Tripterygium Wilfordii Hook F Extract Research Articles

Extinguish the Fire: Anti-inflammatory Strategies for Over Immune Activation in Chronic HIV-1 Infection

Extinguish the Fire: Anti-inflammatory Strategies for Over Immune Activation in Chronic HIV-1 Infection

Cardiac toxicity of Triptergium wilfordii Hook F. may correlate with its inhibition to hERG channel

Tripterygium wilfordii Hook F. (TWHF) is a Chinese traditional medicine with cardiac toxicities. However, the mechanism of acute cardiac toxicity is not very clear. By using patch clamp techniques, we found that 0.05 mg/ml and 0.1 mg/ml of the aqueous crude extract of TWHF inhibit 21.4 ± 1.6% and 86.7 ± 5.7% (n = 5) of hERG current Amplitudes (IhERG) respectively. We further found that Celastrol, one of main components of TWHF, inhibits hERG with an IC50 of 0.83 μM. Additional mutagenesis studies show that mutations of T623A, S624A and F656A significantly alter the inhibition and S624A has the strongest effect, supported by our docking model. Our data suggest that inhibition of hERG channel activity by Celastrol contributed to TWHF cardiotoxicity.

Plasma metabolic profiling analysis of Strychnos nux-vomica Linn. and Tripterygium wilfordii Hook F-induced renal toxicity using metabolomics coupled with UPLC/Q-TOF-MS.

Both Strychnos nux-vomica Linn. (SNV) and Tripterygium wilfordii Hook F (TwHF) have received extensive attention due to their excellent clinical efficacies. However, clinical applications of SNV and TwHF have been limited by their narrow therapeutic windows and severe kidney toxicities. In this paper, based on ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS), endogenous metabolites after administration of SNV and TwHF extracts were detected, and biomarkers were screened successfully. Additionally, the levels of Cr and BUN in serum and pathological findings of kidneys were detected and observed. Finally, both biochemical and pathological tests of the SNV group and TwHF group indicated that kidney damage had occurred. After comparison with the normal saline group, 15 nephrotoxic biomarkers were selected from the SNV group, and 17 nephrotoxic biomarkers were selected from the TwHF group. The experimental results showed that there are some differences in the mechanisms of nephrotoxicity induced by SNV and TwHF, which are significant for revealing the mechanisms of renal injury of different medicines.

The Pharmacological Effects and Mechanism of Tripterygium wilfordii Hook F in Central Nervous System Autoimmunity.

Extracts of the Chinese herb Tripterygium wilfordii Hook F (TwHF) have potent anti-inflammatory functions and are widely used to treat rheumatoid arthritis and Crohn's disease. They have also been considered as potential drugs in the treatment of multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis. A systematic search of MEDLINE, EMBASE, PubMed, and the China National Knowledge Infrastructure (CNKI) was performed. We reviewed many Chinese- and English-language articles. Recent studies have indicated that TwHF extracts, such as triptolide and tripchlorolide, are able to attenuate progression of this neuroimmunologic disorder because of their immunoregulatory, neurotrophic, and neuroprotective effects, but use of these extracts is often accompanied by acute and chronic toxicity. This review systematically summarizes the effects, safety consideration, and molecular mechanisms of action of TwHF extracts with regard to their inhibition of microglia activation, T cell functions, and transcriptional activation of nuclear factor (NF)-κB signaling.

Tripterygium wilfordii Hook F extract in cART-treated HIV patients with poor immune response: a pilot study to assess its immunomodulatory effects and safety

Background:Despite combination antiretroviral therapy (cART), 20% of HIV-infected patients are unable to achieve adequate immunologic recovery, in which immune activation plays a crucial role. We hypothesize that extract of Tripterygium wilfordii Hook F (TwHF), a Chinese medication used to treat autoimmune diseases, has immunomodulatory effects that may help CD4 cell recovery.Methods:Eighteen cART-treated HIV-infected patients virally suppressed for over 12 months with suboptimal CD4 cell recovery were enrolled. TwHF extract was administered at a dosage of 10 mg three times daily for 12 months. T-cell subsets and activation markers were evaluated at baseline and during follow-up. The trial was registered at Clinicaltrials.gov (NCT02002286).Results:TwHF extract was associated with a mean increase in CD4 cell count of 88 cells/μl (95% confidential interval [CI], 72–105 cells/μl) after one year of treatment. A significant increase in the mean rate of CD4 cell recovery (26 before vs 75 cells/μl/year after TwHF use, P < 0.001) was observed. Analysis of 13 patients with activation profiles suggested that TwHF extract was associated with a decrease in T-cell immune activation which was temporally correlated with CD4 cell recovery. No discontinuation of TwHF extract was reported.Conclusion:Use of TwHF extract in HIV-infected patients was associated with a reduction in T-cell activation and improved CD4 recovery with an excellent safety profile.

Treatment of diabetic nephropathy with Tripterygium wilfordii Hook F extract: a prospective, randomized, controlled clinical trial

BackgroundDiabetic nephropathy (DN) is the most common cause of end-stage renal failure. Although angiotensin II receptor blockers (ARBs) can be used to attenuate proteinuria in DN patients, their efficacy remains limited. This clinical trial aimed to evaluate the efficacy of Tripterygium wilfordii Hook F (TwHF) extract in the treatment of type 2 diabetes mellitus (DM)-induced nephropathy.MethodsA total of 65 DN patients with proteinuria levels ≥ 2.5 g/24 h and serum creatinine levels < 3 mg/dl were enrolled in this six-month, prospective, randomized, controlled study. The patients were randomized into treatment groups that received either 120 mg of TwHF extract per day for three months, followed by 60 mg per day for three more months, or 160 mg of valsartan daily for six months. The urinary protein and estimated glomerular filtration (eGFR) level were measured at one, three, and six months after the commencement of treatment. The primary measure of treatment efficacy was a reduction in the 24-h urine protein level between baseline and the end of the study, and the secondary measure of treatment efficacy was a reduction in the eGFR value.ResultsAt the end of the treatment period, the mean urine protein level in the TwHF group was dramatically decreased (4.99 ± 2.25 g/24 h vs 2.99 ± 1.81 g/24 h, p < 0.01), with decreases at one, three, and six months of 32.9%, 38.8%, and 34.3%, respectively. In contrast, the proteinuria in the valsartan group was not significantly attenuated, and the decreases in urine protein levels at treatment months one, three, and six were 1.05%, 10.1%, and -11.7%, respectively. The mean decrease in eGFR in the valsartan group was greater than that in the TwHF group (26.4% vs. 13.7%, respectively; p =0.067).ConclusionsTwHF extract can reduce the urine protein level of DN patients and represents a novel, potentially effective, and safe drug for the treatment of DN patients with proteinuria.Trial registrationClinicalTrials.gov: NCT00518362

Extracts ofTripterygium wilfordiiHook F in the Treatment of Rheumatoid Arthritis: A Systemic Review and Meta-Analysis of Randomised Controlled Trials

Clinical trials have reported the effects of Tripterygium wilfordii Hook F (TwHF) extracts (TEs) in the treatment of rheumatoid arthritis (RA); however, the results have been inconsistent. This meta-analysis is aimed to assess the safety of TEs and their effects on the treatment of RA. Randomised controlled trials (RCTs) comparing the effects of TEs and placebo (PBO) or disease-modifying antirheumatic drugs (DMARDs) in patients with RA were included. Weighted mean differences (MDs) were calculated for net changes by employing fixed-effect or random-effects models. After filtering, ten RCTs (involving 733 participants) were included in this study. The methodological quality of these studies was generally low. Compared with DMARDs, TEs alone produced a mild increase in grip strength (GS) (P = 0.02; standard mean difference (SMD) = 0.81; 95% confidence interval (CI): 0.14 to 1.48). The most common adverse effects (AEs) of TEs were gastrointestinal discomfort, menstruation disorders, and amenorrhea. In conclusion, TEs, as a sort of “herbal DMARD,” could be as effective as synthetic DMARDs in the treatment of RA. However, the efficacy of TEs in treating RA should be further estimated with better designed, fully powered, confirmatory RCTs that apply the American College of Rheumatology (ACR) improvement criteria to evaluate their outcomes.

Triptolide in the treatment of psoriasis and other immune‐mediated inflammatory diseases

Apart from cancer chronic (auto)immune-mediated diseases are a major threat for patients and a challenge for physicians. These conditions include classic autoimmune diseases like systemic lupus erythematosus, systemic sclerosis and dermatomyositis and also immune-mediated inflammatory diseases such as rheumatoid arthritis and psoriasis. Traditional therapies for these conditions include unspecific immunosuppressants including steroids and cyclophosphamide, more specific compounds such as ciclosporin or other drugs which are thought to act as immunomodulators (fumarates and intravenous immunoglobulins). With increasing knowledge about the underlying pathomechanisms of the diseases, targeted biologic therapies mainly consisting of anti-cytokine or anti-cytokine receptor agents have been developed. The latter have led to a substantial improvement of the induction of long term remission but drug costs are high and are not affordable in all countries. In China an extract of the herb Tripterygium wilfordii Hook F. (TwHF) is frequently used to treat autoimmune and/or inflammatory diseases due to its favourable cost-benefit ratio. Triptolide has turned out to be the active substance of TwHF extracts and has been shown to exert potent anti-inflammatory and immunosuppressive effects in vitro and in vivo. There is increasing evidence for an immunomodulatory and partly immunosuppressive mechanism of action of triptolide. Thus, compounds such as triptolide or triptolide derivatives may have the potential to be developed as a new class of drugs for these diseases. In this review we summarize the published knowledge regarding clinical use, pharmacokinetics and the possible mode of action of triptolide in the treatment of inflammatory diseases with a particular focus on psoriasis.

A Chinese herb Tripterygium wilfordii Hook F in the treatment of rheumatoid arthritis: mechanism, efficacy, and safety

Tripterygium wilfordii Hook F (TwHF) is a Chinese herb with immunosuppressive effects and an established history of use in the treatment of rheumatoid arthritis (RA). Numerous preclinical studies have demonstrated that the extracts from the root of TwHF inhibit the expression of proinflammatory cytokines, proinflammatory mediators, adhesion molecules, and matrix metalloproteinases by macrophages, lymphocytes, synovial fibroblasts, and chondrocytes. TwHF also induces apoptosis in lymphocytes and synovial fibroblasts and inhibits their proliferation. Except numerous uncontrolled clinical trials, there are some prospective, double-blind, randomized, and placebo/sulfasalazine-controlled trials, also demonstrating greater improvement in RA disease activity by TwHF extract than placebo/sulfasalazine. Radiographic progression in RA may also be retarded by TwHF. Therefore, the immunosuppressive, cartilage protective, and anti-inflammatory effects of TwHF extracts are well demonstrated, and TwHF extract is an alternative disease modifying anti-rheumatic drug (DMARD) for the patients with RA refractory to conventional therapy.

Comparison ofTripterygium wilfordiiHook F Versus Sulfasalazine in the Treatment of Rheumatoid Arthritis

Extracts of the medicinal plant Tripterygium wilfordii Hook F (TwHF) have been used in China for centuries to treat a spectrum of inflammatory diseases. To compare the benefits and side effects of TwHF extract with those of sulfasalazine for the treatment of active rheumatoid arthritis. Randomized, controlled trial. A computer-generated code with random, permuted blocks was used to assign treatment. 2 U.S. academic centers (National Institutes of Health, Bethesda, Maryland, and University of Texas, Dallas, Texas) and 9 rheumatology subspecialty clinics (in Dallas and Austin, Texas; Tampa and Fort Lauderdale, Florida; Arlington, Virginia; Duncanville, Pennsylvania; Wheaton and Greenbelt, Maryland; and Lansing, Michigan). 121 patients with active rheumatoid arthritis and 6 or more painful and swollen joints. TwHF extract, 60 mg 3 times daily, or sulfasalazine, 1 g twice daily. Patients could continue stable doses of oral prednisone or nonsteroidal anti-inflammatory drugs but had to stop taking disease-modifying antirheumatic drugs at least 28 days before randomization. The primary outcome was the rate of achievement of 20% improvement in the American College of Rheumatology criteria (ACR 20) at 24 weeks. Secondary end points were safety; radiographic scores of joint damage; and serum levels of interleukin-6, cholesterol, cortisol, and adrenocorticotropic hormone. Outcome data were available for only 62 patients at 24 weeks. In a mixed-model analysis that imputed data for patients who dropped out, 65.0% (95% CI, 51.6% to 76.9%) of the TwHF group and 32.8% (CI, 21.3% to 46.0%) of the sulfasalazine group met the ACR 20 response criteria (P=0.001). Patients receiving TwHF also had significantly higher response rates for ACR 50 and ACR 70 in mixed-model analyses. Analyses of only completers showed similar significant differences between the treatment groups. Significant improvement was demonstrated in all individual components of the ACR response, including the Health Assessment Questionnaire disability score. Interleukin-6 levels rapidly and significantly decreased in the TwHF group. Although not statistically significant, radiographic progression was lower in the TwHF group. The frequency of adverse events was similar in both groups. Only 62% and 41% of patients continued receiving TwHF extract and sulfasalazine, respectively, during the 24 weeks of the study. Long-term outcome data were not collected on participants who discontinued treatment. In patients who continued treatment for 24 weeks and could also use stable oral prednisone and nonsteroidal anti-inflammatory drugs, attainment of the ACR 20 response criteria was significantly greater with TwHF extract than with sulfasalazine.

Therapeutic Impact of the Ethyl Acetate Extract of Tripterygium wilfordii Hook F on Nephritis in NZB/W F1 Mice

This study was designed to examine the potential usage of the ethyl acetate (EA) extract of Tripterygium wilfordii Hook F (TwHF), a Chinese herbal medicine, in the treatment of systemic lupus erythematosus. A total of 48 twenty-eight-week old female NZB/W F1 mice were randomly divided into three groups and orally administered vehicle, the EA extract of TwHF at 18.25 mg/kg (EAlow) or 36.5mg/kg (EAhigh), respectively, for 14 weeks. Proteinuria and serum anti-ds-DNA antibody titers were assayed before and after treatment. At the end of treatment, all animals were sacrificed and pathologic and Immunohistologic changes in the kidneys and spleens were examined by observers blinded to the treatment regimens. At 28 weeks of age, proteinuria (> 30mg/dL) and anti-ds-DNA antibody were found in all mice of the 3 groups without significant difference. At the end of treatment, the mean proteinuria of the EAlow and EAhigh groups was significantly less than that of the vehicle group. Histological evidence of glomerulonephritis, glomerular deposition of IgG and complement 3 and cellular infiltration in the interstitium and perivascular regions were significantly less severe in the EA extract-treated mice than in vehicle-treated mice. Treatment with the EA extract significantly inhibited the progression of kidney disease in NZB/W F1 mice, though had no significant effect on the levels of anti-dsDNA antibody.

Therapeutic impact of the ethyl acetate extract of Tripterygium wilfordii Hook F on nephritis in NZB/W F1 mice

This study was designed to examine the potential use of the ethyl acetate (EA) extract of Tripterygium wilfordii Hook F (TwHF), a Chinese herbal medicine, in the treatment of systemic lupus erythematosus. A total of 48 28-week-old female NZB/W F1 mice were randomly divided into three groups and orally administered vehicle or the EA extract of TwHF at 18.25 mg/kg (EAlow) or 36.5 mg/kg (EAhigh) for 14 weeks. Proteinuria and serum anti-double-stranded (ds)DNA antibody titers were assayed before and after treatment. At the end of treatment, all animals were sacrificed and pathological changes in the kidneys were examined by observers blinded to the treatment regimens. Immunohistological studies were carried out on kidneys and spleens. At 28 weeks of age, proteinuria (>30 mg/dl) and anti-dsDNA antibodies were found in all mice in the three groups. Fourteen, sixteen and fifteen mice in the vehicle, EAlow and EAhigh groups, respectively, completed at least four weeks of treatment. At the end of treatment, the mean proteinuria of the EAlow and EAhigh groups was significantly less than that of the vehicle group and no different from proteinuria at the onset of treatment. Histological evidence of glomerulonephritis, glomerular deposition of IgG and complement 3 and cellular infiltration in the interstitium and perivascular regions were significantly less severe in the EA extract treated mice than in vehicle treated mice. Treatment with the EA extract significantly inhibited the progression of kidney disease in NZB/W F1 mice, though had no significant effect on the levels of anti-dsDNA antibody.

Triptolide suppresses proinflammatory cytokine-induced matrix metalloproteinase and aggrecanase-1 gene expression in chondrocytes

A hallmark of rheumatoid- and osteoarthritis (OA) is proinflammatory cytokine-induced degeneration of cartilage collagen and aggrecan by matrix metalloproteinases (MMPs) and aggrecanases (ADAMTS). Effects of the Chinese herb, Tripterygium wilfordii Hook F (TWHF), on cartilage and its anti-arthritic mechanisms are poorly understood. This study investigated the impact of a purified derivative of TWHF, PG490 (triptolide), on cytokine-stimulated expression of the major cartilage damaging proteases, MMP-3, MMP-13, and ADAMTS4. PG490 inhibited cytokine-induced MMP-3, MMP-13 gene expression in primary human OA chondrocytes, bovine chondrocytes, SW1353 cells, and human synovial fibroblasts. Triptolide was effective at low doses and blocked the induction of MMP-13 by IL-1 in human and bovine cartilage explants. TWHF extract and PG490 also suppressed IL-1-, IL-17-, and TNF-α-induced expression of ADAMTS-4 in bovine chondrocytes. Thus, PG490 could protect cartilage from MMP- and aggrecanase-driven breakdown. The immunosuppressive, cartilage protective, and anti-inflammatory properties could make PG490 potentially a new therapeutic agent for arthritis.

Triptolide, an active component of the Chinese herbal remedy Tripterygium wilfordii Hook F, inhibits production of nitric oxide by decreasing inducible nitric oxide synthase gene transcription.

The ethyl acetate (EA) extract of Tripterygium wilfordii Hook F (TWHF) and its major active component, triptolide, have been reported to be effective in the treatment of rheumatoid arthritis and other autoimmune inflammatory diseases. Nitric oxide (NO) has been recognized as an important mediator of inflammation. This study was therefore undertaken to examine the effects of the EA extract and triptolide on the production of NO and inducible NO synthase (iNOS) gene expression and transcription in vivo and in vitro. Peritoneal macrophages from C57BL/6J mice treated orally with the EA extract of TWHF were assayed for NO production and iNOS messenger RNA (mRNA) expression by reverse transcriptase-polymerase chain reaction. The murine fibroblast cell line NIH3T3 was also assessed for NO production and iNOS mRNA expression, as well as for iNOS promoter activation, Oct-1 nuclear binding capacity, and Oct-1 protein content by transient transfection, electrophoretic mobility shift assay, and immunoblotting, respectively. NO production and iNOS mRNA expression by macrophages from C57BL/6J mice immunized with trinitrophenyl-bovine serum albumin in Freund's complete adjuvant were significantly inhibited by oral administration of the EA extract (52.3% and 59.8% of control, respectively, at one-eighth of the dose that is lethal for 50% of the animals [LD(50)] and 21.0% and 38.1% of control, respectively, at one-fourth the LD(50)). Moreover, the EA extract and triptolide significantly inhibited NO production in vitro in activated peritoneal macrophages, which reflected a decreased level of iNOS mRNA. Finally, triptolide inhibited promoter activity of the iNOS gene and induction of the activity of the regulator of iNOS transcription, Oct-1. The EA extract of TWHF and triptolide inhibit transcription of the iNOS gene. This may contribute to the antiinflammatory effects of this traditional herbal remedy.

Triptolide, an active compound identified in a traditional Chinese herb, induces apoptosis of rheumatoid synovial fibroblasts

BackgroundExtracts of Tripterygium wilfordii Hook F (TWHF), a traditional Chinese herb, have been reported to show efficacy in patients with rheumatoid arthritis (RA). Since RA is not only characterized by inflammation but also by synovial proliferation in the joints, we examined whether triptolide (a constituent of TWHF) could influence the proliferation of rheumatoid synovial fibroblasts (RSF) by induction of apoptosis.ResultsRSF were obtained from RA patients during surgery and were treated with triptolide under various conditions. The viability and proliferation of RSF were measured by the 4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate (WST-1) assay and by 5-bromo-2'-deoxyuridine incorporation, respectively. Apoptosis was identified by detection of DNA fragmentation using an enzyme-linked immunosorbent assay and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL). The role of caspases in apoptosis of RSF was analyzed by measuring caspase-3 activity. Activation of the peroxisome proliferator-activated receptor (PPAR) γ was assessed by a luciferase reporter gene assay using RSF transfected with a plasmid containing the peroxisome proliferator response element. Triptolide decreased viability, inhibited proliferation, and induced apoptosis of RSF in a concentration-dependent manner at very low (nM) concentrations. Caspase-3 activity was increased by treatment with triptolide and was suppressed by caspase inhibitors. Although PPARγ activation was induced by 15-deoxy-Δ12,14-prostaglandin J2, triptolide did not induce it under the same experimental conditions. An extract of TWHF also induced DNA fragmentation in RSF.ConclusionThe mechanism of action remains to be studied; however, triptolide may possibly have a disease-modifying effect in patients with RA.

Triptolide, an active compound identified in a traditional Chinese herb, induces apoptosis of rheumatoid synovial fibroblasts

Extracts of Tripterygium wilfordii Hook F (TWHF), a traditional Chinese herb, have been reported to show efficacy in patients with rheumatoid arthritis (RA). It was also reported that TWHF extracts suppress inflammation in animal models of RA, and inhibit the production of proinflammatory cytokines by several kinds of cells in vitro.

Tripterygium wilfordii Hook F extract suppresses proinflammatory cytokine-induced expression of matrix metalloproteinase genes in articular chondrocytes by inhibiting activating protein-1 and nuclear factor-kappaB activities.

The major pathologic manifestations of rheumatoid arthritis (RA) and osteoarthritis (OA) are joint inflammation and articular cartilage resorption by proinflammatory cytokine-stimulated matrix metalloproteinases (MMPs) and aggrecanases. The Chinese herbal remedy Tripterygium wilfordii Hook F (TWHF) is effective for treatment of various types of arthritis. However, mechanisms and targets of its actions are poorly understood. Anti-inflammatory activities of the extracts of this plant were previously attributed to inhibition of cyclooxygenase-2 mRNA and prostaglandin E(2) synthesis. Here, we show that in primary human femoral head osteoarthritic and normal bovine chondrocytes, TWHF partially or completely inhibited mRNA and protein expression of tumor necrosis factor-alpha, interleukin (IL)-1, and IL-17-inducible MMP-3 and MMP-13. This agent also inhibited cytokine-stimulated MMP-3 protein expression in human synovial fibroblasts. A dose range of 2.5 to 10 ng/ml of TWHF was effectively inhibitory for IL-1. Pretreatment for 30 min or 1 h (but not 2-10 h) after IL-1 treatment with TWHF inhibited MMP-3 RNA induction. The inhibitory doses had no adverse effect on the viability of chondrocytes. Mechanistic studies revealed no impact on the activation of extracellular signal-regulated kinase, p38, and c-Jun N-terminal kinase mitogen-activated protein kinases. Instead, TWHF partially inhibited DNA binding capacity of cytokine-stimulated activating protein-1 (AP-1) and nuclear factor-kappaB (NF-kappaB) transcription factors. Therefore, besides its anti-inflammatory activity, this agent may also be effective in blocking cartilage matrix resorption by MMPs by impairing AP-1 and NF-kappaB binding activities. Thus, TWHF extract contains novel inhibitors of MMP expression that may be of therapeutic potential in arthritis and other conditions associated with increased MMPs.

The molecular mechanism of inhibition of interleukin-1beta-induced cyclooxygenase-2 expression in human synovial cells by Tripterygium wilfordii Hook F extract.

Several extracts of Tripterygium wilfordii Hook F (TWHF) have been reported to be effective in patients with rheumatoid arthritis. We investigated the effect of multi-glycosides ofTWHF (GTW), a TWHF extract, on interleukin (IL)-1beta stimulated human rheumatoid synovial cells. IL-1beta-stimulated synovial cells were used to detect the effects of GTW on cyclooxygenase (COX)-1 and COX-2 activities, expression of COX protein and mRNA, and nuclear transcription factors in experiments using respective reporter plasmids. GTW inhibited prostaglandin E2 production by IL-1beta-stimulated synovial cells in a concentration-dependent manner, and also inhibited COX-2 protein and mRNA expression in a similar fashion to dexamethasone. However, GTW did not act as a glucocorticoid agonist. GTW repressed IL-1beta-induced nuclear factor-kappaB activity, but did not have a significant influence on activating protein-1 activity. The anti-rheumatic effect of GTW or TWHF may be partly mediated through the inhibition of prostaglandin E2 production in human synovial cells due to suppression of COX-2 mRNA, possibly via inhibition of nuclear factor-kappaB activity.

Suppression of carrageenan-induced inflammation in vivo by an extract of the Chinese herbal remedy Tripterygium wilfordii Hook F.

The current studies investigated the effect of subacute administration of an ethyl acetate extract of the Chinese herbal remedy, Tripterygium wilfordii Hook F (TWHF) on the inflammatory response induced by carrageenan in the rat. F344 rats were randomly divided into 3 groups of seven animals. The rats were treated orally for 5 days with either vehicle or an ethyl acetate extract of TWHF at a dose of 270 mg/kg, equivalent to 1/5 of the dose causing death in 50% of the animals. Air pouches were induced subcutaneously on the backs of rats and injected with carrageenan on the last day of treatment. Sixteen hours after carrageenan challenge, the air pouches were removed and analyzed. Student's t-test was employed for statistical analysis. The number of exudate cells and the concentration of PGE2, nitrite and TNF-alpha in the exudate obtained from TWHF-treated animals were significantly reduced (by 69%, 78%, 57% and 77%, respectively) compared to that from vehicle-treated animals. mRNA for cyclooxygenase-2 was markedly suppressed in the air pouch lining tissue of TWHF treated rats (p < 0.001). In contrast, PGE2 content of the kidney and stomach and the production of PGE2, nitrite and TNF-alpha by spleen cells was not affected by treatment with TWHF. These results indicate that TWHF exerts a significant anti-inflammatory activity in vivo.

Effects of tripterygium wilfordii Hook F extracts on induction of cyclooxygenase 2 activity and prostaglandin E2 production

Objective Extracts of the Chinese herbal remedy Tripterygium wilfordii Hook F (TWHF) have been reported to be effective in the treatment of patients with a variety of inflammatory and autoimmune diseases, but the mechanism of this therapeutic effect has not been completely delineated. The present study was designed to assess the effects of TWHF on the in vitro synthesis of prostaglandin E2 (PGE2) and on the expression of the cyclooxygenase isoforms, COX-1 and COX-2, in various human cell types. Methods Monocytes from human peripheral blood (HM), fibroblasts from rheumatoid arthritis synovial tissue (RASF), human neonatal foreskin fibroblasts (HFF), and the histiocytic cell line U937 were cultured for designated time periods with or without lipopolysaccharide (LPS), and in the presence or absence of varying concentrations of the following inhibitors: the methanol/chloroform (T2) extract of TWHF, the ethyl acetate (EA) extract of TWHF, a purified diterpenoid component of TWHF (triptolide), dexamethasone, and indomethacin. Culture supernatants were harvested for PGE2 content assays. Total RNA was extracted from the cells and analyzed for COX-1 and COX-2 messenger RNA (mRNA) expression using reverse transcriptase-polymerase chain reaction or Northern blotting. Results Both the T2 and EA extracts inhibited PGE2 synthesis in the LPS-stimulated HM, RASF, and HFF cells, which was reflected by a marked suppression in the levels of mRNA for COX-2. In contrast, neither extract inhibited PGE2 production in U937 cells that did not express COX-2. Triptolide also inhibited LPS-stimulated induction of COX-2 mRNA and synthesis of PGE2, at the same inhibitory concentration as seen with the EA extract. The effects of T2, EA, and triptolide paralleled the inhibitory action of dexamethasone. Conclusion The data indicate that both the T2 and EA extracts of TWHF, as well as the triptolide component, inhibit PGE2 production in a variety of human cells by blocking the up-regulation of COX-2.