Nakanishi Masayuki, Hino Mami, Yoshimura Morio, Amakura Yoshiaki, Nomoto Hiroshi
Laboratory of Biochemistry, College of Pharmaceutical Sciences, Matsuyama University, Matsuyama, Ehime, 790-8578, Japan.
Laboratory of Biochemistry, College of Pharmaceutical Sciences, Matsuyama University, Matsuyama, Ehime, 790-8578, Japan.
Exp Parasitol. 2019 May;200:24-29. doi: 10.1016/j.exppara.2019.03.008. Epub 2019 Mar 18.
Cases of human African trypanosomiasis caused by infection with a protozoan parasite, Trypanosoma brucei, are decreasing due to enhanced surveillance and control. However, effective and safe treatments for this disease are still needed. In this study, we investigated the antitrypanosomal activity of citrus fruit peel. When 19 citrus cultivars were examined for activity against T. brucei in vitro, significant activities were observed in four closely related cultivars and a distantly related one. Among these five cultivars, "Setoka" was selected for identification of its active components due to exhibiting the highest activity. Solvent extraction and gel filtration followed by preparative thin-layer chromatography succeeded in isolating two compounds exhibiting ICs of 4.8 and 2.4 μg/mL, respectively. The spectral data of these two compounds were well consistent with those of sinensetin and nobiletin belonging to the class of polymethoxyflavones. Authentic compounds also showed similar ICs. These results indicate that the two polymethoxyflavones are the major active components involved in the inhibition of T. brucei proliferation and are abundant in Setoka cultivar peel compared with the levels in the other cultivars. Setoka peel and the naturally occurring polymethoxyflavones might serve as dietary components imparting resistance to T. brucei.
由于监测和控制的加强，由原生动物寄生虫布氏锥虫感染引起的人类非洲锥虫病病例正在减少。然而，仍需要针对这种疾病的有效且安全的治疗方法。在本研究中，我们调查了柑橘类水果果皮的抗锥虫活性。当检测19个柑橘品种对布氏锥虫的体外活性时，在四个亲缘关系密切的品种和一个亲缘关系较远的品种中观察到了显著活性。在这五个品种中，“濑户佳”因其表现出最高活性而被选来鉴定其活性成分。通过溶剂萃取、凝胶过滤，然后进行制备型薄层色谱，成功分离出两种化合物，其半数抑制浓度分别为4.8和2.4μg/mL。这两种化合物的光谱数据与多甲氧基黄酮类的橙皮素和川陈皮素的数据高度一致。标准化合物也显示出类似的半数抑制浓度。这些结果表明，这两种多甲氧基黄酮是抑制布氏锥虫增殖的主要活性成分，与其他品种相比，它们在濑户佳品种的果皮中含量丰富。濑户佳果皮和天然存在的多甲氧基黄酮可能作为赋予对布氏锥虫抗性的膳食成分。
