An in vitro approach to neuroprotective activity of Rosa damascena Mill., a medieval age traditional medicine used for memory enhancement

Abstract

Rosa damascena Mill. was recorded to be used traditionally for memory enhancement in the medieval age. Therefore, neuroprotective effect of the essential oil and aromatic waters of R. damascena was investigated by in vitro and in silico methods. The essential oil and its components (citronellol, geraniol, nerol, and phenylethyl alcohol), and two samples of the aromatic water (Eau de rose) of R. damascena were tested for their inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) at 100, 200, 500, and 1000µg/ml. Since oxidative damage is associated with neurodegeneration, antioxidant activity of the samples was determined by DPPH radical scavenging, metal-chelation, and ferric-reducing antioxidant power (FRAP) assays. Chemical composition of the samples was elucidated by GC-MS. The rose essential oil showed a noteworthy inhibition against AChE (60.86±1.99%) and BChE (51.08±1.7%) at 1000µg ml-1, whereas the aromatic waters did not have any inhibition. The essential oil exhibited moderate activity in antioxidant assays. Phenylethyl alcohol exerted higher cholinesterase inhibition than other components. None of the double and triple combinations of citronellol, geraniol, nerol, and phenylethyl alcohol could reach at inhibition level of phenylethyl alcohol. Phenylethyl alcohol was theoretically studied utilizing molecular docking simulations into the active site gorge of AChE and BChE and the data revealed that this compound is more selective towards BChE than AChE. Our findings confirmed traditional use of R. damascena for memory enhancement, which is suggested to come into view through mainly cholinesterase inhibition, and antagonistic interaction presumably exists between phenylethyl alcohol and other components.