Evaluation of three methods for the extraction of antioxidants from leaf and aerial parts of Lythrum salicaria L. (Lythraceae)

Lythrum salicaria L. (Lythraceae) known as purple loosestrife used for its beneficial health effects against as many human diseases such as diarrhea, hemorrhoid, eczema internally and/ or externally. The effects of the different extracting methods on the total phenolic (TP) and total flavonoid (TF) contents of Lythrum salicaria L. extracts were investigated. Dried leaf and flower of L. salicaria were extracted with three different methods (percolation method, ultrasonic assisted extraction and polyphenol fraction). The antioxidant activities of extracts were investigated by different methods, i.e. 1,1-diphenyl2-picryl hydrazyl radical (DPPH), nitric oxide and hydrogen peroxide scavenging activities as well as reducing power using standard methods. Phenol and flavonoid contents were also determined as gallic acid and quercetin equivalents, respectively. Extracts exhibited good antioxidant activity in all test models. In general, flower showed better activity than leaf extracts. Ultrasonic extract of flower showed the best activity in scavenging of hydrogen peroxide but polyphenol fraction was the more potent one in other tests. Its higher phenolic and flavonoid contents could be responsible for its antioxidant activity.