ABSTRACT
Marsdenia tenacissima injection, a standard Marsdenia tenacissima extract (MTE), has been approved as an adjuvant therapeutic agent for various cancers. Our previous study showed that MTE inhibited the proliferation and metastasis of prostate cancer (PCa) cells. However, the underlying mechanisms and active ingredients of MTE against PCa were not completely understood. This study revealed that MTE induced significant decreases in cell viability and clonal growth in PCa cells. In addition, MTE induced the apoptosis of DU145 cells by reducing the mitochondrial membrane potential and increasing the expression of Cleaved Caspase 3/7, Cyt c, and Bax. In vivo, DU145 xenografted NOD-SCID mice treated with MTE showed significantly decreased tumor size. TUNEL staining and Western blot confirmed the pro-apoptotic effects of MTE. Network pharmacology analysis collected 196 ingredients of MTE linked to 655 potential targets, and 709 PCa-associated targets were retrieved, from which 149 overlapped targets were screened out. Pathway enrichment analysis showed that the HIF-1, PI3K-AKT, and ErbB signaling pathways were closely related to tumor apoptosis. Western blot results confirmed that MTE increased the expression of p-AKTSer473 and p-GSK3βSer9, and decreased the expression of p-STAT3Tyr705in vitro and in vivo. A total of 13 compounds in MTE were identified by HPLC-CAD-QTOF-MS/MS and UPLC-QTOF-MS/MS. Molecular docking analysis indicated that six compounds may interact with AKT, GSK3β, and STAT3. In conclusion, MTE induces the endogenous mitochondrial apoptosis of PCa by regulating the AKT/GSK3β/STAT3 signaling axis, resulting in inhibition of PCa growth in vitro and in vivo.
Subject(s)
Mice , Animals , Male , Humans , Mice, Inbred NOD , Mice, SCID , Marsdenia , Proto-Oncogene Proteins c-akt , Glycogen Synthase Kinase 3 beta , Molecular Docking Simulation , Phosphatidylinositol 3-Kinases , Tandem Mass Spectrometry , Prostatic Neoplasms , Apoptosis , STAT3 Transcription FactorABSTRACT
Objective: To establish a method using gas chromatography for the determination of the residual chloroform in the medical polylactic acid membrane. Methods: The direct aqueous injection gas chromatographic method was established for the determination using RESTEK RTX capillary-column chromatography with the electron capture detector(ECD) at 270 ℃ and with the column at 85 ℃,maintained for 3 min. The split ratio of sampling was 10∶1. The injector temperature was 200 ℃. The high purity nitrogen was used as the carrier gas with the flow of 1. 0 ml /min. The injection volume was 1 μl. Results: The calibration curve showed a good linearity within the range of 25-2 000 ng /ml (r = 0. 999 9). The limit of detection was 1. 50 ng /ml,and the limit of quantitation was 4. 62 ng /ml. The average recovery rate was 98. 35％,RSD = 1. 98％. Conclusion: Gas chromatography is sensitive and accurate for the determination of the residual chloroform in the medical polylactic acid membrane.
ABSTRACT
OBJECTIVE To observe the effect of natrin from Naja naja atra(Chinese cobra)on intracellular free calcium overload,and to discuss the protective effect and the possible mechanism of natrin on myocardium calcium(Ca2+)and potassium(K+)ion channels in the primary cardiomyocytes of SD neonatal rats. METHODS The primary cardiomyocytes of SD neonatal rats were used,which were respectively pretreated with natrin 5,25 and 125 mg · L-1 for 24 h before injury was induced by H2O2 0.3 mmol · L- 1. The dynamic variation of intracellular calcium was monitored by laser confocal microscopy using Fluo-3 as Ca2+fluorescence probe. Additionally,the cardio myocytes of neonatal rats were pretreated for 24 h using different concentrations of natrin 5,25,125 mg · L-1 and verapamil 5 nmol · L-1,followed by exposure to H2O2 0.3 mmol · L-1 for 15 min. Then,the mRNA expressions of calcium channels subunits Cav1.2,Calm,RyR2 and potassium channel Kir6.2 were analyzed by FQ-PCR method. RESULTS Laser confocal microscopy revealed that H2O2 obviously caused calcium overload in cardiomyocytes, giving rise to 49.37% fluorescence increase in intracellular calcium compared with the control group(P<0.01). However,natrin 5,25 and 125 mg·L-1 resulted in 27.52%, 12.71% and 5.15% fluorescence increase in intracellular calcium,respectively,compared with the control group(P<0.01). Moreover, the PCR results showed that the mRNA expressions of Cav1.2, Calm and RyR2 in the myocardial cells treated with H2O2 were increased 2.78,2.26,and 5.34 times as compared with the control group,while Kir6.2 displayed a 1.79-fold expression level(P<0.01). By contrast, the combination of natrin and verapamil significantly decreased the mRNA expression of Cav1.2,Calm and RyR2,compared to the H2O2-treated group(P<0.01). Meanwhile,the expression of Kir6.2 was considerably higher than that of the H2O2-treated group(P<0.05). CONCLUSION Natrin can reduce the intracellular calcium overload of cardiomyocytes induced by H2O2 and shows a protective effect against oxidative damage for cardiomyocytes. The possible mechanism is that natrin can decrease the mRNA expression of Cav1.2,Calm,RyR2 and increase the expression of Kir6.2 of the H2O2-induced cardiomyocytes.