Testosterone alters duodenal calcium transport and longitudinal bone growth rate in parallel in the male rat.

Duodenal active calcium transport and longitudinal bone growth rate have been shown previously to be regulated in parallel by alteration of gonadal hormone status in sexually maturing female rats. The present study was designed to extend these observations to the sexually maturing male rat. Male rats were orchidectomized (ORX) and given Silastic implants containing either testosterone or estradiol at 6 weeks of age. At 9 weeks of age, duodenal active calcium transport was measured by the everted gut sac method and longitudinal bone growth rate was determined by tetracycline labeling. Decreases in body weight, longitudinal bone growth rate, duodenal calcium transport, and serum Ca and P were exhibited by ORX animals as compared with age-matched control animals. Testosterone administration to ORX animals resulted in an increase in body weight, longitudinal bone growth rate, duodenal calcium transport, and serum Ca and P as compared with ORX animals to a level not significantly different from that of age-matched control animals. Estradiol administration to ORX animals resulted in an additional decrease in body weight, although no significant effect on duodenal calcium transport, serum Ca, or P was noted as compared with ORX animals. There were no statistically significant alterations in the circulating levels of 1,25-dihydroxyvitamin D, parathyroid hormone, or osteocalcin in response to any of the experimental manipulations of gonadal status. These results indicate that, as in the female, gonadal hormone status affects intestinal calcium transport in sexually maturing male rats in parallel with changes in bone growth rate by mechanisms that are independent of circulating levels of 1,25-dihydroxyvitamin D.     

Effect of increased dietary calcium on body weight, food and water intake in oral contraceptive treated female rats

The effects of high calcium diet on body weight in OC treated rats are unknown. This study therefore investigated the effect of increasing dietary calcium from 0.9% to 2.5% on body weight, food ingestion, water intake, heart weight index and renal weight index in female Sprague-Dawley rats treated with a combination of OC steroids (ethinyloestradiol + norgestrel). The rats were assigned into three groups of average of 11 rats each; control, OC-treated and OC + Calcium – treated groups and administered orally for 10 weeks. Food and water intake, body weight, cardiac weight index, left ventricular weight index, renal weight index and serum calcium level were determined. The result shows that OC treated rats had significantly lower serum calcium concentration, body weight gain, food, water and calcium intake than those of the control rats. The OC + Calcium – treated rat had significantly higher serum calcium concentration, food, water and calcium intake but significantly lower body weight than those of the OC - treated rats. OC + Calcium - treated rats had significantly higher water intake, calcium intake and significantly lower body weight and food intake when compared with the control rats. Cardiac weight index and renal weight index was comparable in all groups. In conclusion, combined OC-induced reduction in weight gain might be associated with inhibition of the feeding center and consequent inhibition of the thirst center. Co-administration of dietary calcium augmented the reduction in weight gain seen in OC-treated rats probably by further suppression of the feeding and thirst centers.     

Fructose-induced hepatic gluconeogenesis: effect of L-carnitine

High fructose feeding (60 g/100 g diet) in rodents induces alterations in both glucose and lipid metabolism. The present study was aimed to evaluate whether intraperitoneal carnitine (CA), a transporter of fatty acyl-CoA into the mitochondria, could attenuate derangements in carbohydrate metabolizing enzymes and glucose overproduction in high fructose-diet fed rats. Male Wistar rats of body weight 150-160 g were divided into 4 groups of 6 rats each. Groups 1 and 4 animals received control diet while the groups 2 and 3 rats received high fructose-diet. Groups 3 and 4 animals were treated with CA (300 mg/Kg body weight/day, i.p.) for 30 days. At the end of the experimental period, levels of carnitine, glucose, insulin, lactate, pyruvate, glycerol, triglycerides and free fatty acids in plasma were determined. The activities of carbohydrate metabolizing enzymes and glycogen content in liver and muscle were assayed. Hepatocytes isolated from liver were studied for the gluconeogenic activity in the presence of substrates such as pyruvate, lactate, glycerol, fructose and alanine. Fructose-diet fed animals showed alterations in glucose metabolizing enzymes, increased circulating levels of gluconeogenic substrates and depletion of glycogen in liver and muscle. There was increased glucose output from hepatocytes of animals fed fructose-diet alone with all the gluconeogenic substrates. The abnormalities associated with fructose feeding such as increased gluconeogenesis, reduced glycogen content and other parameters were brought back to near normal levels by CA. Hepatocytes from these animals showed significant inhibition of glucose production from pyruvate (74.3%), lactate (65.4%), glycerol (69.6%), fructose (56.2%) and alanine (63.6%) as compared to CA untreated fructose-fed animals. The benefits observed could be attributed to the effect of CA on fatty acyl-CoA transport.     

Different Diabetogenic Response to Moderate Doses of Streptozotocin in Pregnant Rats,and Its Long-Term Consequences in the Offspring

Diabetes during pregnancy results in congenital malformations and long-term postnatal diseases. Experimental models are still needed to investigate the mechanism responsible for these alterations. Thus, by the administration of different doses of streptozotocin (STZ) (0, 25, 30, or 35 mg/kg body weight, intravenous) at the onset of pregnancy in rats, the present study sought an appropriate animal model for this pathology. At day 6 of pregnancy, plasma glucose was progressively higher with an increasing STZ dose, and in rats receiving the 35-mg dose, 2 subgroups were detected: some animals had plasma glucose levels above controls but below 200 mg/dL (mildly diabetic, MD), whereas others had levels above 400 mg/dL (severely diabetic, SD). At day 20 of pregnancy, the MD rats had normal glycemia, but after an oral glucose load (2 g/kg body weight), plasma glucose increased more and insulin increased less than in controls. The SD rats maintained their hyperglycemia and had a greatly impaired oral glucose tolerance. At day 20, fetuses of SD dams were fewer, weighed less, and had enhanced plasma glucose and triglycerides and decreased insulin, whereas those from MD dams did not differ from controls. At birth, newborns from MD dams had higher body weight, plasma insulin, and liver triglycerides as well as total body lipid concentrations than controls, and on day 21, remained macrosomic and showed higher plasma glucose and liver triglyceride concentrations. At 70 days of age, offspring of MD dams had impaired oral glucose tolerance but normal plasma insulin change in the case of females, whereas plasma insulin increased less in males. These alterations were manifest more in those offspring from dams that had > 50% macrosomic newborns than in those from dams that had < 50% macrosomic newborns. In conclusion, whereas our MD rats mimic the changes taking place in gestational diabetic women and show the long-term risk of macrosomia, the SD rats are more similar to uncontrolled diabetics. Thus these two rat models, obtained with moderate amounts of STZ, could be used to study the pathophysiological consequences of these different diabetic conditions.     

Effect of dietary calcium on cadmium absorption and retention in suckling rats

The effect of calcium supplementation on absorption and retention of cadmium in the suckling period was evaluated in Wistar rat pups of both sexes. Animals were maintained in the litters with the mother rats and supplemented with 1%, 3% or 6% calcium (as CaHPO₄×2H₂O) in cow's milk by artificial feeding from day of birth 6 through 14. All rats were exposed to cadmium (as CdCl₂×H₂O) either orally or parenterally. Oral cadmium dose of 0.5 mg/kg body weight a day was administered through nine-day period of calcium supplementation and parenteral cadmium dose was injected subcutaneously in a single dose of 0.5 mg Cd/kg body weight prior to calcium supplementation. On experimental day 10 (at the age of pups of 15 days) all animals were killed and the liver, kidneys, brain and carcass (body without organs and skin) were removed for element analyses. Cadmium and essential elements calcium, zinc and iron were analysed in the tissues by atomic absorption spectrometry. Results showed that after oral exposure cadmium concentrations in all calcium-supplemented groups were significantly decreased in the organs and carcass and that the effect was dose-related. No such effect of calcium was found after parenteral cadmium exposure. Calcium supplementation per se significantly increased calcium concentration in the carcass and had no effect on iron in organs and zinc in carcass. It was concluded that calcium supplementation during the suckling period could be an efficient way of reducing oral cadmium absorption and retention without affecting tissue essential trace element concentrations.     

Combined Effects of Phytoestrogen Genistein and Silicon on Ovariectomy-Induced Bone Loss in Rat

This study was performed to evaluate the effect of concomitant supplementation of genistein and silicon on bone mineral density and bone metabolism-related markers in ovariectomized rat. Three-month-old Sprague Dawley female rats were subjected to bilateral ovariectomy (OVX) or sham surgery, and then the OVX rats were randomly divided into four groups: OVX-GEN, OVX-Si, OVX-GEN-Si, and OVX. Genistein and silicon supplementation was started immediately after OVX and continued for 10 weeks. In the OVX-GEN group, 5 mg genistein per gram body weight was injected subcutaneously. The OVX-Si group was given soluble silicon daily in demineralized water (Si 20 mg/kg body weight/day). The OVX-GEN-Si group was given subcutaneous injections of 5 mg genistein per gram body weight, at the same time, given soluble silicon daily (Si 20 mg/kg body weight/day). The results showed that the genistein supplementation in the OVX rats significantly prevented the loss of uterus weight; however, the silicon supplementation showed no effect on the uterus weight loss. The lumbar spine and femur bone mineral density was significantly decreased after OVX surgery; however, this decrease was inhibited by the genistein and/or silicon, and the BMD of the lumbar spine and femur was the highest in the OVX-GEN-Si-treated group. Histomorphometric analyses showed that the supplementation of genistein and/or silicon restored bone volume and trabecular thickness of femoral trabecular bone in the OVX group. Besides, the treatment with genistein and silicon for 10 weeks increased the serum levels of calcium and phosphorus in the OVX rats; serum calcium and serum phosphorus in the OVX-GEN-Si group were higher than those in the OVX-GEN and OVX-Si group (P < 0.05). At the same time, the treatment with genistein and/or silicon decreased serum alkaline phosphatase (ALP) and osteocalcin, which were increased by ovariectomy; serum ALP and osteocalcin in the OVX-GEN-Si group were lower than those in the OVX-GEN and OVX-Si groups (P < 0.05). The results above indicate that genistein and silicon have synergistic effects on bone formation in ovariectomized rats.     

Effects of vitamin D supplementation on calcium balance and bone growth in young rats fed normal or low calcium diet

OBJECTIVE: We examined the effect of vitamin D supplementation on bone growth in young rats fed a normal or low calcium diet. METHODS: Fifty female Sprague-Dawley rats, 6 weeks of age, were randomized by stratified weight method into five groups with 10 rats in each group: baseline control, 0.5% (normal) or 0.1% (low) calcium diet, and 0.5 or 0.1% calcium diet + vitamin D (25 microg/100 g, food intake). Duration of the experiment was 10 weeks. RESULTS: Vitamin D supplementation stimulated intestinal calcium absorption and increased urinary calcium excretion in rats fed a low or normal calcium diet. Vitamin D supplementation prevented the reduction in periosteal bone gain but enhanced enlargement of the marrow cavity and reduced the maturation-related cancellous bone gain in rats fed a low calcium diet, and increased the maturation-related cancellous and cortical bone gains in rats fed a normal calcium diet. CONCLUSION: This study shows the differential effects of vitamin D supplementation on born growth in young rats fed a normal or low calcium diet.     

Moringa peregrina leaf extracts produce anti-obesity,hypoglycemic, anti-hyperlipidemic,and hepatoprotective effects on high-fat diet fed rats

This present research investigated the anti-obesity and hepatoprotective effects of ethanolic Moringa peregrina leaf (MPLE) and bark extracts (MPBE), in the rats fed with a high-fat diet (HFD). Healthy male rats (n = 48) were randomly distributed to six groups (n = 8): control AIN-93 diet; HFD; HFD + MPBE bark extracts ((300 mg/kg); HFD + MPBE (600 mg/kg); HFD + MPLE (300 mg/kg); HFD + MPLE (600 mg/kg). HFD-fed rats in the Moringa peregrina (MP) treatment groups received orally administered MP leaf or bark extract daily for eight weeks. The results revealed that both doses of MP leaf extract significantly reduced HFD-induced increases in their food intake and the gained body weight, fat pad weights (visceral, subcutaneous, and epididymal), glucose and insulin plasma levels, and leptin and resistin serum levels in HFD-fed rats. Concomitantly, MP leaf extract improved glucose levels after oral or intraperitoneal glucose tolerance tests, reduced serum cholesterol, triglycerides, and the low-density lipoprotein LDL concentration, reduced hepatic triglycerides and cholesterol levels, and increased serum high-density lipoproteins HDL levels and triglycerides and cholesterol levels in fecal. Moreover, the administration of MPLE to HFD-fed rats improved liver architecture, reduced fat accumulation, reduced hepatic malondialdehyde, tumor necrosis factor-α, and interleukin-6 levels. Hepatic glutathione peroxidase, superoxide dismutase, and catalase activities were significantly increased. All observed effects were more pronounced in HFD-fed rats treated with a 600 mg/kg MP dose. However, neither dose of MPBE altered the measured markers in the HFD-fed rats. In conclusion, MPLE showed potential anti-obesity and hepatoprotective activity in HFD-induced obese rats, mediated by reduced lipid absorption, anti-hyperlipidemic effects, and hepatic antioxidant effects.     

Super CitriMax (HCA-SX) attenuates increases in oxidative stress, inflammation, insulin resistance, and body weight in developing obese Zucker rats

Super CitriMax (HCA-SX) is a novel calcium/potassium salt of (−)-hydroxycitric acid extracted from the dried fruit rind of the plant Garcinia cambogia, and commonly consumed as weight loss dietary supplement. In the present study, we investigated the effect of HCA-SX on inflammation, oxidative stress and insulin resistance in developing obese Zucker rats, an animal model of type II diabetes associated with inflammation and oxidative stress. Male Zucker rats (5-week old) were supplemented with vehicle (control) and HCA-SX in drinking water for 7 weeks. Oxidative stress markers, including malondialdehyde (MDA), protein carbonyl (DNPH), and protein tyrosine nitration (tyr-NO₂) were measured in the liver and kidney tissues using biochemical and immunoblotting techniques. Compared to controls, the levels of MDA, DNPH and tyr-NO₂ were lower in the liver and kidney of HCA-SX-treated animals. Furthermore, the levels of C-reactive protein and interleukin-6, markers of inflammation measured by ELISA, were lower in the plasma of HCA-SX-supplemented animals compared to controls, as were levels of fasting plasma insulin, glucose, and triglycerides. Interestingly, insulin resistance did not develop in HCA-SX-supplemented rats. Food-intake and body weight gain was also lower in rats supplemented with HCA-SX compared to their control counterparts. These results suggest that HCA-SX supplementation in obese Zucker rats reduces food-intake, body weight gain, and also attenuates the increases in inflammation, oxidative stress, and insulin resistance observed in untreated animals. Therefore, HCA-SX may be used as an intervention to overcome obesity-related complications, including inflammation, oxidative stress, and insulin resistance.     

Short-term Administration of Water-soluble Silicon Improves Mineral Density of the Femur and Tibia in Ovariectomized Rats

Silicon is important for the proper growth and development of bone and connective tissues. This study was designed to investigate if water-soluble silicon could be used for the treatment of postmenopausal osteoporosis. Silicon (Si 20 mg/kg body weight/day) was administrated orally to 17-week-old ovariectomized (OVX) rats for 4 weeks. Silicon did not alter weight gain in OVX rats. Silicon supplementation significantly increased the bone mineral density of the femur (p < 0.05, vs. OVX control group) and tibia in OVX rats (p < 0.05, vs. OVX control group). Serum alkaline phosphatase and osteocalcin, two bone formation biomarkers tested, were not significantly altered, but urinary calcium and phosphorous excretion tended to decrease with silicon supplementation. OVX rats with silicon supplementation showed a relatively higher serum CTx compared to the nonsupplemented OVX group (p < 0.01, vs. OVX control group). According to these results, short-term soluble silicon supplementation improved bone mineral density in OVX-induced osteoporosis.     

Antiosteoporotic activity of icariin in ovariectomized rats

Icariin was evaluated for its antiosteoporotic activity in an ovariectomized rat model of osteoporosis. The rats were divided into sham and OVX groups. The OVX rats were then subdivided into five groups treated with water, nylestriol (1 mg/kg body weight, weekly, orally) or icariin (ICA) (5, 25, and 125 mg/kg body weight, daily, orally) for 12 weeks. In OVX rats, the increases of body weight, serum BGP and ALP were significantly decreased by ICA treatment. In OVX rats, atrophy of uterus and descent of BMD were suppressed by treatment with ICA. In addition, ICA (125 mg/kg body weight) completely corrected the decreased serum concentration of Calcium, Phosphorus, and E₂ observed in OVX rats. ICA (125 mg/kg body weight) increased biomechanical strength significantly in comparison to the sham group. Histological results also showed its protective action through promotion of bone formation. The findings, assessed on the basis of biochemical, bone mineral density, biomechanical, and histopathological parameters, showed that ICA has a definite antiosteoporotic effect, similar to estrogen, especially effective for prevention bone fracture induced by estrogen deficiency.     

Comparison of verapamil and felodipine treatment on lipid and glucose metabolism in obese female SHHF/Mcc-facp rats.

Calcium channel blockers, verapamil or felodipine, were given to genetically obese 6 and 11-month-old female SHHF/Mcc-facp (SHHF: Spontaneous Hypertension Heart Failure) rats for 8 weeks to investigate their effects on glucose and lipid metabolism and obesity. Both antihypertensive agents significantly decreased systolic blood pressure. In 11-month-old rats, verapamil treatment significantly decreased body weight after 4 weeks whereas with felodipine it was only significantly reduced after 8 weeks. In 6-month-old rats, verapamil significantly curtailed body weight gain. Subcutaneous fat depots were smaller, and abdominal fat depots were larger in verapamil rats compared to felodipine or control rats. Oral glucose tolerance tests in the 6-month-old verapamil and the 11-month-old felodipine groups showed improved glucose tolerance compared to their respective control groups. After 8 weeks of treatment, fasting plasma glucose levels were lower in 6-month-old verapamil rats compared to felodipine and control rats and were decreased by both verapamil and felodipine treatments as compared to control in 11-month-old rats. During the oral glucose tolerance test in 6-month-old rats, both fasting plasma insulin and the area under the insulin curve were increased in verapamil compared to both control and felodipine groups. When compared to controls, plasma cholesterol was increased by verapamil in both age groups, but was significantly decreased by felodipine after 8 weeks of treatment in the 11-month-old group. Plasma triglycerides increased in all control rats compared to initial levels; however, verapamil and felodipine groups showed lower triglycerides in both age groups. In 6-month-old rats, the percentages of plasma HDL significantly increased in both treatment groups as compared to control. This study shows that verapamil and felodipine depressed body weight gain in the young rats, reduced body weight in the old rats, improved lipid parameters and glucose tolerance, but had the opposite effects on body fat distribution and insulin levels in obese female SHHF rats.     

Silicon Supplementation Improves the Bone Mineral Density of Calcium-Deficient Ovariectomized Rats by Reducing Bone Resorption

The purpose of this study was to investigate the effect of silicon (Si) supplementation on bone mineral density (BMD) and bone metabolism parameters relative to calcium (Ca) intake levels in ovariectomized rats. A total of 72 female Wistar rats (6 weeks) were ovariectomized (OVX) and divided into six groups, and Si (500 mg of Si per kilogram of feed) was or was not administered with diets containing various levels of Ca (0.1%, 0.5%, and 1.5%) for 10 weeks. The groups were as follows: (1) Ca-deficient group (0.1% Ca), (2) Ca-deficient with Si supplementation group, (3) adequate Ca group (0.5% Ca), (4) adequate Ca with Si supplementation group, (5) high Ca group (1.5% Ca), and (6) high Ca with Si supplementation group. Si supplementation significantly increased the BMD of the femur and tibia in Ca-deficient OVX rats, while no change was observed with Si supplementation in the BMD of the spine, femur, and tibia in the adequate and high Ca groups. Serum alkaline phosphatase and osteocalcin levels were not affected by Si supplementation or Ca intake levels. C-telopeptide type I collagen levels were significantly decreased as a result of Si supplementation in Ca-deficient OVX rats. In summary, Si supplementation produced positive effects on bone mineral density in Ca-deficient OVX rats by reducing bone resorption. Therefore, Si supplementation may also prove to be helpful in preventing osteoporosis in postmenopausal women whose calcium intake is insufficient.     

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.     

Influences of crude extract of tea leaves,Camellia sinensis,on streptozotocin diabetic male albino mice

Natural remedies from medicinal plants are considered to be effective and safe alternative treatment for diabetes mellitus. The aim of the present study was to investigate the hypoglycemic activity of the crude tea leaves extract on streptozotocin (STZ)-induced diabetic mice. The average body weight of animals with diabetes and their percentage changes of body weight gain after 15 and 30 days were significantly lower than that of the normal control mice. In diabetic mice, supplementation with tea leaves extract decreased the loss of body weight. After 15 and 30 days, significant increases in the levels of serum glucose, triglycerides, cholesterol, creatinine, urea, uric acid, glutamic pyruvic acid transaminase (GPT) and glutamic oxaloacetic acid transaminase (GOT) were noted in STZ-diabetic mice fed with normal diet. Also, the values of total protein in this group were statistically declined after 15 and 30 days. The levels of serum glucose and GPT were significantly elevated after 15 and 30 days in diabetic mice supplemented with tea leaves extract. Moreover, the level of serum GOT was notably increased after 30 days. Insignificant alterations were observed in the levels of serum triglycerides, cholesterol, total protein, creatinine, urea and uric acid in diabetic mice supplemented with tea leaves extract. Thus, the present results have shown that tea leaves extract has the antihyperglycemic, antihyperlipidemic, and antihyperproteinemic effects and consequently may alleviate liver and kidney damage associated with STZ-induced diabetes in mice.     

Metabolomic studies on the biochemical profile of urine from rats with acute cysteamine supplementation

This study investigates the effect of acute cysteamine (CS) supplementation on rat metabolism. A metabolomic strategy using high-resolution ¹H-NMR spectroscopy in conjunction with principal component analysis was applied to examine rat biological responses to CS administration. Half of female Sprague–Dawley rats (2 groups of 6 rats) were each given doses of 150 mg CS/kg body weight intraperitoneally. Urine samples were collected twice daily (0–8 and 8–24 h) from the rats following CS administration. The identifiable biochemical effects associated with CS supplementation included decreased urinary concentrations of hippurate, succinate, citric acid, and 2-oxoglutarate, as well as increased urinary concentrations of dimethylamine, dimethylglycine, glycine, and taurine. These effects were predominately seen within the first 8 h after CS administration. Clear differences in succinate, citric acid, and 2-oxoglutarate were observed 8–24 h following CS. The results suggest that CS supplementation in the rats resulted in modulation of intestinal microbial metabolism and metabolic perturbation of the tricarboxylic acid cycle.     

Black and green tea improves lipid profile and lipid peroxidation parameters in Wistar rats fed a high-cholesterol diet

In the present study, the efficacy of black tea (BT) and green tea (GT) was studied in relation to serum and hepatic oxidative abnormalities in hypercholesterolemic rats. Hypercholesterolemia was induced in male Wistar rats (8 week old) by feeding them with a high-cholesterol diet (HCD) for 35 days. The experimental rats were given BT and GT as a supplement (7 g/L) via drinking water. Increased hepatic and serum lipid profile along with abnormalities in oxidative marker, with a concomitant increase in the body weight, food intake, and food efficiency, were seen in hypercholesterolemic rats. Following the supplementation of BT and GT to rats fed with HCD, significantly lower levels of serum and hepatic cholesterol, triglycerides, serum low-density lipoprotein cholesterol, and increased high-density lipoprotein cholesterol levels were observed, when compared with hypercholesterolemic group. Further, significantly lower levels in the serum and hepatic lipid peroxidation, body weight gain, and food efficiency were observed in BT and GT group when compared with control and HCD fed group. However, no such significant changes were observed in the food intake upon supplementation with BT and GT. These results suggest that supplementation of BT and GT may protect against the serum and hepatic abnormalities in hypercholesterolemic rats.     

Xanthohumol lowers body weight and fasting plasma glucose in obese male Zucker fa/fa rats

Obesity contributes to increased risk for several chronic diseases including cardiovascular disease and type 2 diabetes. Xanthohumol, a prenylated flavonoid from hops (Humulus lupulus), was tested for efficacy on biomarkers of metabolic syndrome in 4 week old Zucker fa/fa rats, a rodent model of obesity. Rats received daily oral doses of xanthohumol at 0, 1.86, 5.64, and 16.9 mg/kg BW for 6 weeks. All rats were maintained on a high fat (60% kcal) AIN-93G diet for 3 weeks to induce severe obesity followed by a normal AIN-93G (15% kcal fat) diet for the last 3 weeks of the study. Weekly food intake and body weight were recorded. Plasma cholesterol, glucose, insulin, triglyceride, and monocyte chemoattractant protein-1 (MCP-1) levels were assessed using commercial assay kits. Plasma and liver tissue levels of XN and its metabolites were determined by liquid–chromatography tandem mass spectrometry. Plasma and liver tissue levels of xanthohumol were similar between low and medium dose groups and significantly (p < 0.05) elevated in the highest dose group. There was a dose-dependent effect on body weight and plasma glucose levels. The highest dose group (n = 6) had significantly lower plasma glucose levels compared to the control group (n = 6) in male but not female rats. There was also a significant decrease in body weight for male rats in the highest dose group (16.9 mg/kg BW) compared to rats that received no xanthohumol, which was also not seen for female rats. Plasma cholesterol, insulin, triglycerides, and MCP-1 as well as food intake were not affected by treatment. The findings suggest that xanthohumol has beneficial effects on markers of metabolic syndrome.     

Effect of endrin on the hepatic distribution of iron and calcium in female Sprague-Dawley rats.

The distribution of iron and calcium in hepatic subcellular fractions of female rats treated with endrin (1,2,3,4,10,10-hexachloro-6,7-epoxy-1,4,4 alpha,5,6,7,8,8 alpha- octahydroendo,endo-1,4:5,8-dimethanonaphthalene) was determined. Endrin in corn oil was administered orally to rats in single doses of 3, 4.5, or 6 mg/kg, and the animals were killed at 0, 12, 24, 48, or 72 hr post-treatment. Iron and calcium were determined by atomic absorption spectroscopy. The administration of endrin increased the iron content of mitochondria and decreased the iron content of microsomes and nuclei. Significant increases occurred in the calcium content of mitochondria, microsomes, and nuclei. Thus, the results indicate that with respect to the subcellular distribution of iron and calcium, endrin produces differential effects. Vitamin E succinate administration partially prevented the endrin-induced hepatic alterations in iron and calcium homeostasis. Endrin also produced dose- and time-dependent increases in the liver and spleen weight/body weight ratios, while decreasing the thymus weight/body weight ratios. The altered distribution of calcium and iron may contribute to the broad range of effects of endrin.     

Diet-induced insulin resistance precedes other aspects of the metabolic syndrome

This study wasdesigned to examine the effects of a high-fat refined-sugar (HFS) or alow-fat complex-carbohydrate (LFCC) diet on insulin-stimulated skeletalmuscle glucose transport, plasma insulin, blood pressure, plasmatriglycerides, plasma glycerol, body weight, and body fat in femaleFischer rats. Insulin-stimulated glucose transport was significantlyreduced in the HFS group at 2 wk, 2 mo, and 2 yr, whereas serum insulinwas significantly elevated at all time points. Blood pressure was notsignificantly elevated in the HFS group until 12 mo, and all HFSanimals were hypertensive by 18 mo. Glycerol, triglycerides, andabdominal fat cell size were not significantly different at 2 wk butwere significantly elevated in the HFS rats at 2 and 6 mo. Body weight was similar in both groups until 20 wk on the diet, when the HFS ratsstarted to gain more weight. These results demonstrate that insulinresistance and hyperinsulinemia occur before the other manifestationsof the metabolic syndrome and that diet, not obesity, is the underlyingcause.