Oxidative Stress and Osteoporosis

Salvianolic acid-A alleviates oxidative stress-induced osteoporosis

AIM

Cellular damage induced by oxidative stress contributes to systemic bone disorders leading to osteoporosis. Bone homeostasis regulates the balance between the functions of osteoblasts and osteoclasts. Osteoblast cells are responsible for bone formation and are very sensitive to oxidative stress. Polyphenolic compounds possess the ability to scavenge free radicals, thus reducing intracellular oxidative stress. Natural compounds such as salvianolic acid A (SAL-A) exhibit prominent antioxidant properties. However, its antioxidant role in bone homeostasis is poorly defined. In this study, we aimed to elucidate the potential role of SAL-A in protecting the osteoblasts from H2O2-induced oxidative stress.

MAIN METHODS

Rat osteoblast cells were treated with or without 500 μM H2O2 in the presence or absence of 5 μM and 10 μM of SAL-A. A series of assays such as cell viability by CCK-8 kit, detection of reactive oxygen species by dichlorodihydrofluorescein diacetate (DCFH-DA), mitochondrial membrane potential by JC-1 fluorescence, level of bone mineralization proteins osteocalcin, bone sialoprotein, and alkaline phosphatase by immunocytochemistry studies, were conducted.

KEY FINDINGS

SAL-A protected the rat osteoblast cells from H2O2-induced cytotoxicity by significantly attenuating free radical generation, thus improving cell viability. SAL-A treatment also significantly restored bone mineralization proteins, including osteocalcin, bone sialoprotein, and alkaline phosphatase, which were aggravated by H2O2-induced oxidative stress.

SIGNIFICANCE

The study results provide the role of SAL-A in protecting the osteoblasts from H2O2-induced oxidative stress in rat osteoblast cells by scavenging the free radicals, increasing the cell viability, mineralization, and differentiation of osteoblasts.

Periprosthetic osteolysis: Mechanisms and potential treatment strategies

Periprosthetic osteolysis is a common bone-related disorder that often occurs after total hip arthroplasty. The implants can cause damage to bone and bone-related cells due to mechanical stress and micromotions, resulting in the generation of a large number of wear particles. These wear particles trigger inflammation and oxidative stress in the surrounding tissues, disrupting the delicate balance maintained by osteoblasts and osteoclasts, ultimately leading to bone loss around the implant. Clinical investigations have demonstrated that Epimedium prenylflavonoids, miR-19a-3p, stem cell-derived exosomes, and certain non-PPO category pharmaceuticals have regulatory effects on bone homeostasis through distinct molecular pathways. Notably, this phenomenon reflects inherent biological rationality rather than stochastic occurrence. Extensive research has revealed that multiple natural compounds, non-coding RNAs, exosomes, and non-PPO therapeutics not only exert modulatory influences on critical pathophysiological processes including inflammatory cascades, oxidative stress responses, and tissue regeneration mechanisms, but also effectively regulate bone-related cellular functions to inhibit PPO progression. Therefore, this review comprehensively and systematically summarizes the main pathogenic mechanisms of periprosthetic osteolysis. Furthermore, it delves deeper into the research progress on the applications of currently reported natural products, ncRNAs, exosomes, and non-PPO medications in the treatment of periprosthetic osteolysis. Based on this, we hope that this paper can provide new perspectives and references for the future development of drugs targeting periprosthetic osteolysis.

The bone-vascular axis: the link between osteoporosis and vascular calcification

Osteoporosis and vascular calcification are chronic metabolic diseases threatening the health of aging people. The incidence of osteoporosis and vascular calcification increases year by year, and has drawn much attention from the scientific and clinical area. Many studies have found that osteoporosis and vascular calcification are not completely independent, but there are close correlations between them in the pathogenesis and underlying mechanisms. The underlying mechanisms of osteoporosis and vascular calcification include aging, oxidative stress, inflammatory response, lipid metabolism, calcium and phosphorus metabolism, vitamins, autophagy, and extracellular vesicles. This review updates the current understanding of the correlation and underlying mechanisms of osteoporosis and vascular calcification, and highlights the complexity of the bone-vascular axis, aiming to provide novel ideas for the prevention and treatment of osteoporosis and vascular calcification.

Obstructive sleep apnea and osteoporosis: A bidirectional two-sample mendelian randomization analysis

BACKGROUND

Previous epidemiological studies have explored the association between obstructive sleep apnea (OSA) and osteoporosis (OP), with inconclusive results due to various biases. Herein, we sought to determine the causal association between OSA and OP through bidirectional two-sample Mendelian randomization analysis.

METHODS

Summary-level data for OSA were acquired from the FinnGen consortium, while data for fractures and BMDs (FA-BMD, FN-BMD, LS-BMD and eBMD) were derived from the UKBB and GEFOS. The inverse variance weighted (IVW) method was conducted as the main method, and several supplementary methods were further utilized for sensitivity analysis to strengthen the reliability of our findings.

RESULTS

The study findings strongly suggest a causal association between OSA and FA-BMD based on the IVW method (BETA = 0.404; 95 % CI = 0.208, 0.599; p = 5.28 × 10-5). However, OSA showed no significant causal relationship with eBMD (BETA = 0.052; 95 % CI = -0.018, 0.123; p = 0.145), FN-BMD (BETA = 0.095; 95 % CI = -0.009, 0.2; p = 0.073), LS-BMD (BETA = 0.021; 95 % CI = -0.082, 0.124; p = 0.695), and fractures (OR = 0.998; 95 % CI = 0.907, 1.098; p = 0.971). The conclusions from other analytical strategies were generally aligned with those of the IVW. No definitive causal effect of OP on OSA was observed in reverse analysis.

CONCLUSION

This research provided clear evidence of a causal association between OSA and FA-BMD, shedding light on the potential impact of OSA on bone metabolism.

Relationships among osteoporosis, redox homeostasis, and alcohol addiction: Importance of the brain-bone axis

Overabundance of reactive oxygen species (oxidative distress) leads to redox homeostasis disturbance and is associated with many pathological conditions. Accumulating evidence suggests that oxidative distress may contribute to osteoporosis. This review thoroughly outlines the relationships among osteoporosis, redox homeostasis, and alcohol addiction, since these relations are not sufficiently known and subsequently summarized. The brain-bone axis plays a crucial role in alcohol-induced damage to the nervous and skeletal systems. Alterations in the nervous system can lead to osteoporosis because the central nervous system is involved in bone remodeling through various neural pathways. Conversely, as an endocrine organ, bone secretes a number of bone-derived factors (osteokines), which can influence brain function and behavior. As a result, osteoporosis is more common in individuals with neurological disorders, and sudden neurological events can rapidly increase the risk of osteoporosis. Excessive alcohol consumption is linked to many neurological complications, as well as osteoporosis, which are manifested by disrupted redox homeostasis, inflammation, neurodegeneration, inhibition of neurogenesis, decreased bone mineral density, impaired bone microarchitecture, altered mineral homeostasis, raising fracture risk, hormonal dysregulation, and altered gut microbiota composition. Compared to men, alcohol dependence has more negative consequences for women, including an increased risk of liver, cardiovascular, metabolic, mental disorders, and breast cancer. Abstinence has been demonstrated to improve bone and brain health in alcohol addiction. The discovery of the brain-bone axis may lead to the development of new therapeutic approaches for alcohol and other substance addictions. Further research is needed in this direction, as many questions remain unanswered.

Association of dietary patterns with osteoporosis risk: a meta-analysis of observational studies

BACKGROUND

Dietary patterns play a crucial role in osteoporosis prevention and management. Patients with osteoporosis need to select a dietary pattern for prevention. This meta-analysis aims to examine the influence of eight distinct dietary patterns on the risk of osteoporosis, including dietary inflammatory index (DII), Western/unhealthful dietary pattern, dietary approaches to stop hypertension (DASH), prudent/healthful dietary pattern, aquatic dietary pattern, plant-based diet index (PDI), healthful PDI, and unhealthful PDI.

METHODS

Embase, Web of Science, PubMed, and Cochrane Library were systematically searched for observational studies up to April 10, 2025. Meta-analysis was conducted using random-effect models. Heterogeneity was evaluated by subgroup analyses and publication bias was assessed by Egger's test. If there was a risk of bias, the sensitivity analysis and trim-and-fill analysis were conducted. The odds ratios (ORs) and 95% confidence intervals (CIs) were combined to compare the lowest and highest dietary pattern categories.

RESULTS

A total of 2,620 studies were retrieved, among which 2,600 were excluded. 20 observational studies, involving 8 dietary patterns were included, with 426,292 participants. The highest DII (OR: 1.82; 95% CI: 1.39, 2.37; P < 0.001) and the high adherence of unhealthful PDI (OR: 1.37; 95% CI: 1.11, 1.68; P = 0.003) were correlated with an increased risk of osteoporosis. Conversely, the highest category of the prudent/healthful dietary pattern (OR: 0.66; 95% CI: 0.53, 0.83; P < 0.001) presented a low osteoporosis risk. The Western/unhealthful dietary pattern, DASH, aquatic dietary pattern, and high adherence to PDI and healthy PDI dietary patterns were not associated with osteoporosis risk (All P > 0.05).

CONCLUSION

High DII or unhealthy PDI scores were associated with an increased risk of osteoporosis, while high adherence to prudent/healthy dietary patterns reduced the risk of osteoporosis.

TRIAL REGISTRATION

This paper was registered with PROSPERO (CRD42024585588).

New Perspectives on Postmenopausal Osteoporosis: Mechanisms and Potential Therapeutic Strategies of Sirtuins and Oxidative Stress

Estrogen levels are the core factor influencing postmenopausal osteoporosis (PMOP). Estrogen can affect the progression of PMOP by regulating bone metabolism, influencing major signaling pathways related to bone metabolism, and modulating immune responses. When estrogen levels decline, the activity of Sirtuins (SIRTs) is reduced. SIRTs are enzymes that function as NAD+-dependent deacetylases. SIRTs can modulate osteocyte function, sustain mitochondrial homeostasis, and modulate relevant signaling pathways, thereby improving bone metabolic imbalances, reducing bone resorption, and promoting bone formation. In PMOP, SIRT1, SIRT3, and SIRT6 are primarily affected. Oxidative stress (OS) is a crucial factor in PMOP, as it generates excessive reactive oxygen species (ROS) that exacerbate PMOP. There is a certain interplay between SIRTs and OS. The reduced activity of SIRTs leads to intensified OS and the excessive accumulation of ROS. In return, ROS suppresses the AMPK signaling pathway and the synthesis of NAD+, which consequently diminishes the function of SIRTs. Natural SIRT activators and natural antioxidants, which are characterized by high safety, convenience, and minimal side effects, represent a potential therapeutic strategy for PMOP. This study aims to investigate the mechanisms of SIRTs and OS in PMOP and summarize potential therapeutic strategies to assist in the improvement of PMOP.

Natural traditional Chinese medicine products: emerging therapeutic targets for the treatment of osteoporosis

Osteoporosis is a systemic metabolic degenerative bone disease characterised by decreased bone mass, impaired bone microstructure, weakened bone strength and susceptibility to fracture. In China, the prevention and treatment of osteoporosis is faced with a high disease prevalence rate but low awareness, diagnosis and treatment rates. Bone resorption inhibitors and bone formation promoters often dominate osteoporosis treatment. Although conventional drugs can alleviate symptoms and reduce fracture risk, they often come with musculoskeletal, allergic and digestive side effects. Natural traditional Chinese medicine (TCM) products, known for their multi-targeting, high safety, efficacy and low cost, have been widely used in the treatment and prevention of osteoporosis in recent years and have gradually been recognised by many experts locally and abroad. This paper summarises recent research progress on natural TCM products in preventing and treating osteoporosis and provides a theoretical and experimental basis for the development of new drugs and the improvement of osteoporosis management.

Research on the role and mechanism of the PI3K/Akt/mTOR signalling pathway in osteoporosis

Osteoporosis is a systemic metabolic bone disease characterised mainly by reduced bone mass, bone microstructure degradation, and loss of bone mechanical properties. As the world population ages, more than 200 million people worldwide suffer from the pain caused by osteoporosis every year, which severely affects their quality of life. Moreover, the prevalence of osteoporosis continues to increase. The pathogenesis of osteoporosis is highly complex and is closely related to apoptosis, autophagy, oxidative stress, the inflammatory response, and ferroptosis. The PI3K/Akt/mTOR signalling pathway is one of the most crucial intracellular signal transduction pathways. This pathway is not only involved in bone metabolism and bone remodelling but also closely related to the proliferation and differentiation of osteoblasts, osteoclasts, and bone marrow mesenchymal stem cells. Abnormal activation or inhibition of the PI3K/Akt/mTOR signalling pathway can disrupt the balance between osteoblast-mediated bone formation and osteoclast-mediated bone resorption, ultimately leading to the development of osteoporosis. This review summarises the molecular mechanisms by which the PI3K/Akt/mTOR signalling pathway mediates five pathological mechanisms, namely, apoptosis, autophagy, oxidative stress, the inflammatory response, and ferroptosis, in the regulation of osteoporosis, aiming to provide a theoretical basis for the development of novel and effective therapeutic drugs and intervention measures for osteoporosis prevention and treatment.

Oxidative Balance Score Associated with Osteoporosis in Younger Women: A Cross-Sectional Analysis of the National Health and Nutrition Examination Survey 2013-2014 and 2017-2018 Data

OBJECTIVE

To explore the association between oxidative balance score (OBS) and osteoporosis risk, as well as to identify the specific population group.

METHODS

In this cross-sectional study, we included the data of 5,413 participants using the National Health and Nutrition Examination Survey of 2013-2014 and 2017-2018. Restricted cubic spline (RCS) curves, logistic regression models, trend tests, and stratification analyses were used to evaluate the association between the OBS and osteoporosis risk. Generalized linear models (GLM) were used to identify independent factors related to OBS. Finally, whether OBS played a mediating role in osteoporosis was evaluated using a mediation analysis.

RESULTS

Patients with osteoporosis had a lower OBS, and a high OBS score was associated with a decreased risk of osteoporosis (p < 0.05). Further stratification analysis revealed that the relationship between OBS and osteoporosis was robust in the three models in female patients aged < 70 years, which was validated using a trend test (p < 0.05). Age and sex were independent predictors of osteoporosis and the OBS. The OBS was a mediator in the association between sex, but not age, and disease.

CONCLUSION

Our findings indicate a negative relationship between OBS and osteoporosis risk, which was pronounced in younger women and individuals aged < 70 years. Moreover, sex may be related to osteoporosis through the regulation of OBS.

RANKL promotes MT2 degradation and ROS production in osteoclast precursors through Beclin1-dependent autophagy

ROS produced under oxidative stress are crucial for osteoclast differentiation. Metallothionein (MT) is a ROS-scavenging molecule. As a member of MT family, MT2 can clear ROS in osteoclast precursors (OCPs) and contributes to osteoclast differentiation. RANKL can promote OCP autophagy. Given the molecular-degrading effect of autophagy, the relationship between RANKL-dependent autophagy, MT2 and ROS during osteoclast differentiation is worth exploring. We depended in vitro RANKL administration and RANKL-overexpressing (Tg-RANKL) mice to observe the effects of RANKL on ROS production, MT2 protein expression, Beclin1 expression and autophagic activity in OCPs. Spautin1 was used to investigate the relationship between Beclin1-dependent autophagy and RANKL-regulated MT2 expression. Osteoclast-targeting MT2-cDNA-AAVs were applied to assess the therapeutic effect of MT2 on Tg-RANKL-related bone loss. The results showed that RANKL promoted ROS production but reduced MT2 protein expression in OCPs. RANKL also enhanced Beclin1 expression and LC3-puncta abundance. Decreased Beclin1 expression with spautin1 blocked RANKL-increased ROS production and osteoclast differentiation and recovered RANKL-decreased MT2 expression. MT2 selective overexpression with CD11b-promoter-MT2-cDNA-AAVs attenuated ROS production and osteoclastogenesis in Tg-RANKL mice and improved bone loss. Overall, RANKL can reduce MT2 protein expression through Beclin1-dependent autophagy, thereby promoting ROS production and osteoclast differentiation; this suggests that MT2-overexpressing small molecule drugs have the potential to treat RANKL-related bone loss.

Relation between bone mineral density and oxidative stress in Egyptian patients with chronic kidney disease: a cross sectional study

BACKGROUND

Chronic kidney disease (CKD) patients are prone to osteoporosis (OP) and they had significant oxidative stress. The relationship between oxidative stress (OS) and bone mineral density (BMD) in CKD is not entirely clear. The investigation of this relation is of pronounced importance in decreasing the occurrence of osteoporosis among CKD cases.

OBJECTIVES

To evaluate the association between BMD and OS in CKD patients.

METHODS

We performed a case-control study, including 150 adults with CKD (stage 1-5 according to Kidney Disease Improving Global Outcomes (KDIGO) classification, 2024) and 150 healthy controls. CKD patients were further subdivided to 3 subgroups based on estimated glomerular filtration rate: stage 1-2, stage 3-4 and stage 5. BMD at the lumbar spine (LS), femur neck (FN), and distal radius (DR) were measured using DEXA. Vitamin D and OS biomarkers including; 8-Hydroxy-2'-deoxyguanosine (8-OHdG) and Malondialdehyde (MDA) were measured. Paraoxonase1 (PON1) as a biomarker of antioxidant response was assessed. Statistical analysis was performed using the appropriate tests.

RESULTS

The CKD cases showed lower BMD T-Scores than healthy controls. Moreover, LS, DR, and FN BMDs were significantly different between CKD stages. Post hoc analyses showed higher LS, DR, and FN T-Scores in Stage I-II vs. Stage III-IV and Stage V. However, no significant differences were noted between stage III-IV and stage V for all sites. Significant increase in OS biomarkers (8-OHdG and MDA) while decreasing antioxidant activity (PON-1) with CKD severity were observed. There was a significant positive correlation between PON1and BMD while 8-OHdG and MDA had a negative correlation with BMD. We also observed significant positive correlations between 8-OHdG and MDA with alkaline phosphatase and phosphorus, while these markers had significant negative correlations with vitamin D and calcium. PON1 had a significantly positive correlation with vitamin D & calcium.

CONCLUSION

CKD patients suffer of OS. OS positively correlated with CKD severity. There is a negative relation between OS and BMD in CKD. OS might participate in the occurrence of OP in CKD.

B-Lymphoid Tyrosine Kinase Crosslinks Redox and Apoptosis Signaling Networks to Promote the Survival of Transplanted Bone Marrow Mesenchymal Stem Cells

Stress-induced apoptosis presents an obstacle to bone marrow mesenchymal stem cell (BMSC) transplantation to repair steroid-induced osteonecrosis of the femoral head (SONFH). Thus, appropriate intervention strategies should be explored to mitigate this. In our previous study, we discovered a new subgroup of BMSCs-the oxidative stress-resistant BMSCs (OSR-BMSCs)-which can survive the oxidative stress microenvironment in the osteonecrotic area, through a mechanism that currently remains unclear. In this study, we found that B-lymphoid tyrosine kinase (BLK) may be the crucial factor regulating the oxidative stress resistance of OSR-BMSCs, as it is highly expressed in these cells. Knockdown of BLK eliminated oxidative stress resistance, aggravated oxidative stress-induced apoptosis, reduced the survival of OSR-BMSCs in the oxidative stress microenvironment of the osteonecrotic area, and greatly weakened the transplantation efficacy of OSR-BMSCs for SONFH. By contrast, BLK was weakly expressed in oxidative stress-sensitive BMSCs (OSS-BMSCs). Overexpression of BLK in susceptible OSS-BMSCs allowed them to acquire oxidative stress resistance, inhibited oxidative stress-induced apoptosis, promoted their survival in the osteonecrotic area, and improved the transplantation efficacy of OSS-BMSCs for SONFH. Mechanistically, BLK concurrently activates redox and apoptotic signaling networks through its tyrosine kinase activity, which confers oxidative stress resistance to BMSCs and inhibits their stress-induced apoptosis of BMSCs. Herein, we report that OSR-BMSCs have intrinsic oxidative stress resistance that is conferred and mediated by BLK. This finding provides a potential new intervention strategy for improving the survival of transplanted BMSCs and the therapeutic efficacy of BMSC transplantation for SONFH.

Advances in Plant-Derived Extracellular Vesicle Extraction Methods and Pharmacological Effects

Extracellular vesicles (EVs) are those with a double-membrane structure that contains proteins, lipids, nucleic acids, and other biologically active substances that play an important role in cell-cell and cell-environment communication. They have also become an important mechanism for exchanging biologically active substances for cellular molecules. As many studies on EVs have been conducted, plant-derived extracellular vesicles (PDEVs) have also started attracting attention. The biological activity and stability of PDEVs are closely related to the extraction and separation methods, and choosing a separation method that meets the requirements of PDEVs is important. The extraction methods of PDEVs include ultracentrifugation, ultrafiltration, size-exclusion chromatography, etc. In recent years, it has been found through research that PDEVs possess biological properties, such as anti-inflammatory, anti-cancer, and anti-infective properties, and that they show unique advantages as therapeutic agents and drug carriers. Therefore, we have collected the scientific literature related to EVs derived from more than a dozen fruits and vegetables, and summarized and analyzed their extraction, separation, and roles in disease treatment, aiming to provide reference and inspiration for the in-depth study of the efficacy of new drugs.

Mechanisms and structure-activity relationships of natural polysaccharides as potential anti-osteoporosis agents: A review

In recent years, polysaccharides derived from natural sources have garnered significant attention due to their safety and potential anti-osteoporotic effects. This review provides a comprehensive overview of the sources, distribution, structures, and mechanisms of anti-osteoporosis polysaccharides, as well as an investigation into their structure-activity relationships. Over thirty distinct, homogenous polysaccharides with anti-osteoporosis properties have been extracted from natural sources, primarily categorized as glucans, fructans, galactomannans, glucomannans, and various other heteropolysaccharides. Natural polysaccharides can effectively enhance osteoblast differentiation and mineralization while suppressing osteoclast activation, with the mechanism regulated by the BMP/SMAD/RUNX2, Wnt/Catenin, OPG/RANKL/RANK, and TLR2/NF-κB/NFATc1 signaling pathways. Furthermore, polysaccharides contribute to the prevention of osteoporosis by mitigating oxidative stress, decreasing inflammation, and modulating the gut microbiota. This review also summarizes the relationship between the monosaccharide composition, molecular weight, and glycosidic bond type of polysaccharides and their anti-osteoporotic activity. A comprehensive summary and analysis of the existing deficiencies and challenges in the research of anti-osteoporotic polysaccharides is also concluded. This review may serve as a significant reference for the discovery and utilization of naturally derived anti-osteoporotic polysaccharides in the pharmaceutical and health industries.

Protein bioactive complexes promote osteogenesis under microgravity environment

The space microgravity environment and cosmic radiation pose a significant threat to musculoskeletal health, particularly bone mass. However, the critical mechanism underlying space-induced bone loss and its relation to cellular oxidative stress remains unclear. Currently used bone-loss-reversing drugs face limitations like poor efficacy and metabolic defects. Herein, we revealed that simulated microgravity (SMG) induces reactive oxygen species (ROS), negatively impacting osteoblasts, causing cytoskeletal damage, and downregulating osteogenic genes. To combat this, we designed protein-zein nanocages loaded with a chimeric non-enzymatic cocktail (ZNAC) containing ascorbic acid, resveratrol, luteolin, coenzyme Q, and glutathione. These nanocages (~200 nm) demonstrated excellent stability, biocompatibility, and antioxidant properties compared to free drugs. We investigated the effects of ZNAC under SMG using two experimental models: MC3T3 pre-osteoblast/MG63 osteoblasts and regenerating zebrafish scales that represent compositional and physiological/pathophysiological analogy with mammalian system. ZNAC effectively reduced SMG-induced ROS, preserved cytoskeletal integrity, and enhanced alkaline phosphatase (ALP) activity along with the expression of osteogenic genes such as RUNX2 and Col1A1. In zebrafish scales, it increased osteogenic gene expression, calcification, and the calcium/phosphorus ratio, indicating enhanced scale regeneration. These findings suggest that ZNAC is a promising candidate for bone regeneration, offering potential solutions for maintaining astronaut health during extended space missions.

Supersulfides contribute to joint homeostasis and bone regeneration

The physiological functions of supersulfides, inorganic and organic sulfides with sulfur catenation, have been extensively studied. Their synthesis is mainly mediated by mitochondrial cysteinyl-tRNA synthetase (CARS2) that functions as a principal cysteine persulfide synthase. This study aimed to investigate the role of supersulfides in joint homeostasis and bone regeneration. Using Cars2AINK/+ mutant mice, in which the KIIK motif of CARS2 essential for supersulfide production was replaced with AINK, we evaluated the role of supersulfides in fracture healing and cartilage homeostasis during osteoarthritis (OA). Tibial fracture surgery was performed on the wild-type (Cars2+/+) and Cars2AINK/+ mice littermates. Bulk RNA-seq analysis for the osteochondral regeneration in the fracture model showed increased inflammatory markers and reduced osteogenic factors, indicative of impaired bone regeneration, in Cars2AINK/+ mice. Destabilization of the medial meniscus (DMM) surgery was performed to produce the mouse OA model. Histological analyses with Osteoarthritis Research Society International and synovitis scores revealed accelerated OA progression in Cars2AINK/+ mice compared with that in Cars2+/+ mice. To assess the effects of supersulfides on OA progression, glutathione trisulfide (GSSSG) or saline was periodically injected into the mouse knee joints after the DMM surgery. Thus, supersulfides derived from CARS2 and GSSSG exogenously administered significantly inhibited inflammation and lipid peroxidation of the joint cartilage, possibly through suppression of ferroptosis, during OA development. This study represents a significant advancement in understanding anti-inflammatory and anti-oxidant functions of supersulfides in skeletal tissues and may have a clinical relevance for the bone healing and OA therapeutics.

Plasma levels of amino acids and osteoporosis: a cross-sectional study

The role of amino acids (AAs) with bone health is still controversial. We examined the association between AAs and osteoporosis in a cross-sectional study of 135 participants aged 45 years or older from the Second Hospital of Jilin University. Plasma AAs were measured with targeted quantitative methodology. We measured bone mineral density (BMD) with dual energy x-ray absorptiometry, and osteoporosis was defined as a T-score ≤ -2.5. We estimated odds ratios (OR) and corresponding 95% confidence intervals (CIs) for the associations between AAs (per 1 standard deviation increase) with osteoporosis. Approximately 18.5% of participants (n = 25) had osteoporosis. Total (adjusted β = 0.052; P = 0.002) and non-essential AA (adjusted β = 0.064; P = 0.002) levels were associated with femoral neck BMD T-scores. Greater levels of total (adjusted OR: 0.734; 95% CI: 0.655-0.821), essential (adjusted OR: 0.763; 95% CI: 0.623-0.934) and non-essential AAs (adjusted OR: 0.721; 95% CI: 0.629-0.826) were associated with lower odds of osteoporosis. Higher tryptophan (adjusted OR: 0.498; 95% CI: 0.281-0.882), cysteine (adjusted OR: 0.561; 95% CI: 0.321-0.983), glycine (adjusted OR: 0.513; 95% CI: 0.285-0.922), and ornithine levels (adjusted OR: 0.581; 95% CI: 0.345-0.978) were associated with reduced osteoporosis risk. Higher AA levels were associated with higher femoral neck BMD, and lower odds of osteoporosis.

Perspectives of exosomal ncRNAs in the treatment of bone metabolic diseases: Focusing on osteoporosis, osteoarthritis, and rheumatoid arthritis

Bone metabolic disorders, constituting a group of prevalent and grave conditions, currently have a scarcity of therapeutic alternatives. Over the recent past, exosomes have been at the forefront of research interest, owing to their nanoparticulate nature and potential for therapeutic intervention. ncRNAs are a class of heterogeneous transcripts that they lack protein-encoding capacity, yet they can modulate the expression of other genes through multiple mechanisms. Mounting evidence underscores the intricate role of exosomes as ncRNAs couriers implicated in the pathogenesis of bone metabolic disorders. In this review, we endeavor to elucidate recent insights into the roles of three ncRNAs - miRNAs, lncRNAs, and circRNAs - in bone metabolic ailments such as osteoporosis, osteoarthritis, and rheumatoid arthritis. Additionally, we examine the viability of exosomal ncRNAs as innovative, cell-free modalities in the diagnosis and therapeutic management of bone metabolic disorders. We aim to uncover the critical function of exosomal ncRNAs within the context of bone metabolic diseases.

Association between dietary carotenoid intake and vertebral fracture in people aged 50 years and older: a study based on the National Health and Nutrition Examination Survey

This study discussed the association between dietary intake of carotenoids and vertebral fractures by analyzing the target data, concluding a result of negative association and providing valuable information on vertebral fracture.

OBJECTIVE

This study is to explore the association between dietary intake of carotenoids and vertebral fractures.

METHODS

Data of individuals aged ≥ 50 years from the 2013-2014 National Health and Nutrition Examination Survey (NHANES) database were used in this cross-sectional study. Information on dietary carotenoid intake was obtained from the first 24-h dietary recall interview. Vertebral fractures were assessed using dual-energy x-ray absorptiometry (DXA). The weighted multivariable logistic regression model was established to assess the association between dietary carotenoid intake and risk of vertebral fracture. Subgroup analysis of fracture history and menopausal status was performed for further analysis of this relationship.

RESULTS

Of the 2053 eligible study subjects, there were 1021 men and 1032 women. Increased β-carotene intake was associated with decreased odds of vertebral fracture in women (odds ratio (OR) = 0.77, 95% confidence interval (CI) 0.60-0.99, P = 0.047), after adjusting for covariates. In men without a history of fracture, lutein and zeaxanthin intake was negatively associated with increased odds of vertebral fracture (OR = 0.70, 95% CI 0.50-0.99, P = 0.048). In women without a history of fracture, increased β-carotene intake was associated with decreased odds of vertebral fracture (OR = 0.78, 95% CI 0.61-0.99, P = 0.047). In postmenopausal women, β-carotene intake was also negatively associated with increased odds of vertebral fracture (OR = 0.77, 95% CI 0.60-0.99, P = 0.048).

CONCLUSION

This research concludes a negative association between dietary carotenoid intake, especially β-carotene, and vertebral fractures in women, revealing a potential dietary prevention tactic for vertebral fractures in the future.

ROS-responsive hydrogel for bone regeneration: Controlled dimethyl fumarate release to reduce inflammation and enhance osteogenesis

Large bone defects, often arising from trauma or infection, pose a considerable therapeutic challenge due to their limited capacity for spontaneous healing, thus requiring bone graft materials for effective reparative procedures. The persistence of inflammation and elevated levels of reactive oxygen species (ROS) within these defect sites significantly impede bone regeneration process. Addressing this, an injectable hydrogel system with ROS-responsive functionality is developed, specifically tailored to the high ROS microenvironment characteristic of bone defects. This system incorporates hyaluronic acid functionalized with dopamine to introduce catechol moieties, and employs 4-formylphenylboronic acid as a crosslinking agent to form a dynamic hydrogel matrix (HAC) with carboxymethyl chitosan. The HAC hydrogel serves as a carrier for dimethyl fumarate (DMF), a compound with established anti-inflammatory and antioxidant effects, enabling its controlled release in response to ROS levels. Herein, we investigated the physicochemical properties of DMF loaded hydrogel (DHAC) by microstructure observation, in vitro degradation assay, self-healing test, injectability experiments, DMF drug release assay. Meanwhile, we systematically investigated its effects on inflammation, intracellular ROS, and osteogenesis. Consequently, the DHAC significantly reduced pro-inflammatory cytokines secreted by RAW264.7 cells and scavenged intracellular ROS in MC3T3 cells. This effect was accompanied by an augmentation in the osteogenic potential of MC3T3 cells and a promotion in the repair of cranial defects in rats. The DHAC, which exhibits anti-inflammatory, antioxidant, and osteogenic activity, hold great potential as an effective strategy for the management of large bone defects. STATEMENT OF SIGNIFICANCE: Here, a novel dimethyl fumarate-loaded ROS-responsive hydrogel system was developed for effective treatment of large bone defects. Our findings demonstrated that the hydrogel not only promotes bone regeneration but also controls inflammation, addressing two critical challenges in bone healing. Comprehensive evaluations show significant improvements in bone formation and reduction of pro-inflammatory cytokines in animal models. Additionally, the hydrogel exhibits excellent reactive oxygen species scavenging ability, effectively modulating oxidative stress in the bone defect microenvironment. Findings suggest the hydrogel system may serve as a promising therapeutic strategy for clinical management of critical-sized bone defects.

Impact of the dietary antioxidant index on bone mineral density gain among mexican adults: a prospective study

In the Mexican population, low dietary antioxidant intake (DAI) is associated with reduced bone mineral density (BMD). A decline in DAI over time further contributes to BMD loss, particularly at the total hip, femoral neck, and lumbar spine, with a more pronounced effect in women over 45 years old.

PURPOSE

Bone remodeling, balancing resorption and formation, is crucial for bone health. Aging shifts this balance, reducing BMD and increasing osteoporosis risk. Reactive oxygen species (ROS) contribute to bone loss through oxidative stress. Antioxidants may help mitigate this damage, but their impact on BMD in populations with inadequate nutrient intake, like Mexicans, needs to be better understood. This study explores the association between DAI changes and BMD in a Mexican population.

METHODS

Data were sourced from the Health Worker Cohort Study (HWCS), including 1,318 participants (aged ≥ 20) with BMD measurements and complete dietary information at two time points. The study employed a longitudinal design was used, whit data from two waves of the study (2010-2012 and 2017-2019), providing a median follow-up time of 6.4 years for men and 6.8 years for women. Dietary antioxidant intake was assessed using a validated Food Frequency Questionnaire for the Mexican diet. BMD was measured at the femoral neck, total hip, and lumbar spine using dual-energy X-ray absorptiometry (DEXA). Fixed-effects regression models were applied to analyze the association between DAI and BMD at different sites, adjusting for time-varying covariates.

RESULTS

Changes in DAI scores were associated with lower BMD at various sites. Each unit decrease in DAI over time was associated with a BMD loss of -0.002,-0.004 g/cm2 at the total hip, femoral neck, and lumbar spine. Notable declines were observed in women, particularly those over 45 years old, where specific antioxidant components, like zinc, magnesium, and selenium, were linked to lower BMD.

CONCLUSION

This study underscores the role of reduced dietary antioxidant intake in contributing lower BMD, particularly among older adults. Diets low in antioxidant may increase the risk of osteoporosis, especially in populations with insufficient nutrient intake.

Association between serum uric acid levels and bone mineral density in Chinese and American: a cross-sectional study

Despite extensive studies conducted on the relationship between serum uric acid (UA) and bone mineral density (BMD), their association remains controversial. In this study, we investigated whether UA levels are independently associated with BMD in Chinese and American populations to elucidate their association. Herein, the data of 12,344 individuals (age > 20 years) from the National Health and Nutrition Examination Survey (2005-2018) and those of 768 individuals from the inpatient medical records and physical examination center systems of the Tertiary Class A Hospital (2021-2023) from China were included. The association between UA and BMD was analyzed by employing multivariate regression models with covariate adjustments. In addition, population description, stratified analysis, single-factor analysis, smooth-curve fitting, and threshold and saturation effect analyses were performed. After covariate adjustments, UA exhibited an association with BMD of the femur (β = 0.008, 95% confidence interval [CI] 0.001-0.015, P = 0.02), femoral neck (β = 0.011, 95% CI 0.004-0.018, P = 0.002), and lumbar spine (β = 0.014, 95% CI 0.06-0.022, P < 0.001) in American subjects. Similarly, UA exhibited association with BMD of the femur (β = 0.079, 95% CI 0.042-0.117, P < 0.001), femoral neck (β = 0.171, 95% CI 0.121-0.22, P < 0.001), and lumbar spine (β = 0.052, 95% CI 0.007-0.097, P = 0.024) in Chinese subjects. Notably, the relationship between UA levels and BMD was nonlinear. The saturated utility values for determining the UA level with BMD of the femur and femoral neck using a two-stage linear regression model were 429.9 and 468 μmol/L, respectively, in the Chinese population. In the American population, the saturated utility values of UA level with BMD of the femur, femoral neck, and lumbar spine were 410.4, 410.4, and 452 μmol/L, respectively. Altogether, the present findings suggested a positive association between the UA levels and overall BMD in adults, implying that maintaining saturated UA levels can facilitate osteoporosis prevention.China Clinical Trials Registry: MR-51-23-051741. https://www.medicalresearch.org.cn/search/research/researchViewid=c0e5f868-eca9-4c68-af58-d73460c34028 .

Effect of Bacillus subtilis isolated from yaks on D-galactose-induced oxidative stress and hepatic damage in mice

Acute hepatic injury is a severe condition that is always accompanied by oxidative stress and inflammation, seriously threatening the health of the host. Probiotics have been shown to be involved in the regulation of antioxidant system and gut microbiota activity, but studies on the effects of yak derived Bacillus subtilis (B. subtilis) on acute liver injury and oxidative stress remain scarce. Here, we aim to explore the ameliorative effects of B. subtilis isolated from yaks on oxidative stress and hepatic injury caused by D-galactose, as well as the underlying processes. Results indicated that B. subtilis administration, particularly the BS3, significantly mitigated hepatic damage induced by D-galactose in mice as evidenced by ameliorating liver tissue damage as well as decreasing ALT (p < 0.05) and AST (p < 0.05) levels. Additionally, the B. subtilis intervention was demonstrated to enhance the antioxidant system in D-galactose-exposed mice, as manifested by increased T-AOC and SOD, alongside a decrease in MDA levels (p < 0.05). Meanwhile, B. subtilis intervention could effectively mitigate oxidative damage via modulating the Keap1/Nrf2 signaling pathway. Importantly, B. subtilis exhibited a pronounced protective effect against D-galactose-induced intestinal barrier dysfunction through improving tight junction proteins. The gut microbiota results suggest that BS3 alters the abundance of some gut flora such as Firmicutes phylum and Oscillibacter and Lachnospiraceae_NK4A136 genera, which affects the composition of the gut microbiota and reverses the decrease in the microbial richness index in mice. In summary, these findings demonstrated that B. subtilis isolated from yaks serve as a promising candidate to ameliorate oxidative damage and hepatic injury. Meanwhile, the positive regulation effect of B. subtilis on gut microbiota and intestinal mucosal barrier may be one of its underlying mechanisms to alleviate oxidative stress and hepatic injury.

Preparation and properties of raspberry functional chewable tablets

Raspberry possesses several health benefits such as antitumor, antioxidant, and blood sugar-regulating activities. In order to improve the use value of raspberries, the optimal preparation process of raspberry chewable tablets (RCT) and its physical, chemical, antioxidant, and hypoglycemic properties were investigated in this research. The optimum formulation of RCT was determined as 39.1% raspberry powder, 13.1% red beet root powder, 9.8% corn starch, 15% microcrystalline cellulose, 14% mannitol, 1% magnesium stearate, and 8% ethanol (75%) by single-factor experiment and response surface methodology using sensory evaluation score and hardness as parameters. RCT prepared using the optimal formulation had a hardness of 47.33 ± 2.31 N, brittleness of 0.33%, weight of 1.00 ± 0.03 g, and a color difference ΔE = 0.427. The total phenolic and total flavonoid contents of RCT were 18.610 ± 0.483 mg/g and 3.885 ± 0.061 mg/g, respectively. Meanwhile, seven phenolic compounds in RCT were determined by high-performance liquid chromatography. Free radical scavenging abilities ((1,1-diphenyl-2-picrylhydrazyl, DPPH), (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid), ABTS), and ·OH), ferric ion-reducing antioxidant power and cell tests proved the significant antioxidant ability of RCT. The obvious inhibitory activities of RCT on α-glucosidase and α-amylase reflected its hypoglycemic potential. This study provided an important basis for the development of raspberry functional foods with antioxidant and blood glucose regulating potential.

5,7-Dihydroxy-4-Methylcoumarin enhances osteogenesis and ameliorates osteoporosis via the AKT1 pathway

Osteoporosis is a chronic disease distinguished by decreased bone density and degradation of bone microstructure, frequently linked with inflammation and oxidative stress, both of which contribute to the acceleration of bone resorption. The compound 5,7-Dihydroxy-4-methylcoumarin (D4M) present in Artemisia dracunculus exhibits significant antioxidant and anti-inflammatory properties. Nonetheless, the potential anti-osteoporotic effects of D4M, along with the molecular targets and mechanisms responsible for these effects, have not been studied. This study aims to assess the impact of D4M on osteoblastogenesis and glucocorticoid-induced osteoporosis while examining the potential underlying mechanisms. We examined the effects of varying concentrations of D4M on the proliferation and differentiation of MC3T3-E1 cells. Additionally, in vivo experiments were carried out using a glucocorticoid-induced zebrafish osteoporosis model to evaluate the effects of D4M on vertebral bone density and osteogenic markers. Target prediction and molecular docking analyses were conducted to investigate the binding interactions between D4M and its target proteins. D4M showed a significant enhancement of MC3T3-E1 cell proliferation and differentiation within the concentration range of 10 to 40 μM, with the greatest increase in mineralization noted at 20 μM. Furthermore, in the zebrafish osteoporosis model, treatment with 20 μM D4M resulted in a significant improvement in vertebral bone density and the restoration of osteoblast-specific marker expression. Ligand-based target prediction identified AKT1 as a potential target for D4M, and molecular docking highlighted the binding interactions between D4M and AKT1 phosphorylation sites. Co-treatment with the AKT1 inhibitor A-443654 abolished the anti-osteoporotic effects of D4M. These findings demonstrate that D4M enhances osteoblast differentiation and mitigates osteoporosis through its interaction with AKT1, suggesting its potential as a therapeutic agent for treating osteoporosis.

Ellagic acid prevents ovariectomy-induced bone loss and attenuates oxidative damage of osteoblasts by activating SIRT1

Oxidative stress has been implicated as a causative factor for the development and progression of osteoporosis(OP). Ellagic acid (EA), a natural polyphenol, presents anti-oxidative and anti-inflammatory properties. However, EA's role and molecular mechanism in osteoblasts have not yet been elucidated. In this study, exogenous supplementation with EA restored the osteoporotic bone defects in ovariectomized (OVX)-induced osteoporotic mice. Also, EA inhibited the H2O2-induced apoptosis of primary osteoblasts, prevented the production of reactive oxygen species, and restored the bone-forming potential of osteoblasts. Furthermore, EA was revealed to activate Sirtuin1 (SIRT1) and its downstream Nrf2/Heme Oxygenase 1 (HO-1) signaling pathway, and EX527 (a SIRT1 inhibitor) partially counteracted the effect of EA on bone loss. The findings suggest that EA protects against osteoporotic bone loss by activating SIRT1 and its downstream Nrf2/HO-1 signaling pathway, providing novel insights into the potential of EA as a treatment agent for osteoporosis-related bone metabolism diseases.

Adherence to a healthy dietary pattern mitigates the detrimental associations between osteosarcopenic adiposity and both all-cause mortality and life expectancy: a cohort study

Background and aims: To determine the associations between osteosarcopenic adiposity (OSA) and both all-cause mortality and life expectancy, and to investigate whether adherence to a healthy diet can modify these associations. Methods: Utilizing data obtained from 201 223 UK Biobank participants, we assessed body composition for OSA and a healthy diet score was used to assess dietary quality. Results: Compared to participants with no body composition abnormality, the adjusted HRs (95% CIs) of all-cause mortality for those with 1, 2, and 3 (OSA) abnormalities were 1.13 (1.08, 1.18), 1.28 (1.21, 1.35), and 2.01 (1.58, 2.56) after adjustments, respectively. Compared with participants with no body composition abnormality, OSA patients with poor dietary patterns had a higher risk of all-cause mortality (HR = 2.92, 95% CI: 1.96, 4.36) than those with medium (HR = 1.73, 95% CI: 1.27, 2.37) and healthy dietary patterns (HR = 1.39, 95% CI: 0.34, 5.60). Specifically, a lower intake of fish and a higher intake of processed meat contributed to such different associations. Compared with participants without body composition abnormality, those with 1, 2, and 3 (OSA) body composition abnormalities had 0.31 (95% CI: -0.07, 0.69), 0.62 (95% CI: 0.16, 1.09) and 3.03 (95% CI: 1.05, 5.00) years of reduced life expectancy at age 45 years. Conclusions: Body composition abnormality, particularly OSA, is associated with both increased risk of all-cause mortality and reduced life expectancy. Nevertheless, it is noteworthy that adopting a healthy dietary pattern appears to mitigate these associations.

Synthetic nanoparticles functionalized with cell membrane-mimicking, bone-targeting, and ROS-controlled release agents for osteoporosis treatment

Postmenopausal osteoporosis is a common degenerative disease, with suboptimal clinical outcomes. The targets of current therapeutic agents are both nonspecific and diverse. We synthesized a novel nanoparticle (NP), ALN@BMSCM@PLGA-TK-PEG-SS31. After intravenous injection, the NP evaded immune phagocytosis, targeted bone tissue, and efficiently downregulated bone reactive oxygen species (ROS) generation. The core PLGA-TK-PEG-SS31 NP was ∼100 nm in diameter. The TK chemical bond breaks on exposure to ROS, releasing the novel mitochondrion-targeting peptide SS31. Outer bone marrow mesenchymal stem cell membranes (BMSCMs) were used to coat the NP with surface proteins to ensure membrane functionality. The circulation time was prolonged and immune phagocytosis was evaded. Embedding the DSPE-PEG-ALN lipid within the cell membrane enhanced the bone-targeting ability of the NP. Our results suggest that ALN@BMSCM@PLGA-TK-PEG-SS31 exerted dual effects on bone tissue in vitro, significantly inhibiting RANKL-induced osteoclastogenesis in the presence of H2O2 and promoting osteogenic differentiation in BMSCs. In a mouse model of ovariectomy-induced osteoporosis, ALN@BMSCM@PLGA-TK-PEG-SS31 significantly ameliorated oxidative stress and increased bone mass with no notable systemic side effects. These results suggest that ALN@BMSCM@PLGA-TK-PEG-SS31 is a promising treatment for osteoporosis.

Correlation between uric acid levels and bone mineral density in patients with type 2 diabetes mellitus: a systematic review and meta-analysis

Purpose

To explore the controversial relationship between uric acid (UA) levels and bone mineral density (BMD) in patients with type 2 diabetes mellitus (T2DM).

Patients and methods

The PubMed, Embase, and Cochrane Library databases were searched using keywords and related words. Study quality was evaluated using the Newcastle-Ottawa Scale. Studies retrieved in the literature search were systematically screened to extract information and data based on predefined inclusion and exclusion criteria. RevMan version 5.3 and Stata Release 13.0 were used for statistical analysis. Results are expressed as mean difference (MD) and corresponding 95% confidence interval (CI). Heterogeneity was evaluated using the I2 and Q tests.

Results

This meta-analysis included 10 studies comprising 5,717 patients with T2DM. Study quality ranged from moderate to high. Results of comparative analyses were as follows: normal BMD versus (vs.) osteoporosis (OP) in females, MD -13.83 μmol/L (95% CI -41.69 to 14.03); I2 = 7%; P=0.30); normal BMD vs. osteopenia in females, MD -12.41 μmol/L (95% CI -37.81 to 12.99; I2 = 0%; P=0.92); normal BMD vs. abnormal BMD (osteopenia/OP), MD -23.82 μmol/L (95% CI -33.50 to -14.13; I2 = 0%; P=0.44); and osteopenia vs. OP, MD -22.35 μmol/L (95% CI -29.55 to -15.15; I2 = 5%; P=0.39). No publication bias was observed.

Conclusion

Compared with normal BMD, abnormal BMD (osteopenia/OP) was associated with lower UA levels. Compared with osteopenia, OP also showed lower UA.Systematic review registration.

Association of dietary niacin intake with osteoporosis in the postmenopausal women in the US: NHANES 2007-2018

Background

Elderly individuals with inadequate vitamin B level are at increased risk of degenerative conditions, notably cardiovascular disorders, cognitive impairments, and osteoporosis. The relationship between niacin (vitamin B3) consumption and osteoporosis risk remains a subject of debate. This study aimed to clarify the relationship between dietary niacin intake and the incidence of osteoporosis in postmenopausal women aged ≥50 years.

Methods

In this study, we gathered details on participants' bone mineral density, osteoporosis status, dietary niacin intake, and several other critical variables. Multivariate logistic regression models were constructed to determine the association between dietary niacin intake and the incidence of osteoporosis. Restricted cubic splines were employed to further assess the linearity and explore the shape of the dose-response associations. Additionally, we performed stratified and interaction analyses to illustrate the stability of the observed relationships across different subgroups.

Results

After adjusting for all covariates, there was a significant inverse association with osteoporosis (OR = 0.87; 95% CI: 0.77-0.97; p = 0.016). A negative relationship was observed between dietary niacin intake and the risk of osteoporosis (nonlinear: p = 0.672). While stratified analyses revealed some differences in the association between dietary niacin intake and osteoporosis risk, these differences were not statistically significant.

Conclusion

Dietary niacin intake exhibited an inverse correlation with the incidence of osteoporosis. The risk of osteoporosis was significantly reduced by 13% with every 10 mg/day increase in daily dietary niacin consumption among postmenopausal women.

Application and progress of 3D printed biomaterials in osteoporosis

Osteoporosis results from a disruption in skeletal homeostasis caused by an imbalance between bone resorption and bone formation. Conventional treatments, such as pharmaceutical drugs and hormone replacement therapy, often yield suboptimal results and are frequently associated with side effects. Recently, biomaterial-based approaches have gained attention as promising alternatives for managing osteoporosis. This review summarizes the current advancements in 3D-printed biomaterials designed for osteoporosis treatment. The benefits of biomaterial-based approaches compared to traditional systemic drug therapies are discussed. These 3D-printed materials can be broadly categorized based on their functionalities, including promoting osteogenesis, reducing inflammation, exhibiting antioxidant properties, and inhibiting osteoclast activity. 3D printing has the advantages of speed, precision, personalization, etc. It is able to satisfy the requirements of irregular geometry, differentiated composition, and multilayered structure of articular osteochondral scaffolds with boundary layer structure. The limitations of existing biomaterials are critically analyzed and future directions for biomaterial-based therapies are considered.

Hyperbaric Oxygen Therapy for the Treatment of Bone-Related Diseases

Hyperbaric oxygen therapy (HBOT) is a therapeutic modality that enhances tissue oxygenation by delivering 100% oxygen at pressures greater than 1 absolute atmosphere. In recent years, HBOT has shown considerable potential in the treatment of bone diseases. While excess oxygen was once thought to induce oxidative stress, recent studies indicate that when administered within safe limits, HBOT can notably promote bone healing and repair. Extensive basic research has demonstrated that HBOT can stimulate the proliferation and differentiation of osteoblasts and encourage bone angiogenesis. Furthermore, HBOT has been shown to exert a beneficial influence on bone metabolism by modulating the inflammatory response and redox status. These mechanisms are closely related to core issues of bone biology. Specifically, in the context of fracture healing, bone defect repair, and conditions such as osteoporosis, HBOT targets the key bone signaling pathways involved in bone health, thereby exerting a therapeutic effect. Several clinical studies have demonstrated the efficacy of HBOT in improving bone health. However, the optimal HBOT regimen for treating various bone diseases still requires further definition to expand the indications for its clinical application. This paper outlines the mechanisms of HBOT, focusing on its antioxidant stress, promotion of bone vascularization, and anti-inflammatory properties. The paper also describes the application of HBOT in orthopedic diseases, thereby providing a scientific basis for the development of precise and personalized HBOT treatment regimens in clinical orthopedics.

The mechanism of action of indole-3-propionic acid on bone metabolism

Indole-3-propionic acid (IPA), a metabolite produced by gut microbiota through tryptophan metabolism, has recently been identified as playing a pivotal role in bone metabolism. IPA promotes osteoblast differentiation by upregulating mitochondrial transcription factor A (Tfam), contributing to increased bone density and supporting bone repair. Simultaneously, it inhibits the formation and activity of osteoclasts, reducing bone resorption, possibly through modulation of the nuclear factor-κB (NF-κB) pathway and downregulation of osteoclast-associated factors, thereby maintaining bone structural integrity. Additionally, IPA provides indirect protection to bone health by regulating host immune responses and inflammation via activation of receptors such as the Aryl hydrocarbon Receptor (AhR) and the Pregnane X Receptor (PXR). This review summarizes the roles and signaling pathways of IPA in bone metabolism and its impact on various bone metabolic disorders. Furthermore, we discuss the therapeutic potential and limitations of IPA in treating bone metabolic diseases, aiming to offer novel strategies for clinical management.

Nonlinear Association Between Serum Uric Acid and Femoral Neck Bone Mineral Density in Male Patients with Metabolic Dysfunction-Associated Fatty Liver Disease

Purpose

To investigate the relationship between serum uric acid (SUA) levels and femoral neck bone mineral density (BMD) in patients with metabolic dysfunction-associated fatty liver disease (MAFLD).

Patients and Methods

This cross-sectional study included 597 adult inpatients with type 2 diabetes mellitus and ultrasonography-confirmed fatty liver disease. Participants were stratified into tertiles based on femoral neck BMD. Gender-stratified linear regression analyses were performed to assess the relationship between SUA and femoral neck BMD. Nonlinear associations were explored using generalized additive models and two-piece linear regression.

Results

No significant linear association was observed between SUA and femoral neck BMD in either gender (all P > 0.05). However, after adjusting for confounders, a nonlinear relationship was identified in male patients, with a threshold at 388 μmol/L. The effect sizes for SUA levels below and above this threshold were 0.001 (95% CI: 0.000 to 0.002, P = 0.008) and -0.000 (95% CI: -0.002 to 0.000, P = 0.117), respectively. No nonlinear relationship was observed in female patients.

Conclusion

In male MAFLD patients, SUA levels exhibit a nonlinear relationship with femoral neck BMD, with a positive association observed between 300 μmol/L and 388 μmol/L. This relationship was not observed in female patients, suggesting gender-specific effects of SUA on bone health in MAFLD.

Serum Uric Acid and Bone Health in Middle-Aged and Elderly Hypertensive Patients: A Potential U-Shaped Association and Implications for Future Fracture Risk

BACKGROUND

The influence of serum uric acid (SUA) on bone metabolism, as suggested by previous studies, remains a contentious issue. SUA plays a complex role in bone health and hypertension, making it challenging to discern its impact on the skeletal status of middle-aged and elderly hypertensive patients. This study aims to elucidate the effects of SUA on bone health, with a particular focus on its association with osteoporosis and the risk of fractures.

METHODS

Multiple linear regression analyzed SUA levels against bone mineral density (BMD) and future fracture risk. Additionally, multivariate logistic regression was used to examine the association between SUA and osteoporosis. Dose-response relationship analysis was conducted using generalized smooth curve fitting (GSCF) and restricted cubic spline (RCS) methods.

RESULTS

With the exception of the total femur region, SUA and BMD showed a positive connection. GSCF analysis revealed an inverted U-shaped relationship between SUA and BMD, alongside a U-shaped trend with FRAX scores. Moreover, RCS analysis indicated a U-shaped relationship between osteoporosis risk and SUA levels, with higher risks identified in the first and third tertiles compared to the second tertile.

CONCLUSIONS

In individuals with middle-aged and older hypertension, SUA is substantially linked to bone health. The identification of an inverted U-shaped relationship with BMD and U-shaped relationships with FRAX scores and osteoporosis risk highlights the nuanced influence of SUA. These findings suggest that both low and high SUA levels may adversely affect bone health, emphasizing the need for further research.

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.

Construction of an Oxidative Stress Risk Model to Analyze the Correlation Between Liver Cancer and Tumor Immunity

BACKGROUND

Hepatocellular carcinoma (HCC) remains one of the most lethal cancers globally. Despite advancements in immunotherapy, the prognosis for patients with HCC continues to be poor. As oxidative stress plays a significant role in the onset and progression of various diseases, including metabolism-related HCC, comprehending its mechanism in HCC is critical for effective diagnosis and treatment.

METHODS

This study utilized the TCGA dataset and a collection of oxidative stress genes to identify the expression of oxidative stress-related genes in HCC and their association with overall survival using diverse bioinformatics methods. A novel prognostic risk model was developed, and the TCGA cohort was divided into high-risk and low-risk groups based on each tumor sample's risk score. Levels of immune cell infiltration and the expression of immune checkpoint-related genes in different risk subgroups were analyzed to investigate the potential link between tumor immunity and oxidative stress-related features. The expression of model genes in actual samples was validated through immunohistochemistry, and their mRNA and protein expression levels were measured in cell cultures.

RESULTS

Four oxidative stress-related genes (EZH2, ANKZF1, G6PD, and HMOX1) were identified and utilized to create a predictive risk model for HCC patient overall survival, which was subsequently validated in an independent cohort. A correlation was found between the expression of these prognostic genes and the infiltration of tumor immune cells. Elevated expression of EZH2, ANKZF1, G6PD, and HMOX1 was observed in both HCC tissues and cell lines.

CONCLUSION

The combined assessment of EZH2, ANKZF1, G6PD, and HMOX1 gene expression can serve as an oxidative stress risk model for assessing HCC prognosis. Furthermore, there is a correlation between the expression of these risk model genes and tumor immunity.

Paederosidic acid protect bone mass in lipopolysaccharide-treated rats by reducing oxidative stress and inflammatory

Paederosidic acid (PA) has shown beneficial effects in anti-inflammatory studies, but it is unclear whether PA has positive impacts on bone loss induced by lipopolysaccharide (LPS). This study aims to investigate the influence of PA on bone loss in LPS-treated rats. The study assesses changes in the viability and osteogenic potential of MC3T3-E1 cells, as well as osteoclast differentiation in RAW264.7 cells in the presence of LPS using CCK-8, ALP staining, AR staining, and Tartrate-resistant acid phosphatase (TRAP) staining. In vitro experiments indicate that LPS-induced inhibition of osteoclasts (OC) and Superoxide Dismutase 2 (SOD2) correlates with heightened levels of inflammation and oxidative stress. Furthermore, PA has demonstrated the ability to alleviate oxidative stress and inflammation, enhance osteogenic differentiation, and suppress osteoclast differentiation. Animal experiments also show that PA significantly upregulates SOD2 expression while downregulating TNF-α expression (all, p < 0.05), leading to the restoration of impaired bone metabolism, improved bone strength, and increased bone mineral density (all, p < 0.05), compared to the control group. The collective experimental findings strongly suggest that PA can enhance osteogenic activity in the presence of LPS by reducing inflammation and oxidative stress, hindering osteoclast differentiation; hence mitigating bone loss in LPS-treated rat models.

Pharmacology and mechanisms of apigenin in preventing osteoporosis

Osteoporosis (OP) stands as the most prevalent systemic skeletal condition associated with aging. The current clinical management of OP predominantly depends on anti-resorptive and anabolic agents. Nevertheless, prolonged use of some of these medications has been observed to reduce efficacy and elevate adverse effects. Given the necessity for sustained or even lifelong treatment of OP, the identification of drugs that are not only effective but also safe and cost-efficient is of utmost significance. As disease treatment paradigms continue to evolve and recent advancements in OP research come to light, certain plant-derived compounds have emerged, presenting notable benefits in the management of OP. This review primarily explores the pharmacological properties of apigenin and elucidates its therapeutic mechanisms in the context of OP. The insights provided herein aspire to offer a foundation for the judicious use of apigenin in forthcoming research, particularly within the scope of OP.

Isoquercitrin Loaded PEGylated Long Circulating Liposomes Improve Bone Mass and Reduce Oxidative Stress After Osteoporosis

Osteoporosis has increasingly become a major public health concern because of its associated heightened risk of bone fragility and fractures. In order to avoid the adverse risk of hormone therapy, scientists have considered isoquercitrin (IQ) as a natural phytoestrogen to potentially prevent osteoporosis. However, IQ has poor solubility and bioavailability which culminates in rapid elimination of phytoestrogen. Herein, this study sought to solve limited applications of IQ by preparing IQ-loaded PEGylated long circulating liposomes (IQ-Lips) via thin-film hydration method. After appropriate characterization using zeta-potential, polydispersed index (PDI), particle size and entrapment efficiency (EE), IQ-Lips were applied to ovariectomized rat models to evaluate their effect on osteoporosis. The results showed that the prepared IQ-Lips exhibited smaller sized nanoparticles (125.35 ± 4.50 nm), excellent PDI (0.244 ± 0.001) and zeta-potential (-28.64 ± 0.71 mV) with stable property and higher EE (92.10 ± 0.32%). Importantly, administration of IQ-Lips through oral route increased aqueous solvability, bioavailability and circulation time of IQ. Moreover, the IQ-Lips could increase bone microstructural densities and bone mass, as well as reduce oxidative stress in ovariectomized rat models. Altogether, the IQ-Lips may serve as a novel avenue to potentially prolong the circulation of IQ in the body and improve the bioavailability of IQ for treatment of osteoporosis.

Fine particulate matter and osteoporosis: evidence, mechanisms, and emerging perspectives

Air pollution, particularly fine particulate matter with an aerodynamic diameter of ≤2.5 μm (PM2.5), has been recognized for its adverse effects on multiple organs beyond the lungs. Among these, the bone began to garner significant attention. This review covers epidemiological, animal, and cell studies on PM2.5 exposure and bone health as well as studies on PM2.5-induced diseases with skeletal complications. Emerging evidence from epidemiological studies indicates a positive association between PM2.5 exposure and the incidence of osteoporosis and fractures, along with a negative association with bone mineral density. Experimental studies have demonstrated that PM2.5 can disrupt the metabolic balance between osteoclasts and osteoblasts through inflammatory responses, oxidative stress, and endocrine disruption, thereby triggering bone loss and osteoporosis. Additionally, this review proposes a secondary mechanism by which PM2.5 may impair bone homeostasis via pathological alterations in other organs, offering new perspectives on the complex interactions between environmental pollutants and bone health. In conclusion, this contemporary review underscores the often-overlooked risk factors of PM2.5 in terms of its adverse effects on bone and elucidates the mechanisms of both primary and secondary toxicity. Further attention should be given to exploring the molecular mechanisms of PM2.5-induced bone impairment and developing effective intervention strategies.

Unraveling the Bone-Brain Axis: A New Frontier in Parkinson's Disease Research

Parkinson's disease (PD), as a widespread neurodegenerative disorder, significantly impacts patients' quality of life. Its primary symptoms include motor disturbances, tremor, muscle stiffness, and balance disorders. In recent years, with the advancement of research, the concept of the bone-brain axis has gradually become a focal point in the field of PD research. The bone-brain axis refers to the interactions and connections between the skeletal system and the central nervous system (CNS), playing a crucial role in the pathogenesis and pathological processes of PD. The purpose of this review is to comprehensively and deeply explore the bone-brain axis in PD, covering various aspects such as the complex relationship between bone metabolism and PD, the key roles of neurotransmitters and hormones in the bone-brain axis, the role of inflammation and immunity, microRNA (miRNA) functional regulation, and potential therapeutic strategies. Through a comprehensive analysis and in-depth discussion of numerous research findings, this review aims to provide a solid theoretical foundation for a deeper understanding of the pathogenesis of PD and to offer strong support for the development of new treatment methods.

Disentangling the Relationship Between Urinary Metal Exposure and Osteoporosis Risk Across a Broad Population: A Comprehensive Supervised and Unsupervised Analysis

Background: Limited evidence links urinary metal exposure to osteoporosis in broad populations, prompting this study to cover this knowledge gap using supervised and unsupervised approaches. Methods: This study included 15,923 participants from the National Health and Nutrition Examination Survey (NHANES) spanning from 1999 to 2020. Urinary concentrations of nine metals-barium (Ba), cadmium (Cd), cobalt (Co), cesium (Cs), molybdenum (Mo), lead (Pb), antimony (Sb), thallium (Tl), and tungsten (Tu)-were measured using inductively coupled plasma mass spectrometry (ICP-MS). Osteoporosis was assessed via dual-energy X-ray absorptiometry. A weighted quantile sum (WQS) regression analysis evaluated each metal's contribution to osteoporosis risk. Partitioning around medoids (PAM) clustering identified the high- and low-exposure groups, and their association with the risk and prognosis of osteoporosis was evaluated. Results: WQS regression identified Cd as a significant osteoporosis risk factor in the general population (odds ratio (OR) = 1.19, 95% confidence interval (CI): 1.08, 1.31, weight = 0.66). Pb notably affected those individuals aged 30-49 years and classified as Mexican American, while Sb impacted Black individuals. PAM clustering showed that the high-exposure group had a significantly higher risk of osteoporosis (OR = 1.74, 95% CI: 1.43, 2.12) and cumulative mortality risk. Conclusions: Urinary metals are associated with the risk and prognosis of osteoporosis.

Construction a novel osteoporosis model in immune-deficient mice with natural ageing

Osteoporosis (OP) predominantly affects elderly individuals. Stem cells show potential for treating OP. However, animal models with normal immune function can eliminate implanted human cells. This study utilized naturally aging NOD/SCID mice, which exhibit immunodeficiency, to create a human osteoporosis model. This approach helps to minimize the premature immune clearance of transplanted allogeneic or xenogeneic cells in preclinical studies, allowing for a more accurate replication of the clinical pharmacological and pharmacokinetic processes involved in stem cell interventions for osteoporosis. NOD/SCID mice were fed until 12, 32, and 43 weeks of age, respectively, and then euthanized. We harvested lumbar vertebra for Micro-Computed Tomography (Micro-CT) scanning and pathological examination. Additionally, we performed biomechanical testing of lumbar vertebra to assess the severity of osteoporosis. We utilized real-time RT-PCR to assess gene expression changes associated with bone metabolism, aging, inflammation, oxidative stress, and the Tgf-β1/Smad3 signaling pathway. In addition, the protein expression levels of P16, Tgf-β1 and Smad3 were detected using Western Blotting (WB). In comparison to 12-week-old mice, the 32-week-old and 43-week-old mice displayed significantly sparser and fractured trabeculae in their lumbar vertebra, lower bone mineral density (BMD), and changes in bone microstructural parameters (∗∗P < 0.01, ∗∗∗P < 0.001). Additionally, compared to 12-week-old mice, the 32-week-old and 43-week-old mice exhibited decreased expression of osteogenic genes (Alp, Opg, Sp7, Col1a1), increased expression of osteoclastic gene (Rankl), the number of TRAP-positive osteoclasts significantly increased in 32-week-old and 43-week-old mice compared to 12-week-old mice. The expression of genes related to aging and inflammatory (P16, Il-1β, Tnf-α) increases with advancing age (∗P < 0.05, ∗∗P < 0.01, ∗∗∗P < 0.001). The expression of oxidative stress-related genes (Sod1, Sod2, Foxo3, Nrf2), as well as Tgf-β1 and Smad3 decreased with age (∗P < 0.05, ∗∗P < 0.01, ∗∗∗P < 0.001). As age increases, the levels of P16 protein increase, Tgf-β1 and Smad3 proteins decrease. Our study successfully replicated osteoporosis models in NOD/SCID mice at both 32 and 43 weeks, with the latter exhibiting more severe osteoporosis. This condition seems to be driven by factors such as aging, inflammation, oxidative stress, and the Tgf-β1/Smad3 signaling pathway.

Association between advanced lung cancer inflammation index and osteoporosis in patients with type 2 diabetes mellitus: evidence from NHANES

Background

Previous studies have shown a significantly increased prevalence of osteoporosis (OP) in patients with type 2 diabetes mellitus (T2DM), which is closely associated with inflammation and nutrition. This study aimed to investigate the relationship between the advanced lung cancer inflammation index (ALI) and OP in patients with T2DM.

Methods

This cross-sectional analysis was conducted based on data from middle-aged and older adults aged 50 years and older with T2DM from the National Health and Nutrition Examination Survey (NHANES).Weighted multivariable logistic regression and linear regression were utilized to investigate the correlation between the ALI and OP with femur bone mineral density (BMD) in individuals with T2DM. Restricted cubic splines (RCS) were employed to assess potential nonlinear relationships, and receiver operating characteristic (ROC) curves were used to evaluate diagnostic accuracy.

Results

A total of 1596 patients with T2DM were included in this study, among whom 736 had OP. After adjusting for covariates, the multivariable logistic regression model showed that compared to participants in the fourth quartile of log2-transformed ALI, those in the first quartile had an increased prevalence of OP in T2DM (OR = 1.95, 95% CI=1.28-2.96, p < 0.01). The multivariable linear regression model indicated that a low log2-transformed ALI is associated with a low femur BMD.RCS demonstrated a linear dose-response relationship between the ALI index and OP in T2DM (p = 0.686), with the area under the ROC curve being 0.57 (95% CI: 0.54-0.60, p < 0.001), and the optimal cutoff value was 6.04.

Conclusion

Our findings indicate that low levels of ALI are independently associated with an increased prevalence of OP in middle-aged and older adults with T2DM in the United States. ALI may serve as a potential biomarker for assessing the prevalence of OP in middle-aged and older adults with T2DM.

The radical scavenging activity of 1-methyl-1,4-dihydronicotinamide: theoretical insights into the mechanism, kinetics and solvent effects

1,4-Dihydronicotinamide derivatives, including 1-methyl-1,4-dihydronicotinamide (MNAH), are derivatives of the active center of nicotinamide coenzyme (NADH) and are therefore potent radical scavengers. MNAH serves as a useful model of NADH that allows for modeling studies to address the activity of this important biomolecule. In this work, MNAH activity was evaluated against typical free radicals using quantum chemical calculations in physiological environments, with a secondary aim of comparing activity against two physiologically relevant radicals of markedly different stability, HO˙, and HOO˙, to establish which of these is a better model for assessing antioxidant capacity in physiological environments. The HO˙ + MNAH reaction exhibited diffusion-limited overall rate constants in all media, including the gas phase. The HOO˙ antiradical activity of MNAH was also good, with overall rate constants of 2.00 × 104 and 2.44 × 106 M-1 s-1, in lipid and aqueous media, respectively. The calculated rate constant in water (k overall(MNAH + HOO˙) = 3.84 × 105 M-1 s-1, pH = 5.6) is in good agreement with the experimental data (k exp(NADH + HOO˙) = (1.8 ± 0.2)×105 M-1 s-1). In terms of mechanism, the H-abstraction of the C4-H bond characterized the HOO˙ radical scavenging activity of MNAH, whereas HO˙ could react with MNAH at several sites and following either of SET (in polar media), RAF, and FHT reactions, which could be ascribed to the high reactivity of HO˙. For this reason the results suggest that activity against HOO˙ is a better basis for comparison of anti-radical potential. In the broader context, the HOO˙ scavanging activity of MNAH is better than that of reference antioxidants such as trans-resveratrol and ascorbic acid in the nonpolar environment, and Trolox in the aqueous physiological environment. Therefore, in the physiological environment, MNAH functions as a highly effective radical scavenger.

Chemical constituents and biological activities of endophytic fungi from Fagopyrum dibotrys

Background

Fagopyrum dibotrys is an important wild food and feed germplasm resource. It has high nutritional and medicinal value and is rich in natural products, including flavonoids, phenolic acids, coumarins, and alkaloids. Endophytic fungi in F. dibotrys have emerged as valuable sources of natural products. However, studies on the biological activity and chemical composition of these endophytic fungi remain limited.

Methods

In this paper, a new method to obtain natural active ingredients by fermentation of endophytic fungi from medicinal plants was proposed. Then the antioxidant and pathogenic activities of the endophytic fungi extracts were determined in vitro. In addition, secondary metabolites produced by endophytic fungi with medicinal activity were analyzed by high performance liquid chromatography-tandem mass spectrometry (LC-MS).

Results

Among the 95 endophytic fungal strains in F. dibotrys, four strains with high phenol yields were selected by reaction: Alternaria alstroemeriae (J2), Fusarium oxysporum (J15), Colletotrichum karsti (J74), and Colletotrichum boninense (J61). Compared with those of various extracts, the ethyl acetate fractions of A. alstroemeriae (J2), F. oxysporum (J15), and C. boninense (J61) exhibited superior antioxidant and antibacterial properties. The results indicated that the fungal extract was an excellent natural antioxidant and might be a potential antibacterial agent. The DPPH free radical clearance of A. alstroemeriae was 94.96 ± 0.004%. These findings indicated that A. alstroemeriae had strong antioxidant activity. In addition, the extract of A. alstroemeriae had good antibacterial activity against Escherichia coli and Staphylococcus aureus, with MICs of 0.5 and 0.05 mg/mL, respectively. The chemical constituents of the ethyl acetate extract from A. alstroemeriae were further analyzed by liquid chromatography-mass spectrometry (LC-MS). We noted that A. alstroemeriae can create a variety of medicinal substances that have high value in medicine, such as caffeic acid (884.75 ng/mL), 3-phenyllactic acid (240.72 ng/mL) and norlichexanthone (74.36 ng/mL).

Discussion

In summary, many valuable active substances and medicinal substances can be obtained through the study of endophytic fungi of F. dibotrys.

Melatonin prevents bone loss in osteoporotic rats with valproic acid treatment by anti-inflammatory and anti-oxidative stress

Melatonin (MEL) has shown positive effects in anti-inflammatory and anti-oxidative stress research. This study investigates whether MEL can positively impact bone loss induced by valproic acid (VPA) in rats. The study examines changes in MC3T3-E1 cell viability and osteogenic potential, along with osteoclast differentiation in RAW264.7 cells in the presence of VPA using CCK-8, ALP staining, AR staining, and TRAP staining. In vitro experiments reveal that VPA-induced inhibition of osteogenic differentiation and promotion of osteoclastic differentiation are linked to increased inflammation and oxidative stress. Furthermore, MEL has demonstrated the ability to reduce oxidative stress and inflammation, boost osteogenic differentiation, and inhibit osteoclast differentiation. Animal experiments confirm that MEL significantly increases SOD2 expression and decreases TNF-α expression, leading to the restoration of impaired bone metabolism, enhanced bone strength, and higher bone mineral density. The combined experimental results strongly suggest that MEL can enhance osteogenic activity in the presence of VPA by reducing inflammation and oxidative stress, impeding osteoclast differentiation, and alleviating bone loss in VPA-treated rat models.

Gut microbiota and metabolic profile changes unveil the deterioration of alveolar bone inflammatory resorption with aging induced by D-galactose

The global aging population has led to a rise in age-related health issues, such as malnutrition, metabolic disorders, and even immune decline. Among these concerns, periodontitis holds particular significance for the well-being of the elderly. This study aimed to investigate the impact of aging on inflammatory resorption of alveolar bone in mice with periodontitis, with a specific focus on alterations in the intestinal microenvironment. To achieve this, we established a D-galactose (D-gal)-induced aging mouse model with periodontitis and employed histopathological staining, oxidative stress, and inflammatory factors analyses to assess the severity of periodontitis and the health status. Additionally, the 16S rRNA sequencing and untargeted metabolomics analysis were employed to investigate alterations in the intestinal microbiota and metabolites. Our results showed that D-gal-induced aging mice with periodontitis experienced more pronounced alveolar bone inflammatory resorption and disruptions in the gut barrier, accompanied by an overall decline in physical condition. The microbial composition and structure of aged mice also underwent significant modifications, with a decreased Firmicutes/Bacteroidetes (F/B) ratio. Furthermore, metabolomics analysis demonstrated that D-gal-induced aging primarily influenced lipids and lipid-like molecules metabolism, and enrichment observed in the rheumatoid arthritis and histidine metabolism pathways. These findings provide further evidence that the aging process exacerbates age-related alveolar bone loss (ABL) through disturbances in intestinal homeostasis.