Globularifolin exerts anticancer effects on glioma U87 cells through inhibition of Akt/mTOR and MEK/ERK signaling pathways in vitro and inhibits tumor growth in vivo.

Gliomas are the most recurrently occurring primary malignancies in the central nervous system. Despite surgical interventions, chemo- and radiotherapy, the results are unfortunately poor. Therefore, there is pressing need to explore more effective and efficient treatment options for treatment of glioma. In the present study we determined the anticancer potential of globularifolin against human glioma U87 cell line and human astrocytes. The results showed that globularifolin exhibits an IC50 value of 7.5 μM against glioma U87 cells as against the IC50 of 65 μM against human astrocytes. The molecule exerted its anticancer activity through induction of apoptosis as evident from the Bid-, and Bax controlled cytochrome c and Omi/HtrA2 release, XIAP suppression, and caspase-9 and 3 signalling cascade. Additionally, it also caused cell cycle arrest of human glioma U87 cancer cells in the S phase of the cell cycle. Interestingly, globularifolin also caused significant inhibition of Akt/mTOR/p70S6K and MEK/ERK pathways. Globularifolin also inhibits cell migration and invasion by regulating the expression of matrix metalloproteinases (MMPs) in U87 glioma cells. We further investigated whether globularifolin exhibits the same effectiveness against glioma cell xenografts in nude mice in vivo and it was observed that globularifolin significantly reduced the tumor growth and volume in vivo indicating the potential of globularifolin as lead molecule for glioma chemotherapy.