Antiosteoporotic activity and constituents of Podocarpium podocarpum

Hemoglobin is associated with BMDs and risk of the 10-year probability of fractures in patients with type 2 diabetes mellitus

Purpose

This study aimed to investigate the associations between hemoglobin (HGB) levels and bone mineral density (BMD) and fracture risk in type 2 diabetes mellitus(T2DM) population of different ages.

Method

This cross-sectional study included 641 patients with T2DM (57.9% males). BMD of the femoral neck (FN), total hip (TH), and lumbar spine (LS) were measured using dual-energy X-ray absorptiometry. The 10-year probability of fracture was assessed using a fracture risk assessment tool (FRAX). HGB and other biochemical indices were measured in a certified laboratory at our hospital. Statistical analysis was performed using SPSS 26.0 and R language (R version 4.1.0). Generalized additive models (GAMs) were used to identify the associations between HGB and BMD and fracture risk.

Results

Patients with osteoporosis have lower HGB levels than the non-osteoporotic population and lower FN BMD in patients with anemia than in the non-anemic population. In patients with T2DM, there was sex- and age-related variability in the correlation between HGB levels and BMDs and fracture risk. In older men, HGB level was an independent determinant of BMD and was positively correlated with FN and TH BMD. In non-older women, HGB level was an independent determinant of BMD and fracture risk, positively associated with BMDs and negatively associated with 10-year probability of fracture risk. GAMs revealed a positive linear association between HGB level and BMDs in non-older female patients but not in older male patients.

Conclusion

Our study provides a new perspective on the association of HGB level and BMDs with fracture risk. Relatively high HGB levels are a protective factor for bone quality in patients with T2DM. However, the bone-protective effect of HGB is influenced by age and sex and persists only in older men and non-older women with T2DM.

Effect of Menaquinone-4 on Receptor Activator of Nuclear Factor κB Ligand-Induced Osteoclast Differentiation and Ovariectomy-Induced Bone Loss

Osteoporosis is a progressive metabolic disease characterized by decreased bone mineral density and increased fracture risk. Previous studies have shown that higher intake of vitamin K (VK) correlates with a reduced risk of osteoporosis. However, the effect of menaquinone-4 (MK-4), a specific form of VK, still remains obscure. Therefore, in this study, we investigated the effects of MK-4 on osteoclast differentiation by differentiating RAW 264.7 cells into osteoclasts with the help of receptor activator of nuclear factor-kappa B ligand (RANKL), assessed the mRNA expression of osteoclast-specific genes, and studied the effects of MK-4 in vivo in ovariectomized mice, a postmenopausal osteoporosis murine model. MK-4 inhibited osteoclast differentiation, decreased the mRNA expression of nuclear factor of activated T cells c1 (NFATc1), osteoclast-associated receptor (OSCAR), and cathepsin K (CTSK), and inhibited bone loss in ovariectomized mice. The findings strongly suggest that MK-4 is a therapeutic alternative for postmenopausal osteoporosis.

Identification and Quantification of Key Phytochemicals, Phytohormones, and Antioxidant Properties in Coccinia grandis during Fruit Ripening

Coccinia grandis contains secondary metabolites, such as flavonoids, phenolic acids, terpenoids, alkaloids, sterols, and glycosides, which are known to have in vitro antioxidant, antidiabetic, anti-inflammatory, and antidyslipidemic activities. C. grandis fruits change dramatically during ripening, and the differences in the phytochemicals contribute to various uses. This study reports the phytochemical compounds and antioxidant activities during ripening of C. grandis for the first time. Characterizations were conducted on the physiologically active substances in C. grandis fruits at three ripening stages, and a total of 25 peaks were identified. Key phytochemicals in the ripening stages of C. grandis were identified, and the major substances that contributed to antioxidant properties were selected and quantitatively analyzed. Although the concentration of tiliroside increased during aging, hydroxycinnamic acid (chlorogenic and p-coumaric acids), flavonols (rutin), and triterpenes (cucurbitacins B and D) with antioxidant effects decreased. Therefore, phenolic compounds and cucurbitacins dominate immature C. grandis quantitatively. Regarding phytohormones, the gibberellin A4 content decreased as the fruits matured, but indoleacetic acid and salicylic acid increased with fruit maturity. The antioxidant capacities determined by DPPH and ABTS consistently decreased with increasing maturity. Accordingly, the extracts of immature C. grandis fruits have high levels of bioactive compounds and can be used to develop food additives and health supplements.

The Brown Algae Ishige sinicola Extract Ameliorates Ovariectomy-Induced Bone Loss in Rats and Suppresses Osteoclastogenesis through Downregulation of NFATc1/c-Fos

Osteoporosis is characterized by reduction in bone mass and microarchitectural deterioration of the bone, which causes bone fragility and fracture susceptibility. Ishige sinicola, a brown alga, reportedly affects osteoblast differentiation. However, its protective effect on estrogen deficiency-induced bone loss has not been elucidated. This study aimed to investigate the effect of I. sinicola extract (ISE) on ovariectomy (OVX)-induced bone loss in vivo and osteoclastogenesis in vitro. Female Sprague-Dawley rats were randomly assigned to the sham-operated (SHAM) group and four OVX subgroups: SHAM, OVX, ISE20 (20 mg/kg), ISE200 (200 mg/kg), and estradiol (10 μg/kg). After 6 weeks of treatment, the bone mineral density (BMD), femur indices, and serum biomarker levels were measured. Furthermore, the effects of ISE on osteoclastogenesis and the expression of osteoclast-specific markers were measured. ISE administration improved the trabecular bone structure, bone biomechanical properties, BMD, and bone mineralization degree. In addition, the levels of serum bone turnover markers were decreased in the ISE group compared with those in the OVX group. Moreover, ISE inhibited osteoclast formation by downregulating NFATc1, TRAP, c-Src, c-Fos, and cathepsin K without any cytotoxic effects on RANKL-induced osteoclast formation. Therefore, we suggest that ISE has therapeutic potential in postmenopausal osteoporosis.

Multitarget-Based Virtual Screening for Identification of Herbal Substances toward Potential Osteoclastic Targets

Osteoporosis is a complex bone disease indicating porous bone with low bone mass density and fragility. Cathepsin K, V-ATPase, and αVβ3 integrin are exhibited as novel targets for osteoporosis treatment. Our preliminary study uses a state-of-the-art method, including target-based virtual screening and clustering methods to determine promising candidates with multitarget properties. Phytochemicals with osteoprotective properties from the literature are used to elucidate the molecular interactions toward three targets. The binding scores of compounds are normalized and rescored. The K-means and hierarchical clustering methods are applied to filter and define the promising compounds, and the silhouette analysis is supposed to validate the clustering method. We explore 108 herbal compounds by virtual screening and the cluster approach, and find that rutin, sagittatoside A, icariin, and kaempferitrin showed strong binding affinities against Cathepsin K, V-ATPase, and αVβ3 integrin. Dockings of candidates toward three targets also provide the protein-ligand interactions and crucial amino acids for binding. Our study provides a straightforward and less time-consuming approach to exploring the new multitarget candidates for further investigations, using a combination of in silico methods.

The phytoestrogen glabrene prevents osteoporosis in ovariectomized rats through upregulation of the canonical Wnt/β-catenin signaling pathway

This study systematically investigated the effects of phytoestrogen glabrene on postmenopausal osteoporosis in an ovariectomy (OVX) rat model. Glabrene administration (25, 50, and 100 mg/kg) for 13 weeks can significantly slow down the body weight gain and slightly increase the uterus weight of OVX rats. The increased levels of U-Ca, U-P levels, urine DPD/creatinine, serum ALP, OCN, triglycerides, and total cholesterol induced by OVX were dramatically inhibited in rats, whereas no difference occurred for S-Ca and S-P in all groups. Furthermore, glabrene can enhance bone mineral density of the right femur, fourth-lumbar vertebra and tibia and improve biomechanical parameters, such as femoral neck loading force, three-point bending of the tibia, and vertebral compression in OVX rats. Moreover, glabrene greatly suppressed the expression of TRAP protein but increased OPG and BGP protein expression in tibia tissue of OVX rats. In addition, OVX-induced reduction of Lrp-5, β-catenin, Runx2, and Osx protein expression was all restored by glabrene treatment. The present study indicated that glabrene might be a potential alternative medicine for the prevention and treatment of postmenopausal osteoporosis via activation of the Wnt/β-catenin signaling pathway.

Anti-Osteoporotic Activity of an Edible Traditional Chinese Medicine Cistanche deserticola on Bone Metabolism of Ovariectomized Rats Through RANKL/RANK/TRAF6-Mediated Signaling Pathways

Given the limitations of existing therapeutic agents for treatment of postmenopausal osteoporosis, there still remains a need for more options with both efficacy and less adverse effects. Cistanche deserticola Y. C. Ma is known as a popular tonic herb traditionally used to treatment deficiency of kidney energy including muscle weakness in minority area of Asian counties. Based on the theory of “kidney dominate bone,” an ovariectomized (OVX) rat model of postmenopausal osteoporosis was used to evaluate the therapeutic effect of C. deserticola extract (CDE) on bone loss. Forty eight female Sprague-Dawley rats, aged about 12 weeks, were randomly assigned into six groups including sham group orally administrated with 0.5% carboxymethyl cellulose sodium (CMC-Na) (sham), positive group treated with 1 mg/kg of estradiol valerate (EV), low, moderate, and high dosage groups orally administrated with 200, 400, and 800 mg/kg/day of CDE, respectively. After 3 months of continuous intervention, CDE exhibited significant anti-osteoporotic activity evidenced by the enhanced total bone mineral density, ameliorated bone microarchitecture; increased alkaline phosphatase activity; decreased deoxypyridinoline, cathepsin K, tartrate-resistant acid phosphatase, and malondialdehyde levels; whereas the body, uterus, and vagina weights in OVX rats were not influenced by CDE intervention. In addition, a seemed contradictory phenomenon on levels of calcium and phosphorus between OVX and sham rats were observed and elucidated. Mechanistically, CDE significantly down-regulated the levels of TRAF6, RANKL, RANK, NF-κB, IKKβ, NFAT2, and up-regulated the phosphatidylinositol 3-kinase (PI3K), AKT, osteoprotegerin, and c-Fos expressions, which implied CDE could suppress RANKL/RANK-induced activation of downstream NF-κB and PI3K/AKT pathways, and ultimately, preventing activity of the key osteoclastogenic proteins NFAT2 and c-Fos. All of the data suggested CDE possessed potential anti-osteoporotic activity and this effect was, at least in part, involved in modulation of RANKL/RANK/TRAF6-mediated NF-κB and PI3K/AKT signaling as well as c-Fos and NFAT2 levels. Therefore, CDE may represent a useful promising remedy candidate for treatment of postmenopausal osteoporosis.

Beneficial Effects of Total Phenylethanoid Glycoside Fraction Isolated from Cistanche deserticola on Bone Microstructure in Ovariectomized Rats

The present study was designed to estimate the antiosteoporotic activity of total phenylethanoid glycoside fraction isolated from C. deserticola (CDP) on rats induced by ovariectomy (OVX) as well as the related mechanisms. After 3 months of oral administration, the decreased bone mineral density, serum Ca, and P in OVX rats were recovered and the deteriorated trabecular bone microarchitecture was partly improved by CDP (60, 120, and 240 mg/kg) intervention, the activities of bone resorption markers were downregulated, and the bioactive of the bone formation index was upregulated; meanwhile, the content of MDA was declined, and GSH was increased by CDP treatment. Compositionally, 8 phenylethanoid glycoside compounds were identified in CDP, with the total contents quantified as 50.3% by using the HPLC method. Mechanistically, CDP declined the levels of TRAF6, RANKL, and RANK, thus suppressing RANKL/RANK/TRAF6-induced activation of downstream NF-κB and PI3K/AKT signaling pathways and ultimately preventing activities of the key osteoclastogenic proteins of NFAT2 and c-Fos. All of the above data implied that CDP exhibited beneficial effects on bone microstructure in ovariectomized rats, and these effects may be related to the NF-κB and PI3K/AKT signaling pathways which were triggered by the binding of RANKL, RANK, and TRAF6.

Effect of Black Tea Extract and Thearubigins on Osteoporosis in Rats and Osteoclast Formation in vitro

Background: Osteoporosis is a major health problem that is closely related to substantial morbidity, mortality and decline in life quality for the aging population. Although previous studies and epidemiological evidence have demonstrated an association between black tea consumption and the prevention of bone loss, the underlying mechanism remains unclear. So, the effect of black tea extract (BTE) and thearubigins (TRs) on osteoporosis in rats and osteoclast formation in vitro were investigated.

Methods:In vivo, ovariectomized (OVX) rats were used to establish osteoporosis models. To validate the model and study the effects of BTE and TRs on osteoporosis, the female Wistar rats were divided into a sham-operated group and five OVX groups including model, Xian-Ling-Gu-Bao (XLGB) (as a positive control), BTE, TRs low-dose, and TRs high-dose group. The rats in the four treatment groups were given the corresponding test sample for 12 weeks. Then, the body weight, femur indices, and serum biomarkers were examined and analyzed. In vitro, RAW264.7 murine macrophages were used as model of osteoclast formation. The effects of BTE and TRs on osteoclasts formation and the specific genes and protein levels of osteoclasts were determined.

Results: Although there was no significant effect on the OVX-induced body weight gain by BTE or TRs, the levels of maximum bending force, cortical bone thickness and biomarker of bone resorption (acid phosphatase) can be significantly ameliorated by BTE or TRs in OVX rats. Furthermore, both of BTE and TRs can inhibit the osteoclastogenesis and diminish the expression levels of the related genes and proteins.

Syringin prevents bone loss in ovariectomized mice via TRAF6 mediated inhibition of NF-κB and stimulation of PI3K/AKT

BACKGROUND

Syringin, also called eleutheroside B, is a main bioactive phenolic glycoside in Acanthopanax senticosus (Rupr. et Maxim.) Harms. Based on the "kidney dominates bone" theory of TCM, A. senticosus can strengthen bone and Syringin may be one of the responsibilities.

PURPOSE

The objectives of this study were to estimate the osteoporotic activity of Syringin and reveal the possible molecular mechanisms in vivo.

METHODS

Sixty female ICR mice were randomly assigned into sham operated group (SHAM, treated with vehicle) and five ovariectomized subgroups (n = 10 each), treated with vehicle as OVX group, estradiol valerate (EV, 1 mg/kg/day) as positive group, and Syringin (10, 20 and 40 mg/kg/day) as low, moderate and high dosage groups. The therapeutic effect of Syringin against osteoporosis was systematically analyzed by determining the bone mineral density (BMD), bone biomechanical properties, bone microarchitecture and serum biochemical parameters, and the molecular mechanism was also evaluated.

RESULTS

After three months of orally administrated intervention, Syringin (10, 20 and 40 mg/kg/day) significantly improved the BMD, bone maximum load and trabecular bone microarchitecture in ovariectomized mice, evidenced by the increased bone mineral content, tissue mineral content, tissue mineral density, trabecular thickness and trabecular number, as well as the decreased trabecular separation in OVX mice. Meanwhile, the activities of tartrate-resistant acid phosphatase, deoxypyridinoline and cathepsin K in OVX mice were also inhibited by Syringin, while the increased body weight and decreased uterus weight seemed not influenced by Syringin administration. Concerning the underlying molecular mechanisms, Syringin significantly downregulated the expression of tumor-necrosis factor receptor-associated factor 6 (TRAF6), nuclear factor kappa B (NF-κB) and receptor activator of nuclear factor kappa B ligand (RANKL) proteins levels, upregulated the expression of osteoprotegerin (OPG), phosphoinositide 3-kinase (PI3K) and protein kinase B (AKT) levels, suggesting that Syringin prevented bone lost by TRAF6-mediated inhibition of NF-κB and stimulation of PI3K/AKT, and subsequently increasing the OPG/RANKL ratio and inhibiting the osteoclastogenesis, finally promoting bone formation.

CONCLUSIONS

All of the data implied Syringin possessed the potent anti-osteoporosis activity on ovariectomized mice, and the underlying molecular mechanism may be related to the NF-κB and PI3K/AKT signaling pathways.

Dendrobium officinale Orchid Extract Prevents Ovariectomy-Induced Osteoporosis in Vivo and Inhibits RANKL-Induced Osteoclast Differentiation in Vitro

Background:Dendrobium officinale, a traditional Chinese medical herb with high value that is widely used in Asia, possesses many positive effects on human health, including anti-chronic inflammation, anti-obesity, and immune modulation properties; however, whether D. officinale has inhibitory effects on postmenopausal osteoporosis remains unknown. Objective: We investigated the effects of D. officinale extract (DOE) on ovariectomy-induced bone loss in vivo and on osteoclastogenesis in vitro. Methods:In vivo, female rats were divided into a sham-operated (sham) group and five ovariectomized (OVX) subgroups: OVX with vehicle (OVX), OVX with Xian-Ling-Gu-Bao capsule (240 mg/kg body weight/day), and OVX with low-, medium-, and high-dose DOE (150, 300, and 600 mg/kg body weight/day, respectively). Animals in each group were administered their corresponding treatments for 13 weeks. Body weight, serum biochemical parameters, uterine and femoral physical parameters, bone mineral density (BMD), bone biomechanical properties, and bone microarchitecture were obtained. In vitro, the effects of DOE on osteoclastogenesis were examined using RAW264.7 cells. The effects of DOE on osteoclastogenesis and the expression of osteoclast-specific marker genes and proteins were determined. Results: DOE effectively ameliorated serum biochemical parameters, especially alleviated estradiol (E2) deficiency and maintained calcium and phosphorus homeostasis. DOE improved uterine and femoral physical parameters. In addition, DOE improved femoral BMD and biomechanical properties. DOE significantly ameliorated bone microarchitecture. Moreover, DOE inhibited osteoclastogenesis independent of its cytoxicity and suppressed the expression of osteoclast-specific marker genes and proteins. Conclusion: DOE can effectively prevent ovariectomy-induced bone loss in vivo and inhibit osteoclastogenesis in vitro.

Therapeutic Effect of Cistanoside A on Bone Metabolism of Ovariectomized Mice

Cistanoside A (Cis A), an active phenylethanoid glycoside isolated from Cistanche deserticola Y. C. Ma, has received our attention because of its possible role in the treatment of osteoporosis. In the present study, we evaluated the effects of Cis A on an ovariectomized (OVX) mice model and investigated its underlying molecular mechanisms of action. After 12 weeks of orally-administrated intervention, Cis A (20, 40 and 80 mg/kg body weight/day) exhibited significant antiosteoporotic effects on OVX mice, evidenced by enhanced bone strength, bone mineral density and improved trabecular bone microarchitecture. Meanwhile, the activities of bone resorption markers, including tartrate-resistant acid phosphatase (TRAP), deoxypyridinoline (DPD) and cathepsin K, were decreased, and the bioactivity of bone formation marker alkaline phosphatase (ALP) was increased. Mechanistically, Cis A inhibited the expression of TNF-receptor associated factor 6 (TRAF6), an upstream molecule that is shared by both nuclear factor kappa-light chain enhancer of activated B cells (NF-κB) and phosphatidylinositol 3-kinase (PI3K)/Akt pathways and subsequently suppressed the levels of receptor activators of nuclear factor kappaB ligand (RANKL), downregulated the expression of NF-κB and upregulated osteoprotegerin (OPG), PI3K and Akt, which means Cis A possessed antiosteoporotic activity in ovariectomized mice via TRAF6-mediated NF-kappaB inactivation and PI3K/Akt activation. Put together, we present novel findings that Cis A, by downregulating TRAF6, coordinates the inhibition of NF-κB and stimulation of PI3K/Akt pathways to promote bone formation and prevent bone resorption. These data demonstrated the potential of Cis A as a promising agent for the treatment of osteoporosis disease.

Natural Products from Chinese Medicines with Potential Benefits to Bone Health

Osteoporosis is a progressive, systemic bone disorder characterized by loss of bone mass and microstructure, leading to reduced bone strength and increased risk of fracture. It is often associated with reduced quality of life and other medical complications. The disease is common in the aging population, particularly among postmenopausal women and patients who receive long-term steroidal therapy. Given the rapid growth of the aging population, increasing life expectancy, the prevalence of bone loss, and financial burden to the healthcare system and individuals, demand for new therapeutic agents and nutritional supplements for the management and promotion of bone health is pressing. With the advent of global interest in complementary and alternative medicine and natural products, Chinese medicine serves as a viable source to offer benefits for the improvement and maintenance of bone health. This review summarizes the scientific information obtained from recent literatures on the chemical ingredients of Chinese medicinal plants that have been reported to possess osteoprotective and related properties in cell-based and/or animal models. Some of these natural products (or their derivatives) may become promising leads for development into dietary supplements or therapeutic drugs.

Kaempferitrin prevents bone lost in ovariectomized rats

BACKGROUND

Podocarpium podocarpum (DC.), an edible and medicinal plant popularly used for the treatment of bruises and fracture in Chinese folk medicine, has been proved to possess significant antiosteoporotic effect in our latest research.

PURPOSE

Our study aimed to investigate the in vitro and in vivo antiosteoporotic effect of kaempfertrin (KN), a principal flavonoid in P. podocarpum obtained through bio-guided isolation.

METHODS

An ovariectomized (OVX) rat model of osteoporosis as well as in vitro osteoblast and osteoclast cell lines were employed to evaluate the antiosteoporotic potency of KN.

RESULTS

KN significantly improved the bone mass and microarchitecture in OVX rats, with little estrogen-like side effect compared with estradiol valerate. KN also exhibited stimulatory effect on osteoblastic cells and inhibitory action on osteoclastic cells, which down-regulated the phosphorylation level of I-κB.

CONCLUSION

KN possessed significant antiosteoporotic activity. Combined with its limited estrogen-like side effect, KN can be regarded as an idealistic antiosteoporotic candidate for human osteoporosis diseases.