Antioxidant Effects of Elsholtzia splendens Extract on DMBA-induced Oxidative Stress in Mice

The present study was conducted to investigate the effects of flowers ethanol extract of Elsholtzia splendens (ESE) on the antioxidant defence system in mice with 7,12-dimethylbenz(a)anthracene (DMBA)-induced oxidative stress. The ESE was pre-administered orally to 2 groups of mice at 10 and 50mg/kg body weight (BW) for 5 weeks. Subsequently, mice with pretreatment of ESE received DMBA intragastrically at a dose of 34 mg/kg BW twice a week for 2 weeks. In DMBA alone group, biomarkers of oxidative stress (TBARS value, carbonyl content, and serum 8-OH-dG) were significantly increased. Also, the antioxidant enzymes were down-regulated. ESE significantly restored the TBARS value and carbonyl content at both doses, while a decrease in the elevated serum 8-OH-dG content was observed only at the higher dose. The DMBA-induced decreases in catalase and superoxide dismutase (SOD) activities were restored to nearly control levels by ESE. Glutathione peroxidase (GSH-px) and glutathione reductase (GR) activities, as well as the reduced glutathione (GSH)/oxidized GSH (GSSG) ratio, were significantly affected by ESE at the higher dose. These results suggest that ESE possesses antioxidant activity, which plays a protective role against DMBA-induced oxidative stress.