Assessment of Protective Effects of Methanolic Extract of Salvia verbenaca Roots Against Oxidative Damage Induced by Hydrogen Peroxide

Abstract

Salvia verbenaca is a medicinal plant that has been traditionally used in Algeria for the treatment of wounds and emptied abscesses. The present study aimed to evaluate the cytotoxicity of methanolic extract of S. verbenaca roots and explore its ability to bestow protection against oxidative damage induced by H2O2 (200 μM). The cytotoxic effects and protective properties of S. verbenaca on human monocytic leukemia cells (THP-1) was studied using thiazolyl blue tetrazolium bromide assay. The protective effects of the extract against H2O2-induced oxidative damage was evaluated using single cell gel electrophoresis (comet) assay and 2,7-dichlorodihydrofluorescien diacetate (H2DCFDA) assay. S. verbenaca extract was found to be non-cytotoxic at concentrations <500 μg/mL. However, the use of 500 and 1000 μg/mL of the extract decreasedcell viability. H2DCFDA assay provided evidence for anti-oxidative properties of S. verbenaca. Addition of S. verbenaca (1 and 10 μg/mL) resulted in significant reductionin H2O2-induced reactive oxygen species (ROS) production. Further, comet assay showed that addition of the extract resulted in a significant reductionin the length and % DNA content of comet tail. Additionally,nuclei in the cells also appeared to be devoid ofdegradation. The use of S. verbenaca root extract conferred protection against H2O2-induced ROS production and DNA breakage in vitro.