The protective effects of vitamin C on the DNA damage,antioxidant defenses and aorta histopathology in chronic hyperhomocysteinemia induced rats

The aim of this study was to investigate the protective effect of vitamin C towards hyperhomocysteinemia (hHcy) induced oxidative DNA damage using the comet assay. The increase in plasma homocysteine levels is an important risk factor for vascular and cardiovascular diseases through free radical production. This study was also conducted to investigate the histopathological changes in the thoracic aorta and the oxidant/antioxidant status in heart, liver and kidney tissues.Twenty-four adult male Wistar rats were divided as control, hHcy and hHcy + vitamin C group. Chronic hHcy was induced by oral administration of l-methionine (1 g/kg/day) for 28 days. Vitamin C was given 150 mg/kg/day within the specified days. DNA damage was measured by use of the comet assay in lymphocytes. Levels of malondialdehyde (MDA) and glutathione (GSH) as well as catalase (CAT) and superoxide dismutase (SOD) activities were determined in heart, liver and renal tissues.Results show that l-methionine administration significantly increased % Tail DNA and Mean Tail Moment in hHcy group as compared with other groups. Vitamin C treatment significantly decreased the high MDA levels and increased activity of antioxidant enzymes in tissues. Aortic diameter and thickness of aortic elastic laminae were significantly lower in hHcy + vitamin C group.Comet assay can be used for the assessment of primary DNA damage caused by hHcy. Histopathological findings showed that vitamin C may have a preventive effect in alleviating the negative effects of hHcy. Vitamin C might be useful in the prevention of endothelial dysfunction caused by hHcy.     

Effect of vitamin A supplemented diet on calcium oxalate renal stone formation in rats

ObjectivesTo study the effect of a vitamin A supplemented diet on calcium-oxalate stone formation in rats and to test its expected action in the dissolution of renal calculi.Material and methodsTwenty-four male Wistar rats were randomly divided into three groups of eight rats each. The first group (group A) received a normal diet for six weeks. The second group (group B) was fed a lithogenic diet by the addition of ethylene glycol 0.5% to drinking water for three weeks then a normal diet for three weeks. The third group (group C) received the same lithogenic diet for three weeks then a vitamin A supplemented diet 20 times the normal amount (5.1 mg/100 g of diet) at the three last weeks. One day before the end of treatment, each animal was placed for 24 h in metabolic cage in order to collect urine samples and determine the urinary parameters.ResultsThe glomerular filtration rate and the urinary excretion of citric acid which fell in group B have been restored in group C.ConclusionsThis study shows that a vitamin A supplemented diet at the rate of 20 times standard ration could improve the renal function by restoring the glomerular filtration rate and by increasing the urinary pH and excretion of citric acid.     

Antioxidant and anti-atherogenic activities of three Piper species on atherogenic diet fed hamsters

Atherogenic diet is known to induce high plasma lipid concentration, oxidative stress and early atherosclerosis. Antioxidants have potentials to counter the effect of atherogenic diet.The present research aims at evaluating the antioxidant and anti-atherosclerotic activities of three Piper species (Piper guineense, Piper nigrum and Piper umbellatum) on atherogenic diet fed hamsters.Hamsters divided into 8 groups: normal control, atherosclerotic control and six test groups. The normal animals fed normal rodent chow, the atherosclerotic control animals fed the same rodent chow supplemented with 0.2% cholesterol and 10% coconut oil (high cholesterol diet). The 6 test groups’ animals fed same diet as the atherosclerotic control group but with additional supplementation of 2 graded doses (1 and 0.25 mg/kg body weight, o.p.) of plant extracts for 12 weeks.The atherogenic diet induced a collapse of the erythrocyte antioxidant defense system (significant decrease in superoxide dismutase, catalase and glutathione peroxidase activities). Atherogenic diet also induced an increase in plasma total cholesterol, triglyceride, thiobarbituric acid reactive substances (TBARS), oxidation of low density lipoprotein cholesterol (LDL) and accumulation of foam cells in the aorta a hall mark for atherosclerosis. Administration of the Piper species prevented the collapse of the antioxidant system and the increase of plasma parameters maintaining them towards normality. The Piper species also prevented LDL oxidation by increasing the time (lag time) for its oxidation.The results suggest that these Piper species have significant antioxidant and anti-atherogenic effect against atherogenic diet intoxication.     

Evolution and involution of atherosclerosis and its relationship with vascular reactivity in hypercholesterolemic rabbits

Background and objectivesThe aim of this study is to verify the evolution and involution of experimental atherosclerosis in rabbits through the study of endothelial function, lipids and tissue lipid peroxidation, macro and microscopic quantification of aortic atherosclerosis.MethodsThirty male New Zealand white rabbits were divided into six groups (n = 5): G1 normal diet; G2: hypercholesterolemic receiving 0.5% of cholesterol diet for 4 months; G3: hypercholesterolemic diet for 4 months after normal diet for more 4 months; G4: hypercholesterolemic diet for 4 months plus normal diet and rosuvastatin for 1 month, G5: hypercholesterolemic diet for 4 months plus normal diet and rosuvastatin for 2 months, G6: hypercholesterolemic diet for 4 months plus normal diet and rosuvastatin for 4 months. Rosuvastatin was administered at a dosage of 5 mg dissolved in 150 ml of water daily. At the end of the experiment were measured: total cholesterol (TC), triglycerides (TG), low density lipoprotein (LDL-C), high density lipoprotein (HDL-C), tissue cholesterol (CAO), lipid peroxidation tissue (MDA). Endothelial function (RMAX) was studied in a segment of thoracic aorta, through curve-effect of acetylcholine and sodium nitroprusside. The amount of atherosclerosis was determined by measurement of the arterial lesion, through software, after staining with Sudan IV and histological staining.ResultsIn relation the water the rabbits drank 60–70 ml all day. It was seen significantly increase in all parameters at G2 both biochemical and tissue. In the group G3 it was seen significantly decrease in plasma lipids levels and tissue cholesterol. Treated groups G4, G5 and G6 all showed a decreased plasma lipid levels, only at G6 group it was noted a tissue cholesterol, tissue peroxidation and quantification of atherosclerosis, which showed a significant decrease. In relation the endothelial function only G6 improve significantly.Interpretation and conclusionsOur findings indicated that the treatment with rosuvastatin for 4 months is more efficient because improve the endothelial function significantly.     

Effects of chlorella phospholipid on the aortic collagen and elastin metabolism and on the serum lipid content in rats with experimental arteriosclerosis

Rats treated with 44,800 IU of vitamin D₂ for 4 consecutive days were fed an atherogenic diet in the presence or absence of 1% chlorella phospholipid. Control rats received a basal diet and were administered olive oil. After 2 months the animals were killed and aortic prolyl hydroxylase, lysyl oxidase activity, collagen, elastin, and serum lipid levels were determined. Aortic prolyl hydroxylase activity was significantly decreased in rats receiving the atherogenic diet in the absence of chlorella phospholipid. The aortic collagen and elastin content was lower in rats additionally treated with chlorella phospholipid. Aortic lysyl oxidase activity was significantly decreased in all rats receiving the atherogenic diet. The serum cholesterol level was significantly higher in rats on the atherogenic diet, especially the absence of chlorella phospholipid supplementation. The findings suggest that the administration of chlorella phospholipid may stimulate the degradation of collagen and elastin in the aorta of rats fed an atherogenic diet and that the serum cholesterol lowering effect of chlorella phospholipid is not ascribable to thyroid functions. Furthermore, the results suggest that the aortic degradation rate of elastin was reduced by the atherogenic treatment.     

Toxicity of methimazole on femoral bone in suckling rats: Alleviation by selenium

AimsSelenium has a pharmacological properties and it is well considered as an antioxidant. The present study investigated the potential ability of selenium, used as a nutritional supplement, to alleviate bone impairments in suckling rats whose mothers were treated with methimazole, an antithyroid drug.Main methodsFemale Wistar rats were randomly divided into four groups of six each: group I served as control which received standard diet; group II were rendered hypothyroid by administration of methimazole (250 mg L^?1 in their drinking water); group III received both methimazole (250 mg L^?1 in their drinking water) and selenium (0.5 mg kg^?1 of diet); group IV received 0.5 Na₂SeO₃ mg kg^?1 of diet. Treatments were started from the 14th day of pregnancy until day 14 after delivery.Key findingsMethimazole treatment decreased femur length and weight in 14-day-old rats, when compared to controls. Femur antioxidant enzyme activities, superoxide dismutase, catalase and glutathione peroxidase decreased. Lipid peroxidation recorded an increase revealed by high femur malondialdehyde levels. Methimazole also caused a significant decrease in calcium and phosphorus levels in bone. Yet, in plasma and urine, they increased and decreased inversely. Besides, plasma total tartrate-resistant acid phosphatase was enhanced, while total alkaline phosphatase was reduced. Co-administration of selenium through diet improved the biochemical parameters cited above. Nevertheless, distorted histoarchitecture revealed in hypothyroid rat femur was alleviated by Se treatment.SignificanceThe present study suggests that selenium is an important protective element that may be used as a dietary supplement protecting against bone impairments.     

The role of oxidative stress and inflammatory response in high-fat diet induced peripheral neuropathy

ObjectiveEarlier studies suggest that high-calorie diet is an important risk factor for neuronal damage resulting from oxidative stress of lipid metabolism. In our experimental study of rats under high-fat diet, oxidative stress markers and axonal degeneration parameters were used to observe the sciatic nerve neuropathy. The aim of this study is to evaluate the pathophysiology of neuropathy induced by high-fat diet.MethodsA total of 14 male rats (Wistar albino) were randomly divided into two experimental groups as follows; control group (n = 7) and the model group (n = 7); while control group was fed with standard diet; where the model group was fed with a high-fat diet for 12 weeks. At the end of 12 weeks, the lipid profile and blood glucose levels, interleukin-1β (IL-1), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and transforming growth factor-β (TGF-β) levels were studied. Tissue malondialdehyde (MDA), nitric oxide (NO) levels and super-oxide dismutase (SOD), paraoxonase-1 (PON-1) and glutathione peroxidase (GPx) activities were studied. The distal blocks of the left sciatic nerves were evaluated for histomorphological analysis (including mean axon area, axon numbers, nerve fiber diameters, axon diameters, and thickness of myelin sheets).ResultsBody weights, serum glucose and high-density lipoprotein (HDL) levels of rats were found not statistically significantly different compared between the model and the control groups (p > 0.05). Serum cholesterol, triglyceride, TGF-β and TNF-α levels were significantly higher in the model group when compared with the control group (p < 0.05). IL-1 and IL-6 levels were not statistically significantly different compared between the model group and the control group (p > 0.05). The MDA and NO levels and the SOD and GPx activities of the sciatic nerves in model group were statistically significantly higher than the control group (p < 0.05). In addition, the activities of PON-1 were statistically significantly lower in the model group when compared with the control group (p < 0.05). The difference in the total number of myelinated axons between the control group and the model group was not statistically significant (p > 0.05). The nerve fiber diameter and the thickness of the myelin sheet were statistically significantly lower in the model group when compared with the control group (p < 0.05). The axon diameter and area were significantly decreased in the model group when compared with the control group (p < 0.05).ConclusionOur results support that dyslipidemia is an independent risk factor for the development of neuropathy. In addition, we postulated that oxidative stress and inflammatory response may play an important role in the pathogenesis of high-fat diet induced neuropathy.     

Abresham ameliorates dyslipidemia,hepatic steatosis and hypertension in high-fat diet fed rats by repressing oxidative stress,TNF-α and normalizing NO production

This study was aimed to investigate whether standardized hydroalcoholic extract of abresham (AB) ameliorates dyslipidemia, hepatic steatosis and associated hypertension in rats fed with high-cholesterol/high-fat diet (HFD). HFD (55% calorie from fat and 2% cholesterol) were fed for 45 days to induce dyslipidemia, hepatic steatosis and associated hypertension. After confirmation of hypercholesterolemia (total cholesterol >150 mg/dl) on 30th day, different doses of AB (200–800 mg/kg/day) were administered for next 15 days. HFD administration for 45 days led to cardiometabolic syndrome characterized by significant increase in body weight, total cholesterol, triglyceride, low density lipoprotein cholesterol, TNF-α levels along with decrease in high density lipoprotein cholesterol and serum NO level. Furthermore, HFD resulted in significant increase in systolic arterial pressure, diastolic arterial pressure and mean arterial pressure. In addition, morphological studies revealed hepatic steatosis along with swelling of mitochondria and loss of cristae in hepatocyte and periarteritis in aorta. Treatment with AB for 15 days positively modulated the altered parameters in dose-dependent fashion, though maximum effect was seen at 800 mg/kg. These findings suggest that AB guard against cardiometabolic syndrome in HFD fed rats. It attenuates dyslipidemia, hepatic steatosis and associated hypertension by decreasing oxidative stress, TNF-α and normalizing NO production.     

Clinico-hematological and micronuclear changes induced by cypermethrin in broiler chicks: Their attenuation with vitamin E and selenium

This study was carried out on 90 one-day-old broiler chicks to know clinico-hematological alterations, DNA damage caused by cypermethrin (CY), and attenuation of toxic effects by vitamin E (Vit E) and selenium (Se). Birds were randomly divided into five equal groups. Groups 1–4 received CY (600 ml kg^?1 b.wt) daily for 30 days by crop tubing. In addition to CY, groups 2, 3 and 4 received Vit E (150 mg kg^?1 b.wt), Se (0.25 mg kg^?1 b.wt), and Vit E (150 mg kg^?1 b.wt)+Se (0.25 mg kg^?1 b.wt), respectively. Group 5 served as control. Birds were monitored twice daily for clinical signs. They were weighed and blood samples were collected at experimental days 10, 20 and 30 for hematological studies. CY-treated birds showed more prominent signs of toxicity compared to CY+Vit E, CY+Se and CY+Vit E+Se birds. Body weight in groups 1–3 was significantly (P<0.05) smaller at days 20 and 30 when compared with the control group. Significantly (P<0.001) higher numbers of micronuclei appeared in chicks treated with CY compared to CY+Vit E- and CY+Se-treated birds. Significantly decreased total erythrocyte counts (TEC), hemoglobin (Hb) concentration and packed cell volume (PCV) in all treated groups were recorded. Treated birds suffered from macrocytic hypochromic anemia. Leukocytosis in early stage and later leucopenia was seen in treated birds. It can be concluded that CY induces toxic effects in broilers chicks; however, these toxic effects can be ameliorated by Vit E or Se. Combination of Vit E and Se was more effective to ameliorate toxic effects of cypermethrin.     

The effect of testosterone alone and testosterone + estradiol therapy on bladder functions and smooth muscle/collagen content in surgically menopause induced rats

ObjectivesThe aim of the study was to investigate the effect of testosterone alone and testosterone + estradiol therapy on bladder functions and smooth muscle/collagen content in surgically menopause induced rat model.MethodsThe study included 34 female Sprague-Dawley rats, and the rats were divided into four groups. After bilateral oophorectomy, during a 60 days period, six rats received IM saline injection for one time, as a control group, and nine rats received testosterone undecanoate 100 mg/kg IM for one time, and nine rats received testosterone undecanoate 100 mg/kg IM for one time + daily 0.50 mg nasal spray of 17β estradiol. Ten rats were taken as sham group. Urodynamic studies were performed in all groups before and after the study. The rats were sacrificed after 60 days, and cystometric findings and smooth muscle/collagen ratio of the bladders were compared between the groups.ResultsIncrease in maximal bladder capacity and compliance were significantly higher in the testosterone treatment group and testosterone + estradiol treatment group than in the control group (p = 0.01 and p = 0.002, respectively for bladder capacity; p = 0.04 and p = 0.005, respectively for bladder compliance). Smooth muscle/collagen ratio of the bladders was significantly higher in the testosterone and testosterone + estradiol treatment groups than in the control group (p = 0.04 and p = 0.008, respectively).ConclusionsThis study shows that bladder functions may deteriorate in postmenopausal period. In addition to estrogen replacement therapy, testosterone has a significant role to increase bladder smooth muscle, leading to improvement in bladder functions in postmenopausal women with urogenital system dysfunction.     

Propolis attenuates cobalt induced-nephrotoxicity in adult rats and their progeny

The aim of this study was to evaluate the biochemical changes in cobalt-exposed rats and to investigate the potential role of Tunisian propolis against the cobalt-induced renal damages. Twenty-four pregnant Wistar rats were divided into four groups and were treated as follows: group 1 (control) received distilled water; group 2 received 350 ppm of CoCl₂ in drinking water; group 3 received 350 ppm CoCl₂ in drinking water and a propolis-supplemented diet (1 g/100 g of diet); group 4 received a propolis-supplemented diet (1 g/100 g of diet) without cobalt. In the cobalt group, a significant decrease in body, absolute and relative weights was noted when compared to controls. The administration of cobalt to pregnant rats from the 14th day of pregnancy until day 14 after delivery resulted in an increased level of renal malondialdehyde, a decreased renal content of glutathione and antioxidant enzyme activities such as superoxide dismutase, catalase and glutathione peroxidase in lactating rats and their pups. A statistically significant increase in plasma urea and creatinine serum levels was seen in treated female rats and their pups. Histopathologically, the cobalt-administration induced degenerative changes in the kidney of lactating rats and their pups. When compared with cobalt-treated rats, those receiving the propolis supplementation (along with cobalt-treatment) had lower malondialdehyde levels, higher antioxidant activities and the cobalt-related histopathological changes in the kidneys were at lower severity.Our results suggested that the propolis might be a potential candidate agent against cobalt-induced nephrotoxicity in adult and juvenile rats when administered to female rats during the late pregnancy and the early postnatal period.     

Hematological effects of arsenic in rats after subchronical exposure during pregnancy and lactation: The protective role of antioxidants

Free radicals production is involved in the toxicity of arsenic. The aim of this study was to determine whether biochemical changes occurred in the blood of arsenic-exposed pups during gestation and lactation, and additionally to investigate the potential beneficial role of the administration of certain antioxidants against arsenic exposure damage. Pregnant wistar rats received the following treatments as drinking water: (1) distilled water; (2) arsenic (50 mg/L); (3) antioxidants: zinc (20 mg/L) + vitamin C (2 g/L) + vitamin E (500 mg/L); (4) arsenic (50 mg/L) + antioxidants: zinc (20 mg/L) + vitamin C (2 g/L) + vitamin E (500 mg/L). We found a normocytic and normochromic anemia as well as a significant increase in hemolysis, TBARS production and catalase activity in the blood of arsenic intoxicated pups. Moreover, this metalloid produced a significant increase of serum cholesterol, triglicerids and urea levels whereas the proteins diminished. These effects were palliated in some extent by the coadministration of vitamins and zinc. Our findings suggest that administration of antioxidants during gestation and lactation could prevent some of the negative effects of arsenic.     

Potential Value of Vitamin E in Cancer Patients with Venous Access Devices

BackgroundVitamin E has antiplatelet, fibrinolytic and endotoxin properties that may help avoid the problems of occlusion or inability to withdraw blood from port VADs.PurposeDisseminate information about the non-traditional therapeutic use of vitamin E associated with care of Venous Access Devices (VAD) in patients with cancer.MethodologyIn-person focus groups. Sample of 22 cancer patients who had port Venous Access Devices (VAD).FindingsFourteen percent (N = 3) of patients felt that taking vitamin E, 400–800 IU per day orally, in capsule form, avoided the problems of occlusion or inability to withdraw blood from their current VAD.Practice ImplicationsThe effects of vitamin E on occlusion and inability to withdraw blood in caring for patients who have port VADs, requires further investigation.     

EphA2 knockdown attenuates atherosclerotic lesion development in ApoE−/− mice

BackgroundThe inflammatory response of vascular endothelial cells plays important roles in the initiation and progression of atherosclerotic lesions. EphA2 receptor activation promotes the endothelial cell inflammatory response, and its expression is increased in the endothelial cell layer of atherosclerotic plaques. However, the association between EphA2 and atherosclerosis has not been determined.MethodsEight-week-old male ApoE^−/− mice were systemically infected with adenoassociated virus serotype 9 carrying a small hairpin RNA specifically targeting the EphA2 gene to knock down EphA2 expression in aortic endothelial cells. These mice were then fed a high-cholesterol diet for 12 weeks. Blood was collected for the measurement of plasma lipids. The aortas were harvested to evaluate the atherosclerotic lesion size, macrophage components, and expression of proinflammatory genes using Oil Red O staining, immunofluorescence staining, and molecular biology analysis.ResultsThe lesions formed in the entire aorta and aortic sinus of the ApoE^−/− mice with EphA2 knockdown were significantly smaller than those in the control mice (10.7% ± 3.1% versus 25.1% ± 4.2%; 0.51 ± 0.02 mm² versus 0.85 ± 0.03 mm²; n = 10; P < .05). Furthermore, the lesions in the ApoE^−/− mice with EphA2 knockdown displayed reduced inflammation compared with the control mice, as reflected by the decreased macrophage infiltration (8.2% ± 2.9% versus 22.7% ± 4%; n = 10; P < .05); decreased nuclear factor-κβ activation; and diminished expression of vascular cell adhesion molecule-1, E-selectin, and monocyte chemotactic protein-1 (all P < .05).ConclusionsOur data demonstrate that the EphA2 receptor silencing attenuates the extent and inflammation of atherosclerotic lesions in ApoE^−/− mice. Thus, EphA2 knockdown in endothelial cells represents a novel therapeutic strategy for patients with atherosclerosis.     

Protective effect of light emitting diode phototherapy on fluorescent light induced retinal damage in Wistar strain albino rats

BackgroundArtificial light at night alters retinal physiology. Several studies have shown that light emitting diode phototherapy protects the retina from the damaging effects of acute light exposure.ObjectiveThe aim of this study has been to elucidate the protective effects of 670 nm LED light on retinal damage induced by chronic fluorescent light in Wistar rats.MethodsMale Wistar albino rats were divided into four groups: group 1 were control (CL), group 2, 3 and 4 were exposed to fluorescent light (FL), LED preexposure + fluorescent light exposure (LL) and only LED light exposure (OL) respectively. All animals were maintained in their specific exposure regime for 30 days. Fluorescent light of 1800 lx was exposed between 8 pm to 8 am. Rats were exposed to therapeutic LED light of 670 nm of 9 J/cm² at 25 mW/cm² for 6 min duration. Histopathological changes in the retina were studied.ResultsAnimals of the FL group showed a significant reduction in the outer nuclear layer thickness and cell count in addition to the total thickness of the retina. LL group which were exposed to 670 nm LED prior to exposure to fluorescent light showed a significant decrease in the degree of damage.Conclusions670 nm LED light preexposure is protective to retinal cells against fluorescent light-induced damage.     

Effect of cyclic tension on the biomechanical properties of flexor tendon grafts. Results of an ex-vivo porcine study

BackgroundAutologous flexor tendons are widely used for anterior cruciate ligament (ACL) reconstruction. Pretension of the graft before fixation has been described as part of the surgical technique, nevertheless there is no consensus on the type and amount to tension needed to increase the stiffness without affecting its biomechanical properties.Our hypothesis is cyclic tension increases flexor tendon stiffness without affecting its ultimate failure at maximum loads (UFML).MethodsForty-five flexor digitorum profundus tendons harvested from domestic pigs (Sus scrofa domestica) were randomly divided into three groups: E1 (n = 15), E2 (n = 15) and C (n = 15). Groups E1 and E2 were subjected to 50 cyclic loads at a 1 Hz frequency, at 70 N and 100 N respectively, group C was not intervened. The three groups were then tested for UFML. Cyclic loads and measurements were performed using a Stress-Strain machine (SST 1.0 Kinetecnic ^®). Results were analyzed using GrapgPad statistical software. Groups were compared using Mann-Whitney test with a 95% confidence interval.ResultsSignificant increased stiffness for group E1 (p = 0.02) and group E2 ( p < 0.01) when compared to group C. The stiffness of group E2 was also significantly higher than E1 (p = 0.03). There was a significant reduction on the UFML between group E2 and C (p < 0.01), which was not observed when comparing groups E1 and C.ConclusionCyclic loads at 70 N result in an increased stiffness of flexor tendons without affecting its ultimate failure at maximum loads. Cyclic loads at higher tensions might cause a deleterious effect on the biomechanical properties of flexor tendon grafts.     

Postprandial ghrelin responses are associated with the intermeal interval in time-blinded normal weight men,but not in obese men

ObjectiveTo investigate the relation between ghrelin responses and meal initiation and the effects of BMI and energy status on this.DesignThe experiment had a randomised, cross-over design.Setting and subjectsNine normal-weight (age: 33.2 ± 4.8 y, BMI: 23.2 ± 0.5 kg/m²) and eleven obese (age: 40.8 ±4.7 y, BMI: 33.2 ± 0.8 kg/m²) healthy men were recruited from a pool of volunteers and by advertisements.InterventionsSubjects followed a three-day energy restrictive and a three-day energy balanced diet separated by one month. Each diet was followed by a time-blinded (overnight) stay at the research facility. Subjects received a breakfast (preload) and were instructed to ask for lunch when they felt hungry. Ghrelin, insulin, glucose, free fatty acids, appetite, IMI and energy intake during lunch were assessed.ResultsPostprandial decreases in ghrelin (r = ? 0.54; p < 0.05) and the AUC of the ghrelin response (r = ? 0.57, p = 0.01) were associated with the intermeal interval, independent of diet, but in normal weight subjects only. Lunch request was preceded by an increase in ghrelin, reaching at least 93% of fasting values. These preprandial increases in ghrelin were correlated with IMI, after energy restriction only. Ghrelin concentrations but not changes in ghrelin were correlated with appetite.ConclusionMeal-related changes in ghrelin are correlated with the IMI in normal weight subjects only, independent of diet. Ghrelin concentrations may need to reach a certain threshold level before the next meal is initiated.SponsorshipSupported by Dutch Ministry of Education, Culture and Science, Dutch Ministry of Health, Welfare and Sport and Danone Research.     

The effect of prolonged oral exposure of cockerels to disinfectant (Iodosteryl®) on induction of oxidative stress and liver damage

This study was designed to investigate the effect of prolonged oral exposure of cockerels to disinfectant (Iodosteryl^®) present in drinking water and its ability to induce liver damage and oxidative stress. Thirty-two healthy birds were used for this study. They were grouped into four groups of eight per group. Group I received 10 ml/kg body weight of physiological saline. Groups II, III and IV received 1 part per million, 2 part per million and 4 part per million of Iodosteryl^® in their drinking water for six weeks. The results revealed significant (P < 0.05) increase in alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase activities in a dose-dependent manner in birds administered with Iodosteryl^® when compared with control. Significant (P < 0.05) increase in sodium and potassium ions was obtained from birds that received Iodosteryl^® (4 part per million) compared with control. Also, there was significant (P < 0.05) increase in total cholesterol, triglycerides, high density lipoprotein and low density lipoprotein levels in all treatment groups (1, 2 and 4 part per million) compared with control. Serum blood urea nitrogen levels increased significantly (P < 0.05) in a dose-dependent manner. Biologic markers of oxidative stress (malondialdehyde and hydrogen peroxide generation) increased significantly with concomitant significant (P < 0.05) decrease in serum glutathione level in a dose-dependent manner when compared with control. Histological sections revealed hepatic congestion, vacuolation and fibrosis at varying concentration of Iodosteryl^®. Overall, Iodosteryl^® induced hepatic damage, increased oxidative stress and decreased antioxidant defense system; hence exposure of both animals and humans to prolonged iodine disinfectant is potentially harmful.     

Increased bone remodelling around titanium implants coated with chondroitin sulfate in ovariectomized rats

Coating titanium implants with artificial extracellular matrices based on collagen and chondroitin sulfate (CS) has been shown to enhance bone remodelling and de novo bone formation in vivo. The aim of this study was to evaluate the effect of estrogen deficiency and hormone replacement therapy (HRT) on the osseointegration of CS-modified Ti implants. 30 adult female, ovariectomized Wistar rats were fed either with an ethinyl-estradiol-rich diet (E) to simulate a clinical relevant HRT or with a genistein-rich diet (G) to test an alternative therapy based on nutritionally relevant phytoestrogens. Controls (C) received an estrogen-free diet. Uncoated titanium pins (Ti) or pins coated with type-I collagen and CS (Ti/CS) were inserted 8 weeks after ovarectomy into the tibia. Specimens were retrieved 28 days after implantation. Both the amount of newly formed bone and the affinity index (P < 0.05) were moderately higher around Ti/CS implants as compared to uncoated Ti. The highest values were measured in the G-Ti/CS and E-Ti/CS groups, the lowest values for the E-Ti and G-Ti controls. Quantitative synchrotron radiation micro-computed tomography (SRμCT) revealed the highest increase in total bone formation around G-Ti/CS as compared to C-Ti (P < 0.01). The effects with respect to direct bone apposition were less pronounced with SRμCT. Using scanning nanoindentation, both the indentation modulus and the hardness of the newly formed bone were highest in the E-Ti/CS, G-Ti/CS and G-Ti groups as compared to C-Ti (P < 0.05). Coatings with collagen and CS appear to improve both the quantity and quality of bone formed around Ti implants in ovarectomized rats. A simultaneous ethinyl estradiol- and genistein-rich diet seems to enhance these effects.