Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy , University of Houston , 1441 Moursund Street , Houston , Texas 77030 , United States.
Department of Chemistry, College of Natural Sciences and Mathematics , University of Houston , 4800 Calhoun Road , Houston , Texas 77004 , United States.
J Agric Food Chem. 2018 Jun 20;66(24):6042-6052. doi: 10.1021/acs.jafc.7b04464. Epub 2018 Jun 8.
Raw264.7 is a murine macrophage-like cell line commonly used to study the anti-inflammatory efficacy of natural compounds. However, the impacts of long-time incubation on the tested compounds are often inappropriately ignored. Among 77 natural phenolic compounds (mainly flavonoids), only 36 remain more than 70% after a 15-h incubation in cell culture medium at 37 °C. Interestingly, for those compounds with a relatively good chemical stability, the presence of Raw264.7 cells could accelerate their disappearance in the medium, indicating that cellular metabolism occurred. As a representative phenolic, hesperetin was found to be efficiently metabolized by Raw264.7 cells and the metabolite was identified as a glucuronide in the further investigation. The glucuronidation activity is constitutive in this cell line. At certain concentration levels of hesperetin, the ability of hesperetin to inhibit PGD production in LPS-induced Raw264.7 cells was significantly enhanced by introducing β-glucuronidase, which can hydrolyze hesperetin glucuronide, into the incubation medium. The results indicate that glucuronidation and excretion of hesperetin can significantly impact its bioactivity in Raw264.7 cells.
Raw264.7 是一种常用于研究天然化合物抗炎功效的鼠源巨噬细胞样细胞系。然而，人们往往忽略了长时间孵育对受试化合物的影响。在 77 种天然酚类化合物（主要为类黄酮）中，只有 36 种在 37°C 细胞培养液中孵育 15 小时后仍保留超过 70%。有趣的是，对于那些化学稳定性相对较好的化合物，Raw264.7 细胞的存在会加速它们在培养基中的消失，表明发生了细胞代谢。以代表性酚类化合物橙皮素为例，研究发现其可被 Raw264.7 细胞有效代谢，进一步研究鉴定该代谢物为橙皮素葡萄糖醛酸苷。该葡萄糖醛酸苷化活性是该细胞系的固有特性。在一定浓度的橙皮素水平下，将能够水解橙皮素葡萄糖醛酸苷的β-葡萄糖醛酸酶引入孵育培养基中，可显著增强橙皮素抑制脂多糖诱导的 Raw264.7 细胞中 PGD 产生的能力。这些结果表明，橙皮素的葡萄糖醛酸化和排泄会显著影响其在 Raw264.7 细胞中的生物活性。
