Prediction of Human Pharmacokinetics of E0703, a Novel Radioprotective Agent, Using Physiologically Based Pharmacokinetic Modeling and an Interspecies Extrapolation Approach.

E0703, a new steroidal compound optimized from estradiol, significantly increased cell proliferation and the survival rate of KM mice and beagles after ionizing radiation. In this study, we characterize its preclinical pharmacokinetics (PK) and predict its human PK using a physiologically based pharmacokinetic (PBPK) model. The preclinical PK of E0703 was studied in mice and Rhesus monkeys. Asian human clearance (CL) values for E0703 were predicted from various allometric methods. The human PK profiles of E0703 (30 mg) were predicted by the PBPK model in Gastro Plus software 9.8 (SimulationsPlus, Lancaster, CA, USA). Furthermore, tissue distribution and the human PK profiles of different administration dosages and forms were predicted. The 0.002 L/h of CL and 0.005 L of Vss in mice were calculated and optimized from observed PK data. The plasma exposure of E0703 was availably predicted by the CL using the simple allometry (SA) method. The plasma concentration-time profiles of other dosages (20 and 40 mg) and two oral administrations (30 mg) were well-fitted to the observed values. In addition, the PK profile of target organs for E0703 exhibited a higher peak concentration (Cmax) and AUC than plasma. The developed E0703-PBPK model, which is precisely applicable to multiple species, benefits from further clinical development to predict PK in humans.

Author Correction: Ophiopogonin D maintains Ca2+ homeostasis in rat cardiomyocytes in vitro by upregulating CYP2J3/ EETs and suppressing ER stress.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

[Effect of clinical doses of Realgar-Indigo Naturalis formula and large-dose of realgar on CYP450s of rat liver].

To investigate the effect of clinical dose of Realgar-Indigo Naturais formula (RIF) and large-dose of Realgar on main drug-metabolizing enzymes CYP450s of rat liver, as well as its regulatory effect on mRNA expression. Wistar rats were administrated orally with tested drugs for 14 days. A Cocktail method combined with HPLC-MS/MS was used in the determination of 4 cytochrome P450 isozymes (CYP1A2, CYP2B, CYP3A and CYP2C) in liver of the rats, and the mRNA expression levels of the above subtypes were detected by real-time fluorescent quantitative PCR. The results showed that RIF can significantly induce CYP1A2 and CYP2B enzyme activity, and inhibit CYP3A enzyme activity. This result was consistent with the mRNA expression. However, its single compound showed weaker or even contrary phenomenon. Different doses of Realgar also showed significant inconsistencies on CYP450 enzymes activity and mRNA expression. These phenomena may be relevant with RIF compatibility synergies or toxicity reduction. The results can also prompt drug interactions when RIF is combined with other medicines in application.

[Protective effect of ginsenoside Rb1 on doxorubicin-induced myocardial autophagy].

Ginsenoside Rb1 (Rb1), which is one of the main ingredients derived from Panax ginseng, has been found to have extensive pharmacological activities including antioxidant, anti-inflammatory, anticancer properties. In this study, the effect of Rb1 on doxorubicin-induced myocardial autophagy was studied with H9c2 as the study object. CCK-8 method, transmission electron microscope observation, fluorescence staining observation and Western blot were used to detect changes in H9c2 cell proliferation and autophagy after treatment. According to the results, doxorubicin could cause cell viability decrease, significant increase in the LC3-Ⅱ/LC3-I ratio and down-regulation of the expression of p62. Pretreatment with ginsenoside Rb1 inhibited cell viability decrease and increase in doxorubicin-induced autophagic structure and LC3-Ⅱ/LC3-I ratio, and down-regulation of the expression of p62. In conclusion, doxorubicin could induce H9c2 cell death and induce autophagy, and ginsenoside Rb1 showed a protective effect on DOX-induced cardiotoxicity, which may be correlated with suppression of DOX-induced autophagy.

Ferulic acid prevents LPS-induced up-regulation of PDE4B and stimulates the cAMP/CREB signaling pathway in PC12 cells.

AIM: Phosphodiesterase 4 (PDE4) isozymes are involved in different functions, depending on their patterns of distribution in the brain. The PDE4 subtypes are distributed in different inflammatory cells, and appear to be important regulators of inflammatory processes. In this study we examined the effects of ferulic acid (FA), a plant component with strong anti-oxidant and anti-inflammatory activities, on lipopolysaccharide (LPS)-induced up-regulation of phosphodiesterase 4B (PDE4B) in PC12 cells, which in turn regulated cellular cAMP levels and the cAMP/cAMP response element binding protein (CREB) pathway in the cells. METHODS: PC12 cells were treated with LPS (1 µg/mL) for 8 h, and the changes of F-actin were detected using laser scanning confocal microscopy. The levels of pro-inflammatory cytokines were measured suing ELISA kits, and PDE4B-specific enzymatic activity was assessed with a PDE4B assay kit. The mRNA levels of PDE4B were analyzed with Q-PCR, and the protein levels of CREB and phosphorylated CREB (pCREB) were determined using immunoblotting. Furthermore, molecular docking was used to identify the interaction between PDE4B2 and FA. RESULTS: Treatment of PC12 cells with LPS induced thick bundles of actin filaments appearing in the F-actin cytoskeleton, which were ameliorated by pretreatment with FA (10-40 µmol/L) or with a PDE4B inhibitor rolipram (30 µmol/L). Pretreatment with FA dose-dependently inhibited the LPS-induced production of TNF-α and IL-1ß in PC12 cells. Furthermore, pretreatment with FA dose-dependently attenuated the LPS-induced up-regulation of PDE4 activity in PC12 cells. Moreover, pretreatment with FA decreased LPS-induced up-regulation of the PDE4B mRNA, and reversed LPS-induced down-regulation of CREB and pCREB in PC12 cells. The molecular docking results revealed electrostatic and hydrophobic interactions between FA and PDE4B2. CONCLUSION: The beneficial effects of FA in PC12 cells might be conferred through inhibition of LPS-induced up-regulation of PDE4B and stimulation of cAMP/CREB signaling pathway. Therefore, FA may be a potential therapeutic intervention for the treatment of neuroinflammatory diseases such as AD.

Ophiopogonin D maintains Ca2+ homeostasis in rat cardiomyocytes in vitro by upregulating CYP2J3/EETs and suppressing ER stress.

AIM: CYP2J3 in myocardium metabolizes arachidonic acid to 4 regioisomeric epoxyeicosatrienoic acids (EETs), which have diverse biological activities in rat heart. In this study we examined whether CYP2J3 was involved in cardioprotective effects of ophiopogonin D (OPD), a steroidal glycoside isolated from Chinese herb Radix ophiopogonis. METHODS: Rat cardiomyoblast cell line (H9c2 cells) was tested. Intracellular Ca(2+) concentrations ([Ca(2+)]i) were measured using Fluo-4/AM. The expression of calcium-regulating molecules and ER stress signaling molecules was measured with qRT-PCR and Western blot analyses. Cell apoptosis was quantified with Hoechst 33258 staining and TUNEL assay. The level of 14,15-DHET, a stable metabolite of 14,15-EET, was assessed with ELISA. RESULTS: Angiotensin II (10(-6) mol/L) significantly decreased the expression of calcium-regulating molecules (SERCA2a, PLB, RyR2 and FKBP12.6), and elevated [Ca(2+)]i in H9c2 cells. Furthermore, angiotensin II markedly increased the expression of ER stress signaling molecules (GRP78, CHOP, p-JNK and cleaved caspase-12) and ER stress-mediated apoptosis. OPD (100, 250 and 500 nmol/L) dose-dependently increased CYP2J3 expression and 14,15-DHET levels in normal H9c2 cells. Pretreatment of H9c2 cells with OPD suppressed angiotensin II-induced abnormalities in Ca(2+) homeostasis, ER stress responses and apoptosis. Overexpression of CYP2J3 or addition of exogenous 14,15-EET also prevented angiotensin II-induced abnormalities in Ca(2+) homeostasis, whereas transfection with CYP2J3 siRNA diminished the effects of OPD on Ca(2+) homeostasis. Furthermore, the intracellular Ca(2+) chelator BAPTA suppressed angiotensin II-induced ER stress responses and apoptosis in H9c2 cells. CONCLUSION: OPD is a novel CYP2J3 inducer that may offer a therapeutic benefit in treatment of cardiovascular diseases related to disturbance of Ca(2+) homeostasis and ER stress.

Ginkgolide B protects human umbilical vein endothelial cells against xenobiotic injuries via PXR activation.

AIM: Pregnane X receptor (PXR) is a nuclear receptor that regulates a number of genes encoding drug metabolism enzymes and transporters and plays a key role in xeno- and endobiotic detoxification. Ginkgolide B has shown to increase the activity of PXR. Here we examined whether ginkgolide B activated PXR and attenuated xenobiotic-induced injuries in endothelial cells. METHODS: Human umbilical vein endothelial cells (HUVECs) were treated with ginkgolide B. The expression of PXR, CYP3A4, MDR1, VCAM-1, E-selectin and caspase-3 were quantified with qRT-PCR and Western blot analysis. Cell apoptosis was analyzed with flow cytometry. Fluorescently labeled human acute monocytic leukemia cells (THP-1 cells) were used to examine cell adhesion. RESULTS: Ginkgolide B (30-300 µmol/L) did not change the mRNA and protein levels of PXR in the cells, but dose-dependently increased nuclear translocation of PXR protein. Ginkgolide B increased the expression of CYP3A4 and MDR1 in the cells, which was partially reversed by pretreatment with the selective PXR signaling antagonist sulforaphane, or transfection with PXR siRNA. Functionally, ginkgolide B dose-dependently attenuated doxorubicin- or staurosporine-induced apoptosis, which was reversed by transfection with PXR siRNA. Moreover, ginkgolide B suppressed TNF-α-induced THP-1 cell adhesion and TNF-α-induced expression of vascular adhesion molecule 1 (VCAM-1) and E-selectin in the cells, which was also reversed by transfection with PXR siRNA. CONCLUSION: Ginkgolide B exerts anti-apoptotic and anti-inflammatory effects on endothelial cells via PXR activation, suggesting that a PXR-mediated endothelial detoxification program may be important for protecting endothelial cells from xeno- and endobiotic-induced injuries.

[3D evaluation model for drug hepatotoxicity testing on HepG2 cells and its application in drug safety evaluation].

3D in vitro toxicity testing model was developed by magnetic levitation method for culture of the human hepatoma cell line HepG2 and applied to evaluate the drug hepatotoxicity. After formation of stable 3D structure for HepG2 cells, their glycogen storage capacity under 2D and 3D culture conditions were detected by immunohistochemistry technology, and the mRNA expression levels of phase Ⅰ and Ⅱ drug metabolism enzymes, drug transporters, nuclear receptors and liver-specific marker albumin(ALB) were compared between 2D and 3D culture conditions by using RT-PCR method. Immunohistochemistry results showed that HepG2 cells had abundant glycogen storage capacity under 3D culture conditions, which was similar to human liver tissues. The mRNA expression levels of major drug metabolism enzymes, drug transporters, nuclear receptors and ALB in HepG2 cells under 3D culture conditions were up-regulated as compared with 2D culture conditions. For drug hepatotoxicity evaluation, the typical hepatotoxic drug acetaminophen(APAP), and most reported drugs Polygonum multiflorum Thunb.(Chinese name He-shou-wu) and Psoraleae corylifolia L.(Chinese name Bu-gu-zhi) were selected for single dose and repeated dose(7 d) exposure. In the repeated dose exposure test, 3D HepG2 cells showed higher sensitivity. This established 3D HepG2 cells model with magnetic levitation 3D culture techniques was more close to the human liver tissues both in morphology and functions, so it was a better 3D hepatotoxicity evaluation model.

[Effects of aqueous extract of Cassiae Semen on activity hepatic microsomal CYP450 isozymes in rats].

To study the effect of aqueous extract of Cassiae Semen on the activity, mRNA and protein expressions of cytochrome P450(CYP450) system in rat liver microsomes, microsomes of rat liver were prepared after the oral administration with aqueous extract of Cassiae Semen for 14 days. The enzyme activity was quantified by Cocktail method. Meanwhile, the mRNA and protein expressions of CYP1A2, CYP2B1, CYP2C11, CYP2D2, CYP2E1 and CYP3A1 in the livers were detected by RT-PCR and Western blot. The result of this experiment was that aqueous extract of Cassiae Semen obviously induced the enzyme activities of CYP1A2, CYP2B1, CYP2C11, CYP2D2, CYP2E1 and CYP3A1. Low dose of aqueous extract of Cassiae Semen significantly reduced the activity of CYP2D2, but the activity of CYP2D2 was significantly induced by middle dose and high dose of aqueous extract of Cassiae Semen. These subtypes were increased in a dose-dependent manner except for CYP3A1. The mRNA levels of CYP1A2, CYP2C11, CYP2D2 and CYP2E1 were also induced in rats treated with aqueous extract of Cassiae Semen, but with no significant effect in CYP2B1 and CYP3A1 mRNA expressions. The protein levels of CYP2C11 and CYP2E1 were also induced in rats treated with aqueous extract of Cassiae Semen, but with no significant difference. Since the enzyme activity, mRNA and protein expressions of CYP450, particularly CYP2C11and2E1subtypes, were induced or inhibited by aqueous extract of Cassiae Semen to varing degrees, suggesting the potential drug-drug interactions should be concerned.

Ferulic acid alleviates Aß25-35- and lipopolysaccharide-induced PC12 cellular damage: a potential role in Alzheimer's disease by PDE inhibition.

OBJECTIVE: Phosphodiesterase (PDE) plays an important role in the pathogenesis of Alzheimer's disease (AD). Ferulic acid (FA) has a therapeutic benefit in the treatment of AD. We investigated whether this therapeutic effect is based on the modulation of the PDE/cyclic adenosine monophosphate (cAMP) pathway. In the present study, we investigated whether FA could abrogate Aß25-35- and lipopolysaccharide-induced cellular damage. MATERIALS AND METHODS: Cell viability, superoxide production, and the levels of inflammatory factors were investigated. We further investigated the intracellular levels of cAMP and Ca2+, both of which are associated with PDE activity. Furthermore, molecular docking was used to identify the binding mode between phosphodiesterase 4B2 (PDE4B2) and FA. RESULTS: Pretreatment with FA significantly maintained cell viability, increased the levels of superoxide dismutase, and inhibited production of TNF-α and IL-1ß induced by Aß25-35. Moreover, pretreatment with FA increased the intracellular levels of cAMP and decreased the intracellular levels of Ca2+. The docking results also showed that FA has the potential to inhibit PDE4B2 activity. CONCLUSIONS: Taken together, our results suggested that one of the therapeutic effects of FA on AD was potentially mediated by modulating the PDE/cAMP pathway.

[Cardiotoxicity study of Shenfu compatibility in rats based on metabonomics].

To research the effect of Ginseng Radix et Rhizoma and Aconiti Lateralis Radix Praeparata compatibility on cardiac toxicity in rats by UPLC-Q-TOF/MS, and explore the endogenous markers and molecule mechanism. Different compatibility of Shenfu decoction were given to male Wistar rats at dosage of 20 g · kg(-1) for 7 days, collected the serum, and analyze the endogenous metabolites effected by Shenfu formulation by principal component analysis and partial least-squares analysis. Results showed that content of glutathione, phosphatidylcholine and citric acid decreased in mixed-decoction group, while ascorbic acid, uric acid, D-galactose, tryptophan, L-phenylalanine increased. The results showed cardiac toxicity of Aconiti Lateralis Radix Praeparata in Shenfu mixed-decoction. Shenfu co-decoction group showed a similar or weaker trend compared with control group, but most of them do not have a statistically significant. The results indicated the scientific basis of Shenfu compatibility by comparison of co-decoction group with mixed-decoction group. Shenfu compatibility can reduce cardiac toxicity induced by Aconiti Lateralis Radix Praeparata, and citric acid, glutathione, phosphatidyl choline, uric acid might be regarded as potential markers of cardiotoxicity.

[Preliminary study on hepatotoxicity induced by dioscin and its possible mechanism].

Dioscin has a wide range of biological effects and broad application prospects. However the studies concerning the toxicology and mechanism of dioscin is small. This article is to study the hepatotoxicity of dioscin and the effect of dioscin treatment on expression of aryl hydrocarbon receptor (AhR) mRNA and CYP1A mRNA and protein in HepG2 cells in vitro. Dioscin 0.5-32 µmol · L(-1) exposed to HepG2 cells for 12 h, cell viability was examined by CCK-8 assay and the release rate of lactate dehydrogenase (LDH) was to evaluate cell membrane damage. HepG2 cells morphologic changes were quantified by inverted Microscope, and the effect on production of reactive oxygen species (ROS) was detected by flow cytometry. The mRNA expression of CYP1A and AhR was evaluated by RT-RCR. The protein expression of CYP1A1 was detected by western blot. The cell viability was significantly inhibited after HepG2 cells were exposed to dioscin 0.5-32 µmol · L(-1). Compared with the control, the LDH release rate and ROS were significantly increased. The expression of CYPlA and AhR mRNA was increased. The expression of CYP1Al protein was increased after dioscin treatment, and resveratrol, an AhR antagonist, could downregulate the expression of CYP1A1. It follows that large doses dioscin has potential hepatotoxicity. The possible mechanism may be dioscin can active aryl hydrocarbon receptor (AhR) and induce the expression of CYP1A.

[Effects of Reduning injection on activity of hepatic microsomal CYP450 isozymes in rats].

To research the influence of Reduning injection on the activity and mRNA expression of cytochrome P450 (CYP450) system in rat liver microsomes. Rat liver microsomes were prepared after a seven-days continuous administration of Reduning injection. An HPLC-MS method was applied to determine the specific metabolites of CYP450 probe substrates in rat liver microsomal incubations. The activity of CYP450 isozymes were represented by the formation of metabolites. The Real-time quantitative polymerase chain reaction (Q-PCR) was applied to determine the mRNA expression levels of CYP450. Reduning injection significantly reduced the activity of CYP2B1, 2C12, 2C13 (P < 0.01), but did not affect CYPlA2; low dose and high dose of Reduning injection had an inhibition trend on the activity of CYP2D2, but did not statistically differ from control group; low dose of Reduning injection significantly induced the activity of CYP3A1 (P < 0.01), high dose of Reduning injection had an induce trend on the activity of CYP3A1, but did not statistically differ from control. At the mRNA level, low and high dose of Reduning injection had an induce trend on the expression of CYP1A2, 2C11, 2D1, 2E1, 3A1, but did not statistically differ from control. Reduning injection significantly induced the activity of CYP2B1. Reduning injection significantly induced the activity of CYP3A1 in mRNA expression and enzyme activity levels, which may result adverse drug reaction after being combined with macrolides antibiotics. Reduning injection significantly reduced the activity of CYP2B1, 2C12, 2C13, 2D2 in enzyme activity levels, when combined with other drugs, it should be fully taken into account of the possible drug-drug interaction in order to avoid adverse side effects.

[Effect of Siwu decoction on function and expression of P-glycoprotein in Caco-2 cells].

To study the effect of Siwu decoction on the function and expression of P-glycoprotein (P-gp) in Caco-2 cells. The Real-time quantitative poly-merase chain reaction (Q-PCR) was used to analyze the mRNA expression of MDR1 gene in Caco-2 cells. Flow cytometer was used to study the effect of Siwu decoction on the uptake of Rhodamine 123 in Caco-2 cells, in order to evaluate the efflux function of P-gp. Western blotting method was used to detect the effect of Siwu decoction on the P-gp protein expression of Caco-2 cells. Compared with the blank control group, after Caco-2 incubation with Siwu decoction at concentrations of 3.3, 5.0, 10.0 g x L(-1) for 24, 48, 72 h, the mRNA expression of MDR1 was up-regulated, suggesting the effect of Siwu decoction in inducing the expression of MDR1. After the administration with Siwu decoction in Caco-2 cells for 48 h, the uptake of Rhodamine 123 in Caco-2 cells decreased by respectively 16.6%, 22.1% (P < 0.05) and 45.4% (P < 0.01), indicating that the long-term administration of Siwu decoction can enhance the P-gp efflux function of Caco-2 cells. After the incubation of Caco-2 cells with Siwu decoction for 48 h, the P-gp protein expression on Caco-2 cell emebranes, demonstrating the effect of Siwu decoction in inducing the protein expression of P-gp.

[Pharmacology research on PXR as a potential target in screening bioactive components of Chinese material medica].

Pregnane X receptor (PXR) is key transcription factors which mainly regulate the expression of CYP3A genes. At the molecular level, PXR has been revealed the protection mechanism of the body against xenochemicals and a major mode of the drug-drug interactions. Besides playing an important role in drug metabolism and interactions, PXR and its target genes also play an important role in maintaining normal physiological function and homeostasis. Therefore, it is necessary to study the regulation of PXR and its related pharmacological effects of TCM and natural products, and to provide new clues for the new pharmacological pathway.

[Screening active components in compound danshen based on PXR-CYP3A4: an experimental study].

OBJECTIVE: To screen active components in Compound Danshen (CD) based on pregnane X receptor-cytochrome P450 3A4 (PXR-CYP3A4). METHODS: By using PXR-CYP3A stable transfection human hepatoblastoma G2 (HepG2) cell lines engineering cell strain combined reporter genes technology, active components that induce or inhibit PXR-CYP3A4 paths in CD were screened, and confirmed at the level of enzymic activities. The experiment was divided into the positive control group (RIF 10 micro mol/L), the DMSO group (DMSO 0.1%), each dose of treatment groups (ginsenoside Rc, Rf, Rb2, Rg2, F2, F1, tanshinone I , isoborneol 5, 10, 25, 50, 100, and 200 micro mol/L; each with six duplicates). Cells medium was removed 36, 48, and 60 h after treatment. The activity of CYP3A4 was then determined in the supernant and the fold induction was calculated. RESULTS: Compared with the DMSO group, the fold induction increased when ginsenoside Rc, Rf, Rb2, Rg2, F2, F1, tanshinone I , and isoborneol 50 and 100 micro mol/L was respectively intervened for 36, 48, and 60 h (P <0.05). When cells were treated with isoborneol 200 micro mol/L for 48 and 60 h,the fold induction of ginsenoside Rb2, Rg2, and F1 was significantly higher than that of the RIF group (P <0.05). Enzymic activity results showed that ginsenoside Rc, Rf, Rb2, F2, and F1 could increase the enzyme activity of CYP3A4 at 48 h (P <0.05). CONCLUSION: Ginsenoside Rc, Rf, Rb2, F2, F1, tanshinone I, and isoborneol in DC could induce CYP3A4 enzymes.

[Effect of Panax notoginseng saponins on liver drug metablic enzyme activity, mRNA and protein expressions in rats].

To study the effect of Panax notoginseng saponins (PNS) on liver drug metabolic enzyme activity, mRNA and protein expressions in rats. Male Wistar rats were randomly divided into nine groups. After administration of the test drugs, their liver microsomes, liver total RNA and total protein were extracted to detect the regulating effect of PNS on liver drug metabolic enzyme activity-related subtype enzymatic activity, mRNA and protein expression by substrate probe, quantitative PCR and Western Blot technology. The result of this experiment was that PNS could significantly induce CYP1A2 and CYP2E1 enzyme activity, mRNA expression, CYP2E1 protein expression level. PNS significantly induced CYP3A mRNA expression, but with no significant effect in CYP3A enzyme activity level. PNS had no significant effect CYP1A1 and CYP2B mRNA expressions and enzyme activity levels. PNS had selective regulations on different P450 subtypes, and the major subtypes were CYP1A2 and CYP2E1. In clinical practice, particularly in the combination with CYP1A2 and CYP2E1 metabolism-related drugs, full consideration shall be given to the possible drug interactions in order to avoid potential toxic and side effects. Meanwhile, whether the induction effect of CYP2E1 gets involved in ginsenoside's effect incavenging free radicals deserves further studies.

Positive benefit-risk ratio of Psoraleae Fructus: Comprehensive safety assessment and osteogenic effects in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Psoraleae Fructus (PF), the dried fruit of Psoralea corylifolia L., is a commonly used traditional medicine that has contributed to the treatment of orthopedic diseases for thousands of years in China. However, recent PF-related liver injury reports have drawn widespread attention regarding its potential hepatotoxicity risks. AIM OF THE STUDY: This study was aimed to evaluate the long-term efficacy and chronic toxicity of PF using a 26-week administration experiment on rats in order to simulate the clinical usage situation. MATERIALS AND METHODS: The PF aqueous extract was consecutively administrated to rats daily at dosages of 0.7, 2.0, and 5.6 g/kg (equivalent to 1-8 times the clinical doses for humans) for as long as 26 weeks. Samples were collected after 13, 26, and 32 weeks (withdrawal for 6 weeks) since the first administration. The chronic toxicity of PF was evaluated by conventional toxicological methods, and the efficacy of PF was evaluated by osteogenic effects in the natural growth process. RESULTS: In our experiments, only the H group (5.6 g/kg) for 26-week PF treatment demonstrated liver or kidney injury, which the injuries were reversible after 6 weeks of withdrawal. Notably, the PF treatment beyond 13 weeks showed significant benefits for bone growth and development in rats, with a higher benefit-risk ratio in female rats. CONCLUSIONS: PF displayed a promising benefit-risk ratio in the treatment and prevention of osteoporosis, a disease that lacks effective medicine so far. This is the first study to elucidate the benefit-risk balance associated with clinical dosage and long-term use of PF, thereby providing valuable insights for rational clinical use and risk control of PF.

[Screening of pregnane X receptor activation from ginsenosides].

In order to study effects of ginseng on the metabolism of drug belong to CYP3A4 substrate, screening of pregnane X receptor activation from ginsenosides was performed by reporter assay. Based on PXR-CYP3A stable translation cell lines, 13 ginsenosides were screened for pregnane X receptor activation by reporter assays, and RIF as the positive control. The effect of ginsenosides Rg1 onCYP3A4 mRNA expression was also investigated by RT-PCR. The PXR-CYP3A stable translation cell lines had good response to RIF, and the EC50 is 2.51 micro mol x L(-1). When the condition of final concentration was 10 micromol x L(-1), ginsenoside F2 and protopanaxatriol had moderate inductive effects on PXR. Panaxotriol, Rg2, pseudoginsenoside F11, Rg1, ginsenoside and Rb3 had inhibitory effects on PXR. Ginsenoside Rf1, Rg3, Rh2 and protopanaxdiol had no obvious effects on PXR. Rg1 down-regulated CYP3A4 mRNA expression in a concentration-dependent manner. Activation of pregnane X receptor by ginsenosides may influence the metabolism of drug belong to CYP3A4 substrate, and cause ginseng-drug interactions.

[Effect of shenfu injection on CYP450s of rat liver].

The paper is to report the study of the effect of Shenfu injection on the enzyme activity of liver CYP450 and its mRNA level of rat liver. Microsome of rat liver was prepared after intravenous administration of Shenfu injection for 7 days. The enzyme activity was quantified by Cocktail method. Meanwhile, the mRNA expression of CYP1A2, CYP2B1/2, CYP2C11 and CYP3A1 in the liver was detected by RT-PCR. Shenfu injection obviously induced the enzyme activities of CYP2B and CYP2C. Meantime Shenfu injection decreased the enzyme activities of CYP1A2 and CYP3A. The mRNA levels of CYP2B and CYP2C were also induced in rats treated with Shenfu injection. But it obviously inhibited the mRNA level of CYP1A2 and CYP3A. Since the enzyme activity and mRNA level were obviously changed after administration, the potential effect of drug-drug interaction should be concerned.