Meisoindigo inhibits cellular proliferation via down-regulation of the PI3K/Akt pathway and induces cellular apoptosis in glioblastoma U87 cells

Objective: The current study was to explore whether meisoindigo was effective in suppressing proliferation and inducing apoptosis of human glioblastoma multiforme U87 cells and to explore its possible mechanisms. Method: Morphological changes were observed by light microscopy. Cell counting kit-8 (CCK-8) assay was performed to detect cellular proliferation. Apoptosis was monitored by flow cytometry. Akt, phospho-Akt, PI3K, p65, phospho-p65 and apoptosis-related proteins caspase-3 and caspase-9 were examined by Western blotting assays. Immunofluorescence was used to evaluate level of P65 expression in cells. Result: Meisoindigo inhibited the proliferation of U87 cells, and the inhibitory effect increased in a dose dependent manner. Moreover, meisoindigo exposure triggered an increase in the level of caspase-3 and caspase-9, supporting its role in the activation of apoptosis. Furthermore, meisoindigo reduced the expression of PI3K, Akt, phospho-Akt, NF-κB, p65 and phospho-p65 in U87 cells, and displacement of p65 from the nucleus to the cytoplasm. Conclusion: Meisoindigo inhibits proliferation and induces apoptosis of U87 cells, probably through down-regulating the PI3K/Akt pathway and reducing nuclear translocation of NF-κB p65.