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1.
J Ethnopharmacol ; 330: 118229, 2024 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-38670403

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Thymus quinquecostatus Celak., a member of thymus genus in Lamiaceae family, has been used as a folk medicine for relieving exterior syndrome and alleviating pain in China. The polyphenol-rich fraction (PRF) derived from Thymus quinquecostatus Celak. had been validated that it can protect cerebral ischemia-reperfusion injury (CIRI) by activating Keap1/Nrf2/HO-1 signaling pathway. AIM OF THIS STUDY: To explore effective components and their pharmacokinetic and pharmacodynamic characteristics as well as possible mechanisms of PRF in treating CIRI. MATERIALS AND METHODS: Normal treated group (NTG) and tMCAO model treated group (MTG) rats were administrated PRF intragastrically. The prototype components and metabolites of PRF in plasma and brain were analyzed by the UPLC-Q-Exactive Orbitrap MSn method. Subsequently, the pharmacokinetics properties of indicative components were performed based on HPLC-QQQ-MS/MS. SOD and LDH activities were determined to study the pharmacodynamic (PD) properties of PRF. The PK-PD relationship of PRF was constructed. In addition, the effect of PRF on endogenous metabolites in plasma and brain was investigated using metabolomic method. RESULTS: Salvianic acid A, caffeic acid, rosmarinic acid, scutellarin, and apigenin-7-O-glucuronide were selected as indicative components based on metabolic analysis. The non-compartmental parameters were calculated for indicative components in plasma and brain of NTG and MTG rats. Furthermore, single-component and multi-component PK-PD modeling involved Emax, Imax PD models for effect indexes were fitted as well as ANN models were established, which indicated that these components can work together to regulate SOD and LDH activities in plasma and SOD activity in brain tissue to improve CIRI. Additionally, PRF may ameliorate CIRI by regulating the disorder of endogenous metabolites in lipid metabolism, amino acid metabolism, and purine metabolism pathways in vivo, among which lipid metabolism and purine metabolism are closely related to oxidative stress. CONCLUSION: The PK-PD properties of effect substances and mechanisms of PRF anti-CIRI were further elaborated. The findings provide a convincing foundation for the application of T. quinquecostatus Celak. in the maintenance of human health disorders.


Asunto(s)
Metabolómica , Polifenoles , Ratas Sprague-Dawley , Daño por Reperfusión , Thymus (Planta) , Animales , Masculino , Daño por Reperfusión/tratamiento farmacológico , Daño por Reperfusión/metabolismo , Thymus (Planta)/química , Polifenoles/farmacología , Polifenoles/farmacocinética , Ratas , Infarto de la Arteria Cerebral Media/tratamiento farmacológico , Extractos Vegetales/farmacología , Extractos Vegetales/farmacocinética , Encéfalo/metabolismo , Encéfalo/efectos de los fármacos , Modelos Animales de Enfermedad , Isquemia Encefálica/tratamiento farmacológico , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/farmacocinética , Medicamentos Herbarios Chinos/farmacología , Medicamentos Herbarios Chinos/farmacocinética
2.
Curr Med Chem ; 30(9): 1060-1085, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-35927899

RESUMEN

BACKGROUND: 2,5-Diketopiperazines (DKPs), also called cyclic dipeptides, are the simplest peptide derivatives in nature that are formed by the condensation of two amino acids. They are an important category of bioactive substances with various structures. OBJECTIVE: This review focuses on the natural sources, synthetic processes, biological properties and MS fragmentation regularity of simple DKPs, in order to provide a reference for exploring future scientific and therapeutic potentials of these compounds. METHODS: Pertinent information was collected and organized from several electronic scientific databases (e.g., Web of Science, China Knowledge Resource Integrated, ScienceDirect, PubMed, Wanfang Data and Google Scholar), PhD and MS dissertations. There are 107 articles published from the early 20th century to 2021 that were reviewed in this work. RESULTS: DKPs have been obtained from a broad range of natural resources, including fungi, bacteria, plants, and animals, and have been synthesized by chemical and biological methods. DKPs have various pharmacological activities, including anticancer, antibacterial, antithrombotic, neuron protective, analgesic, and other activities. Mass spectrometry is the most common method for the structural analysis of DKPs. DKPs can be quickly screened and identified by MS according to the mass spectrum fragmentation pattern. CONCLUSION: As a category of relatively unexplored compounds, DKPs have been demonstrated to have various bioactivities, especially with antitumor and antibacterial activities. However, the existing research on DKPs is still in the early stage, and their application in drug development needs to be further studied.


Asunto(s)
Antibacterianos , Dicetopiperazinas , Animales , Dicetopiperazinas/química , Dicetopiperazinas/metabolismo , Dicetopiperazinas/farmacología , Antibacterianos/farmacología , Hongos/metabolismo , Bacterias/metabolismo
3.
Front Pharmacol ; 13: 1027687, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36561345

RESUMEN

Objective: Curcumae Rhizoma-Sparganii Rhizoma (CR-SR) is a traditional botanical drug pair that can promote blood circulation, remove blood stasis, and treat tumors in clinics. The aim of the present study was to investigate the therapeutic material basis and potential mechanisms of CR-SR, CR, and SR for the treatment of liver cancer. Method: The chemical profile analyses of CR-SR, CR, and SR were performed by molecular networking and UPLC-LTQ-Orbitrap MSn. The anti-liver cancer activities of CR-SR, CR, and SR were assessed by using a zebrafish xenograft model in vivo for the first time and detected by the HepG2 cell model in vitro. Combining the network analysis and molecular docking, real-time quantitative polymerase chain reaction (RT-qPCR) experiments were undertaken to further explore the mechanisms of CR-SR, CR, and SR for the treatment of liver cancer. Results: In total, 65 components were identified in CR-SR, CR, and SR. Based on the clusters of molecular networking, a total of 12 novel diarylheptanoids were identified from CR-SR and CR. By combining our results with information from the literature, 32 sesquiterpenoids and 21 cyclic dipeptides were identified from CR-SR, CR, and SR. The anti-liver cancer activities were observed in both the drug pair and the single botanical drugs in vitro and in vivo, and the order of activity was CR-SR > CR > SR. They could downregulate the expression of proto-oncogene tyrosine-protein kinase Src (SRC), epidermal growth factor receptor (EGFR), estrogen receptor-α (ESR1), prostaglandin endoperoxide synthase 2 (PTGS2), and amyloid precursor protein (APP). Conclusion: Taken together, the present study provided an experimental basis for the therapeutic material basis and potential molecular mechanisms of CR-SR, CR, and SR. This study provided a novel insight for objective clinical treatment of liver cancer.

4.
Am J Chin Med ; 50(2): 471-509, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35168475

RESUMEN

Dendrobium polysaccharides (DPSs) have aroused people's increasing attention in recent years as a result of their outstanding edible and medicinal values and non-toxic property. This review systematically summarized recent progress in the different preparation techniques, structural characteristics, modification, various pharmacological activities and molecular mechanisms, structure-activity relationships, and current industrial applications in the medicinal, food, and cosmetics fields of DPSs. Additionally, some recommendations for future investigations were provided. A variety of methods were applied for the extraction and purification of DPSs. They possessed primary structures (e.g., glucomannan, rhamnogalacturonan I type pectin, heteroxylan, and galactoglucan) and conformational structures (e.g., random coil, rod, globular, and a slight triple-helical). And different molecular weights, monosaccharide compositions, linkage types, and modifications could largely affect DPSs' bioactivities (e.g., immunomodulatory, anti-diabetic, hepatoprotective, gastrointestinal protective, antitumor, anti-inflammatory, and anti-oxidant activities). It was worth mentioning that DPSs were significant pharmaceutical remedies and therapeutic supplements especially due to their strong immunity enhancement abilities. We hope that this review will lay a solid foundation for further development and applications of Dendrobium polysaccharides.


Asunto(s)
Dendrobium , Antiinflamatorios , Antioxidantes/farmacología , Dendrobium/química , Humanos , Polisacáridos
5.
Neurochem Res ; 47(4): 1037-1048, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35037165

RESUMEN

Curcumin is a natural polyphenolic compound with neuroprotective and antioxidant properties. Acrylamide (ACR) is a by-product of food processing that produces neurotoxicity in humans and animals. The pancreatic endoplasmic reticulum kinase (PERK)-eukaryotic initiation factor-2α (eIF2α) signaling is involved in the occurrence of neurotoxicities. This study is aimed to investigate the protective effect of curcumin on ACR-induced cytotoxicity and explore the role of PERK-eIF2α signaling in this process. ACR exposure at 2.5 mM for 24 h caused oxidative stress as revealed by the distinct increase in cellular reactive oxygen species (ROS) and malondialdehyde (MDA) level, and a significant decrease in glutathione (GSH) content. ACR induced phosphorylated tau aggregation, phosphorylated cAMP response elements binding protein (CREB) reduction, and Bax/Bcl-2 ratio up-regulation in SH-SY5Y cells. ACR also activated the PERK-eIF2α signaling in SH-SY5Y cells and triggered the activation of glycogen synthase kinase-3ß (GSK-3ß), up-regulated activating transcription factor 4 (ATF4) and C/EBP homologous protein (CHOP). Curcumin pretreatment significantly attenuated ACR-induced neuronal toxicity as revealed by the ameliorated cell viability, mitigated intracellular ROS and MDA level, and elevated GSH content. Moreover, curcumin pretreatment inhibited PERK-dependent eIF2α phosphorylation, further suppressed GSK-3ß and ATF4 function, and abolished abnormal tau phosphorylation, P-CREB reduction, and CHOP-induced apoptosis in SH-SY5Y cells. These results provided empirical evidence between curcumin and PERK-eIF2α signaling in ACR-induced neurotoxicity.


Asunto(s)
Curcumina , Factor 2 Eucariótico de Iniciación , Neuroblastoma , eIF-2 Quinasa , Acrilamida/toxicidad , Animales , Apoptosis , Línea Celular Tumoral , Curcumina/farmacología , Factor 2 Eucariótico de Iniciación/metabolismo , Glucógeno Sintasa Quinasa 3 beta , Humanos , Estrés Oxidativo , eIF-2 Quinasa/metabolismo
6.
J Ethnopharmacol ; 280: 114439, 2021 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-34293455

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Curcumae Rhizoma-Sparganii Rhizoma (CR-SR), an ancient and classical herbal couple, has been extensively used for tumor treatment in clinic of traditional Chinese medicines (TCMs). AIM OF THE STUDY: The study aimed to uncover the anti-tumor active materials of CR-SR water decoction (CR:SR = 1:1) via an integrated approach of spectrum-effect relationship, molecular docking, and ADME evaluation. MATERIALS AND METHODS: The anti-tumor activities toward A549, HepG2, Hela, BGC-823, and MCF-7 cells of the different polar elution fractions (DPEFs) of CR, SR, and CR-SR were determined by Cell Counting Kit-8 (CCK-8) assay. Likewise, the DPEFs' combinations of CR and SR were also tested. The chemical fingerprints of these fractions were profiled by HPLC. Meanwhile, HPLC-ESI-Q-TOF-MS/MS was applied for the identification of chemical components. The main effect-related compounds were screened out by spectrum-effect relationship and molecular docking method. The oral bioavailability and druggability of these active components were subsequently evaluated. Finally, five monomeric compounds were validated experimentally using HepG2 cells. RESULTS: The 80% ethanol elution fraction of CR, SR, and CR-SR showed strong anti-tumor effects toward five cells. Also, the combinations with the 80% ethanol elution fraction of CR and SR showed stronger tumor inhibition effects among the DPEFs' combinations of CR and SR. By spectrum-effect relationship, HPLC-MS, and molecular docking analysis, 24 main effect-related compounds seemed to have potential anti-tumor effects. ADME evaluation showed rutin performed low oral bioavailability and druggability. Therefore, we suppose that 23 compounds (including 4 unknown compounds) are the primary anti-tumor active components of CR-SR water decoction. Among them, zederone, curcumol, chlorogenic acid, calycosin, and curcumenol were validated successfully with good tumor inhibition effects. CONCLUSIONS: In summary, this study demonstrated that the multi-components of CR-SR contribute to its anti-tumor effects. It established a rapid and useful strategy to explore the active material basis of traditional Chinese herbal couples with a multi-technology integrated approach in practice, including chromatography, mass spectrometry, machine algorithm models, online databases, and in vitro cell experiments.


Asunto(s)
Antineoplásicos/farmacología , Curcuma/química , Medicamentos Herbarios Chinos/farmacocinética , Medicamentos Herbarios Chinos/uso terapéutico , Raíces de Plantas/química , Typhaceae/química , Antineoplásicos/química , Línea Celular Tumoral , Humanos , Simulación del Acoplamiento Molecular , Fitoterapia , Reproducibilidad de los Resultados
7.
Placenta ; 103: 16-23, 2021 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-33068962

RESUMEN

OBJECTIVE: To analyze the effects of the Human Chorionic Gonadotropin beta (ß-hCG) and the VEGF-MEK/ERK signaling pathway on villi angiogenesis in early missed abortion. METHODS: A total of 12 cases of women with missed abortion and 12 cases of women who had induced abortion voluntarily without any disease were included in the present study. The age, pregnancy time and gestation period in the control group corresponded to the missed abortion group. Wes Simple Western system and qRT-PCR were used to detect the expression of VEGF-MEK/ERK signaling pathway related proteins and genes in villous. Radioimmunoassay and Enzyme-linked immunosorbent assay were used to detect ß-hCG and VEGF levels in serum. The microvascular density (MVD) in villous tissue was analyzed by immunohistochemical staining. RESULTS: The levels of ß-hCG and VEGF in serum, the expression of VEGF-MEK/ERK signaling pathway and MVD in villous tissue of the missed abortion group were lower than those of the control group. In addition, compared with the control group, the layers of trophoblasts of the villous tissue in the missed abortion group became thinner significantly, the number of cells reduced, the cell structures were disorganized, and parts of the trophoblast cells were absent. Correlational analysis showed that the protein expression of ERK1/2 was positively correlated with MVD in missed abortion group. CONCLUSIONS: Our results reveal that decreased production of ß-hCG in early pregnant women could down-regulate the expression of VEGF-MEK/ERK signal pathway, then reduce angiogenesis and eventually leading to the abnormal angiogenesis of villous, which may be an important mechanism of missed abortion.


Asunto(s)
Aborto Retenido/genética , Gonadotropina Coriónica Humana de Subunidad beta/fisiología , Vellosidades Coriónicas/irrigación sanguínea , Sistema de Señalización de MAP Quinasas/fisiología , Factor A de Crecimiento Endotelial Vascular/fisiología , Aborto Inducido/efectos adversos , Aborto Retenido/metabolismo , Aborto Espontáneo/genética , Aborto Espontáneo/metabolismo , Aborto Espontáneo/patología , Adulto , Estudios de Casos y Controles , Vellosidades Coriónicas/metabolismo , Vellosidades Coriónicas/patología , Femenino , Humanos , Neovascularización Patológica/genética , Neovascularización Patológica/metabolismo , Embarazo , Primer Trimestre del Embarazo/genética , Primer Trimestre del Embarazo/metabolismo , Adulto Joven
8.
J Cell Biochem ; 120(3): 3898-3910, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30368882

RESUMEN

Acrylamide (ACR) is a potent neurotoxin that can be produced during high-temperature food processing, but the underlying toxicological mechanism remains unclear. In this study, the detrimental effects of ACR on the striatal dopaminergic neurons and the roles of mitogen-activated protein kinases (MAPKs) and nuclear factor κB (NF-κB) in ACR-induced neuronal apoptosis were investigated. Acute ACR exposure caused dopaminergic neurons loss and apoptosis as revealed by decreased tyrosine hydroxylase (TH)-positive cells and TH protein level and increased terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL)-positive cells in the striatum. ACR-decreased glutathione content, increased levels of malondialdehyde, proinflammatory cytokines tumor necrosis factor α, and interleukin 6. In addition, nuclear NF-κB and MAPKs signaling pathway with c-Jun N-terminal kinase (JNK) and p38 were activated by ACR. Specific inhibitors were used to explore the roles of MAPKs and NF-κB pathways in ACR-induced apoptosis in SH-SY5Y cells. Pretreatment with JNK-specific inhibitors SP600125 markedly upregulated the reduced B-cell lymphoma 2 (Bcl-2) content and downregulated the increased Bcl-2-associated X protein (Bax) level and thereby eventually reduced the proportions of early and late apoptotic cells induced by ACR, while p38 suppression by SB202190 only reversed the decrease in Bcl-2 expression. Inhibition of NF-κB by BAY 11-7082 markedly upregulated Bax level and decreased Bcl-2 expression, and eventually increasing the proportions of neuronal apoptosis compared with that in ACR alone. These results suggested that JNK contributed to ACR-induced apoptosis, while NF-κB acted as a protective regulator in response to ACR-induced neuropathy. This study helps to offer a deeper insight into the mechanism of ACR-induced neuropathy.


Asunto(s)
Acrilamida/toxicidad , Apoptosis/efectos de los fármacos , Cuerpo Estriado/efectos de los fármacos , Enfermedades de los Nervios Craneales/genética , Proteínas Quinasas Activadas por Mitógenos/genética , FN-kappa B/genética , Animales , Antracenos/farmacología , Apoptosis/genética , Línea Celular Tumoral , Cuerpo Estriado/metabolismo , Cuerpo Estriado/patología , Enfermedades de los Nervios Craneales/inducido químicamente , Enfermedades de los Nervios Craneales/metabolismo , Enfermedades de los Nervios Craneales/patología , Neuronas Dopaminérgicas/efectos de los fármacos , Neuronas Dopaminérgicas/metabolismo , Neuronas Dopaminérgicas/patología , Regulación de la Expresión Génica , Humanos , Inyecciones Intraventriculares , Interleucina-6/genética , Interleucina-6/metabolismo , Proteínas Quinasas JNK Activadas por Mitógenos/genética , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Masculino , Proteínas Quinasas Activadas por Mitógenos/metabolismo , FN-kappa B/antagonistas & inhibidores , FN-kappa B/metabolismo , Nitrilos/farmacología , Cultivo Primario de Células , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Ratas , Ratas Sprague-Dawley , Transducción de Señal , Sulfonas/farmacología , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismo , Tirosina 3-Monooxigenasa/genética , Tirosina 3-Monooxigenasa/metabolismo , Proteína X Asociada a bcl-2/genética , Proteína X Asociada a bcl-2/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/antagonistas & inhibidores , Proteínas Quinasas p38 Activadas por Mitógenos/genética , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo
9.
Brain Behav Immun ; 71: 66-80, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29704550

RESUMEN

Acrylamide (ACR) is an axonal toxicant that produces peripheral neuropathy in laboratory animals and humans. Epidemiological study found that diet ACR exposure was associated with a mild cognitive decline in men. However, limited information is available as regards its potential and underlying mechanism to cause memory alterations. Curcumin is a polyphenol with neuroprotective and cognitive-enhancing properties. In this study, we aimed to investigate the mechanism of ACR-induced spatial memory impairment and the beneficial effect of curcumin. ACR exposure at 10 mg/kg/d for 7 weeks caused slight gait abnormality and spatial memory deficits, which was associated with an activation of glial cells, a reduction of phosphorylated cAMP response elements binding protein (P-CREB) and an aggregation of hyperphosphorylated tau including p-tau (Ser262), AT8 (p-tau Ser202/Thr205) and PHF1 (p-tau Ser396/404) in the hippocampus and cortex. ACR markedly regulate the expression of glycogen synthase kinase-3ß (GSK-3ß) and cyclin-dependent kinase-5 (cdk5) to accelerate tau hyperphosphorylation. ACR inhibited the protein phosphatase 2A (PP2A) and lysosomal protease cathepsin D to decrease the p-tau dephosphorylation and degradation. The P-CREB and brain derived neurotrophic factor (BDNF) were significantly decreased by ACR. The upstream signalings of P-CREB, extracellular signal-related kinase (ERK) and Akt were markedly inhibited. The protein kinase RNA-like endoplasmic reticulum kinase (PERK) -eukaryotic initiation factor-2α (eIF2α) - activating transcription factor 4 (ATF4) signaling which negatively regulate memory processes by suppressing CREB was activated by ACR. Curcumin alleviated ACR-induced spatial memory impairment through reversing tau abnormalities and P-CREB reduction in the hippocampus. These results offered deeper insight into the mechanisms of and presented a potential new treatment for ACR-induced neurotoxicity.


Asunto(s)
Curcumina/farmacología , Memoria Espacial/efectos de los fármacos , Proteínas tau/metabolismo , Acrilamida/farmacología , Péptidos beta-Amiloides/metabolismo , Animales , Axones/metabolismo , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Catepsina D/metabolismo , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/fisiología , Quinasa 5 Dependiente de la Ciclina/metabolismo , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Hipocampo/metabolismo , Sistema de Señalización de MAP Quinasas/fisiología , Masculino , Trastornos de la Memoria/metabolismo , Neuronas/metabolismo , Fosforilación , Proteína Fosfatasa 2/metabolismo , Ratas , Ratas Sprague-Dawley , Transducción de Señal/efectos de los fármacos , Memoria Espacial/fisiología
10.
Zhongguo Zhen Jiu ; 26(7): 503-6, 2006 Jul.
Artículo en Chino | MEDLINE | ID: mdl-16903604

RESUMEN

OBJECTIVE: To observe the effect of electroacupuncture (EA) on cytokines in the cardiac surgical patient and to evaluate the application of combined acupuncture anesthesia to cardiac surgery. METHODS: Thirty patients with atrial septal defect were divided into 3 groups, general anesthesia group (A), acupuncture anesthesia group (B) and combined general anesthesia and EA group (C). Peripheral blood samples were collected before anesthesia, before cardiopulmonary bypass (CPB), 30 min after CPB and 24 h after operation to determine the levels of interferon-gamma (IFN-gamma), interleukin-2 (IL-2), IL-6 and IL-10. RESULTS: The levels of IFN-gamma and IL-2 decreased in the 3 groups after CPB and further decreased 24 h after operation, and in the group C were higher than those in the group B. The levels of IL-6 and IL-10 significantly increased 24 h after operation in the 3 groups with no significant difference among the 3 groups. CONCLUSION: The general anesthesia combined with EA can not completely improve the decrease of IFN-gamma and IL-2 induced by CPB, indicating that the good response of the general anesthesia combined with EA to stress can partially improve the immunosupression induced by CPB. Acupuncture does not have significant effect on inflammatory cytokine reaction induced by cardiac surgery.


Asunto(s)
Analgesia por Acupuntura , Procedimientos Quirúrgicos Cardíacos , Electroacupuntura , Interferón gamma/sangre , Interleucina-10/sangre , Interleucina-2/sangre , Interleucina-6/sangre , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad
11.
Am J Ther ; 3(1): 27-41, 1996 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11856995

RESUMEN

Total hip arthroplasty (THA) has provided dramatic pain relief and improvement in function for millions of patients with end-stage arthritis; however, periprosthetic osteolysis following THA has become increasingly recognized as a major clinical problem in both cemented and cementless reconstructions. An aggressive granulomatous tissue (interfacial membrane) consisting predominantly of fibroblasts, aggregates of macrophages, and foreign body giant cells develops at the interface of bone/prostheses or bone/cement. It is believed that particulate wear debris from prosthetic materials and/or bone cement are phagocytized by histiocytic cells of interfacial membrane and then these cells produce inflammatory mediators and proteolytic enzymes to provoke a cascade of osteolytic events. In this paper, we studied in vitro responsiveness of various cell types to particulate wear debris. Although titanium and titanium alloys demonstrate excellent biocompatibility in bulk from, titanium in particulate form can provoke a variety of cellular responses. We have found that small-sized Ti particles of phagocytosable size, a commonly encountered particle species in the periprosthetic tissues of failed THAs, stimulate macrophages to secrete various mediators of bone resorption (prostaglandin E(2), interleukin-1, interleukin-6, and tumor necrosis factor-alpha from macrophages and cause bone resorption in organ culture. In addition, we have shown that phagocytosable titanium particles stimulate fibroblasts to up-regulate the expression of matrix metalloproteinases (stromelysin and collagenase) without a substantial effect on the tissue inhibitor of these enzymes (TIMP). Titanium particulates also have a suppressive effect on procollagen synthesis by osteoblast-like cell line. Thus, titanium particulates have the capacity to stimulate bone resorption and inhibit bone matrix formation. In this series of experiments, we have also shown in vitro inhibitory effect of certain pharmaceutical components (indomethacin, misoprostol) upon bone resorption in organ culture, which may indicate a potential therapeutic intervention to prevent or treat particulate-induced pathological bone resorption in total joint arthroplasties.

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