Wuzhi capsule increased systemic exposure to methotrexate by inhibiting the expression of OAT1/3 and P-gp.

BACKGROUND: Methotrexate (MTX) is an important anticancer agent and immunosuppressant with a narrow therapeutic window. Wuzhi capsule (WZC) is an extract of Schisandra which is widely used to treat liver diseases. Co-administration of MTX and WZC is common in the clinical setting, but research on the interaction between WZC and MTX is limited. This study aimed to investigate the effects of WZC on the pharmacokinetics of MTX in rats and to explore the role of membrane transport proteins OAT1/3 and P-gp in the interaction of these drugs. METHODS: Plasma MTX concentration was detected by ultra-performance liquid chromatography-tandem mass spectrometer (UPLC-MS/MS), and the messenger RNA (mRNA) and protein expression of OAT1/3 and P-gp was evaluated by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blotting analyses, respectively. RESULTS: The study results revealed that co-administration of WZC decreased the CLz/F and Vz/F of MTX, increased the Cmax and area under the curve [(AUC)0-24 h] of MTX, and inhibited OAT1/3 expression in the kidney and P-gp expression in the small intestine. CONCLUSIONS: The findings suggested that there is a drug interaction between WZC and MTX and that OAT1/3 in the kidney and P-gp in the small intestine may be the main targets mediating the drug interaction, and attention should be paid when they are used in combination.

Evaluation of influence of telmisartan on the pharmacokinetics and tissue distribution of canagliflozin in rats and mice.

BACKGROUND: Canagliflozin, a sodium glucose cotransporter 2 (SGLT2) inhibitor, is widely used for the treatment of type 2 diabetes mellitus. However, drug interactions with canagliflozin can affect its glucoselowering therapeutic effects or exacerbate its adverse effects. Telmisartan, an angiotensin receptor blocker (ARB), has been approved for the treatment of diabetic kidney disease. This study aimed to investigate the effects of telmisartan on the pharmacokinetics and tissue distribution of canagliflozin. METHODS: An ultra-performance liquid chromatography-tandem mass spectrometry method was successfully validated to determine the levels of canagliflozin in the plasma and tissues. The main pharmacokinetic parameters were calculated using the non-compartmental model. RESULTS: Compared with animals administered canagliflozin alone, the area under the receiver operating characteristic curve of animals co-administered telmisartan and canagliflozin was significantly increased after a single-day administration, but significantly decreased after a seven-day treatment regimen (both P<0.05). The highest concentrations of canagliflozin were detected in the kidneys, followed by the intestine, liver, heart, lung, spleen, and brain tissues. Furthermore, the concentration of canagliflozin in the heart, liver, lung, and kidney tissues at 2 hours post-administration was significantly higher in the telmisartan and canagliflozin group compared to the group treated with canagliflozin alone (P<0.05). CONCLUSIONS: A pharmacokinetic drug-drug interaction between telmisartan and canagliflozin might occur during drug co-administration.

The synergistic anti-tumor effect of schisandrin B and apatinib.

The synergistic anti-tumor effect of schisandrin B (Sch.B) and apatinib was investigated in vitro. The CCK-8 assay revealed that Sch.B enhanced the inhibition of apatinib on cell proliferation by arresting cell cycle in G0/G1 phase. Sch.B also potentiated the suppression of apatinib on cell migration and invasion, by means of wound-healing and transwell invasion assay. Flow cytometry results showed that Sch.B enhanced apoptosis induced by apatinib. The results were confirmed by western blot analysis of the proteins MMP-9, and Bax caspase-9, and -12. These results suggest that combining apatinib and Sch.B is an effective therapeutic strategy for preventing GC progression. [Formula: see text].

Effects of Silymarin on the In Vivo Pharmacokinetics of Simvastatin and Its Active Metabolite in Rats.

Herein, the effect of silymarin pretreatment on the pharmacokinetics of simvastatin in rats was evaluated. To ensure the accuracy of the results, a rapid and sensitive UPLC-MS/MS method was established for simultaneous quantification of simvastatin (SV) and its active metabolite simvastatin acid (SVA). This method was applied for studying the pharmacokinetic interactions in rats after oral co-administration of silymarin (45 mg/kg) and different concentrations of SV. The major pharmacokinetic parameters, including Cmax, tmax, t1/2, mean residence time (MRT), elimination rate constant (λz) and area under the concentration-time curve (AUC0-12h), were calculated using the non-compartmental model. The results showed that the co-administration of silymarin and SV significantly increased the Cmax and AUC0-12h of SVA compared with SV alone, while there was no significant difference with regards to Tmax and t1/2. However, SV pharmacokinetic parameters were not significantly affected by silymarin pretreatment. Therefore, these changes indicated that drug-drug interactions may occur after co-administration of silymarin and SV.

An Accurate and Effective Method for Measuring Osimertinib by UPLC-TOF-MS and Its Pharmacokinetic Study in Rats.

Osimertinib, a new-generation inhibitor of the epidermal growth factor, has been used for the clinical treatment of advanced T790M mutation-positive tumors. In this research, an original analysis method was established for the quantification of osimertinib by ultra-performance liquid chromatography with time of flight mass spectrometry (UPLC-TOF-MS) in rat plasma. After protein precipitation with acetonitrile and sorafinib (internal standard, IS), they were chromatographed through a Waters XTerra MS C18 column. The mobile phase was acetonitrile and water (including 0.1% ammonia). The relative standard deviation (RSD) of the intra- and inter-day results ranged from 5.38 to 9.76% and from 6.02 to 9.46%, respectively, and the extraction recovery and matrix effects were calculated to range from 84.31 to 96.14% and from 91.46 to 97.18%, respectively. The results illustrated that the analysis method had sufficient specificity, accuracy and precision. Meanwhile, the UPLC-TOF-MS method for osimertinib was successfully applied into the pharmacokinetics of SD rats.