Effects of ovariectomy and ascorbic acid supplement on oxidative stress parameters and bone mineral density in rats

Isoflavone and Antioxidant of Instant Cream Soup Made from Pumpkin and Tempeh and Their Active Compound in Ovariohysterectomy Rat-Induced Alzheimer’s Disease

Menopause period associated with brain function disorders can caused by decreasing estradiol levels and increasing oxidative stress in the body. Antioxidant agents are required to balance oxidative stress in the body. Instant cream soup made from pumpkin and tempeh is a supplementary food containing isoflavone and antioxidant agents. This study is aimed at analyzing the content of antioxidant level and isoflavones (genistein and daidzein) in instant cream soup and their effect on ovariohysterectomy (OVx) rats. Instant pumpkin cream soup with and without tempeh were subjected to isoflavone content and antioxidant analysis. Serum estradiol was analyzed using enzyme-linked immunosorbent assay. Liver concentration of malondialdehyde (MDA) and activities of superoxide dismutase (SOD) were measured by spectrophotometric methods. The study showed that the isoflavone content (genistein 370.86 g/100 g, daidzein 185.61 g/100 g) was only present in the pumpkin instant cream soup with tempeh (IPTS). IPTS has higher antioxidant levels (134.25 mg AEAC/100 g) than instant pumpkin cream soup without tempeh (IPS). In vivo study, experimental rats showed that OVx increased malondialdehyde (MDA) levels up to 5.85-6.07 nmol mL-1 as compared to control (4.47 nmol mL-1). Moreover, instant pumpkin cream soup with tempeh treatments significantly increased serum estradiol levels (2.37–3.63 μg) and superoxide dismutase (SOD) levels of 497.49-558.89 U mL-1. This study concluded that instant pumpkin cream soup and tempeh contained isoflavone and antioxidant, and it increased estradiol serum and SOD level.

Long-term inorganic nitrate administration protects against ovariectomy-induced osteoporosis in rats

The risk of osteoporotic fractures increases in women after menopause. This study aims at determining the effects of long-term inorganic nitrate administration against ovariectomy-induced osteoporosis in rats. Rats were divided into 4 groups (n=6/group): Control, control+nitrate, ovariectomized (OVX), and OVX+nitrate. Sodium nitrate (100 mg/L in drinking water) was administered for 9 months. Trabecular bone quality in the proximal tibia was measured using a Micro-Computed Tomography (micro-CT) scanner at months 0, 1, 3, and 9. Levels of nitric oxide (NO) metabolites (NOx) and oxidative stress indices, and mRNA expression of endothelial NO synthase (eNOS) were measured at month 9 in the proximal tibia. Compared to controls, OVX rats had lower NOx levels by 47 %, eNOS mRNA expression by 55 %, catalase activity (CAT) by 45 %, total antioxidant capacity (TAC) by 70 %, and higher malondialdehyde (MDA) levels by 327 % in the bone tissue at month 9. OVX rats, compared to controls, had lower bone volume/tissue volume (BV/TV), trabecular number (Tb.N.), and trabecular thickness (Tb.Th.) by 32 %, 58 %, and 17 %, respectively, and higher trabecular separation (Tb.Sp.) by 123 %, at month 9. Nitrate administration to control rats increased TAC by 46 % in the bone tissue at month 9 but did not significantly affect other parameters in serum and bone tissue. Nitrate in OVX rats significantly increased NOx levels by 86 %, eNOS expression by 2.14-fold, CAT activity by 75 %, TAC by 170 %, and decreased MDA levels by 36 % at month 9 in the bone tissue. Nitrate-treated OVX rats at month 9 had higher BV/TV (42 %) and Tb.N. (61 %) and lower Tb.Sp. (15 %). Long-term inorganic nitrate administration at a low dose has protective effects against OVX-induced osteoporosis in rats; this effect is associated with increasing eNOS-derived NO and decreasing oxidative stress in the bone tissue.

The Role of Macronutrients, Micronutrients and Flavonoid Polyphenols in the Prevention and Treatment of Osteoporosis

Osteoporosis is considered an age-related disorder of the skeletal system, characterized primarily by decreased bone mineral density (BMD), microstructural quality and an elevated risk of fragility fractures. This silent disease is increasingly becoming a global epidemic due to an aging population and longer life expectancy. It is known that nutrition and physical activity play an important role in skeletal health, both in achieving the highest BMD and in maintaining bone health. In this review, the role of macronutrients (proteins, lipids, carbohydrates), micronutrients (minerals—calcium, phosphorus, magnesium, as well as vitamins—D, C, K) and flavonoid polyphenols (quercetin, rutin, luteolin, kaempferol, naringin) which appear to be essential for the prevention and treatment of osteoporosis, are characterized. Moreover, the importance of various naturally available nutrients, whether in the diet or in food supplements, is emphasized. In addition to pharmacotherapy, the basis of osteoporosis prevention is a healthy diet rich mainly in fruits, vegetables, seafood and fish oil supplements, specific dairy products, containing a sufficient amount of all aforementioned nutritional substances along with regular physical activity. The effect of diet alone in this context may depend on an individual’s genotype, gene-diet interactions or the composition and function of the gut microbiota.

Sufficient Plasma Vitamin C Is Related to Greater Bone Mineral Density among Postmenopausal Women from the Boston Puerto Rican Health Study

BACKGROUND

Vitamin C may benefit bone as an antioxidant.

OBJECTIVES

This cross-sectional study evaluated associations between dietary, supplemental, and plasma vitamin C with bone mineral density (BMD) among Puerto Rican adults.

METHODS

Diet was assessed by food-frequency questionnaire (n = 902); plasma vitamin C, measured in fasting blood (n = 809), was categorized as sufficient (≥50 μmol/L), insufficient (20-49 μmol/L), or low (<20 μmol/L). Associations between vitamin C and BMD (measured by DXA) were tested, with false discovery rate correction for multiple comparisons, and interactions by smoking, sex, and estrogen status. Least-squares mean BMDs were compared across tertiles of diet and plasma vitamin C.

RESULTS

Participants' mean age was 59 ± 7 y (range: 46-78 y), 72% were women, mean dietary vitamin C was 95 ± 62 mg/d, and plasma vitamin C ranged from 1.7 to 125 μmol/L. No associations were observed between dietary vitamin C and BMD (P-value range: 0.48-0.96). BMD did not differ by vitamin C supplement use (P-value range: 0.07-0.29). Total femur BMD was higher (P = 0.04) among plasma vitamin C-sufficient participants (mean: 1.06; 95% CI: 1.035, 1.076 g/cm2) compared with low plasma vitamin C participants (1.026; 0.999, 1.052 g/cm2) in adjusted models. Findings at the trochanter were similar (P = 0.04). Postmenopausal women without estrogen therapy, with sufficient plasma vitamin C, showed greater total femur BMD (1.004 ± 0.014 g/cm2) compared to those with low plasma vitamin C (0.955 ± 0.017 g/cm2; P = 0.001). Similar findings were observed at the trochanter (P < 0.001). No significant associations were observed among premenopausal women or those with estrogen therapy or men. Interactions with smoking status were not significant.

CONCLUSIONS

Dietary vitamin C was not associated with BMD. Low plasma vitamin C, compared with sufficiency, was associated with lower hip BMD, particularly among postmenopausal women without estrogen therapy. Future research is needed to determine whether vitamin C status is associated with change in BMD or reduction in fracture risk.

Osteoprotective effects of kefir fortified with omega-3 and vitamin C in ovariectomized rats

Nutritional interventions can be valuable for the prevention of postmenopausal osteoporosis. This study aimed to investigate the effects of kefir fortified with omega-3 and vitamin C on the bone and uterus parameters of ovariectomized rats. Seventy-seven female Sprague-Dawley rats were ovariectomized or sham-operated. The ovariectomized rats were assigned to six groups and received 1 ml/day of distilled water (OVX group), milk, kefir, kefir fortified with omega-3 (kefir+ω3), kefir fortified with vitamin C (kefir+vit-C) or kefir fortified with omega-3 and vitamin C (kefir+ω3+vit-C) for 12 weeks. The sham group also received 1ml/day of distilled water. Subsequently, bone mineral content (BMC) and bone mineral density (BMD) of various bones were assessed. Femurs and uteri were harvested for bone ash analysis and histopathological examinations, respectively. Sera were analyzed for carboxy-terminal cross-linked telopeptide of type 1 collagen, procollagen type 1 amino-terminal propeptide, calcium, phosphorous, tumor necrosis factor-α (TNF-α) and total antioxidant capacity levels. Ovariectomy resulted in significant reduction in bone density (P<0.05). Kefir+ω3+vit-C significantly improved BMC of lumbar spine (0.699±0.027 g compared with 0.580±0.018 in the OVX group), and kefir, kefir+vit-C and kefir+ω3+vit-C significantly increased BMD of tibia (0.118±0.003 g/cm², 0.119±0.001 and 0.120±0.004 compared with 0.102±0.005 in the OVX group). Moreover, ovariectomy markedly elevated TNF-α level, which was significantly reversed by kefir+ω3+vit-C. Significant atrophy of the uterus was observed following ovariectomy, although the uterus parameters did not change by any of the interventions. In conclusion, kefir fortified with omega-3 and vitamin C may have protective effects against bone loss through suppressing inflammation.

Functional Food for Elderly High in Antioxidant and Chicken Eggshell Calcium to Reduce the Risk of Osteoporosis-A Narrative Review

The elderly population is increasing globally and is predicted to reach 1.5 billion in 2050. The quality of life of the elderly must be concerned, for example, with developing functional food for the elderly. In this article, the development of functional food to reduce the risk of osteoporosis in the elderly is reviewed. Oxidative stress is one of the factors which accelerates osteoporosis. Various antioxidants, including vitamin C, vitamin E, polyphenols, or lycopene, have been proven by former studies to have antioxidant activity, therefore, could reduce the risk of osteoporosis. Additionally, the application of eggshell powder in various food products has been reported to improve calcium intake, and its usage is environmentally sustainable as this could contribute to reducing food waste. The application of both antioxidants and calcium could be a good combination, but the amount of some antioxidants must be concerned so it would not interfere with the bioavailability of calcium. Therefore, this review aims to explore the functional food for the elderly to reduce the risk of osteoporosis, particularly with antioxidants and calcium from chicken eggshells. The eating preference and dietary pattern of the elderly are also considered to determine the suitable form of functional food for the elderly. The results presented in the study may be the basis for the development of new calcium-enriched food products for the elderly.

Salvianolic acid B stimulates osteogenesis in dexamethasone-treated zebrafish larvae

AIM

Our previous studies show that salvianolic acid B (Sal B) promotes osteoblast differentiation and matrix mineralization. In this study, we evaluated the protective effects of Sal B on the osteogenesis in dexamethasone (Dex)-treated larval zebrafish, and elucidated the underlying mechanisms.

METHODS

At 3 d post fertilization, wild-type AB zebrafish larvae or bone transgenic tg (sp7:egfp) zebrafish larvae were exposed to Sal B, Dex, or a mixture of Dex+Sal B for 6 d. Bone mineralization in AB strain larval zebrafish was assessed with alizarin red staining, and osteoblast differentiation in tg (sp7:egfp) larval zebrafish was examined with fluorescence scanning. The expression of osteoblast-specific genes in the larvae was detected using qRT-PCR assay. The levels of oxidative stress markers (ROS and MDA) in the larvae were also measured.

RESULTS

Exposure to Dex (5-20 μmol/L) dose-dependently decreased the bone mineralization area and integral optical density (IOD) in wild-type AB zebrafish larvae and the osteoblast fluorescence area and IOD in tg (sp7:egfp) zebrafish larvae. Exposure to Dex (10 μmol/L) significantly reduced the expression of osteoblast-specific genes, including runx2a, osteocalcin (OC), alkaline phosphatase (ALP) and osterix (sp7), and increased the accumulation of ROS and MDA in the larvae. Co-exposure to Sal B (0.2-2 μmol/L) dose-dependently increased the bone mineralization area and IOD in AB zebafish larvae and osteoblast fluorescence in tg (sp7:egfp) zebrafish larvae. Co-exposure to Sal B (2 μmol/L) significantly attenuated deleterious alterations in bony tissue and oxidative stress in both Dex-treated AB zebafish larvae and tg (sp7:egfp) zebrafish larvae.

CONCLUSION

Sal B stimulates bone formation and rescues GC-caused inhibition on osteogenesis in larval zebrafish by counteracting oxidative stress and increasing the expression of osteoblast-specific genes. Thus, Sal B may have protective effects on bone loss trigged by GC.

The Appraisement of Antioxidant and Oxidant Status in Women Undergoing Surgical Menopause

The present study was undertaken to study the impact of surgical menopause on oxidant and antioxidant status in relation to estrogen levels after 3 months of surgery. Total 130 women who had undergone total hysterectomy (TH) with or without bilateral salpingo-oophorectomy (BSO) were included in this study. The oxidant status was assessed by measuring plasma levels of malondialdehyde and antioxidant status was assessed by measuring superoxide dismutase, catalase, glutathione, glutathione peroxidase, estrogen, and Vitamin A, E and C levels. The malondialdehyde level was significantly increased (p < 0.05) in all women who underwent TH with or without BSO. Significant increased levels of superoxide dismutase were observed in women who underwent TH with BSO. The blood glutathione levels were significantly decreased in women after TH only but significantly increased in women who had undergone TH with BSO. The levels of estrogen, vitamin E and vitamin C were significantly decreased in women who underwent TH with BSO. The catalase, GPx and vitamin A did not differ significantly in all groups. The result suggests that surgical menopause is associated with oxidative stress which reiterates the fact that ovaries retain some function even after menopause.

Osteoporosis, vitamin C intake, and physical activity in Korean adults aged 50 years and over

[Purpose] To investigate associations between vitamin C intake, physical activity, and osteoporosis among Korean adults aged 50 and over. [Subjects and Methods] This study was based on bone mineral density measurement data from the 2008 to 2011 Korean National Health and Nutritional Examination Survey. The study sample comprised 3,047 subjects. The normal group was defined as T-score ≥ -1.0, and the osteoporosis group as T-score ≤ -2.5. The odds ratios for osteoporosis were assessed by logistic regression of each vitamin C intake quartile. [Results] Compared to the lowest quartile of vitamin C intake, the other quartiles showed a lower likelihood of osteoporosis after adjusting for age and gender. In the multi-variate model, the odds ratio for the likelihood of developing osteoporosis in the non-physical activity group significantly decreased to 0.66, 0.57, and 0.46 (p for trend = 0.0046). However, there was no significant decrease (0.98, 1.00, and 0.97) in the physical activity group. [Conclusion] Higher vitamin C intake levels were associated with a lower risk of osteoporosis in Korean adults aged over 50 with low levels of physical activity. However, no association was seen between vitamin C intake and osteoporosis risk in those with high physical activity levels.

Tanshinol Rescues the Impaired Bone Formation Elicited by Glucocorticoid Involved in KLF15 Pathway

Decreased bone formation is responsible for the pathogenesis of glucocorticoid- (GC-) induced osteoporosis (GIO), while the mechanism remains to be elucidated. The aim was to investigate how natural antioxidant tanshinol attenuates oxidative stress and rescues impaired bone formation elicited by GC in Sprague-Dawley rats and in C2C12 cells and/or MC3T3-E1 cells. The results showed that tanshinol prevented bone loss and decreased biomechanical characteristics and suppressed reduction of biomarkers related to osteogenesis in GIO rats. Further study revealed that tanshinol reversed decrease of transcription activity of Osterix-luc and rescued impairment of osteoblastic differentiation and bone formation involved in induction of KLF15 mRNA. Meanwhile, tanshinol diminished inhibition of protein expression of β-catenin and Tcf4 and transcription activity of Tcf4-luc induced by GC, especially under conditions of KLF siRNA in vitro. Additionally, tanshinol attenuated increase of reactive oxygen species (ROS) generation, phosphorylation of p66^Shc expression, TUNEL-positive cells, and caspase-3 activity elicited by KLF15 under conditions of GC. Taken together, the present findings suggest that tanshinol attenuated the decrease of bone formation and bone mass and bone quality elicited by GC involved in KLF15/Wnt signaling transduction and counteracted GC-evoked oxidative stress and subsequent cell apoptosis involved in KLF15/p66^Shc pathway cascade.

Ophiopogonin D: A new herbal agent against osteoporosis

Excessive reactive oxygen species (ROS) play an important role in the development of osteoporosis. Ophiopogonin D (OP-D), isolated from the traditional Chinese herbal agent Radix Ophiopogon japonicus, is a potent anti-oxidative agent. We hypothesized that OP-D demonstrates anti-osteoporosis effects via decreasing ROS generation in mouse pre-osteoblast cell line MC3T3-E1 subclone 4 cells and a macrophage cell line RAW264.7 cells. We investigated OP-D on osteogenic and osteoclastic differentiation under oxidative status. Hydrogen peroxide (H2O2) was used to establish an oxidative damage model. In vivo, we established a murine ovariectomized (OVX) osteoporosis model. Then, we searched the molecular mechanism of OP-D against osteoporosis. Our results revealed that OP-D significantly promoted the proliferation of MC3T3-E1 cells and improved some osteogenic markers. Moreover, OP-D reduced TRAP activity and the mRNA expressions of osteoclastic genes in RAW264.7 cells. OP-D suppressed ROS generation in both MC3T3-E1 and RAW264.7 cells. OP-D treatment reduced the activity of serum bone degradation markers, including CTX-1 and TRAP. Further research showed that OP-D displayed anti-osteoporosis effects via reducing ROS through the FoxO3a-β-catenin signaling pathway. In summary, our results indicated that the protective effects of OP-D against osteoporosis are linked to a reduction in oxidative stress via the FoxO3a-β-catenin signaling pathway, suggesting that OP-D may be a beneficial herbal agent in bone-related disorders, such as osteoporosis.

Relationship between oxidative stress and bone mass in obesity and effects of berry supplementation on bone remodeling in obese male mice: an exploratory study

Berry consumption can prevent bone loss. However, the effects of different berries with distinct anthocyanin composition have not been thoroughly examined. The present study compared the effects of blueberry, blackberry, and black currant on bone health using a mouse model of diet-induced obesity. To investigate the effect of different berry supplements against a high-fat (HF) diet in vivo, 40 HF diet-induced obese (DIO) C57BL mice were assigned into four groups and fed a HF diet (35% w/w) with or without berry supplementation for 12 weeks (n=10). We measured adipose tissue mass (epididymal and retroperitoneal), plasma antioxidant, bone-related biomarkers, femur bone mineral density (BMD), and bone mineral content (proximal and distal). Adipose masses were negatively correlated with proximal BMD, but positively associated with plasma superoxide dismutase (SOD) concentrations (P<.001). Berry supplementation did not change the plasma ferric reducing antioxidant power, SOD, and insulin-like growth factor-1. However, the black currant group exhibited greater plasma alkaline phosphatase compared with the control group (P<.05). BMD in the distal epiphysis was significantly different between the blueberry and blackberry group (P<.05). However, berry supplementation did not affect bone mass compared with control. The present study demonstrates a negative relationship between fat mass and bone mass. In addition, our findings suggest that the anthocyanin composition of berries will affect bone turnover, warranting further research to investigate the underlying mechanisms.

Tanshinol attenuates the deleterious effects of oxidative stress on osteoblastic differentiation via Wnt/FoxO3a signaling

There is now increasing evidence which suggests a pivotal role for oxidative stress in the development and progression of osteoporosis. We confirm herein the protective effects of natural antioxidant Tanshinol against oxidative stress in osteoblastic differentiation and the underlying mechanism. Our results show that hydrogen peroxide (H₂O₂) leads to accumulation of reactive oxygen species (ROS), decrease in cell viability, cell cycle arrest and apoptosis in a caspase-3-dependent manner, and inhibition of osteoblastic differentiation. Tanshinol reverses these deleterious consequence triggered by oxidative stress. Moreover, under the condition of oxidative stress, Tanshinol suppresses the activation of FoxO3a transcription factor and expressions of its target genes Gadd45a and catalase (CAT) and simultaneously counteracts the inhibition of Wnt signalling and expressions of target genes Axin2, alkaline phosphatase (ALP), and Osteoprotegerin (OPG). The findings are further consolidated using FoxO3a siRNA interference and overexpression of Tcf4. The results illustrate that Tanshinol attenuates oxidative stress via down-regulation of FoxO3a signaling, and rescues the decrease of osteoblastic differentiation through upregulation of Wnt signal under oxidative stress. The present findings suggest that the beneficial effects of Tanshinol may be adopted as a novel therapeutic approach in recently recognized conditions of niche targeting osteoporosis.

Hydrogen water consumption prevents osteopenia in ovariectomized rats

BACKGROUND AND PURPOSE

Accumulating evidence indicates an important role of oxidative stress in the progression of osteoporosis. Recently, it was demonstrated that hydrogen gas, as a novel antioxidant, could selectively reduce hydroxyl radicals and peroxynitrite anion to exert potent therapeutic antioxidant activity. The aim of the present work was to investigate the effect of hydrogen water (HW) consumption on ovariectomy-induced osteoporosis.

EXPERIMENTAL APPROACH

Ovariectomized rats were fed with HW (1.3 ± 0.2 mg·L⁻¹) for 3 months. Then, blood was collected and femur and vertebrae were removed for evaluation of the effect of HW on bone.

KEY RESULTS

HW consumption in ovariectomized rats had no significant effect on oestrogen production, but prevented the reduction of bone mass including bone mineral content and bone mineral density in femur and vertebrae, and preserved mechanical strength including ultimate load, stiffness, and energy, and bone structure including trabecular bone volume fraction, trabecular number, and trabecular thickness in femur, and preserved mechanical strength including ultimate load and stiffness, and bone structure including trabecular bone volume fraction and trabecular number in vertebrae. In addition, treatment with HW abated oxidative stress and suppressed IL-6 and TNF-α mRNA expressions in femur of ovariectomized rats; treatment with HW increased femur endothelial NOS activity and enhanced circulating NO level in ovariectomized rats.

CONCLUSIONS AND IMPLICATIONS

HW consumption prevents osteopenia in ovariectomized rats possibly through the ablation of oxidative stress induced by oestrogen withdrawal.

Update on nutrients involved in maintaining healthy bone

Osteoporosis is a leading cause of morbidity and mortality in the elderly and influences quality of life, as well as life expectancy. Currently, there is a growing interest among the medical scientists in search of specific nutrients and/or bioactive compounds of natural origin for the prevention of disease and maintenance of bone health. Although calcium and vitamin D have been the primary focus of nutritional prevention of osteoporosis, a recent research has clarified the importance of several additional nutrients and food constituents. Based on this review of the literature, supplementation with vitamins B, C, K, and silicon could be recommended for proper maintenance of bone health, although further clinical studies are needed. The results of studies on long-chain polyunsaturated fatty acids, potassium, magnesium, copper, selenium, and strontium are not conclusive, although studies in vitro and in animal models are interesting and promising.