Blackcurrant Supplementation Improves Trabecular Bone Mass in Young but Not Aged Mice

Blackcurrant extract promotes differentiation of MC3T3‑E1 pre‑osteoblasts

Osteoporosis risk increases in menopausal individuals owing to the decrease in estrogen secretion. Blackcurrant extract (BCE) ameliorates osteoporosis; however, the underlying mechanisms are unclear. Furthermore, although BCE has phytoestrogenic activity, its effects on osteoblasts are unknown. In the present study, we investigated BCE-mediated attenuation of osteoporosis using mouse MC3T3-E1 pre-osteoblasts, with a focus on osteogenesis. After treating MC3T3-E1 cells with BCE for 48 h, cell proliferation was assessed using Cell Counting Kit-8. Levels of osteoblast differentiation markers, namely alkaline phosphatase activity and total collagen content in the cells, were evaluated after 3 and 14 days of BCE treatment, respectively. The expression of genes encoding osteoblast differentiation markers, including collagen type I (Col-I), alkaline phosphatase (Alp), bone γ-carboxyglutamate protein (Bglap), and runt-related transcription factor 2 (Runx2), was evaluated using reverse transcription-quantitative polymerase chain reaction. Mineralization of the cells was evaluated using Alizarin Red staining. Femoral tissues of ovariectomized (OVX) rats with or without 3% BCE were stained using ALP to evaluate osteogenic differentiation in femoral tissue. After treating MC3T3-E1 cells with BCE, cell proliferation had increased. BCE treatment increased Alp activity and total collagen content. Moreover, the expression of Col-I, Alp, Bglap, and Runx2 increased in BCE-treated cells. Furthermore, when MC3T3-E1 cells were treated with BCE for 21 days, the levels of calcified nodules increased. Alp staining intensity was stronger in the epiphyses on femoral tissue of OVX rats treated with 3% BCE than in those of untreated OVX rats. The results suggest that BCE may promote osteogenesis by inducing osteoblast differentiation.

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.

Blackcurrant Anthocyanins Improve Blood Lipids and Biomarkers of Inflammation and Oxidative Stress in Healthy Women in Menopause Transition without Changing Body Composition

Recent cell and animal studies suggest the potential of blackcurrants (BCs; Ribes nigrum) as a dietary agent that may reduce the risk of cardiovascular disease (CVD) by improving dyslipidemia, oxidative stress, and inflammation. This study aimed to examine the effects of BC anthocyanin (ACN) extract supplementation on biomarkers of CVD risk in healthy adult women in menopause transition. The effects of BC ACN supplementation on body composition, fasting blood lipids and biomarkers of inflammation and oxidative stress were evaluated using anthropometric measures and blood samples collected from a pilot randomized controlled clinical trial in peri- and early postmenopausal women. Thirty-eight eligible peri- and early postmenopausal women aged 45-60 completed the entire trial, in which they were randomly assigned into one of three treatment groups: placebo (control group), 392 mg/day (low BC group), or 784 mg/day (high BC group) for six months. The significance of differences in outcomes was tested using repeated-measures ANOVA. Overall, following six-month BC consumption, significantly decreased triglyceride (TG) levels were observed between treatment groups (p < 0.05) in a dose-dependent manner. Plasma interleukin-1β (IL-1β) was significantly reduced in a dose and time dependent manner (p < 0.05). Significant decreases in thiobarbituric acid reactive substances (TBARS) levels were also observed between treatment groups (p < 0.05) in a dose-dependent manner. Six-month change in oxidized LDL was inversely correlated with changes in catalase (CAT) and total antioxidant capacity (TAC) (p < 0.05), while C-reactive protein (hs-CRP) change was positively correlated with changes in TG and IL-1β (p < 0.01). Together, these findings suggest that daily BC consumption for six months effectively improved dyslipidemia, inflammation, and lipid peroxidation, thus potentially mitigating the risk of postmenopausal CVD development in study participants. Future studies with larger sample sizes and at-risk populations are warranted to confirm these findings.

Associations of Dietary Anthocyanidins Intake with Bone Health in Children: A Cross-Sectional Study

PURPOSE

Bone health and body composition share several common mechanisms like oxidative stress and inflammation. Anthocyanins have antioxidant and anti-inflammatory properties. We have reported that anthocyanins are associated with better body composition in children, but the associations with bone health have not been elucidated. We aimed to explore the association of anthocyanins with bone mineral content (BMC) and bone mineral density (BMD) at multiple sites in children.

METHODS

In this cross-sectional study, 452 Chinese children aged 6-9 years were recruited. A validated 79-item food frequency questionnaire was used to collect dietary information. BMC and BMD at multiple sites (whole body; whole body excluding head, WBEH; limbs; arms; legs) were measured by dual-energy X-ray.

RESULTS

Higher dietary intake of total anthocyanidins (per one standard deviation increase) was associated with a 1.28-13.6 g (1.31-1.60%, compared to median) higher BMC at all sites and a 3.61-6.96 mg (0.65-0.90%) higher BMD at the whole body, WBEH, and arm sites after controlling for a number of possible covariates. The results were similar and more pronounced for cyanidin, but not for delphinidin and peonidin. Higher dietary intake of cyanidin (per one standard deviation increase) was associated with a 1.33-15.4 g (1.48-1.68%) higher BMC at all sites and a 4.15-7.77 mg (0.66-1.00%) higher BMD at all sites except the legs. No statistically significant associations with BMC or BMD were found for dietary intake of delphinidin and peonidin.

CONCLUSIONS

Higher dietary intake of total anthocyanidins and cyanidins were associated with higher BMC and BMD in Chinese children.

Effect of Blackcurrant Consumption on the Genitourinary System: A Literature Review

Both in vivo and in vitro studies have shown that functional plant-based food such as fruits, vegetables, and berries can enhance health, have preventive effects, and reduce the risk of several chronic diseases. This review discusses blackcurrant fruit usage in humans and experimental animals and its effect on the genitourinary system (GUS). This comprehensive review demonstrates that blackcurrants and their bioactive compounds possess medicinal and therapeutic properties related to the GUS. Emphasis in the literature has been placed on the bioavailability of the active blackcurrant components. Nonetheless, future clinical trials are needed to investigate and improve the bioavailability of blackcurrant phenolic compounds, such as anthocyanins, and to expand the evidence that active blackcurrant compounds can treat various genitourinary diseases.

Blackcurrants Reduce the Risk of Postmenopausal Osteoporosis: A Pilot Double-Blind, Randomized, Placebo-Controlled Clinical Trial

Beneficial effects of blackcurrant supplementation on bone metabolism in mice has recently been demonstrated, but no studies are available in humans. The current study aimed to examine the dose-dependent effects of blackcurrant in preventing bone loss and the underlying mechanisms of action in adult women. Forty peri- and early postmenopausal women were randomly assigned into one of three treatment groups for 6 months: (1) a placebo (control group, n = 13); (2) 392 mg/day of blackcurrant powder (low blackcurrant, BC, group, n = 16); and (3) 784 mg/day of blackcurrant powder (high BC group, n = 11). The significance of differences in outcome variables was tested by repeated-measures ANOVA with treatment and time as between- and within-subject factors, respectively. Overall, blackcurrant supplementation decreased the loss of whole-body bone mineral density (BMD) compared to the control group (p < 0.05), though the improvement of whole-body BMD remained significant only in the high BC group (p < 0.05). Blackcurrant supplementation also led to a significant increase in serum amino-terminal propeptide of type 1 procollagen (P1NP), a marker of bone formation (p < 0.05). These findings suggest that daily consumption of 784 mg of blackcurrant powder for six months mitigates the risk of postmenopausal bone loss, potentially through enhancing bone formation. Further studies of larger samples with various skeletal conditions are warranted to confirm these findings.

Functional role of cyanidin-3-O-glucoside in osteogenesis: A pilot study based on RNA-seq analysis

Cyanidin-3-O-glucoside (C3G) is the most widely distributed anthocyanin and it can reportedly reduce the risk of osteoporosis, but the molecular mechanism by which C3G promotes bone formation is poorly understood. In the current study, RNA sequencing (RNA-seq) was used to investigate the mechanism of action of C3G in osteogenesis. MC3T3-E1 mouse osteoblasts were divided into a C3G (100 μmol/L)-treated group and a vehicle-treated control group, and differentially expressed genes (DEGs) in groups were evaluated via RNA-seq analysis. The functions of the DEGs were evaluated by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, and the genes were validated by quantitative real-time PCR. The RNA-seq analysis identified 34 genes that were upregulated in C3G-treated cells compared to vehicle-treated cells, and 17 that were downregulated GO and KEGG pathway analyses indicated that these genes were highly enriched in functions related to lysosomes and glycolipid biosynthesis, among others. The differential expression of ATPase H+-transporting V0 subunit C (Atp6v0c), chemokine (C-X3-C motif) ligand 1 (Cx3cl1), and lymphocyte antigen 6 complex, locus A (Ly6a) genes was validated by quantitative real-time-PCR. Because these genes have been previously implicated in osteoporosis, they are potential target genes of C3G action in MC3T3-E1 cells. These results provide molecular level evidence for the therapeutic potential of C3G in the treatment of osteoporosis and other disorders of bone metabolism.

Anti-Osteoclast Effect of Exportin-1 Inhibitor Eltanexor on Osteoporosis Depends on Nuclear Accumulation of IκBα–NF-κB p65 Complex

Osteoporosis affects around 200 million people globally, with menopausal women accounting for the bulk of cases. In the occurrence and development of osteoporosis, a key role is played by osteoclasts. Excessive osteoclast-mediated bone resorption activity reduces bone mass and increases bone fragility, resulting in osteoporosis. Thus, considerable demand exists for designing effective osteoporosis treatments based on targeting osteoclasts. Eltanexor (Elt; KPT-8602) is a selective nuclear-export inhibitor that covalently binds to and blocks the function of the nuclear-export protein exportin-1 (XPO1), which controls the nucleus-to-cytoplasm transfer of certain critical proteins related to growth regulation and tumor suppression, such as p53, IκBα [nuclear factor-κB (NF-κB) inhibitor α] and FOXO1; among these proteins, IκBα, a critical component of the NF-κB signaling pathway that primarily governs NF-κB activation and transcription. How Elt treatment affects osteoclasts remains poorly elucidated. Elt inhibited the growth and activity of RANKL-induced osteoclasts in vitro in a dose-dependent manner, and Elt exerted no cell-killing effect within the effective inhibitory concentration. Mechanistically, Elt was found to trap IκBα in the nucleus and thus protect IκBα from proteasome degradation, which resulted in the blocking of the translocation of IκBα and NF-κB p65 and the consequent inhibition of NF-κB activity. The suppression of NF-κB activity, in turn, inhibited the activity of two transcription factors (NFATc1 and c-Fos) essential for osteoclast formation and led to the downregulation of genes and proteins related to bone resorption. Our study thus provides a newly identified mechanism for targeting in the treatment of osteoporosis.

Research Progress of the Role of Anthocyanins on Bone Regeneration

Bone regeneration in osteoporosis and fragility fractures which are highly associated with age remains a great challenge in the orthopedic field, even though the bone is subjected to a continuous process of remodeling which persists throughout lifelong. Regulation of osteoblast and osteoclast differentiation is recognized as effective therapeutic targets to accelerate bone regeneration in osteopenic conditions. Anthocyanins (ACNs), a class of naturally occurring compounds obtained from colored plants, have received increasing attention recently because of their well-documented biological effects, such as antioxidant, anti-inflammation, and anti-apoptosis in chronic diseases, like osteoporosis. Here, we summarized the detailed research progress on ACNs on bone regeneration and their molecular mechanisms on promoting osteoblast differentiation as well as inhibiting osteoclast formation and differentiation to explore their promising therapeutic application in repressing bone loss and helping fragility fracture healing. Better understanding the role and mechanisms of ACNs on bone regeneration is helpful for the prevention or treatment of osteoporosis and also for the exploration of new bone regenerative medicine.

Peonidin-3-O-glucoside and cyanidin increase osteoblast differentiation and reduce RANKL-induced bone resorption in transgenic medaka

Experimental and clinical studies suggest a positive impact of anthocyanins on bone health; however, the mechanisms of anthocyanins altering the differentiation and function of osteoblasts and osteoclasts are not fully understood. This work demonstrates that dietary anthocyanins and resveratrol increased proliferation of cultured human hFOB 1.19 osteoblasts. In addition, treatment of serum starvation of hFOB osteoblasts with anthocyanins and resveratrol at 1.0 μg/ml reduced apoptosis, the Bax/Bcl-2 ratio, p53, and HDAC1 expression, but increased SIRT1/3 and PGC1α mRNA expression, suggesting mitochondrial and epigenetic regulation. In Sp7/osterix:mCherry transgenic medaka, peonidin-3-O-glucoside and resveratrol increased osteoblast differentiation and increased the expression of Sp7/osterix. Cyanidin, peonidin-3-O-glucoside, and resveratrol also reduced RANKL-induced ectopic osteoclast formation and bone resorption in col10α1:nlGFP/rankl:HSE:CFP medaka in doses of 1-4 μg/ml. The results indicate that both cyanidin and peonidin-3-O-glucoside have anabolic effects on bone, increasing osteoblast proliferation and differentiation, mitochondrial biogenesis, and by altering the osteoblast epigenome. Cyanidin and peonidin-3-O-glucoside also reduced RANKL-induced bone resorption in a transgenic medaka model of bone resorption. Thus, peonidin-3-O-glucoside and cyanidin appear to both increase bone formation and reduce bone loss, suggesting that they be further investigated as potential treatments for osteoporosis and osteomalacia.

Analysis of the molecular mechanisms by flavonoids with potential use for osteoporosis prevention or therapy

BACKGROUND

Osteoporosis is the most common skeletal disorder worldwide. Flavonoids have the potential to alleviate bone alterations in osteoporotic patients with the advantage of being safer and less expensive than the conventional therapies.

OBJECTIVE

The main objective is to analyze the molecular mechanisms triggered in bone by different subclasses of flavonoids. In addition, this review provides an up-to-date overview on the cellular and molecular aspects of osteoporotic bones versus healthy bones, and a brief description of some epidemiological studies indicating that flavonoids could be useful for osteoporosis treatment.

METHODS

The PubMed database was searched in the range of years 2001- 2021 using the keywords osteoporosis, flavonoids, and their subclasses such as flavones, flavonols, flavanols, isoflavones, flavanones and anthocyanins, focusing the data on the molecular mechanisms triggered in bone.

RESULTS

Although flavonoids comprise many compounds that differ in structure, their effects on bone loss in postmenopausal women or in ovariectomized-induced osteoporotic animals are quite similar. Most of them increase bone mineral density and bone strength, which occur through enhancement of osteoblastogenesis and osteoclast apoptosis, decrease in osteoclastogenesis as well as increase in neovascularization on the site of the osteoporotic fracture.

CONCLUSION

Several molecules of signaling pathways are involved in the effect of flavonoids on osteoporotic bone. Whether all flavonoids have a common mechanism or they act as ligands of estrogen receptors remain to be established. More clinical trials are necessary to know better their safety, efficacy, delivery and bioavailability in humans, as well as comparative studies with conventional therapies.

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.

Cyanidin-3-glucoside Regulates Osteoblast Differentiation via the ERK1/2 Signaling Pathway

Osteoporosis, characterized by a gradual decrease in the number of osteoblasts and a gradual increase in bone resorption of osteoclasts in bone tissue, is a global chronic disease, which severely impairs the quality of life of the elderly. Therefore, it is extremely urgent to study the prevention and treatment of osteoporosis. It has been reported that anthocyanins can regulate bone metabolism and prevent osteoporosis. Cyanidin-3-O-glucoside (C3G), the most common type of anthocyanin in nature, widely exists in a variety of vegetables and fruits. Although it has been shown that C3G has multiple effects on osteoclasts, its impact(s) and underlying mechanism(s) on osteoblasts are still not clear. Here, we evaluated the effect of C3G on cell proliferation and differentiation of osteoblasts (extracted from the hip joint of patients with osteoporosis) and MC3T3-E1 (a kind of osteoblast cell line from mice). We also test the ability of osteoblasts to mineralize after C3G treatment. To find the underlying mechanism of the above effects, we further evaluated the role of the ERK signaling pathway in C3G regulation of osteoblasts. The results showed that C3G treatment enhanced osteoblast proliferation rate, osteoblast mineralization points, the mRNA levels and protein expression levels of OC (osteocalcin), and the level of ERK phosphorylation, which could be blocked by pretreatment with ERK signaling pathway inhibitor. The above results not only indicate that the ERK pathway was involved in C3G regulation of osteoblast differentiation but also provide strong suggestive evidence that osteoblasts may be promising targets in preventive and therapeutic strategies for osteoporosis.

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.

Orange juice intake and anthropometric changes in children and adolescents

OBJECTIVE

Evaluate associations between orange juice (OJ) consumption and anthropometric parameters.

DESIGN

Prospective cohort study assessing the association between OJ intake and changes in BMI and height-for-age Z-score (HAZ) using mixed linear regression.

SETTING

2004-2008, USA.

PARTICIPANTS

Children from the Growing Up Today Study II (n 7301), aged 9-16 years at enrollment.

RESULTS

OJ consumption was positively associated with 2-year change in HAZ in girls (mean (se)): 0·03 (0·01) for non-consumers, 0·03 (0·02) for 1-3 glasses/month, 0·06 (0·01) for 1-6 glasses/week and 0·09 (0·02) for ≥1 glass/d after full adjustment (Ptrend = 0·02). However, OJ consumption was not associated with 2-year change in BMI percentile (kg/m2, mean (se)): -0·44 (0·36) for non-consumers, 0·20 (0·41) for 1-3 glasses/month, -0·04 (0·34) for 1-6 glasses/week and -0·77 (0·62) for ≥1 glass/d in girls, Ptrend = 0·81; -0·94 (0·53) for non-consumers, -1·68 (0·52) for 1-3 glasses/month, -0·81 (0·38) for 1-6 glasses per week and -1·12 (0·61) for ≥1 glass/d in boys, Ptrend = 0·49.

CONCLUSION

OJ consumption was favourably associated with height growth but unrelated to excess weight gain. OJ may be a useful alternative to whole fruit in the event that whole fruit intake is insufficient.

Long-Term Blackcurrant Supplementation Modified Gut Microbiome Profiles in Mice in an Age-Dependent Manner: An Exploratory Study

Recent studies have suggested that blackcurrant (BC) anthocyanins have promising health benefits, possibly through regulating gut microbiome. Three- and eighteen-month old female mice were fed standard mouse diets for 4 months, each with or without BC (1% w/w) supplementation (n = 3 in each treatment group, 12 in total). We then assessed gut microbiome profiles using 16S sequencing of their feces. Old mice had a less diverse microbiome community compared to young mice and there was a remarkable age-related difference in microbiome composition in the beta diversity analysis. BC supplementation did not significantly affect alpha or beta diversity. The relative abundance of several phyla, including Firmicutes, Bacteroidetes, Proteobacteria and Tenericutes, was lower in old mice. BC downregulated Firmicutes abundance in young mice and upregulated Bacteroidetes in both age groups, leading to a decreased Firmicutes/Bacteroidetes ratio. There were age-specific differences in the effect of BC supplementation on the microbiome. Twenty-four operational taxonomic units showed a significant interaction between age and BC supplementation (p < 0.01), which suggests that the ecosystem and the host health status affect the functions and efficiency of BC intake. These results indicate that BC supplementation favorably modulates gut microbiome, but there are distinct age-specific differences. Studies with human hosts are needed to better understand BC’s regulatory effects on the gut microbiome.

Dietary Anthocyanins and Human Health

Anthocyanins may contribute to the inverse relationship between fruit and vegetable intake and chronic disease. Anthocyanins are pigments found in plant structures that consist of an anthocyanidin (aglycone) attached to sugar moieties. Anthocyanins may be beneficial for health through effects on cellular antioxidant status and inflammation; however, their underlying mechanisms of action in their protection of chronic diseases are likely complex and require further elucidation. This Special Issue comprises 8 peer-reviewed papers (including 6 original research articles) which highlight the diverse bioactivities of anthocyanins and anthocyanin-rich foods in the protection against chronic disease.