Curcumin (diferuloylmethane) inhibits receptor activator of NF-kappa B ligand-induced NF-kappa B activation in osteoclast precursors and suppresses osteoclastogenesis

Olive polyphenol hydroxytyrosol prevents bone loss

Polyphenols reportedly exert physiological effects against diseases such as cancer, arteriosclerosis, hyperlipidemia and osteoporosis. The present study was designed to evaluate the effects of oleuropein, hydroxytyrosol and tyrosol, the major polyphenols in olives, on bone formation using cultured osteoblasts and osteoclasts, and on bone loss in ovariectomized mice. No polyphenols markedly affected the proliferation of osteoblastic MC3T3-E1 cells at concentrations up to 10μM. Oleuropein and hydroxytyrosol at 10 to 100μM had no effect on the production of type I collagen and the activity of alkaline phosphatase in MC3T3-E1 cells, but stimulated the deposition of calcium in a dose-dependent manner. In contrast, oleuropein at 10 to 100μM and hydroxytyrosol at 50 to 100μM inhibited the formation of multinucleated osteoclasts in a dose-dependent manner. Furthermore, both compounds suppressed the bone loss of trabecular bone in femurs of ovariectomized mice (6-week-old BALB/c female mice), while hydroxytyrosol attenuated H(2)O(2) levels in MC3T3-E1 cells. Our findings indicate that the olive polyphenols oleuropein and hydroxytyrosol may have critical effects on the formation and maintenance of bone, and can be used as effective remedies in the treatment of osteoporosis symptoms.

Butein, a tetrahydroxychalcone, suppresses cancer-induced osteoclastogenesis through inhibition of receptor activator of nuclear factor-kappaB ligand signaling

Osteoclastogenesis is associated with aging and various age-related inflammatory chronic diseases, including cancer. Receptor activator of nuclear factor-kappaB (NF-κB) ligand (RANKL), a member of the tumor necrosis factor superfamily, has been implicated as a major mediator of bone resorption, suggesting that agents that can suppress RANKL signaling might inhibit osteoclastogenesis, a process closely linked to bone resorption. We therefore investigated whether butein, a tetrahydroxychalcone, could inhibit RANKL signaling and suppress osteoclastogenesis induced by RANKL or tumor cells. We found that human multiple myeloma cells (MM.1S and U266), breast tumor cells (MDA-MB-231) and prostate tumor cells (PC-3) induced differentiation of macrophages to osteoclasts, as indicated by tartrate-resistant acid phosphatase (TRAP)-positive cells, and that butein suppressed this process. The chalcone also suppressed the expression of RANKL by the tumor cells. We further found that butein suppressed RANKL-induced NF-κB activation and that this suppression correlated with the inhibition of IκBα kinase and suppression of phosphorylation and degradation of IκBα, an inhibitor of NF-κB. Finally, butein also suppressed the RANKL-induced differentiation of macrophages to osteoclasts in a dose-dependent and time-dependent manner. Collectively, our results indicate that butein suppresses the osteoclastogenesis induced by tumor cells and by RANKL, by suppression of the NF-κB activation pathway.

Maslinic acid suppresses osteoclastogenesis and prevents ovariectomy-induced bone loss by regulating RANKL-mediated NF-κB and MAPK signaling pathways

Activation of NF-κB and MAPK/activator protein 1 (AP-1) signaling pathways by receptor activator NF-κB ligand (RANKL) is essential for osteoclast activity. Targeting NF-κB and MAPK/AP-1 signaling to modulate osteoclast activity has been a promising strategy for osteoclast-related diseases. In this study we examined the effects of maslinic acid (MA), a pentacyclic triterpene acid that is widely present in dietary plants, on RANKL-induced osteoclastogenesis, osteoclast function, and signaling pathways by in vitro and in vivo assay systems. In mouse bone marrow monocytes (BMMs) and RAW264.7 cells, MA inhibited RANKL-induced osteoclastogenesis in a dose-dependent manner within nongrowth inhibitory concentration, and MA decreased osteoclastogenesis-related marker gene expression, including TRACP, MMP9, c-Src, CTR, and cathepsin K. Specifically, MA suppressed osteoclastogenesis and actin ring formation at early stage. In ovariectomized mice, administration of MA prevented ovariectomy-induced bone loss by inhibiting osteoclast activity. At molecular levels, MA abrogated the phosphorylation of MAPKs and AP-1 activity, inhibited the IκBα phosphorylation and degradation, blocked NF-κB/p65 phosphorylation, nuclear translocation, and DNA-binding activity by downregulating RANK expression and blocking RANK interaction with TRAF6. Together our data demonstrate that MA suppresses RANKL-induced osteoclastogenesis through NF-κB and MAPK/AP-1 signaling pathways and that MA is a promising agent in the treatment of osteoclast-related diseases such as osteoporosis.

Potent anti-inflammatory effects of systemically administered curcumin modulate periodontal disease in vivo

BACKGROUND AND OBJECTIVE

Curcumin is a plant-derived dietary spice with various biological activities, including anticarcinogenic and anti-inflammatory effects. Its therapeutic applications have been studied in a variety of conditions, including rheumatoid arthritis, colon cancer and depression, but no studies have evaluated the effects of curcumin on periodontal disease in vivo.

MATERIAL AND METHODS

Experimental periodontal disease was induced in rats by placing cotton ligatures around both lower first molars. Curcumin was given to the rats by the intragastric route daily at two dosages (30 and 100 mg/kg) for 15 d. Control animals received ligatures but only the corn oil vehicle by gavage, and no treatment-negative control animals were included. Bone resorption was assessed by micro-computed tomography, and the inflammatory status was evaluated by stereometric analysis. Both RT-qPCR and ELISA were used to determine the expression of interleukin-6, tumor necrosis factor-α and prostaglandin E(2) synthase in the gingival tissues. Modulation of p38 MAPK and nuclear factor-κB activation were assessed by western blotting.

RESULTS

Bone resorption was effectively induced in the experimental period, but it was not affected by either dose of curcumin. Curcumin effectively inhibited cytokine gene expression at both the mRNA and the protein level and produced a dose-dependent inhibition of the activation of nuclear factor-κB in the gingival tissues. Activation of p38 MAPK was not inhibited by curcumin. Curcumin-treated animals also presented a marked reduction of the inflammatory cell infiltrate and increased collagen content and fibroblastic cell numbers.

CONCLUSION

Curcumin did not prevent alveolar bone resorption, but its potent anti-inflammatory effect suggests that it may have a therapeutic potential in periodontal diseases.

Curcumin improves bone microarchitecture and enhances mineral density in APP/PS1 transgenic mice

Alzheimer's disease and osteoporosis are often observed to co-occur in clinical practice. The present study aimed to evaluate the bone microarchitecture and bone mineral density (BMD) of the proximal tibia in APP/PS1 transgenic mice by micro-computed tomography (micro-CT), and to search for evidence that curcumin can be used to reduce bone mineral losses and treat osteoporosis after senile dementia in these transgenic mice. Three-month-old female mice were divided into the following groups (n=9 per group): wild-type mice (WT group); APP/PS1 transgenic mice (APP group); and APP/PS1 transgenic mice with curcumin treatment (APP+Cur group). Between 9 and 12 months of age, the APP+Cur group were administered curcumin orally (600ppm). CT scans of the proximal tibia were taken at 6, 9 and 12 months. At 6 months, there were little differences in the structural parameters. At 9 months, the APP groups displayed loss of bone volume ratio (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N) and connectivity density (Conn.D) and increases in trabecular separation (Tb.Sp) and geometric degree of anisotropy (DA) (P<0.05 or P<0.01), with significant changes in the BMD parameters. At 12 months, curcumin treatment led to constant increases in the trabecular bone mass of the metaphysis and clearly improved the BMD. By the same time, we measured the TNF-α and IL-6 in the serum among the different groups at 6, 9 and 12 months by enzyme-linked immunoassay(ELISA). These results suggest that APP/PS1 transgenic mice are susceptible to osteoporosis, and that curcumin can prevent further deterioration of the bone structure and produce beneficial changes in bone turnover. The change of inflammation cytokine, including TNF-α and IL-6, may play an important role in the mechanisms of action of curcumin, but the detail mechanism remains unknown.

Amorphigenin inhibits Osteoclast differentiation by suppressing c-Fos and nuclear factor of activated T cells

Among the several rotenoids, amorphigenin is isolated from the leaves of Amopha Fruticosa and it is known that has anti-proliferative effects and anti-cnacer effects in many cell types. The main aim of this study was to investigate the effects of amorphigenin on osteoclast differentiation in vitro and on LPS treated inflammatory bone loss model in vivo. We show here that amorphigenin inhibited RANKL-induced osteoclast differentiation from bone marrow macrophages in a dose dependent manner without cellular toxicity. Anti-osteoclastogenic properties of amorphigenin were based on a down-regulation of c-fos and NFATc1. Amorphigenin markedly inhibited RANKL-induced p38 and NF-κB pathways, but other pathways were not affected. Micro-CT analysis of the femurs showed that amorphigenin protected the LPS-induced bone loss. We concluded that amorphigenin can prevent inflammation-induced bone loss. Thus we expect that amorphigenin could be a treatment option for bone erosion caused by inflammation.

Protection of trabecular bone in ovariectomized rats by turmeric (Curcuma longa L.) is dependent on extract composition

Extracts prepared from turmeric (Curcuma longa L., [Zingiberaceae]) containing bioactive phenolic curcuminoids were evaluated for bone-protective effects in a hypogonadal rat model of postmenopausal osteoporosis. Three-month female Sprague-Dawley rats were ovariectomized (OVX) and treated with a chemically complex turmeric fraction (41% curcuminoids by weight) or a curcuminoid-enriched turmeric fraction (94% curcuminoids by weight), both dosed at 60 mg/kg 3x per week, or vehicle alone. Effects of two months of treatment on OVX-induced bone loss were followed prospectively by serial assessment of bone mineral density (BMD) of the distal femur using dual-energy X-ray absorptiometry (DXA), while treatment effects on trabecular bone microarchitecture were assessed at two months by microcomputerized tomography (microCT). Chemically complex turmeric did not prevent bone loss, however, the curcuminoid-enriched turmeric prevented up to 50% of OVX-induced loss of trabecular bone and also preserved the number and connectedness of the strut-like trabeculae. These results suggest that turmeric may have bone-protective effects but that extract composition is a critical factor.

Inhibition of osteoclast differentiation and bone resorption by rotenone, through down-regulation of RANKL-induced c-Fos and NFATc1 expression

Osteoclasts are responsible for bone erosion in diseases as diverse as osteoporosis, periodontitis, and rheumatoid arthritis. Natural plant-derived products have received recent attention as potential therapeutic and preventative drugs in human disease. The effect of rotenone in RANKL-induced osteoclast differentiation was examined in this study. Rotenone inhibited RANKL-mediated osteoclast differentiation in bone marrow macrophages (BMMs) in a dose-dependent manner without any evidence of cytotoxicity. The mRNA expression of c-Fos, NFATc1, TRAP, and OSCAR in RANKL-treated BMMs was inhibited by rotenone treatment. Rotenone strongly inhibited p38 and ERK phosphorylation and I-kappaB degradation in RANKL-stimulated BMMs, and did not inhibit JNK phosphorylation. Further, RANKL-induced c-Fos and NFATc1 protein expression was suppressed by rotenone. Rotenone additionally inhibited the bone resorptive activity of differentiated osteoclasts. A lipopolysaccharide (LPS)-induced bone erosion study was also performed to assess the effects of rotenone in vivo. Mice treated with rotenone demonstrated marked attenuation of bone erosion based on Micro CT and histologic analysis of femurs. These results collectively suggested that rotenone demonstrated inhibitory effects on osteoclast differentiation in vitro and suppressed inflammatory bone loss in vivo. Rotenone may therefore serve as a useful drug in the prevention of bone loss.

Fluorocurcumins as cyclooxygenase-2 inhibitor: molecular docking, pharmacokinetics and tissue distribution in mice

PURPOSE

The purpose of the current study was to assess the effect of newly synthesized Curcumin analogs on COX-2 protein by molecular docking studies and by assessments of the effect of one such analog (CDF) on nuclear factor NF-kappaB and PGE(2). In addition, we have determined the pharmacokinetics and tissue distribution of CDF in mice compared to Curcumin.

METHODS

Molecular docking on COX-2 protein was assessed by standard computer modeling studies. PGE(2) assay in conditioned media was done utilizing high sensitivity immunoassay kit following manufacturer's instructions, while NF-kappaB was done by routine EMSA. Serum pharmacokinetics and tissue distribution studies were carried out using the validated high-performance liquid chromatography with tandem mass spectrometry (LC-MS/MS) methods.

RESULTS

The molecular docking showed that fluorocurcumin analogs do not introduce any major steric changes compared to the parent Curcumin molecule, which was consistent with down-regulation of NF-kappaB and reduced PGE(2) levels in cells treated with CDF. Pharmacokinetic parameters revealed that CDF had better retention and bioavailability and that the concentration of CDF in the pancreas tissue was 10-fold higher compared to Curcumin.

CONCLUSION

Our observations clearly suggest that the bioavailability of CDF is much superior compared to Curcumin, suggesting that CDF would be clinically useful.

Curcumin suppresses increased bone resorption by inhibiting osteoclastogenesis in rats with streptozotocin-induced diabetes

Curcumin is a potent inhibitor of the transcription factor activator protein-1 which plays an essential role in osteoclastogenesis. However, the effects of curcumin on bone metabolism have not been clarified in vivo. We reported herein the inhibitory effects of curcumin on the stimulated osteoclastic activity in insulin-dependent diabetes mellitus using rats with streptozotocin-induced diabetes. A dietary supplement of curcumin reversed the increase in levels of activity and mRNA of tartrate-resistant acid phosphatase (TRAP) and cathepsin K to control values. A histochemical analysis showed that the increase in TRAP-positive cells in the distal femur of the diabetic rats was reduced to the control level by the supplement. These results suggested that curcumin reduced diabetes-stimulated bone resorptive activity and the number of osteoclasts. When bone marrow cells were cultured with macrophage colony stimulating factor and receptor activator NF-kappaB ligand (RANKL), the increased activity to form TRAP-positive multinucleated cells and the increased levels of mRNA and protein of c-fos and c-jun in the cultured cells from diabetic rats decreased to control levels in the curcumin-supplemented rats. Similarly, the increased expression of c-fos and c-jun in the distal femur of the diabetic rats was significantly reduced by the supplement. These results suggested that curcumin suppressed the increased bone resorptive activity through the prevention of osteoclastogenesis associated with inhibition of the expression of c-fos and c-jun in the diabetic rats.

Curcumin, a potential inhibitor of up-regulation of TNF-alpha and IL-6 induced by palmitate in 3T3-L1 adipocytes through NF-kappaB and JNK pathway

OBJECTIVE

To investigate the attenuating effect of curcumin, an anti-inflammatory compound derived from dietary spice turmeric (Curcuma longa) on the pro-inflammatory insulin-resistant state in 3T3-L1 adipocytes.

METHODS

Glucose uptake rate was determined with the [3H] 2-deoxyglucose uptake method. Expressions of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) were measured by quantitative RT-PCR analysis and ELISA. Nuclear transcription factor kappaB p65 (NF-kappa p65) and mitogen-activated protein kinase (MAPKs) were detected by Western blot assay.

RESULTS

The basal glucose uptake was not altered, and curcumin increased the insulin-stimulated glucose uptake in 3T3-L1 cells. Curcumin suppressed the transcription and secretion of TNF-alpha and IL-6 induced by palmitate in a concentration-dependent manner. Palmitate induced nuclear translocation of NF-kappaB. The activities of Jun NH2-terminal kinase (JNK), extracellular signal-regulated kinase1/2 (ERK1/2) and p38MAPK decreased in the presence of curcumin. Moreover, pretreatment with SP600125 (inhibitor of JNK) instead of PD98059 or SB203580 (inhibitor of ERK1/2 or p38MAPK, respectively) decreased the up-regulation of TNF-alpha induced by palmitate.

CONCLUSION

Curcumin reverses palmitate-induced insulin resistance state in 3T3-L1 adipocytes through the NF-kappaB and JNK pathway.

(-)-Epigallocatechin gallate inhibition of osteoclastic differentiation via NF-kappaB

People who regularly drink tea have been found to have a higher bone mineral density (BMD) and to be at less risk of hip fractures than those who do not drink it. Green tea catechins such as (-)-epigallocatechin gallate (EGCG) have been reported to increase osteogenic functioning in mesenchymal stem cells. However, its effect on osteoclastogenesis remains unclear. In this study, we investigated the effect of EGCG on RANKL-activation osteoclastogenesis and NF-kappaB in RAW 264.7, a murine preosteoclast cell line. EGCG (10-100 microM) significantly suppressed the RANKL-induced differentiation of osteoclasts and the formation of pits in murine RAW 264.7 cells and bone marrow macrophages (BMMs). EGCG appeared to target osteoclastic differentiation at an early stage but had no cytotoxic effect on osteoclast precursors. In addition, it significantly inhibited RANKL-induced NF-kappaB transcriptional activity and nuclear translocation. We conclude that EGCG inhibits osteoclastogenesis through its activation of NF-kappaB.

Pharmacological basis for the role of curcumin in chronic diseases: an age-old spice with modern targets

Curcumin (diferuloylmethane), a yellow pigment in the spice turmeric (also called curry powder), has been used for centuries as a treatment for inflammatory diseases. Extensive research within the past two decades has shown that curcumin mediates its anti-inflammatory effects through the downregulation of inflammatory transcription factors (such as nuclear factor kappaB), enzymes (such as cyclooxygenase 2 and 5 lipoxygenase) and cytokines (such as tumor necrosis factor, interleukin 1 and interleukin 6). Because of the crucial role of inflammation in most chronic diseases, the potential of curcumin has been examined in neoplastic, neurological, cardiovascular, pulmonary and metabolic diseases. The pharmacodynamics and pharmacokinetics of curcumin have been examined in animals and in humans. Various pharmacological aspects of curcumin in vitro and in vivo are discussed in detail here.

The ovariectomized, mature rat model of postmenopausal osteoporosis: an assessment of the bone sparing effects of curcumin

Identification of natural health products that might benefit skeletal health could reduce the negative impact of osteoporotic bone fractures upon society. The objectives of this study were to evaluate an animal model of postmenopausal osteoporosis and to search for evidence that curcumin reduces bone mineral losses in a dose-dependent manner when endogenous estrogen levels are reduced. Bone mineral density was measured at the spine, femur and whole body before and at 2, 4 and 6 months after ovariectomy in each of 40 mature rats. Serum osteocalcin and C-telopeptide were measured as indicators of bone formation and resorption rates. Femoral compressive strength was measured at 6 months. Ovariectomy alone resulted in loss of mineral from the spine (p<0.005) and an increase in osteocalcin levels (p<0.05). At the same time, there was an increase in energy to fracture (p<0.01) due to an increased bone size. When ovariectomized animals were given etidronate there was no loss of mineral from the spine, the size of the femur increased (p<0.005), C-telopeptide levels were reduced (p<0.001) and femoral compressive strength increased (p<0.025). Administration of curcumin to ovariectomized animals resulted in changes that were intermediate between those produced by etidronate and by ovariectomy alone. The increase in femur size produced by the highest dose of curcumin was statistically significant (p< 0.01) and curcumin administration resulted in a significant, dose dependent, increase in energy to fracture. Curcumin produces beneficial changes in bone turnover and increases in bone strength using the ovariectomized mature rat model of postmenopausal osteoporosis.

Baicalein inhibits osteoclast differentiation and induces mature osteoclast apoptosis

In bone remodeling, an imbalance caused by increased bone resorption over bone formation leads to adult skeletal diseases such as osteoporosis. Therefore, the development of anti-resorptive agents has still gained more interest. In this study, using cell-based assay systems in RAW264.7 murine macrophage cells, we found that baicalein significantly inhibited the receptor activator of NF-kappaB ligand (RANKL)-induced tartrate-resistance acid phosphatase (TRAP) activity and the formation of multinucleated osteoclasts in a dose-dependent manner. Interestingly, baicalein inhibited RANKL-induced activation of signaling molecules (Akt, ERK/MAP kinase and NF-kappaB) and mRNA expression of osteoclast-associated genes (TRAP, matrix metalloproteinase 9 and c-Src) and another transcription factors (c-Fos, Fra-2 and NFATc1). In addition, baicalein inhibited the bone resorptive activity of mature osteoclasts by inducing apoptosis. The inhibitory effects of baicalein on the formation of mouse bone marrow macrophage-derived osteoclasts and their bone resorptive activity were also observed. In conclusion, although further studies are needed to determine its biological efficacy and precise mechanism in bone, the present results demonstrated that baicalein has a potential to inhibit osteoclast differentiation and induce mature osteoclast apoptosis.

Dietary curcumin significantly improves obesity-associated inflammation and diabetes in mouse models of diabesity

Obesity is a major risk factor for the development of type 2 diabetes, and both conditions are now recognized to possess significant inflammatory components underlying their pathophysiologies. We tested the hypothesis that the plant polyphenolic compound curcumin, which is known to exert potent antiinflammatory and antioxidant effects, would ameliorate diabetes and inflammation in murine models of insulin-resistant obesity. We found that dietary curcumin admixture ameliorated diabetes in high-fat diet-induced obese and leptin-deficient ob/ob male C57BL/6J mice as determined by glucose and insulin tolerance testing and hemoglobin A1c percentages. Curcumin treatment also significantly reduced macrophage infiltration of white adipose tissue, increased adipose tissue adiponectin production, and decreased hepatic nuclear factor-kappaB activity, hepatomegaly, and markers of hepatic inflammation. We therefore conclude that orally ingested curcumin reverses many of the inflammatory and metabolic derangements associated with obesity and improves glycemic control in mouse models of type 2 diabetes. This or related compounds warrant further investigation as novel adjunctive therapies for type 2 diabetes in man.

Mending the bones with natural products

In this issue, Qiu and colleagues [1] demonstrate in vitro and in vivo activity of a triterpene glycoside from black cohosh. The isolated compound acts as a suppressor of osteoclastogenesis, targeting specifically RANKL, a member of the TNF superfamily.

Anti-inflammatory effect of curcumin involves downregulation of MMP-9 in blood mononuclear cells

Curcumin (1, 7-bis (4-hydroxyl-3-methoxyphenyl)-1, 6 heptadiene-3, 5-dione) is a potent natural anti oxidant and anti-inflammatory agent, which mediates its effects mainly by inhibiting the activity of enzymes like cyclooxygenase, lipooxygenases and phospholipase A2. Here we examined the possibility of curcumin affecting the production of matrix metalloproteinases (MMPs) by peripheral blood mononuclear cells (PBMCs), which play an important role in inflammation. Zymographic analysis and ELISA showed that curcumin significantly inhibited the activity and level of MMPs produced by PBMCs isolated from human and inflammation-induced rabbit in a concentration dependent manner. The administration of curcumin to inflammation-induced rabbits also caused downregulation of MMP-9. Kinetic analysis showed that the effect of curcumin was a delayed one indicating inhibition of de novo protein synthesis. RT-PCR and immunoblot analysis showed inhibition of the production of MMP-9 mRNA and protein respectively by human PBMCs, which were activated in vitro by Artocarpus Lakoocha agglutinin (ALA) lectin. EMSA and super shift showed activation of classical NFkappaB in in vitro activated PBMCs and treatment with curcumin inhibited activation of NFkappaB. Immunoblot analysis suggested that ALA-induced activation of NFkappaB leading to the upregulation of MMP-9 was due to the degradation of IkappaB-alpha. Curcumin inhibited the degradation of IkappaB-alpha, which inhibited the ALA mediated activation of NFkappaB and upregulation of MMP-9. These results indicated that anti-inflammatory effect of curcumin also involves inhibition of the production of MMP-9 in PBMCs.

CURCUMIN: THE INDIAN SOLID GOLD

Turmeric, derived from the plant Curcuma longa, is a gold-colored spice commonly used in the Indian subcontinent, not only for health care but also for the preservation of food and as a yellow dye for textiles. Curcumin, which gives the yellow color to turmeric, was first isolated almost two centuries ago, and its structure as diferuloylmethane was determined in 1910. Since the time of Ayurveda (1900 Bc) numerous therapeutic activities have been assigned to turmeric for a wide variety of diseases and conditions, including those of the skin, pulmonary, and gastrointestinal systems, aches, pains, wounds, sprains, and liver disorders. Extensive research within the last half century has proven that most of these activities, once associated with turmeric, are due to curcumin. Curcumin has been shown to exhibit antioxidant, anti-inflammatory, antiviral, antibacterial, antifungal, and anticancer activities and thus has a potential against various malignant diseases, diabetes, allergies, arthritis, Alzheimer's disease, and other chronic illnesses. These effects are mediated through the regulation of various transcription factors, growth factors, inflammatory cytokines, protein kinases, and other enzymes. Curcumin exhibits activities similar to recently discovered tumor necrosis factor blockers (e.g., HUMIRA, REMICADE, and ENBREL), a vascular endothelial cell growth factor blocker (e.g., AVASTIN), human epidermal growth factor receptor blockers (e.g., ERBITUX, ERLOTINIB, and GEFTINIB), and a HER2 blocker (e.g., HERCEPTIN). Considering the recent scientific bandwagon that multitargeted therapy is better than monotargeted therapy for most diseases, curcumin can be considered an ideal "Spice for Life".

Zyflamend, a polyherbal preparation, inhibits invasion, suppresses osteoclastogenesis, and potentiates apoptosis through down-regulation of NF-kappa B activation and NF-kappa B-regulated gene products

Zyflamend, a polyherbal preparation, was designed based on constituents that exhibit antiproliferative, antiinflammatory, antioxidant, antiangiogenic, and apoptotic activities through a mechanism that is not well defined. Because the nuclear factor (NF)-kappaB has been shown to regulate proliferation, invasion, and metastasis of tumor cells, we postulated that Zyflamend modulates the activity of NF-kappa B. To test this hypothesis, we examined the effect of this preparation on NF-kappaB and NF-kappaB-regulated gene products. We found that Zyflamend inhibited receptor activator of NF-kappa B ligand-induced osteoclastogenesis, suppressed tumor necrosis factor (TNF)-induced invasion, and potentiated the cytotoxicity induced by TNF and chemotherapeutic agents, all of which are known to require NF-kappa B activation. Zyflamend suppressed NF-kappa B activation induced by both TNF and cigarette smoke condensate. The expression of NF-kappa B-regulated gene products involved in antiapoptosis (inhibitor-of-apoptosis protein 1/2, Bcl-2, Bcl-xL, FADD-like interleukin-1betaconverting enzyme/caspase-8 inhibitory protein, TNF receptor-associated factor-1, and survivin) and angiogenesis (vascular endothelial growth factor, cyclooxygenase-2, intercellular adhesion molecule, and matrix metalloproteinase-9) was also down-regulated by Zyflamend. This correlated with potentiation of cell death induced by TNF and chemotherapeutic agents. Overall, our results indicate that Zyflamend suppresses osteoclastogenesis, inhibits invasion, and potentiates cytotoxicity through down-regulation of NF-kappa B activation and NF-kappa B-regulated gene products.

Curcumin induces G2/M cell cycle arrest in a p53-dependent manner and upregulates ING4 expression in human glioma

Gliomas are the most common and lethal primary tumors of the central nervous system (CNS). Despite current rigorous treatment protocols, effect of chemotherapy has failed to improve patient outcome significantly. Curcumin is a potent antioxidant that possesses both anti-inflammatory and anti-tumor activities, can suppress the initiation, promotion, and metastasis of different tumors. Its anti-tumor properties in various cancer models and negligible toxicity in normal cells make it a promising chemotherapeutic candidate. But the effect and the molecular mechanism of curcumin on gliomas are still recognized limitedly. The goal of the study is to elucidate the inhibitory effect and possible mechanisms of curcumin on glioma. After the treatment of curcumin, glioma cells U251 growth in vitro were significantly inhibited in a dose-dependent manner, and the low dose of curcumin induced G2/M cell cycle arrest. The high dose of curcumin not only enhanced G2/M cell cycle arrest, but also induced S phase of cell cycle arrest. But no obvious pre-G1 peak was observed at the different doses of curcumin. Genome DNA electrophoresis further confirmed that no DNA ladder was formed after the treatment of curcumin in U251 cells. Results of Western blot analysis demonstrated that ING4 expression was almost undetectable in U251 cells, but significantly up-regulated during cell cycle arrest induced by curcumin, and p53 expression was up-regulated followed by induction of p21 WAF-1/CIP-1 and ING4. The results demonstrate that curcumin exerts inhibitory action on glioma cell growth and proliferation via induction of cell cycle arrest instead of induction of apoptosis in a p53-dependent manner, and ING4 possibly is in part involved in the signal pathways.

Effects of flavonoid on calcium content in femoral tissue culture and parathyroid hormone-stimulated osteoclastogenesis in bone marrow culture in vitro

The effect of various flavonoids, which are present in food and plants, on bone calcium content and osteoclastogenesis were investigated to compare action of flavonoid on bone formation and bone resorption in vitro. Rat femoral-diaphyseal (cortical bone) and -metaphyseal (trabecular bone) tissues were cultured for 48 h in Dulbecco's modified Eagle's medium (high glucose) supplemented with antibiotics and bovine serum albumin. Amoung quercetin, myricetin, kaempferol, isorhamnetin, curcumin, hesperidin, or astaxanthin in the range of 10(-7)-10(-5)M, culture with quercetin (10(-6) or 10(-5)M) caused a significant increase in diaphyseal calcium content. Such an effect was not seen in other compounds. Mouse bone marrow cells were cultured for 7 days in the presence of parathyroid hormone (PTH; 10(-7)M), a bone-resorbing factor, in vitro. Culture with PTH caused a significant increase in osteoclast-like cell formation. This increase was significantly inhibited in the presence of quercetin, myricetin, kaempferol, isorhamnetin, or curcumin in the range of 10(-8)-10(-6)M. Such an effect was not seen in the case of hesperidin or astaxanthin. In addition, culture with PTH (10(-7)M) caused a significant decrease in diaphyseal calcium content. This decrease was completely prevented in the presence of quercetin, myricetin, kaempferal, or isorhamnetin of 10(-6)M. This study demonstrates that various flavonoids have a potent inhibitory effect on osteoclastogenesis and bone resorption rather than bone formation in vitro. Among various flavonoids, quercetin had a stimulatory effect on bone formation and an inhibitory effect on bone resorption in vitro.

Gossypin, a pentahydroxy glucosyl flavone, inhibits the transforming growth factor beta-activated kinase-1-mediated NF-kappaB activation pathway, leading to potentiation of apoptosis, suppression of invasion, and abrogation of osteoclastogenesis

Gossypin, a flavone originally isolated from Hibiscus vitifolius, has been shown to suppress angiogenesis, inflammation, and carcinogenesis. The mechanisms of these activities, however, are unknown. Because nuclear factor-kappaB (NF-kappaB) is associated with inflammation, carcinogenesis, hyperproliferation, invasion, and angiogenesis, we hypothesized that gossypin mediates its effects through modulation of NF-kappaB activation. In the present study, we demonstrate that gossypin (and not gossypetin, an aglycone analog) inhibited NF-kappaB activation induced by inflammatory stimuli and carcinogens. Constitutive NF-kappaB activation in tumor cells was also inhibited by this flavone. Inhibition of I kappa B alpha kinase by gossypin led to the suppression of I kappa B alpha phosphorylation and degradation, p65 nuclear translocation, and NF-kappaB-regulated gene expression. This, in turn, led to the down-regulation of gene products involved in cell survival (IAP2, XIAP, Bcl-2, Bcl-xL, survivin, and antiFas-associated death domain-like interleukin-1 beta-converting enzyme-inhibitory protein), proliferation (c-myc, cyclin D1, and cyclooxygenase-2), angiogenesis (vascular endothelial growth factor), and invasion (matrix metalloprotease-9). Suppression of these gene products by gossypin enhanced apoptosis induced by tumor necrosis factor and chemotherapeutic agents, suppressed tumor necrosis factor-induced cellular invasion, abrogated receptor activator of NF-kappaB ligand-induced osteoclastogenesis, and vascular endothelial growth factor-induced migration of human umbilical vein endothelial cells. Overall, our results demonstrate that gossypin inhibits the NF-kappaB activation pathway, which may explain its role in the suppression of inflammation, carcinogenesis, and angiogenesis.

Inhibitory effect of ribbon-type NF-kappaB decoy oligodeoxynucleotides on osteoclast induction and activity in vitro and in vivo

In this study we examined the effect of ribbon-type (circular-type) NF-κB decoy oligodeoxynucleotides (RNODN) on osteoclast induction and activity. We extracted bone marrow cells from the femurs of rats and incubated non-adherent cells with receptor activator of nuclear factor κB ligand (RANKL) and macrophage colony-stimulating factor (M-CSF). First, transfer efficiency into osteoclasts and their precursors, resistance to exonuclease, and binding activity of decoy to NF-κB were examined. Next, to examine the effect of RNODN on osteoclast induction and activity, osteoclast differentiation and pit formation assays were performed. RNODN were injected into the ankle joints of rats with collagen-induced arthritis. Joint destruction and osteoclast activity were examined by histological study. The resistance of RNODN to exonuclease and their binding activity on NF-κB were both greater than those of phosphorothionated NF-κB decoy oligodeoxynucleotides. The absolute number of multinucleate cells scoring positive for tartrate-resistant acid phosphatase was significantly decreased in the RNODN-treated group. The average calcified matrix resorbed area was significantly decreased in the RNODN-treated group. Histological study showed marked suppression of joint destruction and osteoclast activity by intra-articular injection of RNODN. These results suggest the inhibitory effect of RNODN on the induction and activity of osteoclasts. Direct intra-articular injection of RNODN into the joints may be an effective strategy for the treatment of arthritis.

Immune response modulation by curcumin in a latex allergy model

Background

There has been a worldwide increase in allergy and asthma over the last few decades, particularly in industrially developed nations. This resulted in a renewed interest to understand the pathogenesis of allergy in recent years. The progress made in the pathogenesis of allergic disease has led to the exploration of novel alternative therapies, which include herbal medicines as well. Curcumin, present in turmeric, a frequently used spice in Asia has been shown to have anti-allergic and inflammatory potential.

Methods

We used a murine model of latex allergy to investigate the role of curcumin as an immunomodulator. BALB/c mice were exposed to latex allergens and developed latex allergy with a Th2 type of immune response. These animals were treated with curcumin and the immunological and inflammatory responses were evaluated.

Results

Animals exposed to latex showed enhanced serum IgE, latex specific IgG₁, IL-4, IL-5, IL-13, eosinophils and inflammation in the lungs. Intragastric treatment of latex-sensitized mice with curcumin demonstrated a diminished Th2 response with a concurrent reduction in lung inflammation. Eosinophilia in curcumin-treated mice was markedly reduced, co-stimulatory molecule expression (CD80, CD86, and OX40L) on antigen-presenting cells was decreased, and expression of MMP-9, OAT, and TSLP genes was also attenuated.

Conclusion

These results suggest that curcumin has potential therapeutic value for controlling allergic responses resulting from exposure to allergens.

Dysregulation of the ubiquitin-proteasome system by curcumin suppresses coxsackievirus B3 replication

Curcumin (diferuloylmethane), a natural polyphenolic compound extracted from the spice turmeric, has been reported to have anti-inflammatory, antioxidant, and antiproliferative properties by modulating multiple cellular machineries. It inhibits several intracellular signaling pathways, including the mitogen-activated protein kinases (MAPKs), casein kinase II (CKII), and the COP9 signalosome (CSN), in various cell types. It has also been recently demonstrated that exposure to curcumin leads to the dysregulation of the ubiquitin-proteasome system (UPS). Coxsackievirus infection is associated with various diseases, including myocarditis and dilated cardiomyopathy. In searching for new antiviral agents against coxsackievirus, we found that treatment with curcumin significantly reduced viral RNA expression, protein synthesis, and virus titer and protected cells from virus-induced cytopathic effect and apoptosis. We further demonstrated that reduction of viral infection by curcumin was unlikely due to inhibition of CVB3 binding to its receptors or CVB3-induced activation of MAPKs. Moreover, gene silencing of CKII and Jab1, a component of CSN, by small interfering RNAs did not inhibit the replication of coxsackievirus, suggesting that the antiviral action of curcumin is independent of these pathways. Finally, we showed that curcumin treatment reduced both the 20S proteasome proteolytic activities and the cellular deubiquitinating activities, leading to increased accumulation of ubiquitinated proteins and decreased protein levels of free ubiquitin. We have recently demonstrated that the UPS-mediated protein degradation and/or modification plays a critical role in the regulation of coxsackievirus replication. Thus, our results suggest an important antiviral effect of curcumin wherein it potently inhibits coxsackievirus replication through dysregulation of the UPS.

Phenethyl isothiocyanate suppresses receptor activator of NF-kappaB ligand (RANKL)-induced osteoclastogenesis by blocking activation of ERK1/2 and p38 MAPK in RAW264.7 macrophages

Osteoclastogenesis is induced by differentiation of hemopoietic cells of monocyte-macrophage lineage into bone-resorbing osteoclasts. The process is initiated by receptor activator of NF-kappaB ligand (RANKL) and resultant activation of mitogen-activated protein kinases (MAPK), including extracellular signal-regulated kinase (ERK)1/2, as well as the NFkappaB pathway. Phenethyl isothiocyanate (PEITC), a phytochemical present in various cruciferous plants, has been shown to disrupt those signaling pathways in several cell types. In this study, we examined the efficacy of PEITC for suppressing RANKL-induced osteoclastogenesis in RAW264.7 murine macrophages and addressed the underlying molecular mechanisms. PEITC (2-10 microM) suppressed osteoclastogenesis in a concentration dependent manner, as detected by tartarate-resistant acid phosphatase (TRAP) activity and microscopic observations. RANKL-up-regulated extracellular signal-regulated kinase (ERK)1/2 and p38 mitogen-activated protein kinase (MAPK) activities were attenuated by PEITC, whereas c-Jun N-terminal kinase (JNK1/2) activation was increased. PEITC also abrogated the RANKL-induced degradation of IkappaB-alpha, a suppressive partner of nuclear factor kappaB (NFkappaB), thereby inhibiting transcription activity, as detected by a reporter assay. In addition, PEITC reduced the level of NFkappaB-dependent mRNA expression of nuclear factor of activated T cell (NFAT)c1, a master regulator of osteoclastogenesis. Our results indicate that PEITC is a promising agent for treatment of osteoclastogenesis with a reasonable action mechanism.

Natural products as alternative treatments for metabolic bone disorders and for maintenance of bone health

Bone metabolism involves a complex balance between the deposition of matrix and mineralization and resorption. There is now good evidence that dietary components and herbal products can influence these processes, particularly by inhibiting bone resorption, thus having beneficial effects on the skeleton. For example, it has been reported that a number of common vegetables, including onion, garlic and parsley, can inhibit bone resorption in ovariectomized rats. Essential oils derived from sage, rosemary, thyme and other herbs inhibit osteoclast activity in vitro and in vitro and leading to an increase in bone mineral density. Soya, a rich source of isoflavones, has shown promising results and epidemiological evidence to support a use in maintaining bone health, and various traditional herbal formulae in Chinese and Ayurvedic medicine also have demonstrable effects in pharmacological models of osteoporosis. Recently, cannabinoids have been described as having positive effects on osteoblast differentiation, and the presence of cannabinoid receptors in bone tissue indicates a more complex role in bone metabolism than previously thought. The first part of this review briefly discusses normal bone metabolism and disorders caused by its disruption, with particular reference to osteoporosis and current pharmacological treatments. The effects of natural products on bone and connective tissue are then discussed, to include items of diet, herbal extracts and food supplements, with evidence for their efficacy outlined.

Water extract of Cordyceps sinensis (WECS) inhibits the RANKL-induced osteoclast differentiation

It has been reported that Cordyceps sinensis, a traditional Chinese medicine, has various pharmacological effects. The aim of this study was to clarify the effect of water extract of Cordyceps sinensis (WECS) on osteoclast differentiation in vitro. In mouse bone marrow cells and monocyte/macrophage cell line RAW264.7, WECS dose-dependently inhibited the receptor activator of nuclear factor kappa B (NF-kappaB) ligand (RANKL)-induced osteoclast differentiation by tartrate-resistant acid phosphatase (TRAP) staining. In fact, cytotoxic effect was not observed in the RAW264.7 cells treated with WECS. Moreover, the mRNA expression of osteoclast related genes (calcitonin receptor, cathepsin K, matrix metalloprotease 9 and nuclear factor of activated T cells c1) was also inhibited by WECS. Investigation of inhibitory mechanism by using electrophoretic mobility shift assay (EMSA) and Western blot analysis revealed that WECS inhibited the activation of NF-kappaB through the prevention of IkappaBalpha phosphorylation. In conclusion, the present results demonstrate for the first time that WECS is a potent inhibitor of the RANKL-induced osteoclast differentiation through a mechanism involving the NF-kappaB pathway.

Efficacy and mechanism of action of turmeric supplements in the treatment of experimental arthritis

OBJECTIVE

Scientific evidence is lacking for the antiarthritic efficacy of turmeric dietary supplements that are being promoted for arthritis treatment. Therefore, we undertook studies to determine the antiarthritic efficacy and mechanism of action of a well-characterized turmeric extract using an animal model of rheumatoid arthritis (RA).

METHODS

The composition of commercial turmeric dietary supplements was determined by high-performance liquid chromatography. A curcuminoid-containing turmeric extract similar in composition to these supplements was isolated and administered intraperitoneally to female Lewis rats prior to or after the onset of streptococcal cell wall-induced arthritis. Efficacy in preventing joint swelling and destruction was determined clinically, histologically, and by measurement of bone mineral density. Mechanism of action was elucidated by analysis of turmeric's effect on articular transcription factor activation, microarray analysis of articular gene expression, and verification of the physiologic effects of alterations in gene expression.

RESULTS

A turmeric fraction depleted of essential oils profoundly inhibited joint inflammation and periarticular joint destruction in a dose-dependent manner. In vivo treatment prevented local activation of NF-kappaB and the subsequent expression of NF-kappaB-regulated genes mediating joint inflammation and destruction, including chemokines, cyclooxygenase 2, and RANKL. Consistent with these findings, inflammatory cell influx, joint levels of prostaglandin E(2), and periarticular osteoclast formation were inhibited by turmeric extract treatment.

CONCLUSION

These translational studies demonstrate in vivo efficacy and identify a mechanism of action for a well-characterized turmeric extract that supports further clinical evaluation of turmeric dietary supplements in the treatment of RA.

Toward a core nutraceutical program for cancer management

As previously suggested, it may be feasible to impede tumorevoked angiogenesis with a nutraceutical program composed of glycine, fish oil, epigallocatechin-3-gallate, selenium, and silymarin, complemented by a low-fat vegan diet, exercise training, and, if feasible, a salicylate and the drug tetrathiomolybdate. It is now proposed that the scope of this program be expanded to address additional common needs of cancer patients: blocking the process of metastasis; boosting the cytotoxic capacity of innate immune defenses (natural killer [NK] cells); preventing cachexia, thromboembolism, and tumor-induced osteolysis; and maintaining optimal micronutrient status. Modified citrus pectin, a galectin-3 antagonist, has impressive antimetastatic potential. Mushroombeta-glucans and probiotic lactobacilli can amplify NK activity via stimulatory effects on macrophages. Selenium, beta-carotene, and glutamine can also increase the number and/or cytotoxic activity of NK cells. Cachectic loss of muscle mass can be opposed by fish oil, glutamine, and beta-hydroxy-beta-methylbutyrate. Fish oil, policosanol, and vitamin D may have potential for control of osteolysis. High-dose aspirin or salicylates, by preventing NF-B activation, can be expected to aid prevention of metastasis and cachexia while down-regulating osteolysis, but their impacts on innate immune defenses will not be entirely favorable. A nutritional insurance formula crafted for the special needs of cancer patients can be included in this regimen. To minimize patient inconvenience, this complex core nutraceutical program could be configured as an oil product, a powder, and a capsule product, with the nutritional insurance formula provided in tablets. It would be of interest to test this program in nude mouse xenograft models.

Honokiol Potentiates Apoptosis, Suppresses Osteoclastogenesis, and Inhibits Invasion through Modulation of Nuclear Factor-κB Activation Pathway

Recent reports have indicated that honokiol can induce apoptosis, suppress tumor growth, and inhibit angiogenesis. In this report, we found that honokiol potentiated the apoptosis induced by tumor necrosis factor (TNF) and chemotherapeutic agents, suppressed TNF-induced tumor cell invasion, and inhibited RANKL-induced osteoclastogenesis, all of which are known to require nuclear factor-kappaB (NF-kappaB) activation. Honokiol suppressed NF-kappaB activation induced by a variety of inflammatory stimuli, and this suppression was not cell type specific. Further studies showed that honokiol blocked TNF-induced phosphorylation, ubiquitination, and degradation of IkappaBalpha through the inhibition of activation of IkappaBalpha kinase and of Akt. This led to suppression of the phosphorylation and nuclear translocation of p65 and NF-kappaB-dependent reporter gene expression. Magnolol, a honokiol isomer, was equally active. The expression of NF-kappaB-regulated gene products involved in antiapoptosis (IAP1, IAP2, Bcl-x(L), Bcl-2, cFLIP, TRAF1, and survivin), proliferation (cyclin D1, cyclooxygenase-2, and c-myc), invasion (matrix metalloproteinase-9 and intercellular adhesion molecule-1), and angiogenesis (vascular endothelial growth factor) were also down-regulated by honokiol. Honokiol also down-regulated NF-kappaB activation in in vivo mouse dorsal skin model. Thus, overall, our results indicate that NF-kappaB and NF-kappaB-regulated gene expression inhibited by honokiol enhances apoptosis and suppresses osteoclastogenesis and invasion.

NF-kappaB and the regulation of hematopoiesis

This review will focus on the role of nuclear factor kappaB (NF-kappaB) signaling in hematopoietic differentiation. We will also discuss several hematopoietic pathologies associated with deregulation of NF-kappaB and their potential therapies.

Guggulsterone inhibits osteoclastogenesis induced by receptor activator of nuclear factor-kappaB ligand and by tumor cells by suppressing nuclear factor-kappaB activation

Bone resorption is commonly associated with aging and with certain types of cancer, including multiple myeloma and breast cancer. What induces bone resorption is not fully understood, but the role of osteoclasts is well established. Recently, receptor activator of nuclear factor-kappaB (NF-kappaB) ligand (RANKL), a member of the tumor necrosis factor superfamily, was implicated as a major mediator of bone resorption, suggesting that agents that can suppress RANKL signaling have the potential to inhibit bone resorption or osteoclastogenesis. Guggulsterone [4,17(20)-pregnadiene-3,16-dione], isolated from the guggul tree Commiphora mukul and used to treat osteoarthritis and bone fractures, was recently shown to antagonize the farnesoid X receptor, decrease the expression of bile acid-activated genes, and suppress the NF-kappaB activation induced by various carcinogens. We investigated whether guggulsterone could modulate RANKL signaling and osteoclastogenesis induced by RANKL or tumor cells. We found that treatment of monocytes with guggulsterone suppressed RANKL-activated NF-kappaB activation (as indicated by gel-shift assay) and that this suppression correlated with inhibition of IkappaBalpha kinase and phosphorylation and degradation of IkappaBalpha, an inhibitor of NF-kappaB. Guggulsterone also suppressed the differentiation of monocytes to osteoclasts in a dose-dependent and time-dependent manner. Suppression of osteoclastogenesis by the NF-kappaB-specific inhibitory peptide implies a link between NF-kappaB and osteoclastogenesis. Finally, differentiation to osteoclasts induced by coincubating human breast tumor cells (MDA-MB-468) or human multiple myeloma (U266) cells with monocytes was also completely suppressed by guggulsterone. Collectively, our results indicate that guggulsterone suppresses RANKL and tumor cell-induced osteoclastogenesis by suppressing the activation of NF-kappaB.

Curcumin inhibits the proliferation and mineralization of cultured osteoblasts

The effects of curcumin, which is an important constituent of rhizomes of the plant Curcuma longa Linn, on the metabolism of osteoblasts were examined in cultures of rat calvarial osteoblastic cells (ROB cells). The proliferation of cells was markedly inhibited upon exposure of cells to curcumin at 5x10(-6) to 1x10(-5) M. Curcumin at 1x10(-5) M did not induce apoptosis in ROB cells but arrested cells at the G1 phase of the cell cycle. In addition, curcumin stimulated the expression of mRNA for p21(WAF1/CIP1), which inhibits the activity of cyclin-dependent kinases, and inhibited the phosphorylation of histone H1. Furthermore, curcumin reduced the rate of deposition of calcium and the formation of mineralized nodules. Our results indicate that curcumin might inhibit the proliferation and mineralization of osteoblastic cells through the expression of p21(WAF1/CIP1).

From traditional Ayurvedic medicine to modern medicine: identification of therapeutic targets for suppression of inflammation and cancer

Cancer is a hyperproliferative disorder that involves transformation, dysregulation of apoptosis, proliferation, invasion, angiogenesis and metastasis. Extensive research during the last 30 years has revealed much about the biology of cancer. Drugs used to treat most cancers are those that can block cell signalling, including growth factor signalling (e.g., epidermal growth factor); prostaglandin production (e.g., COX-2); inflammation (e.g., inflammatory cytokines: NF-kappaB, TNF, IL-1, IL-6, chemokines); drug resistance gene products (e.g., multi-drug resistance); cell cycle proteins (e.g., cyclin D1 and cyclin E); angiogenesis (e.g., vascular endothelial growth factor); invasion (e.g., matrix metalloproteinases); antiapoptosis (e.g., bcl-2, bcl-X(L), XIAP, survivin, FLIP); and cellular proliferation (e.g., c-myc, AP-1, growth factors). Numerous reports have suggested that Ayurvedic plants and their components mediate their effects by modulating several of these recently identified therapeutic targets. However, Ayurvedic medicine requires rediscovery in light of our current knowledge of allopathic (modern) medicine. The focus of this review is to elucidate the Ayurvedic concept of cancer, including its classification, causes, pathogenesis and prevention; surgical removal of tumours; herbal remedies; dietary modifications; and spiritual treatments.

Hepatocyte growth factor-regulated genes in differentiated RAW 264.7 osteoclast and undifferentiated cells

Hepatocyte Growth Factor (HGF) and its protooncogene receptor c-Met regulate osteoclast function by activating pp60(c-Src) kinase and alpha(v)beta3 integrin. HGF causes transcription yet in osteoclast cells, this gene regulation is currently unknown. To begin characterization of HGF-regulated gene expression in osteoclast cells, we used a well characterized model of osteoclast cells. Using microarray, relative RT-PCR, and Western blot analyses, we have identified and confirmed differentially expressed genes in RAW 264.7 osteoclast cells in response to HGF. HGF regulation of transcription of these genes was concordant with microarray results. We report that HGF downregulates transcription factors, Distal-less 5 (Dlx-5), Distal-less 6 (Dlx-6) and Aristaless 4 (Alx-4), in RAW 264.7 osteoclast cells but has an inverse effect in undifferentiated RAW 264.7 cells.

Resistance to apoptosis of HCW-2 cells can be overcome by curcumin- or vincristine-induced mitotic catastrophe

The term mitotic catastrophe has recently become widely used to describe a form of death affecting many cancer cells, which, because of severe DNA or mitotic spindle damage, are not able to bypass mitosis. We show here that cells of the HL-60-derived HCW-2 line highly resistant to apoptosis, upon treatment with curcumin or vincristine, undergo mitotic catastrophe that is finalized by caspase 3 activation and oligonucleosomal DNA degradation. Curcumin is a natural dye, derived from Curcuma longa that has been shown to induce cell death in many cancer cells. Both treatments decrease cell proliferation and cell survival, arrest cells in G2/M phase of cell cycle and induce morphological changes characterized by cell enlargement and micronucleation. "Catastrophic" cells comprise a separate subpopulation with less than 4C DNA, as evidenced by flow and scanning cytometry. This subpopulation is MPM-2 positive. Thymidine block increased the number of cell arrested in the G2/M phase of cell cycle and curcumin effectiveness as an inducer of mitotic catastrophe. Curcumin, but not vincristine, acts on HCW-2 cells by inhibiting the expression of survivin, a modulator of cell division and apoptosis in cancer. Altogether our results show that apoptosis resistance can be overcome by inducing mitotic catastrophe in HCW-2 cells.

Chemosensitization and radiosensitization of tumors by plant polyphenols

The treatment of cancer with chemotherapeutic agents and radiation has two major problems: time-dependent development of tumor resistance to therapy (chemoresistance and radioresistance) and nonspecific toxicity toward normal cells. Many plant-derived polyphenols have been studied intently for their potential chemopreventive properties and are pharmacologically safe. These compounds include genistein, curcumin, resveratrol, silymarin, caffeic acid phenethyl ester, flavopiridol, emodin, green tea polyphenols, piperine, oleandrin, ursolic acid, and betulinic acid. Recent research has suggested that these plant polyphenols might be used to sensitize tumor cells to chemotherapeutic agents and radiation therapy by inhibiting pathways that lead to treatment resistance. These agents have also been found to be protective from therapy-associated toxicities. How these polyphenols protect normal cells and sensitize tumor cells to treatment is discussed in this review.

The intracellular domain of CD44 promotes the fusion of macrophages

Macrophages seed all tissues in which they have the ability, in specific and rare instances, to fuse with themselves and to differentiate into osteoclasts in bone or into giant cells in chronic inflammatory reactions. Although these cells play a central role in osteoporosis and in foreign body rejection, respectively, the molecular mechanism used by macrophages to fuse remains poorly understood. Macrophages might also fuse with somatic and tumor cells to promote tissue repair and metastasis, respectively. We reported that CD44 expression is highly induced in macrophages at the onset of fusion in which it plays a role. We report now that the intracellular domain of CD44 (CD44ICD) is cleaved in macrophages undergoing fusion and that presenilin inhibitors prevent the release of CD44ICD and fusion. We also show that CD44ICD promotes the fusion of tissue macrophages and bone marrow-derived macrophages. Finally, we report that CD44ICD is localized in the nucleus of macrophages in which it promotes the activation of NF-kappaB. These observations open avenues to study the role of CD44ICD in blood cells and tumors.

Momordin I, an inhibitor of AP-1, suppressed osteoclastogenesis through inhibition of NF-kappaB and AP-1 and also reduced osteoclast activity and survival

Osteoclasts originating from hematopoietic precursor cells differentiate into multinucleated cells through multiple steps. The essential roles of NF-kappaB and AP-1 in osteoclast differentiation have been clearly demonstrated in numerous studies. c-Fos, a component of AP-1 transcription factor, plays a key role in osteoclast differentiation. Recently, we found a strong inhibitor of AP-1 transcriptional activity, named momordin I, based on the structure of oleanolic acid glycosides and originally isolated from Ampelopsis radix. So, we hypothesized that momordin I might be able to regulate osteoclast formation, activity, and survival. Here, we report the ability of momordin I to suppress osteoclastogenesis in a co-cultured system and a RANKL-induced osteoclast precursor system. Momordin I remarkably inhibited the activation of NF-kappaB as well as AP-1 in RANKL-induced RAW264.7 cells, in which momordin I appeared to target IkappaB degradation and c-Fos expression, respectively, but not MAPK signaling pathways. The ability of momordin I to change the ratio of RANKL and OPG in primary osteoblasts was partially responsible for the reduction of osteoclast formation. Furthermore, pit formation on dentin slices was suppressed by momordin I with stimulating actin ring disruption. Our results also showed that momordin I highly shortened osteoclast lifespan and induced osteoclast apoptosis. In conclusion, the present results demonstrate for the first time that momordin I is a potent inhibitor of osteoclast differentiation via the reduction of NF-kappaB and AP-1, and also suppresses osteoclast function and survival.

Suppression of the nuclear factor-kappaB activation pathway by spice-derived phytochemicals: reasoning for seasoning

The activation of nuclear transcription factor kappaB has now been linked with a variety of inflammatory diseases, including cancer, atherosclerosis, myocardial infarction, diabetes, allergy, asthma, arthritis, Crohn's disease, multiple sclerosis, Alzheimer's disease, osteoporosis, psoriasis, septic shock, and AIDS. Extensive research in the last few years has shown that the pathway that activates this transcription factor can be interrupted by phytochemicals derived from spices such as turmeric (curcumin), red pepper (capsaicin), cloves (eugenol), ginger (gingerol), cumin, anise, and fennel (anethol), basil and rosemary (ursolic acid), garlic (diallyl sulfide, S-allylmercaptocysteine, ajoene), and pomegranate (ellagic acid). For the first time, therefore, research provides "reasoning for seasoning."

mu-Calpain regulates receptor activator of NF-kappaB ligand (RANKL)-supported osteoclastogenesis via NF-kappaB activation in RAW 264.7 cells

To clarify the role of calpain in the receptor activator of NF-kappaB ligand (RANKL)-supported osteoclastogenesis, RANKL-induced calpain activation was examined by using murine RAW 264.7 cells and bone marrow-derived monocyte/macrophage progenitors. We found that calpain activity increased in response to RANKL in both cell types based on alpha-spectrinolysis and that mu-calpain, rather than m-calpain, was activated during RANKL-supported osteoclastogenesis in RAW 264.7 cells. Overexpression of mu-calpain clearly augmented RANKL-supported osteoclastogenesis in RAW 264.7 cells, thereby implicating its pivotal role in this process. Cell-permeable calpain inhibitors, including calpastatin and calpeptin, were sufficient to suppress RANKL-supported osteoclastogenesis based on decreased expression of the osteoclastogenic marker, matrix metalloproteinase 9, and the generation of tartrate-resistant acid phosphatase-positive multinucleated cells in both cell types. Calpain inhibitors suppressed NF-kappaB activation via inhibition of the cleavage of inhibitor of NF-kappaB(IkappaBalpha)in RAW 264.7 cells. Taken together, our findings suggest that mu-calpain is essential to the regulation of RANKL-supported osteoclastogenesis via NF-kappaB activation.