Protective role of Panax ginseng extract on lipid peroxidation and antioxidant status in polyethylene glycol induced Spathiphyllum leaves

The aim of this study was to examine the possible antioxidant capacities of tissue cultured mountain ginseng (TCMG) root extract in acclimatised and potted plants of Spathiphyllum cannifolium, stressed by the application of polyethylene glycol (PEG). Plants were treated with 0% PEG (control), 10% PEG and 10% PEG plus with TCMG (63.5 mg/kg day) for a period of 10 and 20 days. The TCMG root extract was supplemented (63.5 mg/kg everyday) and the levels of thiobarbituric acid reactive substances (TBARS), hydrogen peroxide (H2O2) and antioxidant enzymes were estimated in PEG induced S. cannifolium. PEG treated plants showed an induced accumulation of TBARS resulting in an inhibition of CAT, GR, GPx and GST activity indicating a clear oxidative stress. A significant increase in the activities of SOD, APX, G-POD, GPx, was observed in the leaves supplemented with TCMG root extract in PEG induced S. cannifolium indicating the ability of TCMG root extracts to ameliorate stress conditions. PEG treated plants reduced photosynthetic efficiency (Fv/Fm), indicating a down-regulation of photosynthesis of plant. Net CO2 uptake (A), stomatal conductance (g), transpiration rate (E), relative water content (RWC) and leaf osmotic potential (LOP) were also reduced in PEG-treated plant. However, these parameters were well protected in plants treated with PEG plus TCMG root extract treated plant. These results confirm the effectiveness of TCMG root extract supplementation in detoxifying oxidative damage, which is produced excessively in PEG-induced S. cannifolium. Therefore, roots of Panax ginseng are considered as a good source of antioxidant and can be produced on a large scale and, probably useful for human health.