Silibinin (Silybin) as an active constituent derived from milk thistle (Silybum marianum) has been shown to have antioxidant and anti-apoptotic properties. In traditional system of medicine, Silybum marianum has been used for treating various kinds of ailments including liver disease and cancer; however, clinical studies are largely heterogeneous and contradictory. The present study was designed to investigate whether Silibinin protects neuronal injury against middle cerebral artery occlusion induced oxidative stress associated damages in focal cerebral ischemia in Wistar rats. Rats weighing 250 to 300 g were pretreated with Silibinin 100 mg/kg and 200 mg/kg body weight, suspended in 0.5% of gum acacia) once daily for seven days. On 8th day, they underwent for middle cerebral artery 2 h suture occlusion by nylon suture. After 120 min of middle cerebral artery occlusion (MCAO) and 22 h of reperfusion, behavioral tests were assessed in terms of neurological deficits. Animals were sacrificed and infarct volume in Triphenyltetrazolium chloride (TTC) stained brain sections was measured. Further, various oxidative biomarkers were estimated in brain homogenates of rats. Pretreatment with Silibinin at doses of 100 and 200 mg/kg significantly improved the neurobehavioural alterations and reduced the infarct volume whereas 200 mg/kg Silibinin significantly increases the Glutathione (GSH) level and the others parameters with respect to control values. These results clearly indicate the neuroprotective effect of Silibinin against middle cerebral artery occlusion associated with oxidative damage induced brain injury due to its antioxidant and anti-apoptotic property.
Key words: Neuroprotective, MCAO, Silibinin, oxidative stress, infarct volume, cerebral ischemia.