Systematic review of the literature on clinical and experimental trials on the antitumor effects of cannabinoids in gliomas

To evaluate, through a systematic review of the
literature, the antitumoral effects of cannabinoids on gliomas. Research included the following electronic databases:
PUBMED, EMBASE, LILACS and The Cochrane Collaboration Controlled Trials Register. All published studies
involving the antitumoral effects (cellular and molecular
mechanisms) of cannabinoids were considered for this
review. The bibliography search strategy included all publications of each of these databases until December 31, 2012.
From 2,260 initially identified articles, 35 fulfilled the
inclusion criteria for this review. All the studies included in
this systematic review were experimental (in vivo and/or
in vitro), except for one pilot clinical trial phase I/II
involving humans. In all experimental studies included,
cannabinoids exerted antitumoral activity in vitro and/or
antitumoral evidence in vivo in several models of tumor cells
and tumors. The antitumor activity included: antiproliferative effects (cell cycle arrest), decreased viability and cell
death by toxicity, apoptosis, necrosis, autophagy, as well as
antiangiogenic and antimigratory effects. Antitumoral evidence included: reduction in tumor size, antiangiogenic, and
antimetastatic effects. Additionally, most of the studies
described that the canabinnoids exercised selective antitumoral action in several distinct tumor models. Thereby,
normal cells used as controls were not affected. The safety
factor in the cannabinoids’ administration has also been
demonstrated in vivo. The various cannabinoids tested in
multiple tumor models showed antitumoral effects both
in vitro and in vivo. These findings indicate that cannabinoids are promising compounds for the treatment of gliomas