Progress in the biomarker discovery for drug-induced liver injury / 药学学报

The leading cause of drug withdrawal from market and clinical trials failure is drug-induced liver injury (DILI). Varying clinical, histological and laboratory features of DILI, as well as undefined underlying mechanisms, hinder patients to be diagnosed in the early-stage of the disease and receive effective treatments. Conventional indicators, like serum transaminases and bilirubin, have inevitable limitations referring to sensitive prediction and specific detection of DILI. In order to reduce the occurrence of DILI, researchers have attempted to discover potential biomarkers with higher specificity and sensitivity from blood and urine in recent years. This article aims to review recent advances in biomarkers of DILI.

The effect of tetramethylpyrazine on the pharmacokinetics of intragastrically administered cyclosporine A in rats / 药学学报

<p><b>AIM</b>To investigate the possible effect of tetramethylpyrazine (TMP), an active ingredient of a commonly used Chinese herb, on the pharmacokinetics of cyclosporine A (CsA) by intragastric administration in rats.</p><p><b>METHODS</b>Forty male Sprague-Dawley rats were equally divided into four groups by randomized block design according to weight. On the first day, after each fasting rat was intragastrically administered CsA (10 mg x kg(-1)), blood samples (0.2 - 0.25 mL) were collected from the tail vein at 0, 1, 2, 3, 4, 6, 8, 12, 24, 36 and 48 h. From day 4 to day 8, each group began to undergo different pretreatments with intragastric administration of water, verapamil (Ver), low and high dose TMP, separately. On day 9, each group intragastrically co-administered CsA (10 mg x kg(-1)) and different pretreatment compounds mentioned above, then blood samples were collected according to the schedule of the first day. The whole blood concentration of CsA was determined by HPLC. Main pharmacokinetic parameters were calculated and compared by statistic analysis.</p><p><b>RESULTS</b>In the group of water pretreated and co-administrated with CsA, no significantly different pharmacokinetic parameters of CsA were found. After Ver pretreatment and co-administration with CsA, AUC(0-48 h) and C(max) were increased significantly (P < 0.01 and P < 0.05); T(1/2) beta and CL were markedly prolonged and decreased (P < 0.05); T(max) and V were not apparently influenced. After low dose TMP pretreatment and co-administration with CsA, there was no significant difference in the pharmacokinetic parameters of CsA, in spite of the increasing trends of AUC(0-48 h) and C(max). After high dose TMP pretreatment and co-administration with CsA, AUC(0-48 h) and C(max) of CsA were increased significantly (P < 0.01), but there was no significant change in other parameters.</p><p><b>CONCLUSION</b>It was indicated that the high dose of TMP could apparently increase the intragastric absorption extent of CsA, while almost had no effect on its elimination process.</p>

Role of bone marrow mesenchymal stem cells in the recovery of rat acute renal tubular damage / 中华肾脏病杂志

Objective To investigate whether mesenchymal stem cells can promote the recovery of acute renal tubular damage induced by mercuric chloride and to explore its possible mechanism.Methods Acute renal failure rat model was established by intraperitoneal injection of mercuric chloride.SD rats were randomly divided into three groups which were MSCs injection group, saline infusion group and normal control group.Seven days later,the changes of rat weight,survival,renal function and pathology were observed;PCNA,ED-1 and GFP were detected by immunohistochemistry; The expression of cytokines in kidney and the distribution of GFP plasmid-transfected MSCs in kidney were examined by RT-PCR.Results MSCs infusion ameliorated the decline of rat weight,survival, renal function,and pathological changes.PCNA and ED-1 positive cells in MSCs group were fewer than those in saline group.Expression of growth factors EGF,PDGF,HGF were obviously up- regulated and pre-inflammatory cytokines TNF-?was significantly reduced in MSCs-treated kidneys. GFP-labelled MSCs occurred occasionally in renal interstitium of MSCs-treated rats,but not in renal tubules.Conclusions Bone marrow mesenchymal stem cells can promote the recovery of acute renal tubular epithelial cells damage caused by mercuric chloride.The mechanism may partly depend on regulating the excretion of cytokines in renal microenvironment rather than completely depend on their differentiation to tubular cells.

Mechanism of mono-hydroxylation of daidzein in human liver microsomes / 药学学报

<p><b>AIM</b>To identify the cytochrome P450 (CYP) isoform (s) involved in daidzein mono-hydroxylated metabolites using human liver microsomes.</p><p><b>METHODS</b>Kinetic analysis of the rates of formation of mono-hydroxylated metabolites of daidzein, including 7,8,4'-trihydroxyisoflavone (7,8,4'-THI), 7,3',4'-trihydroxyisoflavone (7,3',4'-THI) and 6,7,4'-trihydroxyisoflavone (6,7,4'-THI), was performed using human liver microsomes (HLM) and recombinant enzymes at substrate concentrations ranging from 0.5 to 400 micromol x L(-1). Nine selective inhibitors or substrate probes specific for different CYP isoforms were applied for screening the isoform(s) responsible for mono-hydroxylated metabolism of daidzein.</p><p><b>RESULTS</b>Michaelis-Menten kinetic parameters were best fitted to one-component enzyme kinetic model. The mean Km (micromol x L(-1) ) and V(max) (micromol x g(-1) x min(-1)) values were 27 +/- 10 and 4. 8 +/- 2.1, 54 +/- 22 and 2.3 +/- 1.0, 51 +/- 29 and 2.2 +/- 0.8, for the formation rates of 7,8,4'-THI, 7,3',4'-THI, and 6,7,4'-THI, respectively. Furafylline, the CYP1A2 specific inhibitor, estrogen, and monoclonal antibody raised against human CYP1A2 (MAB-1A2) apparently inhibited the formation of mono-hydroxylated metabolites, The IC50 of Fur for the formation of 7,3',4'-THI, 6,7,4'-THI and 7,8,4'-THI was 1.0, 0.9 and 0. 8 mol x L(-1), respectively. The IC50 of estrogen for the formation of 7,3',4'-THI, 6,7,4'-THI and 7,8,4'-THI were 51, 60 and 64 mol x L(-1) respectively. The IC50 of MAB-1A2 for the formation of the mono-hydroxylated products was 1 mol x L(-1), but neither other selective inhibitor nor substrate probes, including coumarin (CYP2D6), sulphaphenzole ( CYP2C9/10), omeprazole ( CYP2C19), quinidine (CYP2D6), diethyldithiocarbamate (CYP2E1), troleandomycin (CYP3A4) and keteconazole (CYP3A4), did so with human liver microsomes.</p><p><b>CONCLUSION</b>The in vitro studies indicated that daidzein mono-hydroxylated products were principally metabolized by CYP1A2 in human.</p>

Determination of octreotide in human plasma by HPLC-MS with solid-phase extraction and study on the relative bioavailability of domestic and imported octreotide injections / 药学学报

<p><b>AIM</b>To establish an HPLC-MS method for determination of octreotide in plasma and study the relative bioavailability of domestic and imported octreotide injections.</p><p><b>METHODS</b>Octreotide in plasma samples were extracted with a Waters solid-phase extraction mini column. HPLC-MS was carried out using a Waters Xetrra C18 column and a mobile phase consisting of CH3 OH-1% HAc (80 : 20), the flow rate was 0.2 mL x min(-1), and the internal standard was 6, 7, 4'-OH-isoflavone, the SIR ions for quantification were m/z 1 014.4 for octreotide and m/z 317.6 for internal standard. A single dose of 200 microg of domestic or imported preparations was intramuscularly given to 18 healthy volunteers in a randomized crossover study. Octreotide concentration in plasma was determined by LC-MS method. The pharmacokinetics and bioavailability were studied.</p><p><b>RESULTS</b>The regressive curve was linear (r = 0.9997) within the range of 0.5 - 40 microg x L(-1) for octreotide. The pharmacokinetics parameters of domestic and imported injection were reply to one compartment model. The mean C(max) were (19 +/- 10) microg x L(-1) and (19 +/- 11) microg x L(-1), T(max) were (0.50 +/- 0.15) h and (0.52 +/- 0.20) h, T1/2 were (1.5 +/- 0.8) h and (1.5 +/- 0.8) h, AUC(0-7 h) were (50 +/- 25) h x microg x L(-1) and (50 +/- 25) h x microg x L(-1), respectively. The relative bioavailability of domestic to imported injection was 101% +/- 10%.</p><p><b>CONCLUSION</b>The method is accurat and sensible for assay of plasma octreotide concentration. The results of statistics showed the two preparations were bioequivalent.</p>

Immunohistologic analysis of renal peroxisome proliferator-activated receptor?expression in lupus nephritis patients / 中华风湿病学杂志

Objective To investigate the expression of peroxisome proliferator-activated receptor (PPAR?)in lupus nephritis(LN)patients and the possible mechanisms of PPAR?in the pathogenesis of LN. Method PPAR?expression was examined in 21 LN patients and 5 normal kidney biopsy specimens by im- munohistochemical method.The relationship between PPAR?expression and renal pathologic changes was an- alyzed.Results Glomerular and tubular positive staining of PPAR?in LN patients was markedly up-regulated compared with that in normal kidney specimens.The distribution and expression of PPAR?in classⅣwas sig- nificantly increased compared with that in classⅤandⅡ.The relevance assay showed that there was positive relationship between active index and glomerular PPAR?immunohistochemistry staining cell numbers(r=0.94, P＜0.01 ).Conclusion This study demonstrates in vivo that PPAR?expression is increased in active LN pa- tients with pathological active inflammation.These data suggest that the increase of PPAR?expression in renal cells may play an important role in the pathogenesis of LN.

Vasculitic lesion in idiopathic IgA nephropathy / 中华肾脏病杂志

Objective To analyze the pathological and clinical characteristics of patients with idiopathic IgA nephropathy accompanied by vasculitic/crescentic lesion (IgA-V/C). Methods Data of 222 patients diagnosed as idiopathic IgA nephropathy by renal biopsy, among them 87 cases with vasculitic/crescenlic (V/C)lesion, from our department in 2004 were analyzed retrospectively. Clinical and pathological data from patients with IgA-V/C were compared to those of non-IgA-V/C patients and of lupus nephritis (LN) patients with V/C lesion. Results Vasculitic/crescentic lesion was found in 39.19% (87/222) patients with idiopathic IgA nephropathy.And about( 14.08?12.75)% of the glomeruli was affected. It should be taken into account that there was no significant differences of clinical manifestations including blood pressure, urinary protein excretion between IgA-V/C group and non-IgA-V/C group .except serum creatinine(Scr)level which was significantly higher in IgA-V/C group. In addition, only 37.9% of IgA-V/C patients presented high Scr level,thus the lesion of V/C in idiopathic IgA nephropathy was easily overlooked. Patients with idiopathic IgA nephropathy were found to have higher percentage of glomerular sclerosis (64.86% vs 40.00%) and ratio of sclerostic glomeruli to total glomeruli [ (26.98 ?24.68)% vs (16.10 ?18.80)% ]as compared to LN group, which further predicated the progressing characteristics of IgA nephropathy. Conclusions Vasculitic/crescentic lesion is a quite common finding in idiopathic IgA nephropathy and often associated with no dramatically symptoms. It is possible for vasculitic/crescentic lesion to induce unmarked lose of nephron slowly and continually, so as to accelerate IgA nephropathy progression to end-stage renal failure.