Combination of tenuigenin-based Polygala tenuifolia willd. root extract and forsythoside a improved Alzheimer's disease

Tenuigenin is a kind of the main active ingredients in roots of Polygala tenuifolia Willd. (a species in the genus Polygala, family Polygalaceae) and forsythoside A (FA) is one of the main active ingredients of Forsythia suspensa (Thunb.) Vahl. (a species in the genus Forsythia, family Meliaceae). The studies have shown that tenuigenin-based Polygala tenuifolia Willd. extract (YZ) and FA have protective effects on nervous damage. In the study the combination (YF) of YZ and FA showed synergistic neuro-protective effects on PC12 cell model of Alzheimer's disease (AD). YF (2:1) which was made up of 2/3 YZ and 1/3 FA increased cell viability, inhibited AChE expression and activity, alleviated apoptosis and slowed Aβ aggregation, while YF (1:2) which consisted of 1/3 YZ and 2/3 FA depressed inflammation and oxidative stress. There was no obvious synergistic effect of YF on Tau phosphorylation.