A method for treating a subject suffering from a neurodegenerative disease includes administering at least one triterpenoid which can be obtained from Hedera helix. A method for treating a subject suffering from a neurodegenerative disease includes administering an effective amount of a Hedera helix extract which comprises the triterpenoid. The neurodegenerative disease is preferably but not exclusively Parkinson's disease or Huntington's disease. Methods for extracting the triterpenoid from Hedera helix and a method for inducing autophagy in cells by contacting them with the triterpenoid are also provided. The triterpenoid allows an exceptional induction of autophagy, in particular a significant reduction of the protein level of mutant huntingtin, a significant reduction of the protein level of A53T α-synuclein, a significant inhibition of the oligomerization of α-synuclein and a significant inhibition of the inclusion formation of huntingtin via the AMPK-mTOR dependent autophagy inducing pathway.
