Abstract:

In this paper, we develop an optimized procedure for the microwave-aided extraction of total flavonoids from mistletoe and test their in vitro scavenging activity against DPPH and hydroxyl (generated in Fenton system) free radicals. The optimization of the procedure for total flavonoids extraction was carried out using single factor and orthogonal array methods, in which the effects of extraction conditions on total flavonoids yield from mistletoe were evaluated. The results showed that the optimum conditions for total flavonoids extraction were as follows: ethanol concentration 70%, microwave power 500 W, solidto- liquid ratio 1:40 (g/mL) and extraction temperature 70 ℃. Under these conditions, the extraction yield of total flavonoids from mistletoe was up to 1.88%. The IC50 values of the extracted total flavonoids for DPPH and hydroxyl free radicals were 0.036 mg/mL and 0.572 mg/mL, respectively. Based on these results, it can be concluded that mistletoe total flavonoids is a promising free radical scavenger and that the developed extraction procedure is simple and convenient and consequently, is most suitable for large-quantity industrial production of mistletoe total flavonoids.

Key words: mistletoe, total flavonoids, procedure, free radical scavenging activity