Neuroprotective effects of salvianolic acid B on an Aβ25–35 peptide-induced mouse model of Alzheimer's disease

Salvianolic acid B (SalB) is a polyphenolic compound found in Salvia miltiorrhiza Bunge that has several anti-oxidative and anti-inflammatory effects. In the present study, we investigated whether SalB has neuroprotective effects in an amyloid β (Aβ) peptide-induced Alzheimer's disease mouse model. Mice were injected with Aβ25–35 peptide intracerebroventricularly and were subsequently administered SalB once daily for 7 days. Subchronic SalB administration (10 mg/kg) significantly ameliorated the Aβ25–35 peptide-induced memory impairment in the passive avoidance task (P<0.05). SalB treatment also reduced the number of activated microglia and astrocytes that were observed during the inflammatory reaction after the administration of the Aβ25–35 peptide. Moreover, SalB markedly reduced inducible nitric oxide synthase and cyclooxygenase-2 expression levels and thiobarbituric acid reactive substances, which were increased by the administration of the Aβ25–35 peptide. Furthermore, SalB administration significantly rescued the Aβ25–35 peptide-induced decrease of choline acetyltransferase and brain-derived neurotrophic factor protein levels. These results suggest that SalB exerts neuroprotective activity via anti-inflammatory and anti-oxidative effects and that SalB may be a potential candidate for Alzheimer's disease therapy.