Consumption of legumes improves certain bone markers in ovariectomized rats

Oxidative Stress and Osteoporosis

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Oxidative stress has been implicated as a causative factor in many disease states, possibly including the diminished bone mineral density in osteoporosis.

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Understanding the effects of oxidative stress on the development of osteoporosis may lead to further research improving preventative and therapeutic measures that can combat this important contributor to morbidity and mortality worldwide.

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A diet rich in whole plant foods with high antioxidant content along with antioxidant-preserving lifestyle changes may improve bone mineral density and reduce the risk of fragility-related fractures. While it is not explicitly clear if antioxidant activity is the effector of this change, the current evidence supports this possibility.

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Supplementation with isolated antioxidants may also provide some osteoprotective benefits, but whole plant food-derived antioxidants potentially have more overall benefits. Larger-scale clinical trials are needed to give credence to definitive clinical recommendations.

Anti-climacterium effects of pomegranate concentrated solutions in ovariectomized ddY mice

In the present study, the complex anti-climacterium potential of standardized pomegranate concentrated solution (PCS) was investigated using bilateral ovariectomy (OVX) female ddY mice. Changes in body weight and gain during experimental periods, food consumption, serum estradiol levels, total body and abdominal fat densities, abdominal fat pads, and uterus weights were observed, along with the histopathology of abdominal fat pads and uterus for anti-obesity and estrogenic effects. In addition, liver weights, serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) levels, and histopathological inspections were performed to explore the hepato-protective effects. Serum total cholesterol (TC), low density lipoprotein (LDL), high density lipoprotein, and triglyceride (TG) levels were monitored for hypolipidemic effects with total body and femur mean bone mineral density (BMD), right femur wet, dry and ash weights, strength, serum osteocalcin, bone-specific alkaline phosphatase (bALP) contents, and histological and histomorphometrical analyses for anti-osteoporosis activity. As a result of OVX, notable increases in body weight and gains, food consumption, abdominal fat mass densities, weights of abdominal fat pads deposited in the abdominal cavity, and serum AST, ALT, TC, LDL, TG, and osteocalcin levels were observed, along with decreases in the uterus, liver, and femur weights, mean total body and femur BMD, femur strength, serum bALP, and estradiol levels. In addition, marked hypertrophic alterations in adipocytes located in the deposited abdominal fat pads, liver steatosis, uterine disused atrophic changes, and decreases in bone mass and structures of the femur were also observed in OVX control mice with significant increases in bone resorption markers based on histopathological and histomorphometrical analysis. However, these estrogen-deficient climacterium symptoms were significantly (P<0.05 or P<0.01) inhibited after 84 days of continuous treatment with estradiol and PCS (1, 2 and 4 ml/kg), respectively. The present results suggested that PCS was able to effectively inhibit or refine the climacterium symptoms, including obesity, hyperlipidemia, hepatic steatosis, and osteoporosis, induced by OVX in ddY mice.

Regulation of the differentiation of osteoblasts and osteoclasts by a hot-water extract of adzuki beans (Vigna angularis)

Osteoporosis is a global public health problem thought to be caused by an imbalance in bone metabolism. We examined in this study the 40% ethanol fraction of HP-20 resin in combination with a hot-water adzuki extract (EtEx.40) for its effect on osteoblast and osteoclast differentiation. EtEx.40-treated murine preosteoblast MC3T3-E1 cells exhibited significantly elevated alkaline phosphatase activity and mineralization. EtEx.40 facilitated osteoblast differentiation by up-regulating such osteoblast differentiation-related molecules as runt-related transcription factor 2, distal-less homeobox 5, and osterix via p38 mitogen-activated protein kinase. EtEx.40 also suppressed the formation of large tartrate-resistant acid phosphatase-positive multinucleated cells in RAW264.7 cells that had been stimulated with the receptor activator of the nuclear factor κB ligand/macrophage colony-stimulating factor. EtEx.40 significantly inhibited NF-κB activation, thus reducing the expression of such downstream molecules as c-Fos and NFATc1. Our findings suggest that EtEx.40 could be used to maintain bone mass.

Effect of dimethyl sulfoxide on inhibition of post-ovariectomy osteopenia in rats

There is increasing evidence that oxidative stress, due to estrogen deficiency, leads to osteopenia. In this study, dimethyl sulfoxide (DMSO), an antioxidant solvent, was used against post-ovariectomy osteopenia (PO) in rats. Forty female rats were divided into 5 groups randomly as follows: Sham, control group; OVX, ovariectomized group; DMSO1, ovariectomized injected DMSO (0.5 ml/kg/d ip); DMSO2, ovariectomized injected DMSO (1 ml/kg/day ip) and DMSO3, ovariectomized injected DMSO (2 ml/kg/d ip). DMSO therapy started 1 week after ovariectomy and continued for 13 weeks. After 13th weeks, sera were prepared, and then L4 vertebrae and right tibial bones rinsed in fixative. Serum bone alkaline phosphatase (BALP), osteocalcin, pyridinoline, malondialdehyde (MDA) and glutathione (GSH) were measured. Trabecular volume density, trabecular and cortex thickness were estimated. Osteoclast and osteoblast numbers were counted morphometrically. The data were analyzed by ANOVA and then post hoc Tukey test at p < 0.05. The increase of pyridinoline and decrease of BALP in DMSO injected groups were inhibited compared with OVX group (p < 0.05). In DMSO injected groups, decrease of bone density, trabecular volume density, thickness of trabecular and tibial cortex were inhibited compared with OVX group (p < 0.05). MDA decreased significantly in DMSO injected groups compared with OVX group. Osteoclast number decreased in DMSO injected groups compared with OVX group (p < 0.05). Osteoblast number did not show significant change in DMSO groups compared with OVX group. In conclusion, DMSO ameliorates PO through decrease of osteoclast number, osteoclast inhibition and osteoblast activation. These effects may probably be mediated via antioxidant property of DMSO.

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.