Amyloid β (Aβ) induced microglial activation and attendant
neuroinflammation play pivotal roles in
Alzheimer's disease (AD) pathogenesis.
Matrine is a natural anti-
inflammation compound from the Chinese herbal medicine Sophora flavescens Ait. (
Kushen). This study aimed to investigate the effects of
matrine on
memory deficit and
neuroinflammation in an oligomeric Aβ (oAβ)-induced AD mice model. Whether microglial activation and
NADPH oxidase were involved in these effects were further studied. Different doses of
matrine (10, 20, or 40 mg/kg) were intragastrically administered once a day after intracerebroventricular oAβ injection (2.5 μg/μl, 4 μl). 15 days after the oAβ injection, behavioral experiments including novel object recognition (NOR) test and Morris water maze (MWM) test were performed. 21 days after the oAβ injection, concentration of ROS, TNF-α, IL-1β and
IL-6 as well as expression of
NADPH oxidase subunits gp91phox and p47phox in mice hippocampal tissues were assessed, and microglial activation were evaluated by Iba-1 immunohistochemical staining. Results of NOR test and MWM test revealed that oAβ injection could remarkably impair learning and memory function in AD mice, and
matrine administration could significantly ameliorate the impairment. ROS, TNF-α, IL-1β and
IL-6 levels increased after oAβ injection, while
matrine could significantly reduce the concentrations of these inflammatory factors. OAβ induced
protein expression of
NADPH oxidase subunits gp91phox and p47phox were also significantly reduced by
matrine. Iba-1 immunohistochemistry results showed less activated microglia in
matrine-treated mice brain. These results indicate that
matrine could ameliorate learning and memory impairment and
neuroinflammation induced by oAβ injection. These effects were found to be mediated through inhibition of microglial activation and
NADPH oxidase expression in hippocampal tissue. The results suggest that
matrine may be a valuable natural compound with therapeutic potential against AD.