Irradiated riboflavin over nonradiated one: Potent antimigratory, antiproliferative and cytotoxic effects on glioblastoma cells.

Riboflavin is a water-soluble yellowish vitamin and is controversial regarding its effect on tumour cells. Riboflavin is a powerful photosensitizer that upon exposure to radiation, undergoes an intersystem conversion with molecular oxygen, leading to the production of ROS. In the current study, we sought to ascertain the impact of irradiated riboflavin on C6 glioblastoma cells regarding proliferation, cell death, oxidative stress and migration. First, we compared the proliferative behaviour of cells following nonradiated and radiated riboflavin. Next, we performed apoptotic assays including Annexin V and caspase 3, 7 and 9 assays. Then we checked on oxidative stress and status by flow cytometry and ELISA kits. Finally, we examined inflammatory change and levels of MMP2 and SIRT1 proteins. We caught a clear antiproliferative and cytotoxic effect of irradiated riboflavin compared to nonradiated one. Therefore, we proceeded with our experiments using radiated riboflavin. In all apoptotic assays, we observed a dose-dependent increase. Additionally, the levels of oxidants were found to increase, while antioxidant levels decreased following riboflavin treatment. In the inflammation analysis, we observed elevated levels of both pro-inflammatory and anti-inflammatory cytokines. Additionally, after treatment, we observed reduced levels of MMP2 and SIRT. In conclusion, radiated riboflavin clearly demonstrates superior antiproliferative and apoptotic effects on C6 cells at lower doses compared to nonradiated riboflavin.