Oral Administration Of Triptolide Research Articles

Determination of concentrations and toxicokinetics of triptolide in plasma and liver of mice by UHPLC-MS/MS

This study aims to establish an ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS) method for determining the concentrations of triptolide(TP) in plasma and liver, and to explore the toxicokinetics of TP and the relationship between TP exposure and liver injury in C57 BL/6 mice, so as to provide reference for dissecting the toxicity mechanism of TP. The liquid chromatography was conducted with ZORBAX SB-C_(18) column(3.0 mm×100 mm, 3.5 μm) and the mobile phase of methanol-0.05 mmol·L~(-1) ammonium acetate. Electrospray ionization(ESI) and multiple reaction monitoring(MRM) mode were employed for mass spectrometry. After oral administration of TP(toxic dose 600 μg·kg~(-1)), the blood and liver tissues of the C57 BL/6 mice were collected at different time points to measure the TP concentrations in plasma and liver tissues. Furthermore, the blood biochemical indexes, including alkaline phosphatase(ALP), alanine aminotransferase(ALT), aspartate aminotransferase(AST), and total bile acid(TBA), were determined. After being processed by DAS 2.0, the experiment data showed that the TP in mice had the toxicokinetic parameters of T_(max)=5 min, C_(max)=14.38 ng·mL~(-1), t_(1/2)=0.76 h, AUC_(0-t)=5.63 h·ng·mL~(-1), MRT_(0-t)=0.56 h, and CL_(Z/F)=103.19 L·h~(-1)·kg~(-1). The trend of TP concentration in mouse liver tissue was consistent with that in plasma. The concentration of TP peaked at the time point of 5 min and then decreased until TP was completely metabolized. The plasma biochemical indexes(ALT, AST, ALP, and TBA) showed no significant changes within 3 h after TP administration. TP had high clearance rate and short residence time and did not significantly increase the blood biochemical indexes in mice. The results suggested that the exposure amount of free TP in vivo cannot directly cause liver injury, which might be caused by the binding of TP to some substances or the stimulation of inflammation and immune response.

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.

Interleukin ‐ 17 ‐ mediated immune responses in triptolide ‐ induced liver injury in mice (LB637)

The mechanisms of drug ‐ induced liver injury (DILI) have not been fully clarified. Many factors, including oxidative stress and hepatic immune response, can contribute to the pathogenesis of DILI. Interleukin (IL) ‐ 17 secreted by helper T (Th) 17 cells are critical components of immune response in DILI. Triptolide (TP) has been reported to induce hepatocyte damage with inflammatory cells infiltration in the liver. To investigate the involvement of IL – 17 ‐ mediated immune response in the TP ‐ induced hepatotoxicity, we examined the plasma transaminase, histopathological changes, hepatic frequencies of Th17 cells, hepatic expression of transcriptional factors and cytokines genes and plasma IL ‐ 17 levels after oral administration of TP (600 μg/kg) to female C57BL/6 mice for 24 h. Mice treated with TP displayed acute liver injury with significantly increased hepatic frequencies of Th17 cells, mRNA expression of retinoid ‐ related orphan receptor (ROR) ‐ γt and plasma IL ‐ 17 level as well as the plasma ALT and AST. Neutralization study using anti – IL ‐ 17 antibody ameliorated TP – induced liver injury. In contrast, when challenged by co ‐ administration of recombinant IL ‐ 17, hepatotoxicity was exacerbated in the triptolide ‐ administered mice. In summary, this report was demonstrated for the first time that IL ‐ 17 – mediated immune response is involved in the pathogenesis of TP ‐ induced liver injury in mice.Grant Funding Source: Supported by National Natural Science Foundation of China（No. No.81173651）

Preparation and optimization of triptolide-loaded solid lipid nanoparticles for oral delivery with reduced gastric irritation.

Triptolide (TP) often causes adverse reactions in the gastrointestinal tract when it is administered orally. This study aimed to prepare and optimize triptolide-loaded solid lipid nanoparticles (TP-SLN) with reduced gastric irritation. The microemulsion technique was used to formulate TP-SLN employing a five-level central composite design (CCD) that was developed for exploring the optimum levels of three independent variables on particle size, encapsulation efficiency (EE) and drug loading (DL). Quadratic polynomial models were generated to predict and evaluate the three independent variables with respect to the three responses. The optimized TP-SLN was predicted to comprise fraction of lipid of 49.73%, surfactant to co-surfactant ratio of 3.25, and lipid to drug ratio of 55.27, which showed particle size of 179.8 ± 5.7 nm, EE of 56.5 ± 0.18% and DL of 1.02 ± 0.003% that were in good agreement with predicted values. In addition, the optimized nanoparticles manifested a sustained-release pattern in vitro and were stable during 3 h of incubation in simulated gastric fluids without significant size change and the majority (91%) of the drug was protected. Furthermore, the nanoparticles did not show obvious gastric irritation caused by oral administration of TP in rats.

Early postinjury exercise reverses memory deficits and retards the progression of closed‐head injury in mice

Closed-head injury (CHI) usually involves both physical damage of neurons and neuroinflammation. Although exercise promotes neuronal repair and suppresses neuroinflammation, CHI patients currently often remain resting during the post-traumatic period. This study aimed to investigate whether and how postinjury exercise benefited the brain structure and function in mice after CHI. Closed-head injury immediately caused an elevated neurological severity score, with rapid loss of object recognition memory, followed by progressive location-dependent brain damage (neuronal loss and activation of microglia in the cortex and hippocampus). An early exercise protocol at moderate intensity (starting 2 days postimpact and lasting for 7 or 14 days) effectively restored the object recognition memory and prevented the progressive neuronal loss and activation of microglia. However, if the exercise started 9 days postimpact, it was unable to recover recognition memory deficits. In parallel, early exercise intervention drastically promoted neurite regeneration, while late exercise intervention was much less effective. We also tested the possible involvement of brain-derived neurotrophic factor (BDNF) and mitogen-activated protein kinase phosphatase-1 (MKP-1) in the exercise-induced beneficial effects. Exercise gradually restored the impact-abolished hippocampal expression of BDNF and MPK-1, while oral administration of triptolide (a synthesis inhibitor of MKP-1 and an antagonist of nuclear factor-B) before each bout of exercise blocked the restorative effects of exercise on MKP-1 and recognition memory, as well as the exercise-induced retardation of neuronal loss. Although triptolide treatment alone inhibited activation of microglia and maintained neuronal numbers, it did not recover the injury-hampered recognition memory. Overall, moderate exercise shortly after CHI reversed the deficits in recognition memory and prevented the progression of brain injury.

Prediction of the Pharmacokinetic Parameters of Triptolide in Rats Based on Endogenous Molecules in Pre-Dose Baseline Serum

BackgroundIndividual variances usually affect drug metabolism and disposition, and hence result in either ineffectiveness or toxicity of a drug. In addition to genetic polymorphism, the multiple confounding factors of lifestyles, such as dietary preferences, contribute partially to individual variances. However, the difficulty of quantifying individual diversity greatly challenges the realization of individualized drug therapy. This study aims at quantitative evaluating the association between individual variances and the pharmacokinetics.Methodology/Principal FindingsMolecules in pre-dose baseline serum were profiled using gas chromatography mass spectrometry to represent the individual variances of the model rats provided with high fat diets (HFD), routine chows and calorie restricted (CR) chows. Triptolide and its metabolites were determined using high performance liquid chromatography mass spectrometry. Metabonomic and pharmacokinetic data revealed that rats treated with the varied diets had distinctly different metabolic patterns and showed differential Cmax values, AUC and drug metabolism after oral administration of triptolide. Rats with fatty chows had the lowest Cmax and AUC values and the highest percentage of triptolide metabolic transformation, while rats with CR chows had the highest Cmax and AUC values and the least percentage of triptolide transformation. Multivariate linear regression revealed that in baseline serum, the concentrations of creatinine and glutamic acid, which is the precursor of GSH, were linearly negatively correlated to Cmax and AUC values. The glutamic acid and creatinine in baseline serum were suggested as the potential markers to represent individual diversity and as predictors of the disposal and pharmacokinetics of triptolide.Conclusions/SignificanceThese results highlight the robust potential of metabonomics in characterizing individual variances and identifying relevant markers that have the potential to facilitate individualized drug therapy.