A method for providing neuroprotection to a patient in need of neuroprotection, comprising administering a neuroprotective-effective amount of a compound of formula I in which X is an oxygen atom or an ═N—OH group, R is selected from the group consisting of A is a hydrogen atom or together with B a carbon-carbon bond, B is a hydrogen atom, a hydroxy group or together with A a carbon-carbon bond, C is a hydrogen atom or together with D a carbon-carbon bond, D is a hydrogen atom or together with C a carbon-carbon bond, E is a hydrogen atom or together with F a carbon-carbon bond, F is a hydrogen atom or together with E a carbon-carbon bond, or an addition salt with a pharmaceutically acceptable acid.