Triptolide Treatment Research Articles

Triptolide induces protective autophagy and apoptosis in human cervical cancer cells by downregulating Akt/mTOR activation.

Triptolide exhibits immunosuppressive, anti-inflammatory, antifertility and antineoplastic functions. However, the anticancer effect of triptolide on cervical cancer and the underlying mechanism remains to be fully understood. The present study assessed the mechanisms underlying the effect of triptolide on the viability and apoptosis of human cervical cancer cells. SiHa cells were treated with 12.5-100.0 nM triptolide for 12, 24 or 48 h. The present study demonstrated that triptolide inhibited viability and induced apoptosis in SiHa cells time- and dose-dependently. Furthermore, treatment with triptolide promoted autophagy and activated microtubule associated protein 1 light chain 3 α expression in SiHa cells. Triptolide treatment suppressed the expression of phosphorylated (p)-protein kinase B (Akt), p-mechanistic target of rapamycin (mTOR), and p-p70S6K, activated the expression of p-p38, mitogen-activated protein kinase (MAPK) and p53 and inhibited the expression of p-forkhead box O3 (Foxo3a) in SiHa cells. These results suggested that triptolide induces protective autophagy, suppresses cell viability and promotes apoptosis in human cervical cancer cells by inducing the autophagy-targeting phosphoinositide 3-kinase/Akt/mTOR, p38, MAPK, p53 and Foxo3a pathways.

Triptolide antagonized the cisplatin resistance in human ovarian cancer cell line A2780/CP70 via hsa-mir-6751.

We aimed to investigate the effect of triptolide on cisplatin resistance in ovarian cancer cell lines. The apoptosis of ovarian cancer cell lines A2780 and A2780/CP70 was determined by flow cytometry. Protein expression levels of Hexokinase 2 (HK2) were detected by western blot. Possible mRNAs which target HK 2 expression were predicted through online tools miRbase. Triptolide-promoted cell apoptosis of cisplatin-resistant ovarian cancer cell line A2780/CP70. Triptolide treatment sensitized the effect of cisplatin in A2780/CP70, as evidenced by decreased survival fraction of A2780/CP70 cells. Mechanically, triptolide treatment inhibited HK 2 expression in A2780/CP70 cells. In addition, Hsa-mir-6751 expression level was upregulated in A2780/CP70 cells after triptolide treatment.

Triptolide inhibits vascular endothelial growth factor-mediated angiogenesis in human breast cancer cells.

Triptolide has been demonstrated to induce tumor cell apoptosis. However, the role of triptolide in breast cancer angiogenesis remains unclear. The present study aimed to investigate the function of triptolide in breast cancer and the molecular mechanisms underlying this. The results revealed that triptolide could significantly decrease the expression of vascular endothelial growth factor A (VEGFA) in Hs578T and MDAMB231 breast cancer cells. Furthermore, human umbilical vein endothelial cells were used to perform tube formation and bromodeoxyuridine incorporation assays, which demonstrated an antiangiogenic effect of triptolide. In addition, the effect of triptolide in vivo was examined in a xenograft mouse model, which determined that VEGFA, cluster of differentiation 31 and anti-proliferation marker protein Ki67 expression in tumor sections was decreased in the triptolide treatment group compared with the control group. Western bolt analysis was performed to investigate the phosphorylation of extracellular signal-related kinase (ERK)1/2 and RAC-α serine/threonine-protein kinase after triptolide treatment, and it's effect on hypoxia inducible factor (HIF)1-α expression. The results demonstrated that triptolide suppressed ERK1/2 activation and HIF1-α expression. Furthermore, overexpression of HIF1-α could partially abrogate the inhibitory effect of triptolide on VEGFA expression. These results suggest that triptolide inhibits breast cancer cell angiogenesis in vitro and in vivo through inhibiting the ERK1/2-HIF1-α-VEGFA axis.

Biochemical and computational evaluation of Triptolide-induced cytotoxicity against NSCLC

Triptolide is the major bioactive component isolated from the Chinese Medicinal plant Tripterygium wilfordii. Despite the growing interest and the plethora of reports discussing the pharmacological activity of this diterpenoid, no clear consensus regarding its cellular targets and full mechanism of action has been reached.In the present work, a combined in vitro and in silico approach was used to evaluate the biological activity of Triptolide on Non-small cell lung cancer (NSCLC). In vitro, Triptolide treatment induced apoptosis in NSCLC cell lines and down-regulated the phosphorylation of AKT, mTOR, and p70S6K. Triptolide also impacted cellular glycolysis as well as the antioxidant response through the impairment of glucose utilization, HKII, glutathione, and NRF2 levels. Molecular docking results examined the possible interactions between Triptolide and AKT and predicted an allosteric binding to AKT-1 structure. Molecular dynamics simulations were further used to evaluate the stability of the complex formed by Triptolide’s best conformer and AKT. These findings provide an insightful approach to the anticancer effect of Triptolide against NSCLC and highlight a possible new role for AKT/mTOR HKII inhibition.

Triptolide-induced mitochondrial damage dysregulates fatty acid metabolism in mouse sertoli cells

Triptolide is a major active ingredient of tripterygium glycosides, used for the therapy of immune and inflammatory diseases. However, its clinical applications are limited by severe male fertility toxicity associated with decreased sperm count, mobility and testicular injures. In this study, we determined that triptoide-induced mitochondrial dysfunction triggered reduction of lactate and dysregulation of fatty acid metabolism in mouse Sertoli cells. First, triptolide induced mitochondrial damage through the suppressing of proliferator-activated receptor coactivator-1 alpha (PGC-1α) activity and protein. Second, mitochondrial damage decreased lactate production and dysregulated fatty acid metabolism. Finally, mitochondrial dysfunction was initiated by the inhibition of sirtuin 1 (SIRT1) with the regulation of AMP-activated protein kinase (AMPK) in Sertoli cells after triptolide treatment. Meanwhile, triptolide induced mitochondrial fatty acid oxidation dysregulation by increasing AMPK phosphorylation. Taken together, we provide evidence that the mechanism of triptolide-induced testicular toxicity under mitochondrial injury may involve a metabolic change.

Extrahepatic cytochrome P450s play an insignificant role in triptolide-induced toxicity

BackgroundTriptolide, an active ingredient of Chinese medicine plant Tripterygium wilfordii Hook.f., has been shown to exert anti-tumor, immunosuppressive, anti-inflammatory, and anti-fertility pharmacological effects. However, triptolide also causes severe side effects, which are manifested as toxicities in multiple organs. The aim of this study was to analyze the role of extrahepatic cytochrome P450 enzymes in triptolide-induced toxicity.MethodsXh-CL mouse model with normal liver, but low extrahepatic P450 expression levels was used in this study. Xh-CL mice and C57BL/6 (wildtype, WT) mice were treated with 200 μg/kg triptolide intraperitoneally every other day for 30 days. The serum levels of alanine aminotransferase (ALT), aspartate transaminase (AST), creatine (Cre), and blood urea nitrogen (BUN) were detected by kits. The changes of tissue were observed with H&E staining. Two groups of mice (Xh-CL and WT animals), were received a single dose of 1 mg/kg TP by oral gavage for pharmacokinetic analysis.ResultsXh-CL mice displayed higher serum levels of ALT, AST, Cre, and BUN compared to untreated Xh-CL mice. The organ-to-body weight ratio for spleen was high, while that for testes was low. Histopathological changes were observed in multiple organs. However, compared with triptolide-treated WT mice, no significant differences in either blood chemistry or histopathology were recorded. Furthermore, pharmacokinetic studies showed no significant differences between triptolide-treated Xh-CL and WT mice.ConclusionsOur findings suggest that sub-chronic triptolide treatment can induce toxicities in mouse kidney, spleen, and testis with or without normal local P450 functions. Therefore, extrahepatic P450s play an insignificant role in triptolide-induced toxicity.

Triptolide sensitizes breast cancer cells to Doxorubicin through the DNA damage response inhibition.

Triptolide is an active component from a Chinese herb, Tripterygium wilfordii which has been applied for treating immune-related diseases over centuries. Recently, it was reported that a variety of cancer cell lines could be sensitized to DNA-damage based chemotherapy drugs in combination with Triptolide treatment. In the present study, we show that a short time exposure (3 h) to Triptolide, which did not trigger apoptosis, could specifically increase breast cancer cells sensitivity to Doxorubicin rather than other chemotherapy drugs including Paclitaxel, Fluorouracil, and Mitomycin C. Further studies revealed Triptolide downregulated ATM expression and inhibited DNA damage response to DNA double- strand breaks. Moreover, the chemosensitization effect to Doxorubicin from Triptolide was attenuated by overexpression of ATM in breast cancer cells. Our findings suggest that Triptolide specifically chemosensitizes breast cancer cells to Doxorubicin prior to apoptosis initiation through downregulating ATM expression and inhibiting DNA damage response.

Mechanisms of Triptolide-Induced Hepatotoxicity and Protective Effect of Combined Use of Isoliquiritigenin: Possible Roles of Nrf2 and Hepatic Transporters

Triptolide (TP), the main bioactive component of Tripterygium wilfordii Hook F, can cause severe hepatotoxicity. Isoliquiritigenin (ISL) has been reported to be able to protect against TP-induced liver injury, but the mechanisms are not fully elucidated. This study aims to explore the role of nuclear transcription factor E2-related factor 2 (Nrf2) and hepatic transporters in TP-induced hepatotoxicity and the reversal protective effect of ISL. TP treatment caused both cytotoxicity in L02 hepatocytes and acute liver injury in mice. Particularly, TP led to the disorder of bile acid (BA) profiles in mice livers. Combined treatment of TP with ISL effectively alleviated TP-induced hepatotoxicity. Furthermore, ISL pretreatment enhanced Nrf2 expressions and nuclear accumulations and its downstream NAD(P)H: quinine oxidoreductase 1 (NQO1) expression. Expressions of hepatic P-gp, MRP2, MRP4, bile salt export pump, and OATP2 were also induced. In addition, in vitro transport assays identified that neither was TP exported by MRP2, OATP1B1, or OATP1B3, nor did TP influence the transport activities of P-gp or MRP2. All these results indicate that ISL may reduce the hepatic oxidative stress and hepatic accumulations of both endogenous BAs and exogenous TP as well as its metabolites by enhancing the expressions of Nrf2, NQO1, and hepatic influx and efflux transporters. Effects of TP on hepatic transporters are mainly at the transcriptional levels, and changes of hepatic BA profiles are very important in the mechanisms of TP-induced hepatotoxicity.

C-Myc-dependent repression of two oncogenic miRNA clusters contributes to triptolide-induced cell death in hepatocellular carcinoma cells

BackgroundTriptolide is a structurally unique diterpene triepoxide with potent antitumor activity. However,the effect and mechanism of triptolide on hepatocellular carcinoma (HCC) is not well studied.MethodsCells were treated with triptolide, and the anti-HCC activity of triptolide was evaluated using flow cytometry, western blot, and xenograft studies. MicroRNA microarray and quantitative reverse-transcription polymerase chain reaction was used to identify differential microRNAs induced by triptolide. Chromatin immunoprecipitation assay was employed to study the interaction between c-Myc and genomic regions of miR106b-25. MicroRNAs overexpression and knockdown experiments were performed to determine the role of these microRNAs in triptolide-induced apoptosis.ResultsTriptolide inhibited cell proliferation and induced marked apoptosis in multiple HCC cell lines with different p53 status. Several signaling molecules involved in different pathways were altered after the treatment of triptolide. Xenograft tumor volume was significantly reduced in triptolide-treated group compared with vehicle control group. Two miRNA clusters, miR-17-92 and miR-106b-25, were significantly suppressed by triptolide, which resulted in the upregulation of their common target genes, including BIM, PTEN, and p21. In HCC samples, high levels of these miRNA clusters correlated with shorter recurrence free survival. Triptolide inhibited the expression of theses miRNAs in a c-Myc-dependent manner, which enhanced triptolide-induced cell death. We further showed that triptolide down-regulated the expression of c-Myc through targeting ERCC3, a newly identified triptolide-binding protein.ConclusionsThe triptolide-induced modulation of c-Myc/miRNA clusters/target genes axis enhances its potent antitumor activity, which indicates that triptolide serves as an attractive chemotherapeutic agent against HCC.

Triptolide delays disease progression in an adult rat model of polycystic kidney disease through the JAK2-STAT3 pathway

The aim of our current study was to investigate the long-term effect and the mechanism of triptolide in an adult nonorthologous rat model of polycystic kidney disease (PKD). Male wild-type (+/+) and Cy/+ cystic Han:SPRD rats were treated with vehicle or triptolide from 4 to 16 wk of age. Rats were killed at 16 wk of age for blood, urine, and organ collection. Human-derived WT9-12 PKD cells were treated with triptolide with or without IL-6 pretreatment. Cell proliferation, apoptosis, and cytotoxicity were determined. Western blotting and immunohistochemistry analysis were performed to evaluate the activation of IL-6-JAK2-STAT3 pathway. Renal function was protected by 12 wk of triptolide treatment in cystic Han:SPRD rats as shown by reduced blood urea nitrogen, serum creatinine, and proteinuria levels. Cyst and kidney growth were also retarded by triptolide treatment in Cy/+ rats. We further found that the proliferation index was reduced by triptolide in cystic rats, which was correlated with the reduced expression of IL-6/IL-6 receptor, decreased phosphorylation of JAK2-STAT3, and increased expression of suppressor of cytokine signaling 3 (SOCS3). The inhibitory effect of triptolide was further studied in WT9-12 cells. Triptolide inhibited cell proliferation and the activation of JAK2-STAT3 pathway in PKD cells, but it increased the expression of SOCS3. Pretreatment with IL-6 attenuated the inhibitory effect of triptolide on STAT3 phosphorylation. Our study revealed a long-term beneficial effect of triptolide in PKD that was probably through inhibition of the JAK2-STAT3 pathway.

Triptolide reverses apatinib resistance in gastric cancer cell line MKN45 via inhibition of heat shock protein 70

Objective: To investigate the effect of triptolide, a specific inhibitor of heat shock protein 70 (HSP70), on apatinib resistance in gastric cancer cells line MKN45. Methods: The apatinib-resistant cells (MKN45/AR) and MKN45 parental cells were treated with apatinib, triptolide and apatinib combined with triptolide, respectively. CCK-8 assay was performed to determine the half maximal inhibitory concentration (IC(50)) of MKN45/AR and MKN45 cells in the presence of different treatment. The mRNA expression of heat shock protein gene (HSPA1A and HSPA1B) was detected by RT-PCR, while the protein expression of heat shock protein 70 was analyzed using Western blot in MKN45/AR and MKN45 cells. Results: The IC(50) values of apatinib-sensitive and apatinib-resistant MKN45 cells were 10.411 μmol/L and 70.527 μmol/L, respectively, showing a significant difference (P<0.05). The mRNA expression of HSPA1A and HSPA1B in MKN45/AR cells was significantly higher than that in MKN45 cells (P<0.001). The protein expression of heat shock protein 70 was significantly decreased after 0.25 μmol/L triptolide treatment in MKN45/AR cells (P<0.01). When heat shock protein 70 was inhibited by triptolide, the IC(50) value of apatinib in MKN45/AR cells was reduced to 11.679 μmol/L, which was significantly lower than cells treated with apatinib alone (P<0.05). Conclusions: The apatinib-resistant MKN45 cells have high levels of heat shock protein 70. Low doses of triptolide can significantly inhibit heat shock protein 70, leading to reverse the resistance phenotype of MKN45/AR cells. Therefore, inhibition of heat shock protein 70 provides a new therapy strategy for patients with apatinib resistance.

Antitumor effect of triptolide in T-cell lymphoblastic lymphoma by inhibiting cell viability, invasion, and epithelial-mesenchymal transition via regulating the PI3K/AKT/mTOR pathway.

IntroductionT-cell lymphoblastic lymphoma (T-LBL) is a widely disseminated disease worldwide. Triptolide (TPL) is purified from Chinese herb and displays anti-inflammatory, anti-fertility, anti-tumor and immunosuppressive effects.Materials and methodsHere, in vitro and in vivo experiments were conducted to investigate the anti-tumor effect of TPL treatment in T-LBL and the potential mechanism in T-LBL progression.ResultsTPL inhibited cell proliferation of T-LBL cells (Jurkat cells and Molt-3 cells) in a dose-dependent manner. Flow cytometry analysis showed that cell apoptosis rate was increased by TPL treatment. TPL also up-regulated the expression of Caspase-3, Bax and down-regulated the expression of Bcl-2, indicating that TPL promoted apoptosis in Jurkat cells. Moreover, TPL inhibited invasion ability of Jurkat cells and down-regulated the expression of MMP-3 and MMP-9 in a dose-dependent manner. The expression of Snail, Slug, Twist and Integrin αVβ6 was decreased and the expression of E-cadherin was increased by TPL treatment, indicating that TPL inhibited EMT of Jurkat cells. Apart from that, TPL treatment attenuated the phoslevels of PI3K, Akt and mTOR and suppressed AKT activation compared with control group, suggesting that TPL inhibited PI3K/Akt/mTOR signal pathway in T-LBL. In vivo experiments showed that TPL inhibited tumor growth of T-LBL and promoted apoptosis of tumor cells. The expression of PCNA, Bcl-2, Snail, p-PI3K, p-Akt and mTOR was suppressed by TPL in a dose-dependent manner, suggesting that TPL suppressed tumor growth and promoted apoptosis of tumor cells by inhibiting PI3K/Akt/mTOR signal pathway in T-LBL.ConclusionIn conclusion, TPL exerted anti-tumor effect in T-LBL by inhibiting cell viability, invasion and EMT via regulating the PI3K/AKT/mTOR pathway.

Triptolide Attenuates Renal Tubular Epithelial-mesenchymal Transition Via the MiR-188-5p-mediated PI3K/AKT Pathway in Diabetic Kidney Disease.

Triptolide possesses the trait of renal protection. Epithelial-mesenchymal transition (EMT) is closely linked to the pathogenesis of diabetic kidney disease (DKD). MicroRNAs have recently emerged as critical regulators of DKD. However, it is poorly understood whether triptolide alleviates renal EMT by regulating microRNAs in DKD. In this study, we found that triptolide decreased albuminuria, improved the renal structure and reduced renal EMT in rats with DKD. Furthermore, activation of the PI3K/AKT signaling pathway was increased in diabetic rats, which was partly reversed by triptolide. Triptolide also alleviated glucose-induced EMT in HK-2 cells in vitro. PI3K/AKT signaling pathway activation was reduced after triptolide treatment. Moreover, triptolide decreased the increase in miR-188-5p expression stimulated by high glucose levels in HK-2 cells. miR-188-5p inhibited PTEN expression by directly interacting with the PTEN 3'-untranslated region. Additionally, downregulation of miR-188-5p, which imitates the effects of triptolide, attenuated the activation of the PI3K/AKT pathway and HG-induced EMT, whereas miR-188-5p overexpression reversed the effects of triptolide on the PI3K/AKT pathway and EMT. In conclusion, we demonstrated that triptolide ameliorates renal EMT via the PI3K/AKT signaling pathway through the interaction between miR-188-5p and PTEN, indicating that miR-188-5p may be a therapeutic target of triptolide in DKD.

Triptolide inhibits donor-specific antibody production and attenuates mixed antibody-mediated renal allograft injury.

Donor-specific antibodies (DSAs) are major mediators of renal allograft injury, and strategies to inhibit DSAs are important in promoting long-term graft survival. Triptolide exhibits a wide spectrum of antiinflammatory and immunosuppressive activities, and in autoimmune diseases it inhibits autoantibody levels. In this study, we investigated the suppressive role of triptolide in the generation of DSAs in transplant recipients. We found that triptolide treatment of skin allograft recipients in mice significantly suppressed the development of circulating anti-donor-specific IgG and effectively alleviated DSA-mediated renal allograft injury, which led to prolonged allograft survival. In vitro studies revealed that triptolide inhibited the differentiation of B cells into CD138+ CD27++ plasma cells; reduced the levels of IgA, IgG, and IgM secreted by plasma cells; and repressed somatic hypermutation and class switch recombination of B cells. Moreover, triptolide-treated recipients showed reduced numbers of B cells, plasma cells, and memory B cells in spleens and decreased numbers of T, B, natural killer (NK) cells, and macrophages infiltrating grafts. These findings highlight the importance of triptolide in suppressing DSAs and establish triptolide as a novel therapeutic agent for antibody-mediated allograft rejection.

Triptolide inhibits pituitary adenoma cell viability, migration and invasion via ADAM12/EGFR signaling pathway

AimTriptolide, an effective component derived from Tripterygium wilfordii, has been well recognized to process a broad-spectrum antitumor activities in various tumor types. However, the potential role of triptolide in pituitary adenomas remains unknown. The aim of this study was to investigate the precise role of triptolide and underlying mechanism in regulating pituitary adenoma cell viability, migration and invasion. Main methodsWe use mouse pituitary adenoma cells (TtT/GF and AtT20 cells) as the experiment model and treated them with varying concentrations of triptolide. The corresponding inhibitory effects on cell viability, migration, invasion and apoptosis were examined respectively, and the underlying mechanism was determined by investigating ADAM12 (a disintegrin and metalloprotease 12)/EGFR signaling. Key findingsTriptolide significantly inhibited cell viability, migration and invasion in TtT/GF and AtT20 cells in a dose-dependent manner. Mechanistically, triptolide significantly reduced ADAM12 expression at protein levels and attenuated ADAM12/EGFR signaling. Meanwhile, triptolide treatment combined with ADAM12 silencing enhanced the suppression effects on cell viability, migration and invasion, and those effects were restored following ADAM12-rescued. Moreover, triptolide suppressed the tumorigenesis of TtT/GF and AtT20 cells in vivo. SignificanceOur research provides evidence that triptolide inhibits pituitary adenoma cell viability, migration and invasion via ADAM12/EGFR signaling pathway. These findings suggest a potential role for triptolide in treating pituitary adenomas.

The protective effects of triptolide on age-related bone loss in old male rats

BackgroundPrevious studies have showed that triptolide have a critical role in inhibiting osteoclast formation, bone resorption and attenuating regional osteoporosis. However, the protective role of triptolide on age-related bone loss has not been investigated. In the study, we assessed the effect of triptolide supplementation on bone microstructure and bone remolding in old male rat lumbars. MethodsFifty-two 22-month-old male Sprague-Dawley rats were randomly assigned to either triptolide treatment group or control group. Triptolide (15 μg/kg/d) or normal saline was administered to the rats of assigned group for 8 weeks. Lumbar bone mineral density (BMD) and bone microstructure were analyzed by micro-CT. Fluorochrome labeling of the bones was performed to measure the mineral apposition rate (MAR) and bone formation rate (BFR). Osteoclast number was also measured by TRAP staining. Plasma level of osteocalcin and tartrate-resistant acid phosphatase 5b (Tracp 5b) was also analyzed. ResultsMicro-CT results revealed that triptolide-treated rats had significant higher BMD, bone volume over total volume (BV/TV), trabecular thickness (Tb.Th), bone trabecular number (Tb.N), and lower trabecular separation (Tb.Sp) compared to the control group. Although fluorochrome labeling result showed no significant difference in MAR and BFR between the groups, triptolide decreased osteoclast number in vivo. In addition, a significant higher level of plasma Tracp 5b was observed in the triptolide-treated rats. Furthermore, triptolide also reduced the expression of receptor for activation of NF-κB ligand (RANKL) and increased osteoprotegerin (OPG) expression in the lumbars. ConclusionThese results suggested that triptolide had a protective effect on age-related bone loss at least in part by reducing osteoclast number in elder rats. Therefore, triptolide might be a feasible therapeutic approach for senile osteoporosis.

Inhibitory effect of Triperygium wilfordii polyglucoside on dipeptidyl peptidase I in vivo and in vitro

BackgroudDipeptidyl peptidase I (DPPI), a lysosomal cysteine protease is derived from granule immune cells including mast cell, neutrophils, and toxicity T cells. DPPI can activate serine proteases by removal of dipeptides from N-termini of the pro-proteases, resulting in granule immune cells activation which involved in physiological or pathological responses. Triperygium Wilfordii Polyglucoside (TWP) is one of the traditional Chinese medicines, and commonly used in rheumatoid arthritis (RA) treatment. The present study intended to evaluate the effects of TWP on DPPI activity. MethodsIn vivo and in vitro studies were carried out to investigate the functions of TWP or triptolide (TP) on DPPI activities in serum, tissues of CIA rats. Rats were divided into five groups randomly: normal group, untreated CIA rat group, TWP treatment CIA groups (the low dose 2.5mg/100g body-weight and high dose 5mg/100g body-weight), and TP treatment CIA group (4μg/100g body-weight). Arthritis development was monitored visually, and joint pathology was examined radiologically. Total protein concentrations in synovial fluids (SFs) were determined by BCA method. Serums and tissue homogenates from CIA rats were collected and DPPI activities were detected using fluorescence substrate GF-AFC. The in vitro interactions between DPPI in serums or in tissue homogenates and TWP or TP were assessed. ResultsTWP-treated CIA rats showed a significant improvement in bone erosion. TWP significantly suppressed paw swelling and total protein concentration in the SFs of CIA rats compared with untreated CIA rats. The elevated activities of DPPI in serums or tissues of CIA rats were significantly inhibited by TWP, but not by TP in vivo. The inhibitory effects of TWP on DPPI activities were also confirm by in vitro study. ConclusionOne of the therapeutic functions of TWP in RA treatment could be inhibiting DPPI activity in serums and synovial tissue produced during RA development, and then reducing inflammatory serine proteases activities and further recovering CIA rats from RA symptoms.

Triptolide induces Sertoli cell apoptosis in mice via ROS/JNK-dependent activation of the mitochondrial pathway and inhibition of Nrf2-mediated antioxidant response.

Triptolide (TP), an oxygenated diterpene, has a variety of beneficial pharmacodynamic activities but its clinical applications are restricted due to severe testicular injury. This study aimed to delineate the molecular mechanisms of TP-induced testicular injury in vitro and in vivo. TP (5-50000 nmol/L) dose-dependently decreased the viability of TM4 Sertoli cells with an IC50 value of 669.5-269.45 nmol/L at 24 h. TP (125, 250, and 500 nmol/L) dose-dependently increased the accumulation of ROS, the phosphorylation of JNK, mitochondrial dysfunction and activation of the intrinsic apoptosis pathway in TM4 cells. These processes were attenuated by co-treatment with the antioxidant N-acetyl cysteine (NAC, 1 mmol/L). Furthermore, TP treatment inhibited the translocation of Nrf2 from cytoplasm into the nucleus as well as the expression of downstream genes NAD(P)H quinone oxidoreductase1 (NQO1), catalase (CAT) and hemeoxygenase 1 (HO-1), thus abrogating Nrf2-mediated defense mechanisms against oxidative stress. Moreover, siRNA knockdown of Nrf2 significantly potentiated TP-induced apoptosis of TM4 cells. The above results from in vitro experiments were further validated in male mice after oral administration of TP (30, 60, and 120 mg·kg-1·d-1, for 14 d), as evidenced by the detected indexes, including dose-dependently decreased SDH activity, increased MDA concentration, altered testicle histomorphology, elevated caspase-3 activation, apoptosis induction, increased phosphorylation of JNK, and decreased gene expression of NQO1, CAT and HO-1 as well as nuclear protein expression of Nrf2 in testicular tissue. Our results demonstrate that TP activates apoptosis of Sertoli cells and injury of the testis via the ROS/JNK-mediated mitochondrial-dependent apoptosis pathway and down-regulates Nrf2 activation.

Triptolide suppresses growth and hormone secretion in murine pituitary corticotroph tumor cells via NF-kappaB signaling pathway

Triptolide is a principal diterpene triepoxide from the Chinese medical plant Tripterygium wilfordii Hook. f., whose extracts have been utilized in dealing with diverse diseases in traditional Chinese medicine for centuries. Recently, the antitumor effect of triptolide has been found in several pre-clinical neoplasm models, but its effect on pituitary corticotroph adenomas has not been investigated so far. In this study, we are aiming to figure out the antitumor effect of triptolide and address the underlying molecular mechanism in AtT20 murine corticotroph cell line. Our results demonstrated that triptolide inhibited cell viability and colony number of AtT20 cells in a dose- and time-dependent pattern. Triptolide also suppressed proopiomelanocortin (Pomc) mRNA expression and extracellular adrenocorticotropic hormone (ACTH) secretion in AtT20 cells. Flow cytometry prompted that triptolide leaded to G2/M phase arrest, apoptosis program and mitochondrial membrane depolarization in AtT20 cells. Moreover, dose-dependent activation of caspase-3 and decreased Bcl2/Bax proportion were observed after triptolide treatment. By western blot analysis we found that triptolide impeded phosphorylation of NF-κB p65 subunit and extracellular signal-regulated kinase (ERK), along with reduction of cyclin D1, without any impact on other NF-κB related protein expression like total p65, p50, IκB-α, p-IκB-α. Furthermore, the mouse xenograft model revealed the inhibition of tumor growth and hormone secretion after triptolide administration. Altogether this compound might be a potential pharmaceutical choice in managing Cushing’s disease.

Triptolide Restores Autophagy to Alleviate Diabetic Renal Fibrosis through the miR-141-3p/PTEN/Akt/mTOR Pathway.

Fibrosis is the major pathological feature of diabetic kidney disease (DKD). Autophagy, a process to maintain metabolic homeostasis, is obviously inhibited in DKD. Triptolide (TP) is a traditional Chinese medicine extract known for immune suppression and anti-inflammatory and anti-cancer activities. In this study, we investigated the effects of TP on autophagy and fibrosis in DKD. TP restored autophagy and alleviated fibrosis in DKD rats and high-glucose-incubated human mesangial cells. After we applied 3-methyladenine (an autophagy inhibitor) and autophagy-related gene 5-small interfering RNA (siRNA), we found that the improvement of fibrosis on TP was related to the restoration of autophagy. In addition, miR-141-3p levels were increased under high glucose but reduced after TP treatment. miR-141-3p overexpression aggravated the fibrosis and restrained the autophagy further, while miR-141-3p inhibition imitated the effects of TP. As an action target, phosphatase and tensin homolog (PTEN) showed corresponding opposite changes. After PTEN-siRNA transfection, the effects of TP on autophagy and fibrosis were inhibited. PTEN levels were downregulated, with downstream phosphorylated protein kinase B (Akt) and the mammalian target of rapamycin (mTOR) upregulated in high glucose, which were reversed by TP treatment. These findings indicate that TP alleviates fibrosis by restoring autophagy through the miR-141-3p/PTEN/Akt/mTOR pathway and is a novel therapeutic option for DKD.