Antioxidant effect of Korean traditional lotus liquor (Yunyupju)

This study presented the antioxidant activities of the Korean traditional lotus liquor (Yunyupju) made from lotus blossom and leaves. The antioxidant activities are dose-dependent and reached a plateau (about 80% inhibition) when the concentration of lotus liquor exceeded 25 μg in a modified linoleic acid peroxidation induced by haemoglobin. The concentrations to attain one absorbance unit at 700 nm were 23.6 ± 1.2 μg for Butylated hydroxytolene (BHT), and 45.7 ± 5.4 μg for lotus liquor. The scavenging activities of DPPH exerted by lotus liquor as well as α-tocopherol were tested. Linear response curves were also obtained and the IC₅₀ were estimated as 5.6 μg for α-tocopherol, 17.9 μg for lotus liquor. The maximum scavenging activity on hydroxyl radicals (40%) could be achieved when lotus liquor was more than 500 μg. Lotus liquor also has a potent superoxide radical scavenging activity, with value of 0.93 unit mg^-1 as superoxide dismutase equivalents. The IC₅₀ was estimated as 1.07 ± 0.04 mg for lotus liquor. The high performance liquid chromatography analysis of polyphenols was successfully achieved as these compounds appeared at 16.30 (catechin), 21.87 (rutin), 25.88 (unidentified peak), 31.51 (quercitrin), 35.19 (myricetin), and 36.72 (quercetin) min after injection of the sample, respectively.