Radioprotective role of clinical drug diclofenac sodium

We have shown radioprotective potential of NSAID category of drug diclofenac sodium and it has shown a survival of 45.5% in mice upon lethal irradiation of 9Gy. •Clonogenic survival in Chinese hamster V79 cells shows a dose modification factor (DMF) of 1.4.•Radioprotection by sodium diclofenac in plasmid pBR322 DNA.•ABTS assay shows diclofenac to be a free radical scavenger which follows electron donation mode.•Whole body animal survival study in C57BL/6 mice shows 45.5% survival at lethal radiation dose of 9Gy. The potential of clinical drug diclofenac sodium which is routinely used in clinics as non-steroid anti-inflammatory drugs opens a new insight in development of radioprotector. The drug has shown its potential radioprotective efficacy in clonogenic cell survival in Chinese hamster V79 cells with a DMF of 1.4. The pBR322 plasmid DNA gets damaged by radiation in which the supercoiled form gradually disappears with increasing radiation dose. Diclofenac sodium has shown its radioprotective potential by scavenging radiation induced free radicals which are depicted by its ability in restoring the fraction of supercoiled form of plasmid DNA back to normal. 250μM concentration of the drug provides GSSB yield of 3.65±0.5×10−9Da−1Gy−1. This drug has shown to have a free radical scavenging activity because the radical cation with blue color is converted to the colorless neutral form by addition of diclofenac sodium in ABTS assay. Whole body survival study has shown it to protect 45.5% of C57BL/6 mice at a lethal irradiation dose of 9Gy. Therefore, this molecule offers a potential radioprotective ability besides being used routinely as analgesic and anti inflammatory compound.