In Vitro Antitumoral Effect of Tarantula Venom Combined with Temozolomide in Human Glioblastoma Cells

To investigate the effect of 48-hour (h) administration of Tarantula Logoplex® (TL), a homeopathic medical product containing Tarantula cubensis venom, alone and in combination with temozolomide (TMZ) on T98G glioblastoma cell line with regard to cytotoxicity, cell migration, nitric oxide synthase (NOS) level, and the type of programmed cell death pathway that mediates this cytotoxic effect.

Cytotoxic effect was analyzed using the 3-(4,5-dimethylthiazolyl-2)-2.5-diphenyltetrazolium bromide (MTT) method, apoptosis was analyzed by Annexin V-FITC/PI flow cytometry, autophagic cell imaging was performed using the monodansylcadaverine staining method, mitochondrial membrane potential was evaluated using the tetraethylbenzimidazolylcarbocyanine iodide (JC-1) staining method, and cell migration was analyzed using the scratch test. The levels of eNOS, iNOS, and LC3 proteins were evaluated using immunofluorescence (IF) and western blot analyses. Results were compared and statistically evaluated.

Annexin V-FITC/PI flow cytometry revealed that the cytotoxicity of the combined administration was high and primarily (37.57%) occurred through apoptosis. According to JC-1 analysis, the apoptotic effect could have originated from mitochondria. Cell migration was lowest at the IC 50 dose of TL. The order of fluorescence intensity from the strongest to the weakest was control > TL > combination > TMZ for eNOS and control TL combination > TMZ for iNOS. Western blotting revealed the highest eNOS and iNOS protein density with TL IC 25 administration and the highest LC3 protein density with TMZ IC 50 administration.

Combined administration of TL and TMZ may exert a significant cytotoxic effect on T98G glioblastoma cells, which may occur through apoptosis. TL may play a role in augmenting the effect of conventional therapeutic drugs on glioblastoma.