Chemistry and functional properties in prevention of neurodegenerative disorders of five Cistus species essential oils.

The chemical composition of Cistus creticus, Cistus salvifolius, Cistus libanotis, Cistus monspeliensis and Cistus villosus essential oils has been examined by GC and GC-MS analysis. Height-nine constituents were identified in C. salvifolius oil, sixty in C. creticus, fifty-six in C. libanotis, fifty-four in C. villosus, forty-five in C. monspeliensis. Although the five species belong to the same genus, the composition showed interesting differences. Essential oils were screened also for their potential antioxidant effects (by DPPH, ABTS, FRAP and β-carotene bleaching test) and their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity, useful for prevention and treatment of Alzheimer's disease. C. monspeliensis exhibited the most promising activity in β-carotene bleaching test (IC₅₀ of 54.7 μg/mL). In FRAP test C. libanotis showed a value of 19.2 μM Fe(II)/g. C. salvifolius showed the highest activity against AChE (IC₅₀ of 58.1 μg/mL) while C. libanotis, C. creticus, C. salvifolius demonstrated a good inhibitory activity against BChE with IC₅₀ values of 23.7, 29.1 and 34.2 μg/mL, respectively. Overall our results could promote the use of the essential oil of different Cistus species as food additives and for formulation of herbal infusion or nutraceutical products.