Antioxidant activity, neuroprotective properties and bioactive constituents analysis of varying polarity extracts from Eucalyptus globulus leaves

Eucalyptus globulus is employed as herbal tea and therapeutical purposes. In this work, it is investigated for first time the neuroprotective activities, based on antioxidant properties, of varying polarity extracts (acetone, ethanol and methanol) from E. globulus leaves and elucidate their main bioactive constituents. Methanol and acetone extracts contained the highest phenolic compounds amount and chlorogenic acid was the major compound identified by UPLC-ESI-MS/MS. Moreover, the three tested extracts showed significant antioxidant properties, varying their potency depending on the in vitro technique used. Furthermore, E. globulus extracts were effective in ameliorating H2O2-induced oxidative stress by increasing cell viability, GSH levels and antioxidant enzymes activity and, by decreasing ROS production and lipid peroxidation levels in SH-SY5Y cells. Taken together, E. globulus leaves extracts could be used as raw material for food and pharmaceutical supplements for their high content in antioxidant compounds with health benefits properties against oxidative stress. Keywords: Eucalyptus globulus, Neuroprotection, Antioxidants, Bioactive constituent