Molecular cloning of chicken hepatic histidase and the regulation of histidase mRNA expression by dietary protein

Chicken hepatic histidase activity varies with dietary protein consumption, but the mechanisms responsible for this alteration in activity are unclear. In the present research, the complete coding sequence and deduced amino acid sequence for chicken histidase was determined from clones isolated from a chicken liver cDNA library. The deduced amino acid sequence of chicken histidase has greater than 85% identity with the amino acid sequences of rat, mouse, and human histidase. In a series of four experiments, broiler chicks were allowed free access for 1.5, 3, 6, or 24 h to a low (13 g/100 g diet), basal (22 g/100 g diet) and high (40 g/100 g diet) protein diet. In the final experiment 5, chicks were allowed free access for 24 h to the basal, high protein diet or the basal diet supplemented with three different levels of l-histidine (0.22 g/100 g diet, 0.43 g/100 g diet or 0.86 g/100 g diet). There were no differences in the expression of the mRNA for histidase at 1.5 h, but at 3 h, histidase mRNA expression was significantly (P < .05) greater in chicks fed the high protein diet compared to chicks fed the low protein diet. At 6 and 24 h, histidase mRNA expression was significantly enhanced in chicks fed the high protein diet, and significantly reduced in chicks fed the low protein diet, compared with chicks fed the basal diet. Histidase mRNA expression was not altered by supplementing the basal diet with histidine. The results suggest that previously observed alterations in the activity of histidase, which were correlated to dietary protein intake, are mediated by rapid changes in the mRNA expression of this enzyme, and are not necessarily related to dietary histidine intake.     

Roles of nuclear receptors in the up-regulation of hepatic cholesterol 7alpha-hydroxylase by cholestyramine in rats

Nuclear receptors are involved in regulating the expression of cholesterol 7alpha-hydroxylase (CYP7A1), however, their roles in the up-regulation of CYP7A1 by cholestyramine (CSR) are still unclear. In the present study, male Wistar rats were divided into four groups and fed [high sucrose + 10% lard diet] (H), [H + 3% CSR diet] (H + CSR), [H + 0.5% cholesterol + 0.25% sodium cholate diet] (C), or [C + 3% CSR diet] (C + CSR) for 2 weeks. Cholestyramine decreased serum and liver cholesterol levels significantly in rats fed C-based diets, but had no effect on these parameters in rats fed H-based diets. Cholestyramine raised hepatic levels of CYP7A1 mRNA and activity in both groups. The gene expression of hepatic ATP-binding cassettes A1 and G5, regulated by liver X receptor (LXR), were unchanged and down-regulated by cholestyramine, respectively. The mRNA levels of the hepatic ATP-binding cassette B11 and short heterodimer partner (SHP), regulated by farnesoid X receptor (FXR), were not changed by cholestyramine. C-based diets, which contained cholesterol and cholic acid, increased SHP mRNA levels compared to H-based diets. Consequently, in rats fed the C+CSR diet, hepatic FXR was activated by dietary bile acids, but the hepatic CYP7A1 mRNA level was increased 16-fold compared to that in rats fed an H diet. These results suggest that cholestyramine up-regulates the expression of CYP7A1 independently via LXR- or FXR-mediated pathways in rats.     

Evaluation of the contribution of dietary cholesterol to hypercholesterolemia in diabetic rats and of sitosterol as a recovery standard for cholesterol absorption

The contribution of dietary cholesterol to hypercholesterolemia in diabetic rats fed chow ad libitum was evaluated. Diabetes was induced with streptozotocin, and the intake, absorption, and subsequent tissue distribution of dietary cholesterol were measured. Absorption was measured as the difference between [3H]cholesterol intake and fecal 3H-labeled neutral sterol excretion, using both [14C]sitosterol (added to diet) and [14C]cholesterol (added to feces) as recovery markers. [3H]Cholesterol absorption was underestimated by 1-3% using [14C]sitosterol as a recovery standard, due to the 7-8% absorption of sitosterol. After 3 weeks of diabetes, rats were hyperphagic, thereby increasing dietary cholesterol intake 2-fold. [3H]Cholesterol absorption was significantly increased from 69% in controls to 78% in diabetics, whereas [14C]sitosterol absorption was unaffected. With increased dietary cholesterol intake and decreased whole body cholesterol synthesis (Diabetes. 1983. 32: 811-819), influx from diet equaled for exceeded influx from synthesis. The amounts of 3H-labeled neutral sterol recovered from the small intestine, periphery, and plasma were increased 3- to 4-fold in the diabetic rats. Furthermore, the degree of hypercholesterolemia in diabetic rats was directly related to the fraction of plasma cholesterol derived from the diet. We conclude that the 2.3-fold increase in absorbed dietary cholesterol resulting from hyperphagia and, to a lesser extent, from increased fractional absorption, contributes to the hypercholesterolemia of diabetic rats fed chow ad libitum.     

Phosphatidylcholine-enriched diet prevents gallstone formation in mice susceptible to cholelithiasis

Cholesterol gallstones affect approximately 10-15% of the adult population in North America. Phosphatidylcholine (PC) is considered to be the main cholesterol solubilizer in bile. This study examined the effect of a PC-enriched diet on gallstone incidence in mice susceptible to cholelithiasis. The result obtained showed that the feeding of a lithogenic (LG) diet for 4 weeks or 8 weeks resulted in cholesterol gallstone incidences of 47% and 89%, respectively. These gallstone incidences were either reduced or prevented when the LG diet was enriched with 2% or 6% PC, respectively. The cholesterol saturation index (CSI) was reduced only in mice fed with LG + 6% PC diet as compared with mice fed the LG diet alone. However, in all groups, the CSI was significantly higher than in mice fed Purina chow diet. The biliary anionic polypeptide fraction (APF) was significantly increased in mice fed the LG + 2% PC diet and was reduced in those fed with LG + 6% PC diet. In conclusion, prevention or delay of gallstone formation was not due to a consistent effect on biliary lipid composition, suggesting a direct effect of PC on cholesterol solubilization and/or the effect of an additional nonlipid biliary component such as APF.     

Inhibition of lecithin:cholesterol acyltransferase activity by synthetic phosphatidylcholine species containing eicosapentaenoic acid or docosahexaenoic acid in the sn-2 position.

Phospholipids isolated from the plasma of monkeys fed a diet enriched in fish oil were poor substrates for cholesteryl ester (CE) synthesis by the lecithin:cholesterol acyltransferase (LCAT) reaction relative to those from animals fed a lard containing diet when the phospholipids were used for the preparation of recombinant particles by cholate dialysis (Parks, J. S., B. C. Bullock, and L. L. Rudel. 1989. J. Biol. Chem. 264: 2545-2551). The purpose of the present study was to directly test the influence of eicosapentaenoic acid (20:5 n-3) and docosahexaenoic acid (22:6 n-3) in the sn-2 position of phosphatidylcholine (PC) on the activity of LCAT. PC species containing 1-palmitoyl-2-oleoyl PC (POPC), 1-palmitoyl-2-linoleoyl PC (PLPC), 1-palmitoyl-2-arachidonoyl PC (PAPC), 1-palmitoyl-2-eicosapentaenoyl PC (PEPC), or 1-palmitoyl-2-docosahexaenoyl PC (PDPC) were purchased or synthesized and made into recombinant particles of uniform size and composition with [14C]cholesterol and apoA-I using the cholate dialysis procedure. The recombinant particles (PC:cholesterol:apoA-I molar ratio = 42:1.9:1) exhibited the following order of reactivity towards purified human LCAT in vitro: POPC greater than PLPC greater than PEPC = PAPC greater than PDPC. The apparent Vmax/Km for recombinant particles containing PEPC and PDPC was 17% and 7% that of particles containing POPC, respectively. There was a linear decrease in CE formation when the percentage of PEPC or PDPC was increased from 0 to 100% relative to POPC in recombinant particles with a constant PC:cholesterol:apoA-I molar ratio, suggesting that the PEPC and PDPC were competitive inhibitors of the LCAT reaction.(ABSTRACT TRUNCATED AT 250 WORDS)     

Is hypercalcemic diet a possible antidote to oral contraceptive-induced hypertension?

Administration of oral contraceptive (OC) has been associated with body fluid retention and in high doses over a long period, promotes hypertension. This present investigation tests the hypothesis that the dietary calcium supplementation increases salt and water excretion in OC (norgestre/ethinylestradiol) treated 32 female albino rats randomly distributed into four (1-4) groups of 8 rats each: Control, OC-treated, OC-treated+ Calcium diet fed and Calcium diet fed only respectively. OC was administered to the appropriate groups by gavage. Experimental diet contained 2.5% calcium supplement. Plasma and urinary [Na+] [K+] were evaluated after 8 weeks of experimentation by flame photometry and plasma [Ca2+] by colorimetric method. OC-treatment induced a significant fall in urinary [Na+]. Water excretion was significantly reduced in these animals (control, 3.1±0.56 Vs OC-treated rats, 1.47±0.16). OC-treated rats had significantly higher plasma [K+] compared to control rats. Calcium supplementation induced increases in plasma [Na+], [K+] and augmented urinary Na+ excretion (OC-treated + Ca2+ diet Vs OC-treated only). Compared with the control rats, high Ca2+ diet fed rats exhibited significant increases in plasma [Na+] and [K+] accompanied by significant decreases in urinary H20 excretion. These results strongly suggest that high dietary Ca2+ supplementation increases salt and water excretion in OC-treated rats and potentially moderates fluid retention and blood pressure in these animals, and may be of clinical significance in OC-induced abnormal fluid retention and perhaps OC-induced hypertension.Keywords: Hypercalcemic-diet, Oral contraceptive, Plasma electrolytes, Hypertension, Female-albino-rats.     

Dietary Genistein Induces Sex-Dependent Effects on Murine Body Weight,Serum Profiles,and Vascular Function of Thoracic Aortae

BackgroundThe influence on, or interaction of, sex and dietary genistein on serum markers of cardiovascular health and cardiovascular function remain unclear.ObjectivesOur purpose was to examine the effects of a genistein-containing diet (600 mg/kg food) (600G) and a genistein-free diet (0G), on cardiovascular risk parameters of male and female mice.MethodsC57BL/6J mice were fed the diets for 1 month, after which time blood pressure, serum markers, and in vitro vascular reactivity was measured.ResultsMales fed the 600G diet gained significantly less weight than males fed the 0G diet (by 1.71 g); diet had no effect on female weight gain. Males fed the 600G diet also exhibited significantly elevated serum insulin (2.9 [0.5] vs 1.8 [0.4] ng/dL), and decreased serum glucose (0.15 [0.01] vs 0.24 [0.02] ng/dL) levels, resulting in a significant increase in the ratio of insulin to glucose; insulin and glucose levels were not changed by dietary genistein in females. Arterial pressure measurements from 0G-fed males were lower than other groups. However, basal vascular reactivity of isolated aortic rings was significantly increased by the 600G diet in both males (from 0.55 [0.03] to 0.94 [0.18] g) and females (from 0.45 [0.04] to 0.78 [0.09] g). Aortic wall thickness was not affected by diet. Norepinephrine-mediated contractility was also greater in aortic rings of male and female mice fed the 600G diet, and differences from the 0G diet persisted in the presence of L-NG-nitroarginine methyl ester but were completely accounted for by increased basal reactivity.ConclusionOur data indicate that 1 month of a 600G or 0G diet significantly alters vascular function independent of sex. In contrast, sex-dependent differences exist in well-established serum markers of cardiovascular health and disease.     

The effect of adlay oil on plasma lipids, insulin and leptin in rat.

This study was designed to investigate the effect of dietary adlay oil on plasma lipids, insulin and lipid peroxidation levels in rats. Twenty-four male Wistar rats fed diet containing adlay oil and cholesterol were studied for 4 weeks. The animals were divided into three groups: (1) 10% lard (control) group; (2) 5% lard + 5% adlay oil (5% adlay oil) group; and (3) 10% adlay oil group. Although there was no significant difference in body weight at the end of the feeding study, rats fed a diet containing adlay oil showed a significant decrease in adipose tissue weight and relative adipose weight. In addition, the rats fed the adlay oil showed significantly decreased low-density lipoprotein cholesterol (LDL-C), insulin, leptin and thiobarbituric acid reactive substance (TBARS) concentrations after 4 weeks of the feeding study. Although a significant decrease in total plasma cholesterol was observed in rats fed the 5% adlay oil diet, no significant difference was observed between the 10% adlay oil and control groups, and neither was a significant difference in liver TBARS concentration found between the dietary groups. Results from this study suggest that dietary adlay oil can reduce leptin, adipose tissue and LDL-C levels in rats.     

Effects of chronic lead and cadmium exposure on blood pressure in occupationally exposed workers

Studies were carried out to determine the effect of dietary vanadium on chicks fed phosphorus deficient and control diets. Vanadium at 50 mg/kg of diet decreased growth of both control and deficient chicks. The high mortality among the phosphorus deficient chicks was significantly alleviated by the presence of vanadium. The increased relative ventricular weights found among the deficient chicks was also alleviated by the presence of dietary vanadium. Vanadium fed at 10 or 20 mg/kg diet did not reduce growth rate but significantly reduced mortality among chicks fed the deficient diet and decreased the relative ventricle weights. Time course studies revealed that chicks are hatched with high relative ventricular weights (.83% of body wt) and remain at that level among chicks fed the phosphorus deficient diet. The addition of vanadium or phosphate to the diet resulted in a progressive decrease in relative ventricular weights. The inclusion of vanadium in the diet resulted in increased serum phosphorus levels among the deficient chicks that may be related to the decrease in mortality and relative ventricle weights.     

Role of hydrophilic bile acids and of sterols on cholelithiasis in the hamster

The effect of various dietary additions such as cholesterol, beta-sitosterol, bile acids, and bile acid analogs on gallstone formation was studied in the hamster. Gallstones were formed in 50% of the animals fed a high glucose, fat-free diet. Administration of 0.2% cholesterol or 1% beta-sitosterol had no effect on the incidence of gallstones. Ursodeoxycholic acid (0.5%) and its analog ursodeoxy-oxazoline [2-(3 alpha, 7 beta-dihydroxy-24-nor-5 beta-cholanyl)-4,4-dimethyl-2- oxazoline] were ineffective in preventing gallstones. Hyodeoxycholic acid and hyodeoxy-oxazoline [2-(3 alpha,6 alpha-dihydroxy-24-nor-5 beta-cholanyl)-4,4-dimethyl-2- oxazoline] at the same dosage effectively prevented gallstones, while the trihydroxy bile acid, hyocholic acid, was not effective. Of all the dietary regimens tested, only hyodeoxycholic acid significantly lowered serum cholesterol. The lithogenic diet produced a five-fold increase in hepatic HMG-CoA reductase activity; this activity was not affected by dietary cholesterol or beta-sitosterol. Hyodeoxycholic acid and hyocholic acid feeding increased the reductase activity by an additional 50% while the other bile acids had no effect. beta-Sitosterol doubled the cholesterol 7 alpha-hydroxylase activity whereas hyodeoxy-oxazoline lowered it. Hyodeoxycholic acid-fed animals had significantly lower cholesterol absorption than the animals on the lithogenic diet alone. Biliary cholesterol content increased dramatically in the animals fed the lithogenic diet and was increased still further by ursodeoxycholic acid, hyodeoxycholic acid, and hyodeoxy-oxazoline. These data show that hyodeoxycholic acid and hyodeoxy-oxazoline do not prevent gallstones by inhibiting hepatic cholesterol synthesis or biliary cholesterol secretion.     

Effects of feeding deoxynivalenol (DON)-contaminated wheat to laying hens and roosters of different genetic background on the reproductive performance and health of the newly hatched chicks

A total of 216 23-week-old laying hens from two different genetic backgrounds (half of the birds were Lohmann brown [LB] and [LSL] hens, respectively) and 24 adult roosters were assigned to a feeding trial to study the effect of increasing concentrations of deoxynivalenol (DON) in the diet (0, 5, 10 mg/kg) on the reproductive performance of hens and roosters, and the health of the newly hatched chicks. Hatchability was adversely affected by the presence of DON in LB hens’ diet, while the hatchability of the LSL chicks was significantly higher than LB chicks. An interaction effect between DON in the hens’ diet and the breed was noticed on fertility, as the fertility was decreased in the eggs of LB hens receiving 10 mg/kg DON in their diet and increased in the eggs of LSL hens fed 10 mg/kg DON. Moreover, spleen relative weight was significantly decreased in the chicks hatched from eggs of hens fed contaminated diets, while gizzard relative weight was significantly decreased in LB chicks with 10 mg/kg DON in their diet compared with the control group. On the other hand, the chicks’ haematology and organ histopathology were not affected by the dietary treatment. Additionally, the presence of DON in the roosters’ diet had no effect on fertility (the percentage of fertile eggs of all laid eggs). Consequently, the current results indicate a negative impact of DON in LB hens’ diet on fertility and hatchability, indicating that the breed of the hens seems to be an additional factor influencing the effect of DON on reproductive performance of the laying hens.     

Effect of increased calcium intake on cardiac and vascular Na(+)-K(+)-ATPase activity in oral contraceptive-treated female Sprague-Dawley rats

The present study aimed at investigating the influence of increased dietary calcium on Na(+)-K(+)-ATPase activity in heart and aorta of female Sprague-Dawley rats treated with oral contraceptive (OC) steroids. Rats were grouped as control (CR), OC-treated and OC+calcium-treated. OC-treated and OC+calcium-treated received a combination of OC steriods (ethinyloestradiol and norgestrel; ig). OC+calcium-treated rats were fed with 2.5% calcium diet, while OC-treated and CR groups were fed on 0.9% calcium diet. The activity of Na(+)-K(+)-ATPase in heart and aorta was significantly lower in OC-treated rats than those in the other groups. OC treatment caused significant increase in plasma glucose and significant decrease in plasma K+ as compared to control group. Decrease in Na(+)-K(+)-ATPase activity and plasma K+ was abrogated by increased calcium intake, while increase in plasma glucose was not normalized by calcium supplementation. Plasma levels of Na+, lipid peroxidation index and ascorbic acid were comparable among the three groups. These results showed that OC treatment could lead to impaired activity of cardiac and vascular Na(+)-K(+)-ATPase, possibly due to reduced plasma K+ level and these effects could be abolished by high calcium diet.     

Whole body and hepatic cholesterol synthesis rates in the guinea-pig: effect of dietary fat quality

The effects of polyunsaturated, monounsaturated and saturated dietary fat on total and hepatic cholesterol synthesis were studied in the guinea-pig. Male Hartley guinea-pigs were fed semi-synthetic diets containing 7.5% (w/w) of either corn oil (CO), olive oil (OL) or lard for a period of 5 weeks and rates of endogenous cholesterol synthesis were determined from the incorporation of [3H]water into digitonin-precipitable sterols (DPS) and by measurement of sterol balance. In addition, total and expressed 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activities were determined in hepatic microsomes. Rates of whole body cholesterol synthesis determined by incorporation of [3H]water into DPS were significantly lower for guinea-pigs on the CO diet with values of 18.7 +/- 1.8 mumol/h (n = 4) vs. 26.7 +/- 4.8 and 24.6 +/- 1.8 mumol/h for animals on the OL (n = 4) and lard (n = 3) diets (P less than 0.001), respectively. Hepatic cholesterol synthesis rates were significantly decreased in animals on the OL diet, whether determined from incorporation of [3H]water into DPS or by analysis of HMG-CoA reductase activity. Hepatic total and free cholesterol levels were not different for animals on the three dietary fats; however, cholesteryl ester levels were 35% lower in guinea-pigs fed the lard diet (P less than 0.02). Sterol balance measurements indicated that whole body cholesterol synthesis rates were not affected by dietary fat quality (51.9 +/- 12.2, 42.8 +/- 7.6 and 51.2 +/- 20.2 mg/kg per day for animals on the CO, OL and lard diets, respectively). This is in striking contrast to the observed reduction in cholesterol synthesis rates for animals on the polyunsaturated CO diet as determined by incorporation of [3H]water into DPS. One possible explanation for the discrepancy between the sterol balance and [3H]water incorporation data is a polyunsaturated fat-mediated effect on energy utilization, which affects the equilibration of NADPH with the body water pool such that the [3H]NADPH has a lower specific activity than body [3H]water.     

Effects of dietary pyrroloquinoline quinone disodium on growth performance,carcass yield and antioxidant status of broiler chicks

Pyrroloquinoline quinone (PQQ), a putative essential nutrient and redox modulator in microorganisms, cell and animal models, has been recognized as a growth promoter in rodents. Growth performance, carcass yield and antioxidant status were evaluated on broiler chickens fed different levels of PQQ disodium (PQQ.Na₂). A total of 784 day-old male Arbor Acres (AA) broilers were randomly allotted into seven dietary groups: negative control group (NC) fed a basal diet without virginiamycin (VIR) or PQQ.Na₂; a positive control group (PC) fed a diet with 15 mg of VIR/kg diet; and PQQ.Na₂ groups fed with 0.05, 0.10, 0.20, 0.40 or 0.80 mg PQQ.Na₂/kg diet. Each treatment contained eight replicates with 14 birds each. The feeding trial lasted for 6 weeks. The results showed that chicks fed 0.2 mg PQQ.Na₂/kg diet significantly improved growth performance comparable to those in PC group, and the feed efficiency enhancement effects of dietary PQQ.Na₂ was more apparent in grower phase. Dietary addition of PQQ.Na₂ had the potential to stimulate immune organs development, and low level dietary addition (<0.1 mg/kg) increased plasma lysozyme level. Broilers fed 0.2 mg PQQ.Na₂/kg diet gained more carcasses at day 42, and had lower lipid peroxide malondialdehyde content and higher total antioxidant power in plasma. The results indicated that dietary PQQ.Na₂ (0.2 mg/kg diet) had the potential to act as a growth promoter comparable to antibiotic in broiler chicks.     

Role of mevalonate-5-pyrophosphate decarboxylase in the regulation of chick intestinal cholesterogenesis

The response to different dietary conditions of the enzymes responsible for the transformation of mevalonic acid to isopentenyl pyrophosphate has been studied for the first time in the small bowel of the chick to elucidate the role of these enzymes in the regulation of intestinal cholesterogenesis. Feeding a 2% cholesterol diet from hatching resulted in a small but significant inhibition of mevalonate-5-pyrophosphate decarboxylase, while mevalonate kinase and mevalonate-5-phosphate kinase remained unaltered. Similar results were obtained for the three enzymes when 13-day-old chicks fed a standard fat-free diet were switched to a 5% cholesterol diet. Starved chicks exhibited lower intestinal decarboxylase activity than chicks fed a standard diet, while refeeding resulted in levels of activity similar or slightly greater than controls. None of the enzymes effecting the conversion of mevalonate to isopentenyl pyrophosphate in the small intestine presented diurnal variations. Results obtained suggest that mevalonate-5-pyrophosphate decarboxylase may play a significant role in the regulation of cholesterol synthesis in the small intestine.     

Echium oil reduces plasma lipids and hepatic lipogenic gene expression in apoB100-only LDL receptor knockout mice

We tested the hypothesis that dietary supplementation with echium oil (EO), which is enriched in stearidonic acid (SDA; 18:4 n-3), the product of Delta-6 desaturation of 18:3 n-3, will decrease plasma triglyceride (TG) concentrations and result in conversion of SDA to eicosapentaenoic acid (EPA) in the liver. Mildly hypertriglyceridemic mice (apoB100-only LDLrKO) were fed a basal diet containing 10% calories as palm oil (PO) and 0.2% cholesterol for 4 weeks, after which they were randomly assigned to experimental diets consisting of the basal diet plus supplementation of 10% of calories as PO, EO or fish oil (FO) for 8 weeks. The EO and FO experimental diets decreased plasma TG and VLDL lipid concentration, and hepatic TG content compared to PO, and there was a significant correlation between hepatic TG content and plasma TG concentration among diet groups. EO fed mice had plasma and liver lipid EPA enrichment that was greater than PO-fed mice but less than FO-fed mice. Down-regulation of several genes involved in hepatic TG biosynthesis was similar for mice fed EO and FO and significantly lower compared to those fed PO. In conclusion, EO may provide a botanical alternative to FO for reduction of plasma TG concentrations.     

Corn fiber oil lowers plasma cholesterol levels and increases cholesterol excretion greater than corn oil and similar to diets containing soy sterols and soy stanols in hamsters

The aims of this study were to compare the cholesterol-lowering properties of corn fiber oil (CFO) to corn oil (CO), whether the addition of soy stanols or soy sterols to CO at similar levels in CFO would increase CO's cholesterol-lowering properties, and the mechanism(s) of action of these dietary ingredients. Fifty male Golden Syrian hamsters were divided into 5 groups of 10 hamsters each, based on similar plasma total cholesterol (TC) levels. The first group of hamsters was fed a chow-based hypercholesterolemic diet containing either 5% coconut oil + 0.24% cholesterol (coconut oil), 5% CO, 5% CFO, 5% CO + 0.6% soy sterols (sterol), or 5% CO + 0.6% soy stanols (stanol) in place of the coconut oil for 4 weeks. The stanol diet significantly inhibited the elevation of plasma TC compared to all other dietary treatments. Also, the CFO and sterol diets significantly inhibited the elevation of plasma TC compared to the CO and coconut oil diets. The CFO, sterol, and stanol diets significantly inhibited the elevation of plasma non-high density lipoprotein cholesterol compared to the CO and coconut oil diets. The stanol diet significantly inhibited the elevation of plasma high density lipoprotein cholesterol (HDL-C) compared to all other dietary treatments. The sterol diet significantly inhibited the elevation of plasma HDL-C compared to the CO and coconut oil diets, whereas the CFO diet significantly inhibited the elevation of plasma HDL-C compared to the coconut oil diet only. No differences were observed between the CFO and CO for plasma HDL-C. There were no differences observed between groups for plasma triglycerides. The CO and CFO diets had significantly less hepatic TC compared to the coconut oil, sterol, and stanol diets. The CO and CFO diets had significantly less hepatic free cholesterol compared to the sterol and stanol diets but not compared to the coconut oil diet; whereas the coconut oil and sterol diets had significantly less hepatic free cholesterol compared to the stanol diet. The CFO, sterol, and stanol diets excreted significantly more fecal cholesterol compared to the coconut oil and CO diets. In summary, CFO reduces plasma and hepatic cholesterol concentrations and increases fecal cholesterol excretion greater than CO through some other mechanism(s) in addition to increase dietary sterols and stanols-possibly oryzanols.     

Eucalyptus leaves powder,antibiotic and probiotic addition to broiler diets: effect on growth performance,immune response,blood components and carcass traits

The study was conducted to investigate the effects of different levels of eucalyptus powder (EP), virginiamycin and probiotic on performance, immunity, blood components and carcass traits of broiler chickens. A total of 250, 1-day-old male broiler chickens (Ross 308) were randomly allocated to five treatments with five replicates and 10 chicks each, as a completely randomized design. The dietary treatments consisted of: basal diet (BD), BD+0.25% EP, BD+0.5% EP, BD+0.01% of diet probiotic (Protexin), BD+0.02% of diet antibiotic (virginiamycin). Dietary supplementation did not affect feed intake, BW gain (BWG) and feed conversion ratio (FCR) during starter and grower phases, but BWG and FCR were affected during the finisher and whole periods (P<0.05).The highest BWG and lowest FCR were obtained in birds fed with virginiamycin and 0.5% EP. Dietary supplementation significantly increased the relative weight of carcass and breast (P<0.05). Treatments had no effect on relative weights of internal organs and small intestine except for bursa that increased by treatments. Relative length of jejunum also increased by treatments (P<0.05). Antibody production against sheep red blood cells did not changed in primary titer (day 35), but it significantly increased in secondary titer (day 42) by 0.5% EP. White blood cell counts were increased and cholesterol decreased by dietary supplementation (P<0.05). In conclusion, the results of this study showed that 0.5% EP served as a useful replacement for antibiotic and would improve performance and immune response of broiler chickens.     

Effect of graded levels of dietary Bacillus toyonensis and Bifidobacterium bifidum supplementation on growth,carcass traits and ileal histomorphometry and microbiota of growing quails

This experiment investigated the role of graded dietary levels of two probiotic strains (Bacillus toyonensis; BT and Bifidobacterium bifidum; BB) on the growth rate, carcass traits, physiological and histological aspects of growing Japanese quail. One thousand and three hundred sixty one-day-old un-sexed Japanese quail chicks were distributed randomly into ten groups. The 1st group served as a control and fed the basal diet without supplement while the 2nd, 3rd, 4th and 5th groups received the control diet supplemented with 0.05, 0.075, 0.10 and 0.125% BT, respectively. The 6th group fed the control diet plus 0.10% BB while the remaining groups (7th to 10th) received the basal diet incorporated with the previous levels of BT rich with 0.05% BB. Dietary supplementation of BT and/or BB increased body weight and gain; however, feed intake and feed conversion were not affected. Amylase activity was significantly elevated in 5th, 7th and 9th groups, while lipase activity was improved in all treatment groups except 3rd and 6th groups. Results obtained concluded that dietary supplementation of BT with or without BB is useful for performance, digestive enzyme activities, blood cholesterols, antioxidant status and ileal histomorphometry and microbiota of growing Japanese quail.     

Effect of phytate in soy protein on the serum and liver cholesterol levels and liver fatty acid profile in rats

Dietary soy protein, in comparison with casein, generally lowers the serum cholesterol concentration in rats fed on a cholesterol-enriched diet, while mixed results were observed in rats fed on a diet free of cholesterol. Soy protein also suppresses the conversion of linoleic acid to arachidonic acid in the rat liver. The present study examines whether phytate, a minor component of a soy protein isolate, is responsible for these beneficial effects of soy protein. Weanling male rats were fed for 4 weeks on a purified diet containing a 20% level of protein (either casein (CAS), soy protein (SOY), phytate-depleted SOY (PDSOY) or phytate-replenished PDSOY (PRSOY)) and cholesterol (0 or 0.5%). The dietary protein source and phytate level only affected the serum and liver cholesterol concentrations when the animals were fed on the cholesterol-enriched diet, being significantly lower in those rats fed on the SOY and PRSOY diets than in those fed on the CAS diet, while the concentrations in the rats fed on the PDSOY diet were intermediate. When the animals were fed on the cholesterol-free diet, the ratio of (20:3n-6 + 20:4n-6)/18:2n-6 in liver phosphatidylcholine, a delta6 desaturation index, was significantly lower in the SOY diet group than in the CAS, PDSOY and PRSOY diet groups. Dietary cholesterol significantly depressed the ratio, but neither depletion nor replenishment of phytate affected the ratio. These results suggest that phytate in soy protein played a limited role in the cholesterol-lowering effect of soy protein and was not involved in the metabolism of linoleic acid.