Abstract: Objective To investigate the effect of minocycline on the cognition and expressions of brain- derived neurotrophic factor (BDNF), apoptosis related factor Bcl-2 and Bax in hippocampus of rats with Alzheimer’ s disease (AD).Methods The rat model was established by microinjection of Aβ25-35 into lateral ventricle. Thirty healthy male SD rats were randomly divided into three groups: control group, model group and minocycline treatment group. Normal saline 1 mL/(kg· d) was intraperitoneally injected in control group and model group. The minocycline treatment group was intraperitoneally injected with minocycline 50 mg/(kg· d) for 14 days. Morris water maze was used to detect the behaviors of animals. The expressions of BDNF, Bcl-2 and Bax in hippocampus were measured by Western blotting and enzyme linked immunosorbent assay (ELISA). The apoptosis of neurons was detected by TdT- mediated dUTP nick- end labeling (TUNEL). Results Minocycline greatly improved the behaviors of AD rats, up- regulated the expressions of BDNF and Bcl- 2, and downregulated the expression of Bax in hippocampus, and reduced cell apoptosis. Conclusion Minocycline plays a protective role in neural function by promoting the growth of neurons and inhibiting the neuronal apoptosis.

Key words: Tetracyclines, Alzheimer disease, apoptosis, nerve tissue proteins, cognition, Minocycline, brain-derived neurotrophic factor