UPLC-MS/MS determination of tanshinone ⅡA, salvianolic acid B and ginsenoside Rg₁ in Fufang Danshen preparation in rat plasma and brain tissues / 中国中药杂志

A sensitive and specific ultra-performance liquid chromatography-mass spectrometry (UPLC-MS/MS) method was developed for analysis of tanshinone ⅡA(TSⅡA), salvianolic acid B(SAB) and ginsenoside Rg₁ (GRg₁) in rat plasma and brain tissues. Male healthy Sprague-Dawley(SD) rats were orally given single dose of Fufang Danshen preparation (TS ⅡA 60 mg•kg⁻¹, SAB 300 mg•kg⁻¹, GRg₁ 150 mg•kg⁻¹, borneol 300 mg•kg⁻¹), and their blood samples and brain tissues were collected at different time points. The drug plasma and brain tissue concentrations of the three analytes were determined by UPLC-MS/MS method. Subsequently, the main pharmacokinetics parameters of plasma and brain tissues were calculated by using Phoenix WinNolin 6.1 software. The methodological test showed that all of analytes in both plasma and brain homogenate exhibited a good linearity within the concentration range(r>0.992 2). Their mean recoveries were between 58.86% and 112.1%. Intra-day and inter-day precisions of the investigated components exhibited RSD≤9.7%, and the accuracy(RE) ranged from -9.68% to 8.20% at all quality control levels. The results of accuracy and stability meet the requirements for biopharmaceutical analysis. For TSⅡA, the pharmacokinetics parameters Tmax, Cmax, AUC0-t, MRTlast in the plasma were (1.58±0.081) h, (725.4±88.20) μg•L⁻¹, (2 101.3±124.85) μg•h•L⁻¹ and (3.66±0.05) h, respectively. For SAB, the pharmacokinetics parameters Tmax, Cmax, AUC0-t, MRTlast in the plasma were (1.29±0.21) h, (307.9±46.75) μg•L⁻¹, (537.4±88.24) μg•h•L⁻¹ and (2.08±0.11) h, respectively. For GRg₁, the pharmacokinetics parameters Tmax, Cmax, AUC0-t, MRTlast in the plasma were (1.42±0.20) h, (460.38±154.60) μg•L⁻¹, (383.4±88.16) μg•h•L⁻¹ and (1.87±0.046) h, respectively. For TSⅡA, the pharmacokinetics parameters Tmax, Cmax, AUC0-t, MRTlast in the brain tissue were (0.75±0.22) h, (1.41±0.42) ng•g⁻¹, (4.34±2.48) ng•h•g⁻¹ and (4.00±1.90) h, respectively. For SAB, the pharmacokinetics parameters Tmax, Cmax, AUC0-t, MRTlast in the plasma were (1.08±0.20) h, (21.09±4.850) ng•g⁻¹, (14.83±3.160) ng•h•g⁻¹ and (0.99±0.08) h, respectively. For GRg₁, the pharmacokinetics parameters Tmax, Cmax, AUC0-t, MRTlast in the plasma were (0.50±0.16) h, (130.96±54.220) ng•g⁻¹, (136.24±34.350) ng•h•g⁻¹ and (2.87±0.33) h, respectively. The developed method was successfully applied in pharmacokinetic studies on content of TS ⅡA, SAB and GRg₁ in rat plasma and brain tissues.

Sterculic Acid and Its Analogues Are Potent Inhibitors of Toxoplasma gondii

Toxoplasmosis is a serious disease caused by Toxoplasma gondii, one of the most widespread parasites in the world. Lipid metabolism is important in the intracellular stage of T. gondii. Stearoyl-CoA desaturase (SCD), a key enzyme for the synthesis of unsaturated fatty acid is predicted to exist in T. gondii. Sterculic acid has been shown to specifically inhibit SCD activity. Here, we examined whether sterculic acid and its methyl ester analogues exhibit anti-T. gondii effects in vitro. T. gondii-infected Vero cells were disintegrated at 36 hr because of the propagation and egress of intracellular tachyzoites. All test compounds inhibited tachyzoite propagation and egress, reducing the number of ruptured Vero cells by the parasites. Sterculic acid and the methyl esters also inhibited replication of intracellular tachyzoites in HFF cells. Among the test compounds, sterculic acid showed the most potent activity against T. gondii, with an EC50 value of 36.2 μM, compared with EC50 values of 248-428 μM for the methyl esters. Our study demonstrated that sterculic acid and its analogues are effective in inhibition of T. gondii growth in vitro, suggesting that these compounds or analogues targeting SCD could be effective agents for the treatment of toxoplasmosis.

Lentivirus mediated silencing of Ubiquitin Specific Peptidase 39 inhibits cell proliferation of human hepatocellular carcinoma cells in vitro

BACKGROUND: Ubiquitin Specific Peptidase 39 (USP39) is a 65 kDa SR-related protein involved in RNA splicing. Previous studies showed that USP39 is related with tumorigenesis of human breast cancer cells. RESULTS: In the present study, we investigated the functions of USP39 in human hepatocellular carcinoma (HCC) cell line SMMC-7721. We knocked down the expression of USP39 through lentivirus mediated RNA interference. The results of qRT-PCR and western blotting assay showed that both the mRNA and protein levels were suppressed efficiently after USP39 specific shRNA was delivered into SMMC-7721 cells. Cell growth was significantly inhibited as determined by MTT assay. Crystal violet staining indicated that colony numbers and sizes were both reduced after knock-down of USP39. Furthermore, suppression of USP39 arrested cell cycle progression at G2/M phase in SMMC-7721cells. In addition, Annexin V showed that downregulation of USP39 significantly increased the population of apoptotic cells. CONCLUSIONS: All our results suggest that USP39 is important for HCC cell proliferation and is a potential target for molecular therapy of HCC.

Effects of Hydrogen Sulfide on a Rat Model of Sepsis-associated Encephalopathy / 华中科技大学学报（医学）（英德文版）

To investigate the interaction and involvement of sodium hydrosulfide (NaHS),a H2S donor,on hippocampus of rats suffering from sepsis-associated encephalopathy,rats were subjected to cecal ligation and puncture (CLP)-induced sepsis.Adult male Sprague-Dawley rats were randomly divided into four groups:Sham group,CLP group,CLP+NaHS group and CLP+aminooxyacetic acid (AOAA,an inhibitor of H2S formation) group.The four groups were observed at 3,6,9,12 h after treatment.We examined hippocampal H2S synthesis and the expression of cystathionine-β-synthetase (CBS),a major enzyme involved in the H2S synthesis in hippocampus.CBS expression was detected by reverse transcription polymerase chain reaction (RT-PCR).The concentrations of inflammatory cytokines (TNF-α,IL-1β) were determined in hippocampus by using enzyme-linked immunosorbent assay (ELISA).Neuronal damage was studied by histological examination of hippocampus.In CLP group,H2S synthesis was significantly increased in hippocampus compared with sham group and it peaked 3 h after CLP (P＜0.05).Sepsis also resulted in a significantly upregulated CBS mRNA in hippocampus.The levels of TNF-α and IL-1β in the hippocampus were substantially elevated at each time point of measurement (P＜0.05),and they also reached a peak value at about 3 h.Administration of NaHS significantly aggravated sepsis-associated hippocampus inflammation,as evidenced by TNF-α and IL-1β activity and histological changes in hippocampus.In septic rats pretreated with AOAA,sepsis-associated hippocampus inflammation was reduced.It is concluded that the rats subjected to sepsis may suffer from brain injury and elevated pro-inflammatory cytokines are responsible for the process.Furthermore,administration of H2S can increase injurious effects and treatment with AOAA can protect the brain from injury.