Triptolide Attenuates Acute Small-for-Size Liver Graft Injury in Rats by Inhibition of Toll-like Receptor 4

Prediction of oral hepatotoxic dose of natural products derived from traditional Chinese medicines based on SVM classifier and PBPK modeling

The risk of drug-induced liver injury (DILI) poses a major challenge for development of natural products derived from traditional Chinese medicines (NP-TCMs). It is urgent to find a new method for the safety assessment of the NP-TCMs. Recent study has reported an in vitro/in silico method to estimate the acceptable daily intake of hepatotoxic compounds using support vector machine (SVM) classifier and physiologically based pharmacokinetic (PBPK) modeling. However, this method is not suitable for estimating the dosing schedule of compounds which are administered in multiple daily doses. Thus, in this study, the method mentioned above was in particular optimized, and used to estimate the hepatotoxic plasma concentrations of 17 NP-TCMs. Additionally, the oral dosing schedules of the triptolide, emodin, matrine and oxymatrine were also predicted by the SVM classifier and PBPK modeling. The optimization included that: (1) in vitro cytotoxicity data of 28 training set compounds was optimized using benchmark concentrations (BMC) modeling; (2) AUC of the training set compound was used as the in vivo metric instead of C_max to better reflect the total daily exposure of compounds which are administered in multiple daily doses; (3) using the mean AUC in plasma as in vivo metric and BMC value as in vitro metric could achieve the better toxicity separation index (0.962 vs. 0.938); (4) The TSI for C_max and BMC values was 0.985 calculated in this study, and the results indicated that BMC modeling improved the separation performance. This optimized in vitro-in vivo extrapolation (IVIVE) workflow could extrapolate in vitro BMC to blood concentrations and the oral dosing schedule which are corresponding to certain risk of hepatotoxicity. The estimated safe dosing schedule of oxymatrine by this optimized method was close to the clinical recommended dosing regimen. The results indicate that the optimized method could be used to predict the dosing schedule of compounds administered in multiple daily doses, and our optimized workflow could be helpful for the safety assessment as well as the research and development on NP-TCMs.

Protective effects of oxymatrine against lipopolysaccharide/D‑galactosamine‑induced acute liver failure through oxidative damage, via activation of Nrf2/HO‑1 and modulation of inflammatory TLR4‑signaling pathways

Oxymatrine has a variety of pharmacological functions, including anti-viral, anti-liver fibrotic, anti-cancer, anti‑bacterial, anti‑epidemic, analgesic, anti‑allergy and anti‑inflammatory properties. The present study aimed to investigate the protective effects of oxymatrine against lipopolysaccharide (LPS)/D‑galactosamine (D‑GalN)‑induced acute liver failure and the associated underlying mechanisms. Mice were administrated 4 mg/kg LPS and 600 mg/kg D‑GalN. Then, mice in the Oxymatrine group were treated with 120 mg/kg of oxymatrine for 4 weeks. Oxymatrine treatment increased survival rate, decreased plasma aspartate transaminase and alanine aminotransferase activity, increased superoxide dismutase and glutathione peroxidase and decreased malondialdehyde, tumor necrosis factor‑ and myeloperoxidase activities in mice with LPS/D‑GalN‑induced liver failure. Furthermore, Oxymatrine activated nuclear factor erythroid 2‑related factor (Nrf) 2 and heme oxygenase (HO)‑1 protein expression, and suppressed Toll like receptor (TLR)4, myeloid differentiation primary response 88 and nuclear factor‑κB protein expression in mice LPS/D‑GalN mice. Overall, the present study suggests that oxymatrine effectively attenuates LPS/D‑GalN‑induced acute liver failure by oxidative damage via activation of Nrf2/HO‑1 and modulation of TLR4‑dependent inflammatory signaling pathways.

WITHDRAWN: Toxicity of triptolide and the molecular mechanisms involved

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Triptolide inhibits CD4+ memory T cell-mediated acute rejection and prolongs cardiac allograft survival in mice

There have been numerous investigations into the immunosuppressive effects of triptolide; however, its inhibitory effects on memory T cells remain to be elucidated. Using a cluster of differentiation (CD)4⁺ memory T-cell transfer model, the aim of the present study was to determine the inhibitory effects of triptolide on CD4⁺ memory T cell-mediated acute rejection and to determine the potential underlying mechanisms. At 4 weeks after skin transplantation, mouse cervical heart transplantation was performed following the transfer of CD4⁺ memory T cells. Mice were divided into two groups: A Control [normal saline, 30 ml/kg/day; intraperitoneal injection (ip)] and a triptolide group (triptolide, 3 mg/kg/day; ip). Graft survival, pathological examination and the corresponding International Society for Heart & Lung Transplantation (ISHLT) scores were assessed 5 days following heart transplantation, and levels of interleukin (IL)-2, interferon-γ (IFN-γ), IL-10 and transforming growth factor β1 (TGF-β1) in cardiac grafts and peripheral blood were assessed using reverse transcription-quantitative polymerase chain reaction and ELISA. The duration of cardiac graft survival in the triptolide group was significantly increased compared with the control group (14.3±0.4 vs. 5.3±0.2 days; P<0.001). Further pathological examinations revealed that the infiltration of inflammatory cells and myocardial damage in the cardiac grafts was notably reduced by triptolide, and the corresponding ISHLT scores in the triptolide group were significantly lower than those of the control group (grade 2.08±0.15 vs. 3.67±0.17; P<0.001). In addition, triptolide was able to significantly reduce IL-2 and IFN-γ secretion (P<0.01), significantly increase TGF-β1 secretion in the cardiac grafts and peripheral blood (P<0.01) and increase IL-10 secretion in the cardiac grafts. Therefore, the present study suggests that triptolide inhibits CD4⁺ memory T cell-mediated acute rejection and prolongs cardiac allograft survival in mice. This effect may be mediated by the inhibition of cytokine secretion by type 1 T helper cells and promotion of regulatory T cell proliferation.

Anti-inflammatory effects of triptolide on IgA nephropathy in rats

IgA nephropathy (IgAN) is the finding of immune deposits predominantly containing polymeric IgA in the glomerular mesangium on renal biopsy. Recently studies show that inflammation may involve in the progression of renal glomerulosclerosis and tubulointerstitial scarring in IgAN. This study was designed to evaluate the renoprotective effect of triptolide on IgAN rat model. IgAN was induced in Sprague-Dawley rats by oral and intravenous immunization with BSA for 12 weeks. Rats were treated with triptolide (200 μg/kg/d intragastrically) from 12 to 28 weeks. At Week 28, the rats was sacrificed, kidneys and blood samples were collected for further analysis. Our data shown that IgAN rat model showed marked deterioration of proteinuria together with higher levels of the urine protein:creatinine ratio compared to the normal control. Animals that underwent intermittent exposure to triptolide treatment exhibited significant improvements in the functional parameters without severe side effects. Rats developing IgAN had profound mesangial proliferation and mesangial expansion, intense and diffuse glomerular IgA deposition, while triptolide treatment significantly attenuated it. We also observed that treatment with triptolide significantly decreases serum levels of IL-1β and IL-18, and may exerted anti-inflammatory effects by down-regulating NLRP3 and TLR4 expression. Our study clearly demonstrated that triptolide prevents IgAN progression via an amelioration of inflammasome-mediated proinflammatory cytokine production, thus brought a light of hope for treatment of IgAN.

Recent Advances in Traditional Chinese Medicine for Kidney Disease

Because current treatment options for chronic kidney disease (CKD) are limited, many patients seek out alternative therapies such as traditional Chinese medicine. However, there is a lack of evidence from large clinical trials to support the use of traditional medicines in patients with CKD. Many active components of traditional medicine formulas are undetermined and their toxicities are unknown. Therefore, there is a need for research to identify active compounds from traditional medicines and understand the mechanisms of action of these compounds, as well as their potential toxicity, and subsequently perform well-designed, randomized, controlled, clinical trials to study the efficacy and safety of their use in patients with CKD. Significant progress has been made in this field within the last several years. Many active compounds have been identified by applying sophisticated techniques such as mass spectrometry, and more mechanistic studies of these compounds have been performed using both in vitro and in vivo models. In addition, several well-designed, large, randomized, clinical trials have recently been published. We summarize these recent advances in the field of traditional medicines as they apply to CKD. In addition, current barriers for further research are also discussed. Due to the ongoing research in this field, we believe that stronger evidence to support the use of traditional medicines for CKD will emerge in the near future.