Moreover, both the ethanol extracts of Radix Polygalae and onjisaponin B derived from those extracts may play a protective role in neurodegenerative diseases by accelerating the removal of overexpressed mutant proteins such as A53T α-synuclein and huntingtin with 74 CAG repeats, as well as by reducing α-synuclein oligomerization in cells. Here, HTT is linked to neurodegenerative disease.