A new bufadienolide from Bufo gargarizans Cantor.

Bufo gargarizans Cantor (B. gargarizans) is the most widely distributed and abundant species of toad in China. Bufadienolides and indole alkaloids have cardiotonic and anti-tumor activities and are important pharmacological components of B. bufo gargarizans. In this experiment, a novel compound (1) and two known compounds (2 and 3) were isolated and identified from the dry skin of B. bufo gargarizans, both of which are bufadienolides. Various column chromatography methods were used to separate and purify the extract from the dried skin of B. bufo gargarizans. Accurate molecular weights were measured by HR-ESI-MS, and the chemical structure of the compounds was determined by NMR spectrometers. The structures were named as (2ß,5ß,16α)-2,5,16-trihydroxide bufa-14,20,22 dienolide (1), gamabufotalin (2) and desacetylbufotalin (3). In vitro cytotoxic activity assay indicated that compound 1 showed a moderate cytotoxicity against A549 cells with IC50 value of 12.65 µM.

Therapeutic effect and metabolomics mechanism of Patrinia Villosa (Thunb.) juss on liver injury in rats.

Patrinia villosa (Thunb.) Juss (P.V) is widely used in the treatment of chronic diseases, such as appendicitis, enteritis and gynecological inflammation. Modern research indicated that the herb has pharmacological effect on liver injury caused by inflammation, but the metabolomics mechanism is not clear. For the purpose of discovering the therapeutic effect and metabolomic mechanism of P.V on liver injury, 40 Sprague-Dawley (SD) rats were divided into normal group, model group, and P.V groups (0.98, 1.97, and 2.96 g/kg). The model group and P.V groups were injected intraperitoneally with 40% CCl4 (v/v, olive oil) to establish liver injury model. After administration of P.V for seven consecutive days. Therapeutic effect of P.V on liver injury rats were analyzed. P.V could decrease serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels of liver injury rats as a dose-dependent manner. Compared with the model group, the pathological analysis of liver tissue of P.V groups exhibit significant decrease tendency of hepatic tissue structure destruction, cytoplasmic vacuolation, cellular swelling, and inflammatory cell infiltration as a dose-dependent manner. 82 endogenous metabolites in rat serum and liver were analyzed by Ultra-high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). 14 metabolites in serum and 26 metabolites in liver were significantly different between the P.V group (2.96 g/kg) and the model group. Metabolic pathway analysis revealed that the main pathway including alanine, aspartate and glutamate metabolism, and TCA cycle were significantly altered. It is suggested that P.V can alleviate CCl4 induced liver injury, and its effect on metabolites may be an important mechanism of action.

Determination and Pharmacokinetic Study of Apatinib in Rat Plasma by UPLC.

In this study, a simple, sensitive, and robust analytical method based on ultra-performance liquid chromatography (UPLC) has been developed for the determination of apatinib in rat plasma using carbamazepine as internal standard (IS). After sample preparation by a simple liquid-liquid extraction, chromatography was performed on an Acquity UPLC BEH C18 column (2.1 × 50 mm, 1.7 µm particle size) and total run time was 2.0 min. The method was linear over the concentration range 5-1000 ng/mL with a lower limit of quantification of 5 ng/mL. Inter- and intraday precision were all within 6.5% and the accuracy was ≤3.5%. Recoveries of apatinib and IS were >80%. Stability studies showed that apatinib was stable under a variety of storage conditions. The method was successfully applied to a pharmacokinetic study involving oral administration of apatinib to rats.

Simultaneous determination of nintedanib and its metabolite by UPLC-MS/MS in rat plasma and its application to a pharmacokinetic study.

To establish a rapid and sensitive ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for the determination of concentration of nintedanib and its metabolite BIBF 1202 in rat plasma. The nintedanib and its metabolite and the internal standard (diazepam) were separated on an Acquity UPLC BEH C18 chromatography column (2.1 mm×50 mm, 1.7 µm) using gradient elution with a mobile phase of acetonitrile and 0.1% formic acid in water at a flow rate of 0.30 mL/min. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode to monitor the precursor-to-product ion transitions of m/z540.3→113.1 for nintedanib, m/z526.3→113.0 for BIBF 1202 and m/z285.3→193.1 for diazepam (IS) using a positive electrospray ionization interface. The method was validated for 1.0-200 ng/mL for nintedanib and 0.5-100 ng/mL for BIBF 1202 using 100 µL of plasma sample. Total time for each chromatograph was 3.0 min. The intra- and inter-day precision and accuracy of the quality control samples at low, medium, and high concentration levels exhibited relative standard deviations (RSD) <10.8% and the accuracy values ranged from -11.9% to 10.4%. The method was successfully applied to a pharmacokinetic study of nintedanib and BIBF 1202 in rats after oral administration of nintedanib.

Evaluation of the impact of cantharidin on rat CYP enzymes by using a cocktail of probe drugs.

The aim of this study was to assess the influence of cantharidin on the activities of the drug-metabolizing enzymes CYP1A2, CYP2C9, CYP2C19, CYP2D6 and CYP3A4 in rats. The activities of CYP1A2, CYP2C9, CYP2C19, CYP2D6 and CYP3A4 were measured using specific probe drugs. After pretreatment for 1week with cantharidin or physiological saline (control group) by intraperitoneal injection, probe drugs phenacetin (5.0mg/kg; CYP1A2 activity), tolbutamide (1.0mg/kg; CYP2C9 activity), omeprazole (10mg/kg; CYP2C19 activity), metoprolol (20mg/kg; CYP2D6 activity) and midazolam (10mg/kg; CYP3A4 activity) were administered to rats by oral administration. The blood was then collected at different times for ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis. The data showed that cantharidin exhibits an inhibitory effect on CYP2D6 and CYP3A4 by increasing t1/2, Cmax and AUC(0-∞), and decreasing CL/F compared with those of the control group. In addition, cantharidin has induction effect on CYP2C9 activity. However, no significant changes in CYP1A2 and CYP2C19 activities were observed. In conclusion, the results indicated that cantharidin could inhibit CYP2D6 and CYP3A4, while induce CYP2C9, which may affect the disposition of medicines primarily dependent on these pathways. Our work may be the basis of related herb-drug interactions in the clinic.