Immunosuppressive and anti-inflammatory mechanisms of triptolide, the principal active diterpenoid from the Chinese medicinal herb Tripterygium wilfordii Hook. f

Triptolide exerts anti-tumor effect on oral cancer and KB cells in vitro and in vivo

Triptolide (TPL), a diterpenoid triepoxide purified from the Chinese herb Tripterygium wilfordii Hook F, has been reported to potentiate the anti-tumor effect in various cancer cells. However, the effect of TPL on oral cancers is not yet evaluated. Herein we first demonstrate that TPL induces prominent growth inhibition and apoptosis in two oral cancer cell lines, SCC25 and OEC-M1 and in KB cells. Our results indicate that TPL induces a dose-dependent apoptosis of these cells at nanomolar concentration. Apoptosis signalings are both activated through time upon TPL treatment detected by elevated caspase-3, 8, 9 activities. In xenograft tumor mouse model, TPL injection successfully inhibits the tumor growth via apoptosis induction which was demonstrated by TUNEL assay. These results demonstrate that TPL exerts anti-tumor effect on oral cancer and KB cells and suggest further the potential of TPL combining with other chemotherapeutic agents or radiotherapy for advanced oral cancer.

Caspase 3 is involved in the apoptosis induced by triptolide in HK-2 cells

Triptolide, a main active component extracted from the traditional Chinese herbal medicine, Tripterygium wilfordii Hook. f (TWHf), has been shown to possess potent immunosuppressive and anti-inflammatory properties. However, the toxicity of triptolide limits its clinical applications. Here we treated the human proximal tubular epithelial cell line HK-2 cells with triptolide in vitro and investigated its toxic effects. The cytotoxicity was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay for viability inhibition and annexin V/propidium iodide (PI) staining for apoptosis/necrosis. The activation of caspase 3 was analyzed by Western Blotting. MTT assay showed triptolide inhibited the viability of HK-2 cells in a time- and dose-dependent manner. Flow cytometry assay showed triptolide caused apoptosis rather than necrosis in HK-2 cells by staining with annexin V/PI. Furthermore, the increase of cleaved p17 fragment, an active form of caspase 3, was detected. These results suggested that triptolide is able to cause cytotoxicity on HK-2 cells, and the mechanism of which is associated with caspase 3.

Therapeutic effects of triptolide on interleukin-10 gene-deficient mice with colitis

BACKGROUND

Triptolide, the principal active ingredient in the extract of Chinese herb Tripterygium wilfordii Hook , has both anti-inflammatory and immunomodulatory activities. However, the potential therapeutic role of triptolide in IBD was still unknown. Interleukin-10 deficient mice, a well characterized experimental model of inflammatory bowel disease, spontaneously developed a Th1 T cell-mediated colitis with many similarities to Crohn's disease. This study was designed to investigate the therapeutic effect of triptolide on the chronic colitis in IL-10-/- mice.

METHODS

Triptolide was intraperitoneally administrated every another day for 8 weeks to IL-10-/- mice. The gross and histological appearances of the colon, the level of inflammatory mediators and transcription factor activation in the colon were evaluated and compared with the control group.

RESULTS

The 8-week administration of triptolide resulted in a significant decrease in the severity of colitis, together with lower production of TNF-alpha ,IFN-gamma and IL-4 in colon. The level of serum amyloid A was decreased in triptolide-treated mice. Gene expressions of IL-12 and IL-23 in colon were also downregulated after treatment. Furthermore, administration of triptolide markedly reduced NF-small ka, CyrillicB activation in colon mucosa of IL-10-/- mice.

CONCLUSIONS

The efficacy of tritpolide treatment for the reduction of intestinal inflammation in IL-10-/- mice is a result of both anti-inflammatory and immunosuppressive activity. Triptolide holds significant potential for clinical applications for CD treatment.

Triptolide Attenuates Endotoxin- and Staphylococcal Exotoxin-Induced T-Cell Proliferation and Production of Cytokines and Chemokines

Proinflammatory cytokines mediate the toxic effects of superantigenic staphylococcal exotoxins (SE) and bacterial lipopolysaccharide (LPS). Triptolide, an oxygenated diterpene derived from a traditional Chinese medicinal herb, Tripterygium wilfordii, inhibited SE-stimulated T-cell proliferation (by 98%) and expression of interleukin 1beta, interleukin 6, tumor necrosis factor, gamma interferon, monocyte chemotactic protein 1, macrophage inflammatory protein (MIP)-1alpha, and MIP-1beta by human peripheral blood mononuclear cells (PBMC). It also blocked the production of these cytokines and chemokines by LPS-stimulated PBMC in a dose-dependent manner. These results suggest that triptolide has potent immunosuppressive effects even counteracting the effects of superantigens and LPS. It also may be therapeutically useful for mitigating the pathogenic effects of these microbial products by downregulating the signaling pathways activated by both bacterial exotoxins and endotoxins.

Triptolide inhibits COX-2 expression and PGE2 release by suppressing the activity of NF-kappaB and JNK in LPS-treated microglia

Activated microglia participate in neuroinflammation which contributes to neuronal damage in neurodegenerative diseases. Inhibition of microglial activation may have potential anti-inflammatory effects. Our laboratory has previously reported that triptolide, a natural biologically active compound extracted from Tripterygium wilfordii, could protect dopaminergic neurons from inflammation-mediated damage. However, the mechanism by which triptolide inhibits inflammation remains unknown. We reported here that inhibition of prostaglandin E(2) (PGE(2)) production could be a potential mechanism of triptolide to suppress inflammation. Triptolide suppressed c-jun NH2-terminal kinase (JNK) phosphorylation, cyclooxygenase 2 (COX-2) expression and PGE(2) production in microglial cultures treated with lipopolysaccharide (LPS). Triptolide also greatly inhibited the transcriptional activity, but not the DNA-binding activity of nuclear factor-kappaB (NF-kappaB) in microglia following LPS stimulation. These results indicate that triptolide might suppress NF-kappaB activity to down-regulate COX-2 expression. The LPS-stimulated transcriptional activity of NF-kappaB was suppressed by inhibition of p38MAPK, but not by that of JNK and extracellular signal-regulated kinase. Furthermore, the LPS-induced PGE(2) production was reduced by inhibiting these kinases. Taken together, these results suggest that triptolide may suppress neuroinflammation via a mechanism that involves inactivation of two parallel signaling pathways: p38-NF-kappaB-COX-2-PGE(2) and JNK-PGE(2).

Triptolide protects against 1-methyl-4-phenyl pyridinium-induced dopaminergic neurotoxicity in rats: implication for immunosuppressive therapy in Parkinson's disease

OBJECTIVE

Neuroinflammation with microglial activation has been implicated to have a strong association with the progressive dopaminergic neuronal loss in Parkinson's disease (PD). The present study was undertaken to evaluate the activation profile of microglia in 1-methyl-4-phenyl pyridinium (MPP+)-induced hemiparkinsonian rats. Triptolide, a potent immunosuppressant and microglia inhibitor, was then examined for its efficacy in protecting dopaminergic neurons from injury and ameliorating behavioral disabilities induced by MPP+.

METHODS

The rat model of PD was established by intranigral microinjection of MPP+. At baseline and on day 1, 3, 7, 14, 21 following MPP+ injection, the degree of microglial activation was examined by detecting the immunodensity of OX-42 (microglia marker) in the substantia nigra (SN). The number of viable dopaminergic neurons was determined by measuring tyrosine hydroxylase (TH) positive neurons in the SN. Behavioral performances were evaluated by counting the number of rotations induced by apomorphine, calculating scores of forelimb akinesia and vibrissae-elicited forelimb placing asymmetry.

RESULTS

Intranigral injection of MPP+ resulted in robust activation of microglia, progressive depletion of dopaminergic neurons, and ongoing aggravation of behavioral disabilities in rats. Triptolide significantly inhibited microglial activation, partially prevented dopaminergic cells from death and improved behavioral performances.

CONCLUSION

These data demonstrated for the first time a neuroprotective effect of triptolide on dopaminergic neurons in MPP+-induced hemiparkinsonian rats. The protective effect of triptolide may, at least partially, be related to the inhibition of MPP+-induced microglial activation. Our results lend strong support to the use of immunosuppressive agents in the management of PD.

Triptolide-induced transcriptional arrest is associated with changes in nuclear substructure

Triptolide, an active component of the medicinal herb lei gong teng, is a potent anticancer and anti-inflammatory therapeutic. It potently inhibits nuclear factor-kappaB transcriptional activation after DNA binding, although a precise mechanism is as yet unknown. Here, we report that triptolide also induces distinct nuclear substructural changes in HeLa cells. These changes in the nucleolus and nuclear speckles are reversible and dependent on both time and concentration. Furthermore, nuclear changes occurred within hours of triptolide treatment and were calcium and caspase independent. Rounding of nuclear speckles, an indication of transcriptional arrest, was evident and was associated with a decrease in RNA polymerase II (RNA Pol II) COOH-terminal domain Ser(2) phosphorylation. Additionally, the nucleolus disassembled and RNA Pol I activity declined after RNA Pol II inhibition. We therefore conclude that triptolide causes global transcriptional arrest as evidenced by inactivity of RNA Pol I and II and the subsequent alteration in nuclear substructure.

Mycophenolate mofetil and triptolide alleviating airway inflammation in asthmatic model mice partly by inhibiting bone marrow eosinophilopoiesis

The bone marrow eosinophilopoiesis makes a major contribution to the chronic airway inflammation in asthmatic animals and patients. Some anti-asthmatic medicines alleviated the asthmatic airway inflammation by inhibiting the bone marrow eosinophilopoiesis. Immunosuppressive agents have been commonly used in patients with glucocorticoid refractory asthma and have been proved to be effective. However, the research on the effect of the immunosuppressive agents on the bone marrow eosinophilopoiesis has seldom been reported. The purpose of the study was to explore the effect of mycophenolate mofetil (MMF) and triptolide (TP) on the bone marrow eosinophilopoiesis and to further investigate the mechanisms of the immunosuppressive agents involved in the anti-asthmatic effect. Balb/c mice were sensitized and challenged by OVA to establish the asthmatic model, and respectively administered orally with sterile saline, MMF, and TP once daily for 2 weeks. Airway inflammation, and inflammatory mediators IL-5 and eotaxin in the peripheral blood and bone marrow were measured by histology and ELISA. Immunocytochemistry combined with in situ hybridization technique and Western blot analysis was performed to estimate the amount of CD34+ IL-5R mRNA+ cells and IL-5R expression in the bone marrow. The count of new produced eosinophils in the bone marrow was detected by anti-BrdU immunocytochemistry. We found that MMF and TP attenuated OVA-induced eosinophil (EOS) recruitment in bronchoalveolar lavage fluid (BALF), inflammatory mediator expression of IL-5 and eotaxin in the peripheral blood, inflammatory cells expressing eotaxin in the lung tissues and the number of new produced EOS in the bone marrow. Also, MMF abated the migration of CD34+ cells from the bone marrow to the peripheral blood, which was associated with a decreased eotaxin expression in the bone marrow and a decreased CCR3 expression on bone marrow cells. While, MMF or TP failed to decrease the amount of CD34+ IL-5R mRNA+ cells (EOS progenitors), and IL-5R expression in the bone marrow of asthmatic model mice. These results demonstrated that MMF and TP reduce the eosinophilopoiesis of the bone marrow; this is associated with a decrease of IL-5 produced by T cells, which contribute to alleviate the allergic airway inflammation in asthma. In addition, MMF decreased the CD34+ cells migration from the bone marrow to the peripheral blood by the reduction of the level of eotaxin in the bone marrow and the expression of CCR3 on the bone marrow cells.

Therapeutic strategies for Parkinson's disease: the ancient meets the future--traditional Chinese herbal medicine, electroacupuncture, gene therapy and stem cells

In China, it has been estimated that there are more than 2.0 million people suffering from Parkinson's disease, which is currently becoming one of the most common chronic neurodegenerative disorders during recent years. For many years, scientists have struggled to find new therapeutic approaches for this disease. Since 1994, our research group led by Drs. Ji-Sheng Han and Xiao-Min Wang of Neuroscience Research Institute, Peking University has developed several prospective treatment strategies for the disease. These studies cover the traditional Chinese medicine-herbal formula or acupuncture, and modern technologies such as gene therapy or stem cell replacement therapy, and have achieved some original results. It hopes that these data may be beneficial for the research development and for the future clinical utility for treatment of Parkinson's disease.

Combined treatment with triptolide and rapamycin prolongs graft survival in a mouse model of cardiac transplantation

Current immunosuppressive strategies for transplantation have failed to achieve long-term graft survival. In this study, we investigate the effects of combined treatment with triptolide (TPT) and rapamycin (Rapa) on graft survival as well as changes in pathology and immunological responses. Heterotopic heart transplantation was performed. TPT and Rapa were administered either alone or in combination. The mean survival time (MST) for the cardiac allografts in animals receiving the combination of TPT and Rapa was 93.5 +/- 6.7 days compared to treatment with TPT (MST: 23.5 +/- 5.3 days), Rapa (22 +/- 1.3 days) alone or no treatment (7.66 +/- 0.8 days). Histopathological evaluation showed that inflammatory cell infiltration was markedly reduced in grafts with combined treatment groups. Down-regulation of CCL19, CCR5, CCR7, interferon gamma and interleukin (IL)-12 in the combination treatment was accompanied by increased expression of IL-4, IL-10 and CD4(+)CD25(+)Foxp3(+) regulatory T (Tr) cells in spleen. Finally, dendritic cell (DC) maturation was impaired by treatment with TPT/Rapa. Our results demonstrate that combination therapy with TPT and Rapa markedly prolongs cardiac allograft survival. This effect is accompanied by inhibition of DCs maturation, conditioning DCs to adopt tolerogenic phenotype, and the expansion of Tr cells. These results add weight to the application of combination therapy in transplantation.

Honeybee (Apis cerana) foraging responses to the toxic honey of Tripterygium hypoglaucum (Celastraceae): changing threshold of nectar acceptability

To investigate honeybee foraging responses to toxic nectar, honey was collected from Apis cerana colonies in the Yaoan county of Yunnan Province, China, during June, when flowers of Tripterygium hypoglaucum were the main nectar source available. Pollen analysis confirmed the origin of the honey, and high-performance liquid chromatography showed the prominent component triptolide to be present at a concentration of 0.61 mug/g +/- 0.11 SD. In cage tests that used young adult worker bees, significantly more of those provided with a diet of T. hypoglaucum honey mixed with sugar powder (1:1) died within 6 d (68.3%) compared to control groups provided with normal honey mixed with sugar powder (15.8%). Honeybees were trained to visit feeders that contained honey of T. hypoglaucum (toxic honey) as the test group and honey of Vicia sativa or Elsholtzia ciliata as control groups (all honeys diluted 1:3 with water). Bees preferred the feeders with normal honey to those with toxic honey, as shown by significantly higher visiting frequencies and longer imbibition times. However, when the feeder of normal honey was removed, leaving only honey of T. hypoglaucum, the foraging bees returned to the toxic honey after a few seconds of hesitation, and both visiting frequency and imbibition time increased to values previously recorded for normal honey. Toxic honey thus became acceptable to the bees in the absence of other nectar sources.

Molecular understanding and modern application of traditional medicines: triumphs and trials

Traditional medicines provide fertile ground for modern drug development, but first they must pass along a pathway of discovery, isolation, and mechanistic studies before eventual deployment in the clinic. Here, we highlight the challenges along this route, focusing on the compounds artemisinin, triptolide, celastrol, capsaicin, and curcumin.

Triptolide is a traditional Chinese medicine-derived inhibitor of polycystic kidney disease

During kidney organogenesis, tubular epithelial cells proliferate until a functional tubule is formed as sensed by cilia bending in response to fluid flow. This flow-induced ciliary mechanosensation opens the calcium (Ca(2+)) channel polycystin-2 (PC2), resulting in a calcium flux-mediated cell cycle arrest. Loss or mutation of either PC2 or its regulatory protein polycystin-1 (PC1) results in autosomal dominant polycystic kidney disease (ADPKD), characterized by cyst formation and growth and often leading to renal failure and death. Here we show that triptolide, the active diterpene in the traditional Chinese medicine Lei Gong Teng, induces Ca(2+) release by a PC2-dependent mechanism. Furthermore, in a murine model of ADPKD, triptolide arrests cellular proliferation and attenuates overall cyst formation by restoring Ca(2+) signaling in these cells. We anticipate that small molecule induction of PC2-dependent calcium release is likely to be a valid therapeutic strategy for ADPKD.

Anti-Inflammatory Bioactivities in Plant Extracts

The medical ethnobotanical knowledge propagated over generations in the coastal regions of the Eastern Mediterranean, including Lebanon, is one that has built on several ancient cultures and civilizations of these regions. Recent interest in medical ethnobotany and the use of medicinal herbs in treating or preventing ailments has rejuvenated interest in folk medicine practices, especially those transcendent across generations. According to Eastern Mediterranean folk medicine practices, herbal remedies that treat many inflammation-related ailments were typically based on plant bioactive water extracts or decoctions. Studies have shown that active anti-inflammatory ingredients in water extracts include many natural chemicals such as phenols, alkaloids, glycosides, and carbohydrates. The intent of this manuscript is twofold: first, to review the literature that describes anti-inflammatory bioactivities in plant extracts of different plant genera; and second, to evaluate indigenous folk remedies used by folk doctors to treat inflammatory ailments in this region of the world. For this aim, the reported literature of five plant genera assumed to possess anti-inflammatory bioactivities and typically prescribed by folk doctors to treat inflammation-related ailments is reviewed.

Triptolide impairs dendritic cell migration by inhibiting CCR7 and COX-2 expression through PI3-K/Akt and NF-kappaB pathways

Inhibition of dendritic cell (DC) migration into tissues and secondary lymphoid organs is an efficient way to induce immunosuppression and tolerance. CCR7 and PGE(2) are critical for DC migration to secondary lymphoid organs where DC initiate immune response. Triptolide, an active component purified from the medicinal plant Tripterygium Wilfordii Hook F., is a potent immunosuppressive drug capable of prolonging allograft survival in organ transplantation by inhibiting T cell activation and proliferation. Considering the essential role in T cell tolerance of DC migration to secondary lymphoid organs, here we demonstrate that triptolide can significantly inhibit LPS-triggered upregulation of CCR7 expression and PGE(2) production by inhibiting cyclooxygenase-2 (COX-2) expression in DC, thus impairing DC migration towards CCR7 ligand CCL19/MIP-3betain vitro. Moreover, triptolide-treated DC display impaired migration into secondary lymphoid organs and in vivo administration of triptolide also inhibits DC migration. Further studies show that the triptolide-mediated inhibitory effects of LPS-induced activation of phosphatidylinositol-3 kinase (PI3-K)/Akt and nuclear NF-kappaB activation are involved in down-regulation of COX-2 and CCR7 expression resulting in impaired migration to secondary lymphoid organs of DC. Therefore, inhibition of DC migration through decreasing COX-2 and CCR7 expression via PI3-K/Akt and NF-kappaB signal pathways provides additional mechanistic explanation for triptolide's immunosuppressive effect.

Triptolide, a diterpenoid triepoxide, suppresses inflammation and cartilage destruction in collagen-induced arthritis mice

Chinese herbal remedy Tripterygium wilfordii Hook. f. (TWHF) has been reported to be therapeutically efficacious in the treatment of rheumatoid arthritis (RA), but its in vivo actions have not been clarified. The purpose of this study was to investigate the effects of triptolide, a diterpenoid triepoxide extracted from TWHF, on inflammation and cartilage destruction in collagen-induced arthritis (CIA) model mice. Histological examination demonstrated that triptolide significantly reduced the inflammatory responses and cartilage damage in the joint tissues. Interestingly, triptolide interfered with CIA-augmented expression of matrix metalloproteinases-13 and -3, which are considered to be key enzymes in the pathological destruction of cartilage, and simultaneously augmented CIA-reduced tissue inhibitors of metalloproteinases-1 and -2 expression in the joints. Moreover, triptolide inhibited prostaglandin E(2) production via selective suppression of the production and gene expression of cyclooxygenase (COX)-2, but not COX-1. The levels of interleukin (IL)-1beta, tumor necrosis factor alpha and IL-6 were also decreased by triptolide in the joint tissues and sera as well as the suppression of CIA-mediated expression of their mRNAs in the joints. In addition, triptolide treatment in vivo was able to reduce an abundance of nuclear factor-kappaB, the transcriptional factor closely related to the inflammatory process, in articular cartilage and synovium in CIA mice. These results suggest that triptolide exerts novel chondroprotective and anti-inflammatory effects on RA, and the therapeutic action of TWHF on RA is, in part, due to the triptolide activities.

The dihydro-β-agarofuran sesquiterpenoids

Dihydro-Beta-agarofuran sesquiterpenoids are a structurally diverse class of natural products based on tricyclic 5,11-epoxy-5Beta,10alpha-eudesman-4-(14)-ene skeleton. Between January 1990 and June 2006, 462 new dihydro-Beta-agarofuran sesquiterpenoids of 74 structural types have been isolated from about 64 species of Celastraceae, 3 species of Hippocrateaceae and one species of Lamiaceae. The present review covers the chemical and biological activity research of dihydro-Beta-agarofuran sesquiterpenoids in the past 16 years. The chemical research includes structural classification into sesquiterpene polyesters and macrolide sesquiterpene pyridine alkaloids, synthesis of dihydro-Beta-agarofuran as well as extraction, isolation and purification methods. The biological activity research includes activities such as multidrug resistance (MDR) reversal activity, HIV inhibition, cytotoxicity, antitumor activity, antifeedant activity and insecticidal activity with some insights to their modes of actions.

Pharmacokinetic Study of Triptolide, a Constituent of Immunosuppressive Chinese Herb Medicine, in Rats

Triptolide is a potential anti-immune agent, and has shown multi-organic toxicity, however its toxic mechanism remained undiscovered. This paper aimed at characterizing the pharmacokinetic profiles of triptolide in rats to provide the clue to approach the toxic mechanism. The absorption, distribution, metabolism and excretion of triptolide were investigated in male Sprague-Dawley rats after single doses of oral and i.v. administration. After oral administration of 0.6, 1.2 and 2.4 mg/kg, the concentration of triptolide in plasma reached the maximum within 15 min, and declined rapidly with an elimination half-life from 16.81 to 21.70 min. The triptolide kinetics was fitted into one-compartment model after i.v. administration. Oral absolute bioavailability was 72.08% at the dose of 0.6 mg/kg. Triptolide was also rapidly distributed and eliminated in all selected tissues. Less than 1% triptolide of the dose was recovered from the bile, urine or feces as parent drug within 48 h. While triptolide could not be detected in tissues and plasma at 4 h post dose, rats in the group C (oral: 1.2 mg/kg) and D (oral: 2.4 mg/kg) showed obvious toxic response to triptolide and some of rats even died out. It was indicated that triptolide was metabolized extensively, eliminated rapidly, and also showed that the toxicity produced by the triptolide was lag behind the exposure concentration.

Triptolide inhibits CC chemokines expressed in rat adjuvant-induced arthritis

Triptolide, a diterpenoid triepoxide from Tripterygium wilfordii Hook F (TWHF), has been proven to have potent immunosuppressive and anti-inflammatory activities. It has been clinically used to treat patients with rheumatoid arthritis (RA), in which chemokines play an important role in immune and inflammatory responses. To investigate the effect of triptolide on MCP-1, MIP-1alpha and RANTES, we used complete Freund's adjuvant to induce adjuvant-induced arthritis (AA) in rats. AA in rat is a useful experimental model of human RA. Our data show that the thickness of arthritic ankle decreases with administration of triptolide. Both mRNA and protein levels of MCP-1, MIP-1alpha and RANTES in synovial tissue of rats with AA are significantly higher than those in normal rats. mRNA levels of MIP-1alpha and RANTES increase in peripheral blood mononuclear cells of rats with AA in comparison with those in normal rats, whereas no MCP-1 mRNA can be detected. Triptolide can significantly inhibit rat AA induced over-expression of MCP-1, MIP-1alpha and RANTES at both mRNA and protein levels in a dose-dependent manner. These results may contribute to the therapeutic effects of triptolide in rheumatoid arthritis.

Triptolide induces Bcl-2 cleavage and mitochondria dependent apoptosis in p53-deficient HL-60 cells

Triptolide, a bioactive component of the Chinese medicinal herb Tripterygium wilfordii Hook F., induces p53-mediated apoptosis in cancer cells. This study demonstrated that triptolide activated an alternative p53-independent apoptotic pathway in HL-60 cells. In the absence of an intact p53 and without changing Bax level, at nM range triptolide induced apoptosis with concomitant DNA fragmentation, S phase cell cycle arrest, mitochondrial cytochrome c release and the activation of caspases. Besides, both caspases 8 and 9 were activated and the simultaneous inhibition of both was required to completely block triptolide's apoptotic effect. Importantly, triptolide induced the appearance of a truncated 23kD Bcl-2 which was inhibited by the general caspase inhibitor Z-VAD-FMK. In the MCF-7 cells that possessed the wild type p53 but lacked caspases 3, triptolide induced cell death with an increase in p53 but Bcl-2 remained unaltered. On the other hand, transfected cells overexpressing the 28kD Bcl-2 became more resistant to triptolide and upon triptolide treatment accumulated in the G(1) instead of S phase. After 36h treatment, triptolide activated JNK pathways, at the same time inactivated the ERK and p38 pathways. However, SP600125, a specific JNK inhibitor, could not inhibit the triptolide-mediated cleavage of caspase 3, indicated that activation of JNK might not be related to the apoptotic effects of triptolide. Our data suggest that in the absence of an intact p53 and without altering Bax level triptolide induces apoptosis activates a positive amplification loop involving caspase-mediated Bcl-2 cleavage/activation, mitochondrial cytochrome c release and further activation of caspases.

(5R)-5-hydroxytriptolide attenuated collagen-induced arthritis in DBA/1 mice via suppressing interferon-gamma production and its related signaling

(5R)-5-Hydroxytriptolide (LLDT-8) displays strong immunosuppressive activities both in vitro and in vivo in our previous studies. This study aims to investigate whether LLDT-8 has antiarthritic potential in a murine model of type II bovine collagen (CII)-induced arthritis (CIA) and to show the mechanism(s) of LLDT-8 action. DBA/1 mice were immunized with CII to induce arthritis and administered with LLDT-8. The severity of arthritis was evaluated according to the clinical score and joint damage. The effects of LLDT-8 on immune responses were determined by measurement of serum antibody levels, lymphocyte proliferation assay, cytokine assay, nitric oxide (NO) production, arginase activity assays, fluorescence-activated cell sorting analysis of splenic Mac-1+ cells, as well as polymerase chain reaction analysis for interferon-gamma (IFN-gamma)-related gene expression. We showed that LLDT-8 treatment significantly reduced the incidence and severity of CIA. The preventive and therapeutic effects of LLDT-8 are associated with 1) reduction of serum anti-CII immunoglobulin (Ig) G, IgG2a, and IgG1 levels; 2) inhibition of CII-specific lymphocyte proliferation, IFN-gamma and interleukin-2 production; 3) blockade of gene expressions in IFN-gamma signaling, including IFN-gamma production pathways [signal transducer and activator of transcription (STAT) 1, T-box transcription factor, interleukin 12Rbeta2, and STAT4] and IFN-gamma-induced chemokine transcription [macrophage inflammatory protein (Mip)-1alpha, Mip-1beta, regulated on activation normally T cell expressed and secreted, and inducible protein 10]; and 4) retardation of the abnormal increase of NO via IFN-gamma/STAT1/interferon regulatory factor 1/inducible nitric-oxide synthase pathway and arginase activity. Moreover, the mRNA transcription of chemokine receptors was also suppressed [including C-C chemokine receptor (CCR) 1, CCR5, and C-X-C chemokine receptor 3]. In conclusion, our data suggest that the antiarthritic effect of LLDT-8 is closely related to the blockade of IFN-gamma signaling. LLDT-8 may have a therapeutic value in the treatment of rheumatoid arthritis.

(5R)-5-Hydroxytriptolide (LLDT-8), a novel triptolide derivative, prevents experimental autoimmune encephalomyelitis via inhibiting T cell activation

A novel triptolide derivative (5R)-5-hydroxytriptolide (LLDT-8) has been shown to have potent immunosuppressive activities. Here LLDT-8 was evaluated in experimental autoimmune encephalomyelitis (EAE), the model of multiple sclerosis (MS). LLDT-8 reduced the incidence and severity of EAE, which was associated with the inhibition of the MOG 35-55 lymphocyte recall response, anti-MOG 35-55 T cell responses, interleukin (IL)-2 and interferon (IFN)-gamma production. In vitro, LLDT-8 inhibited primary T cells proliferation, division, IL-2 and IFN-gamma production stimulated with anti-CD3/28. These findings highlight the fact that LLDT-8 prevents EAE by suppressing T cell proliferation and activation, with a potential for treatment of MS.

Inhibitory effects of Triptolide on interferon-gamma-induced human leucocyte antigen-DR, intercellular adhesion molecule-1, CD40 expression on retro-ocular fibroblasts derived from patients with Graves' ophthalmopathy

PURPOSE

To explore the effects of Triptolide, the principal active diterpenoid from the Chinese Medicinal Herb Tripterygium Wilfordii Hook F that has immunosuppressive and anti-inflammatory properties, on cell proliferation, hyaluronic acid (HA) synthesis, and the expressions of human leucocyte antigen-DR (HLA-DR), intercellular adhesion molecule-1 (ICAM-1) and CD40 on cultured retro-ocular fibroblasts (RFs) from patients with Graves' ophthalmopathy.

METHODS

After two to five passages, cultured RFs were incubated for 48 h within a medium alone or in the presence of recombinant human interferon-gamma (IFN-gamma) and various concentrations of Triptolide. Cell viability was assessed by MTT (3-[4.5-dimethylahiazol-2-yl]-2,5-diphenyltetrazolium Bromide). RFs proliferation was assessed by [(3)H]-thymidine incorporation assay. Flow cytometry was used to investigate the amount of HLA-DR, ICAM-1 and CD40. HA synthesis was measured by radioimmunoassay.

RESULTS

Cell viability was not detrimentally affected when incubated with Triptolide from 0.01 microg/L to 10 microg/L for 48 h, and decreased with 20 microg/L Triptolide. The incorporation of [(3)H]-thymidine of RFs was 55 476 +/- 15 842 cpm incubated with medium alone or 18 352 +/- 3568 cpm with 10 microg/L Triptolide (t = 5.600, P < 0.01). Initially, the percentage of positive cells of HLA-DR, ICAM-1 and CD40 on RFs were 4.75 +/- 2.13%, 17.53 +/- 10.12% and 6.38 +/- 2.23%, respectively, and the synthesis of HA was 100 +/- 12%. Compared with basal values, 48-h incubation with IFN-gamma (100 U/mL) significantly enhanced the amount of HLA-DR, ICAM-1 and CD40, and HA synthesis. The values were 60.58 +/- 10.12% (t = 13.224, P < 0.01), 62.66 +/- 18.17% (t = 5.315, P < 0.01), 57.67 +/- 13.61% (t = 9.110, P < 0.01) and 164 +/- 22% (t = 9.238, P < 0.01), respectively. Triptolide 0.01 microg/L had little effect on IFN-gamma-induced HLA-DR, ICAM-1 and CD40 amounts, as well as HA synthesis. When the concentration ranged from 0.1 microg/L to 10 microg/L, Triptolide inhibited IFN-gamma-induced RFs activation in a dose-dependent manner. It was also found that Triptolide had the same inhibiting effects on IFN-gamma-induced RFs and skin fibroblasts from patients with normal individual conditions.

CONCLUSIONS

Triptolide could inhibit IFN-gamma-induced activation of RFs derived from patients with Graves' ophthalmopathy.

Preventive effects of (5R)-5-hydroxytriptolide on concanavalin A-induced hepatitis

(5R)-5-hydroxytriptolide (LLDT-8) exhibits strong immunosuppressive activities in vitro and in vivo. Here, we investigated the effects of LLDT-8 on concanavalin A-induced hepatitis. Liver damage was evaluated by serum alanine transaminase (ALT) level and liver histology. The effects of LLDT-8 were determined by measurement of serum cytokines, lymphocyte proliferation assay, flow cytometry analysis of splenic T cell percentage and apoptosis, reverse-transcription polymerase chain reaction (RT-PCR) analysis for gene transcriptions. In LLDT-8-treated mice, serum ALT level and histological damage were markedly attenuated. The beneficial effect of LLDT-8 was closely associated with (i) reduction of serum tumor necrosis factor-alpha, interferon-gamma (IFN-gamma), interleukin-2, interleukin-12, and interleukin-6 levels; (ii) elimination of activated T cells by increasing proapoptotic genes signal transducer and activator of transcription 1 (STAT1) and interferon regulatory factor-1 (IRF-1) expression in spleens; (iii) blockade of mRNA expressions for chemokines (monokine induced by IFN-gamma, Mig; IFN-gamma-inducible protein-10, IP-10; IFN-inducible T cell-alpha chemoattractant, I-TAC), vascular adhesion molecule-1 (VCAM-1), and chemokine receptors (C-C chemokine receptor 1, CCR1; C-C chemokine receptor 5, CCR5; C-X-C chemokine receptor 3, CXCR3) in livers. These results suggested the therapeutic potential of LLDT-8 in IFN-gamma/STAT1/IRF-1 signaling- and inflammatory cytokines-mediated immune disorders.

Studies on calcium dependence reveal multiple modes of action for triptolide

Triptolide, a diterpene triepoxide isolated from the traditional Chinese medicinal vine Trypterygium wilfordii hook f., has been shown to induce rapid apoptosis in a myriad of cancer cell lines and inhibit NFkappaB transactivation. To understand further the general cellular mechanisms for this therapeutically relevant natural product, binding and biological activities were assessed. Studies showed that triptolide binding was saturable, reversible, and primarily localized to cell membranes. Depletion of calcium enhanced overall binding while differentially modulating biological function. Furthermore, triptolide's structural moieties demonstrated variability in the regulation of cell death versus inhibition of NFkappaB transactivation. These results implicate triptolide in the manipulation of at least two distinct cellular pathways with differing requirements for calcium and effective triptolide concentration in order to elicit each particular biological function.

The treatment of relapsing primary nephrotic syndrome in children

OBJECTIVE

To explore better therapy and reduce the rate of re-relapse of primary nephritic syndrome in children who had been treated with corticosteroids but relapsed.

METHODS

Eighty relapsers were enrolled from Jan. 1994 to Apr. 2000, who were randomly divided into two groups. The treatment group (n=39) had been treated with tripterysium glucosides for three months, with the control group (n=41) members were treated with cyclophosphmide (CTX) by intermission intravenous pulse, with total dose of CTX not being more than 150 mg/kg. Prednisone, meanwhile, was given to both groups. The total treatment period of prednisone was prolonged by 12-18 months.

RESULTS

After following up for 3-7 years, the re-relapse rates of both groups were observed. The re-relapse rate of the treatment group was 28.2% to 29.3% in the CTX-controlled group. The re-relapse rates between two groups were almost similar, and with no observed significant difference (P>0.05). The side effect of tripterysium glucosides was less than that of CTX.

CONCLUSION

For the treatment of relapsing nephritic syndrome in children, the combination of tripterysium glucosides and prolonged corticosteroid therapy is as effective as the regimen of CTX plus prolonged use of prednisone.

Triptolide affects the differentiation, maturation and function of human dendritic cells

Triptolide is a purified component from a traditional Chinese herb Tripterygium wilfordii Hook F. It has been shown to have anti-inflammatory and immunosuppressive activities by its inhibitory effect on T cells. But the effect of triptolide on dendritic cells (DC) is unknown. Dexamethasone (Dex) is a classic immunosuppressive agent known to suppress the immune response at different levels and has recently found to modulate the development of DC, thereby influencing the initiation of the immune response. In this study, we investigated the affect of triptolide on the differentiation, maturation and function of DC differentiated from human monocytes (MoDC) in vitro in the presence of GM-CSF and IL-4. Dex was included in the study as a reference. Our data show that both triptolide and Dex prevented the differentiation in immature MoDC by inhibiting CD1a, CD40, CD80, CD86 and HLA-DR expression but upregulating CD14 expression, as well as by reducing the capacity of MoDC to stimulate lymphocyte proliferation in the allogeneic mixed lymphocyte reaction. They blocked the maturation of MoDC as totally blocked induction of CD83 expression and absent upregulation of CD40, CD80, CD86 and HLA-DR. In addition, higher concentration of triptolide (20 ng/ml) and 10(-6) M Dex induced apoptosis in MoDC as measured by expression of APO2*7 and DNA fragmentation (TUNEL assay). However, the phagocytic capacity of MoDC was enhanced by triptolide but not Dex. Therefore, the suppression of DC differentiation, the function in immature DCs as well as the inhibition of DC maturation by triptolide may explain some of its immunosuppressive properties. It is suggested that DCs are a primary target of the immunosuppressive activity of triptolide.

The effect of triptolide on CD4+ and CD8+ cells in Peyer's patch of SD rats with collagen induced arthritis

Triptolide is a purified component from a traditional Chinese herb Tripterygium wilfordii Hook F. It has been shown to have anti-inflammatory and immunosuppressive activities by its inhibitory effect on T cells. But the effect of triptolide on Peyer's patch cells is unknown. Enteric mucosal immune system, including Peyer's patch, is regarded as one of the sites for inducing immunity tolerance, and this intolerance effect has been used to induce oral tolerance which can considerably reduce arthritis severity in several models of experimental polyarthritis and RA patients. In this study, we investigated the effect of triptolide on the Peyer's patch cells and peripheral lymphocytes in collagen induced arthritis (CIA) in rats. CIA in rat is a widely studied animal model of inflammatory polyarthritis with similarities to rheumatoid arthritis (RA). Our data show that triptolide could lower the arthritic scores and delay the onset of CIA. There are more Peyer's patches in triptolide treated rats than in control rats, while there is no difference in Peyer's patch numbers between CIA rats and triptolide treated rats. In the Peyer's patch, more CD4+ cells are observed in CIA rats, and the numbers of CD4+ cells in triptolide treated rats and control rats are similar. While more CD8+ cells are observed in triptolide treated rats, and the numbers of CD8+ cells in CIA rats and control rats are similar. In periphery, more CD4+ cells and less CD4+ cells in CIA rats and triptolide treated rats are respectively observed. Therefore, the regulation on Peyer's patch might explain some of the immunosuppressive activities of triptolide, and enteric immune response might be actively involved in CIA pathogenesis. It is suggested that the Peyer's patch is one of the primary targets of the immunosuppressive activity of triptolide.

Biological basis for the use of botanicals in osteoarthritis and rheumatoid arthritis: a review

Osteoarthritis (OA) of the knee and hip is a debilitating disease affecting more women than men and the risk of developing OA increases precipitously with aging. Rheumatoid arthritis (RA), the most common form of inflammatory joint diseases, is a disease of unknown etiology and affects approximately 1% of the population worldwide, and unlike OA, generally involves many joints because of the systemic nature of the disease. Non-steroidal anti-inflammatory drugs (NSAIDs) are the first drugs of choice for the symptomatic treatment of both OA and RA. Because of the risks associated with the use of NSAIDs and other limitations, the use of alternative therapies, such as acupuncture and medicinal herbs, is on the rise and according to reports approximately 60-90% of dissatisfied arthritis patients are likely to seek the option of complementary and alternative medicine (CAM). This paper reviews the efficacy of some of the common herbs that have a history of human use and their anti-inflammatory or antiarthritic properties have been evaluated in animal models of inflammatory arthritis, in studies employing well defined and widely accepted in vitro models that use human chondrocytes/cartilage explants or in clinical trials. Available data suggests that the extracts of most of these herbs or compounds derived from them may provide a safe and effective adjunctive therapeutic approach for the treatment of OA and RA. This, in turn, argues for trials to establish efficacy and optimum dosage of these compounds for treating human inflammatory and degenerative joint diseases.

Triptolide, a constituent of immunosuppressive Chinese herbal medicine, is a potent suppressor of dendritic-cell maturation and trafficking

Triptolide (TPT) is a chemically defined, potent immunosuppressive compound isolated from an anti-inflammatory Chinese herbal medicine. TPT has been reported to inhibit autoimmunity, allograft rejection, and graft-versus-host disease (GVHD), and its efficacy was previously attributed to the suppression of T cells. Since dendritic cells (DCs) play a major role in the initiation of T-cell-mediated immunity, we studied the effects of TPT on the phenotype, function, and migration of human monocyte-derived DCs. TPT treatment, over a pharmacologic concentration range, inhibited the lipopolysaccharide (LPS)-induced phenotypic changes, characteristic of mature DCs and the production of interleukin-12p70 (IL-12p70). Consequently, the allostimulatory functions of DCs were impaired by TPT treatment. Furthermore, the calcium mobilization and chemotactic responses of LPS-stimulated DCs to secondary lymphoid tissue chemokine (SLC)/CC chemokine ligand 21 (CCL21) were significantly lower in TPT-treated than untreated DCs, in association with lower chemokine receptor 7 (CCR7) and higher CCR5 expression. Egress of Langerhans cells (LCs) from explanted mouse skin in response to macrophage inflammatory protein-3beta (MIP-3beta)/CCL19 was arrested by TPT. In vivo administration of TPT markedly inhibited hapten (fluorescein isothiocyanate [FITC])-stimulated migration of mouse skin LCs to the draining lymph nodes. These data provide new insight into the mechanism of action of TPT and indicate that the inhibition of maturation and trafficking of DCs by TPT contributes to its immunosuppressive effects.

Triptolide protects dopaminergic neurons from inflammation-mediated damage induced by lipopolysaccharide intranigral injection

Converging lines of evidence suggest that neuroinflammatory processes may account for the progressive death of dopaminergic neurons in Parkinson's disease (PD). Therefore, anti-inflammatory strategies have attracted much interest for their potential to prevent further deterioration of PD. Our previous study showed that triptolide, a traditional Chinese herbal compound with anti-inflammatory and immunosuppressive properties, protected dopaminergic neurons from lipopolysaccharide (LPS)-induced damage in primary embryonic midbrain cell cultures. To examine further if triptolide can protect dopaminergic neurons from inflammation-mediated damage in vivo, microglial activation and injury of dopaminergic neurons were induced by LPS intranigral injection, and the effects of triptolide treatment on microglial activation and survival ratio and function of dopaminergic neurons were investigated. Our results demonstrated that microglial activation induced by a single intranigral dose of 10 mug of LPS reduced the survival ratio of tyrosine hydroxylase-immunoreactive (TH-ir) neurons in the substantia nigra pars compacta (SNpc) to 29% and the content of dopamine (DA) in striatum to 37% of the non-injected side. Intriguingly, treatment with triptolide of 5 mug/kg for 24 days once per day dramatically improved the survival rate of TH-ir neurons in the SNpc to 79% of the non-injected side. Meanwhile, treatment with triptolide of 1 or 5 mug/kg for 24 days once per day significantly improved DA level in striatum to 70% and 68% of the non-injected side, respectively. Complement receptor 3 (CR3) immunohistochemical staining revealed that triptolide treatment potently inhibited LPS-elicited deleterious activation of microglia in SNpc. The excessive production of cytokines, such as tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta, was significantly abolished by triptolide administration. These results, together with our previous data in vitro, highly suggest the effectiveness of triptolide in protecting dopaminergic neurons against inflammatory challenge.

Multi-glycoside of Tripterygium wilfordii Hook f. ameliorates proteinuria and acute mesangial injury induced by anti-Thy1.1 monoclonal antibody

BACKGROUND/AIMS

Multi-glycoside from Tripterygium wilfordii Hook f. (GTW) is used for various immune and inflammatory diseases including renal diseases represented by mesangial proliferative glomerulonephritis (MsPGN) in China. However, there have been no fundamental studies on the operating mechanism of GTW on MsPGN. The aim of this study is to examine as the first step the effects of GTW on acute injurious process such as mesangial injury and proteinuria in an acute and reversible Thy.1.1 glomerulonephritis (Thy1.1GN) model and then to clarify the action mechanism of GTW at molecular level by examining its effects on various injurious factors in this model.

METHODS

Thy1.1 GN was induced in rats by a single intravenous injection with 500 microg of anti-Thy1.1 mAb 1-22-3. Daily oral administration of GTW and vehicle as a control was started from 3 days before injection of mAb to the day of sacrifice in each experiment. Fourteen rats were randomly divided into 2 groups, GTW-treated and vehicle-treated groups, and sacrificed on day 14 in experiment 1 or on day 7 in experiment 2 after induction of Thy1.1 GN. Proteinuria was determined on days 1, 3, 5, 7, 10 and 14 in experiment 1 or on 1, 3, 5 and 7 in experiment 2. From blood and kidneys taken at sacrifice, blood biochemical parameters, mesangial morphological changes, glomerular macrophage infiltration, and glomerular mRNA expression of cytokines were examined.

RESULTS

In experiment 1, proteinuria and mesangial matrix expansion were significantly attenuated by GTW treatment. In experiment 2, GTW treatment significantly ameliorated proteinuria, mesangial lesions and macrophage accumulation in glomerulus. In addition, it significantly reduced the glomerular expression of mRNA for PDGF, MCP-1 and IL-2.

CONCLUSION

GTW ameliorated not only proteinuria but also mesangial alterations in Thy1.1 GN most likely by reducing expression of injurious cytokines, indicating that GTW has suppressive effects on acute inflammatory changes in glomeruli.

Triptolide suppresses CD80 and CD86 expressions and IL-12 production in THP-1 cells

AIM

To investigate the effects of triptolide, a diterpenoid triepoxide from Tripterygium wilfordii Hook F (TWHF), on the co-stimulatory molecule expression and interleukin-12 (IL-12) production from THP-1 cells.

METHODS

THP-1 cells were differentiated into macrophage-like cells by Me2SO, and then cultured with IFN-gamma (500 kU/L) and lipopolysaccharide (LPS) (1 mg/L) with or without triptolide. The surface molecule expressions were analyzed on a FACScan flow cytometer. IL-12p40, IL-12p70 were assayed by ELISA.

RESULTS

Triptolide suppressed CD80 and CD86 expressions on IFN-gamma (500 kU/L) and LPS (1 mg/L) activated THP-1 cells at nontoxic dosages of 2.5-0.625 microg/L. Furthermore, the production of IL-12p40 and IL-12p70 were also significantly reduced in THP-1 cells exposed to triptolide.

CONCLUSION

Triptolide impairs the antigen-presenting function by inhibiting CD80 and CD86 expressions and decreased IL-12p40 and IL-12p70 (bioactive form) productions from the activated THP-1 cells.

In vivo ethanol exposure down-regulates TLR2-, TLR4-, and TLR9-mediated macrophage inflammatory response by limiting p38 and ERK1/2 activation

Ethanol is known to increase susceptibility to infections, in part, by suppressing macrophage function. Through TLRs, macrophages recognize pathogens and initiate inflammatory responses. In this study, we investigated the effect of acute ethanol exposure on murine macrophage activation mediated via TLR2, TLR4, and TLR9. Specifically, the study focused on the proinflammatory cytokines IL-6 and TNF-alpha and activation of p38 and ERK1/2 MAPKs after a single in vivo exposure to physiologically relevant level of ethanol followed by ex vivo stimulation with specific TLR ligands. Acute ethanol treatment inhibited IL-6 and TNF-alpha synthesis and impaired p38 and ERK1/2 activation induced by TLR2, TLR4, and TLR9 ligands. We also addressed the question of whether ethanol treatment modified activities of serine/threonine-specific, tyrosine-specific phosphatases, and MAPK phosphatase type 1. Inhibitors of three families of protein phosphatases did not restore ethanol-impaired proinflammatory cytokine production nor p38 and ERK1/2 activation. However, inhibitors of serine/threonine protein phosphatase type 1 and type 2A significantly increased IL-6 and TNF-alpha levels, and prolonged activation of p38 and ERK1/2 when triggered by TLR4 and TLR9 ligands. In contrast, with TLR2 ligand stimulation, TNF-alpha production was reduced, whereas IL-6 levels, and p38 and ERK1/2 activation were not affected. In conclusion, acute ethanol exposure impaired macrophage responsiveness to multiple TLR agonists by inhibiting IL-6 and TNF-alpha production. Mechanism responsible for ethanol-induced suppression involved inhibition of p38 and ERK1/2 activation. Furthermore, different TLR ligands stimulated IL-6 and TNF-alpha production via signaling pathways, which showed unique characteristics.

Anti-arthritic effect and subacute toxicological evaluation of Baccharis genistelloides aqueous extract

This work studies the potential subacute toxicological effects of the aqueous extract of Baccharis genistelloides (AEBg) and demonstrates a new anti-arthritic therapeutic effect. The treatment of the collagen-induced arthritis (CIA) group with 4.2 mg/kg AEBg induced an important decrease (75%) in CIA severity in all animals, while the 42 mg/kg dose treated only 50% of animals. After AEBg treatment, no significant differences were observed in body weight, aspect, color and relative weight of liver, kidneys, thymus or lungs between CIA groups. CIA and healthy AEBg groups treated with both doses did not show genotoxic effects to liver and kidney cells by the Comet assay, compared to its own control group. The augmented AST in the CIA group, compared to healthy control one was regularized by the AEBg treatment with 4.2 mg/kg but not with 42 mg/kg. No other significant difference was found on serum biochemical parameters, as well as on spontaneous or stimulated lymphocyte proliferation between CIA groups. The treatment of healthy animals with AEBg 4.2 mg/kg did not change the aspect, color or relative weight of kidneys, liver or lungs but reduced the body weight, the thymus and popliteal lymph node (PLN) relative weight and serum glucose and triglyceride levels. Concluding, our results indicate an anti-arthritic effects of AEBg without liver and kidney subacute toxicity and hypoglycemic and hypotriglyceridemic actions on healthy animals.

Green tea polyphenol epigallocatechin-3-gallate (EGCG) differentially inhibits interleukin-1 beta-induced expression of matrix metalloproteinase-1 and -13 in human chondrocytes

Interleukin-1beta (IL-1beta)-induced inflammatory response in arthritic joints include the enhanced expression and activity of matrix metalloproteinases (MMPs), and their matrix degrading activity contribute to the irreversible loss of cartilage and may also be associated with sustained chronic inflammation. We have earlier shown that green tea (Camellia sinensis) polyphenol epigallocatechin-3-gallate (EGCG) was non-toxic to human chondrocytes [Singh R, Ahmed S, Islam N, Goldberg VM, and Haqqi TM (2002) Arthritis Rheum 46: 2079-2086] and inhibits the expression of inflammatory mediators in arthritic joints [Haqqi TM, Anthony DD, Gupta S, Ahmed N, Lee MS, Kumar GK, and Mukhtar H (1999) Proc Natl Acad Sci USA 96: 4524-4529]. Here we show that EGCG at micromolar concentrations was highly effective in inhibiting the IL-1beta-induced glycosaminoglycan (GAG) release from human cartilage explants in vitro. EGCG also inhibited the IL-1beta-induced mRNA and protein expression of MMP-1 and MMP-13 in human chondrocytes. Importantly, EGCG showed a differential, dose-dependent inhibitory effect on the expression and activity of MMP-13 and MMP-1. A similar differential dose-dependent inhibition of transcription factors NF-kappaB and AP-1 by EGCG was also noted. These results for the first time demonstrate a differential dose-dependent effect of EGCG on the expression and activity of MMPs and on the activities of transcription factors NF-kappaB and AP-1 and provide insights into the molecular basis of the reported anti-inflammatory effects of EGCG. These results also suggest that EGCG or compounds derived from it may be therapeutically effective inhibitors of IL-1beta-induced production of matrix-degrading enzymes in arthritis.