Protective action of 9-hydroxypinoresinol against oxidative damage in brain of mice challenged with kainic acid

The neuroprotective effect of 9-hydroxypinoresinol was examined in mice challenged with kainic acid (KA), a potent central nervous system excitotoxin. For this purpose, mice were administered intraperitoneally with 9-hydroxypinoresinol before KA injection. A remarkable neuroprotective effect was observed with a single dose of 9-hydroxypinoresinol (30 mg kg(-1)) 24 h before KA challenge. Furthermore, 9-hydroxypinoresinol (20 mg kg(-1)) administered for 3 days before KA challenge reduced the mortality (60%) induced by KA to zero, and alleviated behavioural signs of KA neurotoxicity. Additionally, pretreatment with 9-hydroxypinoresinol (20 mg kg(-1)) prevented the decrease in the levels of total glutathione (GSH) and thiobarbituric acid reactive substances (P < 0.05). GSH peroxidase activity in brain tissue was restored to control levels, although GSH reductase activity and GSH S-transferase activity were not affected. Such a protective action was also observed even with a lower dose (10 mg kg(-1)) of 9-hydroxypinoresinol administered for 3 days, albeit to a lesser extent. From the results, it is proposed that 9-hydroxypinoresinol exerts a potent neuroprotective effect mainly by preventing oxidative stress in brain tissue of mice challenged with KA.