Tarantula cubensis venom (Theranekron) selectively destroys human cancer cells via activating caspase-3-mediated apoptosis
Background: Tarantula cubensis venom (Theranekron®) is used as a homeopathic medicine which has shown anti-tumor effects in veterinary medicine. The aim of this study was to assess effect of Tarantula cubensis venom on apoptotic cell death of human cancer cell lines. Methods: HEK293, MCF7 and HN5 cell lines were used. The cells were treated with different concentrations of alcoholic extract of Tarantula cubensis (Theranekron®) for different periods of time. Cell morphology was studied by light microscopic observation. Cell proliferation was evaluated by MTT assay and death rate was assessed applying trypan blue staining. Apoptosis was assessed by DNA fragmentation, cleaved caspase-3 protein western blotting and ELISA caspase-3 activity assays. Results: Tarantula cubensis venom ruined cell adhesion, reduced cell proliferation, increased cell death rates and caused DNA fragmentation in human cells. An increased caspase-3 cleavage and hyper-activation of caspase-3 was detected in the cells treated with the venom. Results also showed a significantly higher toxicity and apoptosis levels in cancer cell lines MCF7 and HN5 compared with non-cancerous HEK293 cells. Conclusion: We conclude that Tarantula cubensis venom is selectively toxic for human cancer cells via inducing caspase-3- mediated apoptosis.