[Effects of berberine on learning and memory ability in vascular cognitive impairment rats]

To investigate the effects of berberine on learning and memory ability in vascular cognitive impairment rats.

Sixty-eight Wistar rats were randomly divided into control group (n=10), sham operated group (n=10) and the modeling group of vascular cognitive impairment rat (n=48), then the rats in modeling group were randomly divided into four groups (n=10): vehicle group, berberine low dose group (20 mg/kg), medium dose group (40 mg/kg) and high dose group (60 mg/kg). Bilateral common carotid arteries were occluded in rats to establish vascular cognitive impairment (VCI) model. Different doses of berberine were intraperitoneally injected into the treatment group and normal saline was intraperitoneally injected into the other groups once a day for a total of 34 days. After 28 days of administration, Morris water maze was used to test the learning and memory ability of rats. After the water maze experiment, the levels of superoxide dismutase (SOD) activity, glutathione (GSH), malondialdehyde (MDA), tumor necrosis factor alpha(TNF-α), interleukin-1 beta (IL-1β), 5-hydroxytryptamine (5-HT) and monoamine oxidase (MAO) in the forebrain cortex were detected.

Compared to sham group, the escape latency in VCI group was significantly extended (P＜0.01) and the times of passing through the platform were decreased remarkably (P＜0.01). The levels of SOD, GSH and 5-HT in the hippocampus or anterior cortex were decreased significantly (P＜0.01), while the contents of MDA, TNF-α, IL-1β and MAO were increased remarkably (P＜0.01). Compared with VCI group, the escape latency in berberine-treated groups was shortened significantly (P＜0.01, P＜0.05) and the times of passing through the platform were increased remarkably (P＜0.01, P＜0.05), the levels of SOD, GSH and 5-HT were increased significantly (P＜0.01), while the contents of TNF-α, IL-1β and MAO were decreased remarkably (P＜0.01).

Berberine could significantly improve the spatial learning and memory abilities of rats with vascular cognitive impairment. The mechanism may be related to the effects of berberine on the hippocampal antioxidant stress, anti-inflammatory response and the monoamine neurotransmitter system in the forebrain cortex. Berberine 60 mg/kg dose group had better effect.