Aim: A previous study has shown that physcion 8-O-β-glucopyranoside (PG) derived from Rumex japonicus Houtt causes apoptosis and blocks cell cycle progression in human lung cancer cells. In the present study we investigated the molecular mechanisms underlying PG-induced cancer cell apoptosis. Methods: Human OSCC-derived cell line KB was treated PG (10, 20, 50 µg/mL). Cell apoptosis was detected with flow cytometry. Mitochondrial membrane potential (MMP) and release of cytochome C from mitochondria were measured; the expression of relevant signaling proteins was analyzed using Western blotting or qRT-PCR. For evaluation of in vivo anticancer action, nude mice grafted with KB cells were treated with PG (10, 20, 40 mg·kg -1 ·d -1, ip) for 24 days. Results: PG dose-dependently suppressed cell proliferation and induced apoptosis in KB cells. PG-induced apoptosis was mediated via the intrinsic mitochondrial pathway, as evidenced by the decreased Bcl-2, increased Bax and Bax/Bcl-2 ratio, as well as the loss of MMP, caspase-9 activation, and increased cytosolic cytochrome c. Furthermore, PG suppressed the expression of survivin, whereas overexpression of survivin markedly attenuated PG-induced apoptosis. Meanwhile PG increased the expression of tumor suppressor PTEN, and decreased p-Akt, p-GSK3β and miR-21 levels. Pharmacological activation of Akt/GSK3β signaling or transfection with miR-21 mimic abolished PG-induced survivin reduction and cell apoptosis. Similar results were observed in PG-treated nude mice grafted with KB cells. Conclusion: Physcion 8-O-β-glucopyranoside induces mitochondria-dependent apoptosis of human OSCC cells by suppressing survivin expression via miR-21/PTEN/Akt/GSK3β signaling pathway.

BackgroundDebris extrusion from the apical foramen can be problematic in severely curved canals. This study aimed to assess the use of Twisted Files (TF) at different rotational speeds during retreatment, compared with manual technique using Triple-Flex Files (TFF).MethodsForty-eight mesiobuccal root canals were randomized to four groups (n = 12 per group). In groups A, B, and C, gutta-percha was removed using TF at 500, 1000, and 1500 rpm, respectively, while it was removed using TFF in group D. Apical debris was collected in a pre-weighed centrifuge tube. The weight of dry debris was assessed by comparing the pre- and post-instrumentation weight for each group.ResultsInstrumentation in group D (0.69 ± 0.04 mg) extruded significantly more debris than any of the TF groups (A: 0.54 ± 0.05 mg; B: 0.48 ± 0.04 mg; C: 0.42 ± 0.03 mg; all P < 0.001). In addition, increasing the rotational speed of TF decreased the amount of extruded debris (A vs. B: P = 0.006; B vs. C: P < 0.001; A vs. C: P < 0.001).ConclusionsTF at 1500 rpm produced less apical extrusion debris than other TF operating speeds and TFF.