Dietary magnesium supplementation affects bone metabolism and dynamic strength of bone in ovariectomized rats

We evaluated the effect of magnesium supplementation on apparent calcium absorption, bone metabolism and dynamic bone strength in ovariectomized (OVX) rats as a model of postmenopausal women. Two groups of OVX rats were fed a 0.05% Mg diet or a 0.15% Mg diet, and one group of sham-operated rats was fed the 0.05% Mg diet for 42 d. We collected feces and urine of all rats for 3-d periods starting from d 3, 10, 17, 24, 31 and 38 of the feeding experiment for calcium and magnesium balance studies. Urine was collected for 24 h from d 41 of the feeding experiment for measuring deoxypyridinoline. After the 42 d, the rats were killed, serum prepared and femora excised. The apparent calcium absorption in the OVX rats fed 0.15% Mg was significantly lower than both other groups. Additionally, the urinary excretion of deoxypyridinoline (a bone resorption marker) and the serum parathyroid hormone level of the OVX rats fed the 0.15% Mg diet were significantly lower than in the OVX rats fed 0.05% Mg. Serum osteocalcin (a bone formation marker) in the OVX rats fed the 0.15% Mg diet was significantly higher than in the OVX rats fed 0.05% Mg. The breaking force and breaking energy of the femur in the OVX rats fed the 0.15% Mg diet were significantly higher than in the OVX rats fed the 0.05% Mg diet. These results indicate that magnesium supplementation reduces apparent calcium absorption, but promotes bone formation and prevents bone resorption in OVX rats. Moreover, our results indicate magnesium supplementation increases the dynamic strength of bone.     

Hesperidin,a citrus flavonoid,inhibits bone loss and decreases serum and hepatic lipids in ovariectomized mice

The purpose of this study was to examine whether hesperidin inhibits bone loss in ovariectomized mice (OVX), an animal model of postmenopausal osteoporosis. Forty 8-wk-old female ddY mice were assigned to five groups: a sham-operated group fed the control diet (AIN-93G), an OVX group fed the control diet, an OVX+HesA group fed the control diet containing 0.5 g/100 g hesperidin, and an OVX+HesB group fed the control diet containing 0.7 g/100 g alpha-glucosylhesperidin and an OVX+17beta-estradiol (E(2)) group fed the control diet and administered 0.03 micro g E(2)/d with a mini-osmotic pump. After 4 wk, the mice were killed and blood, femoral, uterine and liver were sampled immediately. Hesperidin administration did not affect the uterine weight. In OVX mice, the bone mineral density of the femur was lower than in the sham group (P < 0.05) and this bone loss was significantly prevented by dietary hesperidin or alpha-glucosylhesperidin. The Ca, P and Zn concentrations in the femur were significantly higher in the hesperidin-fed and E(2) groups than in the OVX group. Histomorphometric analyses showed that the trabecular bone volume and trabecular thickness in the femoral distal metaphysis were markedly decreased (P < 0.05) by OVX, and alpha-glucosylhesperidin significantly prevented this bone loss. Furthermore, hesperidin decreased the osteoclast number of the femoral metaphysis in OVX mice, as did E(2). Serum and hepatic lipids were lower in mice that consumed the hesperidin-containing diets (P < 0.05) than in the OVX group fed the control diet. These results suggest a possible role for citrus flavonoids in the prevention of lifestyle-related diseases because of their beneficial effects on bone and lipids.     

Effects of daidzein and kiwifruit on bone mineral density and equol production in ovariectomised rats

In this study, we investigated the synergistic effects of daidzein (Dz) and kiwifruit on bone and equol production in ovariectomised (OVX) rats. Female Sprague-Dawley rats were randomly assigned to one of five groups: sham operated, OVX control, OVX fed 0.1% Dz-supplemented diet (OVX?+?Dz), OVX fed 0.1% Dz and green kiwifruit (GRK)-supplemented diet (OVX?+?Dz?+?GRK) and OVX fed 0.1% Dz and gold kiwifruit (GOK)-supplemented diet (OVX?+?Dz?+?GOK). There were no significant differences in whole body and femur bone mineral density (BMD) among groups at week 8. BMD in the OVX group significantly decreased at week 8; however, BMD in the OVX?+?Dz?+?GRK was not significantly different from baseline in the end of the study. However, supplementation with kiwifruit did not affect urinary equol concentrations, urinary ratios of equol to Dz and the composition of caecal microbiota. These results suggest that the combination of Dz and GRK may slightly reduce bone loss caused by oestrogen deficiency but does not affect equol production.     

Consumption of legumes improves certain bone markers in ovariectomized rats

Soybeans are known to protect against osteoporosis, but other legumes frequently consumed in Asia have not been studied to learn if they have a similar protective effect. This study investigated the hypothesis that consumption of soybean, mung bean, cowpea, and adzuki bean has beneficial effects on bone biomarkers in ovariectomized rats. Female Sprague-Dawley rats were either sham operated (sham; n = 7) or surgically ovariectomized and then fed a regular AIN-93M diet (OVX; n = 7) or AIN-93M containing soybean (n = 7), mung bean (n = 7), cowpea (n = 7), or adzuki beans (n = 7) for 10 weeks. No bean consumption significantly altered the body, subcutaneous fat, or uterus weight; however, consumption significantly increased the serum calcium/phosphorous ratio and decreased urinary calcium excretion compared with those of the OVX group. Serum concentration of 17β-estradiol was significantly lower in the OVX group compared with that of the sham group and was lowest in the group fed OVX diet containing soybean. Serum osteocalcin concentration was significantly higher in all OVX rats given a diet with beans compared with the same diet without, but urinary deoxypyridinoline excretion was lowest in the group fed OVX diet containing cowpea. There were no significant differences in bone mineral density or bone mineral content of the right femur, tibia, or lumbar spine or in the trabecular bone volume of the tibia among the diet groups. In conclusion, the consumption of soybean, mung bean, cowpea, and adzuki bean in OVX rats improved osteocalcin, but only those fed cowpea showed decreased bone resorption biomarker, suggesting that cowpea may have the most protective effect on bone in OVX rats.     

Effects of taurine supplementation on bone mineral density in ovariectomized rats fed calcium deficient diet

Taurine supplementation has been shown to have a beneficial effect on femur bone mineral content in ovariectomized rats. It therefore seemed desirable to find out whether the beneficial effect of taurine on ovariectomized rats fed calcium deficient diet could also be reproduced. Forty female Sprague-Dawley rats were divided into two groups. One group was OVX and the other group received sham operation (SHAM), and received either control diet or a taurine supplemented diet for 6 weeks. All rats were fed on calcium deficient diet (AIN-93: 50% level of calcium) and deionized water. Bone mineral density (BMD) and bone mineral content (BMC) were measured in spine and femur. The serum and urine concentrations of calcium and phosphorus were determined. Bone formation was measured by serum osteocalcin and alkaline phosphatase (ALP) concentrations. Bone resorption rate was measured by deoxypyridinoline (DPD) crosslinks immunoassay and corrected for creatinine. Urinary calcium and phosphorus excretion, osteocalcin in blood and cross link value were not significantly different among the groups. Within the OVX group, the taurine supplemented group had not higher femur bone mineral content than the control group. This study established the need for a study on the taurine effect on bone with different calcium levels.     

Effect of dietary legumes on bone-specific gene expression in ovariectomized rats

In previous studies, we found that the consumption of legumes decreased bone turnover in ovariectomized rats. The purpose of the present study is to determine whether the protective effects on bone mineral density (BMD) and the microarchitecture of a diet containing legumes are comparable. In addition, we aim to determine their protective actions in bones by studying bone specific gene expression. Forty-two Sprague-Dawley rats are being divided into six groups during the 12 week study: 1) rats that underwent sham operations (Sham), 2) ovariectomized rats fed an AIN-93M diet (OVX), 3) ovariectomized rats fed an AIN-93M diet with soybeans (OVX-S), 4) ovariectomized rats fed an AIN-93M diet with mung beans (OVX-M), 5) ovariectomized rats fed an AIN-93M diet with cowpeas (OVX-C), and 6) ovariectomized rats fed an AIN-93M diet with azuki beans (OVX-A). Consumption of legumes significantly increased BMD of the spine and femur and bone volume of the femur compared to the OVX. Serum calcium and phosphate ratio, osteocalcin, expression of osteoprotegerin (OPG), and the receptor activator of nuclear factor κB ligand (RANKL) ratio increased significantly, while urinary excretion of calcium and deoxypyridinoline and expression of TNF-α and IL-6 were significantly reduced in OVX rats fed legumes, compared to OVX rats that were not fed legumes. This study demonstrates that consumption of legumes has a beneficial effect on bone through modulation of OPG and RANKL expression in ovariectomized rats and that legume consumption can help compensate for an estrogen-deficiency by preventing bone loss induced by ovarian hormone deficiency.     

Diets containing blueberry extract lower blood pressure in spontaneously hypertensive stroke-prone rats

Oxidative stress in the vasculature and kidneys contributes to hypertension, a major risk factor for cardiovascular disease. Blueberries (BB) are rich in antioxidants, and so we hypothesized that feeding diets enriched with BB would slow the development of hypertension in spontaneously hypertensive stroke-prone rats (SHRSP). Eight-week-old normotensive rats and SHRSP were fed either a control diet (Con) or a diet enriched with 3% freeze-dried BB for 8 weeks. Systolic blood pressure (SBP) was measured at weeks 2, 4, 6, 7, and 8 by the tail cuff method, and urine was collected at weeks 4 and 8. The SBP was elevated in SHRSP relative to normotensive rats over the entire 8-week feeding period. In SHRSP consuming BB, SBP was 19% lower at week 4 and 30% lower at week 6, relative to SHRSP on Con. Maximum SBP was 216 ± 11 mm Hg in SHRSP consuming Con vs 178 ± 15 mm Hg in the BB-fed group (P = .036). Spontaneously hypertensive stroke-prone rats had elevated levels of urine F2-isoprostanes/creatinine relative to normotensive rats, indicating systemic oxidative stress in this strain. Blueberry feeding had no effect on urinary excretion of F2-isoprostanes; therefore, it is unlikely that a systemic antioxidant effect of BB is responsible for the antihypertensive effects at weeks 4 and 6. Blueberry-fed rats had reduced markers of renal oxidative stress, such as proteinuria and kidney nitrites. Thus, a 3% BB diet may be capable of protecting the kidneys from oxidative damage in SHRSP, thereby reducing the magnitude of hypertension.     

Effects of trans-resveratrol from Polygonum cuspidatum on bone loss using the ovariectomized rat model

trans-Resveratrol (resveratrol) has been shown in several studies to significantly modulate biomarkers of bone metabolism. But, there is no direct evidence supporting its inhibitory effect towards bone loss. In the present study, effects of resveratrol on bone mineral density (BMD) and bone calcium content (BCC) were examined in the ovariectomized (OVX) rat model. Female Wistar rats were divided into four groups: SHAM group (sham-operated), OVX group (OVX control), OVX + ALD group (OVX and treated with 1.0 mg/kg of body weight of alendronate sodium), and OVX + RES group (OVX and treated with 0.7 mg/kg of body weight of resveratrol). Tested materials were given by gavage for 12 weeks after ovariectomy. Results showed that rats in the OVX, OVX + ALD, and OVX + RES groups had significantly higher body weights and feed efficiency than those in the SHAM group (P < .01). The OVX group had significantly lower femoral epiphysis BMD than the SHAM group, and epiphysis BMD in the OVX + ALD and OVX + RES groups was significantly greater than that in the OVX group (P < .05). However, the femoral midpoint BMD was not significantly different among the four groups. Additionally, animals in the OVX group had significantly lower BCC compared with the SHAM group, while the BCC of the OVX + ALD and OVX + RES groups was significantly higher than that of the OVX group (P < .05). These results indicated that resveratrol could increase epiphysis BMD and inhibit the decrease of femur BCC in OVX rats, suggesting that it could play a role in protecting against bone loss induced by estrogen deficiency.     

Effects of dietary taurine supplementation on plasma and liver lipids in OVX rats fed calcium-deficient diet

Taurine supplementation has been shown to have an effect on lowering blood lipids in ovariectomized (OVX) rats. It therefore seemed desirable to find out whether the beneficial effect of taurine on OVX rats fed calcium-deficient diet could also be reproduced. Forty female Sprague-Dawley rats were divided into two groups. One group was OVX and the other group received a sham operation (Sham). Each rat group was further divided into the control diet and the taurine supplemented (2.0 g/100 g diet) diet group. All rats were fed on calcium-deficient diet and deionized water ad libitum for 6 weeks. Plasma and liver lipids were determined by using commercial kits. LDL-cholesterol concentrations were estimated with the equation of Friedewald et al. (1972). There were no significant differences in body weight gain and food intake between the control and taurine group within Sham and OVX groups, but body weight gain, food intake, and food efficiency ratio was higher in the OVX group. Concentrations of plasma total cholesterol, triglyceride, LDL-cholesterol were significantly lower in the taurine fed group of OVX rats fed Ca deficient diet, while HDL-cholesterol concentration was increased in the taurine fed group. Therefore, in this study, we examined whether taurine also prevented hypercholesterolemia induced by ovarian hormone deficiency in ovariectomized rats when they were fed a calcium-deficient diet. These results indicate that taurine may have some beneficial effects on hypercholesterolemia and hypertriglyceridemia in OVX rats fed calcium-deficient diet.     

Soybean isoflavones dose-dependently reduce bone turnover but do not reverse established osteopenia in adult ovariectomized rats

We assessed the dose-dependent effects of daily soybean isoflavone (IF) consumption in reversing bone loss in adult ovariectomized rats. On d 0, female Wistar rats (7 mo old; n = 55) were either sham-operated (SH; n = 14) or ovariectomized (n = 41). On d 80, intermediate rats (SH: n = 5; ovariectomized: n = 5) were killed to confirm the ovariectomy-induced bone loss. The remaining ovariectomized rats were randomly assigned to one of four groups of nine rats each and fed soybean IF (mixed with a soy protein-free semipurified diet) at 0 (OVX), 20 (IF20), 40 (IF40) or 80 (IF80) mg/(kg body. d) for 84 d. Simultaneously, SH rats were fed the semipurified diet without any additional compound and killed on d 164, as were the other rats. As expected, both bone mineral density in the total femur and in its diaphyseal and metaphyseal subregions and cancellous bone area/measured surface in the distal femur metaphysis were lower in OVX than in SH rats (P: < 0.05). OVX rats had higher plasma osteocalcin concentration and urinary deoxypyridinoline excretion than SH rats (P: < 0.05). On d 164, osteocalcin and deoxypyridinoline concentrations were lower in IF40 or IF80 rats than in OVX rats (P: < 0.05). Nevertheless, neither bone mineral density nor cancellous bone area was greater in IF-fed rats than in OVX rats. Therefore, in adult ovariectomized rats, daily soybean IF consumption decreased bone turnover but did not reverse established osteopenia.     

A combination of dietary fructooligosaccharides and isoflavone conjugates increases femoral bone mineral density and equol production in ovariectomized mice

Fructooligosaccharides (FOS) stimulate the growth of bifidobacteria, which cleave isoflavone conjugates to yield the corresponding aglycones and metabolites. In a previous study, FOS modified the absorption and enterohepatic recirculation of isoflavones in rats. In the present study, we determined the effect of the combination of dietary FOS and isoflavone conjugates on bone mass in ovariectomized (OVX) and surgical control mice. After undergoing OVX or sham operation, female ddY mice (8 wk old, n = 64) were randomly assigned to four groups: a purified control diet (AIN-93G) group, a FOS diet (AIN-93G + 5% FOS) group, an isoflavone diet (AIN-93G + 0.2% isoflavone conjugates) group, or a FOS and isoflavone diet (AIN-93G + 5% FOS + 0.2% isoflavone conjugates) group. After 6 wk, the mice were killed and the blood and femora were sampled immediately. In OVX mice, both isoflavone conjugates and FOS prevented femoral bone loss. An additive effect of dietary isoflavone conjugates and FOS was observed by dual-energy X-ray absorptiometry in the distal part of the femur and in trabecular bone, by peripheral quantitative computed tomography. Moreover, FOS increased cecal beta-glucosidase activity and equol production from daidzein in both OVX and surgical control mice fed isoflavone conjugates. These results suggest that FOS increase the bioavailability of isoflavones, leading to cooperative effects in the prevention of osteopenia in OVX mice.     

Short- and long-term effects of calcium and exercise on bone mineral density in ovariectomized rats

At the level of prevention of bone mineral loss produced by ovariectomy, the aim of the present study was to determine the effect produced by supplementation of Ca in the diet and a moderate exercise programme (treadmill), simultaneously or separately, in ovariectomized rats, an experimental model of postmenopausal bone loss. Female Wistar rats (n 110, 15 weeks old) were divided into five groups: (1) OVX, rats ovariectomized at 15 weeks of age, fed a standard diet; (2) SHAM, rats sham operated at 15 weeks of age, fed a standard diet; (3) OVX-EX, ovariectomized rats, fed a standard diet and performing the established exercise programme; (4) OVX-Ca, ovariectomized rats fed a diet supplemented with Ca; (5) OVX-EXCa, ovariectomized rats with the exercise programme and diet supplemented with Ca. The different treatments were initiated 1 week after ovariectomy and were continued for 13 weeks for subgroup 1 and 28 weeks for subgroup 2, to look at the interaction of age and time passed from ovariectomy on the treatments. Bone mineral density (BMD) was determined, at the end of the study, in the lumbar spine (L2, L3 and L4) and in the left femur using a densitometer. Bone turnover was also estimated at the end of the study, measuring the serum formation marker total alkaline phosphatase (AP) and the resorption marker serum tartrate-resistant acid phosphatase (TRAP). As expected, OVX rats showed a significant decrease (P<0.05) in BMD, more pronounced in subgroup 2, and a significant increase in AP and TRAP with regard to their respective SHAM group. The simultaneous treatment with Ca and exercise produced the best effects on lumbar and femoral BMD of ovariectomized rats, partially avoiding bone loss produced by ovariectomy, although it was not able to fully maintain BMD levels of intact animals. This combined treatment produced a significant increase in AP, both in subgroups 1 and 2, and a decrease in TRAP in subgroup 1, with regard to OVX group. The exercise treatment alone was able to produce an increase in BMD with regard to OVX group only in subgroup 1 of rats (younger animals and less time from ovariectomy), but not in subgroup 2. In agreement with this, there was an increase of AP in both subgroups, lower than that observed in animals submitted to exercise plus Ca supplement, and a decrease of TRAP in subgroup 1, without significant changes in this marker in the older rats. Ca treatment did not produce any significant effect on BMD in OVX rats in both subgroups of animals, showing a decrease of AP and TRAP levels in the younger animals with no significant variations in markers of bone remodelling in the older female rats compared with their respective OVX group.     

Prolonged feeding of difructose anhydride III increases strength and mineral concentrations of the femur in ovariectomized rats

This study demonstrates that feeding difructose anhydride III (DFAIII) improves bone strength and femoral mineral concentrations in a rat model of oestrogen deficiency. We showed the relationship between Ca, Mg and P absorption and bone characteristics in rats. Two groups of female Sprague-Dawley rats (6 weeks old) underwent bilateral ovariectomy (ovariectomized rats, OVX rats) or bilateral laparotomy (sham rats). At 10 weeks old, OVX and sham rats were divided into three subgroups and fed a control, 1.5 % DFAIII or 3 % DFAIII diet for 8 weeks, respectively. Ca but not Mg absorption rates were lowered by ovariectomy; however, ingestion of the 1.5 % and 3 % DFAIII diets similarly restored the reduced Ca absorption in OVX rats at 4 and 8 weeks after feeding of the test diets. DFAIII increased Mg absorption dose-dependently in sham and OVX rats. The bone strength, femoral Ca and Mg concentrations, and distal bone mineral density in the 3 % DFAIII group were higher than those in the control group in OVX rats. The absorption rates of Ca and Mg were significantly correlated with femoral Ca and Mg concentrations and strength, which suggests that increasing both Ca and Mg absorption improves bone characteristics in OVX rats. There were no differences in any of the variables in the femur between the 1.5 % and 3 % DFAIII groups in OVX rats. In conclusion, feeding of a low dose of DFAIII increased intestinal Ca and Mg absorption, and the promotive effect of DFAIII persisted for over 8 weeks. This effect was associated with prevention of ovariectomy-induced osteopenia.     

Effect of chlorella and its fractions on blood pressure, cerebral stroke lesions, and life-span in stroke-prone spontaneously hypertensive rats

Effects of Chlorella regularis (dried cell powder)--cultured axenically under heterotrophic conditions, and provided as a dietary supplement--and its fractions on the blood pressure, cerebral stroke lesions, and life-span of stroke-prone spontaneously hypertensive rats (SHRSP/Izm) were investigated. When SHRSP were fed on diets with supplemented Chlorella to a commercial diet (Funabashi SP), elevation of blood pressure was significantly lower in the Chlorella groups than in the control group. At 21 wk of feeding, serum total cholesterol was significantly lower in the Chlorella groups than in the control group. Histopathological examination revealed cerebral vascular accidents in the brains of the control group, but those of Chlorella groups showed apparently low incidence compared to the control group. The average life-span of the Chlorella groups were significantly longer than that of the control group (p < 0.001). Chlorella powder was fractionated into three fractions, lipid-soluble, hot water-soluble, and residual fractions. The diets supplemented with lipid or residual fractions equivalent to 10% Chlorella significantly suppressed elevation of blood pressure in SHRSP, and then decreased the incidence rate of cerebral vessel lesions compared to the control group. Chemical analysis revealed that the lipid fraction contained large quantities of antioxidants, including carotenoids (especially lutein) and others, and phospholipids involved in aorta collagen and elastin metabolism; the residual fraction contained high concentrations of arginine, enhancing the function of blood vessels. The control diet contained only a little these substances. These experimental results suggest that the beneficial effect of Chlorella on SHRSP is caused by the synergistic action of several ingredients of Chlorella, which play a role in sustention of a vascular function of rats.     

Milk whey protein enhances the bone breaking force in ovariectomized rats

We studied the effects of whey protein (WP) and fractionated WP (HWP; heat-stable WP, LWP; low M.W. WP, EWP; ethanol-precipitated WP) on calcium and bone metabolism in ovariectomized (OVX) rats. Six-week-old female Sprague-Dawley rats were ovariectomized and fed a low-calcium diet (0.03% Ca, 0.3% P) for 4 weeks. The rats were divided into five groups, Cont, WP, HWP, LWP and EWP group, and were fed a Cont diet (20% casein, 0.3% Ca) or a diet (19% casein, 0.3% Ca) containing 1% WP, HWP, LWP or EWP for 4 weeks. There were no significant differences in the calcium balance, serum calcium and calcitonin levels among the experimental groups. However, serum ALP activity of the HWP and EWP groups at 14 wks. were lower than that of the Cont group. The bone breaking strength and energy of femur of the HWP, LWP and EWP groups were higher than those of the Cont group. As for the amount of calcium, phosphorus, and magnesium in the femur, there were no significant differences among the experimental groups; however, the amounts of total amino acids in the femur of the HWP, LWP and EWP groups were higher than that of the Cont group. The amounts of proline and hydroxyproline (typical amino acids of collagen) in the femur of the HWP, LWP and EWP groups were also higher than those of the Cont group. These data indicate that milk WP contains active components that influence bone metabolism in OVX rats by increasing in bone protein such as collagen and enhance the bone breaking force (strength and energy). These results suggest that the active components are existed in heatstable, low M.W. and 30–70% ethanol-precipitated fraction, respectively.     

海尔福对去卵巢和铅中毒大鼠骨组织及血液影响的实验研究

目的:观察海尔福对去卵巢和铅中毒大鼠骨组织及血液影响,了解海尔福对去卵巢和铅中毒大鼠骨骨质疏松治疗作用,为雌激素缺乏和铅中毒所引致骨质疏松症的防治提供实验依据。方法:选取5月龄健康雌性大鼠100只,分成5组。对照组、去卵巢模型组(OVX)、铅中毒模型组(LPD)、海尔福+去卵巢模型组(H+OVX)和海尔福+铅中毒模型组(H+LPD)。16周后,麻醉大鼠取左心血,处死后取双侧股骨。股骨切片光镜观察骨组织形态结构,并对血液中的钙、磷、铅、碱性磷酸酶和雌二醇进行测定,数据进行统计学分析。结果:H+LPD组骨组织结构、血钙、血磷和血红蛋白及碱性磷酸酶和雌二醇正常;0VX组、LPD组和H+OVX组的血钙及血磷均明显降低(P﹤0.01),血碱性磷酸酶活力升高(P﹤0.01),骨组织形态呈现骨质疏松的病理改变;0VX组和H+OVX组的雌二醇降低(P﹤0.01);LPD组的血铅明显高于对照组(P﹤0.01)。结论:去卵巢和铅中毒均可引起大鼠骨质疏松,铅中毒影响血红蛋白合成,海尔福对铅中毒所致的大鼠骨质疏松有治疗作用,而对雌激素缺乏大鼠骨质疏松治疗无效。     

A diet supplemented with husks of Plantago ovata reduces the development of endothelial dysfunction, hypertension, and obesity by affecting adiponectin and TNF-alpha in obese Zucker rats

The aim of the present study was to analyze whether consumption of a fiber-supplemented diet containing 3.5% Plantago ovata husks prevented many of the abnormalities clustered in the metabolic syndrome, including obesity, dyslipidemia, hypertension and endothelial dysfunction. For this purpose, obese Zucker rats, a model of type 2 diabetes, and their lean littermates were studied. Rats consumed a standard control diet or that diet supplemented with 3.5% P. ovata husks for 25 wk. Body weights were measured weekly. Systolic blood pressure (SBP) was measured monthly. At the end of the treatment, plasma concentrations of triglycerides, total cholesterol, FFAs, glucose, insulin, adiponectin, and tumor necrosis factor alpha (TNF-alpha) were determined, and studies on vascular function were performed using aortic rings. Rats fed the P. ovata husk-supplemented diet had a significantly reduced body weight gain compared with those fed the standard diet. Decreased endothelium-dependent relaxation in response to acetylcholine (ACh) by aortic rings from obese Zucker rats was improved in those fed the fiber-supplemented diet. The greater SBP, higher plasma concentrations of triglycerides, total cholesterol, FFA, glucose, insulin, and TNF-alpha, and the hypoadinectinemia that occurred in obese Zucker rats that consumed the control diet were significantly improved in those fed the fiber-supplemented diet. We conclude that intake of a P. ovata husk-supplemented diet prevents endothelial dysfunction, hypertension, and obesity development, and ameliorates dyslipidemia and abnormal plasma concentrations of adiponectin and TNF-alpha in obese Zucker rats.     

白藜芦醇对去卵巢大鼠骨密度的影响

目的:探讨白藜芦醇(RES)对去卵巢大鼠骨密度(BMD)的影响。方法:48只SD大鼠随机分为6组,分别接受假手术(A)、去卵巢(B)、去卵巢+0.03mg/(kgbw·d)己烯雌酚(DES,C)、去卵巢+RES5、15和45mg/(kgbw·d)(D,E,F)90d后,用双能X线吸收法测定大鼠的骨密度,观察其改变。结果:B组大鼠各BMD测定指标均显著低于A组,D、E、F组全身和腰椎BMD均显著高于B组,E、F组整体股骨BMD显著高于B组。结论:白藜芦醇对去卵巢大鼠的骨丢失有抑制作用,以45mg/(kgbw·d)剂量对骨密度的保护效果最好。     

Effects of tuna bone and herbal extract on bone metabolism in ovariectomized rats

This study was conducted to examine the effects of herb extract addition on bone metabolism of ovariectomized (OVX) rats fed a diet with tuna bone as a source of calcium. The experimental groups were sham–control (CaCO₃ [CC]), OVX-CC (OVX-control), OVX–CC + herb extract, OVX–tuna bone powder (TB), OVX–tuna bone powder + herb extract, OVX–citrated tuna bone powder (CTB), and OVX–citrated tuna bone powder + herb extract (CTBH). The herb extract included Rehmanniae radix and Angelicae gigantis radix, following the prescribed theories of Oriental herb medicine. In the OVX-CTBH group, the level of fecal (33.6%) and urinary calcium excretion (45.8%) greatly decreased compared with the TB groups. Osteocalcin concentrations were significantly lower in the OVX-CC group and higher in the OVX-CTB group. The deoxypyridinoline value was significantly influenced by ovariectomy. It was elevated in all OVX groups compared with the sham group, and it was reduced by 12.8% in rats supplemented with the herb extract. The bone density value per 100-g body weight was lowest in the TB group, and it was higher in the tuna bone powder + herb extract, CTB, and CTBH groups. We concluded that TB can be a good calcium source, and it was effective in maintaining skeletal metabolism of OVX rats when it was fed in the form of citrated or herb extract–supplemented diets.     

Genistein may prevent cadmium-induced bone loss in ovariectomized rats

This study compared the ability of genistein, a soy isoflavone, with that of 17 beta-estradiol to prevent bone loss in cadmium (Cd)-exposed ovariectomized (OVX) rats during growth. Female Wistar rats (4 weeks old) were either sham-operated (SH; n = 9/group) or OVX and placed on experimental diets (n = 9/group): OVX; OVX rats fed 50 ppm of CdCl(2) (OVX-Cd); OVX fed 50 ppm of CdCl(2) and 10 microg/kg of body weight genistein (OVX-Cd-G); and OVX fed 50 ppm of CdCl(2) and 10 microg/kg of body weight estrogen (OVX-Cd-E). All rats were given free access to AIN-76 modified diet and drinking water, with or without Cd, for 8 weeks. The OVX groups gained more body weight than the SH group. Femoral weight was increased by feeding genistein and estradiol, whereas femoral length among groups was not significantly different. Femoral Cd content was significantly higher in the OVX-Cd group than in the other groups. Both serum osteocalcin and calcium (Ca) concentrations, as well as urinary Ca, were significantly higher in the OVX-Cd group than in the other groups. Urinary excretion of Cd was significantly increased in Cd-OVX-G rats, and fecal Cd excretion was increased by feeding both genistein and estradiol. Femoral histomorpological changes in proliferative cartilage and hypertrophic cells in the OVX-Cd group showed that both cell types were decreased by feeding Cd, and irregular arrangements were observed in proliferative cells. However, both cells types exhibited normal distribution in OVX-Cd-G and OVX-Cd-E groups. These findings suggest that Cd/OVXinduced osteopenia or osteoporosis probably results from an increase in bone turnover. Genistein may be involved in stimulating Cd excretion and inhibiting Ca excretion from bone.