Neuroprotective compounds and pharmaceutical compositions comprising them

A method for preventing or treating neurone deteriorations in an individual, comprising administering to said individual a prophylactically or therapeutically effective quantity of at least one compound having neuroprotective activity of the following formula (I):

• in which:
• a represents 0 or 1,
• b represents a single bond or a double bond,
• c represents a single bond or a double bond,
• d represents 0 or 1,
• X represents an oxygen or nitrogen atom, provided that when X represents an oxygen atom then d has the value of 0 and when X represents a nitrogen atom then d has the value of 1,
• R1, R2, R3, and R4, which are the same or different, represent a hydrogen atom, a halogen atom, in particular selected from F, Cl, Br, or I, a hydroxyl group, or an alkoxyl group having 1 or 2 carbon atoms,
• R5 and R6, which are the same or different, represent a hydrogen atom, an alkyl or cycloalkyl group having 1 to 6 carbon atoms, or an aryl group having 6 carbon atoms in which the aromatic ring may be substituted by one or more halogen atoms or one or more hydroxyl groups, alkoxyl having 1 or 2 carbon atoms, trifluoromethyl or nitro,
• R7 represents a hydrogen atom, a hydroxyl group, or an alkyl or hydroxyalkyl group having 1 to 3 carbon atoms,
• R8 represents an oxygen atom or a —NR9R10, R9 and R10 group, which are the same or different, representing a hydrogen atom, a hydroxyl group, or an alkyl or hydroxyalkyl group having 1 to 3 carbon atoms, provided than when R8 represents an oxygen atom then a has the value 1, b represents a single bond and c represents a double bond and that when R8 represents a —NR9R10 group then a has the value 0, b represents a double bond and c represents a single bond,
• or their pharmaceutically acceptable salts.