PG490-88, a derivative of triptolide, blocks bleomycin-induced lung fibrosis

Chinese medicine as a therapeutic option for pulmonary fibrosis: Clinical efficacies and underlying mechanisms

ETHNIC PHARMACOLOGICAL RELEVANCE

Pulmonary fibrosis (PF) is a fibrotic interstitial lung disease caused by continuous damage and excessive repair of alveolar epithelial cells, the pathogenesis of which is not fully understood. At present, the incidence of PF has increased significantly around the world. The therapeutic arsenals against PF are relatively limited, with often poor efficacy and many adverse effects. As a conventional and effective therapeutic strategy, traditional Chinese medicine (TCM) has been widely applied in treating lung fibrosis for thousands of years in China. Due to the multi-ingredient, multi-target characteristics, Chinese medicines possess promising clinical benefits for PF treatment.

AIM OF THIS REVIEW

This review aims to systematically analyze the clinical efficacy of Chinese medicine on PF, and further summarize the relevant mechanisms of Chinese medicine treating PF in preclinical studies, in order to provide a comprehensive insight into the beneficial effects of Chinese medicines on PF.

METHODS

Eight major Chinese and English databases were searched from database inception up to October 2022, and all randomized clinical trials (RCTs) investigating the effects of Chinese medicine intervention on effectiveness and safety in the treatment of PF patients were included. Subsequently, preclinical studies related to the treatment of PF in Chinese medicine, including Chinese medicine compounds, Chinese herbal materials and extracts, and Chinese herbal formulas (CHFs) were searched through PubMed and Web of science to summarize the related mechanisms of Chinese medicine against PF.

RESULTS

A total of 56 studies with 4019 patients were included by searching the relevant databases. Total clinical efficacy, pulmonary function, blood gas analysis, lung high resolution CT (HRCT), 6 min walk test (6-MWT), St George's Respiratory Questionnaire (SGRQ) scores, clinical symptom scores, TCM syndrome scores and other outcome indicators related to PF were analyzed. Besides, numerous preclinical studies have shown that many Chinese medicine compounds, Chinese herbal materials and extracts, and CHFs play a preventive and therapeutic role in PF by reducing oxidative stress, ameliorating inflammation, inhibiting epithelial-mesenchymal transition and myofibroblasts activation, and regulating autophagy and apoptosis.

CONCLUSION

Chinese medicines show potential as supplements or substitutes for treating PF. And studies on Chinese medicines will provide a new approach to better management of PF.

Pulmonary fibrosis: Therapeutic and mechanistic insights into the role of phytochemicals

Pulmonary fibrosis (PF) is the devastating consequence of various inflammatory diseases of the lung. PF leads to a reduction of lung function, respiratory failure, and death. Several molecular pathways are involved in PF, such as inflammatory cytokines including tumor necrosis factor α (TNFα), tumor necrosis factor β1 (TNFβ1), interleukin 6 (IL-6), and interleukin 4 (IL-4), reactive oxygen species, matrix metalloproteases, and transforming growth factor-beta (TGF-β). Targeting these processes involved in the progression of PF is essential for the treatment of this disease. Natural products, including plant extracts and active compound that directly target the processes involved in PF, could be suitable therapeutic options with less adverse effects. In the present study, we reviewed the protective effects and the therapeutic role of various bioactive compounds from plants in PF management.

The Study of Cellular Mechanism of Triptolide in the Treatment of Cancer, Bone Loss and Cardiovascular Disease and Triptolide's Toxicity

Triptolide (TPL), the active component of Tripterygium wilfordii Hook F (Twhf) has been used to treat cancer and bone loss conditions for over two hundred years in traditional Chinese medicine (TCM). In this paper, we reviewed the specific molecular mechanisms in the treatment of cancer, bone loss and cardiovascular disease. In addition, we analyze the toxicity of TPL and collect some optimized derivatives extracted from TPL. Although positive results were obtained in most cell culture and animal studies, further studies are needed to substantiate the beneficial effects of TPL.

PG490-88, a derivative of triptolide, suppresses ischemia/reperfusion-induced lung damage by maintaining tight junction barriers and targeting multiple signaling pathways

Previous studies demonstrated that triptolide (PG490) has many anti-inflammatory and immunosuppressive effects. However, little is known about the effect of PG490-88 (a water-soluble derivative of triptolide) on ischemia/reperfusion (I/R)-induced acute lung injury. We assessed the effects of PG490-88 on I/R-induced acute lung injury in rats and on hypoxia/reoxygenation (H/R) in a line of murine epithelial cells. Isolated perfused rat lungs were subjected to 40 min of ischemia, followed by 60 min of reperfusion to induce I/R injury. Induction of I/R led to lung edema, elevated pulmonary arterial pressure, histological evidence of lung inflammation, oxidative stress, and increased levels of TNF-α and CINC-1 in bronchoalveolar lavage fluid. PG490-88 significantly suppressed all of these responses. Additionally, induction of I/R reduced the expression of claudin-4, occludin, and ZO-1, and increased apoptosis in lung tissue. PG490-88 also significantly suppressed these effects. I/R reduced the levels of IκB-α and MKP-1, and increased the levels of nuclear NF-κB and mitogen-activated protein kinase in lung tissue, and PG490-88 suppressed these effects. In vitro studies using mouse lung alveolar epithelial cells indicated that H/R increased the levels of phosphorylated p65 and MIP-2, but decreased the level of IκB-α. PG490-88 also suppressed these effects. In I/R damaged lungs, PG490-88 suppresses the inflammatory response, disruption of tight junction structure, and apoptosis. PG490-88 has the potential as a prophylactic agent to prevent I/R-induced lung injury.

Triptolide inhibits TGF-β-induced matrix contraction and fibronectin production mediated by human Tenon fibroblasts

AIM

To determine if triptolide influences the contractility and fibronectin production in human Tenon fibroblasts (HTFs).

METHODS

HTFs were cultured in type I collagen gels with or without transforming growth factor beta (TGF-β) and/or triptolide. The diameter of the collagen gel was used to measure contraction. Immunoblot analysis was used to quantify myosin light chain (MLC) phosphorylation and integrin expression. Laser confocal fluorescence microscopy was used to monitor the formation of actin stress fibers. Fibronectin production was measured with an enzyme immunoassay.

RESULTS

Triptolide inhibition of contraction in TGF-β-induced collagen gel mediated by HTFs was dose-dependent and statistically significant at 3 nmol/L (P<0.05) and maximal at 30 nmol/L and significantly time dependent at 2d (P<0.05). Triptolide reduced TGF-β-induced expression of integrins α5 and β1, phosphorylation of MLC, and formation of stress fibers in HTFs. Furthermore, the inhibition of triptolide on the attenuated TGF-β-induced production of fibronectin by HTFs was concentration-dependent and significant at 1 nmol/L (P<0.05) and maximal at 30 nmol/L.

CONCLUSION

Triptolide suppress the contractility of HTFs induced by TGF-β and the production of fibronectin by these cells. It is promising that triptolide treatment may possibly inhibit scar formation after glaucoma filtration surgery.

A Mechanistic Overview of Triptolide and Celastrol, Natural Products from Tripterygium wilfordii Hook F

Triptolide and celastrol are predominantly active natural products isolated from the medicinal plant Tripterygium wilfordii Hook F. These compounds exhibit similar pharmacological activities, including anti-cancer, anti-inflammation, anti-obesity, and anti-diabetic activities. Triptolide and celastrol also provide neuroprotection and prevent cardiovascular and metabolic diseases. However, toxicity restricts the further development of triptolide and celastrol. In this review, we comprehensively review therapeutic targets and mechanisms of action, and translational study of triptolide and celastrol. We systemically discuss the structure-activity-relationship of triptolide, celastrol, and their derivatives. Furthermore, we propose the use of structural derivatives, targeted therapy, and combination treatment as possible solutions to reduce toxicity and increase therapeutic window of these potent natural products from T. wilfordii Hook F.

Triptolide suppresses paraquat induced idiopathic pulmonary fibrosis by inhibiting TGFB1-dependent epithelial mesenchymal transition

Idiopathic pulmonary fibrosis (IPF) and tumor are highly similar to abnormal cell proliferation that damages the body. This malignant cell evolution in a stressful environment closely resembles that of epithelial-mesenchymal transition (EMT). As a popular EMT-inducing factor, TGFβ plays an important role in the progression of multiple diseases. However, the drugs that target TGFB1 are limited. In this study, we found that triptolide (TPL), a Chinese medicine extract, exerts an anti-lung fibrosis effect by inhibiting the EMT of lung epithelial cells. In addition, triptolide directly binds to TGFβ and subsequently increase E-cadherin expression and decrease vimentin expression. In in vivo studies, TPL improves the survival state and inhibits lung fibrosis in mice. In summary, this study revealed the potential therapeutic effect of paraquat induced TPL in lung fibrosis by regulating TGFβ-dependent EMT progression.

Efficacy and Safety of Endoscopic Balloon Dilation for Upper Gastrointestinal Strictures of Crohn's Disease

BACKGROUND

Few articles focused on endoscopic balloon dilation (EBD) in the management of Crohn's strictures in the upper gastrointestinal (GI) tract.

AIMS

The purpose of this study was to evaluate the long-term efficacy and safety of EBD for Crohn's strictures in the upper GI tract and to determine early predictors of response and surgical intervention.

METHODS

All eligible patients who underwent EBD for Crohn's strictures in the upper GI tract were retrospectively reviewed. The long-term success was defined as the recovery of normal diets without surgical intervention over the follow-up period. In order to seek early predictors, patients who achieved long-term success were compared with those who didn't.

RESULTS

A total of 67 dilations of upper GI strictures were performed between June 2011 and March 2015 on 24 patients (mean age 25.6 ± 6.7, 20 male) with Crohn's disease. Technical success was achieved in 62 of 67 dilations (92.5 %) with a complication rate of 3 %. After the median follow-up period of 23.0 months (range 6.2-51.2 months), nine patients underwent surgical intervention, nine patients were still depending on tube feeding; in the meantime, only six (25 %) patients achieved long-term success. Additionally, patients who remained 1 month intervention-free (55.6 vs. 5.9 %, P = 0.015) were more likely to achieve long-term success.

CONCLUSIONS

EBD was a safe procedure, but not a potent therapy for Crohn's upper GI strictures. Meanwhile, 1-month response could serve as an early predictor of the long-term response.

Triptolide mitigates radiation-induced pulmonary fibrosis via inhibition of axis of alveolar macrophages-NOXes-ROS-myofibroblasts

PURPOSE

IR-induced pulmonary fibrosis is one of the most severe late complications of radiotherapy for lung cancer. It is urgently needed to discover a new drug for anti-IR lung fibrosis. Our previous studies have indicated that TPL exhibits both anti-IR lung fibrosis and anti-tumor activities. To reveal the mechanism of TPL on anti-IR lung fibrosis, alveolar macrophages (AMs) were examined for TPL effect on their axis of Nicotinamide adenine dinucleotide phosphate oxidase-reactive oxygen species (NOXes-ROS) and myofibroblast activation.

METHODS AND MATERIALS

The fibrosis-prone C57BL/6 mice were irradiated with 15 Gy on whole chest, then one day later, mice were treated without or with TPL (i.v. 0.25 mg/kg, qod for 1 month). The AMs were collected from bronchoalveolar lavage fluids and studied for the production of ROS and the levels of NOXes. The effect of AMs on myofibroblast activation as labeled with F4/80 or α-SMA (α-smooth muscle actin) were examined using flow cytometry, Western blotting, or immunohistochemical staining.

RESULTS

TPL effectively reduced the IR-induced lung fibrosis as evidenced by the less myofibroblasts, less collagen deposit and less ROS in the IR-lung tissues. We found that ROS which responsible for myofibroblasts activation was mainly from AMs and was NOX2 and NOX4 dependent. TPL significantly reduced the infiltrated AMs in IR-lung tissues, and in addition, down regulated the level of NOX2 and NOX4 in AMs both in vitro and in vivo. Furthermore, by inhibiting NOXes dependent ROS in AMs, TPL deprived AMs' paracrine activation of myofibroblasts.

CONCLUSIONS

Our work demonstrated that the anti-fibrotic effect of TPL on IR-induced pulmonary fibrosis was related to its inhibition on the axis of alveolar macrophages-NOXes-ROS-myofibroblasts.

Development and assessment of countermeasure formulations for treatment of lung injury induced by chlorine inhalation

Chlorine is a commonly used, reactive compound to which humans can be exposed via accidental or intentional release resulting in acute lung injury. Formulations of rolipram (a phosphodiesterase inhibitor), triptolide (a natural plant product with anti-inflammatory properties), and budesonide (a corticosteroid), either neat or in conjunction with poly(lactic:glycolic acid) (PLGA), were developed for treatment of chlorine-induced acute lung injury by intramuscular injection. Formulations were produced by spray-drying, which generated generally spherical microparticles that were suitable for intramuscular injection. Multiple parameters were varied to produce formulations with a wide range of in vitro release kinetics. Testing of selected formulations in chlorine-exposed mice demonstrated efficacy against key aspects of acute lung injury. The results show the feasibility of developing microencapsulated formulations that could be used to treat chlorine-induced acute lung injury by intramuscular injection, which represents a preferred route of administration in a mass casualty situation.

Non-invasive Imaging of Idiopathic Pulmonary Fibrosis Using Cathepsin Protease Probes

Idiopathic pulmonary fibrosis (IPF) is a lethal, chronic, progressive disease characterized by formation of scar tissue within the lungs. Because it is a disease of unknown etiology, it is difficult to diagnose, to predict disease course and to devise treatment strategies. Recent evidence suggests that activated macrophages play key roles in the pathology of IPF. Therefore, imaging probes that specifically recognize these pools of activated immune cells could provide valuable information about how these cells contribute to the pathobiology of the disease. Here we demonstrate that cysteine cathepsin-targeted imaging probes can be used to monitor the contribution of macrophages to fibrotic disease progression in the bleomycin-induced murine model of pulmonary fibrosis. Furthermore, we show that the probes highlight regions of macrophage involvement in fibrosis in human biopsy tissues from IPF patients. Finally, we present first-in-human results demonstrating non-invasive imaging of active cathepsins in fibrotic lesions of patients with IPF. Together, our findings validate small molecule cysteine cathepsin probes for clinical PET imaging and suggest that they have the potential to be used to generate mechanistically-informative molecular information regarding cellular drivers of IPF disease severity and progression.

Immunosuppressive, anti-inflammatory and anti-cancer properties of triptolide: A mini review

OBJECTIVE

Triptolide, the active component of Tripterygium wilfordii Hook F has been used to treat autoimmune and inflammatory conditions for over two hundred years in traditional Chinese medicine. However, the processes through which triptolide exerts immunosuppression and anti-inflammation are not understood well. In this review, we discuss the autoimmune disorders and inflammatory conditions that are currently treated with triptolide. Triptolide also possesses anti-tumorigenic effects. We discuss the toxicity of various triptolide derivatives and offer suggestions to improve its safety. This study also examines the clinical trials that have investigated the efficacy of triptolide. Our aim is to examine the mechanisms that are responsible for the immunosuppressive, anti-inflammatory, and anti-cancer effects of triptolide.

MATERIALS AND METHODS

The present review provides a comprehensive summary of the literature with respect to the immunosuppressive, anti-inflammatory, and anti-cancer properties of triptolide.

RESULTS

Triptolide possesses immunosuppressive, anti-inflammatory, and anti-cancer effects.

CONCLUSION

Triptolide can be used alone or in combination with existing therapeutic modalities as novel treatments for autoimmune disorders, cancers, and for immunosuppression.

Triptolide Mitigates Radiation-Induced Pulmonary Fibrosis

Triptolide (TPL) may mitigate radiation-induced late pulmonary side effects through its inhibition of global pro-inflammatory cytokines. In this study, we evaluated the effect of TPL in C57BL/6 mice, the animals were exposed to radiation with vehicle (15 Gy), radiation with TPL (0.25 mg/kg i.v., twice weekly for 1, 2 and 3 months), radiation and celecoxib (CLX) (30 mg/kg) and sham irradiation. Cultured supernatant of irradiated RAW 264.7 and MLE-15 cells and lung lysate in different groups were enzyme-linked immunosorbent assays at 33 h. Respiratory rate, pulmonary compliance and pulmonary density were measured at 5 months in all groups. The groups exposed to radiation with vehicle and radiation with TPL exhibited significant differences in respiratory rate and pulmonary compliance (480 ± 75/min vs. 378 ± 76/min; 0.6 ± 0.1 ml/cm H2O/p kg vs. 0.9 ± 0.2 ml/cm H2O/p kg). Seventeen cytokines were significantly reduced in the lung lysate of the radiation exposure with TPL group at 5 months compared to that of the radiation with vehicle group, including profibrotic cytokines implicated in pulmonary fibrosis, such as IL-1β, TGF- β1 and IL-13. The radiation exposure with TPL mice exhibited a 41% reduction of pulmonary density and a 25% reduction of hydroxyproline in the lung, compared to that of radiation with vehicle mice. The trichrome-stained area of fibrotic foci and pathological scaling in sections of the mice treated with radiation and TPL mice were significantly less than those of the radiation with vehicle-treated group. In addition, the radiation with TPL-treated mice exhibited a trend of improved survival rate compared to that of the radiation with vehicle-treated mice at 5 months (83% vs. 53%). Three radiation-induced profibrotic cytokines in the radiation with vehicle-treated group were significantly reduced by TPL treatment, and this partly contributed to the trend of improved survival rate and pulmonary density and function and the decreased severity of pulmonary fibrosis at 5 months. Our findings indicate that TPL could be a potential new agent to mitigate radiation-induced pulmonary fibrosis.

Triptolide ameliorates colonic fibrosis in an experimental rat model

Triptolide is known to exert anti-inflammatory and immunomodulatory activities; however, its impact on intestinal fibrosis has not been previously examined. Based on our previous studies of the suppressive activity of triptolide on human colonic subepithelial myofibroblasts and the therapeutic efficacy of triptolide in Crohn's disease, it was hypothesized that triptolide may have beneficial effects on intestinal fibrosis. In the present study, colonic fibrosis was induced in rats by 6 weekly repeated administration with a low-dose of 2,4,6-trinitrobenzene sulfonic acid (TNBS) and was then treated with triptolide or PBS daily (control) simultaneously. Extracellular matrix (ECM) deposition in the colon was examined with image analysis of Masson Trichrome staining. Total collagen levels in colonic homogenates were measured by a Sircol assay. Collagen Iα1 transcripts and collagen I protein were measured ex vivo in the isolated colonic subepithelial myofibroblasts by reverse transcription-quantitative polymerase chain reaction and immunoblot analysis, respectively. The results indicated that triptolide decreased ECM deposition and collagen production in the colon, and inhibited collagen Iα1 transcripts and collagen I protein expression in the isolated subepithelial myofibroblasts of the rats with colonic fibrosis. In conclusion, triptolide ameliorates colonic fibrosis in the experimental rat model, suggesting triptolide may be a promising compound for inflammatory bowel disease treatment.

Triptolide inhibits TGF-β1-induced cell proliferation in rat airway smooth muscle cells by suppressing Smad signaling

BACKGROUND

We have reported that triptolide can inhibit airway remodeling in a murine model of asthma via TGF-β1/Smad signaling. In the present study, we aimed to investigate the effect of triptolide on airway smooth muscle cells (ASMCs) proliferation and the possible mechanism.

METHODS

Rat airway smooth muscle cells were cultured and made synchronized, then pretreated with different concentration of triptolide before stimulated by TGF-β1. Cell proliferation was evaluated by MTT assay. Flow cytometry was used to study the influence of triptolide on cell cycle and apoptosis. Signal proteins (Smad2, Smad3 and Smad7) were detected by western blotting analysis.

RESULTS

Triptolide significantly inhibited TGF-β1-induced ASMC proliferation (P<0.05). The cell cycle was blocked at G1/S-interphase by triptolide dose dependently. No pro-apoptotic effects were detected under the concentration of triptolide we used. Western blotting analysis showed TGF-β1 induced Smad2 and Smad3 phosphorylation was inhibited by triptolide pretreatment, and the level of Smad7 was increased by triptolide pretreatment.

CONCLUSIONS

Triptolide may function as an inhibitor of asthma airway remodeling by suppressing ASMCs proliferation via negative regulation of Smad signaling pathway.

Triptolide inhibits TGF-β1 induced proliferation and migration of rat airway smooth muscle cells by suppressing NF-κB but not ERK1/2

BACKGROUND

Airway remodeling contributes to increased mortality in asthma. We have reported that triptolide can inhibit airway remodeling in a mouse asthma model. In this study, we aimed to investigate the effect of triptolide on airway smooth muscle cells (ASMCs) proliferation, migration and the possible mechanism.

METHODS

Rat airway smooth muscle cells were cultured and made synchronized, then pretreated with different concentrations of triptolide before stimulated by TGF-β1. Cell proliferation was evaluated by cell counting and MTT assay. Flow cytometry was used to study the influence of triptolide on cell cycle. Migration was measured by Transwell analysis. Signal proteins (NF-κB p65 and ERK1/2) were detected by western blotting analysis. LDH releasing test and flow cytometry analysis of apoptosis were also performed to explore the potential cytotoxic or pro-apoptotic effects of triptolide.

RESULTS

Triptolide significantly inhibited TGF-β1 induced ASMC proliferation and migration (p<0.05). The cell cycle was blocked at G1/S-interphase by triptolide dose dependently. Western blotting analysis showed TGF-β1 induced NF-κB p65 phosphorylation was inhibited by triptolide pretreatment, but ERK1/2 was not affected. No cytotoxic or pro-apoptotic effects were detected under the concentration of triptolide we used.

CONCLUSIONS

Triptolide may function as an inhibitor of asthma airway remodeling by suppressing ASMCs proliferation and migration through inactivation of NF-κB pathway. This article is protected by copyright. All rights reserved.

A critical role for the mTORC2 pathway in lung fibrosis

A characteristic of dysregulated wound healing in IPF is fibroblastic-mediated damage to lung epithelial cells within fibroblastic foci. In these foci, TGF-β and other growth factors activate fibroblasts that secrete growth factors and matrix regulatory proteins, which activate a fibrotic cascade. Our studies and those of others have revealed that Akt is activated in IPF fibroblasts and it mediates the activation by TGF-β of pro-fibrotic pathways. Recent studies show that mTORC2, a component of the mTOR pathway, mediates the activation of Akt. In this study we set out to determine if blocking mTORC2 with MLN0128, an active site dual mTOR inhibitor, which blocks both mTORC1 and mTORC2, inhibits lung fibrosis. We examined the effect of MLN0128 on TGF-β-mediated induction of stromal proteins in IPF lung fibroblasts; also, we looked at its effect on TGF-β-mediated epithelial injury using a Transwell co-culture system. Additionally, we assessed MLN0128 in the murine bleomycin lung model. We found that TGF-β induces the Rictor component of mTORC2 in IPF lung fibroblasts, which led to Akt activation, and that MLN0128 exhibited potent anti-fibrotic activity in vitro and in vivo. Also, we observed that Rictor induction is Akt-mediated. MLN0128 displays multiple anti-fibrotic and lung epithelial-protective activities; it (1) inhibited the expression of pro-fibrotic matrix-regulatory proteins in TGF-β-stimulated IPF fibroblasts; (2) inhibited fibrosis in a murine bleomycin lung model; and (3) protected lung epithelial cells from injury caused by TGF-β-stimulated IPF fibroblasts. Our findings support a role for mTORC2 in the pathogenesis of lung fibrosis and for the potential of active site mTOR inhibitors in the treatment of IPF and other fibrotic lung diseases.

Triptolide: progress on research in pharmacodynamics and toxicology

ETHNOPHARMACOLOGICAL RELEVANCE

Tripterygium wilfordii Hook. f. (Tripterygium wilfordii), also known as Huangteng and gelsemium elegan, is a traditional Chinese medicine that has been marketed in China as Tripterygium wilfordii glycoside tablets. Triptolide (TP), an active component in Tripterygium wilfordii extracts, has been used to treat various diseases, including lupus, cancer, rheumatoid arthritis and nephritic syndrome. This review summarizes recent developments in the research on the pharmacodynamics, pharmacokinetics, pharmacy and toxicology of TP, with a focus on its novel mechanism of reducing toxicity. This review provides insight for future studies on traditional Chinese medicine, a field that is both historically and currently important.

MATERIALS AND METHODS

We included studies published primarily within the last five years that were available in online academic databases (e.g., PubMed, Google Scholar, CNKI, SciFinder and Web of Science).

RESULTS

TP has a long history of use in China because it displays multiple pharmacological activities, including anti-rheumatism, anti-inflammatory, anti-tumor and neuroprotective properties. It has been widely used for the treatment of various diseases, such as rheumatoid arthritis, nephritic syndrome, lupus, Behcet׳s disease and central nervous system diseases. Recently, numerous breakthroughs have been made in our understanding of the pharmacological efficacy of TP. Although TP has been marketed as a traditional Chinese medicine, its multi-organ toxicity prevents it from being widely used in clinical practice.

CONCLUSIONS

Triptolide, a biologically active natural product extracted from the root of Tripterygium wilfordii, has shown promising pharmacological effects, particularly as an anti-tumor agent. Currently, in anti-cancer research, more effort should be devoted to investigating effective anti-tumor targets and confirming the anti-tumor spectrum and clinical indications of novel anti-tumor pro-drugs. To apply TP appropriately, with high efficacy and low toxicity, the safety and non-toxic dose range for specific target organs and diseases should be determined, the altered pathways and mechanisms of exposure need to be clarified, and an early warning system for toxicity needs to be established. With further in-depth study of the efficacy and toxicity of TP, we believe that TP will become a promising multi-use drug with improved clinical efficacy and safety in the future.

Tumor necrosis factor-α accelerates the resolution of established pulmonary fibrosis in mice by targeting profibrotic lung macrophages

Idiopathic pulmonary fibrosis (IPF) is a relentless, fibrotic parenchymal lung disease in which alternatively programmed macrophages produce profibrotic molecules that promote myofibroblast survival and collagen synthesis. Effective therapies to treat patients with IPF are lacking, and conventional therapy may be harmful. We tested the hypothesis that therapeutic lung delivery of the proinflammatory cytokine tumor necrosis factor (TNF)-α into wild-type fibrotic mice would reduce the profibrotic milieu and accelerate the resolution of established pulmonary fibrosis. Fibrosis was assessed in bleomycin-instilled wild-type and TNF-α(-/-) mice by measuring hydroxyproline levels, static compliance, and Masson's trichrome staining. Macrophage infiltration and programming status was assessed by flow cytometry of enzymatically digested lung and in situ immunostaining. Pulmonary delivery of TNF-α to wild-type mice with established pulmonary fibrosis was found to reduce their fibrotic burden, to improve lung function and architecture, and to reduce the number and programming status of profibrotic alternatively programmed macrophages. In contrast, fibrosis and alternative macrophage programming were prolonged in bleomycin-instilled TNF-α(-/-) mice. To address the role of the reduced numbers of alternatively programmed macrophages in the TNF-α-induced resolution of established pulmonary fibrosis, we conditionally depleted macrophages in MAFIA (MAcrophage Fas-Induced Apoptosis) mice. Conditional macrophage depletion phenocopied the resolution of established pulmonary fibrosis observed after therapeutic TNF-α delivery. Taken together, our results show for the first time that TNF-α is involved in the resolution of established pulmonary fibrosis via a mechanism involving reduced numbers and programming status of profibrotic macrophages. We speculate that pulmonary delivery of TNF-α or augmenting its signaling pathway represent a novel therapeutic strategy to resolve established pulmonary fibrosis.

Triptolide protects rat heart against pressure overload-induced cardiac fibrosis

BACKGROUND

Emerging evidence underlines the role of inflammation activation in the process of cardiac fibrosis. Triptolide has potent anti-inflammatory and anti-proliferative properties, and extensively used in the treatment of chronic inflammatory disorders. In the current study, we test the hypothesis that triptolide treatment facilitates to attenuate chronic pressure overload-induced cardiac fibrosis in a model of rat.

METHODS

Adult male Sprague-Dawley rats were subjected to a suprarenal abdominal aorta constriction (AC) or sham (as control) to induce sustained pressure overload. Eight weeks later, rats were randomly assigned to receive triptolide (9 μg/kg.d, i.p) or vehicle (0.1% dimethyl sulfoxide, 0.2 ml/d, i.p) treatment for an additional 8 weeks.

RESULTS

AC caused significant pathological hypertrophy, cardiac fibrosis and reduced cardiac diastolic function. Triptolide treatment markedly inhibited AC-induced increases in myocardial collagen volume fraction, collagen type I/III deposition, left ventricular end-diastolic pressure, expressions of pro-fibrogenic factors (transforming growth factor-β and angiotensin II) and pro-inflammatory cytokines (IL-1β and IL-6), NF-κB activation and inflammatory cell infiltration in left ventricles compared with vehicle, without affecting cardiac hypertrophy. However, triptolide had no effects on systemic blood pressure and circulating angiotensin II level.

CONCLUSIONS

Collectively, the findings suggested that triptolide treatment elicits favorable anti-fibrogenic effect in a blood pressure-independent manner, at least in part, through inhibiting myocardial pro-fibrogenic factor production and inflammatory activation in the pressure overloaded heart.

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.

Antifibrotic effects of triptolide on hepatic stellate cells and dimethylnitrosamine-intoxicated rats

Triptolide (C₃₈H₄₂O₆N₂, TP, a diterpene triepoxide derived from Tripterygium wilfordii Hook F.), is a potent immunosuppresive and antiinflammatory agent. The present study investigated whether TP exerted antihepatofibrotic effects in vitro and in vivo. A cell line of rat hepatic stellate cells (HSC-T6) was stimulated with tumor necrosis factor-α (TNF-α) or transforming growth factor (TGF)-β1. The inhibitory effects of TP on the nuclear factor-κB (NFκB) signaling cascade and fibrosis markers, including α-smooth muscle actin (α-SMA) and collagen, were assessed. An in vivo therapeutic study was conducted in dimethylnitrosamine (DMN)-treated rats. The rats were randomly assigned to one of three groups: control rats, DMN rats receiving vehicle only and DMN rats receiving TP (20 μg/kg). Treatment was given by gavage twice daily for 3 weeks starting 1 week after the start of DMN administration. TP (5-100 nM) concentration-dependently inhibited the NFκB transcriptional activity induced by TNF-α, lipopolysaccharide and phorbol 12-myristate 13-acetate in HSC-T6 cells. In addition, TP also suppressed TNF-α and TGF-β1-induced collagen deposition and α-SMA secretion in HSC-T6 cells. In vivo, TP treatment significantly reduced hepatic fibrosis scores, collagen contents, IL-6 and TNF-α levels, and the number of α-SMA and NFκB-positive cells in DMN rats. The results showed that TP exerted antifibrotic effects in both HSC-T6 cells and DMN rats.

Immunosuppressant discovery from Tripterygium wilfordii Hook f: the novel triptolide analog (5R)-5-hydroxytriptolide (LLDT-8)

The Chinese traditional herb Tripterygium wilfordii Hook f (TwHF) has been widely used in the treatment of autoimmune and inflammatory diseases. Over the past few decades, great efforts have been made to explore modern preparations of TwHF with higher efficacy, solubility, and lower toxicity. In this study, we reviewed several examples both of naturally occurring compounds and their derivatives in TwHF, and summarized the preclinical evaluations with regard to autoimmune and inflammatory diseases. All of the candidate compounds described herein have been or are currently in clinical trials. Although some studies encountered problems, the data still provided valuable references for future studies. (5R)-5-hydroxytriptolide (LLDT-8, Leitengshu) is a novel triptolide derivative with potent immunosuppressive and anti-inflammatory activities developed at Shanghai Institute of Materia Medica. Indeed, a Phase I clinical trial for this compound has been completed in rheumatoid arthritis patients. The results will provide the basis for the further exploration of this ancient herb and encourage the research and development of valuable traditional Chinese medicine.

Mitogen-activated protein kinase phosphatase-1 modulates regional effects of injurious mechanical ventilation in rodent lungs

RATIONALE

Mechanical ventilation induces heterogeneous lung injury by mitogen-activated protein kinase (MAPK) and nuclear factor-κB. Mechanisms regulating regional injury and protective effects of prone positioning are unclear.

OBJECTIVES

To determine the key regulators of the lung regional protective effects of prone positioning in rodent lungs exposed to injurious ventilation.

METHODS

Adult rats were ventilated with high (18 ml/kg, positive end-expiratory pressure [PEEP] 0) or low Vt (6 ml/kg; PEEP 3 cm H(2)O; 3 h) in supine or prone position. Dorsal-caudal lung mRNA was analyzed by microarray and MAPK phosphatases (MKP)-1 quantitative polymerase chain reaction. MKP-1(-/-) or wild-type mice were ventilated with very high (24 ml/kg; PEEP 0) or low Vt (6-7 ml/kg; PEEP 3 cm H(2)O). The MKP-1 regulator PG490-88 (MRx-108; 0.75 mg/kg) or phosphate-buffered saline was administered preventilation. Injury was assessed by lung mechanics, bronchioalveolar lavage cell counts, protein content, and lung injury scoring. Immunoblotting for MKP-1, and IκBα and cytokine ELISAs were performed on lung lysates.

MEASUREMENTS AND MAIN RESULTS

Prone positioning was protective against injurious ventilation in rats. Expression profiling demonstrated MKP-1 20-fold higher in rats ventilated prone rather than supine and regional reduction in p38 and c-jun N-terminal kinase activation. MKP-1(-/-) mice experienced amplified injury. PG490-88 improved static lung compliance and injury scores, reduced bronchioalveolar lavage cell counts and cytokine levels, and induced MKP-1 and IκBα.

CONCLUSIONS

Injurious ventilation induces MAPK in an MKP-1-dependent fashion. Prone positioning is protective and induces MKP-1. PG490-88 induced MKP-1 and was protective against high Vt in a nuclear factor-κB-dependent manner. MKP-1 is a potential target for modulating regional effects of injurious ventilation.

Triptolide and its expanding multiple pharmacological functions

Triptolide, a diterpene triepoxide, is a major active component of extracts derived from the medicinal plant Tripterygium wilfordii Hook F (TWHF). Triptolide has multiple pharmacological activities including anti-inflammatory, immune modulation, antiproliferative and proapoptotic activity. So, triptolide has been widely used to treat inflammatory diseases, autoimmune diseases, organ transplantation and even tumors. Triptolide cannot only induce tumor cell apoptosis directly, but can also enhance apoptosis induced by cytotoxic agents such as TNF-α, TRAIL and chemotherapeutic agents regardless of p53 phenotype by inhibiting NFκB activation. Recently, the cellular targets of triptolide, such as MKP-1, HSP, 5-Lox, RNA polymerase and histone methyl-transferases had been demonstrated. However, the clinical use of triptolide is often limited by its severe toxicity and water-insolubility. New water-soluble triptolide derivatives have been designed and synthesized, such as PG490-88 or F60008, which have been shown to be safe and potent antitumor agent. Importantly, PG490-88 has been approved entry into Phase I clinical trial for treatment of prostate cancer in USA. This review will focus on these breakthrough findings of triptolide and its implications.

The effects of triptolide on airway remodelling and transforming growth factor-β₁/Smad signalling pathway in ovalbumin-sensitized mice

Airway remodelling contributes to increased morbidity and mortality in asthma. We have reported that triptolide, the major component responsible for the immunosuppressive and anti-inflammatory effects of Tripterygium wilfordii Hook F, inhibited pulmonary inflammation in patients with steroid-resistant asthma. In the present study, we investigated whether triptolide inhibits airway remodelling in a mouse asthma model and observed the effects of triptolide on the transforming growth factor-β₁ (TGF-β₁)/Smad pathway in ovalbumin (OVA)-sensitized mice. BALB/c mice were sensitized to intraperitoneal OVA followed by repetitive OVA challenge for 8 weeks. Treatments included triptolide (40 μg/kg) and dexamethasone (2 mg/kg). The area of bronchial airway (WAt/basement membrane perimeter) and smooth muscle (WAm/basement membrane perimeter), mucus index and collagen area were assessed 24 hr after the final OVA challenge. Levels of TGF-β(1) were assessed by immunohistology and ELISA, levels of TGF-β(1) mRNA were measured by RT-PCR, and levels of pSmad2/3 and Smad7 were assessed by Western blot. Triptolide and dexamethasone significantly reduced allergen-induced increases in the thickness of bronchial airway and smooth muscle, mucous gland hypertrophy, goblet cell hyperplasia and collagen deposition. Levels of lung TGF-β(1) , TGF-β(1) mRNA and pSmad2/3 were significantly reduced in mice treated with triptolide and dexamethasone, and this was associated with a significant increase in levels of Smad7. Triptolide may function as an inhibitor of asthma airway remodelling. It may be a potential drug for the treatment of patients with a severe asthma airway.

Triptolide inhibits extracellular matrix protein synthesis by suppressing the Smad2 but not the MAPK pathway in TGF-beta1-stimulated NRK-49F cells

BACKGROUND

Triptolide has been used for treating various autoimmune diseases. However, it remains unclear whether triptolide exerts effects on extracellular matrix (ECM) synthesis, which plays an important role in renal fibrosis.

METHODS

NRK-49F cells stimulated with TGF-β1 were incubated with triptolide in various concentrations. ECM proteins, including collagen type III and fibronectin, were detected using the reverse transcription real-time PCR and ELISA methods. MAPK and Smad2/3 phosphorylation were measured with western blot. P38 and ERK 1/2 pathways were inhibited with the specific inhibitors, SB203580 and PD98059. The Smad2 signal was blocked with the siRNA method.

RESULTS

Triptolide inhibited ECM synthesis in TGF-β1-stimulated NRK-49F cells in a concentration-dependent manner. Triptolide enhanced TGF-β1-induced activation of the p38, ERK 1/2 signals, whereas it inhibited Smad2 activation. There was no crosstalk between the p38, ERK 1/2 and Smad2 pathways in NRK-49F cells. Inhibition of either the p38 or ERK 1/2 signals reduced ECM synthesis. Triptolide downregulated synthesis of fibronectin and collagen type III in TGF-β1-stimulated cells treated with SB203580 and/or PD98059. SB203580 and/or PD98059 significantly repressed synthesis of fibronectin and collagen type III in TGF-β1-stimulated cells treated with triptolide. Smad2 inhibition by siRNA significantly reduced ECM synthesis. However, ECM synthesis in NRK-49F cells transfected with Smad2 siRNA and treated by triptolide was increased compared with Smad2 siRNA-transfected cells.

CONCLUSION

The effect of triptolide to suppress ECM synthesis by inhibiting Smad2 activation may surpass its stimulating effect on ECM synthesis by activation of p38 and ERK 1/2, leading to a total inhibition of ECM synthesis in TGF-β1-stimulated NRK-49F cells.

Identification of triptolide, a natural diterpenoid compound, as an inhibitor of lung inflammation

Inflammation is associated with various pulmonary diseases and contributes to the pathogenesis of acute lung injury. We previously identified a proinflammatory signaling pathway triggered by G protein-coupled receptors (GPCRs) in which stimulation of G(q)-coupled GPCRs results in activation of the transcription factor NF-kappaB. Because damage to the lung causes the release of multiple mediators acting through G(q)-coupled GPCRs, this signaling pathway is likely to contribute to inflammatory processes in the injured lung. In an effort to identify novel inhibitors of lung inflammation, the National Institutes of Health Clinical Collection, a library of 446 compounds, was screened for inhibitory activity toward production of IL-8 induced by stimulation of the G(q)-coupled tachykinin 1 receptor with substance P in A549 cells. Twenty-eight compounds that significantly inhibited substance P-induced IL-8 production were identified. The most potent inhibitor was triptolide, a diterpenoid compound from Tripterygium wilfordii Hook F, a vine used in traditional Chinese medicine for the treatment of autoimmune diseases. Triptolide inhibited IL-8 production induced by substance P with an IC(50) of 2.3 x 10(-8) M and inhibited NF-kappaB activation in response to an agonist of the protease-activated receptor 2 with an IC(50) of 1.4 x 10(-8) M. Anti-inflammatory effects of triptolide were assessed in vivo using a chlorine gas lung injury model in mice. Triptolide inhibited neutrophilic inflammation and the production of KC (Cxcl1) in the lungs of chlorine-exposed mice. The results demonstrate that triptolide exhibits anti-inflammatory activity in cultured lung cells and in an in vivo model of acute lung injury.

How useful is traditional herbal medicine for pulmonary fibrosis?

IPF, despite considerable advances in clinical management and understanding of its complex pathophysiology, is still a fatal disease without effective treatment. Herbal medicine has been used for more than 5000 years and is the central component of medical practice in many parts of Asia. Not surprisingly, traditional and herbal medicine is also widely applied for treatment of IPF. This review describes the most important herbal medicines that are used for IPF treatment. The relevant experimental studies investigating potential mechanisms of these drugs are discussed. The best conducted clinical studies which have reported beneficial effects of some herbal medications in the management of IPF are also evaluated. Overall, there is considerable experimental support from preclinical studies for some of these herbal medicines, but the translation into clinical practice appears difficult. The clinical trials evaluating their anti-fibrotic potential are not fulfilling the standards expected from 'Western' medicines. Systematic clinical research in this field is still in its infancy, and as such, the routine use of traditional and herbal medicine cannot be recommended for patients suffering from IPF.

A novel CC-chemokine receptor 3 antagonist, Ki19003, inhibits airway eosinophilia and subepithelial/peribronchial fibrosis induced by repeated antigen challenge in mice

CC-chemokine receptor 3 (CCR3) is a chemokine receptor for which major ligands, CC-chemokine ligand (CCL) 11, CCL24, and CCL26, are known to be involved in chemotaxis for eosinophils. In the present study, we evaluated the effect of a low molecular weight CCR3-receptor antagonist, Ki19003 (4-[[5-(2,4-dichlorobenzylureido)pentyl][1-(4-chlorophenyl)ethyl]amino]butanoic acid), on airway remodeling in a mouse model of allergic asthma. BALB/c mice were sensitized twice by intraperitoneal injection of ovalbumin (OA) and exposed daily to 1% OA for 3 weeks. Twenty-four hours after the final antigen challenge, bronchoalveolar lavage and histological examinations were carried out. Ki19003 clearly inhibited antigen-induced increase in the number of eosinophils in bronchoalveolar lavage fluid (BALF), but did not affect the number of other cell types examined in this study. Ki19003 also inhibited the increased production of transforming growth factor-beta1 in BALF and the amount of hydroxyproline in the lungs in a dose-dependent manner. Furthermore, Ki19003 significantly attenuated allergen-induced subepithelial and peribronchial fibrosis. These findings indicate that CCR3 antagonism prevents not only the infiltration of eosinophils into the airways but also the development of allergen-induced subepithelial and peribronchial fibrosis. Therefore, a CCR3 antagonist may be useful in the treatment of airway remodeling, especially subepithelial and peribronchial fibrosis, in allergic asthma.

Neferine, a bisbenzylisoquinline alkaloid attenuates bleomycin-induced pulmonary fibrosis

In this study, we evaluated the potential anti-fibrotic property of neferine, a bisbenzylisoquinline alkaloid extracted from the seed embryo of Nelumbo mucifera Gaertn. Intratracheal bleomycin administration resulted in pulmonary fibrosis 14 and 21 days posttreatment, as evidenced by increased hydroxyproline content in bleomycin group (255.77+/-97.17 microg/lung and 269.74+/-40.92 microg/lung) compared to sham group (170.78+/-76.46 microg/lung and 191.24+/-60.45 microg/lung), and the hydroxyproline was significantly suppressed (193.07+/-39.55 microg/lung and 201.08+/-71.74 microg/lung) by neferine administration (20mg/kg, b.i.d). The attenuated-fibrosis condition was also validated by histological observations. Biochemical measurements revealed that bleomycin caused a significant decrease in lung superoxidae dismutase (SOD) activity, which was accompanied with a significant increase in malondialdehyde (MDA) levels and myeloperoxidase (MPO) activity on the 7th and 14th days. However, neferine reversed the decrease in SOD activity as well as the increase in MDA and MPO activity. Enzyme-linked immunosorbent assay and radio-immunity assay showed that treatment with neferine alleviated bleomycin-induced increase of pro-inflammatory cytokines such as tumor necrosis factor (TNF)-alpha, interleukin (IL)-6 and endothelin-1 in plasma or in tissue. Additionally, neferine blocked bleomycin-induced increases of NF-kappaB in nuclear extracts and TGF-beta(1) in total protein extracts of murine RAW264.7 macrophages. In summary, neferine attenuates bleomycin-induced pulmonary fibrosis in vitro and in vivo. The beneficial effect of neferine might be associated with its activities of anti-inflammation, antioxidation, cytokine and NF-kappaB inhibition.

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.

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 alters mitochondrial functions

Triptolide (TPL), a small molecule purified from the herb Tripterygium wilfordii, has potential clinical application for suppression of chronic autoimmune disorders and inhibition of tumor growth. However, its mechanism of action is largely unknown. In this study, the effect of TPL on mitochondria was explored with a panel of molecular probes that detect the alteration of mitochondrial functions. When Lewis lung carcinoma (LLC) cells were treated with different doses of TPL for four hours, impaired mitochondrial functions were detected. This included an increased production of reactive oxygen species, the opening of the transition pore of mitochondria, the depolarization of the mitochondria membrane, the inhibition of the production of ATP and increased release of ATP as well as the induction of apoptosis. It is likely that by impairment of mitochondrial function, TPL exerts its inhibitory effect on growth of tumor and progression of inflammatory disease.

Glycogen synthase kinase-3beta inhibition attenuates the development of bleomycin-induced lung injury

Glycogen synthase kinase-3 (GSK-3) is an ubiquitous serine-threonine protein kinase that participates in a multitude of cellular processes and has recently been implicated in the pathophysiology of a number of diseases. The aim of this study is to investigate the effects of TDZD-8, a potent and selective GSK-3beta inhibitor, on the development of lung injury caused by administration of bleomycin (BLM). Mice subjected to intra-tracheal administration of BLM developed significant lung injury characterized by marked neutrophil infiltration and tissue edema. An increase in immunoreactivity to nitrotyrosine, iNOS, TNF-alpha and IL-1beta was also observed in the lungs of BLM-treated mice. In contrast, administration of BLM-treated mice with TDZD-8 (1 mg/kg daily) significantly reduced (I) the degree of lung injury, (II) the increase in staining (immunohistochemistry) for myeloperoxidase (MPO), nitrotyrosine, iNOS, TNF-alpha and IL-1beta and (III) the degree of apoptosis, as evaluated by Bax and Bcl-2 immunoreactivity and TUNEL staining. Taken together, these results clearly demonstrate treatment with the GSK-3beta inhibitor TDZD-8 reduces the development of lung injury and inflammation induced by BLM in mice.

The bleomycin animal model: a useful tool to investigate treatment options for idiopathic pulmonary fibrosis?

Different animal models of pulmonary fibrosis have been developed to investigate potential therapies for idiopathic pulmonary fibrosis (IPF). The most common is the bleomycin model in rodents (mouse, rat and hamster). Over the years, numerous agents have been shown to inhibit fibrosis in this model. However, to date none of these compounds are used in the clinical management of IPF and none has shown a comparable antifibrotic effect in humans. We performed a systematic review of publications on drug efficacy studies in the bleomycin model to evaluate the value of this model regarding transferability to clinical use. Between 1980 and 2006 we identified 240 experimental studies describing beneficial antifibrotic compounds in the bleomycin model. 222 of those used a preventive regimen (drug given < or =7 days after last bleomycin application), only 13 were therapeutic trials (>7 days after last bleomycin application). In 5 studies we did not find enough details about the timing of drug application to allow inter-study comparison. It is critical to distinguish between drugs interfering with the inflammatory and early fibrogenic response from those preventing progression of fibrosis, the latter likely much more meaningful for clinical application. All potential antifibrotic compounds should be evaluated in the phase of established fibrosis rather than in the early period of bleomycin-induced inflammation for assessment of its antifibrotic properties. Further care should be taken in extrapolation of drugs successfully tested in the bleomycin model due to partial reversibility of bleomycin-induced fibrosis over time. The use of alternative and more robust animal models, which better reflect human IPF, is warranted.

Enhanced Antitumor Effect of Combined Triptolide and Ionizing Radiation

PURPOSE

The lack of effective treatment for pancreatic cancer results in a very low survival rate. This study explores the enhancement of the therapeutic effect on human pancreatic cancer via the combination of triptolide and ionizing radiation (IR).

EXPERIMENTAL DESIGN

In vitro AsPC-1 human pancreatic cancer cells were treated with triptolide alone, IR alone, or triptolide plus IR. Cell proliferation was analyzed with sulforhodamine B (SRB) method and clonogenic survival; comparison of apoptosis induced by the above treatment was analyzed by annexin V-propidium iodide (PI) staining. Furthermore, the expression of apoptotic pathway intermediates was measured by the assay of caspase activity and Western blot. Mitochondrial transmembrane potential was determined by JC-1 assay. In vivo, AsPC-1 xenografts were treated with 0.25 mg/kg triptolide, 10 Gy IR, or triptolide plus IR. The tumors were measured for volume and weight at the end of the experiment. Tumor tissues were tested for terminal nucleotidyl transferase-mediated nick end labeling (TUNEL) and immunohistochemistry.

RESULTS

The combination of triptolide plus IR reduced cell survival to 21% and enhanced apoptosis, compared with single treatment. In vivo, tumor growth of AsPC-1 xenografts was reduced further in the group treated with triptolide plus IR compared with single treatment. TUNEL and immunohistochemistry of caspase-3 cleavage in tumor tissues indicated that the combination of triptolide plus IR resulted in significantly enhanced apoptosis compared with single treatments.

CONCLUSIONS

Triptolide in combination with ionizing radiation produced synergistic antitumor effects on pancreatic cancer both in vitro and in vivo and seems promising in the combined modality therapy of pancreatic cancer.

(5R)-5-hydroxytriptolide (LLDT-8) protects against bleomycin-induced lung fibrosis in mice

AIM

To study the protective effects of a triptolide-derived, novel compound, (5R)-5-hydroxytriptolide (LLDT-8), on bleomycin-induced lung fibrosis.

METHODS

C57BL/6 mice received an intratracheal injection of bleomycin and were then treated with LLDT-8 (0.5, 1, 2 mg/kg, ip) once daily for 7 or 14 consecutive days. The body weight loss and lung index augmentation was observed; the inflammatory response including differential cells counts of neutrophils, macrophages, and lymphocytes in the bronchoalveolar lavage fluid (BALF), superoxide dismutase (SOD), and malondialdehyde (MDA) level in the lung homogenates was detected, and the fibrosis extent was evaluated by hydroxyproline content and histopathological changes in the lungs. In addition, the pro-inflammatory and pro-fibrotic cytokines, tumor necrosis factor-alpha (TNF-alpha), interleukin-4 (IL-4), and transforming growth factor-alpha (TGF-alpha) production in the lungs were measured.

RESULTS

LLDT-8 alleviated the body weight loss and lung index increase caused by bleomycin, reduced neutrophils and lymphocytes in the BALF, promoted SOD activity, decreased MDA production, and inhibited the hydroxyproline level and the amelioration of lung tissue histological damage. Moreover, LLDT-8 suppressed TNF-alpha, IL-4, and TGF-beta production in the lung homogenates.

CONCLUSION

LLDT-8 showed protective effects against bleomycin-induced lung fibrosis, and the results suggested the potential role of LLDT-8 in the treatment of this disease.

Triptolide suppresses IL-1beta-induced chemokine and stromelysin-1 gene expression in human colonic subepithelial myofibroblasts

AIM

To examine the inhibitive effects of triptolide on the expression of IL-8, monocyte chemotactic protein (MCP)-1, and matrix metalloproteinases (MMP)-3 in subepithelial myofibroblasts (SEMF) stimulated with IL-1beta.

METHODS

SEMF cultures were established from normal colons in patients who underwent gut resection for colorectal carcinoma. Chemokine and MMP-3 expressions were determined by ELISA and RT-PCR. The cytosolic amount of phosphorylation of I kappa B-alpha(p-I kappa B-alpha) was determined by Western blotting. The DNA binding capacity of NF-kappa B was evaluated by electrophoretic mobility shift assays.

RESULTS

IL-1beta stimulated protein and mRNA expression of IL-8, MCP-1, and MMP-3 in SEMF. Triptolide inhibited these effects of IL-1beta in a dose-dependent manner. Mechanistic studies revealed that triptolide markedly decreased IL-1beta -induced NF-kappa B DNA binding capacity and cytosolic amount of p-I kappa B-alpha. These results showed that triptolide inhibited IL-1beta -induced chemokine and MMP-3 expression in SEMF through the NF-kappa B pathway.

CONCLUSION

Triptolide inhibited IL-1beta -induced chemokine and MMP-3 expression in SEMF by preventing the phosphorylation of I kappa B-alpha.

Clinical trial of Tripterygium Wilfordii Hook F. in human kidney transplantation in China

OBJECTIVE

In this study, the effects of Triptergium Wilfordii Hook F.(T II) were assessed on human kidney allograft rejection and long-term survival.

METHODS

This study compared treatment with T II(T II group, n=121) to that without T II(control group, n=102) among adult first cadaveric renal transplant recipients. The T II cohort of 121 recipients were divided into a regular dosage group (n=82) and a double dosage group (n=39). No antibody induction was administered to any patient.

RESULTS

Biopsy-proven early acute allograft rejection occurred in 4.1% of patients in the T II group versus 24.5% of patients in the control group. No rejection or repeated rejections occurred in the double dosage group at 3 months after transplantation. Acute rejection episodes were milder in the T II than the control group. The incidence of CD25+ cells>10/ mm3 in the allografts at 3 months after transplantation was lower in the T II group than the control group, 15% and 50%, respectively. All patients tolerated T II well over the 5 years of this study. The 5-year graft survival censored for death with function was 96.7% in the T II group and 80.4% in the control group.

CONCLUSION

T II was effective to prevent renal allograft rejection and increase long-term renal allograft survival among adult cadaveric renal transplant recipients.

Mechanism of triptolide-induced apoptosis: effect on caspase activation and Bid cleavage and essentiality of the hydroxyl group of triptolide

Triptolide is a compound extracted from the Chinese herb Tripterygium wilfordii Hook. f. Triptolide has potent anticancer activity. However, the mechanisms by which triptolide exerts its anticancer activities remain unclear. To explore the molecular mechanisms involved in the anticancer activity of triptolide, we have examined the effect of triptolide on the growth of pancreatic carcinoma PANC-1 and cervical adenocarcinoma HeLa cells. We found that treatment of both HeLa and PANC-1 cells with triptolide potently suppressed cell growth and induced apoptosis, indicated by nuclear fragmentation and blebbing. In both HeLa and PANC-1 cells, apoptosis induced by triptolide was associated with activation of both caspase-3 and caspase-8, and cleavage of poly(ADP-ribose) polymerase and Bid. Moreover, in HeLa cells, caspase-9 is also significantly activated in response to triptolide. Overexpression of Bcl-2 in HeLa cells substantially attenuated triptolide-induced apoptosis. Interestingly, substitution of the 14-OH of triptolide with an acetyl group abrogated both its anticancer and its antiinflammatory activities. Our studies suggest that triptolide may exert its anticancer effects by initiating apoptosis through both death-receptor- and mitochondria-mediated pathways. Our results indicate that both the apoptosis-promoting and the antiinflammatory activities of triptolide depend on the 14-OH group.