A mechanistic review of chinese medicine polyphenols on bone formation and resorption

Causal relationship between tea intake and bone mineral density at different ages ̶ A Mendelian randomization study

INTRODUCTION

bone mineral density (BMD) is strongly associated with the risk of osteoporosis and fractures. Furthermore, dietary tea consumption also has a great impact on the variation in BMD. The pathway mechanisms from tea consumption to BMD are not well known. Therefore, we applied a two-sample Mendelian randomization (MR) approach in an attempt to explore the causality between tea consumption and BMD. And then examine whether the effects of tea intake on BMD are specific across different age groups.

METHODS

we investigated the relationship between tea consumption and BMD using a two-sample Mendelian randomization analysis, utilizing 31 single nucleotide polymorphisms (SNPs) related to tea intake from pooled data from a gene-wide association study (GWAS) of 447,485 British Biobank of European Origin participants, with BMD derived from a meta-analysis of total body BMD and age-specific effects in the Lifelong Genetic Cohort Study (n = 66,628). Causal analysis between tea intake and BMD was performed using MR-Egger, inverse variance weighting (IVW), weighted median, and weighted mode.

RESULTS

in IVW, tea consumption has a positive causal effect on total body BMD. However, in different age groups, BMD has a positive effect only within the 45-60-year group. There is no genetic pleiotropy effect of tea intake can have an effect on systemic BMD or among the five different age groups. The Cochran Q statistic and MR-Egger regression were applied to calculate heterogeneity in the IVW method, and no significant heterogeneity was indicated.

CONCLUSIONS

the results of the MR analysis showed a positive causal effect of tea intake on total body BMD, whereas among the different age groups, tea intake positively affected BMD only in the 45-60 age group, which implies that tea is beneficial in maintaining or increasing BMD in this age group and may reduce osteoporosis and fracture risk.

Polyphenols and Functionalized Hydrogels for Osteoporotic Bone Regeneration

Osteoporosis induces severe oxidative stress and disrupts bone metabolism, complicating the treatment of bone defects. Current therapies often have side effects and require lengthy bone regeneration periods. Hydrogels, known for their flexible mechanical properties and degradability, are promising carriers for drugs and bioactive factors in bone tissue engineering. However, they lack the ability to regulate the local pathological environment of osteoporosis and expedite bone repair. Polyphenols, with antioxidative, anti-inflammatory, and bone metabolism-regulating properties, have emerged as a solution. Combining hydrogels and polyphenols, polyphenol-based hydrogels can regulate local bone metabolism and oxidative stress while providing mechanical support and tissue adhesion, promoting osteoporotic bone regeneration. This review first provides a brief overview of the types of polyphenols and the mechanisms of polyphenols in facilitating adhesion, antioxidant, anti-inflammatory, and bone metabolism modulation in modulating the pathological environment of osteoporosis. Next, this review examines recent advances in hydrogels for the treatment of osteoporotic bone defects, including their use in angiogenesis, oxidative stress modulation, drug delivery, and stem cell therapy. Finally, it highlights the latest research on polyphenol hydrogels in osteoporotic bone defect regeneration. Overall, this review aims to facilitate the clinical application of polyphenol hydrogels for the treatment of osteoporotic bone defects.

Exploring the therapeutic potential of isoorientin in the treatment of osteoporosis: a study using network pharmacology and experimental validation

BACKGROUND

Isoorientin (ISO) is a glycosylated flavonoid with antitumor, anti-inflammatory, and antioxidant properties. However, its effects on bone metabolism remain largely unknown.

METHODS

In this study, we aimed to investigate the effects of ISO on receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast formation in vitro and bone loss in post-ovariectomy (OVX) rats, as well as to elucidate the underlying mechanism. First, network pharmacology analysis indicated that MAPK1 and AKT1 may be potential therapeutic targets of ISO and that ISO has potential regulatory effects on the mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) pathways, as well as oxidative stress. ISO was added to RAW264.7 cells stimulated by RANKL, and its effects on osteoclast differentiation were evaluated using tartrate-resistant acid phosphatase (TRAP) staining, TRAP activity measurement, and F-actin ring analysis. Reactive oxygen species (ROS) production in osteoclasts was detected using a ROS assay kit. The effects of ISO on RANKL-triggered molecular cascade response were further investigated by Western blotting, quantitative real-time polymerase chain reaction, and immunofluorescence staining. In addition, the therapeutic effects of ISO were evaluated in vivo.

RESULTS

ISO inhibited osteoclastogenesis in a time- and concentration-dependent manner. Mechanistically, ISO downregulated the expression of the main transcription factor for osteoclast differentiation by inhibiting MAPK and PI3K/AKT1 signaling pathways. Moreover, ISO exhibited protective effects in OVX-induced bone loss rats. This was consistent with the results derived from network pharmacology.

CONCLUSION

Our findings suggest a potential therapeutic utility of ISO in the management of osteoclast-associated bone diseases, including osteoporosis.

Boosting plant food polyphenol concentration by saline eustress as supplement strategies for the prevention of metabolic syndrome: an example of randomized interventional trial in the adult population

Introduction

Phenolic compounds in lettuce can increase by the application of positive stress (eustress) such as moderate saline stress. Phenolic compounds possess antioxidant capacity that is a key factor in the detoxification of excess reactive oxygen species. A double-blinded randomized interventional and placebo- controlled study design was carried out to compare the effect of daily dietary eustress lettuce ingestion in hepatic, lipid, bone, glucose, and iron metabolism.

Methods

Forty-two healthy volunteers, 19 female and 23 male participants, were divided into two groups. Participants were randomized into a polyphenol-enriched treatment (PET) arm or control arm. Each arm consumed 100 g/day of control or eustress (polyphenols enriched treatment = PET) lettuce for 12 days. Primary study outcomes were serological analysis for assessing hepatic, lipid, bone, iron, and glucose markers at baseline and after 12 days. Secondary outcomes assessed body composition.

Results

Salinity stress reduced plant yield but increased caffeic acid (+467%), chlorogenic acid (+320%), quercetin (+538%), and rutin (+1,095%) concentrations. The intake of PET lettuce reduced PTH, low-density lipoprotein (LDL), cholesterol, alanine transaminase (ALT), and aspartate transaminase (AST) enzyme levels and increased vitamin D and phosphate levels, while iron and glucose metabolism were unaffected.

Discussion

Supplementation with eustress lettuce by increasing polyphenols concentration ameliorates hepatic, lipid, and bone homeostasis. Body composition was not affected.

Clinical trial registration

https://classic.clinicaltrials.gov/ct2/show/NCT06002672, identifier: NCT06002672.

The Development of Naringin for Use against Bone and Cartilage Disorders

Bone and cartilage disorders are the leading causes of musculoskeletal disability. There is no absolute cure for all bone and cartilage disorders. The exploration of natural compounds for the potential therapeutic use against bone and cartilage disorders is proving promising. Among these natural chemicals, naringin, a flavanone glycoside, is a potential candidate due to its multifaceted pharmacological activities in bone and cartilage tissues. Emerging studies indicate that naringin may promote osteogenic differentiation, inhibit osteoclast formation, and exhibit protective effects against osteoporosis in vivo and in vitro. Many signaling pathways, such as BMP-2, Wnt/β-catenin, and VEGF/VEGFR, participate in the biological actions of naringin in mediating the pathological development of osteoporosis. In addition, the anti-inflammatory, anti-oxidative stress, and anti-apoptosis abilities of naringin also demonstrate its beneficial effects against bone and cartilage disorders, including intervertebral disc degeneration, osteoarthritis, rheumatoid arthritis, bone and cartilage tumors, and tibial dyschondroplasia. Naringin exhibits protective effects against bone and cartilage disorders. However, more efforts are still needed due to, at least in part, the uncertainty of drug targets. Further biological and pharmacological evaluations of naringin and its applications in bone tissue engineering, particularly its therapeutic effects against osteoporosis, might result in developing potential drug candidates.