Protective effects of Huang-Lian-Jie-Du-Tang against Aβ(25–35)-induced memory deficits and oxidative stress in rats

OBJECTIVE: Huang-Lian-Jie-Du-Tang (HLJDT), a traditional Chinese medicine, improves cognitive ability in rat models of Alzheimer’s disease (AD). The objective of this study was to evaluate the protective effects of HLJDT on learning and memory impairment that are caused by Aβ(25–35). METHODS: Rats were randomly assigned to the following groups: control (water), Aβ(25–35), donepezil hydrochloride 1.05 mg/kg, HLJDT 6 g/kg, HLJDT 3 g/kg, and HLJDT 1.5 g/kg and the corresponding drugs were administered for 28 days by oral gavage. HLJDT for the prevention of Aβ(25–35)-induced injury in rats and the underlying mechanisms were assessed. Aβ(25–35) and amyloid precursor protein (APP) levels were measured in the hippocampal specimens. Total superoxide dismutase (T-SOD), glutathione (GSH), and malondialdehyde (MDA) levels in the hippocampus were also measured. The ultrastructure of CA1 hippocampal region was observed using electron microscopy. RESULTS: HLJDT treatment ameliorated impaired learning and memory significantly, decreased Aβ(25–35), and APP levels in the hippocampus, increased T-SOD and GSH activity and decreased the MDA concentration, and alleviated the nuclear and cytoplasmic abnormalities of the hippocampal CA 1 region that were induced by Aβ(25–35) injection. CONCLUSIONS: HLJDT might decrease hippocampal vulnerability to Aβ(25–35), suggesting its potential neuroprotective effect in AD.