophenyl) ethane

The effects of dietary 0.2% inositol stereoisomers on the hepatic lipids and myo-inositol (MI) status in rats fed with 1,1,1-trichloro-2,2-bis (p-chlorophenyl) ethane (DDT) were investigated. Dietary MI reduced the hepatic lipids in the rats fed with DDT. Dietary D-chiro-inositol (DCI) and L-chiro-inositol (LCI) both had a promoting effect on the increase in hepatic lipids due to DDT feeding. Dietary MI enhanced the hepatic free MI level and the phosphatidylinositol/phosphatidylcholine ratio, but dietary DCI reduced the level and ratio.

Phytate intake and molar ratios of phytate to zinc, iron and calcium in the diets of people in China

OBJECTIVE

To assess the phytate intake and molar ratios of phytate to calcium, iron and zinc in the diets of people in China.

DESIGN

2002 China Nationwide Nutrition and Health Survey is a cross-sectional nationwide representative survey on nutrition and health. The information on dietary intakes was collected using consecutive 3 days 24 h recall by trained interviewers.

SUBJECTS

The data of 68 962 residents aged 2-101 years old from 132 counties were analyzed.

RESULTS

The median daily dietary intake of phytate, calcium, iron and zinc were 1186, 338.1, 21.2 and 10.6 mg, respectively. Urban residents consumed less phytate (781 vs 1342 mg/day), more calcium (374.5 vs 324.1 mg/day) and comparable amounts of iron (21.1 vs 21.2 mg/day) and zinc (10.6 vs 10.6 mg/day) than their rural counterparts. A wide variation in phytate intake among residents from six areas was found, ranging from 648 to 1433 mg/day. The median molar ratios of phytate to calcium, iron, zinc and phytate x calcium/zinc were 0.22, 4.88, 11.1 and 89.0, respectively, with a large variation between urban and rural areas. The phytate:zinc molar ratios ranged from 6.2 to 14.2, whereas the phytate x calcium/zinc molar ratios were from 63.7 to 107.2. The proportion of subjects with ratios above the critical values of phytate to iron, phytate to calcium, phytate to zinc and phytate x calcium/zinc were 95.4, 43.7, 23.1 and 8.7%, respectively. All the phytate/mineral ratios of rural residents were higher than that of their urban counterparts.

CONCLUSIONS

The dietary phytate intake of people in China was higher than those in Western developed countries and lower than those in developing countries. Phytate may impair the bioavailability of iron, calcium and zinc in the diets of people in China.

Phytic acid-induced metabolic changes in the rat

Phytic acid (PA) is present in considerable amounts in the seeds of many plant species consumed by animals. Little is known about its influence on metabolic processes. In the performed experiment the effect of rats feeding a standard laboratory diet (Murigran) with increasing supplements of PA on some hormones and biochemical parameters was tested. Male Wistar rats were divided into five groups of eight animals each. In the first group (control) rats were fed a diet without any supplement whereas the groups II-V received food with added PA: 0.1, 0.2, 0.3 and 1%. After 20 days animals were decapitated, blood serum, liver and tight muscles were sampled. In rats fed a diet enriched in PA the concentration of thyroid hormones was diminished. Simultaneously, T(3)/T(4) ratio was slightly reduced. These changes were accompanied by a rise in blood glucose level and an augmentation in liver and muscle glycogen stores and were found in spite of unchanged blood insulin. Consumption of food with increased amounts of PA resulted in a substantial reduction of liver triglyceride content, but serum triglycerides were not affected. In rats from groups II and III serum free-fatty acids concentration was reduced. However, in animals receiving highest PA supplement this effect was not observed. Serum calcium and magnesium were not affected by PA. Serum iron was significantly reduced, but only in rats on the highest supplement of the tested compound. Results obtained in this experiment clearly indicate that the PA is able to induce hormonal and metabolic changes in animals. These changes seem to result not only from reduced bioavailability of minerals but also from interactions of PA with nutrients and enzymes in the liver.

Cancer inhibition by inositol hexaphosphate (IP6) and inositol: from laboratory to clinic

Inositol hexaphosphate (IP6) is a naturally occurring polyphosphorylated carbohydrate that is present in substantial amounts in almost all plant and mammalian cells. It was recently recognized to possess multiple biological functions. A striking anticancer effect of IP6 was demonstrated in different experimental models. Inositol is also a natural constituent possessing moderate anticancer activity. The most consistent and best anticancer results were obtained from the combination of IP6 plus inositol. In addition to reducing cell proliferation, IP6 increases differentiation of malignant cells, often resulting in a reversion to normal phenotype. Exogenously administered IP6 is rapidly taken into the cells and dephosphorylated to lower-phosphate inositol phosphates, which further interfere with signal transduction pathways and cell cycle arrest. Enhanced immunity and antioxidant properties can also contribute to tumor cell destruction. However, the molecular mechanisms underlying this anticancer action are not fully understood. Because it is abundantly present in regular diet, efficiently absorbed from the gastrointestinal tract, and safe, IP6 holds great promise in our strategies for the prevention and treatment of cancer. IP6 plus inositol enhances the anticancer effect of conventional chemotherapy, controls cancer metastases, and improves the quality of life, as shown in a pilot clinical trial. The data strongly argue for the use of IP6 plus inositol in our strategies for cancer prevention and treatment. However, the effectiveness and safety of IP6 plus inositol at therapeutic doses needs to be determined in phase I and phase II clinical trials in humans.

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.

Prolonged fermentation of whole wheat sourdough reduces phytate level and increases soluble magnesium

This work was designed to compare the effects of different leavens (yeast, sourdough, and a mixture of both) on phytic acid (PA) degradation and to assess the repercussions of PA breakdown on phosphorus and magnesium solubility during bread-making. Sourdough fermentation was more efficient than yeast fermentation in reducing the phytate content in whole wheat bread (-62 and -38%, respectively). Furthermore, lactic acid bacteria present in sourdough enhanced acidification, leading to increased magnesium and phosphorus solubility. To intensify phytate breakdown, bran was incubated with microorganisms (yeast or sourdough) before bread-making. Using this new method, the percentage of phytate breakdown was near 90%, whereas 40% of phytate remained in traditional French bread. In conclusion, a prolonged fermentation with sourdough still leads to improved Mg and P solubility by decreasing phytate content and through acidification.