Antioxidant and anticholinesterase activities of the essential oil of Eugenia dysenterica DC.

This paper describes the anticholinesterase and antioxidant activities of Eugenia dysenterica DC. (O. Berg. (Myrtaceae) essential oils from leaves (EOED). EOED were obtained by hydrodistillation using a Clevenger-type apparatus and the products were analyzed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detector (GC-FID). The main constituents of EOED were caryophyllene oxide (66.3%), isoledene (3.9%), 1,3,8-p-menthatriene (3.5%), mustakone (3.46%), β-phellandrene (1.7%), and selin-11-en-4-α-ol (1.7%). The antioxidant assay was performed based on the formation of thiobarbituric acid reactive substances (TBARS), hydroxyl radical, and nitric oxide production. By performing the Ellman assay, it was observed that EOED was able to inhibit the enzyme acetylcholinesterase (AChE) with an IC50 = 0.92 g.ml-1 promising better value when compared with the drug rivastigmine (IC50 = 1.87 g.ml-1), used in the treatment of Alzheimer's disease. The caryophyllene oxide (the main compound) was tested after purification on the AChE with an IC50 = 0.31 g.ml-1. Caryophyllene oxide (the majority compound) was tested on the AChE and presented the IC50 = 0.31 g.ml-1. At concentrations of 0.9, 1.8, 3.6, 5.4, and 7.2 g.ml-1, it was found out that EOED prevented lipid peroxidation inhibiting amount of TBARS formed in a similar manner to ascorbic acid. In addition, there was a reduction in the production of hydroxyl radical as well as the production of nitric oxide. To the best of our knowledge, this is the first report on compounds from   this species that have activity for potentially preventing neurodegenerative disorders. Key words: Eugenia dysenterica, essential oil, antioxidant, anticholinesterase.