This study aimed to reveal potential roles of the phosphatidylinositol 3 kinase (PI3K)-protein kinase B (Akt)-mammalian target of rapamycin (mTOR) signaling pathway in apoptosis and autophagy of astrocytes induced by methamphetamine (METH). A Cell Counting Kit-8 (CCK-8) was used to determine the reduction in proliferation of U-118 MG cells induced by METH. Hoechst 33258 and flow cytometry were used to observe the astrocytes. Western blot analysis was performed to evaluate protein expression and phosphorylation levels. METH inhibited the proliferation of U-118 MG cells and induced apoptosis and autophagy. Western blot analysis showed that the ratio of LC3-II/I was increased, whereas the expression of Bcl-2 was decreased. The phosphorylation cascade of kinases in the PI3K-Akt-mTOR signaling pathway was significantly inhibited by METH exposure, as were proteins downstream of mTORC1, such as p70s6k, rps6, 4EBP1 and eIF4E. METH inhibited proliferation of U-118 MG cells and induced apoptosis and autophagy. The PI3K-Akt-mTOR signaling pathway likely plays a critical role in these effects.

In this study we investigated the antineoplastic effects of Berberine (BBR)-mediated photodynamic therapy (PDT) on HeLa cells and its related mechanisms. The CCK-8 assay and flow cytometry were used to evaluate the proliferation and apoptosis of cells respectively. In addition, changes in protein expression levels were assessed using western blot. BBR at dose of 10 mg/kg was injected intraperitoneally to mice with tumors and PDT treatments were performed 24 hours later. In vivo imaging systems were used to evaluate the fluorescence of BBR. In vitro, PDT significantly enhanced the effects of BBR on inducing cell apoptosis and inhibiting proliferation. The in vivo results showed that the fluorescence intensity in the PDT group was decreased compared with that in the BBR group. Tumor weights and tumor size in the PDT group were less than those in the control group; however, when BBR was applied without PDT, no significant differences were observed between the BBR and control group. The results of western blot showed that PDT enhanced the inhibitory effects of BBR on the mammalian target of rapamycin (mTOR) signaling pathway, that may partly explain the potential underlying mechanisms.

Here we show that berberine (BBR) nanoparticles (BBRNPs, ∼300 nm hydrodynamic diameter) is a promising sonosensitizer for cancer sonodynamic therapy (SDT).