BiliarY obstruction was performed in male Wistar albino rats by bile duct ligation and scission (BDL). Intragastric NS oil (1 mg/kg p.o.) or saline was administered for 28 days. At the end of the experiment, in the half of the rats the blood brain barrier (BBB) permeability was evaluated by Evans blue (EB) extravasation. Other rats were decapitated and brain tissue samples were obtained for the measurement of malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) and Na⁺,K⁺-ATPase activities.

ChronIC biliary obstruction caused a significant increase in the BBB permeability which was verified by EB extravasation while this effect was attenuated by NS oil treatment. On the other hand, BDL-induced decrease in brain GSH level and Na⁺,K⁺-ATPase activity were elevated back to control level in NS oil-treated BDL group. Increase in tissue MDA level, and MPO activity due to BDL were also attenuated by NS oil treatment.

Our results suggest that NS oil treatment protects the brain from oxidative damage following bile duct ligation in rats. This effect possibly involves the inhibition of neutrophil infiltration and lipid peroxidation and the restoration of antioxidant status in the tissue. Accordingly, supplementing cirrhotic patients with adjuvant therapy of NS oil may have some benefit against hepatic encephalopathy. Keywords : Nigella, black cumin, bile duct, brain, edema