Pollution of agricultural soil by alkaline salts, such as Na2CO3, is a critical and long-lasting problem in cultivable land. The aim of the study was to examine the putative role of citric acid (CA) in alleviating Na2CO3-stress in alfalfa. In this study, Na2CO3 significantly induced leaf chlorosis, inhibited plant growth and photosynthesis related parameters, increased hydrogen peroxide (H2O2) and reduced major antioxidant enzymes (SOD ,CAD, APX) in alfalfa. However, the presence of CA these negative effects of Na2CO3-stress largely recovered. Interestingly, expression of antioxidant and ion transporter genes (Fe-SOD, CAT, APX, DHAR and NHX1) involved in Reactive oxygen species (ROS) homeostasis and oxidative stress tolerance in alfalfa. These findings suggest that CA-mediated Na2CO3 stress alleviation is an ecofriendly approach that would be useful to local farmer for alfalfa and other forage crop cultivation in alkaline soils.

Intracellular reactive oxygen species(ROS) produced in a various pathologic state was known to intermediate many cellular response such as inflammation. Recently, low level light irradiation by HeNe laser used in many clinical field could improve inflammatory state by scavenging intracellular ROS through photo-detachment/dissociation process. The purpose of this study is to investigate the differential effects of blue and red light irradiation on ROS scavenging effects. Immortalized human oral keratinocyte HaCat cells were used. Phorbol 12-myristate 13-acetate(PMA) was treated for inflammation. Red(635nm) and blue(470nm) light irradiation was carried out. To asses the intracellular ROS by light irradiation, confocal microscopic and flow cytometric assay with DCF fluorescence for total ROS and ESR spectrometry of DMPO-O2 - for superoxide anion were caried out. And microarray was performed for mRNA expression level. Released intracellular total ROS in PMA treated HaCat cell lines was dissociated efficiently by red light irradiation, while blue light irradiation did not. Rather, blue light irradiation increased ROS formation. For superoxide anion generated the first synthetic form of ROS, red light irradiation reduced its amount but blue light irradiation did not. In the mRNA expression in line with cyclooxygenase(COX) pathway, prostagrandin endoperoxide synthase 1(PTGS 1), prostagrandin endoperoxide synthase 2(PTGS 2) and phospholipase A2(PLA2) were increased by both light irradiation and they were decreased as time flows. And genes associated with ROS releasing, mRNA expressions of tumor necrosis factor receptor (TNFR) and interleukin 1beta(IL1B) were increased by 1 hour red light irradiation but did not by blue light irradiation. As a result, red and blue light irradiation showed different response in affecting the level of ROS. These findings indicate that red light rather than blue light is more useful for anti-inflammation in clinical field

The propose of this study was to investigate the antioxidant activity of 80% ethanol extracts and various solvent fractions of dandelion (Taraxacmn officinale) leaves and roots, Total phenolics and phenolic acid contents were also examined. The total phenol content of leaves and roots were and respectively. Eight phenolic acids were separated by GC, among which caffeic acid (113.7 mg%)and m-coumaric acid (152.6 mg) were the dominant phenolic acids in leaves and roots, respectively. Amongst solvent functions of leaves and roots, the ethyl acetate fraction showed the strongest radical scavenging activity. A strong correlation was found between total phenol content and electron-donating ability, and ABTS radical scavenging activity showed a similar trend as electron-donating ability. Hydroxyl-radical-scavenging activity and lipid peroxidation were significantly higher in the ethyl acetate fraction than other factions. In particular, the SOD-like activity was highest (43.6%) in the ethyl acetate fraction of dandelion leaves, and was higher than that of trolox. Thus, the ethyl acetate fraction of dandelion leaves exhibited significant phenol content, antioxidant activity, and free-radical-scavenging effects.