Iranian Scorpion (Odontobuthus bidentatus) Venom Induces Apoptosis in the Hepatocellular Carcinoma Cell Line (HepG2) in 3D Cell Culture

AbstractBackground:Scorpion venom has anticancer properties and induces apoptosis in mammalian cells considered as an anticancer agent. Generally, the 3D cell models characteristically and architecturally mimicked by the natural tumors, which are a suitable system for investigating cytotoxic and apoptotic induction effects of scorpion venom on cancer cells. In this study, the cytotoxicity and apoptotic induction effects ofOdontobuthus bidentatusscorpion venom on HepG2 cells in 3D cell culture investigated.Methods and Results:To create a 3D cell culture, HepG2 cells encapsulated using alginate hydrogel. Then, the cytotoxicity effect of scorpion venom investigated using MTT and neutral red uptake assays. Changes in the redox potential of HepG2 cells evaluated by determination of accumulated NO in cell culture media, glutathione (GSH) levels, and catalase activity. To determine apoptosis induction in the cells treated with scorpion venom, alkaline comet, caspase-3 enzyme activity and cytochrome c release assays exploited and the expression of pro-apoptotic geneBAXand anti-apoptotic geneBCL-2 evaluated using RT-PCR. The results of MTT and neutral red uptake assays showed thatO. bidentatusvenom has cytotoxic effects on HepG2 cells in 3D cell culture. The concentration of NO released to culture media was increased, but the amount of reduced glutathione and catalase were decreased dose-dependently in 3D culture. The results of caspase-3 enzyme activity, cytochrome c release assay, comet assay, andBax/Bcl-2genes expression ratio confirmed that theO. bidentatusscorpion venom induces apoptosis through the mitochondrial pathway.Conclusions:Overall, the results showed that the scorpion venom induce apoptosis in HepG2 cells in 3D culture and thus could be a potential therapeutic option for further research in the treatment of HCC.