Effects of Chinese herbal medicine Xifeng Capsule on multidrug resistance-associated protein 1 expression in hippocampus and cortex of rats with lithium-pilocarpine-induced epilepsy

Abstract

To study the effects of Xifeng Capsule, a compound traditional Chinese herbal medicine, combined with carbamazepine on spontaneous epileptic seizure induced by lithium and pilocarpine in rats and the expression level of multidrug resistance-associated protein 1 (MRP1). Lithium and pilocarpine were used to induce epilepsies in rats. All epileptic rats were randomly divided into model, high-dose Xifeng Capsule, medium-dose Xifeng Capsule, low-dose Xifeng Capsule, high-dose Xifeng Capsule plus carbamazepine (CBZ) (combined high-dose group), high-dose Xifeng Capsule plus half dose of CBZ (combined low-dose group) and CBZ groups with 10 rats in each group. And another 10 normal rats served as control. After treating 28 d, immunohistochemical method was used to detect the MRP1 expression in cortex and hippocampus of the epileptic rats. MRP1 expression in hippocampus of the treated groups was higher than that of the normal control group, with wider range and darker positive particles, but was lower than that of the model group. In the cortical areas, the differences between the combined high-dose group or the combined low-dose group and the model group were statistically significant (P<0.05). Regardless of the hippocampus CA1, CA3, gyrus or cortical areas, the influence of high-dose Xifeng Capsule on MRP1 distribution was superior to that of low-dose Xifeng Capsule; Xifeng Capsule combined with CBZ had better effects than low-dose Xifeng Capsule, medium-dose Xifeng Capsule and CBZ used alone (P<0.05). Xifeng Capsule used alone or combined with CBZ can effectively inhibit MRP1 expression in hippocampus and cortex of epileptic rats.