Potential antiosteoporotic agents from plants: a comprehensive review

Chlorogenic Acid-Cucurbit[n]uril Nanocomplex Delivery System: Synthesis and Evaluations for Potential Applications in Osteoporosis Medication

Purpose

Based on nanomedicine strategies, this study employed cucurbit[7]uril (Q[7]) as the macromolecular carrier to synthesize nanocomplex drug delivery system for chlorogenic acid (CGA). The nanocomplex drug delivery system is intended to overcome the unsatisfactory biocompatibility and bioavailability of CGA and realizing its potential role in long-term osteoporosis (OP) medication.

Methods

The nanocomplex was synthesized by the reflux stirring method. The chemical structure of the nanocomplex was characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction analysis (XRD), UV-visible spectrophotometry (UV-vis), zeta potential analysis and transmission electronic microscope (TEM). The Cell Counting Kit-8 (CCK-8) assay, Live/Dead staining assay, and cytoskeleton staining were conducted to testify the biocompatibility of the nanocomplex. The release assay, Ferric Reducing Ability of Plasma (Frap) assay and Reactive oxygen species (ROS) staining were implemented to evaluate the release profile of CGA as well as its remaining antioxidative levels.

Results

CGA and Q[7] formed hydrogen bonding through an exclusion interaction, with the binding ratio more than 1:1. The nanocomplex had a crystalline and spherical-like structure and improved thermal stability. The nanocomplex demonstrated better biocompatibility than free CGA. The release profile of CGA from the nanocomplex was much steadier, and 70% of CGA was released in 5 days. The CGA released from the nanocomplex maintained its antioxidative properties at high levels and effectively eliminated the accumulated ROS in MC3T3-E1 cells under oxidative stress.

Conclusion

Q[7] has been demonstrated to be an ideal nanocarrier for CGA and the nanocomplex delivery system holds the potential for the long-term medication strategy of OP.

Sea buckthorn and its flavonoids isorhamnetin, quercetin, and kaempferol favorably influence bone and breast tissue health

Bone tissue and breast tissue are interrelated, as demonstrated by breast microcalcifications, breast cancer bone metastases, bone morphogenetic proteins, and Wnt signaling. In addition, osteoblasts and osteoclasts represent an important switch of tumor cell dormancy during bone metastasis. Damage to both types of tissues mentioned above is highly prevalent, especially in postmenopausal women, and manifests itself in osteoporosis and breast cancer. Sea buckthorn (Elaeagnus rhamnoides L.), a botanical drug with high antioxidant, antitumor, anti-inflammatory, immunomodulatory, and regenerative properties, has great therapeutic potential due to the unique composition of its bioactive metabolites. This review aimed to summarize the current knowledge from in vitro and in vivo studies on the effect of sea buckthorn, as well as its most widespread flavonoids isorhamnetin, quercetin, and kaempferol, on bone and breast tissue health. In vitro studies have revealed the beneficial impacts of sea buckthorn and aforementioned flavonoids on both bone health (bone remodeling, mineralization, and oxidative stress) and breast tissue health (cancer cell proliferation, apoptosis, tumor growth, and metastatic behavior). In vivo studies have documented their protective effects against disturbed bone microarchitecture and reduced bone strength in animal models of osteoporosis, as well as against tumor expansion and metastatic properties in animal xenograft models. In any case, further research and clinical trials are needed to carefully evaluate the potential therapeutic benefits of sea buckthorn and its flavonoids. Based on the available information, however, it can be concluded that these bioactive metabolites favorably affect both bone and breast tissue health.

Heraclenin promotes the osteogenic differentiation of bone marrow stromal cells by activating the RhoA/ROCK pathway

BACKGROUND

Osteoporosis is a devastating skeletal disease, the pathogenesis of which is related to abnormal bone metabolism, featured by the imbalance between osteoblastic bone formation and osteoclastic bone resorption. Stem cell-based therapies have been demonstrated to improve osteoporosis treatment. Previously, the linear furanocoumarin heraclenin was reported to enhance osteoblast differentiation and mineralization in mouse mesenchymal stem cells (MSCs), suggesting its potential for osteogenic differentiation and bone regeneration. Our study was designed to confirm the promotive role of heraclenin on osteogenic differentiation of human bone MSCs (BMSCs) and explore the underlying mechanisms.

METHODS

Human BMSCs were treated for 24, 48, and 72h with heraclenin (5, 10, 20, 40, and 80 μM), and cell viability was determined by Cell Counting Kit-8 (CCK-8) assay. To further evaluate the cytotoxicity of heraclenin, cell suspension obtained from BMSCs treated with heraclenin (5, 10, and 20 μM) for 72h was subjected to a MUSE™ cell analyzer for cell viability and count assay. BMSCs were incubated in osteogenic induction medium for 7 days. Then, osteogenic differentiation and mineralization of BMSCs were assessed through alkaline phosphatase (ALP) and Alizarin Red S staining. The expression of osteogenesis markers including ALP, osteocalcin (OCN), osterix (OSX), and runt-related transcription factor 2 (RUNX2) was detected via reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blotting. The effects of heraclenin on the RhoA/ROCK pathway were estimated through western blotting. Y-27632, the ROCK inhibitor, was used to confirm the role of the RhoA/ROCK pathway in heraclenin-mediated osteogenic differentiation of BMSCs.

RESULTS

Heraclenin (5-80 μM) was non-toxic on human BMSCs. Heraclenin treatment (5-20 μM) dose-dependently enhanced ALP activity and calcium deposition. Furthermore, heraclenin promoted ALP, OCN, OSX, and RUNX2 mRNA and protein expression. Mechanically, heraclenin treatment increased RhoA and ROCK1 mRNA expression, stimulated the translocation of ROCK from the cytosolic to the membrane fraction, and elevated the protein levels of phosphorylated cofilin (p-cofilin) and active RhoA. Additionally, treatment with Y-27632 overturned the promotion of heraclenin on ALP activity, calcium deposition, the expression of osteogenesis markers, and the RhoA/ROCK signaling pathway.

CONCLUSION

Heraclenin facilitates the osteogenic differentiation of human BMSCs through the activation of the RhoA/ROCK pathway.

Medicinal Plants for the Treatment of Neuropathic Pain: A Review of Randomized Controlled Trials

Neuropathic pain is a disabling condition caused by various diseases and can profoundly impact the quality of life. Unfortunately, current treatments often do not produce complete amelioration and can be associated with potential side effects. Recently, herbal drugs have garnered more attention as an alternative or a complementary treatment. In this article, we summarized the results of randomized clinical trials to evaluate the effects of various phytomedicines on neuropathic pain. In addition, we discussed their main bioactive components and potential mechanisms of action to provide a better view of the application of herbal drugs for treating neuropathic pain.

Optimization Conditions of Ultrasound-Assisted Extraction for Phenolic Compounds and Antioxidant Activity from Rubus alceifolius Poir Leaves

Rubus alceifolius Poir (R.A. Poir) leaves are rich in phenolic compounds, offering many health benefits due to their incredible antioxidant potential. In this study, conditions for the ultrasound-assisted extraction (UAE) of phenolic compounds and antioxidant activity from R.A. Poir leaves were optimized using response surface methodology (RSM). This methodology assessed the effects of ultrasound power (X1: 100-500 W), extraction temperature (X2: 30-60°C), and extraction time (X3: 5-55 min). The optimized UAE conditions were then compared with conventional extraction methods (Soxhlet extraction: SE and maceration extraction: ME) for extracting total phenolics. A phenolic profile using GC-MS and antioxidant activity (ABTS) was also compared. According to the RSM, the best conditions for UAE to extract the highest total polyphenol content and ABTS radical scavenging activity were 320 W ultrasound power, 40°C extraction temperature, and 35.5 min sonication duration. Under these optimal conditions, the TPC and antioxidant activity reached 16.68 mg GAE/g dm and 21.9 mg TE/g, respectively, closely aligning with the predicted values. The UAE extraction technique proved to be more efficient in extracting phenolics and antioxidant capacity (ABTS (2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid)) radical scavenging activity, and enzyme inhibition) compared to the conventional extraction methods (SE and ME). A GC-MS analysis identified 12 components, including 5 phenolics and 3 flavonoids, which likely contribute to the antioxidant activity. Consequently, the UAE method improved extraction efficiency within a shorter time frame, suggesting that UAE is a promising, efficient, and ecofriendly technology for extracting bioactive compounds from R.A. Poir leaves.

Bisphosphonate-incorporated coatings for orthopedic implants functionalization

Bisphosphonates (BPs), the stable analogs of pyrophosphate, are well-known inhibitors of osteoclastogenesis to prevent osteoporotic bone loss and improve implant osseointegration in patients suffering from osteoporosis. Compared to systemic administration, BPs-incorporated coatings enable the direct delivery of BPs to the local area, which will precisely enhance osseointegration and bone repair without the systemic side effects. However, an elaborate and comprehensive review of BP coatings of implants is lacking. Herein, the cellular level (e.g., osteoclasts, osteocytes, osteoblasts, osteoclast precursors, and bone mesenchymal stem cells) and molecular biological regulatory mechanism of BPs in regulating bone homeostasis are overviewed systematically. Moreover, the currently available methods (e.g., chemical reaction, porous carriers, and organic material films) of BP coatings construction are outlined and summarized in detail. As one of the key directions, the latest advances of BP-coated implants to enhance bone repair and osseointegration in basic experiments and clinical trials are presented and critically evaluated. Finally, the challenges and prospects of BP coatings are also purposed, and it will open a new chapter in clinical translation for BP-coated implants.

Achievements in Mesoporous Bioactive Glasses for Biomedical Applications

Nowadays, mesoporous bioactive glasses (MBGs) are envisaged as promising candidates in the field of bioceramics for bone tissue regeneration. This is ascribed to their singular chemical composition, structural and textural properties and easy-to-functionalize surface, giving rise to accelerated bioactive responses and capacity for local drug delivery. Since their discovery at the beginning of the 21st century, pioneering research efforts focused on the design and fabrication of MBGs with optimal compositional, textural and structural properties to elicit superior bioactive behavior. The current trends conceive MBGs as multitherapy systems for the treatment of bone-related pathologies, emphasizing the need of fine-tuning surface functionalization. Herein, we focus on the recent developments in MBGs for biomedical applications. First, the role of MBGs in the design and fabrication of three-dimensional scaffolds that fulfil the highly demanding requirements for bone tissue engineering is outlined. The different approaches for developing multifunctional MBGs are overviewed, including the incorporation of therapeutic ions in the glass composition and the surface functionalization with zwitterionic moieties to prevent bacterial adhesion. The bourgeoning scientific literature on MBGs as local delivery systems of diverse therapeutic cargoes (osteogenic/antiosteoporotic, angiogenic, antibacterial, anti-inflammatory and antitumor agents) is addressed. Finally, the current challenges and future directions for the clinical translation of MBGs are discussed.

Topical application of the plant extract SDTL-E in ovariectomized rats: A potential new approach for treating osteoporosis

Current osteoporosis medications have drawbacks of causing side effects and having slow onset, therefore developing osteoporosis drugs with faster onset and less side effects is essential. This study investigated the effects of the natural plant extract, SDTL-E, in ovariectomized (OVX)-induced osteoporosis rats. Rats were randomly assigned to sham operation control group (Control Group); OVX rat model group (Model Group) or OVX rat SDTL-E treatment group (SDTL-E Group). All groups underwent ovariectomy, but the Control Group did not have the ovaries removed. SDTL-E Group was treated with SDTL-E, Model and Control Groups were treated with vegetable oil, treatments were topically applied twice daily for 20 days. Results showed when compared with Model Group, SDTL-E Group significantly restored serum estradiol back to near Control Group level, serum ALP activity, serum and urinary calcium were significantly decreased, bone mechanics indicators increased and trabecular bone numbers slightly increased. These results demonstrated 20 days of SDTL-E topical treatment improved bone strength and trabecular bone structure in OVX-induced osteoporosis rats. The underlying mechanisms include restoring estradiol level, reducing bone turnover, net bone resorption, bone calcium loss, and calcium excretion through kidney. These findings suggest topical application of plant extract is a potential new approach with quick efficacy for treating osteoporosis.

Determination of Therapeutic and Safety Effects of Zygophyllum coccineum Extract in Induced Inflammation in Rats

Background

Z. coccineum is a facultative plant with many medicinal applications. This study examined the anti-inflammatory activity of Zygophyllum coccineum (Z. coccineum) in an arthritis animal model.

Materials and Methods

Seventy-Six Wistar Albino rats of either sex randomly divided into six groups (12/each). The inflammation model was done using Complete Freund's Adjuvant in albino rats. The anti-inflammatory activities of the extract were estimated at different dose levels (15.6, 31, and 60 mg/kg) as well as upon using methotrexate (MTX) as a standard drug (0.3 mg/kg). Paw volume and arthritis index scores have been tested in all examined animals' treatments. Histological examination of joints was also performed. Flow cytometric studies were done to isolated osteoclasts. Cytokines assay as well as biochemical testing was done in the examined samples. Results. In vitro studies reported an IC₅₀ of 15.6 μg/ml for Z. coccineum extract in lipoxygenase inhibition assay (L.O.X.). Moreover, it could be noticed that isorhamnetin-3-O-glucoside, tribuloside, and 7-acetoxy-4-methyl coumarin were the most common compounds in Z. coccineum extract separated using L.C.–ESI-TOF–M.S. (liquid chromatography-electrospray ionization ion-trap time-of-flight mass spectrometry). Microscopic examinations of synovial tissue and hind limb muscles revealed the effect of different doses of Z. coccineum extract on restoring chondrocytes and muscles structures. Osteoclast size and apoptotic rate examinations revealed the protective effect of Z. coccineum extract on osteoclast. The results upon induction of animals and upon treatment using of MTX significantly increased apoptotic rate of osteoclast compared to control, while using of 15.6 μg/ml. for Z. coccineum extract lead to recover regular apoptotic rate demonstrating the protective effect of the extract. Z. coccineum extract regulated the secretion of proinflammatory and anti-inflammatory cytokines. Biochemical tests indicated the safety of Z. coccineum extract on kidney and liver functions. Conclusion. Z. coccineum extract has efficient and safe anti-inflammatory potential in an induced rat model.

Eucommia, Cuscuta, and Drynaria Extracts Ameliorate Glucocorticoid-Induced Osteoporosis by Inhibiting Osteoclastogenesis Through PI3K/Akt Pathway

Osteoporosis is one of the most common diseases in the world which resulted in heavy socioeconomic burden and a public health threat. Glucocorticoid-induced osteoporosis (GIO) is the most common secondary reason of osteoporosis. Therapeutic strategies using traditional Chinese medicine are under investigation for osteoporosis, with efforts to improve efficacy and clarify the mechanism. The combination of Eucommia, Cuscuta, and Drynaria is widely used in traditional Chinese decoction for osteoporosis treatment, but the experimental efficacy and mechanism are still unclear. Administration of E.C.D. extracts (Eucommia, Cuscuta, and Drynaria) in experimental GIO rats resulted in decreased urinal calcium, phosphorus loss, and decreased expression of RANKL, CTX in serum, increased serum calcium, phosphorus, and OPG level. E.C.D. extracts also improved bone density, structural integrity, and biomechanical function in experimental GIO rats. These finding were associated with E.C.D. extracts’ treatment efficacy to GIO in vivo. The balance between osteoclast and osteoblast activity is essential for bone remodeling and bone related disease. The E.C.D. extracts inhibited Raw 264.7 cell differentiation to osteoclast in vitro. On the other hand, it promoted OPG expression of bone marrow mesenchymal stromal cells (MSCs) which can suppress the osteoclast genesis. E.C.D. extracts also increased the Wnt1 and Runx2 expression which are related to osteoblast formation. It also regulated the paracrine effect of MSC to inhibit osteoclast differentiation. The analysis of HPLC and comprehensive pharmacology identified the constituents of E.C.D. extracts and the potential osteoporosis-related targets mediated by E.C.D. extracts. The KEGG enrichment analysis suggested that PI3K/Akt pathway may be involved in the regulation osteoclast genesis by E.C.D. extracts and the result of Western blot of vitro assays proved it. Collectively, these data demonstrate E.C.D. extracts can inhibit osteoclast differentiation to foster experimental osteoporosis both in vivo and in vitro and it may exert the function of inhibiting osteoclast differentiation through PI3K/Akt pathway.

The Role of Macronutrients, Micronutrients and Flavonoid Polyphenols in the Prevention and Treatment of Osteoporosis

Osteoporosis is considered an age-related disorder of the skeletal system, characterized primarily by decreased bone mineral density (BMD), microstructural quality and an elevated risk of fragility fractures. This silent disease is increasingly becoming a global epidemic due to an aging population and longer life expectancy. It is known that nutrition and physical activity play an important role in skeletal health, both in achieving the highest BMD and in maintaining bone health. In this review, the role of macronutrients (proteins, lipids, carbohydrates), micronutrients (minerals—calcium, phosphorus, magnesium, as well as vitamins—D, C, K) and flavonoid polyphenols (quercetin, rutin, luteolin, kaempferol, naringin) which appear to be essential for the prevention and treatment of osteoporosis, are characterized. Moreover, the importance of various naturally available nutrients, whether in the diet or in food supplements, is emphasized. In addition to pharmacotherapy, the basis of osteoporosis prevention is a healthy diet rich mainly in fruits, vegetables, seafood and fish oil supplements, specific dairy products, containing a sufficient amount of all aforementioned nutritional substances along with regular physical activity. The effect of diet alone in this context may depend on an individual’s genotype, gene-diet interactions or the composition and function of the gut microbiota.

Role of Phenolic Compounds in Human Disease: Current Knowledge and Future Prospects

Inflammation is a natural protective mechanism that occurs when the body's tissue homeostatic mechanisms are disrupted by biotic, physical, or chemical agents. The immune response generates pro-inflammatory mediators, but excessive output, such as chronic inflammation, contributes to many persistent diseases. Some phenolic compounds work in tandem with nonsteroidal anti-inflammatory drugs (NSAIDs) to inhibit pro-inflammatory mediators' activity or gene expression, including cyclooxygenase (COX). Various phenolic compounds can also act on transcription factors, such as nuclear factor-κB (NF-κB) or nuclear factor-erythroid factor 2-related factor 2 (Nrf-2), to up-or downregulate elements within the antioxidant response pathways. Phenolic compounds can inhibit enzymes associated with the development of human diseases and have been used to treat various common human ailments, including hypertension, metabolic problems, incendiary infections, and neurodegenerative diseases. The inhibition of the angiotensin-converting enzyme (ACE) by phenolic compounds has been used to treat hypertension. The inhibition of carbohydrate hydrolyzing enzyme represents a type 2 diabetes mellitus therapy, and cholinesterase inhibition has been applied to treat Alzheimer's disease (AD). Phenolic compounds have also demonstrated anti-inflammatory properties to treat skin diseases, rheumatoid arthritis, and inflammatory bowel disease. Plant extracts and phenolic compounds exert protective effects against oxidative stress and inflammation caused by airborne particulate matter, in addition to a range of anti-inflammatory, anticancer, anti-aging, antibacterial, and antiviral activities. Dietary polyphenols have been used to prevent and treat allergy-related diseases. The chemical and biological contributions of phenolic compounds to cardiovascular disease have also been described. This review summarizes the recent progress delineating the multifunctional roles of phenolic compounds, including their anti-inflammatory properties and the molecular pathways through which they exert anti-inflammatory effects on metabolic disorders. This study also discusses current issues and potential prospects for the therapeutic application of phenolic compounds to various human diseases.

Aesculetin Accelerates Osteoblast Differentiation and Matrix-Vesicle-Mediated Mineralization

The imbalance between bone resorption and bone formation in favor of resorption results in bone loss and deterioration of bone architecture. Osteoblast differentiation is a sequential event accompanying biogenesis of matrix vesicles and mineralization of collagen matrix with hydroxyapatite crystals. Considerable efforts have been made in developing naturally-occurring plant compounds, preventing bone pathologies, or enhancing bone regeneration. Coumarin aesculetin inhibits osteoporosis through hampering the ruffled border formation of mature osteoclasts. However, little is known regarding the effects of aesculetin on the impairment of matrix vesicle biogenesis. MC3T3-E1 cells were cultured in differentiation media with 1–10 μM aesculetin for up to 21 days. Aesculetin boosted the bone morphogenetic protein-2 expression, and alkaline phosphatase activation of differentiating MC3T3-E1 cells. The presence of aesculetin strengthened the expression of collagen type 1 and osteoprotegerin and transcription of Runt-related transcription factor 2 in differentiating osteoblasts for 9 days. When ≥1–5 μM aesculetin was added to differentiating cells for 15–18 days, the induction of non-collagenous proteins of bone sialoprotein II, osteopontin, osteocalcin, and osteonectin was markedly enhanced, facilitating the formation of hydroxyapatite crystals and mineralized collagen matrix. The induction of annexin V and PHOSPHO 1 was further augmented in ≥5 μM aesculetin-treated differentiating osteoblasts for 21 days. In addition, the levels of tissue-nonspecific alkaline phosphatase and collagen type 1 were further enhanced within the extracellular space and on matrix vesicles of mature osteoblasts treated with aesculetin, indicating matrix vesicle-mediated bone mineralization. Finally, aesculetin markedly accelerated the production of thrombospondin-1 and tenascin C in mature osteoblasts, leading to their adhesion to preformed collagen matrix. Therefore, aesculetin enhanced osteoblast differentiation, and matrix vesicle biogenesis and mineralization. These findings suggest that aesculetin may be a potential osteo-inductive agent preventing bone pathologies or enhancing bone regeneration.

Terpenoid treatment in osteoporosis: this is where we have come in research

Lower bone resistance to load is due to the imbalance of bone homeostasis, where excessive bone resorption, compared with bone formation, determines a progressive osteopenia, leading to a high risk of fractures and consequent pain and functional limitations. Terpenoids, with their activities against bone resorption, have recently received increased attention from researchers. They are potentially more suitable for long-term use compared with traditional therapeutics. In this review of the literature of the past 5 years, we provide comprehensive information on terpenoids, with their anti-osteoporotic effects, highlighting molecular mechanisms that are often in epigenetic key and a possible pharmacological use in osteoporosis prevention and treatment.

Ferric ammonium citrate (FAC)-induced inhibition of osteoblast proliferation/differentiation and its reversal by soybean-derived peptides (SDP)

Ferric citrate has been used to treat hyperphosphatemia, a prevalent symptom in patients with chronic kidney disease while ferric ammonium citrate (FAC), a more dissolvable format, is widely used as food additive. However, excess iron is associated with osteoporosis. Dietary soybean products have been shown to prevent the progression of osteoporosis. In this study, a group of peptides, referred as P3, was identified from the enzymolysis of soybean protein isolates, and its biological functions were investigated. The results showed that MC3T3-E1 cell cycle progression from G0/G1 to S phase was accelerated by P3 treatment. MC3T3-E1 cell proliferation was enhanced by P3 via ERK1/2 activation. Importantly, P3 treatment abolished the antiproliferative effect of FAC on MC3T3-E1 cell. In addition, P3 treatment increased the expression of ALP, COL-1, OCN, consequently promoting the differentiation and mineralization of MC3T3-E1 cells via activation of p38 MAPK pathway. Consequently, P3 treatment was able to reverse the inhibitory effect of FAC on osteoblasts differentiation and mineralization. Our findings suggest P3, as a dietary supplement, has a potential therapeutic function to attenuate the adverse effects of FAC on bone metabolism and to prevent osteoporosis progression.

Non-flavonoid polyphenols in osteoporosis: preclinical evidence

The development of progressive osteopenia and osteoporosis (OP) is due to the imbalance between bone resorption and bone formation, determining a lower bone resistance, major risks of fractures, with consequent pain and functional limitations. Flavonoids, a class of polyphenols, have been extensively studied for their therapeutic activities against bone resorption, but less attention has been given to a whole series of molecules belonging to the polyphenolic compounds. However, these classes have begun to be studied for the treatment of OP. In this systematic review, comprehensive information is provided on non-flavonoid polyphenolic compounds, and we highlight pathways implicated in the action of these molecules that act often epigenetically, and their possible use for OP treatment and prevention.

Botanicals in Postmenopausal Osteoporosis

Osteoporosis is a systemic bone disease characterized by reduced bone mass and the deterioration of bone microarchitecture leading to bone fragility and an increased risk of fractures. Conventional anti-osteoporotic pharmaceutics are effective in the treatment and prophylaxis of osteoporosis, however they are associated with various side effects that push many women into seeking botanicals as an alternative therapy. Traditional folk medicine is a rich source of bioactive compounds waiting for discovery and investigation that might be used in those patients, and therefore botanicals have recently received increasing attention. The aim of this review of literature is to present the comprehensive information about plant-derived compounds that might be used to maintain bone health in perimenopausal and postmenopausal females.

Psoralen, a natural phytoestrogen, improves diaphyseal fracture healing in ovariectomized mice: A preliminary study

Psoralen is an effective active component extracted from Psoraleacorylifolia, which can promote bone formation in osteoporotic animals. However, to the best of our knowledge, its effect on fracture healing has not yet been examined. In the present study, open femur fractures were created in ovariectomy (OVX)-induced osteoporotic mice. OVX mice were treated with psoralen (psoralen+OVX group) or physiological saline (OVX group) by oral gavage. Radiographic and histological results demonstrated progressed callus consolidation in the psoralen+OVX group compared with the OVX group after 10 and 21 days of treatment. Qualitative histological analysis showed that the number of osteoclasts was significantly reduced in the psoralen+OVX group after treatment. Moreover, reverse transcription-quantitative PCR analysis of callus samples showed increased expression of bone morphogenetic protein-2 (BMP-2) and osteoprotegerin (OPG), and decreased expression of receptor activator of nuclear factor-κB ligand (RANKL) at 10 and 21 days post injury in the psoralen+OVX group compared with the OVX group. Furthermore, western blot analysis showed that psoralen significantly increased the expression of estrogen receptor (ER)-α, but had no effect on ER-β expression; these results were further confirmed by immunohistochemistry. To conclude, these results indicated that psoralen may promote callus formation and inhibit osteoclast genesis by increasing BMP-2 and ER-α levels, and OPG/RANKL ratio. Consequently, psoralen could be a possible treatment for osteoporotic fracture-related complications.

Flavonoids in Bone Erosive Diseases: Perspectives in Osteoporosis Treatment

Imbalance of bone homeostasis, with excessive bone resorption compared with bone formation, leads to the development of progressive osteopenia leading to lower bone resistance to load, with consequent pain and functional limitations. Phytochemicals with therapeutic and preventive effects against bone resorption have recently received increasing attention since they are potentially more suitable for long-term use than traditional therapeutic chemical compounds. In this systematic review of the literature of the past 5 years, comprehensive information is provided on flavonoids with potential antiresorption and pro-osteogenic effects. It aims to highlight the molecular mechanisms of these molecules, often epigenetic, and their possible pharmacological use, which is of great importance for the prevention and treatment of osteoporosis (OP).

A fraction of Pueraria tuberosa extract, rich in antioxidant compounds, alleviates ovariectomized-induced osteoporosis in rats and inhibits growth of breast and ovarian cancer cells

Pueraria tuberosa (Roxb. ex Willd.) DC., known as Indian Kudzu belongs to family Fabaceae and it is solicited as “Rasayana” drugs in Ayurveda. In the present study, we analyzed the efficacy of an ethyl acetate fraction from the tuber extract of Pueraria tuberosa (fraction rich in antioxidant compounds, FRAC) against menopausal osteoporosis, and breast and ovarian cancer cells. The FRAC from Pueraria tuberosa was characterized for its phenolic composition (total phenolic and flavonoid amount). Antioxidant property (in vitro assays) of the FRAC was also carried out followed by the analysis of the FRAC for its antiosteoporotic and anticancer potentials. The antiosteoporotic activity of FRAC was investigated in ovariectomy-induced osteoporosis in rats. The cytotoxicity effect was determined in breast and ovarian cancer cells. Gas chromatography/mass spectrometry (GC/MS) analysis of the FRAC was performed to determine its various phytoconstituents. Docking analysis was performed to verify the interaction of bioactive molecules with estrogen receptors (ERs). The FRAC significantly improved various biomechanical and biochemical parameters in a dose-dependent manner in the ovariectomized rats. FRAC also controlled the increased body weight and decreased uterus weight following ovariectomy in rats. Histopathology of the femur demonstrated the restoration of typical bone structure and trabecular width in ovariectomized animals after treatment with FRAC and raloxifene. The FRAC also exhibited in vitro cytotoxicity in the breast (MCF-7 and MDA-MB-231) and ovarian (SKOV-3) cancer cells. Furthermore, genistein and daidzein exhibited a high affinity towards both estrogen receptors (α and β) in the docking study revealing the probable mechanism of the antiosteoporotic activity. GC/MS analysis confirmed the presence of other bioactive molecules such as stigmasterol, β-sitosterol, and stigmasta-3,5-dien-7-one. The FRAC from Pueraria tuberosa has potential for treatment of menopausal osteoporosis. Also, the FRAC possesses anticancer activity.

A fraction of Pueraria tuberosa extract, rich in antioxidant compounds, alleviates ovariectomized-induced osteoporosis in rats and inhibits growth of breast and ovarian cancer cells

Pueraria tuberosa (Roxb. ex Willd.) DC., known as Indian Kudzu belongs to family Fabaceae and it is solicited as "Rasayana" drugs in Ayurveda. In the present study, we analyzed the efficacy of an ethyl acetate fraction from the tuber extract of Pueraria tuberosa (fraction rich in antioxidant compounds, FRAC) against menopausal osteoporosis, and breast and ovarian cancer cells. The FRAC from Pueraria tuberosa was characterized for its phenolic composition (total phenolic and flavonoid amount). Antioxidant property (in vitro assays) of the FRAC was also carried out followed by the analysis of the FRAC for its antiosteoporotic and anticancer potentials. The antiosteoporotic activity of FRAC was investigated in ovariectomy-induced osteoporosis in rats. The cytotoxicity effect was determined in breast and ovarian cancer cells. Gas chromatography/mass spectrometry (GC/MS) analysis of the FRAC was performed to determine its various phytoconstituents. Docking analysis was performed to verify the interaction of bioactive molecules with estrogen receptors (ERs). The FRAC significantly improved various biomechanical and biochemical parameters in a dose-dependent manner in the ovariectomized rats. FRAC also controlled the increased body weight and decreased uterus weight following ovariectomy in rats. Histopathology of the femur demonstrated the restoration of typical bone structure and trabecular width in ovariectomized animals after treatment with FRAC and raloxifene. The FRAC also exhibited in vitro cytotoxicity in the breast (MCF-7 and MDA-MB-231) and ovarian (SKOV-3) cancer cells. Furthermore, genistein and daidzein exhibited a high affinity towards both estrogen receptors (α and β) in the docking study revealing the probable mechanism of the antiosteoporotic activity. GC/MS analysis confirmed the presence of other bioactive molecules such as stigmasterol, β-sitosterol, and stigmasta-3,5-dien-7-one. The FRAC from Pueraria tuberosa has potential for treatment of menopausal osteoporosis. Also, the FRAC possesses anticancer activity.

Suppression of Inflammation, Osteoclastogenesis and Bone Loss by PZRAS Extract

Panax ginseng has a wide range of activities including a neuroprotective effect, skin protective effects, enhanced DNA repairing, anti-diabetic activity, and protective effects against vascular inflammation. In the present study, we sought to discover the inhibitory effects of a mixture of natural products containing Panax ginseng, Ziziphus jujube, Rubi fructus, Artemisiae asiaticae and Scutellaria baicalensis (PZRAS) on osteoclastogenesis and bone remodeling, as neither the effects of a mixture containing Panax ginseng extract, nor its molecular mechanism on bone inflammation, have been clarified yet. PZRAS upregulated the levels of catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GSH-R) and glutathione peroxidase (GSH-Px) and reduced malondialdehyde (MDA) in LPS-treated RAW264.7 cells. Moreover, treatment with PZRAS decreased the production of IL-1β and TNF-α. PZRAS also inhibited osteoclast differentiation through inhibiting osteoclastspecific genes like MMP-2, 9, cathepsin K, and TRAP in RANKL-treated RAW264.7 cells. Additionally, PZRAS has inhibitory functions on the RANKL-stimulated activation of ERK and JNK, which lead to a decrease in the expression of NFATc1 and c-Fos. In an in vivo study, bone resorption induced by LPS was recovered by treatment with PZRAS in bone volume per tissue volume (BV/TV) compared to control. Furthermore, the ratio of eroded bone surface of femurs was significantly increased in LPStreated mice compared to vehicle group, but this ratio was significantly reversed in PZRAS-treated mice. These results suggest that PZRAS could prevent or treat disorders with abnormal bone loss.

In vitro effects of the co-release of icariin and strontium from bioactive glass submicron spheres on the reduced osteogenic potential of rat osteoporotic bone marrow mesenchymal stem cells

Osteoporosis is a metabolic disease that affects bone tissue and is highly associated with bone fractures. Typical osteoporosis fracture treatments, such as bisphosphonates and hormone replacement, present important challenges because of their low bioavailability on the site of action. Options to overcome this issue are systems for the local release of therapeutic agents such as bioactive glasses containing therapeutic molecules and ions. These agents are released during the dissolution process, combining the drugs and ion therapeutic effects for osteoporosis treatment. Among the therapeutic agents that can be applied for bone repair are strontium (Sr) ion and phytopharmaceutical icariin, which have shown potential to promote healthy bone marrow stem cells osteogenic differentiation, increase bone formation and prevent bone loss. Submicron Sr-containing bioactive glass mesoporous spheres with sustained ion release capacity were obtained. Icariin was successfully incorporated into the particles, and the glass composition influenced the icariin incorporation efficiency and release rates. In this work, for the first time, Sr and icariin were incorporated into bioactive glass submicron mesoporous spheres and the in vitro effects of the therapeutic agents release were evaluated on the reduced osteogenic potential of rat osteoporotic bone marrow mesenchymal stem cells, and results showed an improvement on the reduced differentiation potential.

Therapeutic and Mechanistic Approaches of Tridax Procumbens Flavonoids for the Treatment of Osteoporosis

Homeostasis of bone is closely regulated by the balanced activities between the bone resorbing activity of osteoclast cells and bone-forming ability of osteoblast cells. Multinucleated osteoclasts degrade bone matrix and involve in the dynamic bone remodelling in coordination with osteoblasts. Disruption of this regulatory balance between these cells or any imbalance in bone remodelling caused by a higher rate of resorption over construction of bone results in a decrease of bone matrix including bone mineral density (BMD). These osteoclast-dominant effects result in a higher risk of bone crack and joint demolition in several bone-related diseases, including osteoporosis and rheumatoid arthritis (RA). Tridax procumbens is a very interesting perennial plant and its secondary metabolites called here T. procumbens flavonoids (TPFs) are well-known phytochemical agents owing to various therapeutic practices such as anti-inflammatory, anti-anaemic and anti-diabetic actions. This review designed to focus the systematic convention concerning the medicinal property and mechanism of actions of TPFs for the management of bone-related diseases. Based on the current literature, the review offers evidence-based information of TPFs for basic researchers and clinicians for the prevention and treatment of bone related diseases, including osteoporosis. It also emphasizes the medical significance for more research to comprehend the cellular signalling pathways of TPFs for the regulation of bone remodelling and discusses the possible promising ethnobotanical resource that can convey the preclinical and clinical clues to develop the next generation therapeutic agents for the treatment of bonerelated disorders.

Viburnum opulus L. Juice Phenolic Compounds Influence Osteogenic Differentiation in Human Osteosarcoma Saos-2 Cells

Bone mass loss occurs with a decrease in osteoblast proliferation and differentiation, or the enhancement of bone resorption, which further leads to the impairment of bone mineral density and increase in bone fracture. Recent studies suggest that some phenolic compounds found in food play positive role in bone metabolism. High content of phenolic compounds with potential beneficial effects on bone metabolism have been identified in the Viburnum opulus fruit. The aim of the study was to determine the influence of V. opulus fresh juice (FJ) and juice purified by solid phase extraction (PJ) on osteogenesis processes with osteosarcoma Saos-2 cell lines. V. opulus purified juice revealed stronger potential as an inducer of Saos-2 osteogenic differentiation. Saos-2 cells matrix mineralization was evaluated with alkaline phosphatase (ALP) activity measurement and alizarin red S staining. Gene expression analysis showed the elevation of the mRNA levels of Runt-related transcription factor 2 (RUNX2), ALP, collagen type 1 and osteonectin, whereas the nuclear factor-κB ligand and osteoprotegerin ratio (RANKL/OPG) decreased. Furthermore, V. opulus was able to diminish the secretion of pro-inflammatory cytokines Il6 and TNFα, however had no effect on vascular endothelial growth factor (VEGF). It decreased intracellular oxidative stress and induced DNA repair, but had no effect on the growth inhibition of lactic acid beneficial microorganisms.

Inhibitory Effect of Rosae Multiflorae Fructus Extracts on the Receptor Activator of NF-κB Ligand-Induced Osteoclastogenesis through Modulation of P38- and Ca2+-Mediated Nuclear Factor of Activated T-Cells Cytoplasmic 1 Expression

Background

Rosae Multiflorae fructus (RMF), known to have anti-inflammatory and antioxidant properties, has been used as a traditional remedy for inflammatory diseases such as arthritis in Eastern Asia. However, its effect on osteoclasts, which play a crucial role in resorptive inflammatory bone diseases, is yet to be elucidated.

Methods

The effect of extract of RMF (RMF-E) on receptor activator of nuclear factor-κB ligand (RANKL)-mediated osteoclastogenesis was examined by tartrate-resistant acid phosphatase (TRAP) staining, real-time polymerase chain reaction and western blot analysis. In addition, RANKL-induced Ca²⁺-oscillation was also investigated.

Results

RMF-E remarkably inhibited TRAP⁺-osteoclast and resorptive pit formation in a dose-dependent manner. In addition, the expression of c-Fos and nuclear factor of activated T-cells cytoplasmic, known as pivotal transcription factors for osteoclast formation in vitro and in vivo, and that of the osteoclast differentiation markers such as Acp5, Oscar, CtsK, Atp6v0d2, Tm7sf4, and Nfatc1 were significantly decreased by RMF-E treatment during osteoclastogenesis. The inhibitory effect of RMF-E on RANKL-induced osteoclastogenesis was caused by the suppression of p38 mitogen-activated protein kinase activation, and RANKL-induced Ca²⁺-oscillation removal via inactivation of Bruton's tyrosine kinase (BTK), and subsequently phospholipase C-γ2.

Conclusions

RMF-E negatively regulates osteoclast differentiation and formation. These findings suggest the possibility of RMF-E as a traditional therapeutic agent against osteoclast-related bone disorders such as osteoporosis, rheumatoid arthritis, and periodontitis.

Network Pharmacology-Based Pharmacological Mechanism of the Chinese Medicine Rhizoma drynariae Against Osteoporosis

Rhizoma drynariae is the main traditional Chinese medicine used for the treatment of osteoporosis, but its anti-osteoporotic targeting mechanism has not been fully elucidated due to the complexity of its active ingredients. In this study, the pharmacological mechanism of action of Rhizoma drynariae against osteoporosis was studied by integrating pharmacological concepts.

The pharmacokinetic characteristics of selected major active constituents of Rhizoma drynariae and the SMILES structural similarity were used to predict related targets. A literature search was conducted to identify known osteoporosis treatment targets, which were then combined with the predicted targets to construct the direct or indirect target interaction network map of Rhizoma drynariae against osteoporosis. Finally, data on the key targets of the interactions, ranked according to relevant node parameters obtained through pathway enrichment analysis and screening of key targets and active ingredients of Rhizoma drynariae, were used to perform molecular docking simulation.

We screened 16 active ingredients of Rhizoma drynariae, and 7 key targets with direct or indirect effects with a high frequency were obtained. These main pathways were found to play important roles in the PI3k-akt signaling pathway, osteoclast differentiation, Wnt signaling pathway, and estrogen signaling pathway. Molecular docking showed that most active ingredients of Rhizoma drynariae had strong binding efficiency with key targets.

Based on network pharmacology, we conclude that Rhizoma drynariae plays an anti-osteoporotic role by directly or indirectly targeting multiple major signaling pathways and influencing the proliferation and differentiation of multiple types of cells.

Grapefruit juice exerts anti-osteoporotic activities in a prednisolone-induced osteoporosis rat femoral fracture model, possibly via the RANKL/OPG axis

This study aimed to shed light on the protective and therapeutic anti-osteoporotic effects and mechanisms of action of grapefruit juice (GFJ) on prednisolone-induced osteoporosis a rat femoral fracture model. We found that treating rats with GFJ before and/or after prednisolone-induced osteoporosis resulted in increased bone density, total mineral content, and calcium content to counteract the osteoporotic effects of prednisolone. In parallel, the histological and ultrastructural results of the GFJ-treated groups correlated well with enhanced breaking strength of femurs subjected to a constant load. Furthermore, GFJ treatment before and after prednisolone-induced osteoporosis decreased plasma alkaline phosphatase and tartrate-resistant acid phosphatase activities and increased the level of insulin-like growth factor 1. Mechanistically, our immunohistochemistry study showed that GFJ ameliorated prednisolone-induced osteocalcin depletion, decreased receptor activator of nuclear factor kappa-B ligand (RANKL) expression, and increased osteoprotegerin (OPG) expression. GFJ showed a beneficial anti-osteoporotic effect against prednisolone-induced osteoporosis in rats, possibly via the RANKL/OPG axis, suggesting that GFJ might be a good candidate for developing anti-osteoporotic drugs.

Discovery of potential sclerostin inhibitors from plants with loop2 region of sclerostin inhibition by interacting with residues outside Pro-Asn-Ala-Ile-Gly motif

Sclerostin, an antagonist of the Wnt/β-catenin signaling pathway, was discovered as a potential therapeutic target for stimulating bone formation in osteoporosis. In this study, molecular docking was employed to predict the binding of 29 herbal compounds, which were reported as bone formation stimulators, to the loop2 region of sclerostin. Then, the 50 ns molecular dynamics (MD) simulation of the complexes between sclerostin and the top 10 hits obtained from molecular docking were carried out. Root mean square deviations (RMSDs) analysis of MD trajectories pointed out that all ligands-complexes remain stable throughout the duration of MD simulations. In addition, the molecular mechanics/generalized born surface area (MM/GBSA) binding free energy and energy decomposition analyses were determined. The results here suggested that baicalin is the most promising inhibitor of sclerostin. Interestingly, baicalin binds to sclerostin via the hydrophobic interaction with the amino acid residues on loop2 region but outside the Pro-Asn-Ala-Ile-Gly (PNAIG) motif, particularly the Arg-Gly-Lys-Trp-Trp-Arg (RGKWWR) motif. This finding could be a novel strategy for developing new sclerostin inhibitors in the future.Communicated by Ramaswamy H. Sarma.

Osteoprotective Effects of Tribulus terrestris L.: Relationship Between Dehydroepiandrosterone Levels and Ca2+-Sparing Effect

Osteoporosis is a systemic bone disease that is characterized by impairments in bone strength that predispose an individual to a higher risk of fractures. Despite the various etiologies, undoubtedly the most important factors are aging of the population and hypogonadism. Although several therapeutic options are available, pharmacological treatments have some risks. Among these are increases in the incidence of thrombosis, breast cancer, ovarian cancer, endometrial cancer, and muscle injury, among others. Herbal medication may be an alternative for the treatment of osteoporosis. Thus, the aim of this study was to evaluate the therapeutic effect of a standardized extract of Tribulus terrestris L. (TT) on ovariectomy (OVX)-induced bone loss in rats. Female rats were first subjected to OVX and treated with TT (3, 30, and 300 mg/[kg·day]) or furosemide (25 mg/kg) orally for 28 days. Bone densitometry and tibial histology were performed, and acute renal function and testosterone, dehydroepiandrosterone (DHEA), and estradiol levels were assessed. Prolonged treatment with TT stimulated bone mass gain in all ovariectomized animals, raising bone mass to levels that were similar to sham-operated rats. DHEA levels significantly increased in TT-treated rats. The TT group also had lower calcium (Ca²⁺) excretion that OVX control and furosemide-treated rats. Finally, the histopathological analyses showed the maintenance of bone turnover in all TT-treated groups. Overall, the results indicate that the standardized extract of T. terrestris exerted a bone-protective effect by increasing bone mineral density. This activity may be at least partially attributable to an increase in serum DHEA levels and a Ca²⁺-sparing effect.

Systems pharmacology reveals the unique mechanism features of Shenzhu Capsule for treatment of ulcerative colitis in comparison with synthetic drugs

In clinic, both synthetic drugs and Shenzhu Capsule (SZC), one kind of traditional Chinese medicines (TCMs), are used to treat ulcerative colitis (UC). In our study, a systems pharmacology approach was employed to elucidate the chemical and mechanism differences between SZC and synthetic drugs in treating UC. First, the compound databases were constructed for SZC and synthetic drugs. Then, the targets of SZC were predicted with on-line tools and validated using molecular docking method. Finally, chemical space, targets, and pathways of SZC and synthetic drugs were compared. Results showed that atractylenolide I, atractylone, kaempferol, etc., were bioactive compounds of SZC. Comparison of SZC and synthetic drugs showed that (1) in chemical space, the area of SZC encompasses the area of synthetic drugs; (2) SZC can act on more targets and pathways than synthetic drugs; (3) SZC can not only regulate immune and inflammatory reactions but also act on ulcerative colitis complications (bloody diarrhea) and prevent UC to develop into colorectal cancer whereas synthetic drugs mainly regulate immune and inflammatory reactions. Our study could help us to understand the compound and mechanism differences between TCM and synthetic drugs.

Total flavonoid extract of Epimedium herb increases the peak bone mass of young rats involving enhanced activation of the AC10/cAMP/PKA/CREB pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Epimedium sagittatum brevicornum Maxim. is an important traditional Chinese herb that has long been used to promote bone fracture healing and treat osteoporosis.

AIM OF THE STUDY

Achieving peak bone mass by adolescence has now been accepted to be fundamental for preventing osteoporosis in adulthood life. This study investigated the possibility of increasing peak bone mass in young rats using the total flavonoid extract of Epimedium herb (TFE).

MATERIALS AND METHODS

TFE was intragastrically administered to one-month-old Wistar rats at a low (100 mg/kg), middle (200 mg/kg) or high dose (400 mg/kg). Whole body bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry every two weeks. When BMD of any one of TFE groups was found to be significantly higher than that of the control, all rats were sacrificed, serum samples were collected for bone turnover biochemical assays, and femurs, tibiae and vertebrae were isolated and used in BMD, mechanical, micro-structural, histomorphometric and mechanistic studies.

RESULTS

Administration of TFE at middle and high doses for two months significantly increased the whole body, femoral and vertebral BMDs, and improved the bone mechanical and micro-architectural properties. The serum turnover biochemical results and the enhanced expression levels of bone-formation regulatory genes (Runx-2, OSX, and BMP-2) demonstrated that TFE administration increased bone formation but had no effect on bone resorption. The increased phosphorylation levels in femurs of PKA and CREB and expression of AC10 (the only soluble form of adenylyl cyclase) and the increased serum cAMP level after 4 h of TFE administration indicated that TFE promoted bone formation by activating the AC10/cAMP/PKA/CREB pathway in vivo.

CONCLUSIONS

Oral administration of TFE at 200 mg/kg for two months can increase the peak bone mass of growing rats, suggesting the possibility of using total flavonoid extract of Epimedium herb to increase the peak bone mass in adolescence which is important for preventing osteoporosis in adult life.

Tanshinone IIA protects against polyethylene particle-induced osteolysis response in a mouse calvarial model

The expression of β-catenin in detectable aseptic loosening after joint replacement and the surrounding osteolysis of the prosthesis is primarily caused by the abrasive particles introduced by the prosthesis, which results in a shortened service life of the prosthesis. Recent studies have shown that debris can induce many cytokines associated with osteolysis. In particular, RANKL directly stimulates osteoclast formation and activity. Thus, we hypothesize that the osteolysis induced by wear particles can be prevented by inhibiting the RANKL signaling pathway. In this study, we established a C57BL/J6 mouse calvarial model of PE granule induced osteolysis, and studied the inhibitory action of tanshinone IIA on osteoclast formation. Eight-week-old male c57BL/J6 mouse were randomly divided into four groups: Sham group (no PE particle-induced + PBS), positive group (PE particle-inducted + PBS), low dose group (PE particle-induced + 1 ug/g tanshinone IIA), and high-dose group (PE granule-induced + 2 ug/g tanshinone II). After 21 days, the mice were executed and the calvaria were collected and processed for micro-CT scan and histomorphometry analysis. Compared to the positive subgroup, Tanshinone IIA significantly reduced bone absorption induced by PE granules and inhibited the formation and activity of osteoclasts. In addition, ELISA test showed that tanshinone IIA significantly reduced OSCAR and CTX-1 expression. Further, tanshinone IIA enhanced the formation of OPG, thus reducing osteoclast damage to the bone around the implant. Overall, these data indicate that tanshinone IIA represents a promising drug for the treatment of bone absorption by particles and can be a new method of treatment for prophylaxis of aseptic loosening.

The Prevention and Therapy of Osteoporosis: A Review on Emerging Trends from Hormonal Therapy to Synthetic Drugs to Plant-Based Bioactives

Osteoporosis is one of the major health problems worldwide. It is characterized by increased bone fragility and loss of bone matter due to the action of osteoclast cells, which are associated with modified hormone levels and factors such as aging. Bisphosphonates are the primary treatment for osteoporosis. Apart from bisphosphonates, hormone therapy, calcitonin treatment, selective estrogen receptor modulators (SERMs), and strontium ranelate (SR) are some of the other treatments available for osteoporosis. However, these treatments have some side effects, such as oily skin, fluid retention, nausea, long-term toxicity, and even prostate cancer in males, and thus natural therapies that incur fewer side effects are sought. Phytochemicals, antioxidants, and other plant-based bioactives are important in the human diet. They are abundant in fruits and help against various chronic diseases, including bone disorders. Other providers of these important compounds are the medicinal plant parts. In this article, we highlight the various species of plants and herbs that are useful for the treatment of osteoporosis. The prospect of using these plant-based bioactives in amelioration of osteoporosis as an alternative to hormonal and synthetic drug-based therapy is also discussed.

Inhibitory effects of methyl-3,5-di-O-caffeoyl-epi-quinate on RANKL-induced osteoclast differentiation

In this study, we have shown that methyl-3,5-di-O-caffeoyl-epi-quinate, a naturally occurring compound isolated from Ainsliaea acerifolia, inhibits receptor activator of nuclear factor-κB ligand (RANKL)-induced formation of multinucleated tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts and the expression of osteoclast marker genes. Methyl-3,5-di-O-caffeoyl-epi-quinate also inhibited RANKL-induced activation of p38, Akt and extracellular signal-regulated kinase (ERK) as well as the expression of nuclear factor of activated T-cell (NFATc1), the key regulator of osteoclast differentiation. Negative regulators for osteoclast differentiation was upregulated by methyl-3,5-di-O-caffeoyl-epi-quinate. Collectively, our results suggested that methyl-3,5-di-O-caffeoyl-epi-quinate suppresses osteoclast differentiation via downregulation of RANK signaling pathways and NFATc1.

Protective Effects of Selected Botanical Agents on Bone

Osteoporosis is a serious health problem affecting more than 200 million elderly people worldwide. The early symptoms of this disease are hardly detectable. It causes progressive bone loss, which ultimately renders the patients susceptible to fractures. Osteoporosis must be prevented because the associated fragility fractures result in high morbidity, mortality, and healthcare costs. Many plants used in herbal medicine contain bioactive compounds possessing skeletal protective effects. This paper explores the anti-osteoporotic properties of selected herbal plants, including their actions on osteoblasts (bone forming cells), osteoclasts (bone resorbing cells), and bone remodelling. Some of the herbal plant families included in this review are Berberidaceae, Fabaceae, Arecaceae, Labiatae, Simaroubaceaea, and Myrsinaceae. Their active constituents, mechanisms of action, and pharmaceutical applications were discussed. The literature shows that very few herbal plants have undergone human clinical trials to evaluate their pharmacological effects on bone to date. Therefore, more intensive research should be performed on these plants to validate their anti-osteoporotic properties so that they can complement the currently available conventional drugs in the battle against osteoporosis.

Effects of Curcumin on Bone Loss and Biochemical Markers of Bone Turnover in Patients with Spinal Cord Injury

BACKGROUND

Osteoporosis is one of the most common problems of patients with spinal cord injuries (SCIs). The current study aimed to evaluate the antiosteoporotic effects of curcumin on densitometry parameters and biomarkers of bone turnovers among patients with SCI.

MATERIALS AND METHODS

The current controlled clinical trial was conducted among 100 patients with SCI referred to an outpatient clinic of rehabilitation in Ilam City, Iran, in 2013-2015. The intervention group received 110/mg/kg/day curcumin for 6 months and the control group received placebo. Bone mineral density (BMD) was measured in all patients. The level of procollagen type I N-terminal propeptide, serum carboxy-terminal telopeptide of type I collagen, osteocalcin, and bone-specific alkaline phosphates were compared before and after study.

RESULTS

BMD indicators of lumbar, femoral neck, and total hip in the control group significantly decreased compared with the beginning of study. However, in the curcumin group, a significant increase was observed in BMD indicators of lumbar, femoral neck, and hip at the end of study compared with the beginning. There was also a significant difference between interventional and control groups for the mean BMD of femoral neck and hip at the end of study (0.718 ± 0.002 g/cm² vs. 0.712 ± 0.003 g/cm² and 0.742 ± 0.031 g/cm² vs. 0.692 ± 0.016 g/cm², respectively).

CONCLUSIONS

Curcumin, via modulation of densitometry indices and bone resorption markers, showed inhibitory effects on the process of osteoporosis. Treatment with curcumin was significantly associated with a decrease in the osteoporosis progression and bone turnover markers of patients with SCI after 6 months.

Ethanolic Extract of Rubus coreanus Fruits Inhibits Bone Marrow-Derived Osteoclast Differentiation and Lipopolysaccharide-Induced Bone Loss

The inhibition of osteoclast differentiation/bone resorption is a well-known therapeutic strategy for controlling pathological and postmenopausal bone loss. Natural products that specifically inhibit osteoclastogenesis could therefore be developed as antiresorptive drugs for the treatment of metabolic bone disorders characterized by excessive osteoclastic bone resorption. We therefore examined the effects of Rubus coreanus extract (eeRc) on receptor activator of nuclear factor kappa-B ligand (RANKL)-induced differentiation of bone marrow macrophages (BMMs) into osteoclasts and pit formation in vitro. Additionally, the in vivo effects of the eeRc were observed in mice with lipopolysaccharide (LPS)-induced bone erosion. In this study, we found that the ethanolic extract of Rubus coreanus fruits considerably suppressed the RANKL-induced differentiation of primary BMMs into osteoclasts and bone-resorbing activity of mature osteoclasts. Oral administration of eeRc attenuated LPS-induced bone loss in vivo, as demonstrated by the reversal of LPS-induced reduction in bone volume per tissue volume, bone mineral density, and trabecular number to some extent in eeRc-treated mice. In addition, eeRc slightly decreased the serum levels of C-terminal telopeptide fragments of type I collagen, the collagen-breakdown product generated by osteoclasts. Collectively, our results indicate that eeRc has the potential to inhibit bone loss by blocking osteoclast differentiation and could therefore be a promising natural product for the prevention and/or treatment of inflammatory bone loss.

Evaluation of anti-osteoporotic activity of butanolic fraction from Passiflora foetida in ovariectomy-induced bone loss in mice

OBJECTIVE

In this study, we have evaluated the skeletal effects of butanolic fraction (BF) from Passiflora foetida in an estrogen deficient mice bone loss model.

STUDY DESIGN

Skeletal effect of BF was studied in ovariectomized (OVx) female Balb/c mice. BF (50 and 100mg/kg/day dose orally) was given for 8 weeks. Micro-architecture of long bones, biomechanical strength, formations of mineralized nodule by bone marrow osteoprogenitor cells, osteoid formation and bone turnover markers were studied. One way ANOVA was used to test the significance of effects of Passiflora foetida.

RESULTS

OVx mice treated with BF represented with better micro-architectural parameters at various anatomical positions, better bone biomechanical strength and more osteoprogenitor cells in the bone marrow compared with OVx group. BF did not exhibit uterine estrogenicity.

CONCLUSION

Oral administration of BF at both the doses (50 and 100mg/kg/day) derived from Passiflora Foetida, was found to afford anti-osteoporotic effect under estrogen deficiency by likely stimulation of osteoblast function and inhibition of osteoclast function.

Stereological investigation of the effect of Elaeagnus angustifolia fruit hydroalcoholic extract on osteoporosis in ovariectomized rats

OBJECTIVE

Postmenopausal osteoporosis is characterized by increased fracture risk. However, each approved treatment has specific side effects. Therefore, foods with plant origins have increasingly attracted attention as an alternative treatment. Studies have shown that Elaeagnus angustifolia (EA) has antioxidant properties. The present study aimed to investigate the effects of EA hydroalcoholic extract on ovariectomy-induced osteoporosis in rats using stereological methods.

MATERIAL AND METHODS

55 female Sprague-Dawley rats were randomly assigned to control, sham operated (normal saline), ovariectomized (OVX), OVX + EA fruit extract (600 mg/kg BW/day), and OVX + estradiol benzoate (3 mg/kg BW) for 16 weeks. Blood samples were collected to measure calcium, phosphorus, and alkaline phosphatase (ALP) plasma levels. Then, specimens from tibia and fifth lumbar vertebra (L5) bones were prepared and stereological analysis was done.

RESULTS

Ovariectomy significantly decreased the calcium level and increased the ALP level in the OVX group. In spite of improvement in calcium hemostasis in groups treated with estrogen and EA fruit extract (p<0.05), only treatment with estrogen was able to reduce ALP levels. Moreover, treatment with EA fruit extract and estrogen caused a significant increase in the number of osteoblasts in vertebra and tibia compared to the OVX group (p<0.05). Estrogen and EA fruit extract were also able to reduce the number of osteoclasts in tibia of the treated OVX rats (p<0.05).

CONCLUSION

The results showed that EA extract exerted more effects, markedly, on osteoblastogenesis in the OVX rats. Thus, it could be considered as a potential agent to treat patients with osteoporosis.

Comparative proteomic and metabolomic analysis reveal the antiosteoporotic molecular mechanism of icariin from Epimedium brevicornu maxim

ETHNOPHARMACOLOGICAL RELEVANCE

Icariin, a principal flavonoid glycoside of Epimedium brevicornu Maxim, has been widely proved to possess antiosteoporotic activity with promoting bone formation and decreasing bone resorption. However, the involving mechanisms remain unclear.

AIM OF THE STUDY

To clear a global insight of signal pathways involved in anti-osteoporotic mechanism of icariin at proteins and metabolites level by integrating the proteomics and NMR metabonomics, in a systems biology approach.

MATERIAL AND METHODS

Mice were divided into sham, OVX model and icariin-treated OVX group, after 90 days treatment, difference gel electrophoresis combined with MALDI-TOF/TOF proteomics analysis on bone femur and serum metabolomics were carried out for monitor intracellular processes and elucidate anti-osteoporotic mechanism of icariin. Osteoblast and osteoclast were applied to evaluate the potential signal pathways.

RESULTS

Twenty three proteins in bone femur, and 8 metabolites in serum, were significantly altered and identified, involving in bone remodeling, energy metabolism, cytoskeleton, lipid metabolism, MAPK signaling, Ca²⁺ signaling et, al. Furthermore, animal experiment show icariin could enhance the BMD and BMC, decrease CTX-I level in ovariectomized mice. The mitochondrial membrane potential and the intracellular ATP levels were increased significantly, and the cytoskeleton were improved in icariin-treatment osteoblast and osteoclast. Icariin also increased mRNA expression of Runx2 and osterix of OB, decreased CTR and CAII mRNA expression and protein expression of P38 and JNK. However, icariin did not reveal any inhibition of the collagenolytic activity of cathepsin K, mRNA expression of MMP-9 and protein expression of ERK in osteoclast.

CONCLUSION

we consider icariin as multi-targeting compounds for treating with osteoporosis, involve initiating osteoblastogenesis, inhibiting adipogenesis, and preventing osteoclast differentiation.

Traditional Chinese medicine formulas for the treatment of osteoporosis: Implication for antiosteoporotic drug discovery

ETHNOPHARMACOLOGICAL RELEVANCE

Osteoporosis is a chronic epidemic which can leads to enhanced bone fragility and consequent an increase in fracture risk. Traditional Chinese medicine (TCM) formulas have a long history of use in the prevention and treatment of osteoporosis. Antiosteoporotic TCM formulas have conspicuous advantage over single drugs. Systematic data mining of the existing antiosteoporotic TCM formulas database can certainly help the drug discovery processes and help the identification of safe candidates with synergistic formulations. In this review, the authors summarize the clinical use and animal experiments of TCM formulas and their mechanism of action, and discuss the potential antiosteoporotic activity and the active constituents of commonly used herbs in TCM formulas for the therapy of osteoporosis.

MATERIALS AND METHODS

The literature was searched from Medline, Pubmed, ScienceDirect, Spring Link, Web of Science, CNKI and VIP database from 1989 to 2015, and also collected from Chinese traditional books and Chinese Pharmacopoeia with key words such as osteoporosis, osteoblast, osteoclast, traditional Chinese medicine formulas to identify studies on the antiosteoporotic effects of TCM formulas, herbs and chemical constituents, and also their possible mechanisms.

RESULTS

Thirty-three TCM formulas were commonly used to treat osteoporosis, and showed significant antiosteoporotic effects in human and animal. The herb medicines and their chemical constituents in TCM formulas were summarized, the pharmacological effects and chemical constituents of commonly used herbs in TCM formulas were described in detail. The action mechanisms of TCM formulas and their chemical constituents were described. Finally, the implication for the discovery of antiosteoporotic leads and combinatory ingredients from TCM formulas were prospectively discussed.

CONCLUSIONS

Clinical practice and animal experiments indicate that TCM formulas provide a definite therapeutic effect on osteoporosis. The active constituents in TCM formulas are diverse in chemical structure, and include flavonoids, lignans, saponins and iridoid glycosides. Antiosteoporotic mechanism of TCM formulas and herbs involves multi regulatory pathways, such as Wnt/β-catenin, BMP/Smad, MAPK pathway and RANKL/OPG system. Phytochemicals from TCM formulas and their compositional herb medicines offer great potential for the development of novel antiosteoporotic drugs. The active ingredients in TCM formulas can be developed in combination as potent drugs, which may exhibit better antiosteoporotic effects compared to the individual compound.

Rhus javanica Gall Extract Inhibits the Differentiation of Bone Marrow-Derived Osteoclasts and Ovariectomy-Induced Bone Loss

Inhibition of osteoclast differentiation and bone resorption is a therapeutic strategy for the management of postmenopausal bone loss. This study investigated the effects of Rhus javanica (R. javanica) extracts on bone marrow cultures to develop agents from natural sources that may prevent osteoclastogenesis. Extracts of R. javanica (eGr) cocoons spun by Rhus javanica (Bell.) Baker inhibited the osteoclast differentiation and bone resorption. The effects of aqueous extract (aeGr) or 100% ethanolic extract (eeGr) on ovariectomy- (OVX-) induced bone loss were investigated by various biochemical assays. Furthermore, microcomputed tomography (µCT) was performed to study bone remodeling. Oral administration of eGr (30 mg or 100 mg/kg/day for 6 weeks) augmented the inhibition of femoral bone mineral density (BMD), bone mineral content (BMC), and other factors involved in bone remodeling when compared to OVX controls. Additionally, eGr slightly decreased bone turnover markers that were increased by OVX. Therefore, it may be suggested that the protective effects of eGr could have originated from the suppression of OVX-induced increase in bone turnover. Collectively, the findings of this study indicate that eGr has potential to activate bone remodeling by inhibiting osteoclast differentiation and bone loss.

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.

Anti-osteoporosis effect of Epimedium via an estrogen-like mechanism based on a system-level approach

ETHNOPHARMACOLOGICAL RELEVANCE

Epimedium is a popular traditional herbal medicine worldwide that has long been used to relieve osteoporosis. The estrogenic properties of the herb are conferred by several phytoestrogens, such as flavonoids, lignans, and steroids. However, the poor understanding on the estrogen-like mechanism of Epimedium at the molecular and system levels limits the applications of this herb in osteoporosis treatment.

MATERIALS AND METHODS

In this study, systems pharmacology was established to investigate the relationship between Epimedium and estrogen against osteoporosis by integrating active component screening, drug-likeness evaluation, herb feature mapping, target prediction and validation, and network analysis.

RESULTS

A total of 77 active components that possessed similar structural features to estrogen as determined using herb feature mapping were selected from Epimedium by oral bioavailability prediction and drug-likeness evaluation. Twenty three osteoporosis-related targets were obtained from the active components of Epimedium as potential targets, 11 of which were common targets with estrogen. All osteoporosis-related targets were further mapped to compound-target and target-pathway networks. Results displayed that Epimedium can exert anti-osteoporosis effects by directly regulating the 11 estrogen-related targets and a set of target proteins on five estrogen-related pathways.

CONCLUSION

This study explained the estrogen-like mechanism of Epimedium in preventing and treating osteoporosis, and provided a new standpoint for exploring the traditional herbal medicine against osteoporosis.