Author(s):
Pereira, Olívia R. 
; Perez, Maria J. ; Macias, Rócio I.R. ; Marín, Jose J.G. ; Cardoso, Susana M.
Date: 2013
Persistent ID: http://hdl.handle.net/10198/8808
Origin: Biblioteca Digital do IPB
Subject(s): Lamiaceae plants; Antioxidant activity; DPPH scavenging; Reducing power; ROS scavenging; HepG2 cell line
Description
In the last decades, oxidative stress has been recognized as a key process in the physiopathology of several diseases. Consequently, the search for new antioxidant compounds, as well as new antioxidant sources, has increased exponentially. The Lamiaceae family encloses many plant species which are potential sources of antioxidant compounds. The present study evaluates the antioxidant activity of phenolic enriched extracts of Lamium album, Leonurus cardiaca, Lavandula dentata, Mentha aquatica and Thymus citriodorus. The antioxidant activity of the hydroethanolic plant extracts was estimated by the in vitro measurement of their 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) scavenging potential and reducing power assays. Additionally, the protective effects of the extracts against the potassium dichromate (DK)-induced generation of reactive oxygen species (ROS) in human hepatoblastoma HepG2 cells were measured by flow cytometry, after a 48 h treatment period. The two chemical assays indicated that the extracts possess high antioxidant activity with the order of potency M. aquatica > L. album > L. dentata > T. citriodorus > L. cardiaca. EC50 values ranged from 8.1 to 18.3 μg/mL, and from 51.9 to 94.7 μg/mL for DPPH scavenging and reducing power assays, respectively. Moreover, with the exception of L. cardiaca, at 50 μg/mL, all the extracts induced an effective protection against the DK-induced generation of ROS in HepG2 cells. This protection was approximately 20% and 30%, for DK exposure at 5 and 25μM, respectively. The present data suggest that the herein studied plants can be applied as antioxidant agents.
