Potential Anti-osteoporotic Agent Research Articles

Effect of Hydro-Ethanolic Extract of Cardiospermum halicacabum Linn. on Human Osteoblast Like Cells, MG-63 and Phytochemical Profiling by GC-MS

Background: Ancient Indian Ayurvedic literature prescribes Cardiospermum halicacabum as a remedy for rheumatism, lumbago, stiffness of limbs and allied diseases of musculo-skeletal system. Aim: The present study is to investigate the anti-osteoporotic potential of hydro-ethanolic extract of Cardiospermum halicacabum Linn. on human osteoblast-like cells (MG-63) and their phytochemicals are profiled by GC-MS. Materials and methods: Cell proliferation rate was assessed by standard colorimetric MTT assay on human osteoblast-like cells (MG-63). The osteoblastic and osteoclastic activities in MG-63 cell line were determined by assaying of bone markers like Alkaline phosphatase (ALP) and Lactate dehydrogenase (LDH). Results: The hydro-ethanolic extract of Cardiospermum halicacabum shows a significant increase in both proliferation and ALP activity in osteoblasts, and decreased LDH leakage in the supernatant of cultured human osteoblast-like cells (MG-63). The GC-MS analysis of hydro-ethanolic extract of C. halicacabum revealed the presence of more than 70 phytoconstituents. Conclusion: Hydro-ethanolic extract of Cardiospermum halicacabum showed a potential influence on osteogenesis and hence its use could be explored as a potential anti-osteoporotic agent.

Bioavailability, tissue distribution and excretion studies of a potential anti-osteoporotic agent, medicarpin, in female rats using validated LC–MS/MS method

Medicarpin, one of the active constituents isolated from the extract of Butea monosperma, has been shown to have various pharmacological activities including potent anti-osteoporotic properties. The aim of this study was to investigate the oral pharmacokinetics, tissue distribution and excretion of medicarpin following single oral dose administration in female rats. Oral pharmacokinetics was explored at 5 and 20 mg/kg while tissue distribution, urinary and fecal excretion were studied following 20 mg/kg oral dose. Medicarpin was quantified in rat plasma, urine, feces and tissue samples using a validated LC–MS/MS method following reverse-phase HPLC separation on RP18 column (4.6 mm × 50 mm, 5.0 μm) using methanol and 10 mM ammonium acetate (pH 4.0) as mobile phase in the ratio of 80:20 (v/v) at a flow rate of 0.8 mL/min. The oral bioavailability of medicarpin was found to be low with low systemic levels. The concentration in tissues was significantly higher than plasma. Highest tissue concentrations were found in the liver followed by bone marrow. Urinary and fecal excretion of medicarpin was < 1 %. In conclusion, medicarpin was found to be highly distributed in body tissues and minimally excreted via urine or feces.

Osteoporosis: Possible Pathways Involved and the Role of Natural Phytoestrogens in Bone Metabolism

The incidence of post-menopausal osteoporosis is increasing globally. In post-menopausal osteoporosis, there is deficiency in oestrogen level resulting in bone loss and fractures. Bone formation is under the control of different hormones. In the present review, we highlight few pathways such as RANKL/RANK, apoptosis and Wnt/β-catenin signalling pathways and phytoestrogens involved in the bone metabolism. RANKL/RANK signalling is responsible for regulating the formation and activation of multinucleated osteoclasts from their precursors which is responsible for the survival of normal bone remodelling. Apoptosis regulates the development, growth and maintains the bone tissues. The Wnt pathway is an important pharmacological target for bone anabolic drugs and its future discovery. In today’s world, herbal remedies are used to treat post-menopausal osteoporosis as these products contain phytoestrogens. These phytoestrogens are oestrogen like compounds which influence bone metabolism. The phytoestrogens provide better therapeutic effect in reducing the RANKL, osteoclastogenesis, inflammatory markers, and increase the osteogenic markers in the bone cells or osteoblasts. We discuss the mechanism of action of few phytoestrogens such as genistein, daidzein and equol which are beneficial for improvement of the bone health. Daidzein enhances osteoblast growth via the upregulation of BMP expression in primary osteoblast cells and it is a potential antiosteoporotic agent. Genistein also possesses antioestrogenic property by virtue of its competitive binding to the same receptors as oestradiol. Equol regulates the bone loss via hemopoiesis and inflammatory cytokine production. Thus, phytoestrogens could be efficiently used as osteoprotective agents for the treatment of individuals with post-menopausal osteoporosis.

Effect of tocotrienol from Bixa orellana (annatto) on bone microstructure, calcium content, and biomechanical strength in a model of male osteoporosis induced by buserelin.

BackgroundPatients receiving androgen deprivation therapy experience secondary hypogonadism, associated bone loss, and increased fracture risk. It has been shown that tocotrienol from Bixa orellana (annatto) prevents skeletal microstructural changes in rats experiencing primary hypogonadism. However, its potential in preventing bone loss due to androgen deprivation therapy has not been tested. This study aimed to evaluate the skeletal protective effects of annatto tocotrienol using a buserelin-induced osteoporotic rat model.MethodsForty-six male Sprague Dawley rats aged 3 months were randomized into six groups. The baseline control (n=6) was sacrificed at the onset of the study. The normal control (n=8) received corn oil (the vehicle of tocotrienol) orally daily and normal saline (the vehicle of buserelin) subcutaneously daily. The buserelin control (n=8) received corn oil orally daily and subcutaneous buserelin injection (75 µg/kg) daily. The calcium control (n=8) was supplemented with 1% calcium in drinking water and daily subcutaneous buserelin injection (75 µg/kg). The remaining rats were given daily oral annatto tocotrienol at 60 mg/kg (n=8) or 100 mg/kg (n=8) plus daily subcutaneous buserelin injection (75 µg/kg) (n=8). At the end of the experiment, the rats were euthanized and their blood, tibia, and femur were harvested. Structural changes of the tibial trabecular and cortical bone were examined using X-ray micro-computed tomography. Femoral bone calcium content and biomechanical strength were also evaluated.ResultsAnnatto tocotrienol at 60 and 100 mg/kg significantly prevented the deterioration of trabecular bone and cortical thickness in buserelin-treated rats (P<0.05). Both doses of annatto tocotrienol also improved femoral biomechanical strength and bone calcium content in buserelin-treated rats (P<0.05). The effects of annatto tocotrienol were comparable to calcium supplementation.ConclusionAnnatto tocotrienol supplementation is effective in preventing degeneration of the bone induced by buserelin. Therefore, it is a potential antiosteoporotic agent for men receiving androgen deprivation therapy.

Indirubin-3′-Oxime Reverses Bone Loss in Ovariectomized and Hindlimb-Unloaded Mice Via Activation of the Wnt/β-Catenin Signaling

Osteoporosis is a major global health issue in elderly people. Because Wnt/β-catenin signaling plays a key role in bone homeostasis, we screened activators of this pathway through cell-based screening, and investigated indirubin-3'-oxime (I3O), one of the positive compounds known to inhibit GSK3β, as a potential anti-osteoporotic agent. Here, we show that I3O activated Wnt/β-catenin signaling via inhibition of the interaction of GSK3β with β-catenin, and induced osteoblast differentiation in vitro and increased calvarial bone thickness ex vivo. Intraperitoneal injection of I3O increased bone mass and improved microarchitecture in normal mice and reversed bone loss in an ovariectomized mouse model of age-related osteoporosis. I3O also increased thickness and area of cortical bone, indicating improved bone strength. Enhanced bone mass and strength correlated with activated Wnt/β-catenin signaling, as shown by histological analyses of both trabecular and cortical bones. I3O also restored mass and density of bone in hindlimb-unloaded mice compared with control, suspended mice, demonstrating bone-restoration effects of I3O in non-aged-related osteoporosis as well. Overall, I3O, a pharmacologically active small molecule, could be a potential therapeutic agent for the treatment and prevention of osteoporosis.

A Review of the Possible Mechanisms of Action of Tocotrienol – A Potential Antiosteoporotic Agent

Osteoporosis is posing a tremendous healthcare problem globally. Much effort has been invested in finding novel antiosteoporotic agents to stop the progression of this disease. Tocotrienol, one of the isoforms of vitamin E, is poised as a potential antiosteoporotic agent. Previous studies showed that tocotrienol as a single isomer or as a mixture demonstrated both anabolic and antiresorptive effects in various rodent models of osteoporosis. In vitro experiments further demonstrated that tocotrienol could up-regulate genes related to osteoblastogenesis and modify receptor activator of nuclear factor kappa B signaling against osteoclastogenesis. Additionally, tocotrienol was also shown to be a strong 3- hydroxy-3-methyl-glutaryl-CoA reductase down-regulator with a mechanism different from that of statins. Inhibition of the mevalonate pathway affects both osteoblast and osteoclast formation in favor of the former. Tocopherol, a more commonly used isoform of vitamin E does not possess similar effects. Tocotrienol is also a potent antioxidant. It can scavenge free radicals and prevent oxidative damage on osteoblast thus promoting its survival. It may also up-regulate the antioxidant defense network in osteoclast and indirectly act against free radical signaling essential in osteoclastogenesis. The effects of tocotrienol on Wnt/β-catenin signaling essential in osteoblastogenesis have not been determined. More mechanistic studies need to be conducted to illustrate the antiosteoporotic effects of tocotrienol. Clinical trials are also required to confirm its effects in humans. In conclusion, tocotrienol demonstrates great potential as an antiosteoporotic agent and much research effort should be invested to develop it as an agent to curb osteoporosis.

Drug Delivery Systems for Prevention and Treatment of Osteoporotic Fracture

Anti-osteoporotic drugs are available for treatment of osteoporosis and for preventing osteoporosis complications especially fractures. Most of the current anti-osteoporotic drugs are administered orally or parenterally to target the osteoporosis-affected bones. However, bone is a peripheral organ with limited blood supply. Therefore, the drugs delivered are exposed to various physicochemical and biological factors which affect the bioavailability of the drugs. In preclinical research, the dose of a potential anti-osteoporotic agent used in animal model may be too high for human application when administered via the conventional route of administration. The current anti-osteoporotic drugs need to be administered at higher doses to account for pharmacological interactions. However, this will expose the patients to adverse effects such as the cancer risks of postmenopausal women who took estrogen replacement therapy. There is also problem with patient compliance as anti-osteoporotic drugs may have to be taken for prolonged duration. The current deliveries of drugs need to be improved to overcome these problems. This review discussed several potential drug delivery systems which are able to contain the anti-osteoporosis drugs and release them slowly to the targeted bone. Among them are various carriers, polymers and microsponges, which may not only increase drug efficacy but also reduce adverse effects. The delivery systems allow the drugs to be administered locally at the targeted bone for longer duration, therefore reducing drug frequency and improving patient's compliance. It is hoped that these delivery systems may be applicable for the treatment of osteoporosis in the future to keep tab of the rising osteoporotic fracture incidence.

Micro-CT Assessments of Potential Anti-Osteoporotic Agents

Bone quality assessment is important in assessments of potential agents for the prevention and treatment of osteoporosis. Bone density, microarchitecture and strength are important determinants in osteoporotic study which are widely studied using Dual-Energy X-ray Absorptiometry (DXA), histomorphometry and radiological imaging techniques. In recent years, high resolution micro-CT has become feasible for in vitro or in vivo evaluation of bone architecture. Three-dimensional images of micro-CT reflected high correlations with the conventional histomorphometry and DXA. In comparison to other imaging techniques, micro-CT is the most effective tool in detecting early bone changes for fracture prediction and assessments of potential anti-osteoporotic agents. It is crucial to define an ideal setting with safe radiation doses and appropriate methods for image reconstruction and segmentation to obtain high resolution images. Micro-CT evaluation provides a better insight of bone structure as well as non-metric parameters such as connectivity density, structural model index (SMI) and degree of anisotropy (DA). This non- invasive imaging technique is also equipped with finite element analysis for evaluation of bone biomechanical strength. Micro-CT allows a compressive understanding of the relationships between bone density, microarchitecture and strength which is fundamental to development of pharmacological interventions.

Synthesis of Aminoalkoxy Substituted 4,5-Diphenylisoxazole Derivatives as Potential Anti-osteoporotic Agents

Certain 4,5-diarylisoxazole derivatives have been found to possess broad biological effects, including antiinflammatory and anticancer activities. Recently, we have reported preparation of certain isoflavone derivatives and investigated for their anti-osteoporotic and antiproliferative activities in a detailed SAR study. The present report describes the conversion of isoflavones into novel 4,5-diphenylisoxazole derivatives by the treatment with NH2OH. Alkylation followed by amination of these 4,5-diphenylisoxazoles gave the desired aminoalkoxy substituted 4,5-diphenylisoxazole derivatives. These compounds were evaluated in vitro for the osteogenic differentiation and quantification of mineralization. Although 5-isopropoxy-2-[4-(4-methoxyphenyl)isoxazol-5-yl]phenol (3) exhibited approximately 2.8-fold more activity than the positive Ipriflavone in the promotion of osteoblast activity (277% mineralization), the low cell viability (6%) and high cytotoxicity (68%) prompted us to further pursue more suitable candidates. A series of aminoalkyl side chains were introduced with aims to decrease cytotoxicity. Among them, 5-{4-isopropoxy-2-[4-(pyrrolidin-1-yl)butoxy]phenyl}-4-(4- methoxyphenyl)isoxazole (7a) exhibited approximately 2-fold more activity than the positive Ipriflavone in the promotion of osteoblast activity (194% mineralization) with comparable cell viability (71% v.s. 77%). Compound 7a was non cytotoxic against hADSCs and therefore, was selected as a lead for further structural optimization.

Effects of Tinospora cordifolia (Menispermaceae) on the proliferation, osteogenic differentiation and mineralization of osteoblast model systems in vitro

Ethnopharmacological relevanceAncient Indian ayurvedic literature prescribes Tinospora cordifolia as a remedy to rheumatoid arthritis, inflammatory and allied diseases of musculo skeletal system. AimTo investigate the effects of the alcoholic extract of Tinospora cordifolia (TC) on the proliferation, differentiation and mineralization of bone like matrix on osteoblast model systems in vitro and hence its possible use as a potential anti-osteoporotic agent. Materials and methodsTwo in vitro osteoblast model systems were used in the study viz., human osteoblast-like cells MG-63 and primary osteoblast cells isolated from femur of rats. Cell growth and viability was assessed by standard colorimetric assays like MTT assay. The cell differentiation into osteoblastic lineage was evaluated by the activities of bone marker alkaline phosphatase. The effect of the extract on matrix mineralization was assessed by alizarin red-s staining and Von kossa staining. Cell morphology was studied by phase contrast microscopy and light microscopy (Giemsa/crystal violet staining). ResultsResults indicate that the alcoholic extract of TC at a dosage of 25μg/ml stimulated the growth of osteoblasts, increased the differentiation of cells into osteoblastic lineage and increased the mineralization of bone like matrix on both the osteoblast model systems used in the study. Cell morphology studies clearly indicated the increase in cell numbers and absence of adverse change in the cell morphology on treatment with the extract. ConclusionTC extract has a potential influence on osteogenesis and hence its use could be explored as a potential anti-osteoporotic agent.

Potential antiosteoporotic agents from plants: a comprehensive review.

Osteoporosis is a major health hazard and is a disease of old age; it is a silent epidemic affecting more than 200 million people worldwide in recent years. Based on a large number of chemical and pharmacological research many plants and their compounds have been shown to possess antiosteoporosis activity. This paper reviews the medicinal plants displaying antiosteoporosis properties including their origin, active constituents, and pharmacological data. The plants reported here are the ones which are commonly used in traditional medical systems and have demonstrated clinical effectiveness against osteoporosis. Although many plants have the potential to prevent and treat osteoporosis, so far, only a fraction of these plants have been thoroughly investigated for their physiological and pharmacological properties including their mechanism of action. An attempt should be made to highlight plant species with possible antiosteoporosis properties and they should be investigated further to help with future drug development for treating this disease.

Bafilomycin K, a new antifungal macrolide from Streptomyces flavotricini Y12-26

Because of the special living environment, marine-derived actinomycetes, especially the genus Streptomyces, possess distinct and complex metabolic capabilities, resulting in wide diversity of their secondary metabolites in chemical structures and biological activities.1 Among them, many valuable lead compounds were obtained for discovery of new antibiotics.2, 3, 4 Bafilomycins are a family of polyene macrolides containing a 16-member lactone ring. Thirteen bafilomycin antibiotics have been isolated, including bafilomycins A1, A2, B1, B2, C1 and C2 from Streptomyces griseus sp. sulphurus (TU 1922),5 bafilomycins D and E from S. griseus TU 25996 and bafilomycins F–J from Streptomyces spp.7 Among them, bafilomycins D and E contain the ring-opened side chain different from other bafilomycins. Bafilomycins have antibacterial, antifungal, antineoplastic and immunosuppressive activities.5 Some bafilomycins are specific inhibitors of vacuolar-type H+-ATPase (V-ATPase),8, 9, 10, 11 in which bafilomycin A1 is the most used. Being a specific inhibitor of V-ATPase, bafilomycin A1 can prevent the re-acidification of synaptic vesicles once they have undergone exocytosis. In addition, bafilomycin A1 has antimalarial activity.12 Bafilomycins B1 and C1 have been mentioned as potential antiosteoporotic agents in treating bone lytic diseases.

Patent Evaluation: Trifluoromethylbenzylphosphonates as potential anti-osteoporotic agents

Patent Evaluation: Trifluoromethylbenzylphosphonates as potential anti-osteoporotic agents