QOL Division, Kaneka Corporation, Kita-ku, Osaka, Japan.
Nutr Res. 2010 Jan;30(1):74-81. doi: 10.1016/j.nutres.2009.12.005.
Licorice flavonoid oil (LFO) is a new functional food ingredient consisting of hydrophobic licorice polyphenols in medium-chain triglycerides. Recently, it was reported that licorice and its derivatives have anticarcinogenic activity in some types of tumors. However, the anticarcinogenic activity has not been identified in the liver, which is a major target organ for carcinogenesis in human. Therefore, we hypothesized that LFO has antihepatocarcinogenic activity, and we tested this hypothesis using the rat medium-term liver bioassay for carcinogens. Six-week-old male F344 rats (15 animals/group) received N-diethylnitrosamine (200 mg/kg by intraperitoneal injection) to initiate carcinogenesis. From the second week after initiation, animals received a 6-week regimen of either LFO concentrate solution (0, 150, 300, or 600 mg/kg) intragastrically or phenobarbital sodium salt in the diet (500 ppm) as a positive control. During the third week after initiation, animals were subjected to a two-thirds partial hepatectomy. During the eighth week of the treatment period, liver samples were taken from animals and examined immunohistochemically for expression of glutathione S-transferase placental form. No increase in the number of glutathione S-transferase placental form-positive liver foci was observed in all LFO groups compared with the negative control (solvent) group, and the number of foci in the 600 mg/kg LFO group was significantly lower than that in the negative control group. These results indicate that LFO concentrate solution has a significant inhibitory effect on liver carcinogenesis at 600 mg/kg.
甘草类黄酮油（LFO）是一种新型的功能性食品成分，由中链甘油三酯中的疏水性甘草多酚组成。最近有报道称，甘草及其衍生物在某些类型的肿瘤中具有抗癌活性。然而，在肝脏中尚未确定其抗癌活性，肝脏是人类致癌作用的主要靶器官。因此，我们假设 LFO 具有抗肝癌活性，并使用大鼠中期肝脏致癌物生物测定对此假说进行了检验。6 周龄雄性 F344 大鼠（每组 15 只）接受 N-二乙基亚硝胺（通过腹腔注射 200mg/kg）进行致癌作用诱导。在诱导后的第二周，动物开始接受为期 6 周的 LFO 浓缩溶液（0、150、300 或 600mg/kg）灌胃或饮食中添加苯巴比妥钠盐（500ppm）作为阳性对照。在诱导后的第三周，动物接受三分之二部分肝切除术。在治疗期的第八周，从动物中取出肝组织并通过免疫组织化学法检测谷胱甘肽 S-转移酶胎盘形式的表达。与阴性对照（溶剂）组相比，所有 LFO 组的谷胱甘肽 S-转移酶胎盘形式阳性肝灶数量均无增加，并且 600mg/kg LFO 组的灶数量明显低于阴性对照组。这些结果表明，LFO 浓缩溶液在 600mg/kg 时对肝癌发生具有显著的抑制作用。
