HPLC Analysis of Polyphenolic Compounds and Antioxidant Activity in Nasturtium officinale

The antioxidant activities of crude extract, dichloromethane, ethyl acetate, and butanolic fractions of Nasturtium officinale were investigated using the 1,1,-diphenyl-2-picryl-hydrazyl and thiobarbitaric acid reactive species methods. Total phenolics and flavonoids were determined. Rutin, chlorogenic, and caffeic acids were quantified in the crude extract by high performance liquid chromatography-photodiode array detector. The antioxidant and radical scavenging activity of the crude extract and fractions were found in the following decreasing order: butanolic fraction > ethyl acetate fraction > dichloromethane fraction > crude extract. The extent of antioxidant activities was in accordance with the amounts of phenolics and flavonoids present in the extract and fractions. Ethyl acetate and butanolic fractions caused a sharp fall in thiobarbitaric acid reactive species production, starting at the concentration of 1 μg/mL for both fractions with IC50 6.92 ± 0.19 and 12.07 ± 0.45 μg/mL, respectively. N. offi...