Application of green-extraction technique to evaluate of antioxidative capacity of wild population of fireweed (Epilobium angustifolium)

Introduction: Fireweed (Epilobium angustifolium (L.) Holub) is a common weed growing on meadows, roadside and agricultural wasteland, creating vast, rapidly spreading fields. Objective: The aim of the study was to evaluate the antioxidant activity of extracts from fresh fireweed, harvested at three ripening stages. Methods: Analysis of antioxidative activity was carried out by DPPH, ABTS and FRAP methods. Total polyphenol and total flavonoid content were also determined. Plant material was extracted using ultra-sound-assisted green extraction technique with methanol, ethanol and isopropanol at different concentrations and water. Results: The highest antioxidant activity evaluated by DPPH, ABTS and FRAP was found for the extracts prepared in 70% ethanol. The highest content of total polyphenols were observed in extracts in 70% ethanol, whereas the highest content of flavonoids extracts in undiluted methanol. Conclusion: Epilobium angustifolium harvested at fruit ripening stage seems to be a valuable source of antioxidants.