The Methuselah Effect: The Pernicious Impact of Unreported Deaths on Old-Age Mortality Estimates.

We examine inferences about old-age mortality that arise when researchers use survey data matched to death records. We show that even small rates of failure to match respondents can lead to substantial bias in the measurement of mortality rates at older ages. This type of measurement error is consequential for three strands in the demographic literature: (1) the deceleration in mortality rates at old ages; (2) the black-white mortality crossover; and (3) the relatively low rate of old-age mortality among Hispanics, often called the "Hispanic paradox." Using the National Longitudinal Survey of Older Men matched to death records in both the U.S. Vital Statistics system and the Social Security Death Index, we demonstrate that even small rates of missing mortality matching plausibly lead to an appearance of mortality deceleration when none exists and can generate a spurious black-white mortality crossover. We confirm these findings using data from the National Health Interview Survey matched to the U.S. Vital Statistics system, a data set known as the "gold standard" (Cowper et al. 2002) for estimating age-specific mortality. Moreover, with these data, we show that the Hispanic paradox is also plausibly explained by a similar undercount.

Antitumor effects of deguelin on H460 human lung cancer cells in vitro and in vivo: Roles of apoptotic cell death and H460 tumor xenografts model.

Deguelin, a naturally occurring rotenoid of the flavonoid family, is known to be an Akt inhibitor, to have chemopreventive activities and anti-tumor effect on several cancers. In this study, investigation to elucidate the effect of deguelin on apoptotic pathways in human lung cancer cells and on the anti-tumor effect in lung cancer xenograft nu/nu mice was performed. In vitro studies, found that deguelin induced cell morphological changes, and decreased the percentage of viability through the induction of apoptosis in H460 lung cancer cells. Deguelin triggered apoptosis in H460 cells was also confirmed by DAPI staining, DNA gel electrophoresis, and Annexin V-FITC staining and these effects are dose-dependent manners. It was also found that deguelin promoted the Ca2+ production and activation of caspase-3 but decreased the level of ΔΨm in H460 cells. Western blots indicated that the protein levels of cytochrome c, AIF, and pro-apoptotic Bax and Bak protein were increased, but the anti-apoptotic Bcl-2 and Bcl-x were decreased that may have led to apoptosis in H460 cells after exposure to deguelin. It was also confirmed by confocal laser microscope examination that deguelin promoted the release of AIF from mitochondria to cytosol. In vivo studies, found that in immunodeficient nu/nu mice bearing H460 tumor xenografts showed that the deguelin significantly suppressed tumor growth. Deguelin might be a potential therapeutic agent for the treatment of lung cancer in the future. This finding might fully support a critical event for deguelin via induction of apoptotic cell death and H460 tumor xenografts model against human lung cancer. © 2015 Wiley Periodicals, Inc. Environ Toxicol 32: 84-98, 2017.

Combining forward and backward mortality estimation.

Demographers often form estimates by combining information from two data sources-a challenging problem when one or both data sources are incomplete. A classic example entails the construction of death probabilities, which requires death counts for the subpopulations under study and corresponding base population estimates. Approaches typically entail 'back projection', as in Wrigley and Schofield's seminal analysis of historical English data, or 'inverse' or 'forward projection' as used by Lee in his important reanalysis of that work, both published in the 1980s. Our paper shows how forward and backward approaches can be optimally combined, using a generalized method of moments (GMM) framework. We apply the method to the estimation of death probabilities for relatively small subpopulations within the United States (men born 1930-39 by state of birth by birth cohort by race), combining data from vital statistics records and census samples.

Role of the mecA gene in oxacillin resistance in a Staphylococcus aureus clinical strain with a pvl-positive ST59 genetic background.

The most prevalent community-associated methicillin-resistant Staphylococcus aureus (C-MRSA) strains in Taiwan, sequence type 59 (ST59) clones, carry staphylococcal cassette chromosome mec (SCCmec) type V and, to a lesser extent, type IV. These strains show wide variation in sensitivity to oxacillin, but the reasons for this variation are unknown. Here we compared the sequences of the mecA genes from clinical strains of different SCCmec types and found that they contain different mecA promoter mutations. Analysis of mecA promoter activity by reporter gene fusions showed that single base substitutions in the promoter have a strong influence on mecA transcription. The different mecA variants, including promoter sequences, were expressed in the methicillin-sensitive Staphylococcus aureus (MSSA) strain C195 (ST59 background). PBP 2a production among the parental strains and strains with promoter mutant mecA genes showed a close correlation with mecA transcription levels. Furthermore, the quantity of PBP 2a also closely correlated with the level of oxacillin resistance in the C195 background. Our data suggest that mecA promoter mutations play an important role in determining the level of oxacillin resistance. The mecA promoter mutation G-25A (25 bases upstream of the mecA translation start site) was found to be associated with a high oxacillin MIC (256 µg/ml), G-7T conferred a moderate oxacillin MIC (32 to 64 µg/ml), strains with C-33T showed a low oxacillin MIC (4 to 8 µg/ml), and A-38G reversed the effect of the C-33T mutation, restoring the oxacillin resistance level in the A-38G C-33T double mutant. These observations may explain why C-MRSA strains in Taiwan carrying SCCmec type IV or V have such enormous variations in oxacillin MICs.

Solution-Processed Flexible Temperature Sensor Array for Highly Resolved Spatial Temperature and Tactile Mapping Using ESN-Based Data Interpolation.

High-performance flexible temperature sensors are crucial in various technological applications, such as monitoring environmental conditions and human healthcare. The ideal characteristics of these sensors for stable temperature monitoring include scalability, mechanical flexibility, and high sensitivity. Moreover, simplicity and low power consumption will be essential for temperature sensor arrays in future integrated systems. This study introduces a solution-based approach for creating a V2O5 nanowire network temperature sensor on a flexible film. Through optimization of the fabrication conditions, the sensor exhibits remarkable performance, sustaining long-term stability (>110 h) with minimal hysteresis and excellent sensitivity (∼-1.5%/°C). In addition, this study employs machine learning techniques for data interpolation among sensors, thereby enhancing the spatial resolution of temperature measurements and adding tactile mapping without increasing the sensor count. Introducing this methodology results in an improved understanding of temperature variations, advancing the capabilities of flexible-sensor arrays for various applications.

Efficacy of Lactococcus lactis subsp. lactis LY-66 and Lactobacillus plantarum PL-02 in Enhancing Explosive Strength and Endurance: A Randomized, Double-Blinded Clinical Trial.

Probiotics are posited to enhance exercise performance by influencing muscle protein synthesis, augmenting glycogen storage, and reducing inflammation. This double-blind study randomized 88 participants to receive a six-week intervention with either a placebo, Lactococcus lactis subsp. lactis LY-66, Lactobacillus plantarum PL-02, or a combination of both strains, combined with a structured exercise training program. We assessed changes in maximal oxygen consumption (VO2max), exercise performance, and gut microbiota composition before and after the intervention. Further analyses were conducted to evaluate the impact of probiotics on exercise-induced muscle damage (EIMD), muscle integrity, and inflammatory markers in the blood, 24 and 48 h post-intervention. The results demonstrated that all probiotic groups exhibited significant enhancements in exercise performance and attenuation of muscle strength decline post-exercise exhaustion (p < 0.05). Notably, PL-02 intake significantly increased muscle mass, whereas LY-66 and the combination therapy significantly reduced body fat percentage (p < 0.05). Analysis of intestinal microbiota revealed an increase in beneficial bacteria, especially a significant rise in Akkermansia muciniphila following supplementation with PL-02 and LY-66 (p < 0.05). Overall, the combination of exercise training and supplementation with PL-02, LY-66, and their combination improved muscle strength, explosiveness, and endurance performance, and had beneficial effects on body composition and gastrointestinal health, as evidenced by data obtained from non-athlete participants.

Probiotic Lactobacillus fermentum TSF331, Lactobacillus reuteri TSR332, and Lactobacillus plantarum TSP05 improved liver function and uric acid management-A pilot study.

Metabolic-associated fatty liver disease (MAFLD) is predominantly associated with metabolic disturbances representing aberrant liver function and increased uric acid (UA) levels. Growing evidences have suggested a close relationship between metabolic disturbances and the gut microbiota. A placebo-controlled, double-blinded, randomized clinical trial was therefore conducted to explore the impacts of daily supplements with various combinations of the probiotics, Lactobacillus fermentum TSF331, Lactobacillus reuteri TSR332, and Lactobacillus plantarum TSP05 with a focus on liver function and serum UA levels. Test subjects with abnormal levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and UA were recruited and randomly allocated into six groups. Eighty-two participants successfully completed the 60-day intervention without any dropouts or occurrence of adverse events. The serum AST, ALT, and UA levels were significantly reduced in all treatment groups (P < 0.05). The fecal microbiota analysis revealed the intervention led to an increase in the population of commensal bacteria and a decrease in pathobiont bacteria, especially Bilophila wadsworthia. The in vitro study indicated the probiotic treatments reduced lipid accumulation and inflammatory factor expressions in HepG2 cells, and also promoted UA excretion in Caco-2 cells. The supplementation of multi-strain probiotics (TSF331, TSR332, and TSP05) together can improve liver function and UA management and may have good potential in treating asymptomatic MAFLD. Trial registration. The trial was registered in the US Library of Medicine (clinicaltrials.gov) with the number NCT06183801 on December 28, 2023.

Aptamer-Engineered Cu2O Nanocubes as a Surface-Modulated Catalytic Optical Sensor for Lung Cancer Cell Detection.

Herein, fine and homogeneous Cu2O nanocubes are synthesized and sensitized with a hairpin-structured AS1411 aptamer for the establishment of a biosensor for lung cancer cell detection. The Apt-Cu2O nanocubes feature a recognition function in identifying a cancer-associated surface nucleolin protein. The intrinsic reduction catalytic ability is also confirmed by the use of two benchmark substrates, methylene blue (MB) and 4-nitrophenol (4-NP). The aptamer grafting on Apt-Cu2O nanocubes is able to greatly prevent nonspecific-protein binding and to show specificity toward the nucleolin protein. The specific binding resulting from nucleolin protein leads to less exposure of the active area of the Apt-Cu2O nanocubes, so the catalytic ability of Apt-Cu2O nanocubes is thus diminished. The modulated catalytic ability led to less generation of the reduced 4-AP product, and the change in absorption of 4-AP allows the quantification of the nucleolin protein with a detection limit of 0.47 nM. The as-developed biosensor is applied to the detection of nucleolin-overexpressed A549 lung cancer cells, presenting a sensitive detection limit down to 20 cells. This may be ascribed to the clustering of surface nucleolin protein in a lipid raft membrane of cancer cells, as evidenced by a notable binding of Apt-Cu2O nanocubes on the cancer cell surface. Real human serum samples spiked with cancer cells were also investigated, and a recovery rate of 87 ± 2.4% for 20 extracted cells validates the surface-modulated Apt-Cu2O nanocubes-based catalytic optical biosensor as a promising tool for the detection of circulating tumor cells. The establishment of the Apt-Cu2O nanocubes may allow for further studies on their use as a potential theranostics tool for cancer therapy.

Rational Design on Polymorphous Phase Switching in Molybdenum Diselenide-Based Memristor Assisted by All-Solid-State Reversible Intercalation toward Neuromorphic Application.

In this work, a low-power memristor based on vertically stacked two-dimensional (2D) layered materials, achieved by plasma-assisted vapor reaction, as the switching material, with which the copper and gold metals as electrodes featured by reversible polymorphous phase changes from a conducting 1T-phase to a semiconducting 2H-one once copper cations interacted between vertical lamellar layers and vice versa, was demonstrated. Here, molybdenum diselenide was chosen as the switching material, and the reversible polymorphous phase changes activated by the intercalation of Cu cations were confirmed by pseudo-operando Raman scattering, transmission electron microscopy, and scanning photoelectron microscopy under high and low resistance states, respectively. The switching can be activated at about ±1 V with critical currents less than 10 µA with an on/off ratio approaching 100 after 100 cycles and low power consumption of ∼0.1 microwatt as well as linear weight updates controlled by the amount of intercalation. The work provides alternative feasibility of reversible and all-solid-state metal interactions, which benefits monolithic integrations of 2D materials into operative electronic circuits.

Probiotic Formula Ameliorates Renal Dysfunction Indicators, Glycemic Levels, and Blood Pressure in a Diabetic Nephropathy Mouse Model.

One-third of patients with end-stage chronic kidney disease (CKD) experience diabetic nephropathy (DN), which worsens the progression of renal dysfunction. However, preventive measures for DN are lacking. Lactobacillus acidophilus TYCA06, Bifidobacterium longum subsp. infantis BLI-02, and Bifidobacterium bifidum VDD088 probiotic strains have been demonstrated to delay CKD progression. This study evaluated their biological functions to stabilize blood-glucose fluctuations and delay the deterioration of renal function. The db/db mice were used to establish a DN animal model. This was supplemented with 5.125 × 109 CFU/kg/day (high dose) or 1.025 × 109 CFU/kg/day (low dose) mixed with probiotics containing TYCA06, BLI-02, and VDD088 for 8 weeks. Blood urea nitrogen (BUN), serum creatinine, blood glucose, and urine protein were analyzed. Possible mechanisms underlying the alleviation of DN symptoms by probiotic strains were evaluated through in vitro tests. Animal experiments revealed that BUN, serum creatinine, and blood glucose upon probiotic administration were significantly lower than in the control group. The rate of change of urine protein decreased significantly, and blood pressure, glucose tolerance, and renal fibrosis were improved. In vitro testing indicated that TYCA06 and BLI-02 significantly increased acetic acid concentration. TYCA06, BLI-02, and VDD088 were associated with better antioxidation, anti-inflammation, and glucose consumption activities relative to the control. A combination of the probiotics TYCA06, BLI-02, and VDD088 attenuated renal function deterioration and improved blood-glucose fluctuation in a diabetes-induced CKD mouse model.

Efficacy of Probiotic Supplements on Brain-Derived Neurotrophic Factor, Inflammatory Biomarkers, Oxidative Stress and Cognitive Function in Patients with Alzheimer's Dementia: A 12-Week Randomized, Double-Blind Active-Controlled Study.

The role of neurotrophic factors, oxidative stress, and inflammation in the pathogenesis of Alzheimer's disease (AD) has been explored. Animal studies have reported the positive effects of probiotics on these factors. Some clinical studies also support the potential role of probiotics in improving cognitive function via the gut-brain axis in older adults. However, clinical experimental studies evaluating the efficacy of probiotics targeting the neurotrophic factors and inflammatory biomarkers, particularly among AD patients, remain very limited. In this randomized, double-blinded, active-controlled trial, we used multi-strain probiotic supplements, including Bifidobacterium longum subsp. infantis BLI-02, B. breve Bv-889, B. animalis subsp. lactis CP-9, B. bifidum VDD088, and Lactobacillus plantarum PL-02 as the intervention. Participants were divided into an active control group (received probiotic supplements containing 5 × 107 colony-forming units per day, CFU/day) and a treatment group (1 × 1010 CFU/day). Student's t test was applied as the main method of statistical analysis. After 12 weeks of intervention, the treatment group demonstrated a 36% increase in serum brain-derived neurotrophic factor (BDNF) (* p = 0.005), a reduction in IL-1ß (* p = 0.041), and an increase in antioxidant superoxide dismutase (SOD) (* p = 0.012). No significant change was found in the active control group. A trend toward less cognitive deterioration was observed, but not statistically significant. In conclusion, this study presents evidence supporting the benefits of multi-strain probiotics in enhancing BDNF, ameliorating inflammation and oxidative stress in AD patients.

Safety Assessment and Probiotic Potential Comparison of Bifidobacterium longum subsp. infantis BLI-02, Lactobacillus plantarum LPL28, Lactobacillus acidophilus TYCA06, and Lactobacillus paracasei ET-66.

Bifidobacterium longum subsp. infantis BLI-02, Lactobacillus paracasei ET-66, Lactobacillus plantarum LPL28, and Lactobacillus acidophilus TYCA06, isolated from healthy breast milk, miso, and the healthy human gut, were assessed for safety in this study. BLI-02, LPL28, TYCA06, and ET-66 exhibited no antibiotic resistance and mutagenic activity in the Ames test at the highest dosage (5000 µg/plate). No genotoxicity was observed in micronucleus and chromosomal aberration assays in rodent spermatogonia at the maximum dosage of 10 g/kg body weight (BW). No acute and sub-chronic toxicity occurred in mice and rats at the maximum tested dosage of 10 g/kg BW and 1.5 g/kg BW, respectively. The lyophilized powder of these strains survived a low pH and high bile salt environment, adhering strongly to Caco-2 cells. Unique antimicrobial activities were noted in these strains, with BLI-02 demonstrating the best growth inhibition against Vibrio parahaemolyticus, LPL28 exhibiting the best growth inhibition against Helicobacter pylori, and ET-66 showing the best growth inhibition against Aggregatibacter actinomycetemcomitans. Based on the present study, the lyophilized powder of these four strains appears to be a safe probiotic supplement at tested dosages. It should be applicable for clinical or healthcare applications.

A benzamide-linked small molecule NDMC101 inhibits NFATc1 and NF-κB activity: a potential osteoclastogenesis inhibitor for experimental arthritis.

PURPOSE: Using receptor activator of NF-κB ligand (RANKL) induced osteoclast differentiation on RAW264.7 as a screening tool; we synthesize and identify small-molecule inhibitors preserving immunomodulatory effects as therapeutics for rheumatoid arthritis. METHODS: Differentiation into osteoclast-like cells was examined by tartrate-resistant acid phosphatase (TRAP) staining and expression of osteoclast differentiation markers. Collagen-induced arthritis (CIA) mice were administered test articles by gavages to assess its efficacy. Then clinical, histological, and biochemical parameters were assessed to determine the effects of N-(4-chloro-2-fluorophenyl)-2-hydroxybenzamide (NDMC101) on synovial inflammation and bone erosion by hematoxlin and eosin staining and Enzyme-linked immunosorbent assay (ELISA). RESULTS: NDMC101 markedly inhibited RANKL-induced formation of TRAP+ multinucleated cells in RAW264.7 and bone marrow macrophage cells (BMMs). Moreover, pit formation assay showed that NDMC101 significantly reduced the bone-resorbing activity of mature osteoclasts. In CIA mice, oral administration of NDMC101 reduced arthritic index and mitigated bone erosion. Serum TNF-α and IL-1ß concentrations in these mice were decreased significantly at the higher dose of 62.5 mg/kg. CONCLUSIONS: Screening of our chemical library, our findings suggest that NDMC101 inhibits osteoclastogenesis which also ameliorates paw swelling and inflammatory bone destruction. Its efficacy is associated with the inhibition of such transcription factors as NF-κB and NFATc1 as well as multiple protein kinases, including p38, ERK, and JNK. There results guarantee further clinical tests of NDMC101 for its therapeutic potential in the treatment of inflammation-induced bone diseases.

In Situ Current-Accelerated Phase Cycling with Metallic and Semiconducting Switching in Copper Nanobelts at Room Temperature.

Here, a current-accelerated phase cycling by an in situ current-induced oxidation process was demonstrated to reversibly switch the local metallic Cu and semiconducting Cu2O phases of patterned polycrystalline copper nanobelts. Once the Cu nanobelts were applied by a direct-current bias of ∼0.5 to 1 V in air with opposite polarities, the resistance between several hundred ohms and more than MΩ can be manipulated. In practice, the thickness of 60 nm with a moderate grain size inhibiting both electromigration and permanent oxidation is the optimized condition for reversible switching when the oxygen supply is sufficient. More than 40% of the copper localized beneath the positively biased electrode was oxidized assisted by the Joule heating, blocking the current flow. On the contrary, the reduction reaction of Cu2O was activated by the thermally assisted electromigration of Cu atoms penetrating the interlayer at the reverse bias. Finally, based on a high on/off ratio, the fast switching and the scalable production, reusable feasibility based on copper nanobelts such as the memristor array was demonstrated.

Design of Core-Shell Quantum Dots-3D WS2 Nanowall Hybrid Nanostructures with High-Performance Bifunctional Sensing Applications.

Transition metal dichalcogenides (TMDCs) have recently attracted a tremendous amount of attention owing to their superior optical and electrical properties as well as the interesting and various nanostructures that are created by different synthesis processes. However, the atomic thickness of TMDCs limits the light absorption and results in the weak performance of optoelectronic devices, such as photodetectors. Here, we demonstrate the approach to increase the surface area of TMDCs by a one-step synthesis process of TMDC nanowalls from WOx into three-dimensional (3D) WS2 nanowalls. By utilizing a rapid heating and rapid cooling process, the formation of 3D nanowalls with a height of approximately 150 nm standing perpendicularly on top of the substrate can be achieved. The combination of core-shell colloidal quantum dots (QDs) with three different emission wavelengths and 3D WS2 nanowalls further improves the performance of WS2-based photodetector devices, including a photocurrent enhancement of 320-470% and shorter response time. The significant results of the core-shell QD-WS2 hybrid devices can be contributed by the high nonradiative energy transfer efficiency between core-shell QDs and the nanostructured material, which is caused by the spectral overlap between the emission of core-shell QDs and the absorption of WS2. Besides, outstanding NO2 gas-sensing performance of core-shell QDs/WS2 devices can be achieved with an extremely low detection limit of 50 ppb and a fast response time of 26.8 s because of local p-n junctions generated by p-type 3D WS2 nanowalls and n-type core-shell CdSe-ZnS QDs. Our work successfully reveals the energy transfer phenomenon in core-shell QD-WS2 hybrid devices and shows great potential in commercial multifunctional sensing applications.

Effect of a Point Mutation in mprF on Susceptibility to Daptomycin, Vancomycin, and Oxacillin in an MRSA Clinical Strain.

We previously reported the sequential recovery of daptomycin-nonsusceptible MRSA clinical isolates with an L431F substitution in the MprF protein. The aim of the present study is to determine the effect of this mutation by replacing the mprF gene on the chromosome of a daptomycin-susceptible progenitor strain, CGK5, to obtain CGK5mut having the L431F MprF mutation. Compared to CGK5, the daptomycin and vancomycin MICs of CGK5mut increased from 0.5 to 3 µg/ml and from 1.5 to 3 µg/ml, respectively; however, its oxacillin MIC decreased from 128 to 1 µg/ml in medium without added 2% NaCl. The expression levels of vraSR and several other cell-wall synthesis-related genes were significantly increased in CGK5mut, and the mutant also had significantly reduced negative cell membrane charge, thicker cell wall, and longer doubling time. These features were abolished in the reverse mutant carrying F431L MprF, confirming the pleiotropic effects of the L431F MprF mutation. We believe that this is the first work that shows a single MprF missense mutation can lead to not only changes in the cell membrane but also increased expression of vraSR and subsequently increased resistance to daptomycin and vancomycin while simultaneously conferring increased susceptibility to oxacillin in an isogenic MRSA strain.

Effects of solvent immiscibility on the phase behavior and microstructural length scales of a diblock copolymer in the presence of two solvents.

We employ self-consistent mean-field theory to study the phase behavior and the microstructural sizes of AB diblock copolymers in the presence of a neutral solvent S1 and a slightly B-selective solvent S2. In particular, the effects of copolymer volume fraction phiC, the solvent ratio, and the immiscibility parameter between two solvents chiS1S2, are examined. We find that increasing chiS1S2 not only enlarges the ordered microphase region in the concentrated solutions, but also induces a less concentrated homogeneous solution to form an ordered structure and even undergo a macrophase separation. This is due to the fact that increasing chiS1S2 enhances the preferentially of S1 for A and S2 for B and, thereafter, the effective segregation between A and B. Hence, we observe that the structural length results obtained by varying chiS1S2 resemble a consequence of varying the solvent selectivity in the diblock copolymer solutions when only one solvent is added. For example, when chiS1S2 is small, the domain spacing decreases with decreasing phiC while at larger values of chiS1S2, it first shows a decreasing trend and then an increasing behavior with decreasing phiC.

The effect of early-life education on later-life mortality.

Many studies link cross-state variation in compulsory schooling laws to early-life educational attainment, thereby providing a plausible way to investigate the causal impact of education on various lifetime outcomes. We use this strategy to estimate the effect of education on older-age mortality of individuals born in the early twentieth century U.S. Our key innovation is to combine U.S. Census data and the complete Vital Statistics records to form precise mortality estimates by sex, birth cohort, and birth state. In turn we find that virtually all of the variation in these mortality rates is captured by cohort effects and state effects alone, making it impossible to reliably tease out any additional impact due to changing educational attainment induced by state-level changes in compulsory schooling.

Plectranthus amboinicus attenuates inflammatory bone erosion in mice with collagen-induced arthritis by downregulation of RANKL-induced NFATc1 expression.

OBJECTIVE: Plectranthus amboinicus has been known to treat inflammatory diseases or swelling symptoms. We investigated whether P. amboinicus exhibited an inhibitory effect on osteoclastogenesis in vitro and inflammatory bone erosion in collagen-induced arthritis (CIA) mice, an animal model of rheumatoid arthritis. We attempted to identify the active component of P. amboinicus involved in regulation of osteoclastogenesis. METHODS: We treated M-CSF- and RANKL-stimulated murine bone marrow-derived macrophages (BMM) and RANKL-induced RAW264.7 cells with different concentrations of P. amboinicus or rosmarinic acid, a phytopolyphenol purified from P. amboinicus, to monitor osteoclast formation by TRAP staining. The mechanism of the inhibition was studied by biochemical analysis such as RT-PCR and immunoblotting. CIA mice were administered gavages of P. amboinicus (375 mg/kg) or placebo. Then clinical, histological, and biochemical measures were assessed to determine the effects of P. amboinicus on synovial inflammation and bone erosion by H&E staining of the inflamed joints and ELISA. RESULTS: Rosmarinic acid strongly inhibited RANKL-induced NF-κB activation and nuclear factor of activated T cells c1 (NFATc1) nuclear translocation in BMM, and also inhibited RANKL-induced formation of TRAP-positive multinucleated cells. A pit formation assay and the CIA animal model showed that P. amboinicus significantly inhibited the bone-resorbing activity of mature osteoclasts. CONCLUSION: We postulated that rosmarinic acid conferred the inhibitory activity on P. amboinicus for inhibition of osteoclastogenesis via downregulation of RANKL-induced NFATc1 expression. Our results indicated the possibility of P. amboinicus as a new remedy against inflammatory bone destruction.