Psorinum 6 × triggers apoptosis signals in human lung cancer cells / 中西医结合学报

<p><b>OBJECTIVE</b>To provide in vitro evidence of Psorinum treatment against cancer cells in a controlled study.</p><p><b>METHODS</b>Effects of homeopathic Psorinum 6× on cell viability were initially determined in several cancer cell lines, including A549, HepG2 and MCF-7, using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and an ethanol 6× control. The cell line that exhibited highest inhibition was selected and used in the following experiments. A range of Psorinum 6× doses was used to explore treatment effects on cell cycle arrest, cell death (apoptosis), generation of reactive oxygen species (ROS) and change in mitochondrial membrane potential (MMP) using flow cytometry and fluorescence microscopy, respectively. Expression of several signal proteins related to apoptosis and cell survival were quantified with Western blotting and confocal microscopy. Further, circular dichroism (CD) spectroscopy was used to determine possible drug-DNA interactions, as well as the induction of conformational changes.</p><p><b>RESULTS</b>Treatment of cancer cell lines with Psorinum showed greater anticancer effects in A549 cells than in others. In A549 cells Psorinum treatment inhibited cell proliferation at 24 h after treatment, and arrested cell cycle at sub-G1 stage. It also induced ROS generation, MMP depolarization, morphological changes and DNA damage, as well as externalization of phosphatidyl serine. Further, increases in p53 expression, Bax expression, cytochrome c release, along with reduction of Bcl-2 level and caspase-3 activation were observed after Psorinum 6× treatment, which eventually drove A549 cells towards the mitochondria-mediated caspase-3-dependent pathway. CD spectroscopy revealed direct interaction of Psorinum with DNA, using calf thymus-DNA as target.</p><p><b>CONCLUSION</b>Psorinum 6× triggered apoptosis in A549 cells via both up- and down-regulations of relevant signal proteins, including p53, caspase-3, Bax and Bcl-2.</p>

Diarylheptanoid-myricanone isolated from ethanolic extract of Myrica cerifera shows anticancer effects on HeLa and PC3 cell lines: signalling pathway and drug-DNA interaction / 中西医结合学报

<p><b>OBJECTIVE</b>To test if myricanone (C21H24O5), a cyclic diarylheptanoid, has anticancer effects on two different cancer cell lines HeLa and PC3. The present study was conducted with a note on the drug-DNA interaction and apoptotic signalling pathway.</p><p><b>METHODS</b>Several studies like cytotoxicity, nuclear damage, annexin-V-fluorescein isothiocyanate (FITC)/propidium iodide (PI)-labelled apoptotic assay and cell cycle arrest, immunoblot and reverse transcriptase-polymerase chain reaction (RT-PCR) were used following standard protocols. Circular dichroism (CD) spectroscopy was also done to evaluate whether myricanone effectively interacted with DNA to bring about conformational changes that could strongly inhibit the cancer cell proliferation.</p><p><b>RESULTS</b>Myricanone showed a greater cytotoxic effect on PC3 cells than on HeLa cells. Myricanone promoted G0/G1 arrest in HeLa cells and S phase arrest in PC3 cells. Nuclear condensation and annexin V-FITC/PI studies revealed that myricanone promoted apoptotic cell death. CD spectroscopic data indicated that myricanone had an interaction with calf thymus DNA that changed DNA structural conformation. RT-PCR and immunoblot studies revealed that myricanone activated the apoptotic signalling cascades through down-regulation of transcription factors like nuclear factor-κB (NF-κB) (p65), and signal transducers and activators of transcription 3 (STAT3); cell cycle regulators like cyclin D1, and survivin and other signal proteins like Bcl-2 and up-regulation of Bax, caspase-9 and caspase-3.</p><p><b>CONCLUSION</b>Myricanone induced apoptosis in both types of cancer cells by triggering caspase activation, and suppression of cell proliferation by down-regulation of NF-κB and STAT3 signalling cascades, which makes it a suitable candidate for possible use in the formulation of therapeutic agent for combating cancer.</p>