Evaluation of antioxidant capacity, total phenolic compounds and vitamin C content of some watercress (Nasturtium Officinale L.) populations of Iran

Watercress (Nasturtium Officinale L.) is a perennial member of the Brassicaceae family. Previously، it has been revealed that oral administration of this plant has a significant effect on diabetic rats and they have also contained the lower level of serum triglyceride indicating the anti-diabetic properties of the plant. The present study was aimed to introduce the best watercress population in terms of the highest antioxidant activity and total phenolic and vitamin C content for application in relevant industries such as pharmaceutical. In this study total phenolic and vitamin C content of different watercress populations were determined and their antioxidant activity was studied using the DPPH method. According to the results، Fashand (Alborz province) and Meimeh (Ilam province) exhibited the highest and the lowest antioxidant activity with the IC50 values of 70. 1 and 375 (µ g/ml)، respectively. The positive correlation observed in this study between the level of phenolic compounds and ascorbic acid and antioxidant activity of tested samples indicates that the use of DPPH free radicals is one appropriate method for evaluation of antioxidant activity of methanol extracts. Watercress has a high level of antioxidant activity and Fashand population may be considered as the population with the highest antioxidant activity among tested populations.