Effect of ethanol concentrations and extraction time on acanthoside-D and total polyphenol contents and antioxidant activities in ethanol extracts of eleuthero

Abstract

Eleutherococus senticosus has been used as a traditional medicine with tonic and sedative effects. Preliminary data would be necessary for eleuthero products to find out better biological functions. The effect of ethanol concentration and extraction time on the contents of acanthoside-D, polyphenols and antioxidant activities in ethanol extracts of eleuthero (Eleutherococus senticosus) was evaluated to provide preliminary data for making eleuthero products that may have better biological functions. Bark of eleuthero stem was cut into 0.5 cm long pieces, which were then put in 20, 40, 60 or 80% ethanol (75 g in one L ethanol) and stored for 30, 60 and 90 days at room temperature. Acanthoside-D content in the ethanol extracts from eleuthero (EEE) extracted in 40% ethanol was higher than those in the other samples (p<0.05). Total polyphenol content (TPC) in the EEE extracted in 20 and 40% ethanol were significantly less than in the others on the 60th day (p<0.05). Extracting time had little influence on the acanthoside-D content and TPC in the EEE. Antioxidant activities of the EEE, determining DPPH and ABTS free radical scavenging activities were not significantly different among the samples regardless of ethanol concentration and extracting time. The eleuthero extracts with the initial ethanol concentrations of more than 40% had generally more acanthoside-D contents and total polyphenols and stronger antioxidant activities than the others. Extracting time little influenced on them in the EEE.