Free Radical Scavenging and Lipid Peroxidation Inhibition Potential of Hygrophila auriculata

Hygrophila auriculata (K. Schum.) Heine is a wild herb commonly found in moist places on the banks of tanks, ditches and paddy fields throughout India and is one of the main sources of Ayurvedic 'Rasayana' drug. The free radical scavenging potential of 50% aqueous alcoholic extract of H. auriculata (HAEt) was studied for DPPH scavenging activity, nitric oxide, hydroxyl radical and ferryl bipyridyl complex scavenging activity along with lipid peroxidation and total antioxidant capacity inhibition using Thiobarbituric acid reactive substances (TBARS) in rat liver homogenate. Integral antioxidative capacity was determined by photochemiluminescence assay. HAEt showed good radical scavenging activity at various concentrations $(200-1000\;{\mu}g/ml)$ against 1,1 diphenyl, 2-picrylhydrazyl (DPPH) (32.32-77.02%) with moderate scavenging activity against Nitric oxide (12.46-52.84%), hydroxyl radical (11.69-55.26%), ferryl bipyridyl complex (17.66-58.67%) and lipid peroxidation (0.829-0.416nmoles/mg protein). The above results indicate HAEt to be very effective antioxidant. It was suggested that the varied therapeutic activities claimed for the plant in the Indian indigenous systems of medicine may be in the part due to the free radical scavenging and/ or potent antioxidant activity.