Reacting active species induced oxidative damage of cellular tissue cause to many human diseases like cancer, cardiovascular disease, nephropathy and aging. Naturally occurring antioxidant supplements from plants are vital to counter the oxidative damage in cells. Recently, attention has focused on phytochemicals as new sources of natural antioxidants. Therefore, the main objective of the present study was to investigate the in-vitro antioxidant potential of methanolic extract of Lepidium sativum L seeds. In vitro antioxidant activity including 1,1-Diphenyl-2- picrylhydrazyl (DPPH) radical scavenging, Hydrogen peroxide scavenging and Reducing power scavenging. Percentage inhibition and IC50 were calculated. Preliminary phytochemical screening indicated that L. sativum possesses alkaloids, volatile oil and phenolic and flavonoids. In the present investigation, quantitative estimation of flavonoids and phenols was also carried out by colorimetric methods, using aluminum chloride method and Folin Ciocalteu reagent respectively. The extract showed significant activities in all antioxidant assays compared to the standard antioxidant in a dose dependent manner and remarkable activities to scavenge reactive oxygen species may be attributed to the high amount of hydrophilic phenolics. The IC50 values of all parameters were determined while ascorbic acid was used as standard. The results obtained in the present study revealed that L. sativum extract posses potent antioxidant activity.
