Maeta Akihiro, Okamoto Yuka, Ishikawa Honoka, Matsunaga Tetsuro, Takahashi Kyoko
Department of Food Science and Nutrition, School of Food Science and Nutrition, Mukogawa Women's University, 6-46, Ikebiraki-Cho, Nishinomiya, Hyogo, 663-8558, Japan.
Plant Foods Hum Nutr. 2025 Jan 7;80(1):32. doi: 10.1007/s11130-024-01257-9.
Burdock, Arctium lappa Linn. (Asteraceae), is cultivated in East Asian for its edible roots, and its seeds are used in a herbal medicine. Burdock seeds and roots exhibit anti-adipogenic activity. However, the anti-adipogenic activity of the aboveground parts of burdock remains underexplored. Therefore, this study determined the anti-adipogenic effects of burdock leaf extract on 3T3-L1 adipocytes. Seventy percent ethanol (EtOH) extract of burdock leaves, which inhibited lipid accumulation, was fractionated into five fractions using Diaion HP-20. EtOH eluted fractions (40 and 80%) strongly inhibited lipid accumulation. A common compound in these fractions was onopordopicrin (OPP), and purified OPP suppressed lipid accumulation and inhibited adipocyte differentiation. α, β-unsaturated carbonyl structure of OPP suggests potential electrophilic reactivity with polyfunctional thiol-trapping agents like cysteine residues. Indeed, the anti-adipogenic effects of OPP disappeared with the addition of cysteamine, which possesses a thiol group. Rhodamine-maleimide assay showed that OPP binds to the cysteine residues of adipocyte-specific transcription factor, peroxisome proliferator-activated receptor γ (PPARγ). Hence, our findings suggest that OPP exerts its anti-adipogenic action via binding to cysteine residues in signal proteins like PPARγ, inhibiting their activation. Thus, burdock leaf extract is a potential source of OPP, a bioactive compound with anti-obesity activity.
牛蒡，牛蒡（菊科），在东亚因其可食用的根而被种植，其种子被用于草药。牛蒡种子和根具有抗脂肪生成活性。然而，牛蒡地上部分的抗脂肪生成活性仍未得到充分研究。因此，本研究确定了牛蒡叶提取物对3T3-L1脂肪细胞的抗脂肪生成作用。用Diaion HP-20将抑制脂质积累的牛蒡叶70%乙醇（EtOH）提取物分离为五个部分。EtOH洗脱部分（40%和80%）强烈抑制脂质积累。这些部分中的一种常见化合物是土木香苦素（OPP），纯化的OPP抑制脂质积累并抑制脂肪细胞分化。OPP的α，β-不饱和羰基结构表明其与多官能团硫醇捕获剂如半胱氨酸残基具有潜在的亲电反应性。事实上，加入具有硫醇基团的半胱胺后，OPP的抗脂肪生成作用消失。罗丹明-马来酰亚胺测定表明，OPP与脂肪细胞特异性转录因子过氧化物酶体增殖物激活受体γ（PPARγ）的半胱氨酸残基结合。因此，我们的研究结果表明，OPP通过与PPARγ等信号蛋白中的半胱氨酸残基结合发挥其抗脂肪生成作用，抑制它们的激活。因此，牛蒡叶提取物是具有抗肥胖活性的生物活性化合物OPP的潜在来源。
