Tetrandrine, a
bisbenzylisoquinoline alkaloid, has antitumor effects against some
cancers, but its effects on
gliomas are unknown. In this study, we investigated the effects of
tetrandrine on the growth and angiogenesis of rat RT-2
gliomas. We treated RT-2
glioma cells with
tetrandrine and then measured cytotoxicity, apoptosis and expression of
vascular endothelial growth factor (
VEGF). We also examined the cytotoxic effect of
tetrandrine on the ECV304 human umbilical vein endothelial cells and the effects of
tetrandrine on the in vivo angiogenesis.
Tumor size and animal survival were followed in
tetrandrine-treated rats with subcutaneous or intracerebral
gliomas. Expression of CD31 in
tetrandrine-treated
gliomas was followed to study its effect on
glioma-induced angiogenesis.
Tetrandrine had cytotoxic effects and induced apoptosis of
glioma cells in a concentration- and time-dependent manner.
Tetrandrine also inhibited the expression of
VEGF in
glioma cells, induced cytotoxicity effect on the ECV304 cells and suppressed the in vivo angiogenesis.
Tetrandrine (150 mg/kg/day) had significant antitumor effects on subcutaneous
tumors and led to slower
tumor growth rate, longer animal survival time and higher animal survival (p < 0.05).
Tetrandrine also affected intracerebral
tumors and prolonged animal survival (p < 0.05) without affecting survival rate. Immunohistochemical analyses showed that the subcutaneous
gliomas from
tetrandrine-treated rats had fewer microvessel densities than control rats (p = 0.01). The results demonstrate that
tetrandrine is cytotoxic to RT-2
glioma cells, has antitumor effects on subcutaneous and intracerebral
gliomas, and inhibits angiogenesis in subcutaneous
gliomas.
Tetrandrine has potential as a treatment for
gliomas.