Tricin 7-glucoside protects against experimental cerebral ischemia by reduction of NF-κB and HMGB1 expression

There have been several studies of nuclear factor-κB (NF-κB) and high-mobility group box1 (HMGB1) associated with the pathophysiology of cerebral ischemia. Tricin 7-glucoside, a major bioactive compound extracted from Sedum sarmentosum Bunge. The objectives of this study were to determine the effects of Tricin 7-glucoside on a cultured neuronal cell line, SH-SY5Y in vitro and experimental ischemic stroke in vivo. For oxygen-glucose deprivation (OGD) and tumor necrosis factor-α (TNF-α) stimulated SH-SY5Y cell line in vitro, SH-SY5Y cells were incubated with Tricin 7-glucoside. For in vivo experiment, rats were subjected to middle cerebral artery occlusion (MACO) for 1h, then followed by reperfusion for 23 h. Treatment of SH-SY5Y cells with Tricin 7-glucoside reduced the OGD-induced apoptosis and cytotoxicity, blocked TNF-α-induced NF-κB and IκB-α phosphorylation, and decreased HMGB1 expression. At doses higher than 50mg/kg, Tricin 7-glucoside produced a significant neuroprotective potential in rats with ischemia and reperfusion (I/R). Tricin 7-glucoside (100mg/kg) demonstrated significant neuroprotective activity even after delayed administration at 2h and 4h after I/R. Tricin 7-glucoside 100mg/kg attenuated histopathological damage, decreased brain edema, inhibited NF-κB activation and reduced HMGB1 expression. These data show that Tricin 7-glucoside protects brain against I/R injury with a favorable therapeutic time-window by alleviating cerebral I/R injury and attenuating blood-brain barrier (BBB) breakdown, and its protective effects may involve HMGB1 and NF-κB signaling pathway.