啤酒花多酚提取物体内外抗氧化活性研究

从酿造废酒花（Humulus lupulus L.）中提取制备一种高纯度（总多酚含量为88.7%）的酒花多酚提取物（hop polyphenol extract，HPE），测定其酚类组成成分与体内外抗氧化活性。结果表明：HPE中55%以上的多酚物质是原花青素，28%以上的多酚物质是黄酮苷类。在体外，HPE能有效清除活性氧自由基，显著抑制Cu2+-VC诱导的DNA氧化断裂损伤。在体内，口服200～800 mg/kg（以体质量计）多酚剂量的HPE可显著抑制因溴代苯诱导的小鼠肝脏超氧化物歧化酶和谷胱甘肽过氧化物酶活性的降低，也可降低溴代苯氧化应激小鼠肝脏的硫代巴比妥酸产物含量。结论：膳食摄入HPE可提供体内外抗氧化损伤的保护作用，酒花多酚的体内外抗氧化效果均优于同质量浓度的绿茶多酚。

in vitro and in vivo Antioxidant Activities of Polyphenols Extracted from Hops (Humulus lupulus L.)

A high-purity hop polyphenol extract (HPE) (containing 88.7% of total phenolics) was prepared from spent hops in
the present study. The phenolic compositions of HPE were determined and its in vivo and in vitro antioxidant activities were
evaluated by comparison with those of green tea polyphenols. The results showed that the phenolic compositions of HPE
included more than 55% proanthocyanidins and more than 28% flavonoid glycosides. in vitro, HPE effectively scavenged
reactive oxygen species and inhibited Cu2+ vitamin C-induced oxidative DNA damage. in vivo, orally administered HPE at
polyphenol doses of 200 to 800 mg/kg body weight significantly prevented a bromobenzene-induced decrease in hepatic
superoxide dismutase and glutathione peroxidase activity, and decreased the levels of hepatic thiobarbituric acid reactive
substance in bromobenzene-treated mice. HPE at the oral doses of 200 to 800 mg/kg body weight significantly reduced the
frequency of bone marrow micronuclei induced by cyclophosphamide. These results suggest that dietary hop polyphenols
could provide protection from oxidative mutagenic in vivo and in vitro damage. The in vivo and in vitro antioxidant activities
of hop polyphenols were higher than those of green tea polyphenols at the same concentration.