[Dihydroartemisinin Induces AML cell Apoptosis by Inhibition of PTEN/AKT pathway].

OBJECTIVE: To study the effects of dihydroartemisinin (DHA) on the proliferation and apoptosis of acute myeloid leukemia (AML) cells. METHODS: The effects of DHA on the proliferation of acute myeloid leukemia cells and the inhibitory effect of Z-VAD-FMK on the DHA-induced cell apoptosis were detected by CCK-8 assay. The expression level of cleaved-caspased 3 was detected by indirect immunofluorescence. Western blot was used to quantify the protein expression of PTEN, p-Akt, AKT, ß-actin, and the apoptosis-associated proteins, such as C-PARP, Cleaved-caspase3 and Caspase3 respectively. RESULTS: DHA induced the AML cell apoptosis with concentration-dependent manner (rKasumi-1=-0.959, rKG-1=-0.956). The DHA could induce the accumulation of cleaved-caspase 3 and C-PARP in AML cells, activate PTEN gene and inhibited Akt phosphorylation. Apoptosis inhibitor Z-VAD-FMK could partially restored the activity of DHA-inhibited cell proliferation. CONCLUSION: Dihydroartemisinin induces AML cell apoptosis by inhibition of PTEN/AKT pathway. Dihydroartemisinin is expected to be a safe and effective drug for treatment of acute myeloid leukemia.

The protective effect of picroside II against hypoxia/reoxygenation injury in neonatal rat cardiomyocytes.

CONTEXT: Picroside II, an iridoid glucoside found in the root of Picrorhiza scrophulariiflora Pennell (Scrophulariaceae), has been demonstrated to possess potent antioxidant activity. However, whether picroside II has a protective effect against hypoxia/reoxygenation (H/R)-induced cardiomyocyte injury is poorly understood. OBJECTIVE: To explore the cardioprotective role of picroside II against oxidative stress induced by H/R injury in neonatal rat cardiacmyocytes. MATERIALS AND METHODS: The viability and cellular damage of cardiomyocytes were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolim bromide (MTT) and lactate dehydrogenase (LDH) assays, respectively. The activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), the levels of reduced (GSH) and oxidized glutathione (GSSG), and the contents of malondialdehyde (MDA) were determined by a colorimetric method. The levels of intracellular reactive oxygen species (ROS) and calcium were evaluated by flow cytometric analysis. RESULTS: We analyzed the effective half-maximal concentration for protection from the dose-response curves and obtained the concentration of 50 µg/mL as EC(50). Pretreated cardiomyocytes with picroside II (50-200 µg/mL), prior to H/R exposure, inhibited LDH activity in culture media and increased cell viability in a dose-dependent manner. This protective effect was accompanied by significantly increasing reduced GSH contents and the activities of SOD and GSH-Px and attenuating MDA and GSSG contents in response to H/R injury. Furthermore, treatment with picroside II also inhibited ROS production and calcium accumulation in cardiomyocytes. DISCUSSION AND CONCLUSION: The present study demonstrates that picroside II protects cardiomyocytes against oxidative-stress injury induced by H/R through reduction of ROS production and calcium accumulation and enhancement of the activity of antioxidant defense.