Dietary restriction of lycopene for a period of one month resulted in significantly increased biomarkers of oxidative stress and bone resorption in postmenopausal women

The role of carotenoids in bone health-A narrative review

Osteoporosis constitutes a serious challenge for public health. Dietary patterns belong to important, modifiable risk factors of this disease. Therefore, what and in what quantities we consume on a daily basis are extremely relevant. It is commonly known that bone health is positively affected by vitamins (e.g., vitamin D and vitamin K) as well as mineral components (e.g., calcium and magnesium). However, the human diet consists of many other groups of compounds that exhibit a potential antiosteoporotic and supporting bone-building effect. These dietary components include carotenoids. This paper presents a broad review of studies on the influence of particular carotenoids (β-carotene, lutein, zeaxanthin, β-cryptoxanthin, and lycopene) on bones. The paper discusses up-to-date in vitro experiments and research on animal models and presents how the results translate into clinical effect in humans.

Association between Phytochemical Index and Osteoporosis in Women: A Prospective Cohort Study in Korea

Osteoporosis is a prevalent issue among postmenopausal women, who have a higher incidence of the condition than men. This study aimed to examine the relationship between phytochemical-rich food intake and osteoporosis incidence in premenopausal and postmenopausal women. The data analyzed included 4600 women aged 40–69 who were free of osteoporosis at baseline, with dietary intake evaluated through a semi-quantitative food frequency questionnaire and osteoporosis prevalence determined using interviewer-administered questionnaires and bone mineral density tests. The phytochemical index (PI) was calculated to reflect the intake levels of phytochemical-rich foods. Postmenopausal women in the highest PI quartile had a 16% lower risk of osteoporosis (95% confidence interval (CI): 0.71 to 0.99, p for trend = 0.02) than those in the lowest quartile, while no significant association was observed among premenopausal women (hazard ratio: 0.98, 95% CI: 0.78 to 1.24, p for trend = 0.8). These findings suggest that consuming phytochemical-rich foods may have a protective effect against osteoporosis in postmenopausal women, offering valuable scientific insights. However, additional research is needed to validate these findings using biochemical data. Overall, this study highlights the potential of dietary interventions to reduce the risk of osteoporosis in postmenopausal women.

Oxidative Stress and Natural Antioxidants in Osteoporosis: Novel Preventive and Therapeutic Approaches

This review reports in detail the cellular and molecular mechanisms which regulate the bone remodeling process in relation to oxidative stress (OS), inflammatory factors, and estrogen deficiency. OS is considered an important pathogenic factor of osteoporosis, inducing osteocyte apoptosis and varying levels of specific factors, such as receptor activator κB ligand (RANKL), sclerostin, and, according to recent evidence, fibroblast growth factor 23, with consequent impairment of bone remodeling and high bone resorption. Bone loss increases the risk of fragility fractures, and the most commonly used treatments are antiresorptive drugs, followed by anabolic drugs or those with a double effect. In addition, recent data show that natural antioxidants contained in the diet are efficient in preventing and reducing the negative effects of OS on bone remodeling and osteocytes through the involvement of sirtuin type 1 enzyme. Indeed, osteocytes and some of their molecular factors are considered potential biological targets on which antioxidants can act to prevent and reduce bone loss, as well as to promote bone anabolic and regenerative processes by restoring physiological bone remodeling. Several data suggest including antioxidants in novel therapeutic approaches to develop better management strategies for the prevention and treatment of osteoporosis and OS-related bone diseases. In particular, anthocyanins, as well as resveratrol, lycopene, oleuropein, some vitamins, and thiol antioxidants, could have protective and therapeutic anti-osteoporotic effects.

The Nutraceutical Genistein-Lycopene Combination Improves Bone Damage Induced by Glucocorticoids by Stimulating the Osteoblast Formation Process

Chronic glucocorticoid (GC) therapy is the most common cause of iatrogenic osteoporosis and represents an important risk factor for osteoporosis and bone fractures. New therapeutic approaches are required in order to treat osteoporosis and reduce the side effects related to the use of anti-osteoporotic drugs. In this context, previous studies reported the efficacy of some isoflavones and carotenoids, such as lycopene and genistein, on the reduction of the risk of fracture related to osteoporosis. The aim of this study was to investigate the effects of a combined oral treatment, consisting of genistein and lycopene, in an experimental model of glucocorticoid-induced osteoporosis (GIO). GIO was induced by subcutaneous injection of methylprednisolone (MP, 30 mg/kg) for 60 days, whereas the control group (Sham) received saline solution only. Following induction, MP animals randomly were assigned to receive alendronate, genistein, lycopene, or the association of genistein and lycopene or saline solution for additional 60 days together with MP. Femurs obtained from the Sham group were used for osteoblasts extraction; they were then incubated with dexamethasone (DEX) for 24 h to be then treated with lycopene or genistein or the association of lycopene and genistein for an additional 24 h. Treatments with lycopene and genistein restored the impaired mineralization of cells observed following DEX treatment and stimulated osteoblast differentiation by increasing the depressed expression of bALP and RUNX2 (p < 0.0001). Wnt5a, β-catenin, and Nrf-2 expression were significantly increased following genistein and lycopene treatment (p < 0.0001), thus confirming their antioxidant activity as well as their ability in stimulating osteoblast function, mostly when genistein and lycopene were used in association. The combined treatment of genistein and lycopene improved the bone damage induced by glucocorticoids and significantly restored the normal architecture of bones as well as adequate interconnectivity of bone trabeculae, thus increasing bone mineral density parameters. The obtained data demonstrated that genistein and lycopene but in particular their association might prevent GC’s adverse effects, thus stimulating bone formation and reducing bone resorption, improving bone structure and microarchitecture, through different molecular pathways, such as the Wnt/β-catenin and the Nrf-2 signaling.

Lycopene Improves Bone Quality and Regulates AGE/RAGE/NF-кB Signaling Pathway in High-Fat Diet-Induced Obese Mice

Objective. This study was aimed at examining the effects of lycopene on bone metabolism in high-fat diet (HFD)- induced obese mice and to identify the potential underlying mechanisms. Methods. Mice were fed a HFD for 12 weeks and then continue with or without lycopene intervention (15 mg/kg) for additional 10 weeks. The effects of lycopene on blood glucose and lipid metabolism, as well as serum levels of total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and malondialdehyde (MDA) were determined by biochemical assays. Bone histomorphological features and osteoclast activity were assessed by hematoxylin/eosin and tartrate-resistant acid phosphatase staining. Bone microstructure at the proximal tibial metaphysis and diaphysis was determined by microcomputed tomography. Tibial biomechanical strength and material profiles were measured by a three-point bending assay and Fourier transform infrared spectroscopy. Protein expressions involved in the AGE/RAGE/NF-кB signaling pathway were determined by western blot and/or immunohistochemical staining. Results. Lycopene consumption reduced body weight gain and improved blood glucose and lipid metabolism in HFD-induced obese mice. In addition, lycopene treatment preserved bone biomechanical strength, material profiles, and microarchitecture in obese mice. Moreover, these alterations were associated with an increase in serum levels of T-AOC and SOD, and a decline in serum levels of MDA, as well as a reduction of AGEs, RAGE, cathepsin K, and p-NF-кBp65 and NF-кBp65 expressions in the femurs and tibias of obese mice. Conclusion. Lycopene may improve bone quality through its antioxidant properties, which may be linked with the regulation of the AGE/RAGE/NF-кB signaling pathway in obese mice. These results suggest that lycopene consumption may be beneficial for the management of obesity-induced osteoporosis.

Potential Role of Lycopene in the Prevention of Postmenopausal Bone Loss: Evidence from Molecular to Clinical Studies

Osteoporosis is a metabolic bone disease characterized by reduced bone mineral density, which affects the quality of life of the aging population. Furthermore, disruption of bone microarchitecture and the alteration of non-collagenous protein in bones lead to higher fracture risk. This is most common in postmenopausal women. Certain medications are being used for the treatment of osteoporosis; however, these may be accompanied by undesirable side effects. Phytochemicals from fruits and vegetables are a source of micronutrients for the maintenance of bone health. Among them, lycopene has recently been shown to have a potential protective effect against bone loss. Lycopene is a lipid-soluble carotenoid that exists in both all-trans and cis-configurations in nature. Tomato and tomato products are rich sources of lycopene. Several human epidemiological studies, supplemented by in vivo and in vitro studies, have shown decreased bone loss following the consumption of lycopene/tomato. However, there are still limited studies that have evaluated the effect of lycopene on the prevention of bone loss in postmenopausal women. Therefore, the aim of this review is to summarize the relevant literature on the potential impact of lycopene on postmenopausal bone loss with molecular and clinical evidence, including an overview of bone biology and the pathophysiology of osteoporosis.

Lycopene as a Natural Antioxidant Used to Prevent Human Health Disorders

Lycopene, belonging to the carotenoids, is a tetraterpene compound abundantly found in tomato and tomato-based products. It is fundamentally recognized as a potent antioxidant and a non-pro-vitamin A carotenoid. Lycopene has been found to be efficient in ameliorating cancer insurgences, diabetes mellitus, cardiac complications, oxidative stress-mediated malfunctions, inflammatory events, skin and bone diseases, hepatic, neural and reproductive disorders. This review summarizes information regarding its sources and uses amongst different societies, its biochemistry aspects, and the potential utilization of lycopene and possible mechanisms involved in alleviating the abovementioned disorders. Furthermore, future directions with the possible use of this nutraceutical against lifestyle-related disorders are emphasized. Its protective effects against recommended doses of toxic agents and toxicity and safety are also discussed.

Tangerine tomatoes: origin, biochemistry, potential health benefits and future prospects

BACKGROUND

Tomatoes and lycopene have been associated with the prevention of chronic diseases. Tetra-cis lycopene from tangerine tomatoes has been reported to be more bioavailable than the all-trans isomer found in red tomatoes. Therefore, tangerine tomatoes might contain superior health benefits compared to those of red tomatoes.

SCOPE AND APPROACH

This review focuses on the origin, biochemistry, nutritional composition, and potential health benefits of tangerine tomatoes, as well as their comparison with those of the red and high-β-carotene varieties. Information gathered from numerous studies on tomatoes, as well as conflicting perspectives, have been summarized to provide an unbiased review.

KEY FINDINGS AND CONCLUSION

The origin of tangerine tomatoes is disputable, but they were reportedly present from as early as 1934. The carotenoid biosynthesis pathway underlying the accumulation of tetra-cis lycopene in tangerine tomatoes has been well defined. However, the nutritional composition of tangerine tomatoes is not currently publicly available. The carotenoid composition of tangerine tomatoes is unique not only because of the presence of tetra-cis lycopene, but also due to the relatively high content of phytoene, phytofluene, ζ-carotene, and neurosporene relative to other tomato varieties. Although a few in vitro and in vivo studies have shown promising results, further studies are required to validate the health benefits of tangerine tomatoes. Furthermore, published data regarding the potential health benefits of tangerine tomatoes on cardiovascular and bone health is currently lacking even though red tomatoes have shown promise in these areas.

Carotenoids and Markers of Oxidative Stress in Human Observational Studies and Intervention Trials: Implications for Chronic Diseases

Carotenoids include C30, C40 and C50 terpenoid-based molecules, many of which constitute coloured pigments. However, >1100 of these are known to occur in nature and only about a dozen are known to play a role in our daily diet. Carotenoids have received much attention due to their proposed health benefits, including reducing the incidence of chronic diseases, such as cardiovascular disease and diabetes. Many of these diseases are characterized by chronic inflammation co-occurring with oxidative stress, characterized by, for example, enhanced plasma F2-isoprostane concentrations, malondialdehyde, and 8-hydroxyguanosine. Though carotenoids can act as direct antioxidants, quenching, for example, singlet oxygen and peroxide radicals, an important biological function appears to rest also in the activation of the body's own antioxidant defence system, related to superoxide-dismutase, catalase, and glutathione-peroxidase expression, likely due to the interaction with transcription factors, such as nuclear-factor erythroid 2-related factor 2 (Nrf-2). Though mostly based on small-scale and observational studies which do not allow for drawing conclusions regarding causality, several supplementation trials with isolated carotenoids or food items suggest positive health effects. However, negative effects have also been reported, especially regarding beta-carotene for smokers. This review is aimed at summarizing the results from human observational studies/intervention trials targeting carotenoids in relation to chronic diseases characterized by oxidative stress and markers thereof.

Lycopene presence in facial skin corneocytes and sebum and its association with circulating lycopene isomer profile: Effects of age and dietary supplementation

Lycopene is a dietary antioxidant known to prevent skin photodamage. This study aimed to examine age-dependent presence of this carotenoid on the surface of the facial skin and in the serum as well as to measure the same parameters during supplementation with lycopene. Serum samples and samples from facial skin surface were obtained from 60 young (under 25 years old) and 60 middle-aged (over 50 years old) volunteers. Similar samples were taken from 15 middle-aged subjects during 4-week supplementation with lycopene (7 mg/day). Serum lycopene levels and isomer profiles were analyzed by HPLC. Lycopene in desquamated corneocytes and the sebum from facial skin surface was determined using lycopene-specific fluorescent monoclonal antibodies. The results demonstrated that there was no age-related difference in serum lycopene levels, but a higher proportion of (all-E)-lycopene was detected in the "young" group (37.5% vs 26.2% in the "middle-aged" group; p < 0.0001). "Young" volunteers also had a higher lycopene level in both corneocytes (p = 0.0071) and the sebum (p = 0.0139) from the skin surface. Supplementation with lycopene resulted in a sharp increase of lycopene concentrations in both serum and skin surface samples. There was also a clear change in the pattern of lycopene isomers in the serum manifested by a significant increase in the proportion of (all-E)-lycopene (from 22.1% to 44.0% after supplementation, p < 0.0001). It can be concluded that dietary supplementation with lycopene results in its accumulation in the serum and skin. This process is accompanied by significant changes in the circulating lycopene isomer profile which becomes similar to that typical for young individuals.

Oxidative stress as a possible pathogenic cofactor of post-menopausal osteoporosis: Existing evidence in support of the axis oestrogen deficiency-redox imbalance-bone loss

Post-menopausal osteoporosis (PO) is one of the major health issues associated with menopause-related oestrogen withdrawal. Despite the intense research and the relevant progress achieved in the last two decades, the pathogenic mechanism underlying PO is still poorly understood. As a consequence of this gap in the knowledge, such disorder and the related complications are still difficult to be effectively prevented. A wealth of experimental and epidemiological/clinical evidence suggests that the endocrine change associated to menopausal transition might lead to a derangement of redox homeostasis, that is, the prelude to the health-threaten condition of oxidative stress (OxS). In turn, this (bio)chemical stress has been widely hypothesized to contribute, most likely in synergy with inflammation, to the development of menopause-related diseases, including PO. The main aim of this review is to discuss the current literature evidence on the association between post-menopausal oestrogen withdrawal, OxS and PO. It is also aimed to provide a critical overview of the most significant epidemiological studies on the effects of dietary antioxidants on bone health and to devise a strategy to overcome the limitations emerged and controversial results.

Effect of lycopene on titanium implant osseointegration in ovariectomized rats

Background

Lycopene prevents bone loss in osteopenic models. However, the role of lycopene in the success rate of dental implants under osteopenic conditions remains unknown. The aim of this study was to evaluate whether lycopene prevents delayed implant osseointegration in an ovariectomized (OVX) rat model.

Methods

Thirty female Sprague-Dawley rats were randomly divided into the following groups: OVX with vehicle (OVX group), OVX with lycopene (OVX + lycopene group) and sham-operated with vehicle (sham group). Twelve weeks after ovariectomy or sham operation, titanium implants were placed into the distal metaphysis of the bilateral femurs of each rat. These rats were subsequently gavaged with lycopene (50 mg/kg/day) or vehicle. After 12 weeks of gavage, all rats were sacrificed, and specimens were harvested. Sample osseointegration was evaluated by biomechanical testing, 3D micro-computed tomography (micro-CT) analysis and histomorphometric analysis.

Results

Compared with the OVX group, the OVX + lycopene group showed a 69.3% increase in the maximum push-out force (p < 0.01). Micro-CT data for the femurs in the OVX + lycopene group showed significantly higher bone volume, trabecular thickness and less trabecular space than did those in the OVX group. The bone area (BA) around the implant and bone contact (BC) with the implant were increased by 72.3% (p < 0.01) and 51.4% (p < 0.01) in the OVX + lycopene group, respectively, compared with those in the OVX group. There was no significant difference in the mechanical test, micro-CT scanning and histomorphometric data between the OVX + lycopene and sham groups (p > 0.05).

Conclusions

Lycopene improved implant osseointegration, fixation and bone formation under osteopenic conditions, suggesting that lycopene is a promising therapeutic agent to prevent delayed implant osseointegration and bone loss under osteopenic conditions.

Parthenolide inhibits hydrogen peroxide‑induced osteoblast apoptosis

Parthenolide is a natural product from the shoots of Tanacetum parthenium that has been demonstrated to have immunomodulatory effects in a number of diseases. The present study aimed to determine the effect and mechanism of parthenolide on the apoptotic ability of H2O2‑induced osteoblasts. Cell viability was analyzed with a MTT assay and the apoptotic rate was subsequently measured using flow cytometry. The activity of the antioxidative enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPX), and the serum marker enzymes alkaline phosphatase (ALP), malondialdehyde (MDA) and lactate dehydrogenase (LDH) was measured. Reverse transcription‑quantitative polymerase chain reaction and western blot analyses were performed to analyze the expression levels of osteogenesis and oxidative stress‑associated genes. The results indicated that parthenolide increased cell viability and inhibited the apoptosis of H2O2‑induced osteoblasts. Parthenolide decreased the levels of reactive oxygen species, MDA, LDH and ALP. SOD and GPX levels were increased by parthenolide in H2O2‑induced osteoblasts. This suggested that parthenolide may break the equilibrium state of oxidative stress and inhibit cellular apoptosis. Parthenolide additionally increased the expression levels of oxidative stress‑associated genes, including nuclear factor erythroid 2 like 2, hemeoxygenase‑1 and quinone oxidoreductase 1 in H2O2‑induced osteoblasts. Furthermore, parthenolide increased the expression of osteogenesis‑associated genes, including runt‑related transcription factor 2, osteopontin, osteocalcin and collagen 1 in H2O2‑inducedosteoblasts. Therefore, it was concluded that parthenolide may be used in the treatment of osteoporosis.

Modulation of human osteoclastogenesis and osteoblastogenesis by lycopene

Lycopene is a lipid-soluble pigment that is mainly found in tomato. It is the carotenoid that presents the highest antioxidant potential, and due to that, it has been implicated in a decrease of the risk of several oxidative-stress-related disorders, such as cancer, inflammatory diseases and osteoporosis. Nevertheless, at the present, there is no detailed information about how lycopene affects bone metabolism. The aim of the present work was to characterize the cellular and molecular effects of lycopene on human osteoclast and osteoblast differentiation and function. It was observed that lycopene, at levels found in plasma after the ingestion of lycopene-containing products, decreased osteoclast differentiation but did not affect cell density/survival; calcium-phosphate resorbing ability was also decreased. On the other hand, osteoblast proliferation (via a decrease on apoptosis) and differentiation were increased in the presence of lycopene. The observed effects in both cell types appeared to be related to significant changes in MEK signaling pathway, but also in protein kinase C pathway in osteoclasts and NFkB signaling in osteoblasts. In conclusion, lycopene appears to promote an anabolic state of bone metabolism, stimulating osteoblastogenesis and inhibiting osteoclastogenesis, which may contribute to the promotion of a proper health status of bone tissue. This information might be relevant for the prevention and delay in the progression of osteolytic bone conditions.

Carotenoids and risk of fracture: a meta-analysis of observational studies

To quantify the association between dietary and circulating carotenoids and fracture risk, a meta-analysis was conducted by searching MEDLINE and EMBASE databases for eligible articles published before May 2016. Five prospective and 2 case-control studies with 140,265 participants and 4,324 cases were identified in our meta-analysis. Among which 5 studies assessed the association between dietary carotenoids levels and hip fracture risk, 2 studies focused on the association between circulating carotenoids levels and any fracture risk. A random-effects model was employed to summarize the risk estimations and their 95% confidence intervals (CIs). Hip fracture risk among participants with high dietary total carotenoids intake was 28% lower than that in participants with low dietary total carotenoids (OR: 0.72; 95% CI: 0.51, 1.01). A similar risk of hip fracture was found for β-carotene based on 5 studies, the summarized OR for high vs. low dietary β-carotene was 0.72 (95% CI: 0.54, 0.95). However, a significant between-study heterogeneity was found (total carotene: I2 = 59.4%, P = 0.06; β-carotene: I2 = 74.4%, P = 0.04). Other individual carotenoids did not show significant associations with hip fracture risk. Circulating carotene levels had no significant association with any fracture risk, the pooled OR (95% CI) was 0.83 (0.59, 1.17). Based on the evidence from observational studies, our meta-analysis supported the hypothesis that higher dietary total carotenoids or β-carotene intake might be potentially associated with a low risk of hip fracture, however, future well-designed prospective cohort studies and randomized controlled trials are warranted to specify the associations between carotenoids and fracture.

Plasma Lycopene Is Associated with Pizza and Pasta Consumption in Middle-Aged and Older African American and White Adults in the Southeastern USA in a Cross-Sectional Study

BACKGROUND

The role of dietary lycopene in chronic disease prevention is not well known.

METHODS

This study examined intake of lycopene and other antioxidants from lycopene-rich foods (e.g., pizza and pasta) simultaneously with plasma levels of lycopene and other antioxidants in a representative cross-sectional sample (187 Blacks, 182 Whites, 40-79 years old) from the Southern Community Cohort Study (SCCS). The SCCS is an ongoing study conducted in populations at high risk for chronic diseases living in Southeastern United States. Dietary intake was assessed using a validated food frequency questionnaire (FFQ), and plasma levels of lycopene and other antioxidants were measured at baseline (2002-2005). The participants were classified into tertiles according to consumption of pizza and pasta food groups.

RESULTS

Lycopene dietary intake and plasma lycopene concentrations were significantly higher in the highest (tertile 3) compared to tertiles 1 and 2 (both P < 0.01). Total energy intake ranged from 1964.3 ± 117.1 kcal/day (tertile 1) to 3277.7 ± 115.8 kcal/day (tertile 3) (P<0.0001). After adjusting for age and energy intake, total dietary fat, saturated fatty acids, trans-fatty acids, and sodium intakes were significantly higher in tertile 3 than tertiles 2 and 1 (all P <0.01). Vitamin C intake was significantly lower in tertile 3 than tertiles 1 and 2 (P = 0.003). Except for γ-tocopherol being higher in tertile 3 than tertiles 1 and 2 (P = 0.015), the plasma concentrations of antioxidants were lower in tertile 3 than tertiles 1 and 2 (β-carotene, α-carotene, lutein and zeaxanthin, all P<0.05).

CONCLUSIONS

In the SCCS population, pizza and pasta were the main sources of dietary lycopene and their intake was associated with plasma lycopene concentration. Diets with frequent pizza and pasta consumption were high in energy, saturated fatty acids, trans-fatty acids, sodium and low in other antioxidants. Future studies of lycopene as a protective dietary factor against chronic disease should consider the overall nutritional quality of lycopene-containing foods.

Lycopene treatment against loss of bone mass, microarchitecture and strength in relation to regulatory mechanisms in a postmenopausal osteoporosis model

Lycopene supplementation decreases oxidative stress and exhibits beneficial effects on bone health, but the mechanisms through which it alters bone metabolism in vivo remain unclear. The present study aims to evaluate the effects of lycopene treatment on postmenopausal osteoporosis. Six-month-old female Wistar rats (n=264) were sham-operated (SHAM) or ovariectomized (OVX). The SHAM group received oral vehicle only and the OVX rats were randomized into five groups receiving oral daily lycopene treatment (mg/kg body weight per day): 0 OVX (control), 15 OVX, 30 OVX, and 45 OVX, and one group receiving alendronate (ALN) (2μg/kg body weight per day), for 12weeks. Bone densitometry measurements, bone turnover markers, biomechanical testing, and histomorphometric analysis were conducted. Micro computed tomography was also used to evaluate changes in microarchitecture. Lycopene treatment suppressed the OVX-induced increase in bone turnover, as indicated by changes in biomarkers of bone metabolism: serum osteocalcin (s-OC), serum N-terminal propeptide of type 1 collagen (s-PINP), serum crosslinked carboxyterminal telopeptides (s-CTX-1), and urinary deoxypyridinoline (u-DPD). Significant improvement in OVX-induced loss of bone mass, bone strength, and microarchitectural deterioration was observed in lycopene-treated OVX animals. These effects were observed mainly at sites rich in trabecular bone, with less effect in cortical bone. Lycopene treatment down-regulated osteoclast differentiation concurrent with up-regulating osteoblast together with glutathione peroxidase (GPx) catalase (CAT) and superoxide dismutase (SOD) activities. These findings demonstrate that lycopene treatment in OVX rats primarily suppressed bone turnover to restore bone strength and microarchitecture.

Dietary Approaches for Bone Health: Lessons from the Framingham Osteoporosis Study

Osteoporosis is characterized by systemic impairment of bone mass, strength, and microarchitecture, resulting in increased risk for fragility fracture, disability, loss of independence, and even death. Adequate nutrition is important in achieving and maintaining optimal bone mass, as well as preventing this debilitating disease. It is widely accepted that adequate calcium and vitamin D intake are necessary for good bone health; however, nutritional benefits to bone go beyond these two nutrients. This review article will provide updated information on all nutrients and foods now understood to alter bone health. Specifically, this paper will focus on related research from the Framingham Osteoporosis Study, an ancillary study of the Framingham Heart Study, with data on more than 5000 adult men and women.

The Effect of Tomato Juice Consumption on Antioxidant Status in Overweight and Obese Females

Tomatoes and their products are the main source of lycopene, a powerful potent antioxidant. Tomato products improve antioxidant defenses and reduce the risk of oxidative stress, at least partly, due to the presence of lycopene. Lycopene, as an antioxidant, induces the upregulation of antioxidant enzymes and reinforces the total enzyme capacity of the human body. Obesity is a chronic condition in which destructive mechanisms increase the reactive oxygen species and attenuation of antioxidant status. We hypothesized that the consumption of a lycopene-rich food would improve the antioxidant defense of women who were overweight or obese. A total of seventy-five overweight or obese female students of the Tehran University of Medical Sciences were enrolled and randomly allocated to one of two groups, intervention (n = 40) or control (n = 35), consuming 330 ml/d of tomato juice or water, respectively, for a 20-day period. At baseline and day 20, total antioxidant capacity and antioxidant enzyme activity (superoxide dismutase, glutathione peroxidase, and catalase) were analyzed using ELISA kits and spectrophotometric methods and then compared between the two groups. Lycopene consumption had no effect on these aforementioned variables. Therefore, it seems that more research with longer duration and more sensitive indicators will be required.

Tomato and tomato byproducts. Human health benefits of lycopene and its application to meat products: a review

During recent decades, the food industry, consumers, and regulatory authorities have developed a significant interest in functional foods because of their potential benefits for human health over and above their basic nutritional value. Tomato is the second most important vegetable crop in the world. The amount of the related wastes is estimated at up to 50,000 tons per year, representing a serious disposal problem with a consequent negative impact on the environment. Tomato byproducts contain a great variety of biologically active substances, principally lycopene, which have been demonstrated by in vitro and in vivo studies to possess antioxidant, hypolipidemic, and anticarcinogenic activities. The aim of this review is to present an overview of the functional and physiological properties of the principal bioactive compound present in tomato and tomato byproducts, lycopene, its addition to meat, and meat products.

Activation of AMPK protects against hydrogen peroxide-induced osteoblast apoptosis through autophagy induction and NADPH maintenance: new implications for osteonecrosis treatment?

Elevated hydrogen peroxide (H2O2) causes osteoblast dysfunction and apoptosis, serving as an important contributor to the development of osteonecrosis. Here we aimed to understand the role of AMP-activated protein kinase (AMPK) in the process. We observed a high level of AMPK activation in surgery isolated patients' osteonecrosis tissues. In cultured osteoblastoma MG63 cells, H2O2 stimulation induced significant AMPK activation, oxidative stress, cell death and apoptosis. Inhibition of AMPK by its inhibitor (compound C) or by shRNA-mediated knockdown dramatically enhanced H2O2-induced MG63 cell apoptosis, while over-expression of AMPK in HEK-293 cells alleviated H2O2-induced cell damage. These results confirmed that H2O2-activated AMPK is pro-cell survival. We observed that H2O2 induced protective autophagy in MG63 cells, and AMPK-dependent Ulk1 activation and mTORC1 (mTOR complex 1) inactivation might involve autophagy activation. Further, AMPK activation inhibited H2O2-induced oxidative stress, probably through inhibiting NADPH (nicotinamide adenine dinucleotide phosphate) depletion, since more NADPH depletion and oxidative stress were induced by H2O2 in AMPK deficient MG63 cells. Finally, we observed a significant AMPK activation in H2O2-treated primary cultured and transformed (MC3T3-E1) osteoblasts, and AMPK inhibitor compound C enhanced death by H2O2 in these cells. Based on these results, we concluded that H2O2-induced AMPK activation is pro-survival and anti-apoptosis in osteoblasts. Autophagy induction and NADPH maintenance are involved in AMPK-mediated pro-survival effects. AMPK might represent a novel molecular target for osteonecrosis treatment.

β-Adrenergic signaling stimulates osteoclastogenesis via reactive oxygen species

Sympathetic signaling regulates bone resorption through receptor activator of nuclear factor-κB ligand (RANKL) expression via the β-adrenergic receptor (β-AR) on osteoblasts. Reactive oxygen species (ROS) are known as one type of osteoclast regulatory molecule. Here we show that an antioxidant, α-lipoic acid (α-LA), treatment prevent the β-adrenergic signaling-induced bone loss by suppressing osteoclastogenesis, and sympathetic signaling directly regulates osteoclastogenesis through β2-AR expressed on osteoclasts via intracellular ROS generation. In an in vitro study, the β-AR agonist isoprenaline increased intracellular ROS generation in osteoclasts prepared from bone marrow macrophages (BBMs) and RAW 264.7 cells. Isoprenaline enhanced osteoclastogenesis through β2-AR expressed on BMMs and RAW 264.7 cells. The antioxidant α-LA inhibited isoprenaline-enhanced osteoclastogenesis. Isoprenaline increased the expression of osteoclast-related genes such as nuclear factor of activated T cells, cytoplasmic, calcineurin-dependent 1, tartrate-resistant acid phosphatase, and cathepsin K on osteoclasts. α-LA also inhibited isoprenaline-induced increases of these gene expressions. These in vitro results led to the hypothesis that β-adrenergic signaling directly stimulates osteoclastogenesis via ROS generation. In an in vivo study, isoprenaline treatment alone caused oxidative damage in local bone and reduced bone mass because of an increase in bone resorption, and, in α-LA-treated mice, isoprenaline did not increase tibial osteoclast number even though the RANKL-to-osteoprotegerin ratio increased. These in vitro and in vivo results indicate that β-adrenergic signaling, at least in part, directly stimulates osteoclastogenesis through β2-AR on osteoclasts via ROS generation.

Phytonutrients for bone health during ageing

Osteoporosis is a skeletal disease characterized by a decrease in bone mass and bone quality that predispose an individual to an increased risk of fragility fractures. Evidence demonstrating a positive link between certain dietary patterns (e.g. Mediterranean diet or high consumption of fruits and vegetables) and bone health highlights an opportunity to investigate their potential to protect against the deterioration of bone tissue during ageing. While the list of these phytonutrients is extensive, this review summarizes evidence on some which are commonly consumed and have gained increasing attention over recent years, including lycopene and various polyphenols (e.g. polyphenols from tea, grape seed, citrus fruit, olive and dried plum). Evidence to define a clear link between these phytonutrients and bone health is currently insufficient to generate precise dietary recommendations, owing to mixed findings or a scarcity in clinical data. Moreover, their consumption typically occurs within the context of a diet consisting of a mix of phytonutrients and other nutrients rather than in isolation. Future clinical trials that can apply a robust set of outcome measurements, including the determinants of bone strength, such as bone quantity (i.e. bone mineral density) and bone quality (i.e. bone turnover and bone microarchitecture), will help to provide a more comprehensive outlook on how bone responds to these various phytonutrients. Moreover, future trials that combine these phytonutrients with established bone nutrients (i.e. calcium and vitamin D) are needed to determine whether combined strategies can produce more robust effects on skeletal health.

Zinc inhibits H(2)O(2)-induced MC3T3-E1 cells apoptosis via MAPK and PI3K/AKT pathways

Zinc has been shown to increase bone mass and promote bone cell proliferation and differentiation. We, therefore, hypothesized that zinc might be cytoprotective for bone cells during oxidative stress. The cells were divided into H(2)O(2), zinc and zinc+H(2)O(2) groups. In the present study, zinc was found to inhibit H(2)O(2)-induced apoptosis in MC3T3-E1 cells, as shown by analysis of Annexin V/PI double staining. Western blot data showed that in zinc+H(2)O(2)-treated cells, zinc decreased the levels of AIF, Bax and active caspase-9 and -3, which are pro-apoptotic factors. And zinc inhibited release of cytochrome c from mitochondria to cytosol in zinc+H(2)O(2)-treated cells. Further investigation shows that protection is via activation of PI3K/Akt/mTor and MAPK /ERK pathways and inhibition of MAPK/P38 and MAPK/JNK pathways. Protecting osteoblast cells from oxidative damage presents a potential application in the treatment of osteoporosis.

Lycopene effects on serum mineral elements and bone strength in rats

This study investigated the beneficial effect of lycopene on bone biomarkers in ovariectomized (OVX) rats. Female Wistar rats were either sham operated or surgically ovariectomized and then fed with lycopene for 8 weeks. Serum Ca, P, alkaline phosphatase (ALP), interleukin 6 (IL-6) and bone gla protein (BGP) concentration was significantly higher in the untreated OVX group compared with that of the sham group, whereas serum estrogen levels were lower. Bone mineral density (BMD), BMD/wt, bone mineral content (BMC), BMC/wt values, maximum load, stiffness, energy and maximum stress were significantly lower in the untreated OVX group compared with that of the sham group. Administration of lycopene (20, 30 and 40 mg/kg b.w.) for 8 weeks significantly decreased serum Ca, P, ALP, and IL-6 concentration, and enhanced serum estrogen level, BMD, BMD/wt, BMC, BMC/wt values, maximum load, stiffness, energy and maximum stress in lycopene-treated OVX groups. In conclusion, the consumption of lycopene may have the most protective effect on bone in OVX rats.

The protective effect of calcium on bone mass in postmenopausal women with high selenium intake

OBJECTIVE

Nutritional factors, especially the two essential nutrients calcium and vitamin D, have been shown to play an important role in bone health. We wanted to determine the possible protective effect of calcium intake in adequate amounts on bone mass as assessed by quantitative ultrasound in postmenopausal women who also have a high intake of selenium.

SETTING

Health district of Cáceres, Spain. PARTICIPANTS AND STUDY DESIGN: 335 postmenopausal women aged 60.9 (SD = 8.1) years. Women were stratified based on the vitamin D, vitamin E, calcium intake and the calcium/protein and calcium/phosphorous index.

MEASUREMENTS

Bone status (Ad-SoS measured at the phalanges) was assessed with an ultrasound device model DBM Sonic 1200R. Food intake was quantified using dietetic scales, measuring cups, and spoons based on 7 days of diet records. Urine samples were collected the morning of testing after an overnight fast. Venous blood samples for the hematological and biochemical studies were also obtained in the fasting state.

RESULTS

In the group of women with Ca intake < 800 mg / d we found a significant and negative relationship between Ad-SoS with age (β= -4.020, F = 23.327) and selenium intake (β = -0.419, F = 10.067), as well as a positive relationship with Ca intake (β= 0.104 and F = 7.084) (p <0.0001 in all). In the group of women with Ca intake > 800 mg / d, age has a significant and negative relationship (β = -4.829 and F = 106.745), whereas folic acid intake has a significant and positive relationship (β = 0.047 and F = 5.858) (p <0.0001 in both).

CONCLUSION

Elevated selenium intake negatively affects bone mass measurements in postmenopausal women over the age of 51 but only if calcium intake is also less than 800 mg / day. When calcium intake is greater than 800 mg/day, selenium did not appear to affect bone mass.