Dietary Polyphenols, Berries, and Age-Related Bone Loss: A Review Based on Human, Animal, and Cell Studies

Increased Osteoblastic and Osteocytic in Vitro Cell Viability by Yerba Mate (Ilex paraguariensis)

BACKGROUND

Yerba mate (YM, Ilex paraguariensis) consumption beneficially affects the bones. However, whether YM components exert their effect on bone cells directly remains elusive.

METHODS

We evaluated how main YM components affect osteoblastic (MC3T3-E1) and osteocytic (MLO-Y4) cells in vitro when administered separately or in an aqueous extract. MC3T3-E1 and MLO-Y4 cells were exposed to three different experimental conditions: (1) Caffeine, chlorogenic acid, and their combinations; (2) Caffeine, rutin, and their combinations; (3) Aqueous YM extract.

RESULTS

All polyphenol and caffeine concentrations as well as that of their tested combinations significantly increased MC3T3-E1 cell viability from 16.6% to 34.8% compared to the control. In MLO-Y4 cells, the lowest rutin and the two highest caffeine concentrations significantly increased cell viability by 11.9, 14.9, and 13.7%, respectively. While rutin and caffeine combinations tended to increase MLO-Y4 cell viability, different chlorogenic acid and caffeine combinations did not affect it. Finally, the aqueous YM extract significantly increased MLO-Y4, MC3T3-E1, and differentiated MC3T3-E1 cell viability compared to the control without treatment.

CONCLUSIONS

YM components (rutin, chlorogenic acid, and caffeine) positively affected bone cells, mainly pre-osteoblast cells. Moreover, the aqueous YM extract significantly increased MLO-Y4, MC3T3-E1, and differentiated MC3T3-E1 cell viabilities indicating an additional relevant nutritional property of YM infusion. Further studies would be required to elucidate the underlying effector mechanism of YM on the bones and its relationship with previously described in vivo positive effects.

Differential Effects of Endurance Exercise on Musculoskeletal and Hematopoietic Modulation in Old Mice

One of the most important strategies for successful aging is exercise. However, the effect of exercise can differ among individuals, even with exercise of the same type and intensity. Therefore, this study aims to confirm whether endurance training (ETR) has the same health-promoting effects on the musculoskeletal and hematopoietic systems regardless of age. Ten weeks of ETR improved endurance exercise capacity, with increased skeletal muscle mitochondrial enzymes in both young and old mice. In addition, age-related deterioration of muscle fiber size and bone microstructure was improved. The expression levels of myostatin, muscle RING-finger protein-1, and muscle atrophy F-box in skeletal muscle and peroxisome proliferator-activated receptor-γ in the femur increased with age but decreased after ETR. ETR differentially modulated hematopoietic stem cells (HSCs) depending on age; ETR induced HSC quiescence in young mice but caused HSC senescence in old mice. ETR has differential effects on modulation of the musculoskeletal and hematopoietic systems in old mice. In other words, endurance exercise is a double-edged sword for successful aging, and great effort is required to establish exercise strategies for healthy aging.

The entrancing role of dietary polyphenols against the most frequent aging-associated diseases

Aging, a fundamental physiological process influenced by innumerable biological and genetic pathways, is an important driving factor for several aging-associated disorders like diabetes mellitus, osteoporosis, cancer, and neurodegenerative diseases including Alzheimer's and Parkinson's diseases. In the modern era, the several mechanisms associated with aging have been deeply studied. Treatment and therapeutics for age-related diseases have also made considerable advances; however, for the effective and long-lasting treatment, nutritional therapy particularly including dietary polyphenols from the natural origin are endorsed. These dietary polyphenols (e.g., apigenin, baicalin, curcumin, epigallocatechin gallate, kaempferol, quercetin, resveratrol, and theaflavin), and many other phytochemicals target certain molecular, genetic mechanisms. The most common pathways of age-associated diseases are mitogen-activated protein kinase, reactive oxygen species production, nuclear factor kappa light chain enhancer of activated B cells signaling pathways, metal chelation, c-Jun N-terminal kinase, and inflammation. Polyphenols slow down the course of aging and help in combatting age-linked disorders. This exemplified in the form of clinical trials on specific dietary polyphenols in various aging-associated diseases. With this context in mind, this review reveals the new insights to slow down the aging process, and consequently reduce some classic diseases associated with age such as aforementioned, and targeting age-associated diseases by the activities of dietary polyphenols of natural origin.

Molecular bases for the use of functional foods in the management of healthy aging: Berries, curcumin, virgin olive oil and honey; three realities and a promise

As the number of older people has grown in recent decades, the search for new approaches to manage or delay aging is also growing. Among the modifiable factors, diet plays a crucial role in healthy aging and in the prevention of age-related diseases. Thus, the interest in the use of foods, which are rich in bioactive compounds such as functional foods with anti-aging effects is a growing market. This review summarizes the current knowledge about the molecular mechanisms of action of foods considered as functional foods in aging, namely berries, curcumin, and virgin olive oil. Moreover, honey is also analyzed as a food with well-known healthy benefits, but which has not been deeply evaluated from the point of view of aging. The effects of these foods on aging are analyzed from the point of view of molecular mechanisms including oxidative stress, mitochondrial dysfunction, inflammation, genomic stability, telomere attrition, cellular senescence, and deregulated nutrient-sensing. A comprehensive study of the scientific literature shows that the aforementioned foods have demonstrated positive effects on certain aspects of aging, which might justify their use as functional foods in elderly. However, more research is needed, especially in humans, designed to understand in depth the mechanisms of action through which they act.

Storage Quality Changes in Craft and Industrial Blueberry, Strawberry, Raspberry and Passion Fruit-Mango Sorbets

Sorbets are a popular dessert, especially during hot summer days. They can also have health-promoting qualities, mainly due to the nutritional value of the fruit from which they are made. The production technology can also have an impact on the final nutritional quality of the sorbets. This paper presents a comparative assessment of the quality of industrial fruit sorbets and their craft analogs. Sorbets with the following flavors were selected for the research: blueberry, strawberry, raspberry, and passion fruit with mango. An organoleptic evaluation was performed, and the overrun, melting resistance, active acidity (pH), color in the CIE Lab system, antiradical activity (DDPH method), and content of vitamin C and total polyphenols were determined. The research revealed the differences between sorbets produced from different fruits as well as the differences depending on the production method between products made of the same type of fruit. Craft sorbets were found to be better than industrial sorbets, and storage time had a significant effect on the sorbets' quality. In terms of organoleptic characteristics, craft mango-passion fruit sorbet turned out to be the best; in terms of antioxidant properties, craft raspberry and strawberry sorbets were the best, and these two sorbets also showed good, stable overrun and melting resistance values during storage.

Pharmacology-based molecular docking of 4-methylcatechol and its role in RANKL-mediated ROS/Keap1/Nrf2 signalling axis and osteoclastogenesis

4-Methylcatechol (4-MC) is an agonist of various neurotrophic factors, which can upregulate the expression of Heme oxygenase 1 (HO-1) protein by activating nuclear factor erythroid 2-related factor 2 (Nrf2), thereby inhibiting oxidative stress-induced neural stem cell death. During RANKL-stimulated osteoclast differentiation, intracellular reactive oxygen species (ROS) levels were increased. Nonetheless, the effect of 4-MC on osteoclast formation and bone resorption function has not been researched. In this study, we investigated the effect of HO-1 upregulation by 4-MC on RANKL-induced osteoclastogenesis and explored the molecular mechanism of HO-1 upregulation by 4-MC. We found that the small molecule compound 4-MC could bind to Keap1 amino acid residue of glycine GLY 367, isoleucine ILE 559 and valine VAL 606, with a predicted binding energy of -4.99 kcal/mol. 4-MC was found to inhibit osteoclast differentiation in vitro by activating Nrf2 to scavenge ROS, inhibiting NF-κB phosphorylation, and alleviating osteoporosis in ovariectomized (OVX) mice. Taken together, 4-MC reduces ROS by inhibiting Keap1, thereby preventing OVX-induced bone loss.

The Effect of Apple-Derived Nanovesicles on the Osteoblastogenesis of Osteoblastic MC3T3-E1 Cells

Osteoporosis is characterized by low bone mass and elevated structural deterioration of the bone tissue, resulting in bone weakness with an increased risk of fracture. Considering biological activities of various phytochemicals extracted from apples, we herein demonstrated the potential antiosteoporotic effects of apple-derived nanovesicles (apple NVs) using osteoblastic MC3T3-E1 cells. Apple NVs significantly stimulated the growth of MC3T3-E1 cells. The cellular alkaline phosphatase (ALP) activity was significantly upregulated in the 5 μg/mL apple NVs-treated group. In addition, the concentrarion of mineralized nodules was significantly increased in the apple NVs-treated groups. Furthermore, apple NVs increased the expression of the genes and proteins associated with osteoblast growth and differentiation, such as Runx2, ALP, OPN, and BMP2/4, which further activated ERK- and JNK-related mitogen-activated protein kinase signaling. These results demonstrate that apple NVs have a potential to prevent osteoporosis by promoting osteoblastogenesis in osteoblastic MC3T3-E1 cells through regulating the BMP2/Smad1 pathways.

Osteogenic Effect of Fisetin Doping in Bioactive Glass/Poly(caprolactone) Hybrid Scaffolds

Treating large bone defects or fragile patients may require enhancing the bone regeneration rate to overcome a weak contribution from the body. This work investigates the osteogenic potential of nutrient fisetin, a flavonoid found in fruits and vegetables, as a doping agent inside the structure of a SiO₂-CaO bioactive glass-poly(caprolactone) (BG-PCL) hybrid scaffold. Embedded in the full mass of the BG-PCL hybrid during one-pot synthesis, we demonstrate fisetin to be delivered sustainably; the release follows a first-order kinetics with active fisetin concentration being delivered for more than 1 month (36 days). The biological effect of BG-PCL-fisetin-doped scaffolds (BG-PCL-Fis) has been highlighted by in vitro and in vivo studies. A positive impact is demonstrated on the adhesion and the differentiation of rat primary osteoblasts, without an adverse cytotoxic effect. Implantation in critical-size mouse calvaria defects shows bone remodeling characteristics and remarkable enhancement of bone regeneration for fisetin-doped scaffolds, with the regenerated bone volume being twofold that of nondoped scaffolds and fourfold that of a commercial trabecular bovine bone substitute. Such highly bioactive materials could stand as competitive alternative strategies involving biomaterials loaded with growth factors, the use of the latter being the subject of growing concerns.

Effect of Dietary Polyphenols on Osteoarthritis—Molecular Mechanisms

Osteoarthritis is a common crippling and degenerative disease resulting in irreversible functional changes due to damage of the cartilage and other tissues of the joint. With limited safe and effective pharmaceutical treatments, the demand and use for alternative therapeutic approaches with symptomatic relief for OA patients have increased. Clinical, pre-clinical, and in vitro studies have demonstrated that polyphenols can exert pain-relieving symptoms coupled with increased functional capacity in OA models. This review will highlight studies carried out in the last five years to define the efficacies and underlying mechanisms in polyphenols such as quercetin, resveratrol, curcumin, epigallocatechin-3-gallate, rosmarinic acid, genistein, ginger, berries, silver fir, pine bark, and Boswellia. Most of these studies indicate that polyphenols exhibit their beneficial roles through regulating changes at the biochemical and molecular levels, inducing or inhibiting various signaling pathways related to inflammation and oxidative stress. Polyphenols have also been implicated in modulating microRNA at the posttranscriptional level to counteract OA pathogenesis.

The Effects of Polyphenol, Tannic Acid, or Tannic Acid in Combination with Pamidronate on Human Osteoblast Cell Line Metabolism

Background: This study investigates the effect of tannic acid (TA) combined with pamidronate (PAM) on a human osteoblast cell line. Methods: EC₅₀ for TA, PAM, and different combination ratios of TA and PAM (25:75, 50:50, 75:25) were measured by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. The combination index value was utilized to analyze the degree of drug interaction, while trypan blue assay was applied to analyze the cells proliferation effect. The mineralization and detection of bone BSP and Osx genes were determined via histochemical staining and PCR test, respectively. Results: The EC₅₀ of osteoblasts treated with TA and a 75:25 ratio of TA and PAM were more potent with lower EC₅₀ at 0.56 µg/mL and 0.48 µg/mL, respectively. The combination of TA and PAM (75:25) was shown to have synergistic interaction. On Day 7, both TA and PAM groups showed significantly increased proliferation compared with control and combination groups. On Day 7, both the TA and combination-treated groups demonstrated a higher production of calcium deposits than the control and PAM-treated groups. Moreover, on Day 7, the combination-treated group showed a significantly higher expression of BSP and Osx genes than both the TA and PAM groups. Conclusion: Combination treatment of TA and PAM at 75:25 ameliorated the highest enhancement of osteoblast proliferation and mineralization as well as caused a high expression of BSP and Osx genes.

Green-Synthesized Magnesium Hydroxide Nanoparticles Induced Osteoblastic Differentiation in Bone Co-Cultured Cells

In this work, magnesium hydroxide NPs were synthesized using water (Mg(OH)₂ NPs) or a rose hip (RH) extract (Mg(OH)₂RH NPs) and tested for the bone cells’ effects in co-cultured osteoblastic and osteoclastic cells, using a Transwell^® insert system, allowing reciprocal cell paracrine interactions. Behavior of each cell population was characterized for typical phenotype markers, at days 1 and 6. Cell cultures treated with osteogenic/osteoclastogenic inducers were used as positive control of cell differentiation. The NPs presented a round shape morphology with an average diameter ~90 nm (Mg(OH)₂ NPs) and below 10 nm (Mg(OH)₂RH NPs. Both NPs induced osteoblastic and osteoclastic behavior similarly to that observed in induced osteoblastic and osteoclastic cultures (positive controls). Differences between the two types of particles were evident at the gene expression level. Compared to Mg(OH)₂ NPs, the green-synthesized NPs greatly increased the expression of osteoblastic genes coding for the early markers ALP and collagen type 1 and the later transcription factor osterix, while decreasing the expression of osteoclastogenic genes, namely the essential transcription factor NFATC1, TRAP and the genes coding for the functional markers CA2 and CTSK. Overall, a positive added effect could be hypothesized for Mg(OH)₂RH NPs with potential usefulness to promote bone formation in regenerative applications.

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.

Polyphenols Modulating Effects of PD-L1/PD-1 Checkpoint and EMT-Mediated PD-L1 Overexpression in Breast Cancer

Investigating dietary polyphenolic compounds as antitumor agents are rising due to the growing evidence of the close association between immunity and cancer. Cancer cells elude immune surveillance for enhancing their progression and metastasis utilizing various mechanisms. These mechanisms include the upregulation of programmed death-ligand 1 (PD-L1) expression and Epithelial-to-Mesenchymal Transition (EMT) cell phenotype activation. In addition to its role in stimulating normal embryonic development, EMT has been identified as a critical driver in various aspects of cancer pathology, including carcinogenesis, metastasis, and drug resistance. Furthermore, EMT conversion to another phenotype, Mesenchymal-to-Epithelial Transition (MET), is crucial in developing cancer metastasis. A central mechanism in the upregulation of PD-L1 expression in various cancer types is EMT signaling activation. In breast cancer (BC) cells, the upregulated level of PD-L1 has become a critical target in cancer therapy. Various signal transduction pathways are involved in EMT-mediated PD-L1 checkpoint overexpression. Three main groups are considered potential targets in EMT development; the effectors (E-cadherin and Vimentin), the regulators (Zeb, Twist, and Snail), and the inducers that include members of the transforming growth factor-beta (TGF-β). Meanwhile, the correlation between consuming flavonoid-rich food and the lower risk of cancers has been demonstrated. In BC, polyphenols were found to downregulate PD-L1 expression. This review highlights the effects of polyphenols on the EMT process by inhibiting mesenchymal proteins and upregulating the epithelial phenotype. This multifunctional mechanism could hold promises in the prevention and treating breast cancer.

The dietary anthocyanin delphinidin prevents bone resorption by inhibiting Rankl-induced differentiation of osteoclasts in a medaka (Oryzias latipes) model of osteoporosis

The anthocyanin delphinidin is a natural compound found as water-soluble pigment in coloured fruits and berries. Anthocyanin-rich diets have been proposed to have bone protective effects in humans and mice, but the underlying mechanisms remain unclear. In this study, we used a medaka (Oryzias latipes) osteoporosis model to test the effects of delphinidin on bone cells in vivo. In this model, inducible transgenic expression of receptor-activator of NF-kβ ligand (Rankl) leads to ectopic formation of osteoclasts and excessive bone resorption, similar to the situation in human osteoporosis patients. Using live imaging in medaka bone reporter lines, we show that delphinidin significantly reduces the number of osteoclasts after Rankl induction and protects bone integrity in a dose-dependent manner. Our in vivo findings suggest that delphinidin primarily affects the de novo differentiation of macrophages into osteoclasts rather than the recruitment of macrophages to sites of bone resorption. For already existing osteoclasts, delphinidin treatment affected their morphology, leading to fewer protrusions and a more spherical shape. Apoptosis rates were not increased by delphinidin, suggesting that osteoclast numbers were reduced primarily by impaired differentiation from macrophage progenitors and reduced maintenance of pre-existing osteoclasts. Importantly, and in contrast to previously reported cell culture experiments, no effect of delphinidin on osteoblast differentiation and distribution was observed in medaka in vivo. Our study is the first report on the effects of delphinidin on bone cells in fish embryos, which are a unique model system for compound testing that is suitable for live imaging of bone cell behaviour in vivo.

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.

Anthocyanins, Microbiome and Health Benefits in Aging

The percentage of individuals over the age of 60 is projected to reach 22% by 2050; chronic diseases associated with aging can present challenges for these individuals. Anthocyanins and the gut microbiome have each been studied as independent influencers of health. Both these factors have shown to have a positive effect on cardiovascular and bone health in individuals, as well as on the prevention or treatment of certain forms of cancers. Anthocyanins have shown to modulate the composition of the gut microbiome and may have overlapping mechanisms in the prevention and treatment of cardiovascular disease, cancer, neurodegenerative disorders and aging-associated bone loss. These health outcomes are responsible for the hospitalization and deaths of millions of Americans every year and they cost the United States billions of dollars each year to maintain, prevent and treat. Alternative methods of treatment and prevention are desired since conventional methods (surgical and pharmacological methods, physical therapy, etc.) can be costly and have significant side effects; evidence suggests that anthocyanins and the gut microbiome may be potential avenues for this. This review evaluates the findings of existing literature on the role of anthocyanins and the gut microbiome on health and their potential as a natural therapeutic agent or a target organ to provide an alternative to the conventional methods of disease prevention and treatment.

Flavonoids as natural phenolic compounds and their role in therapeutics: an overview

Background

Natural plants and plant-derived formulations have been used by mankind from the ancient period of time. For the past few years, many investigations elaborated the therapeutic potential of various secondary chemicals present in the plants. Literature revealed that the various secondary metabolites, viz. phenolics and flavonoids, are responsible for a variety of therapeutic action in humans.

Main body

In the present review, an attempt has been made to compile the exploration of natural phenolic compounds with major emphasis on flavonoids and their therapeutic potential too. Interestingly, long-term intake of many dietary foods (rich in phenolics) proved to be protective against the development and management of diabetes, cancer, osteoporosis, cardiovascular diseases and neurodegenerative diseases, etc.

Conclusion

This review presents an overview of flavonoid compounds to use them as a potential therapeutic alternative in various diseases and disorders. In addition, the present understanding of phenolics and flavonoids will serve as the basis for the next scientific studies.

Viburnum opulus L.-A Review of Phytochemistry and Biological Effects

Viburnum opulus (VO) is a valuable decorative, medicinal, and food plant. This deciduous shrub is found in natural habitats in Europe, Russia, and some regions in North Africa and North Asia. The VO is traditionally used to treat aliments such as cough, colds, tuberculosis, rheumatic aches, ulcers, stomach, and kidney problems, among others. Many of the health-promoting properties of VO are associated with antioxidant activity, which has been demonstrated in both in vitro and in vivo studies. The results of in vitro studies show the antimicrobial potential of VO, especially against Gram-positive bacteria. In cell-based studies, VO demonstrated anti-inflammatory, anti-obesity, anti-diabetic, osteogenic, cardio-protective, and cytoprotective properties. The applicability of VO in the treatment of urinary tract diseases, endometriosis, and some cancers has been confirmed in in vivo studies. The health benefits of VO result from the presence of bioactive components such as phenolic compounds, vitamin C, carotenoids, iridoids, and essential oils. The aim of this review is to present an overview of the botanical characteristics, chemical compositions, including bioactive compounds, and pro-health properties of VO different morphological parts.

Zingiber officinale Roscoe Prevents DNA Damage and Improves Muscle Performance and Bone Integrity in Old Sprague Dawley Rats

Age-related loss of skeletal muscle mass and strength or sarcopenia is attributed to the high level of oxidative stress and inadequate nutritional intake. The imbalance in oxidative status with increased production of free radicals results in damage to the DNA which leads to cell dysfunction. This study aimed to determine the effect of Zingiber officinale Roscoe (ginger) on muscle performance and bone integrity in Sprague Dawley (SD) rats. SD rats aged three (young), nine (adult), and twenty-one (old) months old were treated with either distilled water or ginger extract at a concentration of 200 mg/kg body weight (BW) daily for 3 months via oral gavage. Muscle performance was assessed at 0, 1, 2, and 3 months of treatment by measuring muscle strength, muscle function, and bone integrity while DNA damage was determined by comet assay. Muscle cell histology was analyzed by hematoxylin and eosin (H&E) staining. Young and adult ginger-treated rats showed a significant improvement in muscle strength after 3 months of supplementation. Bone mineral density (BMD) and bone mineral content (BMC) were increased while fat free mass (FMM) was decreased after 3 months of ginger supplementation in young rats but not changed in adult and old ginger supplemented groups. Interestingly, supplementation of ginger for 3 months to the old rats decreased the level of damaged DNA. Histological findings showed reduction in the size of muscle fibre and fascicles with heterogenous morphology of the muscle fibres indicating sarcopenia was evident in old rats. Treatment with ginger extract improved the histological changes even though there was evidence of cellular infiltration (mild inflammation) and dilated blood vessels. In conclusion, Z. officinale Roscoe prevents DNA damage and improves muscle performance and bone integrity in SD rats indicating its potential in alleviating oxidative stress in ageing and thus delaying sarcopenia progression.

Children's liking and wanting of foods vary over multiple bites/sips of consumption: A case study of foods containing wild blueberry powder in the amounts targeted to deliver bioactive phytonutrients for children

To encourage children to frequently consume wild blueberries as part of their dietary patterns, incorporating blueberry powder into specific foods may be an effective strategy. Thus, it is important to determine appropriate types of food products that both minimize food processing-induced loss of beneficial components of blueberries (e.g., anthocyanins) and satisfy at the same time both nutritional and sensory aspects. For clinical studies assessing the health benefits of blueberry-containing food samples, it would be important to ensure children consume the entire portion of the test samples. This study, therefore, aimed at determining how sensory acceptability (liking) and psychological reward (wanting) of wild blueberry-based foods vary over multiple steps of ad libitum consumption: appearance, first bite/sip, half bite/sip, and full consumption. Five different types of foods containing the targeted amount of wild blueberry powder were prepared for sensory testing (oatmeal bar, beverage, ice pop, gummy, and cookie), and the residual amounts of total anthocyanin and chlorogenic acid were measured to confirm levels targeted to deliver bioactive amounts of these phytochemicals. Results showed that while overall liking and desire to eat did not differ among the five samples at the appearance and first bite/sip steps, they differed significantly at the end of consumption. Although children liked and wanted to consume the cookies more when compared to beverages, ice pops, and/or gummies, total anthocyanin contents were lower in cookies and gummies than in wild blueberry powder, beverage, and ice pop samples. Notably, the oatmeal bars with significant amounts of total anthocyanin and chlorogenic acid did not significantly differ from the cookies with respect to overall liking, desire to eat, and the amount consumed. In conclusion, this study shows that sensory evaluation using multiple bites/sips of ad libitum food consumption, along with a measurement of beneficial compounds, is efficient in determining appropriate vehicles for clinical studies of wild blueberry-containing foods.

A 90 day oral toxicity study of blueberry polyphenols in ovariectomized sprague-dawley rats

Regular consumption of polyphenol-rich fruits and vegetables is associated with beneficial health outcomes. To increase polyphenol intakes, consumers are increasingly using herbal and botanical dietary supplements containing concentrated polyphenol extracts. However, the safety of this consumption modality has not been vetted. To address this, ovariectomized Sprague-Dawley (OVX-SD) rats were orally gavaged with purified blueberry polyphenols at 0-1000 mg total polyphenols/kg bw/d for 90d. No differences in behavior, body weight, or food consumption were observed. No tumors or macroscopic changes were observed, and histopathological analyses showed no differences among groups. Although several statistically significant differences between treatment and control groups were observed in urine (color and pH) and blood (monocyte count, total cholesterol, and chloride ion concentration) analyses, these parameters were within normal ranges and not considered biologically significant. Intestinal permeability assessed via FITC-dextran showed increased intestinal permeability in the highest dose, though no morphological differences were found throughout the gastrointestinal tract. Given the lack of other systemic changes, this finding is likely of minimal physiological importance. These results indicate a NOAEL for blueberry polyphenols in OVX-SD rats is ≥ 1000 mg total polyphenols/kg bw/d, which translates to a 70 kg human consuming ~10 g polyphenols. Keywords: Blueberry, Polyphenol, Sub-chronic toxicity.

Blueberry Juice Antioxidants Protect Osteogenic Activity against Oxidative Stress and Improve Long-Term Activation of the Mineralization Process in Human Osteoblast-Like SaOS-2 Cells: Involvement of SIRT1

Diets rich in fruits and vegetables with many antioxidants can be very important in the prevention and treatment of osteoporosis. Studies show that oxidative stress, often due to lack of antioxidants, is involved in alteration of bone remodeling and reduction in bone density. This study demonstrates in human osteoblast-like SaOS-2 cells that blueberry juice (BJ), containing 7.5 or 15 μg∙mL^-1 total soluble polyphenols (TSP), is able to prevent the inhibition of osteogenic differentiation and the mineralization process due to oxidative stress induced by glutathione depletion. This situation mimics a metabolic condition of oxidative stress that may occur during estrogen deficiency. The effect of BJ phytochemicals occurs through redox- and non-redox-regulated mechanisms. BJ protects from oxidative damage factors related to bone remodeling and bone formation, such as alkaline phosphatase and Runt-related transcription factor 2. It upregulates these factors by activation of sirtuin type 1 deacetylase expression, a possible molecular target for anti-osteoporotic drugs. Quantitative analysis of TSP in BJ shows high levels of anthocyanins with high antioxidant capacity and bioavailability. These novel data may be important to elucidate the molecular and cellular beneficial effects of blueberry polyphenols on bone regeneration, and they suggest their use as a dietary supplement for osteoporosis prevention and therapies.

A Delphinidin-Enriched Maqui Berry Extract Improves Bone Metabolism and Protects against Bone Loss in Osteopenic Mouse Models

In our previous investigation, delphinidin, one of the most abundant anthocyanins found in vegetables and berry fruits, had been shown to inhibit osteoclasts and prevent bone loss in mouse models of osteoporosis. In the present study, we investigated whether a delphinidin glycoside-enriched maqui berry extract (MBE, Delphinol^®) exhibits beneficial effects on bone metabolism both in vitro and in vivo. MBE stimulated the osteoblastic differentiation of MC3T3-E1 cells, as indicated by enhanced mineralized nodule formation, and increased alkaline phosphatase activity, through the upregulation of bone morphogenetic protein 2 (Bmp2), runt-related transcription factor 2 (Runx2), osterix (Osx), osteocalcin (Ocn), and matrix extracellular phosphoglycoprotein (Mepe) mRNA expression. Immunostaining and immunoprecipitation assays demonstrated that MBE suppressed NF-κB transnucleation through acting as a superoxide anion/peroxynitrite scavenger in MC3T3-E1 cells. Simultaneously, MBE inhibited both osteoclastogenesis in primary bone marrow macrophages and pit formation by maturated osteoclasts on dentine slices. Microcomputed tomography (micro-CT) and bone histomorphometry analyses of femurs demonstrated that the daily ingestion of MBE significantly increased BV/TV (ratio of bone volume to tissue volume), Tb.Th (trabecular thickness), Tb.N (trabecular number), N.Nd/N.Tm (node to terminus ratio), OV/TV (ratio of osteoid volume to tissue volume), BFR/TV (bone formation rate per tissue volume), and significantly decreased Tb.Sp (trabecular separation), ES/BS (ratio of eroded surface to bone surface) and N.Oc/BS (number of osteoclast per unit of bone surface), compared to vehicle controls in osteopenic mouse models. These findings suggest that MBE can be a promising natural agent for the prevention of bone loss in osteopenic conditions by not only inhibiting bone resorption, but also stimulating bone formation.

Petunidin, a B-ring 5'-O-Methylated Derivative of Delphinidin, Stimulates Osteoblastogenesis and Reduces sRANKL-Induced Bone Loss

Several lines of evidence suggest that oxidative stress is one of the key pathogenic mechanisms of osteoporosis. We aimed to elucidate the bone protective effects of petunidin, one of the most common anthocyanidins, considering its potent antioxidative activity. Petunidin (>5 μg/mL) significantly inhibited osteoclastogenesis and downregulated c-fos, Nfatc1, Mmp9, Ctsk, and Dc-stamp mRNA expression in RAW264.7 cells. Conversely, petunidin (>16 μg/mL) stimulated mineralized matrix formation and gene expression of Bmp2 and Ocn, whereas it suppressed Mmp13, Mmp2, and Mmp9 mRNA expression and proteolytic activities of MMP13 and MMP9 in MC3T3-E1 cells. Micro-CT and bone histomorphometry analyses of sRANKL-induced osteopenic C57BL/6J mice showed that daily oral administration of petunidin (7.5 mg/kg/day) increased bone volume to tissue volume (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), the ratio of osteoid volume to tissue volume (OV/TV), osteoid thickness (O.Th), the ratio of osteoid surface to bone surface (OS/BS), the ratio of osteoblast surface to bone surface (Ob.S/BS), and the number of osteoblast per unit of bone surface (N.Ob/BS), and decreased trabecular separation (Tb.Sp), the ratio of eroded surface to bone surface (ES/BS), the ratio of osteoclast surface to bone surface (Oc.S/BS), and number of osteoclast per unit of bone surface (N.Oc/BS), compared to untreated mice. Furthermore, histological sections of the femurs showed that oral administration of petunidin to sRANKL-induced osteopenic mice increased the size of osteoblasts located along the bone surface and the volume of osteoid was consistent with the in vitro osteoblast differentiation and MMP inhibition. These results suggest that petunidin is a promising natural agent to improve sRANKL-induced osteopenia in mice through increased osteoid formation, reflecting accelerated osteoblastogenesis, concomitant with suppressed bone resorption.

Piceatannol attenuates RANKL-induced osteoclast differentiation and bone resorption by suppressing MAPK, NF-κB and AKT signalling pathways and promotes Caspase3-mediated apoptosis of mature osteoclasts

Osteoclasts are multinuclear giant cells that have unique ability to degrade bone. The search for new medicines that modulate the formation and function of osteoclasts is a potential approach for treating osteoclast-related bone diseases. Piceatannol (PIC) is a natural organic polyphenolic stilbene compound found in diverse plants with a strong antioxidant and anti-inflammatory effect. However, the effect of PIC on bone health has not been scrutinized systematically. In this study, we used RAW264.7, an osteoclast lineage of cells of murine macrophages, to investigate the effects and the underlying mechanisms of PIC on osteoclasts. Here, we demonstrated that PIC treatment ranging from 0 to 40 µM strongly inhibited osteoclast formation and bone resorption in a dose-dependent manner. Furthermore, the inhibitory effect of PIC was accompanied by the decrease of osteoclast-specific genes. At the molecular level, PIC suppressed the phosphorylation of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK1/2), NF-κB p65, IκBα and AKT. Besides, PIC promoted the apoptosis of mature osteoclasts by inducing caspase-3 expression. In conclusion, our results suggested that PIC inhibited RANKL-induced osteoclastogenesis and bone resorption by suppressing MAPK, NF-κB and AKT signalling pathways and promoted caspase3-mediated apoptosis of mature osteoclasts, which might contribute to the treatment of bone diseases characterized by excessive bone resorption.

Blueberry juice protects osteocytes and bone precursor cells against oxidative stress partly through SIRT1

Oxidative stress and abnormal osteocyte apoptosis are often related to dysregulation of bone turnover and chronic bone loss, and so fruit and vegetables with high antioxidant potential may play an important role in the prevention and/or management of osteoporosis. Osteocytes are the main regulators of bone remodelling. For the first time, we demonstrate here that blueberry juice (BJ), obtained from Vaccinium myrtillus, rich in polyphenols, shows antioxidant and antiosteoclastogenic properties in MLO‐Y4 osteocytes. We report that BJ prevents oxidative stress‐induced apoptosis and reverses the increase in receptor activator of nuclear factor κB ligand and sclerostin expression, crucial factors for osteoclast activation and bone resorption. BJ is also able to prevent oxidative stress‐induced cell cytotoxicity in bone marrow mesenchymal stromal cells (MSCs), which are considered to be an important tool for cell therapy in bone disorders. No significant difference in preventing these events was observed between BJ and blueberry dry extract containing equal amounts of total soluble polyphenols. We have also shown that blueberry acts as both an antioxidant and an activator of sirtuin type 1, a class III histone deacetylase involved in cell death regulation and considered a molecular target for blocking bone resorption without affecting osteoclast survival. Overall, these novel data obtained in osteocytes and MSCs may help us clarify the mechanisms by which blueberry counteracts oxidative stress‐induced damage in bone remodelling and osteogenesis at the cellular and molecular level. Our findings are consistent with the reported beneficial effects of blueberry on bone tissue reported in animal studies, which suggest that blueberry may be a useful supplement for the prevention and/or management of osteoporosis and osteogenic process.

Modulatory Effects of Plant Polyphenols on Bone Remodeling: A Prospective View From the Bench to Bedside

During the past, a more comprehensive knowledge of mechanisms implicated in bone resorption processes has driven researchers to develop a compound library of many small molecules that specifically interfere with the genesis of osteoclast precursors cells. Natural compounds that suppress osteoclast commitment may have therapeutic value in treating pathologies associated with bone resorption like osteoporosis, rheumatoid arthritis, bone metastasis, and periodontal disease. The present review is focused on the current knowledge on the polyphenols derived from plants that could be efficacious in suppressing osteoclast differentiation and bone resorption.

The multiple protective roles and molecular mechanisms of melatonin and its precursor N-acetylserotonin in targeting brain injury and liver damage and in maintaining bone health

Melatonin is a neurohormone associated with sleep and wakefulness and is mainly produced by the pineal gland. Numerous physiological functions of melatonin have been demonstrated including anti-inflammation, suppressing neoplastic growth, circadian and endocrine rhythm regulation, and its potent antioxidant activity as well as its role in regeneration of various tissues including the nervous system, liver, bone, kidney, bladder, skin, and muscle, among others. In this review, we summarize the recent advances related to the multiple protective roles of melatonin receptor agonists, melatonin and N-acetylserotonin (NAS), in brain injury, liver damage, and bone health. Brain injury, including traumatic brain injury, ischemic stroke, intracerebral hemorrhage, subarachnoid hemorrhage, and newborn perinatal hypoxia-ischemia encephalopathy, is a major cause of mortality and disability. Liver disease causes serious public health problems and various factors including alcohol, chemical pollutants, and drugs induce hepatic damage. Osteoporosis is the most common bone disease in humans. Due in part to an aging population, both the cost of care of fracture patients and the annual fracture rate have increased steadily. Despite the discrepancy in the pathophysiological processes of these disorders, time frames and severity, they may share several common molecular mechanisms. Oxidative stress is considered to be a critical factor in these pathogeneses. We update the current state of knowledge related to the molecular processes, mainly including anti-oxidative stress, anti-apoptosis, autophagy dysfunction, and anti-inflammation as well as other properties of melatonin and NAS. Particularly, the abilities of melatonin and NAS to directly scavenge oxygen-centered radicals and toxic reactive oxygen species, and indirectly act through antioxidant enzymes are disscussed. In this review, we summarize the similarities and differences in the protection provided by melatonin and/or NAS in brain, liver and bone damage. We analyze the involvement of melatonin receptor 1A (MT1), melatonin receptor 1B (MT2), and melatonin receptor 1C (MT3) in the protection of melatonin and/or NAS. Additionally, we evaluate their potential clinical applications. The multiple mechanisms of action and multiple organ-targeted properties of melatonin and NAS may contribute to development of promising therapies for clinical trials.

Ferulic acid may target MyD88-mediated pro-inflammatory signaling - Implications for the health protection afforded by whole grains, anthocyanins, and coffee

Higher dietary intakes of anthocyanins have been linked epidemiologically to decreased risk for metabolic syndrome, type 2 diabetes and cardiovascular events; clinical trials and rodent studies evaluating ingestion of anthocyanin-rich extracts confirm favorable effects of these agents on endothelial function and metabolic syndrome. However, these benefits of anthocyanins are lost in rats whose gut microbiome has been eliminated with antibiotic treatment - pointing to bacterial metabolites of anthocyanins as the likely protective agents. A human pharmacokinetic assessment of orally administered cyanidin-3-O-glucoside, a prominent anthocyanin, has revealed that, whereas this compound is minimally absorbed, ferulic acid (FA) is one of its primary metabolites that appears in plasma. FA is a strong antioxidant and phase 2 inducer that has exerted marked anti-inflammatory effects in a number of rodent and cell culture studies; in particular, FA is highly protective in rodent models of diet-induced weight gain and metabolic syndrome. FA, a precursor for lignan synthesis, is widely distributed in plant-based whole foods, mostly in conjugated form; whole grains are a notable source. Coffee ingestion boosts plasma FA owing to gastrointestinal metabolism of chlorogenic acid. Hence, it is reasonable to suspect that FA mediates some of the broad health benefits that have been associated epidemiologically with frequent consumption of whole grains, anthocyanins, coffee, and unrefined plant-based foods. The molecular basis of the anti-inflammatory effects of FA may have been clarified by a recent study demonstrating that FA can target the adaptor protein MyD88; this plays an essential role in pro-inflammatory signaling by most toll-like receptors and interleukin-1β. If feasible oral intakes of FA can indeed down-regulate MyD88-dependent signaling, favorable effects of FA on neurodegeneration, hypothalamic inflammation, weight gain, adipocyte and beta cell function, adiponectin secretion, vascular health, and cartilage and bone integrity can be predicted. Since FA is well tolerated, safe, and natural, it may have great potential as a protective nutraceutical, and clinical trials evaluating its effects are needed.

Protective effect of grape or apple juices in bone tissue of rats exposed to cadmium: role of RUNX-2 and RANK/L expression

The aim of this study was to investigate if grape or apple juices are able to protect bone tissue of rats exposed to cadmium. For this purpose, histopathological analysis and immunohistochemistry for RUNX-2 and RANK-L were investigated in this setting. A total of 20 adult Wistar rats were distributed into four groups (n = 5), as follows: control group, cadmium group, cadmium and grape juice group, and Cadmium and apple juice group. Control group received a single intraperitoneal (i.p.) water injection. Cadmium group received a single i.p. injection of cadmium chloride (1.2 mg/kg body weight) diluted in water. Cadmium and grape juice and cadmium and apple juice groups received a single i.p. injection of cadmium chloride (1.2 mg/kg body), and after 15 days, the rats were treated with grape or apple juices for 15 days, by gavage. All animals were euthanized 30 days after the beginning of experiment. Histopathological analysis in rat femur revealed extensive bone loss in rats intoxicated with cadmium. Grape or apple juices were able to increase bone formation. Cadmium inhibited RUNX-2 immunoexpression whereas cadmium increased RANK-L immunoexpression in rat bone cells. Grape or apple juices increased RUNX-2 and decreased RANK-L immunoexpression after cadmium intoxication. Taken together, our results demonstrate that grape or apple juices are able to exert therapeutic activity following cadmium intoxication in rat bone tissue as result of stimulatory effect of bone formation by RUNX-2 upregulation and RANK-L downregulation.

Effect of anthocyanin-rich bilberry extract on bone metabolism in ovariectomized rats

Menopause is associated with increased oxidative stress, which serves a role, in part, in the pathogenesis of postmenopausal bone loss. Fruits and vegetables are rich in antioxidative nutrients and phytochemicals. Berries are a natural source of anthocyanins, and their intake may improve bone health. The aim of the present study was to determine the effect of an anthocyanin-rich bilberry extract (VME) on bone metabolism in an ovariectomized (Ovx) rat. Female Sprague-Dawley rats (12 weeks old) were randomly divided into the following four groups: Baseline, Sham, Ovx and Ovx+VME (n=8-12 rats per group). Rats in the Baseline group were sacrificed immediately, while those in the other groups were subjected to either sham operation (Sham) or bilateral Ovx (Ovx and Ovx+VME). Rats in the Ovx+VME group were administered VME daily at a dose of 500 mg/kg body weight. At 8 weeks after surgery, bone mass and bone histomorphometry were evaluated. The femur bone mineral density (BMD) in the Ovx group was significantly lower than that in the Sham group (P<0.01). Supplementation of VME in the Ovx rats did not result in an increase in BMD. Histomorphometric analyses revealed that Ovx resulted in decreased measures of bone volume and trabecular number and increased measures of osteoid volume, mineralizing surface and bone formation rates (all P<0.01), whereas VME had no significant effects on these parameters. The present findings indicate that VME did not alter bone metabolism in Ovx rats, suggesting that consumption of VME may not be helpful in preventing postmenopausal bone loss.

Polyphenolic Nutrients in Cancer Chemoprevention and Metastasis: Role of the Epithelial-to-Mesenchymal (EMT) Pathway

The epithelial-to-mesenchymal transition (EMT) has received significant interest as a novel target in cancer prevention, metastasis, and resistance. The conversion of cells from an epithelial, adhesive state to a mesenchymal, motile state is one of the key events in the development of cancer metastasis. Polyphenols have been reported to be efficacious in the prevention of cancer and reversing cancer progression. Recently, the antimetastatic efficacy of polyphenols has been reported, thereby expanding the potential use of these compounds beyond chemoprevention. Polyphenols may affect EMT pathways, which are involved in cancer metastasis; for example, polyphenols increase the levels of epithelial markers, but downregulate the mesenchymal markers. Polyphenols also alter the level of expression and functionality of important proteins in other signaling pathways that control cellular mesenchymal characteristics. However, the specific proteins that are directly affected by polyphenols in these signaling pathways remain to be elucidated. The aim of this review is to analyze current evidence regarding the role of polyphenols in attenuating EMT-mediated cancer progression and metastasis. We also discuss the role of the most important polyphenol subclasses and members of the polyphenols in reversing metastasis and targeting EMT. Finally, limitations and future directions to improve our understanding in this field are discussed.

Dietary phlorizin enhances osteoblastogenic bone formation through enhancing β-catenin activity via GSK-3β inhibition in a model of senile osteoporosis

Osteoporosis is one of the most prevalent forms of age-related bone diseases. Increased bone loss with advancing age has become a grave public health concern. This study examined whether phlorizin and phloretin, dihydrochalcones in apple peels, inhibited senile osteoporosis through enhancing osteoblastogenic bone formation in cell-based and aged mouse models. Submicromolar phloretin and phlorizin markedly stimulated osteoblast differentiation of MC3T3-E1 cells with increased transcription of Runx2 and osteocalcin. Senescence-accelerated resistant mouse strain prone-6 (SAMP6) mice were orally supplemented with 10 mg/kg phlorizin and phloretin daily for 12 weeks. Male senescence-accelerated resistant mouse strain R1 mice were employed as a nonosteoporotic age-matched control. Oral administration of ploretin and phorizin boosted bone mineralization in all the bones of femur, tibia and vertebra of SAMP6. In particular, phlorizin reduced serum RANKL/OPG ratio and diminished TRAP-positive osteoclasts in trabecular bones of SAMP6. Additionally, treating phlorizin to SAMP6 inhibited the osteoporotic resorption in distal femoral bones through up-regulating expression of BMP-2 and collagen-1 and decreasing production of matrix-degrading cathepsin K and MMP-9. Finally, phlorizin and phloretin antagonized GSK-3β induction and β-catenin phosphorylation in osteoblasts and aged mouse bones. Therefore, phlorizin and phloretin were potential therapeutic agents encumbering senile osteoporosis through promoting bone-forming osteoblastogenesis via modulation of GSK-3β/β-catenin-dependent signaling.

Therapeutic Applications of Rose Hips from Different Rosa Species

Rosa species, rose hips, are widespread wild plants that have been traditionally used as medicinal compounds for the treatment of a wide variety of diseases. The therapeutic potential of these plants is based on its antioxidant effects caused by or associated with its phytochemical composition, which includes ascorbic acid, phenolic compounds and healthy fatty acids among others. Over the last few years, medicinal interest in rose hips has increased as a consequence of recent research that has studied its potential application as a treatment for several diseases including skin disorders, hepatotoxicity, renal disturbances, diarrhoea, inflammatory disorders, arthritis, diabetes, hyperlipidaemia, obesity and cancer. In this review, the role of different species of Rosa in the prevention of treatment of various disorders related to oxidative stress, is examined, focusing on new therapeutic approaches from a molecular point of view.

Protective Effect of Chokeberry (Aronia melanocarpa L.) Extract against Cadmium Impact on the Biomechanical Properties of the Femur: A Study in a Rat Model of Low and Moderate Lifetime Women Exposure to This Heavy Metal

The hypothesis that the consumption of Aronia melanocarpa berries (chokeberries) extract, recently reported by us to improve bone metabolism in female rats at low-level and moderate chronic exposure to cadmium (1 and 5 mg Cd/kg diet for up to 24 months), may increase the bone resistance to fracture was investigated. Biomechanical properties of the neck (bending test with vertical head loading) and diaphysis (three-point bending test) of the femur of rats administered 0.1% aqueous chokeberry extract (65.74% of polyphenols) or/and Cd in the diet (1 and 5 mg Cd/kg) for 3, 10, 17, and 24 months were evaluated. Moreover, procollagen I was assayed in the bone tissue. The low-level and moderate exposure to Cd decreased the procollagen I concentration in the bone tissue and weakened the biomechanical properties of the femoral neck and diaphysis. Chokeberry extract administration under the exposure to Cd improved the bone collagen biosynthesis and femur biomechanical properties. The results allow for the conclusion that the consumption of chokeberry products under exposure to Cd may improve the bone biomechanical properties and protect from fracture. This study provides support for Aronia melanocarpa berries being a promising natural agent for skeletal protection under low-level and moderate chronic exposure to Cd.