Effects of puerarin on cholinergic enzymes in the brain of ovariectomized guinea pigs

Abstract

Estrogen has beneficial effects on neurodegenerative disorders and cognitive function of postmenopausal women. Puerarin, isolated from Pueraria lobota, has been classified as a phytoestrogen, which can be highly effective against cerebrovascular diseases. In this study, the effects of puerarin on neural cholinergic system in the brain of ovariectomized guinea pigs were studied. The puerarin at the doses used (15 mg/kg body weight (bw)/day and 30 mg/kg bw/day) for 10 days had the estrogenic activity indicated by the attenuation of the reduction of uterine weight induced by ovariectomy. In brain, puerarin treatment increased choline acetyltransferase (ChAT) activity and expression in hippocampus, and increased ChAT immnuopositive signals in septal diagonal region. Puerarin treatment could suppress the increase of acetylcholinesterase expression and activity to the levels of the intact group, although they were not significantly different from those of the ovariectomized animals. Moreover, puerarin decreased the β-amyloid immunopositive staining in hippocampus. In brief, the present study suggests that puerarin prevents the dysfunction of the neuronal cholinergic system and ameliorates the increase of β-amyloid caused by estrogen deficiency.

KEYWORDS: :

• Puerarin
• ovariectomy
• guinea pig
• choline acetyltransferase
• acetylcholinesterase
• β-amyloid