Troxerutin, a plant flavonoid, protects cells against oxidative stress-induced cell death through radical scavenging mechanism

Troxerutin (TRX) is a flavonoid present in tea, coffee, cereal grains, various fruits and vegetables have been reported to exhibit radioprotective, antithrombotic, nephro and hepato-protective effects. A systematic study was undertaken to evaluate its free radical scavenging ability and anti-apoptotic activity in cell-free and cellular systems. TRX scavenged superoxide, nitric oxide and also other model stable radicals like 1,1-diphenyl-2-picryl-hydazyl, and 2,2′-azinobis3-ethylbenzothiazoline-6-sulfonic acid. It reacted with hydroxyl radicals, carbonate and thiocyanate anions, as evaluated by pulse radiolysis and stopped flow techniques. TRX protected different cell types (epithelial cells, fibroblasts and lymphocytes) against peroxyl radical-induced apoptosis, necrosis and mitotic death. It scavenged intracellular basal and inducible ROS levels and also restored depletion of intracellular GSH levels, suggesting that free radical scavenging ability may be responsible for the observed cytoprotection of different cell types. TRX may find application as an adjuvant in treating various diseases attributed to oxidative stress.